Patent GB-926247-A (GB)
Title: Sheet stack advance mechanism
IPC: G06K13/10
Filed: 1959-10-14
Abstract: 926,247. Feeding sheets. BURROUGHS CORPORATION. Oct. 14, 1959 [Nov. 7, 1958], No. 34862/59. Class 100 (1). In apparatus for separating sheets or cards sequentially from a stack which can be replenished whilst the apparatus continues in operation, there are two advancing means for pushing the stack towards the separating means, or for pushing two stacks one behind the other, and means is provided whereby the stack advancing function of the rear pusher can be transferred to the forward pusher. As shown, the sheets S<SP>1</SP> rest on edge on a table 16 provided with a front side plate 17, and they are fed continuously over the table towards a moving endless belt 10 which separates them sequentially from the stack. The table 16 is carried on a frame 14 by resilient mountings 19, and is rapidly vibrated by means of an armature 23 on the edge of the table, and an electromagnet 25 secured to the frame 14. Two stack pushers F and R are provided, and these are respectively mounted on carriages 121, 29 which are slidably mounted on shafts 27, 28. The carriage 121 has two sprocket wheels thereon which engage an endless chain 160 driven continuously from a motor-driven shaft 174 and a magnet clutch device 175, 176; one sprocket is an idler, but the other sprocket is associated with a releasable spring clutch device to enable the carriage and pusher F to be driven forwardly by the chain 160. Similarly, the carriage 29 with the pusher R can be driven from an endless chain 161. In operation, assuming a stack S<SP>1</SP>, Fig. 14d, of aligned sheets is in front of the forward pusher F, a button 80 on the rear pusher R is depressed manually to de-clutch its carriage 29 from the chain drive, and the assembly is moved manually to a position where a catch 177, Fig. 2, will hold the assembly in de-clutched condition. A pivoted pusher plate, comprising a vertical blade 146 and handle 151, on the forward pusher F is swung into operative pushing position, causing the carriage 121 to be clutched to the chain drive 160, and the pusher is pushed into contact with the stack S<SP>1</SP>, thus overrunning the spring clutch. The pusher F now advances the stack S<SP>1</SP> through the yielding drive from the motor-driven chain 160. When the stack S<SP>1</SP> is nearly exhausted, a second stack S<SP>11</SP>, Fig. 14d, is placed manually behind it; the rear pusher R is now moved manually away from the catch 177, so that it is clutched to the driving chain 161, and pushed against the second stack S<SP>11</SP>. The vertical blade 146 can now be swung upwardly so that the pusher F is de-clutched from the chain 160, the carriage 121 can be moved back by hand, and the blade 146 can be swung downwardly in between a spring leaf 120a and the front of the pusher plate of the rear pusher R. Thus the combined stacks S<SP>1</SP>, S<SP>11</SP> are fed by both pushers simultaneously, until the rear pusher R is de-clutched by depressing the button 80 and moved back for engagement by the catch 177. For advancing a stack S, Fig. 16b, of unaligned sheets, the forward pusher F is not used and is placed in an inoperative position, coupled to the rear pusher R by swinging the blade 146 of the pusher F into a pocket 112 in the rear pusher. A key 100 on the rear pusher is depressed, whereupon a compressing plate 115 is swung outwardly of the rear pusher plate to compress the stack S at its loose lower region against the separator belt 10. When the last sheet of a stack has been removed, the driving motor M is switched off by the movement of a spring arm 179 through an aperture in the pusher plate of the pusher in use. A warning of near exhaustion of a stack is given by a signal device 181 which is operated by the pusher F closing a switch 183 situated in the path of a bracket 144 on the pusher.