Patent GB-888735-A (GB)
Title: Improvements in or relating to conveyor systems
IPC: B65G19/02
Filed: 1958-05-21
Abstract: 888,735. Conveyer systems. RICHARDSWILCOX MANUFACTURING CO. May 21, 1958 [June 20, 1957], No. 16363/58. Class 104 (2). In a conveyer system in which at least one track switch is arranged for diverting a load carrier from a branch track to a main load track or vice versa the track switch includes a motor arranged to move a section of the main load track into a diverted position of alignment with the branch track on approach of a load carrier and back into a normal position of alignment with the main load track after the load carrier has passed the switch and the motor also serves to propel the load carrier through the switch. In the system shown in Fig. 1, load carriers are normally propelled around a closed loop load track LT by a pusher chain running on a power track PT arranged in side-by-side relationship. Load carriers are diverted on to branch tracks B, C or D by a switch G and a sensing device E assumes a control position if the particular branch track B, C or D is full to prevent further load carriers being fed thereto. The load carriers pass from one end of the branch track B, C or D by gravity and each track is provided with a speed-control device BR to slow down or to speed up the movement of the load carriers along the sloping branch tracks. Switches H are provided at the end of each branch track B, C or D to divert the load carriers on to the main track ML. The load carriers, Figs. 2 and 3, comprise a bar 35, from which the load is suspended by an eye-bolt 37 or similar device, provided at each end with buffers 39 and the load bar 35 is hung from wheels 48 which run on tracks LT of inverted U-shaped section. Guide wheels 53 are also provided. The load carriers are driven by a transverse pusher bar 61 engaged by spring-loaded pivotally mounted pusher dogs, Fig. 4 (not shown), depending from a wheel mounted chain running in an inverted U-shaped track PT. Selector pins 55, 56 are mounted on the arms of a U-shape member 57 carried by a load bar 35. The diverting switch, Fig. 7, provided at the entrance end of each branch track B, C or D has a switch section comprising two articulated tongue sections 101, 102 which establish connection between the load track LT or the load track LT and the curved section 103 forming part of a branch track B, C or D. The free end of the section 102 is suspended by a bracket 108 fixed to the top thereof and having a flange 109 which slides along an arcuate guiding surface 111 formed on a V-shaped frame 112 supported on a sub-frame 119 and the tracks LT and 103. The sections 101, 102 are moved from one operative position to the other by a rod 131 passing through and bearing by means of springs 134, 135 on opposite sides of an eye 132 pivotally attached to the bracket 108. The other end of the rod 131 is pivotally connected to a rotatable throw bar 151, Fig. 8. The bar 151 has a T-shaped clutch dog 172 pivotally mounted on its underside and on the end opposite to that to which the rod 131 is connected. The clutch dog 172 is movable between stop lugs 176, 177, Fig. 10, provided on the underside of the bar 151. Projecting downwards from one end of the cross-bar of the T-shaped clutch dog 172 is a driving lug 178 which can be engaged by one of a number of square-headed driving dogs 171 mounted on a driving disc 170 driven in a counter-clockwise direction by a motor 142, Fig. 7, through a chain 149 and sprocket 148. The motor 142 also drives a chain 141 by means of a sprocket 147. Selector switches F1, F2, Fig. 7, cooperating with the selector pins 55, 56 are provided at the entrance to the switch G. A limit switch F3 is provided on the track 103 of the branch track B, C or D and a control limit switch F4 actuated by a movement of the track section 101, 102 is mounted on the frame 112. The switch operates as follows. The selector pins 55, 56 of an approaching load carrier actuates the switches F1, F2 to set up a current which by-passes open contacts of the switch F4 to energize a magnetic starter coil to connect the motor 142 to the mains and at the same time set up a circuit through closed contacts of the switch F4 to energize a solenoid 186, Fig. 8. The motor 142 now drives the chain 141 and rotates the disc 170 and the solenoid 186 actuates a latch 182 to release the dog clutch 172. A clutch dog spring 174, Fig. 10, pivots the clutch dog 172 into a position in which the lug 178 is engaged by one of the lugs 171 on the rotating disc 170 and the bar 151 is rotated counter-clockwise through a 180 degrees to move the track section 101, 102 from the straight through position to the curved position in alignment with the branch track 103 and thus release a plunger 215 of the switch F4 to reverse the contacts therein to establish a circuit through the magnetic starter coil. The bar 151 on being rotated through 180 degrees moves the clutch dog 172 into abutment with a dog latch 181 which pivots the dog clutch 172 against the spring 174 to move the lug 178 out of driving engagement with the lug 171, thus allowing the disc 170 to continue to rotate and the switch sections 101, 102 to remain in the deflected position. The load carrier is now pushed along the deflected track section 101, 102 by the dogs on the chain running on the track PT until the cross-beam 61 moves out of engagement with such chain and the drive is then taken up by pins 197 carried by links 196 on the chain 141 which pushes the load carrier on to the gravity section 103 of the branch tracks B, C or D. The load carrier now actuates the switch F3 to energize a solenoid 185 to trip the dog latch 181, thus releasing the clutch dog 172. The clutch dog 172 is now pivoted into a position by the spring 174 where it is engaged by a lug 171 so that the rotating disc 170 now rotates the bar 151 counter-clockwise through a 180 degrees to move the sections 101, 102 to the straightthrough position. When the bar 151 reaches a 180 degrees position the dog clutch 172 engages the dog latch 182 and the dog clutch 172 is moved against a spring 174 out of driving engagement with the lugs 171. The plunger 215 of the switch F4 is depressed once the sections 101, 102 reach the straight through position and the contacts of the switch F4 are returned to their original positions to break the circuit to the magnetic starting coil and stop the motor 142. The switches H at the exit ends of the branch tracks B, C or D, Fig. 1, are similar to the switches G described above, except that at each switch, Fig. 14 (not shown), on the branch track is actuated by a cam provided on the chain 141 to move the sections 101, 102 to the curved position only if a load carrier is present on the branch track and to release such load carriers one at a time only if the driving dogs on the main tracks are able to accept a load carrier. In addition, a further limit or control switch provided adjacent to the sprocket wheel 147 is actuated by the driving pin link 197 to energize the solenoid 185 and thus initiate the operation of the mechanism to move the sections 101, 102 from the curved to the straight through position. In the arrangement shown in Fig. 2, the selector pins 55, 56 are arranged at fixed coded heights on the flanges 57 to actuate the appropriate selector switches F1, F2. In a modification, Fig. 21, the pins 55a, 56a are adjustable in height for effecting different feeding switch selections or station selections. In this modification the pins 55a, 56a are mounted on rotatable discs 255, 255<SP>1</SP> which are held in the adjusted position by a plunger 261, operated by spring-loaded push button 265, entering an aperture in the flanges 57<SP>1</SP> and one of a number of holes in the disc 255 or 2551. In a further modification, Fig. 24 (not shown), the pins 55, 56 are mounted on a T-shaped slideway, provided on the flanges 57, and are held in the adjusted position by a spring-loaded ball. In yet a further modification shown in Figs. 26 and 27 the selector pins 55, 56 can be automatically reset to a predetermined initial position when the load-carrier reaches a predetermined point on the system. In this arrangement the pins 55c, 56c pass through arcuate slots 297, 297<SP>1</SP> in a U-shaped member 294, secured to the load arm 35, and are mounted on the ends of U-shaped frames 296, 296<SP>1</SP> pivotally mounted on the U-shaped member 294. The pins are upwardly biased by springs 298, 298<SP>1</SP> and are held in the selected position by downwardly-sloping notches 304, 304<SP>1</SP> formed on segments 301, 301<SP>1</SP> pivotally mounted on the U-shaped member 294. The segments 301, 301<SP>1</SP> are held in engagement with the pins 55c, 56c by springs 306. The upward position of the pins 55c or 56c can be manually effected by moving the segments 301, 301<SP>1</SP> outwardly by means of handles 307, 307<SP>1</SP>. The pins 55c, 56c can also be pulled manually downwards over the notches 304, 304<SP>1</SP>. If it is desired to automatically restore the pins 55c, 56c, to a normal raised position deflecting arms 308, 308<SP>1</SP> on passing under a tripping rail, are moved outwardly to allow the pins to snap back to the normal elevated position. The speed control device BR, Fig. 28 (not shown), provided on the branch lines B, C and C comprise a pair of chain-driven parallel rubber discs the peripheries of which engage oppositely projecting arms of each pusher bar 61 to slow down or speed up the load carriers. If required, more than one speed-control device BR may be provided along each branch track. The sensing device E provided on each branch track after each switch G comprises, Fig. 29 (not shown), a pair of triangular members which depend from switches into the path of loadcarrier bars 61 travelling on the branch tracks so as to block the circuit to the feeding switches F associated with the particular switch G and thus prevent further load carriers entering the branch track. Specification 590,384 is referred to.