GB1603117A

GB1603117A - Tools for fixing screw-threaded inserts

Info

Publication number: GB1603117A
Application number: GB1890977A
Authority: GB
Original assignee: INSTR SCREW CO Ltd
Current assignee: INSTR SCREW CO Ltd
Priority date: 1978-05-31
Filing date: 1978-05-31
Publication date: 1981-11-18

Description

(54) TOOLS FOR FIXING SCREW-THREADED INSERTS (71) We, THE INSTRUMENT SCREW COMPANY LIMITED. a British Company. of 206 Northolt Road, South Harrow, Middlesex, HA2 OET, do hereby declare the invention. for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to the fitting and securing in place of screw-threaded inserts in complementary screw-threaded bores provided in appropriate workpiece members.

More particularly. the invention concerns improved forms of tools suitable for use in the fitting and securing in place of thinwalled screw-threaded inserts of a kind, hereinafter termed "of the kind referred to" comprising a tubular body having internal and external screw threads and, adjacent one end. external teeth or serrations together with an internal counterbore. said counterbore providing a relatively thin annular wall portion which, when the insert has been screwed home into a flush fitting relationship in a complementary screwthreaded bore prepared in a workpiece member. is capable of being forcibly expanded radially outwards thereby to cause the external teeth or serrations to penetrate into the surrounding material of the workpiece member and thus to lock and firmly secure the insert in place.

Examples of such thin-walled screwthreaded inserts are described in Patent Specification No. 972814. together with some examples of various tools for driving them into the workpiece threaded bores and for expanding their externally toothed or serrated counterbore wall portions so as to fit and secure them in place.

The above-mentioned tools described in Patent Specification No. 972814 are of different kinds and are representative of the prior art tools used in conjunction with such inserts. Some of them have been designed specifically for carrying out only the single operation of driving the inserts into the workpiece bores whilst - some others have been designed specifically for carrying out only the single operation of expanding the counterbore wall portions after the inserts have been fitted in the workpiece bores, these two different kinds of tools being intended to be used separately, one after the other, in fitting and securing each insert.

And in addition, in another category, some of the tools have been designed to combine in the same tool structure both the functions of driving and expanding the inserts so that these tools can each be used for carrying out both operations necessary in fitting and securing the inserts in place.

All the prior art tools, however, have generally been designed primarily for engagement with the inserts after the latter have been already positioned in or opposite to the workpiece bores by a separate preliminary manipulating operation which, in practice, can sometimes be difficult or inconvenient.

Also, for carrying out the driving operation, the prior art tools have generally been designed with a spigot portion adapted, by means of a hexagonal cross-section or toothed profile for example, to engage and key with a plurality of internal longitudinal driving grooves specially provided within the bore of the inserts. In some cases, however, this arrangement for imparting a rotary drive to the inserts can involve some risk of damaging the internal screw threads and the necessity of providing the longitudinal driving grooves may be a disadvantage and lead to a significant weakness in the inserts, especially in small sizes.

For expanding the counterbore wall portions of the inserts, although several different forms of expanding means have been utilized in the design of the prior art tools, including swage elements or parts which are driven axially into the counterbores so as to engage the wall portions thereof with a wedge action and elements or parts which are introduced into the counterbores and which are then subjected to a radial expansion, the operation of the tools has generally required percussion or application of impact forces thereto as, for example, by striking or tapping with a hammer. The use of such impact forces is often quite acceptable, but sometimes it can be a disadvantage and in some circumstances it may lead to damage, especially if the workpiece members are composed of sensitive or soft alloys, and may not always be permissible.

For various reasons, including the disadvantages or potential disadvantages indicated above. it has accordingly now been appreciated that the existing prior art tools for fitting and securing such inserts are not always as satisfactory as may be desired and there is some scope and need for improvements or for alternative new structural and functional forms which may avoid or reduce one or more of the disadvantages and potential disadvantages of the prior art tools.

In a basic broad aspect. the present invention provides a tool for use in the fitting and securing in place of thin-walled screwthreaded inserts. of the kind referred to. in complementary screw-threaded bores prepared in workpiece members, said tool comprising a plurality of separate component parts which are assembled together and which provide: an elongate mandrel designed to be introduced into and to fit and locate co-axially within the screw-threaded bore of a said insert: an axial limit stop arranged to engage in abutting relationship with the insert when the tool is in use and the mandrel is properly fitted and located within the bore of said insert: a drive input member. co-axial with said mandrel. for receiving a rotary input drive from an external rotary drive source when the tool is in use for fitting said insert in a said prepared bore in a said workpiece member: means effective to transmit such input drive from the drive input member to the insert so as to cause the insert to be rotated. while the mandrel is properly fitted and located as aforesaid within the screwthreaded bore thereof. and thereby to enable said insert to be screwed home in said prepared bore in said workpiece member under an axial pressure. also provided or derived from said input drive. applied through said axial limit stop: and swage means operable to perform a swaging operation. during use of the tool after said insert has been screwed home in said bore of the workpiece member. to effect forcible expansion of said annular wall portion of the insert counterbore radially outwards for locking and firmly securing the insert in place; at least two said component parts of the tool being displaceable relative to one another in the axial direction in order to bring about said operation of said swage means.

The tool may be designed as a complete self-contained hand tool operable by drive manually applied directly thereto, the operator's hand then forming the external rotary drive source, and for this purpose the drive input member may form a handle or be provided with finger grip means. Or, alternatively, the tool may be designed as an attachment for use with a rotary driving implement. such as a hand-operated or power-operated drill, constituting the external rotary drive source with which said drive input member of the tool can be operatively engaged.

In some embodiments. the structure of the tool is such that relative axial movement and displacement of said relatively displaceable component parts, effective to operate the swage means and carry out the swaging operation, can be produced by axial pressure provided by or derived from a nonpercussive input drive applied for swaging after completing the screwing home operation of the insert in the workpiece bore. The tool may further be designed so that the swage means is operated by applying this non-percussive swaging input drive, in the form of a rotary and/or axial pressure drive, to the said drive input member from the same external rotary drive source as is utilized for screwing the insert whereby the screwing home operation and the swaging operation can be carried out consecutively without disengaging said external rotary drive source from said drive input member.

Alternatively, the tool may be designed so that the swage means is operated by a separate subsequent application of the nonpercussive swaging input drive to a different part of the tool independent of and movable relatively to said drive input member which receives the input drive for screwing the insert.

Or. in other embodiments. one of said relatively displaceable component parts of the tool may be designed for receiving a percussive axial input drive to an exposed end portion thereof to produce relative axial movement and displacement effective to operate the swage means.

The means for transmitting the input drive from the drive input member to the insert for the screwing operation may comprise. in one group of embodiments. an element or elements. operatively connected to said drive input member for rotation therewith, providing pressure surface por tions engageable frictionally with the counter-bored outer end portion of the insert located upon the mandrel which may be of plain cylindrical form also connected so as to rotate with the drive input member.Such pressure surface portions may also provide the axial limit stop but preferably they are adapted to engage the inner surface of the wal portion of the insert counterbore under a gripping pressure. directed radially outwards, which is derived from associated resilient biassing means, thereby to provide holding means effective to retain the insert in place after initially being fitted upon the mandrel before being applied to the workpiece bore, at which stage the mandrel functions as a carrier or mounting for the insert.

In another group of embodiments, the tool may be adapted to transmit the input drive to the insert for the screwing operation by the mandrel being operatively connected with the drive input member so as to rotate therewith and by providing the mandrel with a screw thread which matches and engages the internal screw thread in the bore of the insert, this screw thread on the mandrel acting to transmit the drive in conjunction with the axial limit stop. This mandrel screw thread also provides a holding means for retaining the insert in place, as mentioned above, permitting removal of the tool after the setting and fixing operations are completed by application of a rotary drive in a reverse direction.

By providing such screw thread on the mandrel together with an axial limit stop which is adapted for relative axial movement or displacement and which engages the surface of the workpiece adjacent to the bore when the insert is screwed home, the tool may be designed so that the subsequent swaging operation can be performed by continuing to apply a rotary input drive so as to cause the mandrel to screw into the insert, producing an axial displacement relative to the axial limit stop and generating thereby axial pressure required to operate the swage means. In such arrangements, the axial limit stop will generally be designed to abut against the end face of the insert with portions extending laterally outwards for engaging the workpiece surface. and it may be telescopically mounted for relative sliding movement upon a drive shaft portion connected to the mandrel.By spring loading such telescopically mounted axial limit stop.

it can readilv be designed to reset automatically after a swaging operation is completed and the tool is removed from the insert, but in other embodiments a specific resetting operation may be needed to reposition the limit stop relative to the insert before the tool is used again.

Instead of the tool being designed so that the screw-threaded mandrel is caused to screw into the insert during the swaging operation, it may alternatively be designed so that during the swaging operation no rotary drive is transmitted to the mandrel which remains stationary within the insert whilst other parts move axially relative thereto in operation of the swage means. In this case, the axial limit stop may be adapted for axial movement or displacement relative to the mandrel if it is also adapted to form part of the swage means acting to apply the swaging or radial expansion force to the insert counterbore wall portion during the swaging operation. But, in most preferred embodiments, the axial limit stop will not be relatively movable with respect to the mandrel and may be integral or rigidly connected in predetermined relationship therewith.

The axial limit stop may, for example, be provided by a tubular member surrounding and secured or locked to a drive shaft portion carrying the mandrel, this member having an annular end face forming a stop surface adapted to abut against the end face of the insert and also to engage the surface of the workpiece when the insert is screwed home into the bore therein, thereby automatically controlling the depth to which the insert is set within the workpiece bore.

Alternatively, in other examples the axial limit stop may be in the form of an integral collar adjacent the innermost end of the screw-threaded mandrel, this collar being adapted to fit within the counterbore of the insert and to engage the internal shoulder at the bottom thereof. This integral collar form of axial limit stop does not function to control the depth of insertion of the insert into the workpiece bore, but the exact depth of insertion is not always critical and can often be judged with sufficient accuracy by the eye of the operator for him to stop the screwing home operation at the appropriate instant.Or, the tool may include a second stop element arranged solely for engaging the surface of the workpiece when the insert is inserted to the correct depth to prevent further screwing in, this second stop being in fixed predetermined relationship to the collar forming the insert axial limit stop although, if desired, means may be provided for adjusting this fixed predetermined relationship in a preliminary pre-setting operation of the tool so that the depth of insertion can be controlled and varied according to requirements.

With the tool designed for the screwthreaded mandrel to remain stationary within the insert during the swaging operation, axial pressure to operate the swage means may be provided directly by an axial drive pressure or force input applied to the tool.

Alternatively, the tool may incorporate a manually operable mechanical device such as a lever mechanism for producing this axial pressure, or it may incorporate a mechanical means such as a cam device or arrangement which will produce or generate such axial pressure from a rotary drive input whilst the mandrel is held stationary within the insert through interaction with stop means engaging the workpiece surface.

For rotation during the first stage of screwing home the insert into the workpiece bore, the mandrel may be operatively connected to the drive input member positively by being formed integral with, or rigidly secured to, an intermediate drive shaft portion that is itself integral with, or rigidly connected to. the drive input member. Or, alternatively. the mandrel may be operatively connected to the drive input member, for rotation therewith, through a unidirectional or non-positive drive coupling or through clutch means which may include a spring-loaded frictional drive coupling.

The swage means will generally comprise a swage element or elements arranged to engage the insert internally within the counterbore so as to bear against the annular wall portion thereof with an outwards radial component of pressure to expand this wall portion during the swaging operation.

In many embodiments, the swage element or elements will be arranged to move axially relative to the insert during the swaging operation to engage the annular wall portion of the latter through a cam form swaging surface portion or portions providing the required outwards radial component of pressure. Where the mandrel also moves axially relative to the insert during the swaging operation. as when it is threaded and arranged to screw into the insert to generate the axial swaging pressure. a single such swage element may be provided which is integral with. or is otherwise arranged to move axially with. the mandrel. But. in other cases a single such swage element may be provided which is slidably mounted for axial movement, as for example in the form of a tubular member or sleeve telescopically mounted on a drive shaft portion connected to or carrying the mandrel.Means may also be provided for controlling the depth to which such a swage element penetrates into the counterbore of the insert, such as for example adjustment means which can be pre-set to vary the axial position of the swage element. at the end of its swaging stroke. relative to the insert axial limit stop.

In other embodiments. the swage elements or elements may be arranged to expand or move outwards radially within the counterbore of the insert during the swaging operation, in response to relative axial displacement of a swage actuating drive element co-acting therewith. The swage actuating drive element, which may also form part of a drive shaft connected to the mandrel, may co-act with the swage element or elements by mutual abutting engagement through conical or tapering surfaces during relative axial displacement.

It may, for example, comprise a shaft portion having a conical or tapering profile which is adapted to be displaced axially relative to a swage element or elements provided by a co-axial radially expandable tubular member, for example a springloaded split collet, or by radially displaceable balls or plungers located in a cage or carrier which may conveniently be formed by a co-axial tubular body integral with the mandrel. Such balls or plungers, associated with suitable spring bias means, may also form holding means for frictionally engaging the insert and retaining it in place when initially fitted on the mandrel where the latter is of plain cylindrical profile.Or, in another arrangement, the swage actuating drive element may form part of an axially movable drive shaft adapted to act through a thrust bearing surface against an internal conical or tapering surface of a co-axial radially expandible tubular member, again for example a spring-loaded split collet, providing the swage element or elements.

In some embodiments, the swage element or elements may also provide or be integrally formed with the insert axial limit stop and/or with stop surface portions adapted to engage the workpiece surface when the insert is fully screwed home.

Also. in some embodiments, especially where axial pressure for operating the swage means is produced or generated by an applied rotary input drive, the swage element or elements may be connected to the swaging drive input member so as to rotate during the swaging drive operation, thereby to carry out the swaging or expansion of the annular wall portion of the insert counterbore with a rolling action which may sometimes be advantageous in, for example, promoting metal flow.

By way of further example of the manner in which the invention may be carried out and in illustration of various features referred to above, several forms of tool representing different practical embodiments are shown in the accompanying drawings.

In said drawings, Figure I is a part-sectional elevational view showing a typical thin-walled screwthreaded insert of the kind which can be fitted and secured in place by the tools of the present invention, in association with a workpiece member; Figure 2 is a part-sectional elevational view of a tool according to a first embodiment:: Figure 3 is a similar view of a tool according to a second embodiment; Figure 4 is a cross-sectional view on line IV - IV of figure 3; Figure 5 is a view in longitudinal section of a tool according to a further embodiment; Figure 6 is a cross-sectional view on line VI - VI of Figure 5; Figure 7 is a view similar to Figure 5 showing another embodiment; Figure 8 is a longitudinal sectional view of another embodiment; Figure 9 is a fragmentary plan view of a portion of the tool shown in Figure 8; Figure 10 is a part-sectional elevational view of another embodiment; Figure lOa is a fragmentary portion of a view similar to Figure 10 but showing a first modification in the structure of the tool; Figure 11 is a fragmentary detail view in elevation of part of the tool of Figure 10; Figure 12 is a cross-sectional view on line XII - XII of Figure 10;; Figure 11a and 12a are views similar to Figures 11 and 12 but showing another modification in the structure of the tool; Figure 13 is a part-sectional elevation showing another embodiment: Figure 14 is a view mainly in longitudinal section of another embodiment; Figure 15 is a similar view of another embodiment: Figure 16 is a similar view of a yet further embodiment. the tool being shown in a condition immediately before carrying out a final swaging operation: Figure 17 is a fragmentary view showing a portion of the tool of Figure l6 immediately after carrying out the final swaging operation: Figure 18 is a longitudinal sectional view showing another embodiment; Figure 19 is a similar view of another embodiment. shown immediately after completing a final swaging opration:: Figure 20 is a fragmentary view showing a portion of the tool of Figure 19 immediately before the final swaging operation; and Figure 21 is a view. with part broken away, showing yet another embodiment.

Referring first to Figure 1. it will be seen that the typical thin-walled screw-threaded insert illustrated therein, which is denoted generally by reference I 10. comprises a cylindrical tubular body 11 having internal and external screw threads 12. 13. and a plain internal counterbore 15 adjacent one end. The counterbore 15 terminates in a chamfered internal shoulder 16 and defines a relatively thin annular wall portion 18 upon which the external thread form is knurled or otherwise serrated to provide a series of sharp external teeth or serrations 20.These are the teeth or serrations which, after screwing the insert into a prepared screw-threaded bore 22 in a workpiece member 23 (shown partially in Figure 1) so as to lie just below the outer surface 24, are caused to penetrate into the surrounding material of the workpiece by forcibly expanding the annular wall portion 18 radially outwards, thus to lock and secure the insert in place.

Such inserts may be produced in a variety of different sizes, and may be composed of mild steel or other suitable ductile metal or alloy depending on the size, conditions of use and physical characteristics of the workpiece material. Usually, however, the wall thickness will not exceed 1 mm.

Throughout the various Figures, the same reference numerals are used to denote the inserts and workpieces, and portions thereof, although in many cases, for convenience, these are illustrated in a very diagrammatic manner.

The tool of the first embodiment shown in Figure 2 may be used as an attachment to a hand-operated or power-operated rotary driving implement providing forward and reverse rotary drive, although it could also be engaged with an appropriate spanner or lever handle for example for use directly as a hand tool. It has a generally cylindrical form with different parts in co-axial relationship and comprises a relatively large diameter drive input member 31 integral with a drive shaft 32 having a reduced diameter forward portion 33 constituting a swage element which is in turn integrally connected to a cylindrical mandrel 34 having a screw thread 35 and terminating in a short plain pilot portion 36.The swage element 33 has a cylindrical profile of a diameter slightly greater than the internal diameter of the counterbore 15 of the insert 10 and terminates in a curved cam form swaging surface portion 37. As shown, this cam form portion has a convex curvature, but it could alternatively have a concave curvature.

Telescopically mounted on the main portion of the drive shaft 32 for axially sliding movement is a tubular member or sleeve 38 spring-loaded by a compression spring 39 and located by a radially projecting retaining pin 40 fixed to the drive shaft. This pin 40 engages in an axially elongate slot 42 in the sleeve 38, thereby preventing relative rotation and controlling the extent of relative axial movement. The sleeve 38 provides an axial limit stop for the insert by virtue of its end face 44 which forms a stop surface.

In use, the insert 10 is screwed on to the mandrel 34 until its end adjacent the counterbore 15 engages the end face 44 of the stop sleeve 38 without compressing the spring 39. The insert thus mounted on the mandrel and held in palce by the screw thread 35 is then presented to the bore 22 of the workpiece 23 and a clockwise rotary drive is applied to the tool through the drive input member 31. This rotates the mandrel 34 and causes the insert to screw into the bore 22 under an axial pressure applied through the end face 44 of the stop sleeve 38 until the radially outermost portion of this end face 44, which projects laterally beyond the end of the insert, contacts the workpiece surface 24. At this stage, the insert 10 is screwed fully home and further feed ceases.

Upon continuing to apply the rotary input drive, in a continuous process, the mandrel then screws axially into the insert and the stop sleeve 38 retracts on the drive shaft 32, compressing the spring 39. Finally, the swage element 33 is forcibly drawn into the counterbore 15 and, in so doing, the cam form swaging surface portion 37. whilst rotating, bears against the wall portion 18 to expand it radially outwards with a rolling action thereby to lock and secure the insert in place as previously described.

After completing this swaging operation, the tool is removed by applying an anticlockwise rotarv drive motion to the input member 31 which unscrews the mandrel 34 from the insert enabling the stop sleeve 38 to return to its initial position and leaving the tool ready for use again without need for any resetting or adjustment.

The next tool illustrated, in Figures 3 and 4. is a hand tool comprising a drive shaft 50 having a drive input handle portion 51, fitted with a tommy bar 52. towards one end and having a conically tapered swage actuating portion 54 towards the other end integral with a screw threaded cylindrical mandrel 56 terminating in a reduced diameter plain pilot portion 57. Fitted around the tapered portion 54 is a split collet 59 of which separate halves or segments 59a, 59b, are resiliently held together by retaining spring circlips 60 and form swaging elements providing swaging surfaces on a nose portion 61 which can fit into the insert counterbore 15.The collet 59 also provides an axial limit stop for the insert by virtue of a stop surface formed by end face portions 62 of the collet segments being adapted to abut against the end of the insert and also to engage the workpiece surface 24 when the insert is fully screwed home.

In use. the insert 10 is screwed on to the mandrel 56 so as to engage the axial limit stop provided by the collet 59. Then. whilst thus mounted on the mandrel and held in place by the screw thread, the insert is presented to the workpiece bore 22 and is screwed home therein, under axial pressure through the collet 59. by applying a clockwise rotary drive through the tommy bar 52 and handle portion 51. When the insert is fully home, the radially outermost part of the stop end face portions 62 engage the workpiece surface 24 so preventing further axial movement of the collet, but the rotary drive input is maintained to cause the mandrel then to screw into the insert.This causes the drive shaft 50 to move axially and the tapered portion 54 is drawn through the collet causing the segments 54a, 54b, providing the swage elements, to be spread apart and expand radially so that the nose portion 61 within the counterbore expands the counterbore wall portion 18 as required for the swaging operation. During this swaging operation, the collet 59 will continue to rotate with the drive shaft 50 through frictional engagement therewith so that again the swaging takes place with a rolling action. Finally, to remove the tool, it is simply turned in an anti-clockwise direction to unscrew the mandrel from the insert and it is then ready for use again.

If desired, instead of being split into two halves the collet 59 may alternatively be in the form of a one-piece tubular body having an appropriate longitudinal slot or slots to provide for the required radial expansion thereof.

The tool of Figures 3 and 4 can also be designed in a slightly modified form as an attachment for use with a rotary power driving implement such as a power operated drill. In this case, the drive shaft may have a one piece tubular body and a suitable clutch unit should be incorporated.

The tool of Figures 5 and 6 is, in the form illustrated, also a hand tool. It comprises a stepped diameter central drive shaft 70 integral with a nose portion 71 and a screw-threaded mandrel 72 terminating in a pilot portion 73. It also includes a tubular body 74 forming the drive input member for screwing home the insert, and clutch means, including two clutch rollers 76. 76, housed in specially shaped restrictive clutch apertures or recesses 77, 77, for uni-directional transmission of rotary drive between the body 74 and drive shaft 70. The body 74. which has a knurled surface 79, has an integral reduced diameter forward portion 80 providing an axial limit stop with an end stop surface 81 for engaging the end of the insert 10 and also the workpiece surface 24. The larger diameter section of the drive shaft 70 terminates at the rear in a handle portion 83 provided with a tommy bar 84 for input of a rotary swaging drive and it is accommodated within the body 74 in a bore 85 which terminates in an internal shoulder 86 positioned so as to permit limited axial movement of the drive shaft 70. A screw cap 88 retains the clutch rollers 76. 76. in place.

The nose portion 71 constitutes a swage element and provides an annular cam form swaging surface 89.

In use. with the drive shaft 70 and body 74 set initially in the relative axial relationship shown in Figure 5. the insert 10 is screwed on the mandrel 72 until it abuts the surface 81 of the axial limit stop portion 80, and thus mounted it is presented to the bore 22 of the workpiece 23. A clockwise rotary drive input for screwing the insert home is then applied by hand to the body 74 which can be gripped around its peripheral knurled surface 79. As will be clear by referring to Figure 6, this causes the clutch rollers 76, 76, to move towards the narrower ends of their clutch recesses 77, 77, so that they jam (as shown in full lines in Figure 6) and transmit the rotary drive frictionally to the central drive shaft 70.The insert 10 is screwed into position, under axial pressure applied through the axial limit stop portion 80, until the radially outermost portion of the stop surface 81 contacts the workpiece surface 24 which prevents further axial movement and feed. At this stage, the body 74 is then held stationary and for securing the insert in place a clockwise rotary swaging drive is applied directly to the drive shaft 70 through the tommy bar 84 and handle portion 83. This produces a reversal in the direction of relative rotation between the drive shaft 70 and body 74 so that the clutch rollers 76, 76, move towards the larger ends of the clutch recesses 77, 77, (as shown in broken lines in Figure 6) and automatically disengage the rotational drive coupling between these parts.The mandrel 72 therefore screws forwards into the insert, moving the drive shaft 70 axially and causing the swage element nose portion 71 to enter the counterbore 15 and expand the annular wall portion thereof by thrust from the cam form swaging surface 89. as with the previous embodiments.

After completing the swaging operation the tool is disengaged by an anti-clockwise rotation applied to the tommy bar 84 which unscrews the mandrel. but before being used again the tool must be reset to bring the drive shaft 70 and body 74 back to their initial relative axial positions in which the swage element nose portion 71 is retracted just inside the axial limit stop portion 80.

This tool of Figures 5 and 6 could also be slightly modified. if desired, so as to be in the form of an attachment for a power operated or hand operated rotary driving implement for supplying at least the rotary swaging drive to the rear end of the drive shaft 70.

The tool shown in Figure 7 may be regarded as a variant of the previous embodiment and again comprises a main drive shaft 90 passing coaxially through an outer tubular body 91 and integral at the forward end with a swage element nose portion 92 and a screw threaded mandrel 93 terminating in a pilot portion 94. At the rear. the drive shaft 90 terminates in a handle portion provided by a knob 96 having a knurled surface 97. The tubular body 91 is fitted with a tommy bar 98 for applying a rotary drive to screw home the insert, and again it has an integral reduced diameter forward portion 100 providing an axial limit stop with an end stop surface 101 for engaging the end of the insert 10 and also the work-piece surface 24.

Also, the swage element nose portion 92 again provides an annular cam form swaging surface 102.

As shown, the drive shaft 90 has an enlarged screw-threaded portion 104, of larger diameter than the forward end, which engages within a screw-threaded bore portion 105 of the body 91 towards the rear of which is a radial stop screw 106. The stop screw 106 projects into a space 107 formed by a short reduced diameter section of the drive shaft immediately behind the screwthreaded section 104.

In use, initially the tool is set as shown.

The insert 10 is then screwed onto the mandrel 93 until it abuts the surface 101 of the axial limit stop portion 100, and it is then presented to the bore 22 of the workpiece 23. A clockwise rotary drive input for screwing the insert home is then applied by hand to the body 91 through the tommy bar 98 and this is communicated to the drive shaft 90 through the screw-threaded portion 104 backed by the stop screw 106. Thus, the insert 10 is screwed into position, again under axial pressure applied through the axial limit stop portion 100, until the radially outermost portion of the stop surface 101 contacts the workpiece surface 24 which prevents further axial movement and feed.

At this stage, as with the previous embodiment, the body 91 is then held stationary and for securing the insert in place a clockwise rotary swaging drive is applied directly to the drive shaft 90 through the handle knob 96, the screw-threaded bore portion 105 enabling the drive shaft to move forward axially relative to the body 91 under these conditions. Thus, the mandrel 93 also screws forwards in the insert, causing the swage element nose portion 92 to enter the counterbore 15 and expand the annular wall portion thereof by engagement of the swaging surface 102. Relative axial movement of the drive shaft within the body 91 is limited in both directions by the stop screw 106 within the space 107.

After completing the swaging operation, the tool is again disengaged by an anticlockwise rotation applied to the swaging drive knob 96 which unscrews the mandrel, and before further use the tool is reset to being the drive shaft 90 and body part 91 back to the same relative axial positions shown in Figure 7.

The tool shown in Figures 8 and 9 is designed to be used as an attachment to a power operated or hand operated rotary drive implement which constitutes an exter nal rotary drive source, and it includes mechanically operated telescopically sliding swage means. The tool comprises an adaptor member 110 for fixing to the body of the rotary drive implement which has a main rotary drive shaft 111. The adaptor 110 carries a telescopically slidable assembly comprising a forwardly extending tubular body 112 and a swage element 118. The tubular body 112 is mounted on a nose portion of the adaptor member 110 for telescopic sliding movement which is limited by stop screws 114 biased by springs 115 housed in recesses in said nose portion of the adaptor member 110.The forward end of the body 112 has an internally screwthreaded bore 116 to which is fitted pluglike swage element 118 held in adjusted axial position by a lock-nut 119. The swage element 118 has a nose portion which provides the cam form annular swaging surface 120 and passing centrally therethrough is an auxiliary driving shaft 122 which is adjustably fixed to the main drive shaft 111 by a threaded portion 124 and a locking set screw 125 accessible through an opening 126 in the tubular body 112. This auxiliarv driving shaft 122 is formed integral at its forward end with a screw-threaded mandrel 128 terminating in pilot portion 129 and has an integral collar 130 adjacent the mandrel 128. The collar 130 forms an axial limit stop for the insert.

The adaptor member 110 also forms a mounting for the pivot 132 of a lever 133 having forked end portions or side arms 134 carrying inwardly directed actuating pins 135 which engage the rear end face of the tubular body 112 (see Figure 9). The main operating arm 136 of the lever 133 (not shown in full) extends rearwardly so as to lie at a small angle in spaced relationship with the body of the rotary drive implement.

In operation, the insert 10 is screwed on to the mandrel 128 until it engages the axial limit stop formed by the collar 130 which enters the counter bore and abuts against the internal chamfered shoulder therein.

The insert, mounted on the mandrel, is then presented to the workpiece bore and is screwed home therein by applying a rotary drive from the drive shaft 111 through the auxiliary driving shaft 1'2, an axial driving pressure being supplied through the stop collar 130. After the insert has been screwed in to the desired extent. which the operator will judge by eye. the rotary drive is stopped and the lever 133 is operated to cause the tubular body 112 to be thrust forward with relative sliding movement, thereby causing the nose portion of the swage element 118, with the swaging surface 120, to enter into the counterbore of the insert and expand the annular wall portion thereof as in the other embodiments.After completing this swaging operation, the handle 136 of the lever 133 is released and the tubular body 112 slides back automatically under the action of the springs 115 thereby withdrawing the swage element 118, and an anti-clockwise rotation is applied to the drive shaft to unscrew and remove the mandrel 128 from the insert.

With the structure illustrated, the depth of penetration of the nose portion of the swage element 118 into the counterbore of the insert 10 can be controlled by adjusting the axial position of the element 118 in or out of the body 112 after slackening the lock-nut 119. With this tool, it will be appreciated that the swage element 118 does not rotate during the swaging operation, and the engagement of the screw thread of the mandrel 128 with the insert serves to hold the drive shaft stationary whilst the swage element slides relative thereto.

The next tool, illustrated in Figures 10 to 12, has an even more versatile construction.

This tool comprises a central spindle or drive shaft 140 of which the rear section has a screw thread 141 whilst the forward section, at its front end, provides an intergral screw threaded mandrel 142 adjacent to an integral annular stop collar 144. The drive shaft 140 is partially housed over its forward section in a larger diameter tubular body 145 to which it is connected by a screw-threaded internal plug cap 146 held in adjusted position upon the screw thread 141 by a lock nut 148. The plug cap 146 is non-adjustably secured to the body 145 by set screws (not shown) engaging in radial tapped holes 149.Below these set screws, the holes 149 also contain brass pads (not shown) which are pressed radially inwards to bear against the drive shaft 140, thereby to provide additional frictional restraint to prevent any loss of adjustment or setting between the drive shaft 140 and body 145.

Surrounding the rearmost portion of the body 145 and part of the rear section of the drive shaft is a stepped diameter rotatable outer sleeve 150 of which the rear end abuts against an axial locating stop provided by a locknut 152 on the drive shaft. The larger diameter front portion of the outer sleeve 150, which surrounds the rearmost portion of the body 145. has a front end face 154 of helical cam form defining a pair of diametrically aligned detent recesses which can each be regarded as having a substantially semicircular profile providing an arcuate seating surface portion 156 cut back at one side to provide an adjacent helical cam surface portion 157 leading up to the crest of the cam form.

Within the tubular body 145 and coaxially surrounding the forward section of the drive shaft 140 there is housed an elongate tubular swage element 159 which is mounted for telescopic axial sliding movement. The swage element 159 is spring loaded by a compression spring 160 which acts between an annular face of a relatively enlarged head portion 162 at the rear end and an internal annular shoulder 164 within the bore 165 of the body 145 which is of reduced diameter at the front end.The head portion 162 of the swage element 159 carries a cross-pin 167 which fits in a transversely extending cylindrical hole so that the opposite end portions of the cross-pin 167 project through axially elongate slots 168 in the tubular bodv 145 and engage the helical cam form front end face 154 of the outer sleeve 15(). The cross-pin 167 itself has a central transverse hole or aperture 170 which accommodates the central drive shaft 140.

In the normal condition of the tool the outer end portions of the cross-pin bear against the arcuate seating surface portions 156 of the cam end face 154, as shown most clearly in Figures 10 and 11. under a rearwardly directed pressure from the bias spring 160 so that the outer sleeve 150 is kept pressed against the locknut locating stop 152.

At the front end. the swage element 159 has a curved cam profile nose 172, providing an annular swaeing surface. which lies retracted within the bore of the body 145 whilst the swage element is held back by the spring 16().

In use. as with previous embodiments. the insert l() is screwed on to the mandrel 142 until its internal shoulder 16 in the counterbore ln engages the collar 144 which forms an axial limit stop. The insert, mounted on the mandrel, is then presented to the screw threaded bore 22 of the workpiece 23 and a clockwise rotary drive is applied to the outer sleeve 150 either manually, by fitting a handle or tommy bar for example, or by fixing the sleeve 15() in the chuck of a rotary driving implement such as. for example. a power operated drill equipped with forward and reverse drive.The rotary drive is transmitted through the recessed cam form end face 154 and cross-pin 167 to the body 145, swage element 159 and drive shaft 140 so that all the complements of the tool revolve together, and the insert l() screws home into the workpiece bore 22. This continues until the front end face 174 of the body 145, forming an outer stop surface, contacts the surface 24 of the workpiece which prevents further axial feed movement. Then. upon continuing to turn the outer sleeve 150. cam action through the end face 154 causes the cross-pin 167 to be forced forwards, against the bias of the spring 160. and to ride up the helical cam surface portions 157 to the crest of the cam form.As a result. the swage element 159 is forced forwards so that the nose 172 enters into the insert counterbore 15 and expands and flares out the annular wall portion thereof to fix the insert in place.

Finally, further continued rotation of the outer sleeve 150 beings the detent recesses into registry again with the cross-pin 167 which moves back again to re-enter these recesses and bear against the arcuate seating surface portions 156, causing the swage element 159 to retract, under the action of the compression spring 160. The process of the cross-pin riding up to the crest of the cam form and then falling back into the detent recesses, and reciprocation of the swage element 159, will continue repetitively if the rotary drive to the outer sleeve 150 is maintained, giving rise to a series of readilv audible clicks which will indicate to the operator that the swaging operation has been completed.The rotary drive can then be reversed whereupon the deeper sides of the detent recesses bear against the crosspin 167 and all the components of the tool again rotate together as a unit in an anticlockwise direction, thereby unscrewing the mandrel 142 from the insert 10 and freeing the tool which will be ready for immediate re-use without need for any resetting operation. Thus, the whole operation is carried out by successive simple right-hand and left-hand revolution of the tool without need for any intermediate interruption or pause.

The insert 10 will generally be required to be screwed into the workpiece bore 22 until its end is flush with. or slightly below, the workpiece surface 24. But, the exact depth to which the insert is set in the workpiece bore 22 is autdmatically determined, with this tool, by the position of the axial limit stop collar 144 relative to the outer stop surface 174, and this is pre-set by the locknut 148 and threaded plug cap 146 fixing the body 145 to the drive shaft 140. By slackening the locknut 148 and screwing the body 145 and plug cap 146 along the screw thread 141, this setting can be varied in a preliminary adjustment operation to suit requirements.

Also, the depth to which the swage element 159 penetrates into the insert counterbore depends on the initial position of the swage element relative to the front end of the body 145 and is controlled by the axial position of the locknut 152 on the shaft 140.

Again. the position of this locknut 152 can be varied in a preliminary adjustment operation to pre-set the depth of swaging to the value required.

This form of tool, with these independent adjustment means and automatic control of the setting depth of the insert and depth of swaging, is therefore well adapted for reliable and consistent operation and requires little or no particular skill by the operator.

In one modification of the tool of Figures 10 to 12, as shown in Figure 10a the swage element 159 may be formed by two unconnected separate parts, a rear part 159a which includes the head portion 162 and which is spring loaded by the compresion spring 160, and a front part 159b which includes the nose 172. As will be clear from Figure 10a, the front part 159b floats on the drive shaft 140 within the reduced diameter section of the bore 165 of the body 145, and before the insert is screwed on to the threaded mandrel 142 it will rest against and is retained bv the collar 144. When the insert 10 is screwed into place on the mandrel it will push the part 159b up the drive shaft 140, and during swaging the tool operates as already described.The separation of the swage element into two parts in this manner is, however, advantageous in that if the nose 172 should jam in the counterbore of the insert during swaging, the rear part 159a is still able to retract to permit the cross pin 167 to re-engage with the recessed profile of the outer sleeve 150 as is necessary for unscrewing the mandrel and freeing the tool upon reversing the rotary drive after completion of the swaging operation.

In another modification of the tool of Figures tO to 12, illustrated in Figures 11a and 12a. the outer sleeve 150 has a front end face 154a of modified helical cam form defining a single detent recess with an arcuate seating surface portion 156a and an adjacent helical cam surface portion 157a which now extends around the major part of the circumference of the end face. Also, to accommodate this modified cam form. the cross-pin. now shown by the reference 167a.

is shortened so that it only projects radially from one side of the body 145. The greater length and shallower incline of the cam surface portion 157a in this modification is advantageous in that less torque is required for displacing the swage element. but otherwise the tool operates as before.

The embodiment of Figure 13 is a simple hand tool suitable for light work. It comprises a drive shaft 18() having a handle portion 181 at one end and. at the other end, an integral stop coller 182 and screw-threaded mandrel 184 terminating in a plain cylindrical pilot portion 185. A swage element in the form of a weighted or heavy sleeve member 186 having a nose portion with a curved cam form annular swaging surface 187 is slidably mounted on the drive shaft 1XO. and a compression spring 188 is fitted between the swage element 186 and the handle portion 181.

In use, again the insert 10 is screwed on to the mandrel 184, up to the axial limit stop formed bv the collar 182, and is presented to the workpiece bore. The insert is then screwed home, by manually rotating the handle portion 181, until it is judged to be flush with the workpiece surface. The swage element 186 is then pulled back by hand, compressing the spring 188 as shown in Figure 13, and is then released so as to be projected or impelled towards the insert.

Thus. the insert is struck by the nose portion of the swage element 186 which enters the counterbore 15 causing the cam form annular swaging surface 187 to engage and expand the annular wall portion thereof.

And finally, the handle portion 181 is turned in an anti-clockwise direction to unscrew the mandrel from the insert and thereby remove the tool which is ready for immediate re-use without need for re-setting or adjusting.

The next embodiment, illustrated in Figure 14, is an example of a simple hand tool, in accordance with the invention which is designed for operation with an impact or percussive axial swaging drive. The tool comprises a cylindrical drive shaft 190 fitted with a tommy bar 191 adjacent its outer rearmost end and provided at its opposite end with an integral screw-threaded mandrel 192 terminating in a plain pilot portion 193. Mounted on the drive shaft 190 for telescopic sliding movement is a tubular swage element 195 having a striker head or cap 196 projecting beyond the outer rearmost end of the drive shaft. A slot 197 accommodates the tommy bar 191 and permits limited relative axial displacement.

The swage element 195 has a forward section 198 of reduced diameter terminating in a nose providing a curved cam form annular swaging surface 199. Surrounding the swage element 195 is an outer tube 200 of which the front portion provides a flat end face 202 and houses a compression spring 203 which normally keeps the swage element 195 retracted. The tommy bar 191 passes through, and fits closely in, diametrically aligned holes of the outer tube 200 which is thereby effectively secured to the drive shaft 190.

In use, the insert 10 is screwed on to the mandrel until its end engages the flat end face 202 of the outer tube 200 which forms an axial limit stop. The insert is then presented to the workpiece bore 22 and is screwed home therein, by applying a clockwise rotary drive to the drive shaft 190 using the tommy bar 191. until the radially outermost position of the stop end face 202, which extends laterally beyond the end of the insert, contacts the workpiece surface 24. The striker head or cap 196 is then struck, as by a sharp blow from a hammer, to drive the swage element 195 forwards, compressing the spring 203 and causing the nose with the swaging surface 199 to enter the insert counterbore and perform the swaging operation.The spring 203 then automatically retracts the swage element and an anti-clockwise drive is applied to the tommy bar 191 to unscrew the mandrel so as to extract the tool which is then ready for immediate re-use.

The tool which is shown in Figure 15 acts in a somewhat similar manner to that of the last embodiment and may be regarded as a variant thereof in which the external stop tube is not used. In this case, the tool has a central drive shaft 210 which has an integral stop collar 211 and screw-threaded mandrel 212 at one end. and a relatively enlarged diameter section 214. defining a shoulder 215. at the other end. This drive shaft 210 is slidably fitted within an outer tube 216 which constitutes the swage element. these two components being connected to rotate together bv a cross-pin 218 that passes through a slot 219 in the drive shaft section 214 permitting a limited extent of relative axial displacement.The tubular swage element 216 is fitted with a tommy bar 220 for manually applying a rotary input drive to the tool. and the drive shaft 2)0 is spring loaded by a compression spring 222 confined between its rear end face in the bore 224 of the tubular swage element and the tommy bar 22().

The forward end or nose of the tubular swage element 216 is again formed at 225 with a curved cam form annular swaging surface adapted to enter the insert counterbore 15 to flare out and expand or swage the annular wall portion 18 thereof.

In use. after fitting the insert 10 on the mandrel 212 as before. with the collar 211 forming an axial limit stop engaging the internal chamfered shoulder within the counterbore, the insert is applied to the workpiece bore 22 and is screwed home by a clockwise rotary drive input applied by the tommy bar 220 to the swage element 216 which transmits this drive to the drive shaft 21() through the cross-pin 218. After screwing home. the rear end face 227 of the swage element 216 is struck with a hammer to provide an axial impact or percussive force, driving the swage element forward against the spring 222 to carry out the swaging operation.The spring 222 then returns the components to their initial relative positions and the tool is withdrawn by turning the tommy bar 22(1 to unscrew the mandrel 21' from the insert.

A somewhat different form of tool is illustrated in Figures 16 and 17. This is designed for use with a hand or power operated rotary driving implement providing forward and reverse drive. line tool has a nitin drive shaft 73(). adapted at its rear end (not shown) for coupling to the rotary drive output member of the driving implement. with a reduced diameter forward section 231 upon which is mounted a tubular driving member 233 retained in place by a headed set screw 234. The forward end of the driving member 233 forms a cylindrical screw-threaded mandrel 235, and there is an outer tubular housing or sleeve body 236 which surrounds part of the larger diameter section 237 of the drive shaft and the rear portion of the driving member 233.The housing 236 has an internal annular rib 238 which defines two interior spaces 240. 241, accommodating substantially equal compression springs 242, 243.

At the front end, the sleeve body 236 is fitted with a swage element 245 which is screwed into place. The swage element 245 has a radial flange 246 having a slightly sloping front face 247 and has a nose portion 248 providing a curved cam form swaging shurface 249. The nose portion 248 with the surface 249 also forms an axial limit stop when the insert is initially screwed into place on the mandrel. The sleeve body 236 is further provided with radial bores 251 which house hardened steel balls 252 biassed inwards by springs 253 retained in place by screw-threaded closure caps 254. These steel balls 252 are arranged to engage complementary detent recesses 255 in the surface of the drive member 233 to locate and retain the driving member 233 and sleeve body 236 normally in the relative axial positions shown in Figure 16.

In operation, the insert 10 is screwed on to the mandrel 235 until its end engages the surface 249 of the nose portion 248 which at this stage acts as an axial limit stop. as shown in Figure 16. Upon then presenting the insert to the workpiece bore 22 and applying a clockwise rotary drive to the drive shaft 230, all the components of the tool turn together since the driving member 233 with integral mandrel 235, housing 236, and drive shaft 230 are effectively operative ly interconnected for transmission of this rotary drive by spring-loaded friction coupling means. Therebv. the insert is screwed home until it lies substantially flush with the workpiece surface 24.The rotary drive is then discontinued and the rotary drive implement is pushed forwards to applv an axial pressure to the drive shaft '3(i for carrying out the swaging operation. The drive shaft slides forwards relative to the driving member 233. compressing the rearmost spring 243 and thus also applying an axial pressure to the sleeve body 236.As this pressure increases. ultimatelv the resistance of the spring-londed balls 252 is overcome and thev are forced out of engagement with the recesses 255 so that the sleeve body 236, carrying the swage element 248. is forcibly projected forwards, forcing the nose portion 248 into the counterbore 15 and expanding the annular wall portion by the pressure through the cam form swaging surface 249. as indicated in Figure 17. The depth of penetration into the counterbore may be limited by engagement of the face 247 of the flange 246 with the workpiece surface 24.

All the tools so far described have included a screw-threaded mandrel for mounting and holding the insert, but in some embodiments a plain cylindrical mandrel may be provided for mounting and locating the insert, in conjunction usually with resilient frictional holding means.

Thus, in the embodiment illustrated in Figure 18, the tool has a main drive shaft 260 which can be coupled to a hand or power operated rotary driving implement for supplying a clockwise rotary drive and which has a cylindrical head portion 261 of relatively enlarged diameter terminating in a conically tapering protrusion 262.

Mounted on the drive shaft 260 for relative telescopic sliding movement is a tubular sleeve body 264 forming a housing for a compression spring 265 which is retained in place behind the head portion 261 of the drive shaft by a screw cap 266. The forward portion of the sleeve body 264 forms a plain cylindrical mandrel 268 of reduced diameter adapted to fit closely within the screw threaded bore of an insert 10. and it terminates in a short front pilot portion 269.

Intermediate its length, the sleeve body 264 also has a radially protruding annular enlargement 270 with an inclined front face 272, forming a stop surface, adjacent a number of holes 273 through the body wall which accommodate. and are profiled to provide a seating for. a corresponding number of internal steel balls 275 arranged to project partially through the body wall. In Figure 18. two holes 273 and two balls 275 are shown but it will be understood that a larger number may be provided, if desired, in circumferentially spaced relationship. As shown, within the bore 277 of the sleeve body 264. the balls 275 lie against the conical surface of the protrusion 262, and are normally urged radially outwards by the bias effect of the spring 265.

In use. the insert 10 is mounted on the mandrel 268 by being simply pushed into place until it contacts the stop surface 272, the annular wall portion 18 of the counterbore 15 riding over the balls 275 which are pushed inwards. The insert is then held in position bv the radial outwards pressure exerted by the balls 275 and can be carried and presented to the workpiece bore 22.

Then. a clockwise rotary drive is applied through the drive shaft 260 which is transmitted frictionally to the sleeve body 264 and to the insert so that the latter screws home into the bore 22 whilst a light axial feed pressure on the tool is applied to the insert through the stop surface 272. This continues until the radially outermost portion of the stop surface 272 engages the workpiece surface so that further axial feed movement ceases. At this stage, whilst the rotary drive is maintained, a strong forwards pressure, from the rotary driving implement, is exerted on the drive shaft 260 by the tool operator, forcing the balls 275 outwards under a strong radial pressure by the wedge action of the conically tapering protrusion 262 which can be sufficient to carry out the swaging operation which is performed with a rolling action by the balls 275 which act as swage elements.

On completion of this swaging operation, the tool is simply pulled away and withdrawn from the insert and is ready for immediate re-use.

Another variation of this general form of tool is shown in Figures 19 and 20. This has a main drive shaft 280 which again is intended to be coupled to a drive output member of a hand or power operated rotary driving implement. The drive shaft 280 terminates at the front in a conical tapering protrusion 281 and it carries an outer sleeve body 282 mounted for telescopic relative sliding movement under the control of two substantially equal compression springs 284, 285, which are housed in an enlarged bore portion 286 either side of a partitioning collar 287 integral with the drive shaft. The springs are retained in place by a closure cap or plug 289 which closes the rear end of the bore portion 286.

The outer sleeve body 282 is formed towards the front with a radially protruding flange 290 having a slightly inclined front stop face 291, and forwardly of this the diameter of the sleeve body decreases over a short tapering section 293 to terminate in a plain cylindrical mandrel 295 and pilot portion 296 integral therewith. A number of circumferentially spaced holes 298 with internal counterbores 299 in this tapering section 293 accommodate a corresponding number of short headed plungers 300 which constitute swage elements. The stem portions 301 of these plungers 300 project, at a slight angle to a radial plane, through these holes 298 and terminate in a rounded swaging surface 305. Within the bore 304, the head portions 302 bear. through a convex end face 303, against the conically tapering protrusion 281 of the drive shaft.

In use, the insert 10 is again first mounted on the mandrel by being pushed into place until its end abuts the innermost portion of the stop face 291, which forms an axial limit stop as shown in Figure 20. At this stage, the drive shaft is retracted slightly against the spring 285 so that the plungers 300 move inwards to permit the annular wall portion 18 of the insert to pass over. When the insert is in place, however. the plungers press against this annular wall portion, as a result of the spring bias and wedge action of the tapering protrusion 281. so as to exert a frictional holding pressure retaining it in position.The insert is then applied to the workpiece bore 22 and is screwed home by rotary drive applied to the drive shaft and all the components of the tool rotate together with the drive being transmitted frictionally to the insert until the outermost portion of the stop face 291 engages the workpiece surface 24. The axial feed then ceases and the tool operator applies a strong axial thrust which causes the pluhgers 300, acting as swage elements, to press strongly against the counterbore wall portion and, again, to carry out the swaging operating with a rolling action as indicated, with some exaggeration, in Figure 19. When the swaging operation is completed, again the tool can be simply pulled away and withdrawn ready for immediate re-use.

In the final embodiment shown in Figure 21, the tool has a main drive shaft 310 formed with a truncated conical section 311, an integral stem portion 309 of reduced diameter, and an integral plain cylindrical mandrel 312 and front pilot portion 308.

The truncated conical section 311 is fitted with a radially expandible collet 313 of which the body part is held resiliently contracted by a spring retaining ring 314. To provide for the radial expression. as described for the collet 59 of the embodiment of Figures 3 and 4. the collet 313 may be split into two halves or it may be a one-piece tubular body formed with an appropriate longitudinal slot or slots.

As shown, the collet 313 has a radially protruding flange 315 with a front stop surface 316 leading on to an inwardly tapering front conical portion 318 which provides an internal space 319 housing a number of bearing balls 320 immediately in front of the conical section 311 of the drive shaft.

In use, the insert 1() is pushed on the mandrel 312 until its end contacts the innermost portion of the stop surface 316 or conical portion 318 forming the axial limit stop. The insert is then presented to the workpiece bore 22 and is screwed home by applying a clockwise drive to the drive shaft, together with a light axial feed pressure.

using a hand or power operated rotary driving implement. Then, when the outermost portion of stop surface 316 contacts the workpiece surface 24, the forward feed of the insert ceases. The rotary drive is maintained, however, and a stronger axial thrust is applied, causing the conical section 311 to act through its front face 324 and balls 320 to radially expand the body part of the collet 313, thereby to carry out the swaging operation again with a rotary rolling action and radial expansion. Then. when the swaging is completed, the tool can be simply withdrawn.

WHAT WE CLAIM IS: 1. A tool for use in the fitting and securing in place of thin-walled screwthreaded inserts, of the kind referred to, in complementary screw-threaded bores prepared in workpiece members, said tool comprising a plurality of separate component parts which are assembled together and which provide: an elongate mandrel designed to be introduced into and to fit and locate co-axially within the screw-threaded bore of a said insert; an axial limit stop arranged to engage in abutting relationship with the insert when the tool is in use and the mandrel is properly fitted and located within the bore of said insert; a drive input member, co-axial with said mandrel, for receiving a rotary input drive from an external rotary drive source when the tool is in use for fitting said insert in a said prepared bore in a said workpiece member; means effective to transmit such input drive from the drive input members to the insert so as to cause the insert to be rotated. while the mandrel is properly fitted and located as aforesaid within the screwthreaded bore thereof. and thereby to enable said insert to be screwed home in said prepared bore in said workpiece member under an axial pressure. also provided or derived from said input drive, applied through said axial limit stop; and swage means operable to perform a swaging operation, during use of the tool after said insert has been screwed home in said bore of the workpiece member, to effect forcible expansion of said annular wall portion of the insert counterbore radially outwards for locking and firmly securing the insert in place; at least two said component parts of the tool being displaceable relative to one another in the axial direction in order to bring about said operation of said swage means.

2. A tool as claimed in Claim 1, wherein the mandrel is provided with an external screw-thread for engaging the internal screw-threaded bore of the insert and is operatively connected through a drive shaft to the drive input member for the transmission of rotary input drive therebetween, wherein said axial limit stop is provided by a member in fixed spatial relationship with the mandrel, and wherein the swage means comprises a swage element mounted in the tool for axial sliding displacement and having a nose portion at its forward end providing a cam form annular swaging surface, said swage element being adapted to be projected or impelled axially into swaging impact engagement with the insert during use by an axial swaging drive force applied thereto.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. of the spring bias and wedge action of the tapering protrusion 281. so as to exert a frictional holding pressure retaining it in position. The insert is then applied to the workpiece bore 22 and is screwed home by rotary drive applied to the drive shaft and all the components of the tool rotate together with the drive being transmitted frictionally to the insert until the outermost portion of the stop face 291 engages the workpiece surface 24. The axial feed then ceases and the tool operator applies a strong axial thrust which causes the pluhgers 300, acting as swage elements, to press strongly against the counterbore wall portion and, again, to carry out the swaging operating with a rolling action as indicated, with some exaggeration, in Figure 19.When the swaging operation is completed, again the tool can be simply pulled away and withdrawn ready for immediate re-use. In the final embodiment shown in Figure 21, the tool has a main drive shaft 310 formed with a truncated conical section 311, an integral stem portion 309 of reduced diameter, and an integral plain cylindrical mandrel 312 and front pilot portion 308. The truncated conical section 311 is fitted with a radially expandible collet 313 of which the body part is held resiliently contracted by a spring retaining ring 314. To provide for the radial expression. as described for the collet 59 of the embodiment of Figures 3 and 4. the collet 313 may be split into two halves or it may be a one-piece tubular body formed with an appropriate longitudinal slot or slots. As shown, the collet 313 has a radially protruding flange 315 with a front stop surface 316 leading on to an inwardly tapering front conical portion 318 which provides an internal space 319 housing a number of bearing balls 320 immediately in front of the conical section 311 of the drive shaft. In use, the insert 1() is pushed on the mandrel 312 until its end contacts the innermost portion of the stop surface 316 or conical portion 318 forming the axial limit stop. The insert is then presented to the workpiece bore 22 and is screwed home by applying a clockwise drive to the drive shaft, together with a light axial feed pressure. using a hand or power operated rotary driving implement. Then, when the outermost portion of stop surface 316 contacts the workpiece surface 24, the forward feed of the insert ceases. The rotary drive is maintained, however, and a stronger axial thrust is applied, causing the conical section 311 to act through its front face 324 and balls 320 to radially expand the body part of the collet 313, thereby to carry out the swaging operation again with a rotary rolling action and radial expansion. Then. when the swaging is completed, the tool can be simply withdrawn. WHAT WE CLAIM IS:

1. A tool for use in the fitting and securing in place of thin-walled screwthreaded inserts, of the kind referred to, in complementary screw-threaded bores prepared in workpiece members, said tool comprising a plurality of separate component parts which are assembled together and which provide: an elongate mandrel designed to be introduced into and to fit and locate co-axially within the screw-threaded bore of a said insert; an axial limit stop arranged to engage in abutting relationship with the insert when the tool is in use and the mandrel is properly fitted and located within the bore of said insert; a drive input member, co-axial with said mandrel, for receiving a rotary input drive from an external rotary drive source when the tool is in use for fitting said insert in a said prepared bore in a said workpiece member; means effective to transmit such input drive from the drive input members to the insert so as to cause the insert to be rotated. while the mandrel is properly fitted and located as aforesaid within the screwthreaded bore thereof. and thereby to enable said insert to be screwed home in said prepared bore in said workpiece member under an axial pressure. also provided or derived from said input drive, applied through said axial limit stop; and swage means operable to perform a swaging operation, during use of the tool after said insert has been screwed home in said bore of the workpiece member, to effect forcible expansion of said annular wall portion of the insert counterbore radially outwards for locking and firmly securing the insert in place; at least two said component parts of the tool being displaceable relative to one another in the axial direction in order to bring about said operation of said swage means.

3. A tool as claimed in Claim 2, wherein

the swage element is in the form of a sleeve member slidably mounted on the drive shaft which is integral with the mandrel and a compression spring is mounted and arranged on said drive shaft for acting on the swage element - to provide the axial swaging drive force, the swage means being operable by retracting said swage element along the drive shaft thereby to compress said spring and then releasing said swage element permitting said spring to expand and drive the swage element axially towards said mandrel.

4. A tool as claimed in Claim 2, wherein the swage element terminates at its rearward end in an exposed end portion adapted to receive a percussive impact force which provides the axial swaging drive force and produces the relative axial displacement movement for carrying out the swaging operation.

5. A tool as claimed in Claim 1, wherein the mandrel has an external screw-thread for engaging the internal screw-thread in the bore of the insert and is operatively connected to the drive input member, for the transmission of rotary drive therebetween, through coupling means including a co-axial drive shaft, and wherein the swage means includes a swage element operatively connected to a swage drive member which is separated from and movable relatively to the said drive input member that receives the input drive for screwing home the insert, said swage drive member being operable to displace the swage element and perform the swaging operation, when in use. by application of a non-percussive drive force to said swage drive member after screwing the insert into place.

6. A tool as claimed in Claim 5. wherein the swage element is in the form of a sleeve member, co-axial with the drive shaft, having a nose portion providing a cam form annular swaging surface and forms part of a telescopically slidable assembly of the tool which. in use. is attached to a rotary drive implement which provides the external rotary drive source, and the swage drive member forms part of a manually operable lever mechanism of the tool arranged to control relative sliding movement of said telescopic sliding assembly and thereby axial sliding movement of the swage element to force the nose portion thereof into swaging engagement with the insert during use.

7. A tool as claimed in any of Claims 2 to 6. wherein the axial limit stop is provided by a fixed collar on the drive shaft adjacent the innermost end of the mandrel.

8. A tool as claimed in Claim 5, wherein the drive shaft is integral with a nose portion and with the mandrel. said nose portion constituting the swage element and providing a cam form annular swaging surface, and said swage means is operable, in use, by a rotary swaging drive applied to said drive shaft so that the mandrel screws axially into the insert and thereby causes the swage element to enter the counterbore of the insert and force said annular swaging surface into swaging engagement with the annular wall portion of the insert counterbore, said drive input member being operatively connected to the drive shaft through a unidirectional drive coupling arrangement for transmission of rotary drive thereto when the insert is being screwed home in the bore of the workpiece member but which permits the drive input member to remain stationary when the drive shaft is rotated by said rotary swaging drive during the swaging operation, said drive input member being provided by a body that also provides the axial limit stop which is formed by a terminal end face thereof that, during use, engages the end of the insert and also the surface of the workpiece adjacent the bore in which the insert is fitted.

9. A tool as claimed in Claim 1, wherein in use the swage means is operable to perform the swaging operation by applying a non-percussive swaging drive force, in the form of a rotary drive and/or axial pressure drive, to said drive input member such that the screwing home fitting operation and the swaging securing operation can be carried out consecutively in a continuous process.

10. A tool as claimed in claim 9, in which, for transmitting the input drive to the insert for screwing into the bore of the workpiece, the mandrel is operatively connected to the drive input member so as to rotate therewith and is provided with an external screw-thread whereby, in use of the tool, said external screw-thread engages the internal screw-thread in the bore of the insert and acts during the screwing home fitting operation to transmit the input drive to the insert in conjunction with the abutting engagement of the axial limit stop, said external screw-thread of the mandrel also providing a holding means effective to retain the insert in place on the mandrel after initially being fitted thereon before being applied to the workpiece bore, said mandrel being disengageable from the insert by application of a rotary drive in a reverse direction to pemit removal of the tool after the fitting and securing in place operations on the insert are completed.

11. A tool as claimed in Claim 10.

wherein the axial limit stop is movable in an axial direction relative to the mandrel and provides an abutment surface arranged so that, in use, when said surface abuttingly engages the insert and also abuttingly engages the surface of the workpiece adjacent to the bore thereof after the insert is screwed home, the subsequent swaging operation can be performed by continuing to apply a rotary input drive so as to cause the mandrel to screw into the insert, producing an axial displacement relative to the axial limit stop and generating thereby axial pressure which operates the swage means.

12. A tool as claimed in Claim 11, wherein said surface of the axial limit stop is provided by an end face having portions extending laterally outwards for engaging the workpiece surface, and the axial limit stop is spring loaded and telescopically mounted for relative sliding movement upon a drive shaft which operatively connects the mandrel to the drive input member.

13. A tool as claimed in Claim 1, wherein the means for transmitting the input drive from the drive input member to the insert for the screwing home fitting operation comprises an element or elements, operatively connected to said drive input member for rotation therewith. providing pressure surface portions engageable frictionally under a radial pressure force component with the annular wall portion of the insert counterbore when the insert is located upon the mandrel.

14. A tool as claimed in Claim 13, wherein the mandrel has a plain cylindrical surface and is connected so as to rotate with the drive input member.

15. A tool as claimed in Claim 14, wherein the pressure surface portions also provide the axial limit stop.

16. A tool as claimed in Claim 13, 14 or 15. wherein the pressure surface portions are adapted to engage the inner surface of the annular wall portion of the insert counterbore under a gripping pressure. directed radially outwards, derived from associated resilient biassing means, thereby to provide holding means effective to retain the insert in place after initially being fitted upon the mandrel before being applied to the workpiece bore.

17. A tool as claimed in Claim 1. wherein the means for transmitting the input drive from the drive input member to the insert for the screwing home operation in the workpiece member comprises an external screw-thread formed on the mandrel thereby to engage with the internal screw-thread in the bore of the insert and act in conjunction with the axial limit stop which in use abuts against the adjacent end of the insert, said mandrel being operatively connected with the drive input member so as to rotate therewith.

18. A tool as claimed in Claim 1 or Claim 17, wherein the mandrel is operatively connected with the drive input member through a unidirectional rotary drive coupling.

19. A tool as claimed in Claim 1 or Claim 17, wherein the mandrel is rigidly interconnected with the drive input member.

20. A tool as claimed in Claim 1 or Claim 17, wherein the mandrel is operatively connected with the drive input member through clutch means.

21. A tool as claimed in Claim 1 or Claim 17, wherein the mandrel is operatively connected with the drive input member through spring loaded frictional coupling means.

22. A tool as claimed in Claim 17, wherein the axial limit stop is movable in an axial direction relative to the mandrel, the arrangement being such that when, in use, said stop abuts against the insert and against the surface of the workpiece member adjacent to the bore after the insert is fully screwed home, the subsequent swaging operation after completing the screwing home fitting operation on the insert can be performed by continuing to apply a rotary drive to the mandrel so as to cause the mandrel to screw into the insert, producing an axial displacement relative to the axial limit stop and generating thereby axial pressure which operates the swage means.

23. A tool as claimed in Claim 22, wherein the axial limit stop has a planar abutment face for abutting against the adjacent end face of the insert, said face having portions extending laterally outwards so as also to engage the surface of the workpiece adjacent to the bore therein when the insert is fully screwed home.

24. A tool as claimed in Claim 22 or 23, wherein the axial limit stop is telescopically mounted for relative sliding moving upon a drive shaft connected to the mandrel.

25. A tool as claimed in Claim 24, wherein the telescopically mounted axial limit stop is spring loaded so that it resets automatically after a swaging operation is completed and the tool is removed from the insert.

26. A tool as claimed in Claim 17, wherein the structure is such that, in use, during the swaging operation no rotary drive is transmitted from the drive input member to the mandrel which remains stationary within the insert whilst a swage element of the tool is moved axially relative to the mandrel in carrying out operation of the swage means.

27. A tool as claimed in Claim 26, wherein the swage element, which acts to apply the swaging or radial expansion force to the insert counterbore wall portion during the swaging operation, is an integral part of a member which also provides the axial limit stop.

28. A tool as claimed in Claim 26, wherein the axial limit stop is not adapted to move relatively to the mandrel during operation of the tool and is located in a fixed spatial relationship with the mandrel.

29. A tool as claimed in Claim 28, wherein the axial limit stop is provided by a tubular member surrounding and secured or locked to a drive shaft which carries the mandrel, said tubular member having a stop surface in the form of an annular end face adapted to abut against the end of the insert and also to engage the surface of the workpiece member when the insert is screwed fully home into the bore therein, thereby automatically controlling the depth to which the insert is fitted within the workpiece bore.

30. A tool as claimed in Claim 28, wherein the axial limit stop is in the form of a fixed collar adjacent the innermost end of the screw-threaded mandrel on a drive shaft integral with the mandrel.

31. A tool as claimed in Claim 30, wherein an additional stop is provided for engaging the surface of the workpiece member adjacent the bore therein when the insert is fitted within said bore, said additional stop being disposed radially outwards of and in fixed predetermined relationship with said fixed collar.

32. A tool as claimed in Claim 31, wherein means are provided for adjusting the fixed predetermined relationship between the additional stop and the fixed collar in a preliminary pre-setting operation of the tool.

33. A tool as claimed in Claim 26 or 27, wherein the swage means is operable by axial pressure provided directly by an axial swaging drive force applied to the tool.

34. A tool as claimed in Claim 28 or 30, wherein a manually operable mechanical device comprising a lever mechanism is incorporated for producing axial pressure to operate the swage means.

35. A tool as claimed in Claim 31 or 32, wherein mechanical means are incorporated which produces or generates axial pressure to operate the swage means from a rotary drive input when the mandrel is held stationary within the insert through the engagement of the additional stop with the workpiece surface during use.

36. A tool as claimed in Claim 35, wherein the mechanical means comprises a cam arrangement which. when operative, acts upon the swage element. said swage element being in the form of a sliding tubular member which is co-axially mounted on said drive shaft and which has a body portion and. at its forward end, a nose potion providing a cam form annular swaging surface.

37. A tool as claimed in Claim 36.

wherein the body portion and the nose portion of the swage element are in the form of separate unconnected parts mounted on the drive shaft, said body portion being spring biassed into engagement with the cam arrangement and the nose portion being freely mounted in captive floating relationship.

38. A tool as claimed in Claim 1, wherein the swage means comprise a swage element or elements providing a cam form swaging surface, said swage element or elements being arranged to move axially during the swaging operation under an axial swaging force so as to enter the counterbore of the insert whereby the cam form swaging surface engages the annular wall portion of the latter and applies an outwards radial component of pressure to expand said wall portion.

39. A tool as claimed in Claim 38, wherein the mandrel has an external screwthread thereby to engage the internal screwthread of the insert in use of the tool and said mandrel is arranged so that during the swaging operation it can receive a rotary drive whereby to screw into the insert and generate the axial swaging force, the swage element or elements being integral or rigidly connected with the mandrel so as to rotate during the swaging operation and carry out the swaging of the annular wall portion of the insert counterbore with a rolling action.

40. A tool as claimed in Claim 38. in which a single swage element is provided which is slidably mounted for axial movement, being in the form of a tubular sleeve member telescopically mounted on a drive shaft portion connected to or carrying the mandrel.

41. A tool as claimed in Claim 40, wherein means are provided for controlling the depth to which the swage element enters into the counterbore of the insert, said means being adjustable so as to preset the axial position of the swage element. at the end of its swaging movement. relative to said axial limit stop.

42. A tool as claimed in Claim 1, wherein the swage means comprises a swage element or elements arranged to expand or move outwards radially within the counterbore of the insert during the swaging operation, in response to relative axial displacement of a swage actuating drive element coacting therewith.

43. A tool as claimed in Claim 42.

wherein the swage actuating drive element coacts with the swage element or elements by mutual abutting engagement through cam form surfaces during said relative axial displacement.

44. A tool as claimed in Claim 43, wherein the swage actuating drive element comprises a shaft portion having a tapering profile which is adapted to be displaced axially relative to the swage element or elements which is or are provided by a coaxial radially expandable tubular member or by radially displaceable pressure elements located in a carrier formed by a coaxial tubular body.

45. A tool as claimed in Claim 43, wherein the swage actuating drive element forms part of an axially movable drive shaft adapted to act through a thrust bearing surface against an internal tapering surface of a coaxial radially expandable tubular member in the form of a spring-loaded split collet providing the swage element or elements.

46. A tool as claimed in any of Claims 42 to 45, in which the swage element or elements comprise a member or members which also provide the axial limit stop and stop surface portions adapted to engage the surface of the workpiece member adjacent the bore therein when the insert is fully screwed home.

47. A tool for use in the fitting and securing in place of a thin-wall screwthreaded insert. of the kind referred to. in a complementary screw-threaded bore prepared in a workpiece member, said tool being constructed and arranged substantially as herein described and illustrated with reference to Figure 2 of the accompanying drawings.

48. A tool for use in the fitting and securing in place of a thin-wall screwthreaded insert. of the kind referred to, in a complementary screw-threaded bore prepared in a workpiece member, said tool being constructed and arranged substantially as herein described and illustrated with reference to Figures 3 and 4 of the accompanying drawings.

49. A tool for use in the fitting and securing in place of a thin-wall screwthreaded insert. of the kind referred to. in a complementary screw-threaded bore prepared in a workpiece member. said tool being constructed and arranged substantially as herein described and illustrated with reference to Figures 5 and 6 of the accompanying drawings.

5(?. A tool for use in the fitting and securing in place of a thin-wall screwthreaded insert. of the kind referred to. in a complementary screw-threaded bore prepared in a workpiece member, said tool being constructed and arranged substantially as herein described and illustrated with reference to Figure 7 of the accompanying drawings.

51. A tool for use in the fitting and securing in place of a thin-wall screwthreaded insert. of the kind referred to, in a complementary screw-threaded bore prepared in a workpiece member. said tool being constructed and arranged substantially as herein described and illustrated with reference to Figures 8 and 9 of the accompanying drawings.

52. A tool for use in the fitting and securing in place of a thin-wall screwthreaded insert, of the kind referred to, in a complementary screw-threaded bore prepared in a workpiece member, said tool being constructed and arranged substantially as herein described and illustrated with reference to Figures 10, 11 and 12 or as modified with reference to Figures 10a, ila and 12a of the accompanying drawings.

53. A tool for use in the fitting and securing in place of a thin-wall screwthreaded insert, of the kind referred to, in a complementary screw-threaded bore prepared in a workpiece member, said tool being constructed and arranged substantially as herein described and illustrated with reference to Figure 13 of the accompanying drawings.

54. A tool for use in the fitting and securing in place of a thin-wall screwthreaded insert, of the kind referred to, in a complementary screw-threaded bore prepared in a workpiece member, said tool being constructed and arranged substantially as herein described and illustrated with reference to Figure 14 of the accompanying drawings.

55. A tool for use in the fitting and securing in place of a thin-wall screwthreaded insert, of the kind referred to, in a complementary screw-threaded bore prepared in a workpiece member. said tool being constructed and arranged substantially as herein described and illustrated with reference to Figure 15 of the accompanying drawings.

56. A tool for use in the fitting and securing in place of a thin-wall screwthreaded insert, of the kind referred to, in a complementary screw-threaded bore prepared in a workpiece member, said tool being constructed and arranged substantially as herein described and illustrated with reference to Figures 16 and 17 of the accompanying drawings.

57. A tool for use in the fitting and securing in place of a thin-wall screwthreaded insert, of the kind referred to, in a complementary screw-threaded bore prepared in a workpiece member, said tool being constructed and arranged substantially as herein described and illustrated with reference to Figure 18 of the accompanying drawings.

58. A tool for use in the fitting and securing in place of a thin-wall screwthreaded insert, of the kind referred to, in a complementary screw-threaded bore prepared in a workpiece member, said tool being constructed and arranged substantially as herein described and illustrated with reference to Figures 19 and 2() of the accompanying drawings.

59. A tool for use in the fitting and securing in place of a thin-wall screwthreaded insert, of the kind referred to, in a complemntary screw-threaded bore prepared in a workpiece member, said tool being constructed and arranged substantially as herein described and illustrated with reference to Figure 21 of the accompanying drawings.