ANIMAL STUNNING EQUIPMENT

Abstract: Animal stunning equipment suitable for use with sheep or other small livestock includes a restrainer - conveyor (36) comprising one or more pair of continuous belt or slat con­ veyors having inclined operating surfaces facing each other to define a substantially V-shaped passageway in which an animal can be restrained and conveyed towards automatic stunning means. The stunning means is arranged so that one or more sets of electrodes (30) which are moveable between a stunning position and a withdrawn position, are set at rest to form a barrier in the path of the moving animal to stun the animal immediately it comes into contact with the waiting electrodes. The conveyor is temporarily stopped when the animal contacts the electrodes. After stunning has occured, the electrodes are de-activated and moved to the withdrawn position out of the conveyor path to enable the conveyor to be restarted and eject the stunned animal.

Description: This invention relates to animal stunning equipment. Such equipment is used to stun an animal prior to slaughter. Stunning equipment is known from NL-A-6 702 456 in which transport means is provided by which an animal can be transported towards stunning means along a line of approach, said stunning means including electrodes which are movable between a stunning position and a withdrawn position, whereby an animal may be moved to contact with said electrodes at said stunning position, and moved past said electrodes when said electrodes are at said withdrawn position. According to this proposal the electrodes are positioned in front of the stunning zone above and below the normal position of an animal's head and the electrodes are moved generally vertically into contact with the animal while the latter is stationary at the stunning zone. A problem which arises in the use of such apparatus to stun horned stock is that an electrode can tend to contact a horn, resulting either in poor electrical conductivity or entanglement, or both. This problem is particularly acute when horned rams are to be stunned. The horns of rams are particularly liable to become entangled with vertically or forwardly moving electrodes. A principal object of the present invention is to provide an improved stunning equipment in which problems associated with prior art equipment are avoided or overcome. In accordance with the present invention there is provided stunning apparatus for use with transport means in which an animal can be transported towards stunning means along a line of approach, said stunning means including two sets of electrodes which are movable between a stunning position and a withdrawn position, wherein an animal may be moved into contact with said electrodes when said electrodes are at rest at said stunning position, and moved past said electrodes when said electrodes are at said withdrawn position, characterised in that said sets of electrodes each comprise electrodes elongated to project substantially transversely relative to said line of approach with some of the conductive contacts facing substantially in a direction opposite to the line of approach and some facing substantially transverse to said line of approach, and said sets of electrodes are movable substantially transversely relative to said line of approach between said stunning position and said withdrawn position, so that when said electrodes are at rest at said stunning position, said electrodes form an electrifiable barrier extending across said line of approach, and when said electrodes are at rest at said withdrawn position said animal can be moved past said electrodes without contacting said electrodes. Said sets of electrodes preferably include further elongated electrodes which when said sets of electrodes are at rest at said stunning position, project in a direction generally parallel to said line of approach. The two sets of electrodes preferably each include an elongate array of said electrodes which when said set of electrodes are at rest at said stunning position, are oriented with the long axis of each said array extending substantially vertically and substantially parallel to the other said array. When said equipment is combined with transport means said transport means preferably further includes a restrainer-conveyor comprising one or more pairs of continuous belt or slot conveyors having inclined operating surfaces facing each other, said operating surfaces forming a substantially V-shaped passageway therebetween, said passageway defining said line of approach of said animal. Means is preferably provided to detect contact between said sets of electrodes and an animal moving in said passageway, and means to deactivate movement of said restrainer-conveyor or parts thereof. Said sets of electrodes are preferably mounted for pivotal movement between said stunning position and said withdrawn position, within a plane substantially transverse to said line of approach. Preferably control means is provided which initiates electrification of said sets of electrodes prior to contact of an animal with said electrodes. Centralising guides may be provided adjacent said stunning position adapted to direct said animal or parts thereof into a particular orientation at said stunning position. Said guides may comprise biased hingedly or otherwise flexibly mounted members. A single electrode or set of electrodes may be movable between a rest position and a killing position, wherein said killing position is centrally located in the line of approach of said animal, and wherein said single electrode or set of electrodes is adapted to receive and carry an electrical charge which in normal use is lethal to a contacted animal, and wherein in normal use an aspect of said killing position is that an anal brought to said killing position by said transport means will contact said electrode or set of electrodes with its brisket or thorax region. Nozzles may be associated with said electrodes by which in normal use water or other electrically conductive fluids can be directed onto and around said animal, to improve electrical contact between said electrodes and said animal. A preferred embodiment of the present invention will now be described by way of non-limitative example with reference to the accompanying diagrammatic drawings, in which: Figure 1 is a front perspective view of equipment in accordance with the invention, Figure 2 is a cross-section taken on the line A-A of Figure 1, Figure 3 is a plan view of the right-hand stunning head of Figure 1, Figure 4 is a view taken on the line C-C of Figure 3, Figure 5 is a plan view taken on the line D-D of Figure 1, Figure 6: shows very diagrammatically a sheep about to be carried into contact with the stunning electrodes; Figure 7: shows a view from the front of Figure 6; Figure 8: shows an animal being discharged from the stunning apparatus after the stunning operation has been completed; Figure 9: shows transport apparatus of the present invention in perspective view. The present invention relates broadly to an automatic stunning apparatus suitable for a variety of animal although of course changes in dimension, electrical voltage and the like may be needed as one progresses from the smallest animals up to the largest. In one particular size the apparatus may be used without any major modification or adjustment for a variety of animals including lambs, sheep, goats and pigs. The present invention will now be described by way of example and with reference to the accompanying drawings. The stunning apparatus is shown in Figures 1 and 2 particularly as including a support frame 1 having a pair of transverse guide members 2 between which are shown pivotally mounted by means of pins or bolts 4 a pair of spaced apart legs 3 which by this pivotal mounting are able to rotate in respective arcs as indicated by arrow X-X. The legs 3 are each suitably of an electrically non-conducting material such as a high strength plastics material e.g. "Tivar" (trade mark). A pair of wear strips 5 e.g. of plastics or the like are shown positioned on either side of the transverse guide 2 so as to reduce wear on the legs themselves as they open and close. The top of the left-hand leg 3 is shown in Figure 2 being connected above the frame 1, with a link arm 11 by a clamp assembly 7 with a stub 8, end plate 9 and linkage 10. The link arm 11 is shown pivotally connected with a linkage 12, itself connected by means of a similar clamping assembly 7 with the right-hand leg 3. The linkage 12 is also shown connected, see Figure 3 particularly, with an end plate 13 and via coupling 14 to a cylinder 15, the piston 16 of which is connected by coupling 17 with the end plate 18 connected to the linkage 10 of the left-hand leg 3. This interconnection of the right and left-hand legs 3 may be seen particularly from the plan view shown in Figure 5. Figure 5 also illustrates the assembly at the left-hand side of the frame with the frame member 1, the pair of transverse guide members 2 and the spacing members 25 suitably of plastics or other suitably electrically insulating material. Referring particularly now to Figures 3 and 4 of the accompanying drawings, the plan view of the right-hand stunning head of Figure 1 is shown diagrammatically. The stunning head referenced generally by arrow 26 is seen to comprise a cylindrical pipe 27 with liquid, usually water, connections 28 at each end. Projecting from the pipe 27 are shown a plurality of electrodes 30. The electrical conduction path will be enhanced by the water caused to flow through the nozzles 31. The pipe 27 is shown having at each end thereof end plates 32 which connect the electrode assembly 26 by means of bracket 33 and support bolts 34 with the leg 3. The electrodes 30 are preferably splayed in a horizontal arc of aprroximately 90 o , such that some project in use into the line of approach of an animal to be stunned, others project across the line of approach, and others project at intermediate angles. The spacing of the nozzles and electrodes 30, 31 along the vertical height of the pipe 27 is such as to ensure adequate stunning operation now being described. As seen from Figures 6 and 7 particularly, an animal 35 such as a sheep can be conveyed to the stunning apparatus frame 1 by means of inclined V-belts 36 on either side of the animal 35, holding it off the group with its own weight acting to restrain its movement. The belt 36 is shown as an endless conveyor passing around respective inclined rollers 37 on each side of the frame 1 adjacent the stunning heads 26. Two sets of conveyors are preferably used, although the system might be used with a single pair of conveying belts 26. In the preferred arrangement, as shown particularly in figure 9, a comparatively long 'magazine' conveyor 38 leads onto the entrance of a shorter 'feed' conveyor 36, which carries the animal 35 to the stunning apparatus frame 1. The 'magazine' conveyor 38 runs at a slower speed than the 'feed' conveyor 36 - for example, the conveyor 38 might carry an animal 35 at a speed of 0.7 m/sec while the conveyor 36 carries the animal 35 at a speed of 0.8 m/sec. The difference in speed ensures that animals 35 approaching the stunning apparatus frame 1 are not in contact with each other as the leading animal is stunned. As an animal 35 moves onto the faster conveyor 36 from the end of the slower conveyor 38, it is pulled away from the animals 35 behind it, which are still moving forward at the slower speed of the conveyor 38. In practice a number of animals 35 may be 'stored' on the conveyor 38, and fed one at a time to the stunning apparatus by the faster conveyor 36. A photo-cell detector 39 placed before the entrance of the 'feed' conveyor 36 may be used to control the amount of movement of the 'magazine' conveyor 38, such that when an animal 35 is 'called' and transported to the stunning apparatus, the the 'magazine' conveyor is also activated until the next animal in line is brought to this juncture and registered by the detector 39, whereupon the conveyor 38 stops. For the slaughter of animals to be performed in accordance with the requirement of Halal killing, and also to fit in with contemporary abattoir procedures, it is necessary for no more than 10 seconds to elapse from the time an animal is called, through the stunning process, to sticking of the stunned animal. A two conveyor system, as described above, may make this possible, by having animals held in a 'magazine' ready for quick and efficient transport to the stunning apparatus, where a single conveyor system, into which animals are fed from a pen or run, might take too long. When an animal 35 is called for, the legs 3 will close to the position shown in Figure 1 and 7. The animal will then be conveyed by means of the pair of conveyor belts 36 to the stunning frame 1. Once contact is established between the animal's head and the stunning electrodes 30, the conveyor 36 will be stopped and the stunning current will be given for a prescribed period. Preferably the electric current is running in the electrodes from the moment the legs 3 have closed to the position particularly shown in figures 1 and 7, ie. before the arrival of the animal 35, such that the stunning is initiated at contact of the animal 35 with the stunning electrodes 30, rather than after contact has been made. Preferably also, movement of the conveyor belts 36 is halted by contact of the animal 35 with the stunning electrodes 30. This may be achieved by a small rotational movement of the electrode assembly 26 relative to the bracket 33, under pressure of the animal 35 being run into contact with the electrodes 30, which can be used to activate a limit switch, and thereby stop the conveyor. In this way proper contact between the animal 35 and the electrodes 30 may be ensured before movement of the conveyor will stop. As seen in Figure 8 particularly, once the stunning is completed the legs 3 will open and the conveyor 36 can advance sufficiently to eject the stunned animal out from the frame 1 to be received on the chute 40. To ensure that the electrodes 30 make good physical contact with the animal's head the stunning heads 26 are suitably biased into the animal contact position. To this end springs 41 are shown by way of example connecting the pipes 27 and the legs 3 in Figure 1 although of course other biasing means may be used as required. It is thus seen that in the embodiment of the invention shown, controlled operation of the cylinder 15 or the like would ensure that the stunning heads 26 are in their closed position ready to receive an animal when it arrives at the stunning position. Furthermore, the biasing of the electrode heads 26 into their animal contacting position will ensure good physical contact with the animal's head, and the use of water in conjunction with the stunning will ensure good electrical contact. Furthermore, by mounting the stunning heads 26 on an electrically non-conductive leg 3 suitably of a high strength plastics material, earth leakage current may be prevented. If it is desirable for animals being processed to be killed by the apparatus, rather than simply stunned, it may be preferred to include a special electrode or set of electrodes for the purpose, rather than simply increasing the voltage of the electric current used, or using some other means to achieve this. In such a case the additional electrode is mounted centrally at the base of the frame 1, such that it may move upwards into a killing position simultaneous with closing of the legs 3. The killing position is one which causes the electrode in normal use to be contacted by the brisket or thorax region of an animal brought to the stunning apparatus, such that the current is directed to the heart of the animal, to kill it. A central processing unit or other control equipment may be provided so as to synchronise the opening and closing of the legs 3, the movement of the conveyors 36 and 38 and the initiation and termination of the stunning current. Control of the operation can be fairly simple, as many aspects of the process follow on, one from another, in a simple chain of events which do not require timing. The length of time for which the stunning current is running needs to be preset, and generally may extend for approximately one and a half seconds. The current flow may be monitored, and if found to be insufficient for some reason - possibly an animal's horns prevent proper contact - the conveyor 36 may be reversed a short way, perhaps for a period of one second, and brought forward again to re-establish contact between the animal and the stunning electrodes. With time periods of these lengths, three attempts at stunning may be made on an animal without the slaughtering process being disrupted. Another operation requiring a preset time period is the short run forward by the conveyor 36 after release of a stunned animal by the apparatus, to discharge the animal on the chute 40. The period of the entire cycle may also be automatically controlled with a preset time interval, determined by the speed at which subsequent operations in the slaughtering chain are performed. Preferably however the call for another animal to be stunned is given by an operator. Movement of the conveyors does not need to be timed, as both are activated at once, the conveyor 38 is stopped by sensing of a new animal by the sensor 39, and the conveyor 36 is stopped by contact of an animal with the electrodes 30. Biased centralising head flaps 100 may be provided which assist in ensuring that the head of the animal is presented to the electrodes 26 in the correct position. A further sprung flap (not shown) may also be mounted above flaps 100 to prevent the animal's head being lifted just prior to stunning. Furthermore, front and back limit stops (not shown) may suitably be provided so as to determine the travel of the legs 3 between their open and closed positions.

Claims: Stunning apparatus for use with transport means (36) in which an animal can be transported towards stunning means (26) along a line of approach, said stunning means including two sets of electrodes (30) which are movable between a stunning position and a withdrawn position, wherein an animal may be moved into contact with said electrodes (30) when said electrodes are at rest at said stunning position, and moved past said electrodes when said electrodes are at said withdrawn position, characterised in that said sets of electrodes (30) each comprise electrodes (30) elongated to project substantially transversely relative to said line of approach with some of the conductive contacts facing substantially in a direction opposite to the line of approach and some facing substantially transverse to said line of approach, and said sets of electrodes (30) are movable substantially transversely relative to said line of approach between said stunning position and said withdrawn position, so that when said electrodes are at rest at said stunning position, said electrodes (30) form an electrifiable barrier extending across said line of approach, and when said electrodes (30) are at rest at said withdrawn position said animal can be moved past said electrodes (30) without contacting said electrodes (30). Stunning apparatus as claimed in claim 1, characterised in that said sets of electrodes (30) include further elongated electrodes (30) which when said sets of electrodes (30) are at rest at said stunning position, project in a direction generally parallel to said line of approach. Stunning apparatus as claimed in claim 2 characterised in that the two sets of electrodes (30) each include an elongate array (26) of said electrodes (30) which when said set of electrodes (30) are at rest at said stunning position, are oriented with the long axis of each said array (26) extending substantially vertically and substantially parallel to the other said array (26). Stunning apparatus as claimed in claim 3, in combination with said transport means (36), characterised in that said transport means includes a restrainer - conveyor (36) comprising one or more pairs of continuous belt or slot conveyors having inclined operating surfaces facing each other, said operating surfaces forming a substantially V-shaped passageway therebetween, said passageway defining said line of approach of said animal. Stunning apparatus as claimed in claim 4, characterised by means (26,33) to detect contact between said sets of electrodes (30) and an animal moving in said passageway, and means to deactivate movement of said restrainer-conveyor or parts thereof. Stunning apparatus as claimed in any one of claims 1 to 5, characterised in that said sets of electrodes (30) are mounted for pivotal movement between said stunning position and said withdrawn position, within a plane substantially transverse to said line of approach. Stunning apparatus as claimed in any one of claims 1 to 6, characterised by control means which initiates electrification of said sets of electrodes (30) prior to contact of an animal with said electrodes. Stunning apparatus as claimed in claim 7, further characterised by centralising guides (100) adjacent said stunning position adapted to direct said animal or parts thereof into a particular orientation at said stunning position. Stunning apparatus as claimed in claim 8, wherein said guides (100) comprise biased hingedly or otherwise flexibly mounted members. Stunning apparatus as claimed in claim 9, further characterised by a single electrode (30) or set of electrodes (30) movable between a rest position and a killing position, wherein said killing position is centrally located in the line of approach of said animal, and wherein said single electrode (30) or set of electrodes (30) is adapted to receive and carry an electrical charge which in normal use is lethal to a contacted animal, and wherein in normal use an aspect of said killing position is that an animal brought to said killing position by said transport means will contact said electrode or set of electrodes with its brisket or thorax region. Stunning apparatus as claimed in any one of claims 1 to 10, further characterised by nozzles (31) associated with said electrodes (30), by which in normal use water or other electrically conductive fluids can be directed onto and around said animal, to improve electrical contact between said electrodes (30) and said animal.

Inventors: WINSLOE, RONALD MURLOE
Applicants: ALLIANCE FREEZING COMPANY (SOUTHLAND) LIMITED
Application year: 1986
Main classification: A22B3
IPC codes: A22B3