Patent GB-636193-A (GB)
Title: Improvements in or relating to machines for periodically disposing material on to a continuously moving conveyor
IPC: B65G47/52
Filed: 1947-01-02
Abstract: 636,193. Liquid-pressure engines. BAKOVENBOUW. VOORHEEN H. P. DEN BOER N. V. Jan. 2, 1947, No. 180. Convention date, March 26, 1946. [Class 69 (ii)] [Also in Group XXX] A device for loading or unloading objects or material onto or from a conveyer is reciprocated, travelling with and at the same speed as the conveyer while loading or unloading and then moving back, the device being reciprocated by a hydraulic cylinder and piston, a control valve or valves for which are controlled both by the motion of the conveyer and by the motion of the device so that the device moves at the same speed as the conveyer during its " forward " movement with the conveyer. A hydraulic cylinder and piston 1, 2 is connected to a transverse bar 4 arranged to reciprocate the loading or unloading device, a slide valve 6 in a valve chest 5 together with a sliding throttle valve 26, 27 controlling the motion of the piston 2. The slide valve 6 is moved by a rack and pinion 7, 8 on a shaft 9 urged in one direction by a spring 13 and urged in the other direction by an electric motor (not shown), controlled by contacts operated by the movement of the piston 2. In the position of the valve 6 shown, pressure liquid from a conduit 19 enters the rear end 16 of the cylinder 1 by way of a port 17 and passage 18, the exhaust from cylinder 1 by way of a port 17 and passage 18, the exhaust from cylinder space 20 passing through a passage 22 and passages in the valve 6 to exhaust through ports 28 in the throttle valve casing 26 and the central chamber 24 of the valve 6 to an exhaust conduit 25. The piston 2 thus moves in a direction to move the loading or unloading device forwardly and at a speed controlled by the throttle valve 27. The stem of the valve 27 is connected by a coupling 31 permitting relative rotation with a spindle 32 having screw-threaded engagement with a rotatable nut 35 held against axial movement and splined engagement with a sleeve 37. A sprocket wheel 36 is rigidly secured to the nut 35 and is connected-by a chain 52 passing round a sprocket 51 keyed to the same shaft 50 as a wheel 49 adapted to bear against the conveyer (see Fig. 2) to be rotated thereby. The shaft 50 is journalled in a carrier 48 rotatable about the spindle 32. During forward movement of the loading or unloading device the carrier 48 is moved to press the wheel 49 against the conveyer by a chain 54 (part only of which is shown in Fig. 2) passing around a sprocket 53 on the shaft 9 and around a sprocket integral with the carrier 48. The chain 54 is biassed by a spring 57, bearing against a seating 58 on a rod 59 attached to the chain and against a fixed seating 56, to move the wheel 49 away from the conveyer. Thus when the shaft 9 is turned to the position corresponding to " forward " movement of the unloading device the wheel 49 is pressed against the conveyer, the sprocket 51, and therefore the nut 35, are rotated, and the spindle 32 and the valve 27 are moved axially to increase the speed of the loading or unloading device. The sleeve 37 carries a pawl-and-ratchet device 41, 45, so as to be rotated in one direction only by a chain 46 passing around sprocket teeth on the pawl-and-ratchet device and connected to a member secured to the bar 4. Thus, during forward movement of the loading or unloading device the sleeve 37, and therefore the spindle 32, is turned to move the spindle 32 and valve 27 axially to decrease the speed of the loading or unloading device. The combination of these two controls causes the loading or unloading device to be moved at the same speed as the conveyer. During the return movement of the device the valve 6 is at the opposite end of its travel from that shown so that the passage 18 is connected to exhaust at 14 and the passage 22 is connected by passages 21 in the valve 6 to a pressure liquid conduit 23. The apparatus may be employed for placing pieces of dough on conveyers, for placing covers on, or removing them from, objects travelling on the conveyer, and for like purposes. A system of relays controlled by the movement of the loading or unloading device and controlling the motor operating the shaft 9 is described.