Patent GB-751275-A (GB)
Title: Improvements in book signature transfer mechanism
IPC: B65H5/32
Filed: 1954-04-21
Abstract: 751,275. Feeding sheets. SMYTH MANUFACTURING CO. April 21, 1954 [Dec. 2, 1953], No. 11522/54. Class 100 (1). Mechanism for transferring book signatures from an upper position wherein the signatures are located with their sections extending downwardly at opposite sides of a central plane to a lower receiving position comprises two gripper units at opposite sides of the plane, each having an abutment and each having a gripper finger movable relative to the abutment, first cyclically operable means for supporting the gripper units and for moving them between upper gripping positions and lower releasing positions, and second cyclically operable means for relatively moving the fingers of the units to their gripping positions and to their releasing positions. Opening book signatures.- The machine comprises a main frame 30 (Fig. 1), to which is attached a bracket 32. Arms 34, 36 (Figs. 1 and 3), are mounted for pivotal movement about fixed pivot pins 38, 40, carried by the bracket 32, and carry transverse tubular shafts 42, 44, mounted for rotation about their own axes. Rigidly connected with the shafts 42, 44 are arms 46, 48, gripper units 26, 28 being carried by the arms 46, 48 and mounted for pivotal relative movement thereto. Integral with the arms 34, 36 are intermeshing gear segments 54, 56, one of the arms, e.g. the arm 36, having an extension 58 carrying a roller 60 co-operating with a cam groove 62 in a cam 64. A second pair of intermeshing gear segments 74, 76 is integrally formed with levers 70, 72 to which are connected links 84, 86 in turn connected to arms 66, 68 rigidly connected with the shafts 42 and 44. The lever 72 has an extension 78 which carries a roller 80 cooperating with a cam groove 82 in the cam 64. The arrangement is such that on rotation of the cam 64 the grippers 26, 28 are caused to move from the position shown in Fig. 1 to that shown in Fig. 9. A suction control valve 110 operating in timed relation to the cam 64 causes the grippers to grip the signatures in the position shown in Fig. 1 and release them in the position shown in Fig. 9. The machine is adapted to handle signatures having a section at one side wider than that at the other and for this purpose the gripper units are offset vertically from each other. Fig. 1 shows the grippers in position for dealing with signatures having their wider sections at the right and Fig. 15 shows the grippers in position for dealing with signatures having their wider sections at the left. For shifting the grippers from the position shown in Fig. 1 to that shown in Fig. 15, two shafts 132, 134, carried by the arms 46, 48 are provided to which are secured arms 136, 138 which are connected by links 140, 142 to the gripper units 26, 28. The arms 136, 138 co-operate with the links 140, 142 to form toggle devices controlled by springs 144, 146 and stops 148, 150, 152, 154 and actuated by shift dogs 156, 158. The dogs 156, 158 are operated by tripper pins 160, 162, 164, 166, carried on a rockshaft 168, the pins 160, 164 being in longitudinal alignment with each other and the pins 162, 166 being in alignment with each other, the two pairs being circumferentially offset with respect to the shaft 168. Thus, depending on the position of the shaft 168, one rocker pair of trippers engages the dogs 156, 158 so as to shift the grippers from one position to the other. For automatically rocking the shaft 168 after a predetermined number of signatures has been dealt with a ratchet wheel 178, moved one notch each time a signature is dealt with, is provided with pins 182, 184 which operate a lever 174 so that an arm 170 on the shaft 168 is moved between a deep notch and shallow notch in the lever 174 so that the shaft 138 is rotated between the two positions. In an alternative embodiment (Fig. 16), the gripper units 186, 188 are shifted between the two positions for dealing with signatures having their wider sections at the right or left by pneumatic cylinders 194, 196. The cylinders 194, 196 are provided with pistons 202, 204 movable upwardly under air pressure supplied from hoses 198, 200 and downwardly under the action of springs 206, 208. The pistons 202, 204 are connected to the grippers 186, 188. A ratchet wheel (Fig. 17, not shown), is provided which controls a slide valve so as to admit pressure to one gripper unit or the other according as to whether the signatures have their wider sections at the right or left. Gripper mechanism.-The gripper units each comprise a main-housing 92 (Fig. 5), having a chamber 94 for a piston 96. The chamber 94 is closed at one end by a plug 98 connected to the suction pump 110 by a hose 104. The piston 96 is drawn into the chamber 94 when suction is applied and is moved in the opposite direction by a spring 100. The piston 96 is formed with a rack meshing with a pinion 106 which also meshes with a segmental pinion 108 carrying a movable gripping finger 90. The finger 90 co-operates with a fixed finger 88 formed on the main housing so as to grip the signatures A when suction is applied through the hose 104.