US2426592A - Device for removal of barbwire entanglements - Google Patents

Description

Sept. 2, 1947. D. BOYCE 2,426,592

- DEVICE FOR REMOVAL OF BARBWIRE ENTANGLEMENTS Filed Oct. 4, 1945 2 Sheet s-Sheet l Sept. 2, 1947. 1.. D. BOYCE DEVICE FOR REMOVAL OF BARBWIRE ENTANGLEMENTS Filed 1945 QIWW I L Eu NARD ILB l Patented Sept. 2, 1947 UNITED DEVICE FOR REMGVAL OF BARBVJIRE ENTANGLEMENTS 3 Claims.

(Granted under the a amended April 30,

The invention described herein may be manu iactured and used by or for the Government for governmental purposes without the payment to me of any royalty thereon.

This invention relates to a device for removing wire entanglements and more particularly barbed wire entanglements used in defensive warfare. Its primary object is to provide a device with which such entanglements can be quickly, expeditiously and completely removed.

The invention contemplates the provision of a projectile adapted to be projected from a gun or mortar, the projectile having attached thereto a cable by which it may be retrieved, the projectile and cable being provided with hooks or grapnels operating upon the strands of the entanglement to tear the entanglement down and remove it when the cable is pulled with appropriate force in a proper direction. Particular attention is paid to the number of hooks employed and the manner of their mounting on the cable.

In the development of the invention, experiment demonstrated that the permanent attachment of the hooks to the cable gave rise to a problem posed by the fact that the jerk incident to launching the projectile invariably broke the cable. To overcome this objection the hooks were mounted slidably' upon the cable permitting the cable to slip through them so that they are picked up gradually, obviating the effects of the sudden jerk occasioned as stated. The leading feature of the invention is not the attachment of a grapnel to a projectile, but the provision of multiple hooks on the cable and manner of mounting to provide a shock absorbing function found by experiment to be essential, the arrangement being novel in the art, so far as I am aware.

A further object of the invention is to provide a device of the character mentioned that will be especially durable and one that may be conveniently and expeditiously operated.

In the drawing illustrating the invention:

Figure 1 is a schematic perspective view of a reel, cable, hook, projectile and mortar assembly, serving to illustrate the invention in a general way.

Figure 2 is a perspective view of the projectile having a fragment of the cable attached.

Figure 3 is a similar view of a fragment of cable with one of the smaller hooks attached.

Figure 4 is an enlarged side elevation of one of the small hooks with a portion of its end area in section, showing the manner of temporarily frictionally securing the hook to the cable.

ct of March 3, 1883, as

Figure 5 is a side elevation of the reel stand.

Figure 6 is a top plan view thereof.

Referring to the drawings, the numeral l designates a projectile, and 2 a mortar from which it may be launched after the usual fashion. The projectile is formed with a rod 3, sufiiciently long to extend beyond the muzzle of the mortar for the pivotal attachment of a clevis i, to which the end of a cable 5, is attached. A suitable distance below the end of the rod it is provided with substantially triangular blades 6, whose bases are welded to the rod, the blade assembly constituting hooks or grapnels which in retrieving the projectile, have their pointed ends positioned to engage the wire strands of the entanglement.

Mounted on the cable, a suitable distance from the rod 3 are other spaced hooks I. These hooks are generally like the hook carried by the projectile but are much smaller. The blades 8 of the hooks are radially arranged upon and welded to a tube 9, mounted frictionally, temporarily, on the cable so as to have a limited sliding movement thereon, important at the moment of launching the projectile.

As shown in Figure 4, one end of the tube is tapered as at ID, and has a tapered external thread H, and is split or kerfed as at l2, for a suitable distance from the end to give the tube a certain degree of resiliency so that when a tapered threaded nut 13, is screwed on the kerfed area, the inner part of the tube will be forced into engagement with the cable, the engagement being such that while the grapnels will be firmly held in proper spaced relation during handling of the device, they will be permitted to slide to a limited extent at the moment of launching the projectile to absorb the shock and prevent undue strain on the cable. The movement of the hooks on the cable need only be slight and movement must not be permitted when the projectile is being retrieved and when the hooks are enmeshed in the entanglements. To prevent this undesired movement the cable will be provided adjacent the end of the tubes with cable clamps I4 which form positive stops for the hooks.

The numeral l5 indicates a stand or support for the cable reel. On the stand are two oppositely disposed identical reel members l6 each comprised of two outer arcuate members I1, outwardly and downwardly curved in easy curves with their lower ends Welded or otherwise attached to the stand, there being inner straight brace members 18 centrally positioned relative to the other members. The lower ends of the brace members are welded or otherwise secured to the stand and their upper ends and the upper portions of all of the members are preferably welded together as shown. These members produce a skeleton structure generally pyramidal in shape from which the cable will be unwound uniformly in the rapid flight-of the projectile. The reel stand is supported at an angle to and adjacent the mortar as shown in Figure 1, so as to assure the unresisted unwinding of the cable.

The small hooks will be placed approximately forty six and ninety six inches respectively, from the large hook on the projectile.

I have shown but one end of the tube provided with a tapered thread but it will be understood that both ends may be made alike, 'although'it is found that a tight initial frictional hold between the cable and the tube is afforded by the structure shown. I I

In operation the projectile is fired with appropriate charge at the range required, and will take its hook andthehooks'on 'the cable into or beyond the entanglements. The home end of the cable will then be =attached'to a tank or other powerful vehicle and pulled. During this pulling movementall the 'polnteden'ds of all the'hooks will clutch the wires-of theentanglem'en'ts, the comparatively heavy '-hook of *the projectile resting onthe gro'und'i'n po'sitionto pick'up'the strands leftby' the smaller hooks-that have preceded.

13A device for reinoving wire entanglements comprising a retrievable projectile adapted to be launched *by suitable launching means, said .projectlle being provided with a forwardly extend- 4 ing rod, a grapnel secured adjacent the end of the rod and adapted to clutch the Wires of the entanglement in the retrieval of the projectile, a cable secured to the rod in advance of the grapnel, a plurality of grapnels frictionally and slida-bly mounted'on the cable and comprising a tube with substantially triangular radially arranged blades having pointed ends extending toward the end of the projectile rod, said tube having a tapered slit end having external tapered threads, a jamb nut having corresponding threads cooperating with the tube threads to force the tube end into frictional contact with the cable to regulate said contact between the tube and cable, and means for limiting the sliding movement between the tube and cable.

2. The invention of claim 1 characterized in that the cable mounted grapnels are substantially smaller than the projectile grapnel.

3. The invention of claim 1 characterized in that the means for limiting the movement of the tube on the cable comprises cable clamps mounted on the cable adjacent said tube.

LEONARD D. BOYCE.

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

UNITED STATES PATENTS Number Name Date 858,009 Meyer et al -June 25, 1907 2,402,? 16 Whitsett June 25,1946

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