Patent GB-252749-A (GB)
Title: Improvements in and relating to sheet-feeding mechanism for duplicating and other machines
IPC: B65H1/18
Filed: 1924-12-01
Abstract: 252,749. Clatworthy, J., and Gestetner, Ltd., D. Dec. 1, 1924. File tables and supports for sheet feeds; sheet feed-tables ; sheetseparators. - In a sheet-feeding mechanism for duplicating and other machines, of the kind in which the sheets are fed from a pile by reciprocating pads 13, Fig. 4, which buckle the top sheet against a bar 2 resting on the front of the pile, the bar being adapted to oscillate so as to allow the sheet to spring forward, means are provided whereby when the pile is being raised to start the feed, the bar 2 is prevented from rotating under the upward pressure of the pile and so positively arrests the upward movement of the pile. A slotted cam 19 attached to the spindle 1 of the bar 2 engages a pin 20 on a bar 6 reciprocated from a spindle 10 through a cam 8, roller 9, and spring 7 so as to oscillate the bar 2 during the normal working of the machine. A recessed part 20a of the cam slot is engaged by the pin 20 when the bar 2 is bearing on the pile, and serves to prevent the backward rotation of the bar 2 during the initial raising of the pile. The pile table is supported by levers 58, 64 pivoted on spindles 59, 52 respectively so as to have a parallel rising and falling movement. A slotted bracket 66 on the table engages a pin 60 on the end of the lever 58, and an arm 61 on the opposite end of the lever engages a cam 60 on the spindle 52 of the lever 64. The inner end of the table rests on a roller 65 on the lever 64. The spindle 52 is actuated to raise the table when a certain number of sheets have been fed, by a pawl 22, Fig. 2, ratchet wheel 21, and intermediate toothed gearing. A bar 23 reciprocated by a lever 26 from the driving-shaft 10 of the feeding-mechanism carries the pawl 22, and is kept raised so as to prevent engagement of the pawl 22 with the ratchet wheel 21, by a spring-controlled arm 28 during part of its stroke and by a cam 33 on the spindle 1 during the remaining part of its stroke. When raising of the table becomes necessary, the bar 2 turns so far that the cam 33 no longer supports the bar 23 but engages a recess 34 therein, the arm 28 engaging another recess 35 in the bar 23. The pawl 22 then engages the wheel 21 to raise the table until the bar 2 is in such a position that the cam 33 again supports the bar 23. A spring-controlled retaining-pawl 36 is provided for the ratchet wheel 21 and carries an arm 40 which, when the pawl 36 is lifted, serves to lift the pawl 22. The same movement of the retaining-pawl actuates, through bell-crank levers 42, 45, a clutch on the shaft 10 so as to stop the feed mechanism. As the table is being raised, a projecting member 55 on the ratchet wheel engages and carries around with it an arm 54 loosely mounted on the shaft 49 of the ratchet wheel. When the table reaches its highest position, the arm 54 is pushed under the retaining-pawl 36 and the table drops under gravity to its lowest position. As the table falls, the member 55 is carried back by the ratchet wheel 21 until it strikes against the arm 54 so as to allow the retaining- pawl to engage the wheel. A raised portion of the member 55 keeps the pawls 22 lifted until it is desired to restart the feed. The pawl 22 may ride on an untoothed part of the ratchet wheel 21 instead of being lifted by the member 55. The descent of the table can be utilized to operate a switch 57, Fig. 4, so as to stop the supply of current to the driving-motor of the machine. A hand-lever 69 is provided for raising the table into the initial feeding position, and has an extension 70 engaging a pin 71 on an arm 72 connected to the spindle 52. Levers 15 pivoted to the levers 11 carrying the feeding-pads 13 carry a roller 17 caused to bear on the top of the pile by springs 18 so as to maintain a constant pressure on the sheets as they are being fed forward.