Patent GB-911385-A (GB)
Title: Letter feeding and presentation apparatus for letter sorting machines
Inventor: OSBORN HOWARD
IPC: B65H5/00
Filed: 1958-07-21
Abstract: 911,385. Feeding sheets &c. THRISSELL ENGINEERING CO. Ltd. July 21, 1959 [July 21, 1958], No. 23328/58. Class 100 (1). [Also in Group XXX] A letter feeder for a letter-sorting machine comprises a suction device 3 which separates a letter from the top of a pile in a magazine 1 and presents it to feed rollers 5, 6 for delivery to a compartment for reading by an operator, the suction device and rotatable forwarding means arranged in the said compartment being driven by a common, cyclically variable, speed driving means which includes a four-bar kinematic chain. The letters L, Fig. 1, are stacked in the magazine 1 which has a base consisting of an intermittently moving belt 2, and a front plate 4. The suction device 3 is fixed by a bent tube 88 to a block 81 having guide rollers 80 running in a cam track 181, the block being connected by a rod 79 to a crank 77 secured to a gear-wheel 75. The gearwheel 75 is driven at variable speed so that the suction device 3, guided by the cam track 1.81, separates a letter and presents it to the rollers 5, 6 at slow speed, and then returns at a greater speed. The suction device 3 comprises sucker 83, which grasps the top letter, and bender members 84 arranged on either side of the sucker which are hollow and are expanded under atmospheric pressure to bend a letter held by the sucker to ensure that only one letter is separated at a time. The members 84 are contracted, just before the letter is presented to the rollers 5, 6, by suction applied to the interiors thereof. The suction pipes 85, 86 leading from the sucker and benders are connected to a fixed valve block 87, Fig. 3, which co-operates with a second block 27 which is rotated from the main drive as described below. The letters are delivered by the rollers 5, 6, and a belt 9 and rollers 7, 8 down into a shoot 10 to rest edgewise on rotating worms 11 and rollers 14, 15 which feed them towards a pair of rotating separator discs 12. Each disc 12 has a bent portion 13 which engages behind a letter and feeds it to the front of the discs where it is read by an operator, who manipulates the sorting machine. Driving mechanism.-The main shaft 22 is driven from a shaft 20 through a flexible coupling 21, and this drives the apparatus through a one-revolution clutch 23. The driven part of the clutch 23, Fig. 3, is secured to a sleeve 24 which is secured to the valve block 27, and has a gear 26 in mesh with a gear 37 secured to a stub shaft 38. A crank-pin on the gear 37 is coupled by a link 41 to a crank-pin on a member 42 which is fixed to a journalled shaft 44. The shaft 44 has secured thereto at its other end a member 46 similar to the member 42, which is coupled by a crankpin to a link 48 and that link is connected to a disc 49 by another crank-pin. The parts 37- 49 jointly constitute a compound four-bar kinematic chain. The disc 49 is fixed to a shaft 51 on which is secured a gear 152 which engages and drives a gear 36 and a sprocket 35 therewith. The gear 36 drives the gear 75 to actuate the sucker device 3, and the sprocket 35 drives mechanism as described in Specification 909,472. The shaft 51 also drives, through a safety ballclutch 54 and gears 53, 55, a shaft 56 from which the discs 12 are driven; and a second shaft 60, driven by sprockets from the shaft 51, drives the worms 11. The rollers 14, 15 which centralize the letters are driven continuously from the shaft 22 by chain and sprockets 72-74. Specifications 768,504, 849,421, 854,543 and 876,739 also are referred to.