US3399817A - Devices for driving pins into masonry, structural members or the like - Google Patents

Description

K. D'IEHL 3,399,817

STRUCTURAL Sept. 3, 1968 DEVICES Foa DRIVING PINS INT0 MAsoNRY,

MEMBERS oR THE LIKE Filed sept. I, 1965 Nq Nm Y I l I l H Ov mv N @E qq n mv MY ov United States Patent O 7 claims. (ci. 227-10) ABSTRACT F THE DISCLOSURE A device for driving pins into masonry or the like in which a cartridge holder is arranged in a housing of the device movable from an inactive position to a cocked position upon insertion of a pin in the muzzle of the device and exertion of forward pressu-re on the latter, wherein a piston driven forwardly upon detonation of a charge in the cartridge holder drives the pin into the masonry, and wherein the piston and elements of the device for Cooperating therewith are constructed and arranged to cooperate with each other to brake forward movement of the piston with a force increasing during forward movement of the latter.

The invention relates to a device for driving pins into masonry, structural members or the like, having a housing, in the interior of which there is accommodated a displaceable piston, which co-operates with the pin to be introduced from the muzzle side, and a cartridge holder, which is displaceable longitudinally land is situated spaced from a release mechanism when the device is in the uncocked position, and which can be transferred into a position of readiness for detonation by the pin bearing against the masonry or the like when the device is cocked upon exertion of forward pressure on the latter; the position of readiness for detonation remaining the same regardless of the length of the pin to be driven in. Such known devices for driving pins into masonry have the advantage that the transfer into the position of readiness for detonation is only possible with a pin inserted.

It is the object of the invention to improve devices of the aforesaid kind, while retaining the advantages of known embodiments as outlined. According to the invention, this object is achieved essentially in that an abutment on the pin serves to transfer the cartridge holder into the position of readiness for detonation, preferably with the interposition of a guide sleeve.

In the preferred embodiment of the invention, the abutment is constructed in the form of a disc placed over the circumferential area of the pin. In this case, it is advisable to hold the disc and/ or the pin by means of magnets let into the guide sleeve.

In devices for driving in pins, which are also called piston devices, the problem arises of dissipating the energy which is not used to drive in the pin, in the device itself, in such a manner that the device still remains capable of operation and none of the parts of the device are destroyed after only `a few cartridges have been fired. In the construction of such a device according to the invention, a step-by-step dissipation of energy at various parts and points in the device is proposed, the individual stages becoming either wholly or only partially effective depending on the material to be fired into. The rear end of the guide sleeve, which comes into operational communication with the cartridge store, is used as a first braking stage, and this end serves to brake the piston as it moves forwards. As a rule, this first braking stage suffices to dissipate the energy not used to drive in the pin, when hard ICC materials such as steel, concrete or the like are fired at. On the other hand, if complete dissipation of the unused energy has still not been effected, for example when softer materials such as hollow building blocks are tired at, then one or more further braking stages come into action.

If it is desired to achieve particularly strong braking, then according to a further proposal of the invention, the rear, reinforced region of the guide sleeve is constructed in the form of a member which can be expanded by the piston striking against it. The expansion may be effected in such a manner that the circumferential area of the expanded region co-operates with inner walls of the housing so that a strong friction occurs there. The expansion can be facilitated as a result of the fact that slits are provided in the rear zone of the guide sleeve so that a plurality of expansible segments are formed. For example, four expansible segments, preferably of like formation, can be provided by means of two slits arranged crosswise for example.

The guide sleeve in the device according to the invention for driving in pins has a continuous bore in which the rear portion of the pin engages from one side and a pin-shaped extension of the piston engages from the other side. Normally, the end face of the pin-shaped extension on the one hand and the head of the pin on the other hand are situated at a distance apart, and indeed a large gap is normally left between these two parts. This has the decisive advantage that pins of different length can easily be fired with the device according to the invention.

In the device according to the invention for driving in pins, it is advisable to guide the guide sleeve in a protective cover which is connected to a tubular cover by a circlip. The protective cover is displaceable by a short, fixed amount, in relation to the tubular cover. The purpose of this displacement is not adaptation to different lengths of pin to be inserted but to compensate for irregularities on the surface being fired into; in addition, the possibility is thus afforded of these parts of the device cooperating in the yielding motion of the device after the firing of a shot. The rear guide sleeve comprising the cartridge store, preferably comprises gas discharge ducts running obliquely. These gas discharge ducts bring the combustion chamber into communication with a compartment which lies between the outer wall of the guide sleeve and parts of the inner wall of the housing. When a specific distance has been covered by the piston during the firing of a shot, then the combustion chamber is vented as :a result. The gases escaping through the gas discharge ducts act, at the same time, on the rear outer breechblockmechanism parts of the device, so that these are also at least partially used to take up the recoil.

Further `details of the invention are apparent from the following specific description.

Several examples of embodiments of the invention are illustrated in the accompanying drawings in which:

FIG. l -shows a longitudinal section through the device aocording to the invention for driving pins into masonry, in the uncooked condition;

FIG. 2, likewise in longitudinal section, shows the device of FIG. 1 but in the cocked position, with parts broken away;

FIG. 3 shows Aa further example of the -device according to the invention, likewise with parts broken away, after the pin has been driven in; and

FIG. 4 shows the ydevice of FIG. 3 in a position before the pin has been driven in.

Mention may first be made of the fact that the release mechanism does not form part of the invention. Thus the embodiment of the release mechanism on which the construction according to the example is based serves only to demonstrate the mode of operation of the device. The construction of this release mechanism is known per se; if necessary, it may be replaced by other release mechanisms, likewise known. Only a few parts of the release mechanism are therefore explained in the following speciic description.

The device for driving pins into masonry or the like has a protective cover which is connected to a following tubular cover 11. The protective cover 10 is displaceable by a short xed amount, in relation to the tubular cover 11. This slight displaceability of the said two parts is selected in order to compensate for irregularities on the surface being tired into and to participate in the yielding movement of the device after the tiring of the Shot. In order to receive the tubular cover 11, the protective cover 10 is provided with an annular groove which is open towards the free end face and in which the free end of the tubular cover 11 engages. In order to obtain the said displacement, two annular grooves are provided, one of which is allocated to the protective cover 10 and the other to the tubular cover 11. The two annular grooves 13 and 14 co-operate with a circlip 12. The annular groove designated lby 13 and allocated to the tubular cover 11 is adapted in width to the circlip 12 so that this is received by the annular groove 13 so as to be held against ydisplacement in the axial direction. The annular groove 14 which is allocated to the protective cover 10 has a greater width in comparison. Thus it can be seen that a displacement of the protective cover 10 in relation to the tubular cover 11 is possible in the axial direction by an amount which corresponds to the difference in width between the annular groove 13 and the annular groove 14. If necessary, the protective cover 10 and tubular cover 11 can be detached from one another. As can be seen from the figures of the drawings, the annular 'groove 13 in the tubular cover 11 is deeper than the thickness of the circlip 12. For detachment, the circlip 12 is pressed completely into the annular groove 13, which is preferably effected from the outside through apertures, not illustrated, in the protective cover 10. It is clear that the protective cover 10 can then be withdrawn from the tubular cover 11.

At the opposite end of the tubular cover 11 from the protective cover 10, the tubular cover is connected to a breech ring 15. In the example, the connection is effected by means of a screw thread 16. This detachable connection formed by the screw thread 16 can be used, for example, when internal parts of the device have to be changed or if it is desired to clean the device.

The internal parts received by the protective cover 10, the tubular cover 11 and the breech ring 15 are: a front guide sleeve 17, a rear guide sleeve 18 and a piston 19.

The front guide sleeve 17 has a bore 20 which extends in the longitudinal direction and has a uniform diameter throughout. On the other hand, the guide sleeve 17 has two regions which differ in external diameter. These are a front region designated yby 21 and having a smaller diameter and a rear region 22 of a larger dimeter. Both regions 21 and 22 of the guide sleeve 17 are guided substantially against the inner rwall of the protective cover 10. The rear region 22 is received by a bore 24. The diameters of the respective regions 21 and 22 of the guide sleeve 17 on the one hand and the diameters of the 'bores 23 and 24 of the protective cover 10 on the other hand are adapted to one another in such a manner that the guide sleeve 17 is received in the protective cover 10, to be easily movable therein. The shoulders 25, 26, rwhich are formed as a result of the different diameters, are curved when seen in cross-section, the shoulder 25 on the guide sleeve 17 resembling a illet, while the shoulder 26 of the protective cover 10 is adapted to the shoulder 25 in such a manner that the shoulders 25 and 26 can bear one against the other over their area.

The bore already mentioned in the guide sleeve 17 ends, at the inner end face of the guide sleeve 17 in a funnel-shaped widening 27 which is only low in height.

This co-operates with parts of the piston 19, as will be described in detail later. The opposite end, that is to say the end facing outwards, of the guide sleeve 17 is kept smooth, on the other hand. A plurality of permanent magnets 28, which extend in the same axial direction as the bore 20, are let into the region 21, their front end faces being flush with the end face of the guide sleeve 17. The permanent magnets 28, which are mounted equidistant apart in the guide sleeve, serve to hold a pin 29 which is received in the bore 20. The diameter of the head of the pin 29 corresponds substantially to the diameter of the bore 20 so that the pin 29 is guided at its rear end as a result. Guiding and holding at the other end of the pin 29 is afforded by an abutment in form of a disc 30. This is drawn over the shank of the pin 29 and lies with its circumferential face against the inner wall of the bore 23 in the protective cover 10. After the pin 29 has been pushed in, the magnets 28 hold it firmly in position through the disc 30.

The rear guide sleeve 18 comprises various regions distinguished by different diameters, not only inside its bore extending in the longitudinal direction and generally designated by 31, but also at its outer circumferential surface. The bore 31 is, on the one hand, adapted to the piston 19, and on the other hand, one component region of it serves as a cartridge store 32. Over about two thirds of its length, the bore 31, beginning with its free front end, is kept uniform in diameter. This component region is designated by 33 and serves to guide the longitudinally displaceable piston 19. The region having the largest diameter, namely the guide region 34, of the piston 19, bears against theinner wall of the component region 33. At each side of the guide region 34, the piston 19 has pin- like extensions 35, 36. The longer, 35, of the two, faces towards the muzzle of the device; its diameter corresponds substantially to that of the bore 20 in which it engages partially, Its length is selected in such a manner that its front end face is remote from the head of the pin so that longer pins than that illustrated can also be driven in. When the piston 19 is in its rearward position, the pin-like extension 36, situated on the other side of the guide region 34, projects into a portion 37 of the bore 31, the diameter of which is smaller than that of the bore 33. Thelength of the bore 37 extends to shortly in front of the cartridge store 32. The space between the cartridge store 32 and the bore 37 is constricted in diameter and is not specifically designated.

As lalready mentioned, the rear guide sleeve 18 has a varied shape which also extends to its outer circumferential surface. Thus about two thirds of the length of the guide sleeve 18 is tubular in shape and is designated by 38. The tubular portion 38 lies towards the front guide sleeve 17 and co-operates, by its end face, with the rear face of the front guide sleeve 17 provided with the funnel-shaped widening 27. As already mentioned, the guide sleeve 18, which, like the guide sleeve 17, can be displaced longitudinally yby the same relatively small amount, is guided by its tubular portion 38 in the tubular cover 11. Further guiding of the `guide sleeve 18 is effected by means of a ange 39, which is enlarged in diameter in relation to the other parts of this guide sleeve 18, against the inner wall of the breech ring 15. The shoulders, at each side of the flange 39, which are not separately designated, serve as stop surfaces and limit the displacement of the guide sleeve 18 yin both directions. The one shoulder, namely that situated towards the muzzle of the device, co-operates `with the rear end face of the tubular cover 11, whereas the other co-operates with an encircling inward-facing extension on the breech ring 15. The rear region 40 of the rear guide sleeve 18 is somewhat smaller in its external diameter than the tubular portion 38. As can be seen from the figures of the drawings, the region 40 receives the greater part of the bore 37, the cartridge store 32 and the region having a constricted diameter situated between these two parts. In the rear region of the rear guide sleeve 18 there are provided gas discharge ports 41 through which the combustion chamber is vented after the piston 19 has covered a certain distance, and at the same time the rear outer parts of the breech mechanism are subjected to pressure and so partially used to intercept the recoil. In the example, the gas discharge ducts 41 run, from the rear end of the bore 33, obliquely outwards, into a compartment which is bounded by the one shoulder of the flange 39, the rear portion of the guide sleeve 19 and by parts of the breech ri-ng 15.

The release mechanism has a construction known per se. In the example selected, a so-called swing breech is illustrated the swing member being designated by 42. The release mechanism further comprises a handle 43, which is likewise known, and a trigger 44. In addition, a lever is provided, with which the opening of the device can be effected, for example for the introduction of the cartridge.

The device constructed according to the invention, for driving pins into masonry or the like, works as follows: The uncocked position of the device is illustrated in FIG. l of the drawing. From this it follows that detonation of the cartridge is not yet possible in this position. This is only the case when the device is transferred into its position of readiness -for detonation, which only occurs when the pin 29 is inserted correctly in the device.

At the commencement of work with the device according to the invention, the pin 29 with the disc 30 placed thereon, is inserted in the muzzle of the lbarrel. When the tip of the pin 29 is placed against the masonry, at that point where the pin is to be driven in, and then pressure is exerted on the device, in the direction of the masonry, then the device is transferred into the position of readiness for detonation, as illustrated in FIG. 2. From this it can be seen that the pin 29, bearing with its tip against the masonry, has now been pushed completely into the interior of the device. -In this position the disc 30, which co-operates with the end face of the front Vguide sleeve 17, entrains the latter in the direction of the rear swing breech. The guide sleeve 17 in turn displaces the rear guide sleeve 18 until this has reached its position of readiness for detonation. It is immediately obvious that, if no pin has been inserted, or if the pin is not provided with a disc, it is impossible for the device to be taken into service. Great safety is achieved as a result.

It can further be seen from FIG. 2 that there is a large gap between the front end face of the piston and the head of the pin 29. This means that longer pins than that illustrated can also be fired with the device according to the invention. When the release mechanism is actuated, with i the individual parts of the device for driving in pins in the position shown in FIG. 2, then the piston 19 is displaced forwards by the high-pressure gases which develop, until it finally impinges, with its front end face, on the head of the pin 29 and drives this into the masonry.

During this forward movement of the piston 19, its shoulder impinges on the widened region 22 of the rfront guide sleeve 17. Thus the first braking stage cornes into action. If the unused energy is still not dissipated in the first braking stage, for example because the pin is driven into soft masonry, such as hollow building blocks, then a second braking stage cornes into action. This is a braking compartment lled with compressible air.

If this braking stage is still not suflicient, co-operation occurs between the annular shoulder 25- and a counter shoulder 26 during the joint forward movement of the piston 19 and guide sleeve 17 (see FIG. 2). The two cooperating shoulders are adapted to one another in such a manner that surface contact is obtained.

In order to obtain further braking, the protective cover 10 can be displaced in relation to the guide sleeve 17 by `an amount which corresponds substantially to the width of the circlip 12. Only after the upper edge of this guide means for the protective cover 10 has come to bear against the upper edge of the circlip, are the other parts of the device used to take up the excess energy.

Thus all the braking stages or only some of them come into action, depending on the material into which a pin has to be driven.

FIG. 3 of the drawings shows an embodiment of a device for driving pins into masonry or the like, which differs somewhat from that shown in FIGS. 1 and 2. In the rst place it should be noted that the front part of the guide sleeve, which is -now designated by 171, corresponds to the embodiment of the guide sleeve 17 already described so that no special comment is needed so far. The rear portion of the @guide sleeve 171 is different in form, i.e., the thickened rear portion 46 of the guide sleeve 171 is constructed in the form of a brake member. The portion 46 is divided into individual segments by slits which run in the longitudinal direction. In the example, two crossed longitudinal slits 48 are provided which divide the rear portion 46 into four segments which are alike in shape. In the normal position, that is to say in the unbraked position, there is a wedge-like clearance 46 between the outer surface of the rear portion 46 of the guide sleeve 171 and the adjacent inner wall of the protective cover 10. This clearance clearly shown in FIG. 4 cannot be seen in FIG. 3 because the braked position is illustrated there. This means that the thickened rear portion 34 of the piston has expanded the part 46 to such an extent that the outer surface thereof is bearing against the inner wall of the protective cover as a result of which braking is effected. In order to facilitate this expansion, the inner surfaces of the segments of the rear portion 46 has a funnel-like recess 49 which co-operates with a shoulder or wedge-shaped portion 50 on the piston. The shoulder 5() is situated at the transition point between the two parts 34 and 35 of the piston. As FIG. 3 of the drawings shows, the transition point has inclined surfaces which are preferably adapted to those of the funnel wall. It should also be added that the rear portion 46 comprises an encircling external Igroove 51 at the base of the slits 48. The primary purpose of this is to provide a weakened cross-section in such a manner that the individual segments can be more easily bent out of their inoperative position and transferred into their operative position, that is to say their braking position.

As already mentioned, the embodiments illustrated are only examples of construction of the invention which is not restricted thereto. Indeed, many other embodiments and applications are possible. For example, the protective cover 10 may have a different form. For example it may be of two-part construction and may possibly be provided with an additional outer cover consisting of a resilient material. Furthermore, both the guide sleeves and the piston may be Igiven a construction other than that illustrated. And finally other pins, known per se, may be used with the device according to the invention.

I claim:

1. A device for driving pins into masonry or the like comprising, in combination, elongated housing means having a front end and a rear end; a firing mechanism connected to said rear end of said housing means; elongated guide sleeve means having a front end and a rear end forming a cartridge holder and being slidably guided in said housing means between a forward inactive position in which said cartridge holder is spaced from said ring mechanism and in which said front end of said guide sleeve means is rearwardly spaced a given distance from said front end of said housing and a rearwardly displaced cocked position ready to cooperate with said firing mechanism; said guide sleeve means being adapted to be engaged by a portion of a pin inserted through said front end thereof while the front end of the pin projects beyond said front end of said housing means in such a manner so that upon exertion of forward pressure on said housing means, said guide sleeve means is moved from said inactive to said cocked position in which said front end of said guide sleeve means is rearwardly spaced from said front end of said housing means a distance greater than said given distance whereby the device may be fired only when after insertion of a pin a rearward pressure is exerted on the latter; and a piston slidably guided in said guide sleeve means forwardly of said cartridge holder and having a free front end spaced from said front end of the guide sleeve means such a distance so that pins of different lengths may be inserted in said guide sleeve means in engagement with said guide sleeve means while the rear end of said pin is still spaced from said free front end of said piston.

2. A device as defined in claim 1, wherein said guide sleeve means comprises a front guide sleeve and a rear guide sleeve having at a front portion thereof adjacent said front guide sleeve a larger inner diameter than thev latter, and wherein said piston has in said portion of said rear guide sleeve a piston portion of a diameter substantially equal to the inner diameter of the latter and a length considerably shorter than that of said rear guide sleeve, and a forwardly extending coaxial elongation of a diameter substantially equal to the inner diameter of said front guide sleeve and extending into the latter to be slidably guided therein.

3. A device as defined in claim 2, wherein said housing means is tubular and wherein a front portion of said housing means has a smaller inner diameter than the rear portion thereof, and wherein said front guide sleeve has a rear portion slidably guided in said rear portion of said housing means and a front portion slidably guided in said front portion of said housing means, said rear portion of said front guide sleeve being in said cocked postion rearwardly spaced from said front portion of said housing means so as to form in said cocked position an enclosed air chamber between the front end of said rear portion of said front guide sleeve and the rear end of said front portion of said housing means.

4. A device as defined in claim 2, wherein said rear guide sleeve has a rear portion of an inner diameter smaller than said diameter of said front portion of said rear guide sleeve so as to form a shoulder at the junction of said rear portion and said front portion of said rear guide sleeve, and at least one passage leading from said shoulder rearwardly and ending at the peripheral outer surface of said rear guide sleeve, and wherein said piston has a rearward extension slidably guided in said rear portion of said rear guide sleeve so that when a charge is detonated in said cartridge holder the combustion gases may escape through said passage after the rear end of said rear extension of said piston has passed said shoulder.

5. A device as defined in claim 3, wherein said front guide sleeve has at the rear end thereof at least two resiliently bendable portions having outer surfaces spaced from the inner surface of said housing means and inner surfaces forming between themselves a funnel-shaped space tapering toward the front end of said front guide sleeve, and wherein said elongation of said piston has a wedge-shaped portion movable into said funnel-shaped space during forward movement of said piston to cooperate with said resiliently bendable portions to press the outer surfaces thereof into engagement with said inner surface of said housing means.

6. A device as defined in claim 3, wherein said tubular housing means comprises a pair of telescoping portions, and means cooperating with said telescoping portions for limiting relative movement thereof so that in said inactive position of said guide sleeve means said front end thereof will always be located rearwardly of said front end of said housing means.

7. A device as defined in claim 1, and including at least one magnet in the region of the front end of said elongated guide' sleeve means and adapted to cooperate with a pin of magnetizable material inserted in said guide sleeve means to hold the pin by magnetic force in said guide sleeve means.

References Cited UNITED STATES PATENTS 2,632,890 3/1953 Tietig 227-10 3,203,609 8/1965 Diehl 227-10 XR 3,239,121 3/1966 Kopf et al. 227-10 3,319,862 5/1967 Neighorn 227-10 WILLIAM W. DYER, I R., Primary Examiner.

R. L. FARRIS, Assistant Examiner.

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