AN APPARATUS FOR STUNNING ANIMALS TO BE SLAUGHTERED, SUCH AS PIGS

Abstract: The invention relates to an apparatus for stunning animals to be slaughtered said apparatus comprising two sets of endless conveyor means each defining a substantially V-shaped passage way therebetween said sets being arranged one behind the other, the operating surface of each conveyor comprising plates (4) which are hinged about each other at the edges (5,6) such that no gaps are formed and which may have a curved outer plane (8) at the operating surface which is concentric with the axis (7) of the reversing wheel, the gap (12) between two subsequent conveyors being bridged by rolls (9,10) in line with the operating surfaces of said conveyors.

Description: An apparatus for stunning animals to be slaughtered, such as pigs. The invention relates to an apparatus for stunning animals to be slaughtered, such as pigs, comprising at least one conveyor, said conveyor including two endless conveyor means, said conveyor means being positioned to form a substantially V-shaped passageway therebetween, in which each one of said conveyor means consists of endless chains provided with plates therebetween, said plates being contiguous with respect to each other at the location of the operating surface and said plates having a dimension in the direction of conveyance which corresponds with the length of a link of the chains An apparatus of this type has been described in the Dutch Patent Application 77.05519 laid open to public inspection. In this known apparatus the plates have a rectangular cross section. In the operating surface said plates are quite contiguous with respect to each other but at the location of the reversing wheels said plates provide gaps. At the entrance of each conveyor means these gaps are elosed, whereas said gaps are formed again at the exit. As a result of this the hide, tail or legs of the animal may get caught at the entrance and exit whereas at the location of the transfer from a first conveyor means to a second conveyor means the gaps then formed may entrain the legs into the space in which the conveyor means move in opposite directions whereupon the closing gaps of the following conveyor means may cause serious damages. The object of the invention is to provide for avoiding this problem. According to the invention this object is attained in that said plates are operable to hinge about each other at the edges by means of curved edge portions, said edge portions being concentric with the associated hinge shaft of the chain links.i)ue to the hinge movement of the plates into each other the occurrance of a gaF will be avoided even at the location of the reversing wheels, i.e. the plates will form a closed plane at the location of the reversing wheels. According to the invention it is furthermore preferred that at the location of the entrance of a conveyor or of the conveyors there are provided guide rolls, the axes of said guide rolls being parallel to the operating surfaces of the associated conveyor means and said guide rolls at the periphery thereof touching said operating surfaces. At the entrance said guide rolls provide for a continuous transition from the admission channel to the conveyor means. At the location of the transfer from a first conveyor to a second conveyor said guide rolls form a more or less continuous extension of the operating surface thus lessening the chance that a leg of the animal gets into the transient space while there is but a little chance that the leg of the animal gets caught between the plates of the conveyor means and a guide roil because the rolls may be positioned close to said plates. These guide rolls may be freely rotatable although said rolls may however also be driven, that is to say preferably at such a velocity that the peripheric velocity of said rolls equals the velocity of the preceding conveyor means in order to avoid further conveyance of a pig present at this transfer position when said first means is stopped by too large a supply Preferably the plates are constructed with such a curved outer plane that said plane will be concentric with the axis of the reversing wheel at the location of said wheel. Plates having a flat operating surface will produce a constantly varying distance with respect to the neighbouring guide roll at the location of the reversing wheel. This distance will be small when a hinge shaft is passing whereas the distance will be larger in the center of the plates. Ry constructing the plates with a curvature like described above the distance will remain the same and it becomes possible to operate at such a minimum gap width between the conveyor means and the guide roll that there will be avoided any risk of an animal getting caught with its leg or other part thereof. The invention will now be elucidated further in detail with reference to the drawing showing a diagrammatic cross section of the portions of two conveyor means in succession. The conveyor means shown in the drawing include two chains, i.e. an upper chain and a lower chain each one of said chains having links 1 and hinge shafts 2. Each one of said links possesses a lip 3 on which a plate 4 is mounted. Each one of said plates possesses a front edge 5 having a circular cross section said circular front edge being concentric with the hinge shaft 2, and a rear edge 6 said rear edge covering about a quarter of a circle and being likewise concentric with said shaft 2. At the location of the reversing wheel the axis of which is indicated at 7 the plates are hinging about each other without a gap being formed between said plates. The plates possess a curved operating surface 8 the radius of curvature of which corresponds with the arc of rotation about the reversing wheel so that the operating surface will run concentrically with the axis 7 at the location of the reversing wheel. Between the conveyor means there have been accommodated guide rolls 9 and 10, said guide rolls touching the operating surface 11 of the plates 8 while said guide rolls are at a closed distance with respect to said plates, said distance remaining the same due to the curvature of the operating surface 8 of said plates. In the drawing three rolls have been shown but this number may be chosen arbitrarily. The curvature of the surface of the plates promotes the entrainment of the animals. (claims)

Claims: C L A I N S. 1. 1. An apparatus for stunning animals to be slaughtered, such as pigs, comprising at least one conveyor, said conveyor including two endless conveyor means, said conveyor means being positioned to form a substantially V-shaped passageway therebetween, each one of said conveyor means consisting of endless chains provided with plates therebetween, said plates being contiguous with respect to each other at Qhe location of the operating surface and said plates having a dimension in the direction of conveyance which corresponds with the length of a link of the chains c h a r a c t e r i z e d i n t h a t said plates are operable to hinge about each other at the edges by means of curved edge portions, said edge portions being concentric with the associated hinge shaft of the chain links. 2. The apparatus according to claim 1, c h a r a c t e r i z e d i n t h a t at the location of the entrance of one conveyor or of the conveyors there are provided guide rolls being parallel to operating surfaces of the associated conveyor means and said guide rolls at the periphery thereof touching said operating surfaces. 3. The apparatus according to claim 2 c h a r a c t e ri z e d i n t h a t said rolls are adapted to be driven. 4. The apparatus according to claim 3 comprising two or more conveyors c h a r a c t e r i z e d i n t h a t the peripheric velocity of said rolls equals the velocity of the preceding conveyor means. 5. The apparatus according to anyone of the preceding claims c h a r a c t e r i z e d i n t h a t said plates have a curved outer plane said plane being concentric with the axis of the reversing wheel at the location of said wheel.

Inventors: NIJHUIS, JOHAN WILLEM
Applicants: MACHINEFABRIEK G.J. NIJHUIS B.V.
Application year: 1980
Main classification: B65G17
IPC codes: A22B3, B65G17