US2812655A - Grenade fuse tester fixture - Google Patents

Description

Nov. 12, 1957 F. J. CURRAN 2,812,655

GRENADE FUSE TESTER FIXTURE Filed June 22. 1955 INVENTOR.

United fitates Patent Office 2,812,655 Patented Nov. 12, 1957 GRENADE FUSE TESTER FIXTURE Frank J. Curran, Downers Grove, Ill. Application June 22, 1955, Serial No. 517,249 4 Claims. (Cl. 73-35) The present invention relates generally to a hand grenade fuse, but more particularly to a simple, inexpensive and long-lasting grenade fuse tester fixture which will withstand the explosion or blast hundreds of times over the fixtures heretofore used.

It has been the practice heretofore in the manufacture of fuses for hand grenades to make a certain percentage of fuse tests in relation to the number of fuses manufactured and in this connection, sleeves which were required to embrace the fuse in these tests were made from pipe, cut off and machined to the correct length, thereby requiring toolmakers time and other labor and in addition required continuous replacements, all of which added up to excessive cost and expense to supply these sleeves and make these tests. The sleeve in these instances supports the fuse therein and surrounds the detonator of the fuse so as to completely confine the explosion on impact when the supporting sleeve and fuse is dropped for the test. In this connection, the blast or explosion caused by these tests would blow out and destroy the sleeves after two or three tests, requiring replaced machined sleeves, which entailed considerable expense.

It is, therefore, one of the primary objects of the present invention to not only overcome the disadvantages above pointed out, but to also provide an improved fuse testing fixture which will partly confine the blast of the explosion but permit the major portion of the explosion or blast to blow out between spaced apart studs or screws mounted in suitably spaced apart apertures in the test member. With the present invention, when necessary, new conventional screws or studs which are readily available, may be quickly substituted for the old ones by the operator without the loss of time or the use of a toolmaker to furnish the replaced part. The screws or studs of the present invention surround the detonator of the fuse and guide the positioning of the fuse in mounting the same in the supporting structure.

A further object of the invention is to provide a novel and improved fuse testing fixture which not only provides an economical and easy way to replace the mutilated parts, but also provides commercially available replacement parts which can be purchased at a low cost in comparison with the cost of machined pipe sleeves.

A still further object of the invention is to provide a novel and improved construction of a fuse testing drop fixture in which replaceable sets of screws or studs can withstand approximately from 250 to 300 tests, after which the worn out or damaged screws or studs can be readily replaced by new ones.

A still further object of the invention is to provide a fuse testing drop fixture in which the body thereof is provided with additional sets of apertures in the fixture member so that the screws or studs may be placed in these new apertures if for any reason the previously used holes in the fixture are mutilated.

These and other objects are accomplished by providing a construction and an arrangement of the various parts in the manner hereinafter described pointed out in the appended claims.

Referring to the drawings:

Fig. 1 is a side elevation view of my improved dro test fixture for hand grenade fuses showing the manner in which the same is supported in a grenade fuse testing machine or device;

Fig. 2 is a cross sectional View taken on the line 2--2 in Fig. 1; and

Fig; 3 is a top plan view of the same.

In order to disclose a more complete understanding of my improved grenade fuse testing fixture, I have shown the same in connection with a conventional fuse testing machine or device, only a fragmentary portion'of which is shown in the drawings, for supporting the fuse and the fuse testing fixture in position in the device and the means for withdrawing the pin and releasing the lever synchronously with dropping the fuse and fuse fixture.

and particularly This conventional fuse testing machine comprises briefly, a main frame member 10, which is supported on a base or stand (not shown). Secured to an extended portion 11 of the main frame 16 is a cup-shaped member 12. This cup 12 is cylindrical in shape and is adapted to support centrally therein my improved fixture and the attache-d fuse as clearly shown in Figs. 1, 2 and 3 of the drawings. This cup 12 has a vertically extending slot in the side wall thereof, as shown at 13, for the accommodation of a cap lever of the fuse in the manner hereinafter described. My improved fixture is supported in the cup 12 by a reciprocable trigger member 14 which has its outer edge conically curved, as shown at 15, to engage the conical surface of my improved fixture. The device 10 is provided With a fuse pin pulling member 16 which is provided with a hook, as shown at 17, on the outer end thereof to engage the ring of the fuse. The trigger member 14 and the puller member iii are electrically actuated through a solenoid and controlled by a micro switch (not shown) so that they can be controlled at a remote distance from the device as a whole in the manner well understood in the art.

My improved fuse testing fixture comprises a member in the form of a frustum of a cone, generally indicated by the reference character 12%. The member in has a conical surface, as shown at 19, which terminates in a fiat bottom 2a. The conical surface 18 terminates in a relatively short cylindrical portion 21 which fits loosely into the circular recess of the cup 3.2, the upper portion of the member 18 and the flat top 21. The member 18 is also provided with a centrally located conical recess 22. This recess 2.2 terminates in an axially threaded bore 23 in which the fuse is adapted to be mounted therein in threaded engagement. The top surface 21 of the fixture member 1'8 is provided with a set of vertically dispose-d equally spaced apart threaded bores 24. 0nd set of similarly equally spaced apart threaded bores 25 are provided in the member 18 which are adapted to have mounted therein threaded screws 2a The threaded apertures 24 are spaced apart approximately one hundred twenty degrees fro-m each other and the threaded apertures 25 are similarly spaced apart, but each of these sets of apertures are spaced relatively a slight distance from one another as clearly shown in Fig. 3 of the drawings. The purpose of this arrangement is to permit three threaded screws to be equally spaced so that the periphery or head of the screws engage the inner wall of the cup in a relatively loose fashion for maintaining and guiding the fixture in position, prior to releasing it from the device. It is also a further advantage of these spaced apart screws to partially confine the explosive blast at the same time permit the major portion of the blast or explosion to freely pass between the upright screws A secand thereby reduce to a minimum the destructive effect both on the fixture 18 and the screws. Should the blast distort the screws, a replaced one may be inserted in threaded engagement with the fixture 18 with a minimum effort or expense. The addition of threaded apertures in the fixture 18 permits their use in the event that threads of a previous usedaperture has become mutilated so that the fixture can be continued to be used for additional tests.

The grenade fuse here shown is of a conventional type and comprises a head 27 provided with externally threaded studs 28 formed integrally therewith which is adapted to be mounted in threaded engagement with the threaded aperture 23 of :the fixture 18. Formed integrally with the stud 23 is a sleeve extension 29. Mounted in the sleeve 29 is a detonator member 30. Pivotally and removably mounted on two laterally extending pinlike lugs 31 formed integrally with the head 27 is a conventional quick detachable release lever 32. The release lever 32 is retained in position on the head 27 by a removable cotter pin 33 which extends through aligned apertures in the parallel and oppositely disposed ears 34 of the lever 32 and an aperture in the head 27. Secured to the eye of the cotter pin 33 is the usual ring 35 which is adapted to be engaged by the hook 17 of the puller member 16. Obviously, upon the energization of the electrically controlled apparatus of the device 10, the trigger member 14 and the puller member 16 is actuated in synchronized movement to pull the pin 33, remove the lever 32 and drop the fixture 18, thus set in operation the firing of the cap and the fuse in the detonator simultaneously with the dropping of the fixture to test the firing of the fuse.

In the function of operation of my improved grenade fuse testing fixture, it will readily be seen that upon the explosion or blast of the fuse, the same will not be confined as in the fixtures heretofore used, but will be permitted to rapidly expand between the screws without any serious mutilation of the fixture 18 or the screws 26 and if replacement, such as additional screws, be required, they are readily available and easily inserted for any distorted or mutilated ones, thereby reducing to a minimum both the time, expense and effort for continuous uninterrupted use of the testing device.

In the above description I have described the use of threaded screws in the fixture 18. However, it will bev understood that simple studs or pins may be inserted in these apertures with transverse smaller pins extending through the fixtures 18 and the stud retaining them therein if such a construction is so desired.

While in the above specification I have described one embodiment which my invention may assume in practice, it will, of course, be understood that the same is capable of modification and that such modification may be made without departing from the spirit and scope of the invention as expressed in the following claims.

What I claim as my invention and desire to secure by Letters Patent is:

1. In a drop testing device for fuse detonators, a fixed support, a fixture releasably mounted in said support for holding a detonator, the explosive part of said detonator extending upwardly of said fixture, and a plurality of studs on said fixture spaced around the explosive portion of said detonator for guiding said fixture in said support and confining the explosion of the detonator when said fixture is dropped.

2. In a drop testing device for fuse detonators, .a fixed support, a fixture releasably mounted in said support for holding a detonator, the explosive part of said detonator extending upwardly of said fixture, a plurality of removable studs on said fixture spaced around the explosive portion of said detonator for guiding said fixture in said support and confining the explosion of the detonator when said fixture is dropped.

3. In a drop testing device for fuse detonators, a fixed support, a fixture releasably mounted in said support for holding a detonator, the explosive part of said detonator extending upwardly of said fixture, and a plurality of uniformly spaced apart replaceable studs on said fixture spaced from and parallel to the explosive portion of said detonator for guiding said fixture and confining the explosion of the detonator when said fixture is dropped.

4. In a drop testing device for fuse detonator, :a fixed support, a fixture releasably retained on said support for holding a detonator, the explosive part of said detonator extending in a direction away from said fixture, and a plurality of studs on said fixture spaced around the explosive portion of said detonator for confining the explosion of the detonator when said fixture is dropped.

References Cited in the file of this patent UNITED STATES PATENTS 2,368,018 Groth et a1. Jan. 23, 1945 2,448,203 Africano Aug. 31, 1948 2,476,479 Brack July 19, 1949 2,478,659 Jackson et al Aug. 9, 1949 2,777,323 Street Jan. 15, 1957

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