GB2074836A - Devices for use in the humane slaughtering of animals - Google Patents

Abstract

A device of the captive bolt type is described. The bolt 9 has a penetrating extremity 16, which may be parallel-sided or tapered backed by an abutment flange 15. In use, the penetrating extremity pierces the skull of the animal, but much of the surplus kinetic energy of the bolt is dissipated by engagement of the abutment flange with the animal's head, thereby reducing the force to which the barrel 2 is subjected in arresting the bolt. <IMAGE>

Description

SPECIFICATION Devices for use in the humane slaughtering of animals This invention relates to devices for use in the humane slaughtering of animals and of the kind in which a captive bolt is housed substantially within a barrel and is adapted to be driven lengthwise of the barrel by an explosive force applied thereto.

Such a device will hereinafter be referred to as a 'device of the captive bolt type'.

The end of the bolt which strikes the animals head is often provided with a 'knocker head', an enlargement which applies a blow to the animal's skull without penetrating the skull, but it is usually preferred to employ a bolt having a plain cylindrical end which is adapted to penetrate the animals skull.

Since the bolt is a captive one it is necessary to absorb in some way the energy imparted to the bolt by the explosive force. In the case of the knocker head substantially all of the energy is absorbed by the animals skull, but in the case of the penetrating head the energy cannot be fully absorbed by the animal's brain and is partially absorbed by the barrel of the device. It is common practice to provide the device with several annular resilient buffers mounted on the bolt for engagement by an enlargement on the bolt.

The aim of the invention is to provide a device of the captive bolt type having the advantage of a penetrating action but which has a reduced loading of the barrel in use.

According to the invention in a device of the captive bolt type the operative end of the bolt for application to an animal's head comprises a penetrating extremity of relatively small transverse width backed by a non-penetrating abutment portion of relatively large transverse width adapted for engagement with the animal's head around a hole produced in the skull by the penetrating extremity.

With such a device the kinetic energy still associated with the bolt after the penetration of the animal's skull by the extremity of the bolt is absorbed substantially by the animal's skull when the abutment portion engages with the animal's head. This makes it possible to employ a lighter barrel since the barrel is not employed to absorb the excess kinetic energy. Alternatively, if a barrel of the usual dimensions is employed the life of the barrel should be increased.

Although it might be possible to omit the rubber buffers from such a device, it is preferred to provide at least one resilient buffer to arrest the bolt without causing damage to the barrel in the event that the device is inadvertently fired in the air. Since such a buffer will not be subjected to continuous use, it will not normally require replacing.

The penetrating extremity of the bolt may be of plain cylindrical shape as is usual for bolt heads of the penetrating kind, but it may instead be provided with a taper to ease removal of the penetrating end from the skull.

The taper is preferably in the range 10 to 5 .

The invention will now be further described, by way of example only, with reference to the accompanying drawings in which: Figure 1 is a side elevation of a captive bolt device in accordance with the invention with the barrel assembly shown in longitudinal crosssection; and Figure 2is a side elevation of the front end of a modified bolt for use in the device of Figure 1.

Referring to Figure 1, a barrel assembly 1 comprises a cylindrical main barrel 2 rigidly carried by a stock 3 shown un-sectioned, and threadedly received at its front end within a counterbore 4' at the rear end of a barrel extension sleeve 4 of larger internal bore 8 than that of main barrel 2. An abutment washer 5 is trapped between the extremity 6 of main barrel 2 and a step 7 between counterbore 4' and bore 8.

A bolt 9, shown in the fully retracted position, comprises a main stem 10 which extends slidably through abutment washer 5 and a pair of annular rubber buffers 11, a front end part 12 for applying a blow to an animal's head, and an enlarged rear end portion 1 3 in the form of a piston which is slidable in the bore 2' of main barrel 2 and is adapted to receive the explosive force produced by detonation of a cartridge 14. The manner in which the cartridge is detonated is not relevant to the present invention, and will not therefore be described.

In order to permit assembly of the abutment washer 5 and buffers 11 to the stem 10 they are each formed with a radial slot, not shown, of a width equal to the diameter of stem 10.

At its front end the stem 10 is flared outwardly into a disc-shaped abutment portion 1 5 of front end part 12 from which depends a forwardly directed penetrating extremity 1 6 of plain cylindrical shape and of a diameter which is substantially less than that of the abutment portion 1 5. Abutment portion 1 5 is slidable in bore 8, and in the fully retracted position shown engages with the abutment washer 5. Penetrating portion 1 6 is provided in known manner with a rearwardly extending bore 16', indicated in dotted outline, provided with a frusto-conical counterbore 17 so as to define an annular blade 18 which assists in piercing a skull.

In use, the firing mechanism, not shown, for the cartridge 14 is activated by releasing the usual safety device, the front end of the barrel assembly 1 is applied to the animals head, and a trigger mechanism is operated by the user to cause the cartridge 1 4 to be fired in known manner to apply an explosive force to piston 1 3 and drive the bolt forwards relative to the barrel 2.

The extremity 16 will pierce the animal's skull to enter the brain, but whilst the piston 1 3 < is still substantially spaced from the buffers 11 the front face 1 9 of the abutment portion 1 5 will come into engagement with the animal's head, and the impact of abutment portion against the animals head will arrest the bolt and absorb the kinetic energy of the bolt which remains after the penetration process.

Thus the animal's head absorbs substantially all of the kinetic energy of the bolt, and the life of the barrel will be increased, since the barrel will not normally be required to absorb the bolts energy.

Alternatively, a barrel of reduced strength may be employed. The rubber buffers 11 are provided, however, to arrest the bolt in conventional manner by engagement of the piston 13 with the rear buffer in the event that the device is inadvertently fired in air. The barrel 2 is made sufficiently strong to absorb the bolt's energy on such occasions, but since it will not be subjected to stressing on each firing it can still be made of lighter construction.

Also, since the buffers 11 are not continuously in use they will not normally require replacing.

Since the stem 10 of the bolt is not exposed, the buffers 11 will not become contaminated in use to the same extent as occurs with conventional penetration-type devices, where the penetrating extremity of the bolt engages with the buffers in the retracted position of the bolt.

Figure 2 shows a modified front end portion of the bolt which differs from that of Figure 1 in that the penetrating extremity 1 6 has a taper, i.e. it is of frusto-conical shape with a core angle of 2 , the narrower end being at the front. This assists in the removal of the penetrating extremity from the skull.

Claims (6)

1. A device of the captive bolt type, as hereinbefore defined, in which the operative end of the bolt for application to an animal's head comprises a penetrating extremity of relatively small transverse width backed by a nonpenetrating abutment portion of relatively large transverse width adapted for engagement with the animal's head around a hole produced in the skull by the penetrating extremity.

2. A device as claimed in Claim 1 in which the penetrating extremity is tapered so as to have its smallest transverse dimension at its free end.

3. A device as claimed in Claim 2 in which the penetrating extremity is of frusto-conical shape, the cone angle lying in the range 10 to 5 .

4. A device as claimed in any of the preceding claims comprising at least one elastomeric buffer arranged to assist in arresting the bolt after it has been shot.

5. A device for use in the humane slaughtering of animals substantially as described with reference to Figure 1 of the accompanying drawings.

6. A device as claimed in Claim 5 but modified substantially as described with reference to Figure 2 of the accompanying drawings.