Patent GB-940194-A (GB)
Title: Trolley transfer means
IPC: B65G47/61
Filed: 1962-02-28
Abstract: 940,194. Conveyer systems. RICHARDS-WILCOX MANUFACTURING CO. Feb. 28, 1962 [March 31, 1961], No. 7872/62. Heading B7L. A device for transferring a trolley from a first to a second track in an overhead conveyer system comprises a trolley guide for guiding the trolley from the first track to the second track and a flexible transfer member e.g. a chain engageable with the trolley and movable along a transfer guide parallel to the trolley guide under the control of a power operating device which is arranged to be actuated in response to the advance of the trolley and which is arranged to effect reciprocation of the trolley along the trolley guide. The conveyer system described comprises a main track for the trolleys (one of which is shown in Fig. 5 and is provided with pairs of running wheels 22 pivotally mounted on a load bar 12 with a work supporting eye bolt 14, the trolleys being guided by rollers 24 rotatable on vertical axes) parallel to which runs a power track supporting a driving chain with dogs which engage with pusher bars 29 extending laterally on both sides of each trolley. The trolleys run in a box-section track with a central slot in the bottom wall (cf. the track B in Fig. 7), and storage tracks are provided branching from the main track and eventually joining up with it again, the trolleys moving in the storage tracks under the action of gravity, no parallel power track being provided. The switch means which control the entry of the trolleys to the storage tracks from the main track may be controlled by a sensing device in each storage track which does not allow entry of a trolley if the storage track is full, or in addition each trolley may be provided with projecting pins 26, Fig. 5, which engage switches and operate the switch means if the pins are at the correct height so that each trolley may be " coded " to enter a particular storage track, if the track is able to accommodate it. Fig. 2 shows the main track with the load track LT for the trolleys and its associated power track PT. A branch track B is also shown with its associated switch means. The trolley guide from the load track LT to the branch track B is formed with a central slot as in the tracks themselves and on one side of the slot is formed of members 39, 40 and 41 and on the other side by a switch point 44 and a guide plate 45. The operation of the switch point 44 is described in detail in Specification 903,780 and is effected by an air cylinder C1 Parallel with the slot in the trolley guide are mounted two parallel slider plates 57, 58 between which slides a chain 60 forming the transfer member, the chain also being supported by the slider plates, cf. Fig. 7. The chain is shown in Fig. 10 and is provided at end with a depending pawl 76, pivotally mounted thereon, the pawl having rollers 80 to engage with the pusher bar 29 of a trolley. The pawl is able to pass over the pusher bar of trolley when the chain is moved from the storage track B to the load track LT but when moving in the opposite direction it engages the pusher bar and moves the trolley. The other end of the chain 60 is connected to a piston rod 49 of an air cylinder C2, Fig. 2, mounted alongside the load track LT. A solenoid operated valve SV controls the air cylinders C1, C2 and normally the switch point is disposed to prevent entry of a trolley to the storage track and the chain 60 is fully extended between its slider plates, the pawl 76 then being adjacent the storage track B. A trolley passing along the load track LT, if " coded " to enter the storage track B will operate switches LS1, LS2, Fig. 2, and this serves to open the switch points 44 and to retract the chain 60 to the position shown in Fig. 2. The trolley enters the trolley guide and is pushed along by the dogs on the power chain under the pawl 76 on the chain 60. The trolley guide curves away from the load track LT so that at this point the pusher bar 29 is no longer in the path of the power track PT. The trolley actuates a switch LS2 which closes the points 44 and moves the chain back towards the storage B causing the trolley to be pushed into the track B. A switch LS4 on the storage track B senses when the track is full and prevents entry of further trolleys. The air cylinder C2 may alternatively be arranged adjacent the track B when the pawl 76 on the chain 60 is reversed and the normal position for the chain is the fully retracted position and the transfer chain 60 may also be used at the points where the storage tracks rejoin the main track in a manner similar to the above. Specification 590,384 also is referred to.