Patent GB-318904-A (GB)
Title: Improvements in and relating to pile-feeding devices for printing machines
IPC: B65H1/14
Filed: 1928-05-11
Abstract: 318,904. Wright, F. W., Turnbull, D., H., and Mann & Co., Ltd., G. May 11, 1928. Pile supports for sheet-feeds.-A pile-adjusting mechanism for sheet-feeding apparatus for printing-machines comprises means for raising the pile table to its working level by a continuous or uniform movement, and maintaining it at about that level by an intermittent feed. The pile table is supported by four chains 2 passing over sprockets 3, 4, 6; the sprockets 4 are normally clutched by a spring-controlled clutch 9 to a shaft 5, and when the pile table is to be lowered, the clutch 9 is thrown out by a hand lever 84 which also actuates a band brake 89 to control the descent. The shaft 5 is driven by wormgearing operated by bevel wheels 13, 14, capable of operation by a hand-lever 83 having a claw 83<a> which can be made to engage a recess in a spur wheel 16 fixed to the wheel 14. The spur-wheel 16 can be operated by power from a spur-wheel 17 freely mounted on the hub of a dished cam wheel 18, which is rotated by chain gearing from a spur wheel 23 driven by the printing-machine, and serving to rotate the cam 18 once for each cycle of operation. When it is desired to raise the pile table, the wheel 17 is clutched to the cam wheel 18 by means of a pair of pivoted clutch shoes 25, pivoted at 26 and controlled by a spring and a spindle 27 having flat portions 27<a> which permit the shoes to be free of the wheel 18, but which when rotated force the shoes apart so as to engage the wheel. A lever 28 controlled by a cam disc 30, which is freely mounted on the fixed spindle 19 on which the wheel 18 revolves, rotates the spindle 27 so as to clutch the wheel 17 to the wheel 18 when the pile table is to be raised. The cam disc 30 operates the lever 28 only when it is clutched to the hub 18<a> of wheel 18; this clutching is effected by moving the cam 30 axially by means of a freely mounted lever 38 formed with a hub having a helical surface 39 engaging a corresponding fixed helical face 40 fixed to the machine frame. The lever 38 is acted on by a coiled spring 31 tending to move the lever so as to throw out the clutch 25, but a detent 63a on a pawl member engages an abutment on the lever 38 and permits the clutch 25 to be thrown in. In the normal raised position of the pile the detent 63<a> is maintained in position by a finger 62 pivoted to the, member 63 resting on the lower of two pins 65, 66 on a link 67 connected to a lever arm 69<a> of spring- controlled lever-and-link mechanism controlled by a feeler-rod 80 resting on the pile. The finger 62 drops into engagement with a stepped member 61 on a reciprocating link 44 when the pile needs replacement and rotates the pawl member 63 so that the detent 63a releases the lever 38. During normal operation of the machine the lever 38 is operated to declutch the drive by means of a catch 53 mounted on the reciprocating link 44, which is slotted to receive a pin 42 on the lever 38. The catch 53 is moved away from the pin 42 by a stop 54 and is moved back to operative position by a stop 55. The stop 55 is connected by a. link 58 to a lever 59 operated by a counterweighted lever 68. When the pile is low the upper pin 66 on the link 67 operates the lever 68 and causes the stop 55 to be moved out of action, and the clutch remains in operation until the pin has been raised above the lever 68. When this happens, the pile is raised intermittently as described above.