Patent GB-358919-A (GB)
Title: A machine for plucking poultry which is suitable or adaptable for similar uses such as stripping tea plants
IPC: A01D46/04
Filed: 1930-07-14
Abstract: 358,919. Harvesting tea. KINGDON, J. B., Springfield, Stockbridge, Hampshire. July 14, 1930, Nos. 21310 and 35171. [Class 6 (iii).] A machine for plucking poultry or stripping tea plants comprises a rotor having gripping jaws across the direction of travel which are caused to close at the desired point by retardation of the leading jaw. As shown in the Figure, the rotor consists of five radial members 2 to the outer edges of which is secured the rigid member of each gripper. The moving member 5 is hinged at 6 to the rotor and has a projection which is connected by a tension spring 7 to the pivot of the following gripper. To minimize jar on closing the jaws, one or both gripping surfaces are resiliently mounted. As shown, the rigid jaw is a separate bar 11 attached by screws and provided with a step or notch 12. The coacting moving jaw is a block of fibre 13 pivoted to the member 5 at 15 and pressed forward properly to engage the jaw 11 by a leaf spring 16. The pivoted block 13 is retained against the spring 16 by a coil spring 17 on its pivot 15. In operation, the rotor is driven by a spider 4 secured thereto, the shaft 3 which remains stationary carries a cam 10 which engages the tails 9 of the moving jaws and opens them. On release from the cam 10, the moving jaws are closed by the springs 7, the pivotal closing movement being in the opposite direction to the general rotation, thus producing retardation of the leading jaw. When the block 13 encounters the jaw 11, the gripping pressure is increased by toggle action which pushes the block 13 slightly outwards. A guard is placed around the rotor which also serves as a suction casing to facilitate removal of the feathers. The jaws may be closed by centrifugal action or by springs or both. The means for providing a resilient grip of the jaws may be provided on the cam 10, or a rubber pad on one jaw may be used. Alternatively, the resilient gripping edge may be mounted on the pivot of the pivoted jaw. A shock absorber for minimizing the jar of the jaws closing may take the form of two spring-urged inclined surfaces between which a portion of the movable jaw enters just before it reaches the closed portion. In a further modification, jaws on the arms 2 are pivoted to the arms and are backed by compression springs. The moving jaws are positively opened and closed by cams on the normally stationary central shaft, and the pivots are so arranged that, on retarding each of the pivoted jaws to grip the feathers, the gripping edge thereof remains substantially stationary as regards bodily rotation, but moves outwards radially to ensure a good grip on the feathers. The rotor is enclosed in a casing connected to a suction fan casing, the arrangement being such that the fan suction opposes and overcomes, at the aperture in the casing to which the bird is applied, the reverse draught caused by the rotation of the rotor. Air inlet holes in the casing adjacent to the working opening assist this reversal of the air current which is necessary to position the features properly to be gripped by the jaws. The working opening in the casing is adjustable, a wide opening being desirable for the true feathers, and a narrow opening for the pin or stub feathers. Alternatively, the opening may be adjusted at different radial distances from the jaws. The edges of the working aperture are made of celluloid which is sufficiently yielding to prevent injury to the bird. Provision is made for angular adjust. ment of the central shaft and the cams thereon, to effect adjustment of the jaw-closing position. Also, the central shaft may be released to permit its rotation, so that the starting load is diminished.. When the rotor has attained its speed, a spring- pressed pin is released to snap into a locking member to hold the central shaft against further rotation.