Patent GB-712031-A (GB)
Title: Improvements in or relating to apparatus for separating stacked flat articles
Inventor: BRIERLEY NORMAN
IPC: B65H3/08
Filed: 1950-01-18
Abstract: 712,031. Feeding sheets. POSTMASTER-GENERAL. July 10, 1951 [Jan. 18, 1950], No. 1342/50. Class 100 (1). [Also in Group XL(b)] In apparatus for separating flat articles, such as letters, from the top of an inclined stack by a pneumatic separator, the articles rest edgewise against an upwardlyextending supporting member which moves up with the platform of the stack, whereby sliding friction between the articles and the support is eliminated. Sheet-separators.-Letters in a stack, placed in a three-sided trough 4, are separated from the top by a collapsable sucker 15 carried by a rigid hollow tube 14 which is secured in a block 16. The block 16 is fixed between a pair of arms 17 provided with anti-friction bearings 18, 19 at each end which run in cam-shaped slots 20, 20a. The lower bearings 18 are coaxial with the gudgeon pin 24 of a connecting-rod 25 on a crank 26 driven through gearing and an electromagnetic clutch 12 by a motor 11. As the crank 26 rotates, the sucker 15, due to the cam slots 20, 20a, follows a path shown in chain-dot lines, Fig. 6, to present a letter to rotating snatch rollers 34, 35 which complete the sheet separation. The sucker arm 14 is connected by tubing 28 to a rotary valve 27 (not shown), secured to the end of the crank shaft 26, which is connected to the low pressure side of a motor driven air pump 29. The valve 27 cuts off suction to the sucker 15 at the moment the latter is seized by the rollers 34, 35. As shown, the sucker 15 comprises a rubber body secured between a metal &c. pad 32 and an upper metal plate 30, and the pad is curved at the end remote from the rollers 34, 35 to facilitate withdrawal of " window " envelopes from the sucker. Separation of letters is facilitated by blasts of air from nozzles in the trough 4. The clutch 12 of the motor 11 could be operated by an electric pulse received as the result of the disposal of a separated letter. Pile tables.-The letters are stacked in a threesided trough 4 which is mounted on the frame 1 at about 30 degrees to the vertical. They rest on a movable platform 6, and their rear edges abut a flexible band 7 attached to the rear end of the platform : the upper end of the band is wound up on a spring-loaded roller 9 as the platform rises. The platform 6 is connected, releasably, to a lead screw 54 by a split nut 53. Lever means 63, 65, 66 arranged beneath the platform enable the sections of the nut 53 to be disengaged from the screw 54 so that the platform can be lowered or adjusted uickly. The lead screw 54 is driven through a friction clutch by a motor 57 to raise the platform 6 and keep the top of the stack of letters at a constant height. The motor 57 is controlled by a relay adapted to be energized by a photoelectric cell 69 (not shown). A beam of light from a source at the opposite side of the letter stack impinges on the cell. On the removal of the top letter or letters by the sucker 15, the beam of light can strike the cell, and thus the stack is raised until the top letters interrupt the beam. Two or more stacks arranged side-by-side may feed into a common conveyer.