Patent GB-774875-A (GB)
Title: Improvements in or relating to sheet separating and feeding machines
IPC: B65H11/00
Filed: 1954-04-08
Abstract: 774,875. Feeding sheets. BACKHOUSE, H. T. April 7, 1955 [April 8, 1954], No. 10400/54. Class 100(1). In apparatus for separating and forwarding sheets from the top of a pile which includes a cpnveyer 68, which takes the sheets from the forwarding mechanism, of the kind embodying endless tapes running over spaced rollers, the conveyer is detachably supported on the framework 60 of the apparatus at positions along the axis of the inner tape roller 67 in a manner which readily permits bodily removal of the conveyer as a unit. As disclosed, the shaft 66 of the roller 67 has bearing bushes located in open forked ends 63, Fig. 5, of brackets 62 secured to a frame cross tube 61, such that this shaft can be readily removed, or the conveyer can be swung upwardly' about the axis of the shaft. The shaft 66 is aligned axially with a pair of stub shafts in the framework and connected thereto by spring-urged collars; one of these collars has a pin-and-slot connection with the shaft 66, and is urged by a spring to engage a dog on a driving sprocket on the corresponding stub shaft, thus providing a readily releasable driving connection to the conveyer 68. Presser rollers 87 are carried by a frame 86 pivoted to the frame 60 at 89. Sheets are separated from the pile at the rear, forwarded in underlapping relationship to some extent by forwarding means at the rear, as described in Specification 427,041, and then pulled forward to the nip of a feed roller 34 and presser wheels 35 by four reciprocating suction grippers 45, Fig. 6, which engage the underside of the front portion of each sheet. Each gripper 45 comprises a bar with a sucker mouth 46 at the top, and one or more nozzles at the end through which compressed air is blown against the pile to assist sheet separation. The bar 45 extends over the shaft 33 of the feed roller 34 and is connected to one arm 48 of a bell-' crank lever of which the other arm 49 has a roller engaging a cam 51 on a rotating shaft 52. The bar is given an upward movement during the first part of its sheetforwarding movement to ensure that a sheet is gripped: this is obtained by shaping the undersurface 53 of the bar which rides over the shaft 33, or by providing a cam on the shaft 33. The sheet-forwarding stroke of the gripper bar 45 is by means of a spring 54 which also ensures that the bar contacts the shaft 33. On the return stroke, the bar engages the pile and jogs any displaced sheets into position. Camoperated valve means control the air blasts and vacuum in the grippers 45. Pile raising and replenishing means substantially as described in Specifications 711,272 and 774,881 may be employed in the apparatus. Sheet-guides. The gap between the feed roller 34 and conveyer roller 67 is bridged by a narrow feed-board 90 which comprises two parts 91, 93 which are telescoped automatically when the conveyer 68 is raised, so that the tapes of the latter are not obstructed. The part 93 is slidable beneath the part 91, against the action of springs 95, Fig. 6, when the conveyer is raised, by means of end cams 101, Fig. 5, each fixed to an outer arm 70 of the conveyer. Each cam engages a pivoted two-armed lever 99 having a slot engaging a pin 100 on the part 93, so that, as the conveyer is raised the cam is rotated about the axis of the shaft 66 to move the part 93 away from the conveyer roller 67. The part 93 can be latched in this position when the conveyer is removed. After sheet smoothers or guides are spaced above the board 90. Specification 427,041 also is referred to.