US2107581A - Tool retainer - Google Patents

Description

Feb. 8 193 8.

J. H. PARSONS ET AL TOOL RETAINER Original Filed Oct. 31, 1932 3 Sheets-Sheet 2 INVENTOR;

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' TOOL RETAINER I Original Filed Oct. 31, 1932 3 Sheets-Sheet 3 INVENTOR $707211 27G Pafsons Patented Feb. 8, 1938 PATENT OFFICE TQOL RETAINER John 1]. Parsons, Bloomfield Hills, and Lawrence 8. Lamb, Groase Pointe Park, Mich.

muting. owner a1, 1932, Serial No.

Renewed July 9, 1937 12 Claims.

This invention relates to tool-retaining devices, such as are commonly used to retain punches, dies, drills and the like in their holders. It is usually desired that'tools of this class be interchangeable in their holders, and various means have in the past been employed to removably secure them. Such previously used retalning means have been unsatisfactory for a number of reasons. Those so designed as to retain the tools with adequate firmness necessitated the expenditure of too much time and trouble in attaching and removing the tools. while many of those designed to permit rapid interchanging of the retained tools have not provided adequate security. Some such retainers designed for quick action provide adequate security for circular punches, for example, but not.

such-shanks frequently dare not employ them;

as in order to do so safely they would have to carry on hand a prohibitively expensive reserve supply, or special cutting or grinding equipment, to prevent the danger of a tool breakage stopping production.

The primary object of the present invention is to provide a tool retainer subject to none of the foregoing briefly summarized shortcomings and defects, and which, while permitting instantaneous removal and insertion of a tool in the retainer, retains the tool with such firmness as to prevent any possibility of either rotative or endwise movement of the tool with respect to the retainer.

Another object of this invention is the production of such a retainer which is of simple and inexpensive construction. and which is utilizable in conjunction with tools and holders of conventional designs now'in use, merely necessitating slight alterations thereof, to effect which alterations special machinery is not required. I

A further important object is the provision of such retaining means installable in less space than those heretofore used, and without regard to the relative hardnesses of the metal in which the tool shank and the retainer itself are installed.

Another object is the provision of an improved tool retainer so designed that the retainer block need not be specially hardened.

Another important object is the incorporation in such a retainer construction of indicating means enabling easy determination by the operation as to whether ornot the tool is properly locked in the retainer. 7

A still further object is the provision of improved pilot means insuring insertion of the tool in the retainer in the proper manner.

Another object is the provision of an improved retainer block construction enabling mounting interchangeably retained tools on closer centers. I

Another object. is the provision of means for interchangeably mounting a series of tools in an elongated retainer without the necessity of regrinding each tool socket or other aperture after a hardening operation to correct inaccuracies so introduced, but in which an unhardened re- 7 tainer is used with inserted sockets or the like individually hardened, together with improved means for sup rting tools of unusual length.

Other obiec's and advantages will be apparent from the following description whereinreference is made to the accompanying drawings illustrating preferred embodiments of our invention, and wherein similar reference numerals designate similar parts throughout the several views. y

In the drawings:

Figure 1 is a vertical sectional view taken sub-' stantially longitudinally through a punch retainer incorporating the principles of our invention, showing a punch secured therein, and also fragmentarily showing a punch holder, stripper plate, a piece of sheet stock being worked upon, and a die;

Figure 2 is a top plan view of the punch retainer removed from the backing plate and punch holder, taken substantially on the line 2-4 of Figure l and looking in the direction of the arrows;

Figure 3 is a fragmentary top plan view with the backing plate in place, taken as if on line 3-3 of Figure 1;

Figure 4 is a fragmentary top plan view of the punch and detent;

Figure 5 is a fragmentary detail section similar to Figure 1 in the parts shown, but i11ustrating the punch released, or before being secured;

Figure 6 isa similarly taken fragmentary sectiontof a somewhat modified punch retainer inpiloting device carried by the stripper plate;

Figure 8 is a top plan view of a plurality or retainers of this form arranged in series, show= ing the holder in one instance prepared for the retainer and tool which are not yet installed;

Figures 9 and 10 are top and side views respec- 'tively of the tool socket bushing;

' its insertion in the retainer.

, Figure 11 is a top plan Vi8W,'&1SO with the backing plate removed, of another series-mounting arrangement for punches, four of which are shown installed;

Figure 12 is a top plan view of a plurality of our improved retainer blocks of different sizes arranged in interfitting relation; and

Figure 13 is a similar-view showing another arrangement.

Referring now to the drawings: Reference character represents the main block or body of a punch retainer, utilized as illustrative of a typical application of our invention. A cylindrical bcre 2| is formed therein adapted to receive a punch shank, as the shank 22 of the punch.23. A transverse groove is formed in and adjacent the upper end of the shanld of the punch, as indicated at 24, Figures 1 and 5. The preferred form of this groove is clearly shown in the drawings, from which it will be observed that a generally plane anguiarly arranged surface 24' forms its upper wall. The top edge of the punch may also be chamiered, as at 25, to: facilitate A depression is formed in the top of the retainer block 20 adjacent the upper extremity of the tool shank socket 2|. This depression may take the form of a simple miiied slot 26 disposed transversely of the hiock, as shown in Figures 1 and 2." Terminating in the slot 26 and vertically arranged beside the punch socket 2| is a bore 21 havinga' reduced upper portion". Vertically reciprocable in the aperture 2'|28 is a stem 29,

carrying a cupped collar and spring abutment,

. aperture and bears at its other end-against member 30 to urge the pin downwardly. Secured to the upper extremity of the pin and arranged transversely thereof is the wedglngcam member 32, which is housed within the depression formed by the slot 26, and of course also serves as a stop to limit downward movement of the pin 29. Also within the depression formed by the slot 2G, slidably fitting between the bacfing plate and the bottom of the slot and arranged between the wedging member 32 and the punch socket 2|, is

i the locking detent 33, the central portion of the wedge 32 as the latter is forceddownwardly under the influence of the spring 3|. In order to position the detent 33 and prevent its sliding from the recess 26, it may be formed with rearwardly projecting ends 34 engaging the'sides of the wedge 32, as shown in Figures 2 and 3. The

locking surface 35 of the detent may be partly cylindrical, so that it contacts the locking surface 24' or the punch shank groove along a straight line, and the lower surface of the detent which 1 overhangs the socket may be angularly cut ,out, as at 36, to form a cam surface engageable by the chamfered upper end of the punch shank by which the detent may be forced clear of the socket as the punch is inserted when the wedge is released.

The angle between the wedge member 32 and the rear face of the detent 33 is such that the wedge cannot be forced upwardly by pressure in thedirection of the arrow 31 exerted through the detent. While-as above pointed out, the surface 32' of the wedge 32 and the rear surface 33 of the detent 33 are arranged at a wedging angle, so that'the wedge cannot be urged upwardly by lateral pressure exerted through the detent, the inclined engaging surface 24" of the punch shank aperture is not arrangedat a locking angle relatively to the portion of the locking surface 35 of the detent it engages, so that when the detent is released by upward movement of the wedge memher, a retained tool may be removed from the socket by merely pulling the same downwardly, the detent'member being thereby forced laterally in the direction of arrow 3! and out of the tool socket. The wedge is moved upwardly by pushing upwardly upon the plunger 30, either manually,

or if it is inaccessible, by 'means of a suitable tool (not shown). The plunger, of course, may or may not project from its aperture 21, depending upon the clearance available in the particular tool installation. If the plunger cannot project, any pointed or suitably sized member may be inserted in the aperture to enable forcing the plunger inwardly. In order to permit insertion of the punch the detent is first released, so that it is free to move laterally, by pushing the wedge 32 and associated parts upwardly, after which the shank of the punch may be inserted in the socket, the chamfered surfaces 36 cooperating to force the detent out of the socket, permitting full insertion of the tool, after which release of the upward pressure against the plunger permits the wedge 32 to move downwardly, forcing the detent 33 back into the punch socket, and into engagement with the slot 24 in the punch shank. The tool is thereupon locked against removal, since no amount of force in the direction 31 gen erated by downward pull upon the tool is suilicient to force the'wedge 32 upwardly. It will be noted that the engagement of the locking surface of the detent with the inclined surface 24 of the punch shank slot tends to force the punch upwardly within its socket, and thus'maintains the top of the punch in engagement with the top of the socket, preventing longitudinal reciprocation. or slopping of the punch shank in the socket, which might, upon subjection of the tool to hard and rapid usage, result in peening of the upper end of the punch shank, or crystallization of the metal subjected to the percussion thus generated. The top of the punch socket and retainer recess 26 may if desired be closed by a backing plate, as 39, secured to the top of the plate 20 in any suitable fashion, as. by the same screws 40 which-secure the retainer block to the punch holder 4|. In the backing plate is formed preferably of reamer drill size, and the block.

a clearance slot or aperture 42 wherein the wedge member \32 is permitted to move upwardly, as

shown in\ Figure '5.

Preferably the shank of the tool is flattened as at 43 immediately above the locking slot, and the detent'is movable rearwardiy only far enough to permit full insertion of the tool when this flat 43 is aligned with the detent, which thus also serves as a pilot preventing improper insertion of the tool with the locking groove disaligned with the detent.

Although only parts of the illustrative punch press appear in the drawings, it will be seen that in Figure 1 a "button die is shown arranged for cooperative reception of the punch. The die, whether of this or any other removable type, may of course also be positioned by one of our improved retainers, although a showing thereof is not included, inasmuch as it would serve merely to unnecessarily elaborate the drawings.

It will be seen that close size Ilmits need not be observed in forming the locki lfl P rts or the apertures in which they move, and that the detent 33, wedge 32 and rod 2! may be formed of bar stock which is rolled in manufacture to the desired cross section, and then out oil to the desired lengths.- The retainer block 20 may be of low carbon steel, which is copper-plated before final reaming of the punch socket 2i and detent slot 26, after which it may be case-hardened upon only these surfaces from which the copper-plating has been removed. The apertures 44 are being unhardened, it may in assembly upon the tool be positioned upon the punch holder, the holes drilled in the latter by means of a full sized drill, using theblock as a template, and both apertures then reamed at once, thus making disalignment virtually impossible.

By reason of the lateral engagement of the rearward extensions 34 of the detent with the sides of the wedge member, the detent is positively positioned against lateral displacement without the necessity of employing any other guides except the backing plate and the bottom of the slot 26. Thus the slot may be opened at its ends, and thus also a plurality of detents and wedge members may be arranged in a single elongated slot when a series of punches is employed. Note in this connection the typical series arrangement shown in. Figure 8, in which the single elongated slot 26=is designed to accommodate a piuralityof detents 33 and interfitting wedge members 32 the former of which engage a. plurality of punches as 23 having their sides carrying the retaining grooves exposed to the slot. The series arrangement shown in this view will presently be described in greater detail.

In Figure 6 is shown an illustrative embodlment typifying the ease with which our improved retainer is installable in tool assemblies now considered impossible of adaptation to interchangeable retainers. In this construction, which will be recognized as typical, aforming or shearing blade 45 is carried by the press adjacent the punch 23", the punch retainer block 20' being thereby necessarily limited in size; If, as in the construction shown, one of the seeming screws as 4!! lies immediately behind the punch, it becomes a difficult matter to install an interchangeable retainer of any of the types now known, as if an attempt is made to put ordinary retainers in the body of the blade member 45 in the manner in which our improved retainer is shown installed, the differences of hardness of the metals, of the shearing blade and the retainer block, through the thin wall of which between the blade and punch shank the detent must project, make it impossible to hold the aperture through which the detent works to close limits, or to hold the two sections of the aperture in exact alignment. If then the design of the interchangeable retainer .is such as is commonly the case, that the detent and its aperture must fit to close limits, such an installation islmpossible. With our improved construction on the other hand, the detent works through what may be termed a clearance: slot only. The size limits of these parts are relatively unimportant and need not be close. The locking means may be installed in the body of the blade in the manner shown in Figure 6, with the detent member 33 projecting through an aperture (undesignated) in the front of the block 20. The plunger 30 by means of which the punch is released is then also easily accessible from the front of the tool, making this a desirable method of installation even though there might be room for the retainer in the block 20 behind the punch. Analogous parts to those shown and described in connection with the first embodiment will be seen to have been. given like reference numerals with the addition of prime exponents. Their similar funotioningwill be easily understood, and detailed repetition of the description of these parts will accordingly be omitted as unnecessary.

Figure '7 shows another somewhat modified form particularly adapted for use in connection with long punches which project farther from the holder than is usual. Such a punch is shown at 23 In this embodiment 'the punch socket is formed of an individually hardened and ground bushing 2| which may be press fitted in the unhardened retainer block 20 and provided with a flange as 43 at itsupper end which serves to additionally position it when clamped beneath the backing plate 39 upon assembly of the retainer upon the punch holder in the manner shown. The socket bushing 2| projects down wardly from the retainer block to form a support for the elongated punch shank, as clearly shown in the drawings. The top of .the socket bushing is cut away as. at 4'! (Figures 9 and 10) to permit the detent member 33 to enter the locking groove 24 in the tool shank. If a stripper plate as 48 which is rigidly fixedto the bed or table of the machine is employed, it may carry a pilot bushing as 49 adapted to serve as a guide for the socket bushing 2 i to properly align the punch with the die 50, and thus prevent damage to either in event of any sloppiness in the punch holder-a common condition. The remaining analogous parts have been given like reference numerals with cube exponents.

As shown in Figure 8, the socket bushings 2i form a convenient means whereby a. number of punches. may be arranged in an elongated series in a retainer bar as 20 which may be of unhardened metal. At the present time great difficulty isencountered in arranging a long series of punches in a single bar carrying interchangeable retainers for cooperation with a similarly arranged series of dies which are usually also mounted in an elongated bar, as after drilling the socket holes the bars must be hardened, .70

bar may be left unhardened and the holes for the socket bushings 2| drilled upon proper centers, the bushings which are of course previously hardened and ground, (a simple production operation upon such pieces) are then press fitted into the bar, which is then completed insofar as the arrangement of the punch sockets therein is concerned. The die bar is oi course similarly formed, and it will be understood that the same retaining means is preferably employed in conjunction with the dies (and that it is equally adaptable to other tools as well). The detent members as 33 and wedges as 32 may be housed in a single elongated slot 28 traversing the bar.

As indicated in Figure 11, more than one tool as 23 may be held by a single detent, as 33 tainer blocks and backing plates is best brought out in plan 'view Figures 12 and 13, showing typical nestings of punch retainers of various sizes, and bringing out the manner in which their shaping permits arrangement of a plurality of punches on close centers though mounted instandardized retainers; As shown in Figure 12 the nose of each retainer block as 20 is rounded concentrically about the axis of thepunch socket 35 H and is filleted or flared outwardly as at 53 to meet the side walls of the retainer only at a point well back of the nose of the block and punch axis. This back radius of the flare .is preferably greater than the nose radius of the largest block, which assists the interfitting of the retainers, as shown, with a minimum spacing less than is ordinarily obtainable.

While it will be apparent that the illustrated embodiments of our invention herein disclosed are well calcuiated to adequately fulfill the objects and advantages herein stated, it is to be understood that the invention is susceptible to ,variation, modification and change withinfthe spirit and scope of the subjoined claims.

What we claim is:

1. In a tool retainer, a block member having a tool socket therein and a depression in its rear surface adjacent and intersecting the socket,

a backing plate arranged over the depression, a

detent member slidable in the depression between and confined by the bottom of the latter and the backing plate which thus cooperate to form a slideway, said detent member having an inclined rear surface, an actuating member for.

' in adapted to receive the tool shank, a detent t me is projected to wardly of the socket.

thereofabutting the detent, and being adapted when the tool is so fully inserted and the detent engage in the slot in the tool shank.

3. In a metal forming device, a holdena bladelike forming member carried thereby, a tool retainer block carried by the holder adjacent the blade and having a tool sockettherein, a channel formed of registering openings in the blade member and retainer block, and tool locking means carried by the blade member and including a .detent in the channel movableinwardly and out- 4. In combination with a tool having a transversely slotted shank, a tool retainer comprising a member socketed to receive the tool shank, a detent member projectable into, the socket to engage the slot in the tool shank and movable therefrom to release the same, a wedging member arranged substantially behind the detent member for looking the detent member in projected position, and means for moving the'wedge member to lock or release the detent at will, the slotted area of the tool shank engaged'by the detent being disposed at a large angle relatively to the tool socket, whereby the detent urges the toolfarther inthe socket as the detent is forced toward the shank.

5.- In combination with a tool retainer having a socket therein, a tool having a shank insertable in the socket, the shank being provided with a transverse depression having an inclined face arranged at a large angle relatively to the shank, a detent member having a portion curved about an axis transverse to that of the socket and projectable into the socket for cooperative engagement with the inclined face of the depression in the shank, whereby the detent engages the tool shank along a transverse line, and upon being urged thereagainst urges. the tool shank inwardly of the socket.

6. In a tool retainer, a block member having a tool socket therein and a depression in its rear surface adjacent and intersecting the socket, a backing plate arranged over the depression and having an aperture therein also overlying part of the depression, a detent'member in the depression confined by the bottom thereof and by the backing plate and slidable therebetween and inwardly and outwardly of the tool socket, and an actuating member for the detent movable transversely of the groove and backing plate and in the aperture in the latter.

7. In combination with a tool having a shank, a depression in the side of the shank, and a longitudinally' arranged guiding portion carried by the shank and extending from the depression :to its end, a retainer comprising a block having a tool socket therein, a detent carried by the block and movable inwardly and outwardly of the socket but having a portion adapted to project partially into thev tool socket when the detent is fully retracted and engageable with the guiding portion of the tool shank while the tool is being inserted to prevent insertion of the tool except with such surfaces in desired relation.

8. In a metal forming device, a holder, 9. bladelike forming member carried thereby, a punch, and means for removably supporting the punch in the holder, comprising a retainer carried by the holder having a socket therein for the punch and arranged adjacent the blade, the blade member and retainer having aligned apertures therein forming a channel intersecting the socket, and punch locking means including a detent movable in said channel in and outwardly of the socket and operable from the opposite side of the forming member to that occupied by the socket.

9. In combination with a tool having a shank and a transverse slot in the shank, a tool retainer comprising a, member socketed to receive a tool shank, a detent member projectable into the socket to engage an upper surface of the slot in the tool shank, a wedging member for maintaining the detent in projected position, said upper surface of the slot in the tool shank beingarranged at less than a wedging angle with respect to the direction of projection of the detent member, whereby the engagement of the detent and said surface of the slot in the tool shank urges the tool inwardlyof the socket as the detent is urged toward the shank, and means for releasing the wedge member.

10. Means for removably supporting a plurality of tools, comprising an elongated retainer having a plurality of tool sockets therein and extending substantially therethrough, a channel extending along the opposite surface of the retainer from which the tools are intended to project and intersecting the sockets, a plurality of detents arranged in the channel and so movable transversely thereof that one may be projected laterally into and substantially withdrawn from each socket, an actuating cam member arranged behind each detent, means for moving the cam members to force the detents into the sockets, and engaging portions carried by the cam members and detents adapted to prevent displacement of the detent members .along the channel without preventing the described actuative movement of the detents.

11. In a tool retainer having a socket therein and a channel transversely intersecting the socket and wider than the maximum width of that part of the socket which it intersects, a detent member slidable in the channel" toward and from the axis of the socket and soiinwardly and outwardly thereof, said detent extending into said portions of the channel wider than the intersected part of the socket and being supported by said portions when projected into the socket.

12. In a tool retainer having a socket therein, a detent member having a portion curved about an axis transverse to the socket and projectable thereinto, said detent having a supporting base portion projecting at either end beyond the intersected portion of the socket and within the peripheral line thereof whenyiewed from the side, said detent having a substantially flat inclined rear surface, and a wedging cam arranged behind the detent and having a similarly inclined flat surface in engagement therewith.

JOHN H. PARSONS. mwarmca s. 1m.

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