Improvements in sheet conveyors

996,996. Feeding and delivering sheets; sheet-gripper mechanism. LINOTYPE MACHINERY Ltd. Dec. 13, 1963 [Dec. 14, 1962], No. 47217/62. Headings B6B, B6C and B6H. A sheet gripper comprises co-operating gripper elements carried on an eccentric bush, the latter being supported on a shaft, one gripper element being secured to the bush and the other gripper element being freely mounted thereon, such that rotation of the shaft in one direction opens the gripper element secured to the bush proportionately to the degree of rotation of the shaft, the other gripper element opening proportionately to the degree of eccentricity of the bush, and rotation of the shaft in the opposite direction back to its original position causes the gripper elements to close to grip a sheet such that one and the same gripper element will always close to a set datum line, irrespective of the thickness of the sheet. The sheet conveyer comprises two parallel endless chains having a number of cross-bars 1 secured therebetween. Each crossbar carries a shaft 2 on which one or more grippers are mounted. Each gripper comprises two jaws 3 and 4, mounted on an eccentric bush 6 located on the shaft 2. The jaw 3, bush 6, and shaft 2 are fixed together by a pin 18. The jaw 4 has upstanding side plates 9, which are freely mounted on the bush 6. The jaws are urged towards their gripping position by a compression spring 10. Each jaw has an adjustable stud 15 or 16 by means of which the jaws are set initially to close on to a datum line 14 when there is no sheet therebetween. In operation, the shaft 2 is rotated anticlockwise, as illustrated, by cam means (not shown), to open the jaw 3. The bush 6 moves with the shaft 2 to lift the left-hand end of the jaw 4 and pivot the jaw about the stud 16 as fulcrum. After a sheet has been presented between the jaws, the shaft 2 is returned to its original angular position, whereby the jaw 3 closes on to the datum line 14. The jaw 4 closes simultaneously but is displaced from the datum line by a distance equal to the thickness of the sheet gripped.