Patent GB-880170-A (GB)
Title: Endless conveyors
IPC: B65G17/06
Filed: 1958-01-30
Abstract: 880,170. Endless articulated plate conveyers. KNAUST, H., and KRITTER, U. VON. Jan. 30, 1958, No. 3126/58. Class 78 (1). In an endless conveyer composed of a series of troughed plates 14, the forward end of each of which overlaps the rear end of an adjacent plate, each plate carries two axles 16, 17 provided at their ends with rollers 18, 14 respectively, the axle 16 being carried between enlarged links 20 of a pair of endless chains 11, while the axle 17 is free so that the rollers 14 can follow the contour of a pair of rail tracks 21 provided at one or more positions along the upper run of the conveyer and comprising dipped portions 29. Below each dipped portion 29 is a hopper 30 which receives material from the plates as the rollers 14 enter the dip, causing the plates to tilt and discharge their load. In order to determine which of a number of such discharge stations will be operative to discharge material, bridge rails 31 are positioned over each dipped portion 29 to leave gaps at each end, the gaps at the forward ends being normally closed by fingers 33 freely pivoted to the bridge rails at 34, while the gaps at the rearward ends are closable by switching rails 32 pivoted at 36 to the rails 21 and movable between positions in which they lead the rollers 14 on to either the bridge rails 31 or the dipped portions 29, respectively. The switch rails are operated through toggle links 38 by rotation of a shaft 39 which is effected either manually by a chain 44 or by operation of a reversible electric motor 41. The motor 41 is controlled by an operator at a control point and also by a track switch 51, Fig. 4. The track switch is disposed immediately in advance of a discharge station and comprises an operating lever 50 pivoted at 57 and having a head 52 adapted to be positioned in the path of the rollers 19 when the discharge station is in use, and retracted as shown when the discharge station is out of use. Projection and retraction of the head 52 is effected through a link 58 and lever 62 by an hydraulic piston and cylinder 65. The lever 62 is semi-floating, being pivoted at 66 to the operating lever 67 of a switch 68. The arrangement is such that when the piston and cylinder 65 is operated, the lever 62 pivots about the pivot 66 to raise or lower the head 52, while if the head 52, when in raised position, is struck by a passing roller 19 the lever 62 pivots about its connection 63 with the piston and cylinder 65 and operates the switch 68. The piston and cylinder is operated in opposite directions by respective valves controlled by solenoids energized through a relay 77, Fig. 5, while the motor 41 is operated in forward and reverse directions through a reversing switch operated by solenoids 41a, 41b. In operation, the operator depresses button 75 once to cause the appropriate station to discharge, and depresses it again to cause discharge to cease. When button 75 is depressed the piston and cylinder 65 is operated via the relay 77, to raise the head 52 into the path of rollers 19. Upon the head 52 being struck by a roller 19 the switch 68 is operated, closing contacts 78 which complete a circuit through contacts 3/4 of the relay 77 to the solenoid 41a which causes the motor 41 to raise the switching rails 32 to cause discharge to cease. When the rails 32 are fully raised a switch 80 operated by a cam on the shaft 39 breaks the motor control circuit and lights an indicator 81 while a second switch 82 also controlled by the cam is closed to prepare a circuit for the solenoid 41b and to extinguish an indicator 71. These operations occur in reverse when the button 75 is depressed again so that the rails 32 are again lowered to cause discharge of material. Should the rails 32 jam in an intermediate position for longer than a predetermined time a delay relay 83 is operated through contacts of the switches 80, 82 and this relay breaks the circuit of the conveyer driving motor. In a modification, Fig. 7, discharge is effected on the lower run of the conveyer, the dipped portions 29 being provided in lower rails 87, while the upper run is supported by two pairs of rails 84, 85 respectively engaging the rollers 19, 18. At each pair of reversing wheels 12, 12a of the conveyer the rails 85 are discontinued while the rails 84 pass around the wheels and are overlapped by curved sections 88 of the lower rails 87.