Patent GB-948950-A (GB)
Title: Indexing station for chain conveyor
Inventor: SKINNER NORMAN PHILIP
IPC: B65G47/00
Filed: 1961-05-19
Abstract: 948,950. Overhead conveyers. BAGSHAWE & CO. Ltd. Aug. 15, 1961 [May 19, 1961], No. 18327/61. Heading B7L. An indexing station for a chain conveyer system, of the type in which tracks 11 are provided for load-carrying trolleys driven by driving dogs 26 dependant from a driving chain 21, comprises a plurality of indexing positions, each including a pivoted arm 42 adapted to be raised by a trolley entering the position and supported by the trolley when standing in the position, a stop dog 53 adapted to be raised in the path of the trolley to hold it and operable by the arm 42 of the next forward indexing position, a ramp 49 in each indexing position which is pivoted and is raised without raising the chain to lift a pair of driving dogs 26 to disconnect the drive from the chain to the trolley, the ramp 49 also being operable by the arm 42 of the next forward indexing position, a connecting linkage between each arm of each position and the stop dog and ramp of the last preceding position, the linkages being disposed outside the tracks 11 and alternately on opposite sides of the tracks 11, and a master arm 42 on the outgoing side of the master, i.e. foremost indexing position linked to the stop dog and ramp in the master position and retainable in the raised position by latching means 54 releasable manually or otherwise, an outgoing trolley raising the master arm 42 to reset the latching means. The chain 21 is guided by angle members 20 and is supported by runners 16 fitted with wheels 35 running on a track 14. The runners 16 each carry below the track a block 37 on which the dogs 26 are pivoted at 38, downward movement of the dogs being limited by hangers 39 on the chain and pins 40 on the dogs 26. The trolleys are provided with bogies 30, 31 pivoted on vertical axes on the trolleys and carrying wheels 32 and rollers 33, 34, which rollers engage the spaced vertical central webs of channel members 22 forming the track 11. The dogs 26 engage with an upper platform 23 on the trolleys. The arm 42 at the master indexing position is pivoted at 44 and fixed to a second arm 45, which is pivotably connected to one end of a horizontal rod 46 connected at its other end to a third arm 47 pivoted at 48 and fixed to the ramp 49. The horizontal rod is also connected to a fourth arm 51 pivoted at 52 and fixed to the stop dog 53. The arm 42 is also fixed to a fifth arm 55, one end of which engages with the latch 54 held by a spring 56 and which is released by actuation of a solenoid 57. In its normal position the arm 42 is held raised by the latch 54 and a trolley is stopped at the foremost, i.e. master indexing position, by the dog 53, the ramp 49 being raised to engage with rollers 50, Fig. 4, on the dogs 26 and so raise the dogs clear of the trolleys. A gravity loaded pivoted rear stop 58 is also provided to prevent the trolley from running backwards. If the latch is released the weight of a roller 43 carried by the master arm 42 forces the arm down lowering the stop 53 and the ramp 49, and the rearmost dog 26 of the next arriving pair engages the trolley, the foremost dog 26 riding over the platform 23 by virtue of its chamfered edge 41. As the trolley leaves the master indexing position its platform 23 raises the roller 43 to re-set the latch 54 and set the mechanism to stop the next following trolley. Succeeding indexing positions are provided with the mechanism described above with the exception of the latch 54 and the fifth arm 55, the roller 43 being positioned to be held raised by a trolley stopped at the indexing position next in advance so that a trolley cannot be released from an indexing position until the trolley next in advance has left the next in advance indexing position. As a trolley enters the rearmost indexing position it may engage the arm 68 of a switch 66, which actuates the solenoid 57, so that the foremost trolley will be released, and succeeding trolleys move up one position. To the rear of the last indexing position a safety device is provided to prevent collision between a trolley being advanced and a trolley stationary at the last indexing position. This device comprises a first arm 42a which will be held raised by a trolley standing the last position and will itself raise a horizontal bar 69, through the action of a rod 60 and arms 61 and 63, into the path of an oncoming trolley. The trolley will strike the bar 69 and swing it horizontally to one side to engage a spring arm 65 and operates a switch 64 which stops the chain conveyer motor. Specification 929,867 is referred to.