US2549993A - Breechblock for explosively actuated fastening tools - Google Patents

Description

Aprii 24, 1951 .s. A. TEMPLE BREECHBLOCK FOR EXPLOSIVELY ACTUATED FASTENING TOOLS Filed July 19, 1946 V D m V v%/0\ EW? IN VEN TOR. .STQNLE 4. TEMPLE ATTORNEYS Patented Apr. 24, 195i orrics BREECHBLOCK FOR EXPLOSIVELY ACTUATED FASTENING TOOLS Application July 19, 1946, Serial No. 684,935

7 1 Claim. 147) This invention relates to the insertion of fasteners. It has to do particularly with explosive propelled fastenings for attaching mountings in a masonry construction.

Heretofore one way of inserting or aflixing fastenings in walls, floors, ceilings, etc., of concrete or the like has involved forming a hole in the body of concrete, generally by means of a star drill and hammer, after which an expanding bolt is inserted and expanded to grip the sides of the hole. This is a tedious and expensive procedure.

The mounting of fastenings in metal plates by means of an explosive charge has been known for a. considerable time. Evidently it was assumed by workers in the art that such a method could not be employed with respect to concrete and like bodies upon the theory that such a body would be shattered by the force of the impact. I have discovered that such isnot the fact, and that on the contrary if the explosive charge be properly selected for a given set of conditions the fastening will be tightly embedded in the concrete body, and to the depth desired. Since concrete is not fluid in character and cannot flow as can metal, and hence cannot be bulged out by a projectile, it is natural to assume that it must necessarily be shattered when a projectile is fired into it. What actually happens is not known with certainty, but I believe that great heat is generated instantaneously as the projectile penetrates the concrete body and that under this heat, combined with the heavy pressure exerted by the explosive charge, the concrete immediately surroundin the projectile is rendered plastic, its porosity eliminated, and the material compacted to make room for the projectile as its pointed end enters the body. The resulting grip of the compacted concrete upon the projectile is exceedingly strong, being much superior in this respect to the grip of an expansion bolt.

Asalient object of the invention relates to the improvement of a breech block for use in explosively actuated fastener driving tools in whichthe breech block construction is such as to permit the breech block to be inserted either end foremost in the breech end of the barrel of the tool.

Other objects and features of novelty will appear as I proceed with the description of those embodiments of the invention which, for the purposes of the present application, I have illus trated in the accompanying drawing, in which Fig. 1 is a side View, partly in section, of a projectile embedded part way in a concrete wall, the enlarged and threaded head of the projectile extending outwardly from the wall.

Fig. 2 is a side view of the same projectile in its original condition before being placed in a. tool and fired.

Fig. 3 is a similar view of a projectile with an. internally threaded head in its original unfired. condition.

Fig. 4 is a side view partly in section of theprojectile of Fig. 3 after it has been fired from a tool and is embedded in a masonry body, with a threaded eye-bolt mounted in the embedded pro-- jectile.

Fig. 5 is a side View, partly in section of an unthreaded projectile fired into a concrete wall. through one flange of an angle iron for securing: the latter to the wall, and

Fig. 6 is a view, principally in central longi-- tudinal section, of a tool for firing any of the: illustrated projectiles.

Referring now to the drawing, II] is the barrel. of a tool designed for firing the projectiles illustrated. Barrel I0 is provided with a bore II and. a counterbore I2, the latter running out at theinner end of the barrel. In the counterbore I 2 I mount a breech block I3 provided with a bore to fit a blank cartridge I4 of standard size. Both.

.ends of the breech block I3 have counterbores I5 in order that the flange I6 of the cartridge may be inserted flush with the end of the breech block. This arrangement permits the block to be inserted in the barrel either end foremost.

The externally threaded projectile of Fig. 2 and the internally threaded projectile of Fig. 3 are provided at their rear ends with outwardly extending annular flanges i! and I? respectively which are adapted to bear against the shoulder formed at the junction of the bores II and I2 of the tool. With this flange in place between this shoulder and the breech block the latter stands flush with the inner end of barrel It.

The head I8 of the externally threaded projectile has an undercut I9 extending a substantial distance along the projectile in front of the flange I1, and forwardly of this undercut the balance 'of the head I8 is threaded as shown at 20. The

external diameter of the threaded portion 20 is such that it fits slidably within the bore H of the tool and serves to guide the projectile in its forward travel through the bore from the position of Fig. 6 to the flared end 2! of the bore. When the cartridge I i is exploded pressure builds up behind the projectile until it reaches a value suflicient to sever the flange II, after which the projectile is driven out of the tool, the severed flange [1 remaining temporarily in the tool. The flange is severed or broken away from the projectile close to the undercut I9 because its circle of minimum length occurs there, but the break is not necessarily a clean and smooth one. Usually a rough edge 22 is left on the projectile, as indicated in Fig. 1. This edge however is of less diameter than the root diameter of the threads of threaded portion 20, and hence offers no obstruction to the application of a nut or other internally threaded member to be attached to the embedded projectile.

The internally threaded projectile of Fig. 3 has a smooth head 24 of the same diameter as the external diameter of the threaded portion 20 of the projectile of Fig. 2. Head 24 therefore fits slidably Within the bore ll of thetoo'l and flange ll engages the shoulder between bores l and l l. When this projectile is in place in the tool and the cartridge behind it is exploded flange I1 is sheared off quite cleanly along aouter surface of the metal object. When attach- 1 ment of the metal object to the body'is the only requirement the head of the projectile need not be threaded. In other cases where it i desired to provide a smooth surface on' a rough wall and to fasten some object thereto, a metal plate such as 25 of Fig. 1 may be held againstthe'wall and an externally threaded projectile fired therethrough into the wall, as shown in that figure.

Fig. 4 illustrates one use of an internally threaded projectile. Here the cartridge selected is one having a charge of such strength that the entire projectile is forced into the wall flush with the exterior surface thereof. projectile is driven into the wall only until the head thereof engages the exterior surface. either event the internal threads 35 may receive an externally threaded stud of any desired type,

as for example an eye-bolt 3i, and this bolt may be held against turning by a lock nut 32. Objects of various kind may be hung from such asupport.

In Fig. 5 I have shown the invention applied to the problem of securing an angle iron 80 to a concrete or other masonry wall. In this case the head iii of the projectile is not threaded. The angle iron is held against the wall by a helper and the operator fires the projetcile through a flange of the angle iron, the projectile coming to a stop when the shoulder 62 of the projectile head 5| strikes the angle iron. Structural steel of other cross-sections may of course be secured to a wall, floor or ceiling by the same means.

The tool for firing these projectiles, other than 'With respect to the parts abovedescribed, may be ofany desired construction. That herein illustrated comprises a carrier 35 that is removably threaded at 36 to the rear end of barrel l0, and is provided with an end surface 3'! that abuts against the barrel and provide a backing for breech block I3 and 'thefla'nged end of cartridge 14.- In order to facilitate the connection and disconnection of the-barrel Ill and carrier 35,

these parts are knurled as indicated at 3B and 39.

In addition the outer end of barrel Ill may be provided withspann'erwrench holes 40. When a In other cases the discharged cartridge is to be removed and the tool reloaded, the operator separates barrel II] from carrier 35 by unscrewing it. He then shakes loose and drops out of the barrel the breech block i3, the exploded cartridge I4 and the severed projectile flange IT or H", puts a new projectile into the bore ll until the flange H or ll thereof engages the shoulder at the junction of the two bores II and i2, then inserts the breach block l3 either end foremost and finally puts a new cartridge into the breech block, after which the barrel I0 is again threaded into the carrier 35.

As shown herein carrier 35 has a bore 42, 43', in which is mounted a firing pin 44 that is normally held 111* retracted position by a coil spring 45. A sleeve 46 provided with a, handle 41 is mounted to slide upon carrier 35, and may be" held against rotation by a pin 48 mounted in the carrier cooperating with a slot 49 in the sleeve. A centrally disposed plunger 50 rigid with the sleeve 46 is pushed vigorously forward by one hand of the operator whose other hand grasps the barrel Ii], thereby causing the firing pin to set' off the cartridge. Coil spring 52 normally holds the sleeve 46 in retracted position. Theforwardend of the barrel may be provided with a'conical guard 55 for c'uttingoff flash from the cartridge when the tool is discharged.

It will be appreciated that projectiles of the kinds illustrated, and others having heads of the proper diameter to fit within the bore of the tool, may be embedded in masonry bodiesvery'rapidly as compared with the conventional means of mounting fastenings in such bodies. The disconformed with considerable dispatch, and the mounting of the projectile in the masonry body is then of course instantaneous. Consequently various brackets, plates, fastenings .and the like may be secured to buildings of concrete or other masonry with rapidity and at small cost. The projectiles are'formed of steel and are preferably pointed, as shown.

Having thus described my invention, I claim:

In a tool of the character described, a barrel having a bore for guiding the projectile, said barrel having acounterbore adapted to receive a flange on a, projectile, a breech blockof uniform external diameter slidably mounted in said counterborefor engagement with said flange, said breech block having a central bore for the reception of a flanged blank cartridge .and'being counterbored at both ends for the reception of the cartridge flange, whereby said breech block may be insertedeither end first, backing means for the outer end'of said breech block, and means for firing said cartridge.

STANLEY A. TEMPLE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS

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