Patent GB-752829-A (GB)
Title: Machine for feeding envelopes and similar workpieces individually from a stack to a printing mechanism
Inventor: SKOW ROSS ERIC
IPC: B65H3/10
Filed: 1954-04-06
Abstract: 752,829. Sheet-feeding apparatus. WALBERT MACHINE CO. April 6, 1954, No. 10113/54. Class 100 (1). Sheet separators; pile tables.-Apparatus for feeding workpieces to a printing mechanism 138 comprises a suction cylinder 42 (Fig. 5) adapted for rotation below a support for a stack of workpieces so that a marginal edge of the lowermost workpiece is in bearing contact with the cylinder, and a contact wheel 78 mounted for co-opeiation with the cylinder 42 adjacent the stack of workpieces is in a position to bend a withdrawn workpiece slightly towards guides below the level of the stack. The apparatus comprises a frame 7 (Fig. 1) including a cross bar 8 and side bars 9, 10 supported by bracket portions 11. Also provided is a cross-bar 12 on which are mounted stationary parallel bars 13, 14 through which extends a rod 16 on which are pivotally mounted stack adjusting bars 17, 18, adapted to be raised and lowered by adjusting screws 19 and nuts 20 (Fig. 2). Vertical standards 24 are adjustably carried on the frame 7 by foot portions 25 having slots 26 through which fastening devices 27 are extended, the standards 24 being adjusted to bear against the edges of a pile of sheets. Adjustable loop-shaped fingers 29 are provided to engage the underside of the bottom sheet. The stack support also includes vertical members 31, 32 that engage the forward side of the stack and which are supported by a cross bar 34. The lower ends 36 of the members 31, 32 curve forwardly so as to stagger the lower sheets of the stack. Also carried on the cross bar 34 is a member 37 having a forwardly curved lower end 38 to which is attached a rubber strip 39 having a forwardly curved end 40 adapted to bear upon the suction cylinder 42. The member 37 may be adjusted vertically by an adjusting screw 49 mounted on the cross bar and threaded through a sliding block 43 to which the member 37 is attached. In addition to the standards 24 a standard 53 is provided to which is pivoted an adjustable support 51 provided with an inclined foot 59 which engages the stack of sheets to relieve the pressure on the lowermost sheets. The suction cylinder 42 is fixed on a transverse driven shaft 59 and is provided with diametrically opposed suction ports 60, 61, connected with channels 62, 63 which successively connect with an arcuate port in a valve plate mounted coaxially of the shaft 59 and anchored against rotation thereon. The periphery of the cylinder 42 has circumferential grooves 75, 76 to receive the forward ends 15 of the bars 13, 14. The cylinder 42 carries the forward edge of a sheet towards a conveyer 77 by the aid of pressure wheels 78 mounted on a shaft 79. Sheet forwarders: pusher feeds for single sheets.-The conveyer 77 comprises endless chains 82, 83, running over sprockets 84, 85, and carrying a plurality of pusher pins 95 for engaging the rear edges of the sheets. The sheets are forwarded over a guideway formed by longitudinal guides 100, 101 (Fig. 4 ) supported on bars 106, 107, and which co-operate with pairs of spaced longitudinal rails 102, 1021. Guides 104, 105 are provided to support the upper runs of the chains 82, 83. Adjustably supported on the cross bars 106, 107 are angle-shaped rails 111,111<SP>1</SP> having inwardly extending flanges 112, 113 to support the marginal edges of the sheets, and vertical flanges 114, 115 to retain the sheets in alignment while they are advanced. The sheets are retained in contact with the guides by upper guide rails 116, 117 ... 119 adjustably supported on transverse rods 120, 121, carried at their ends in longitudinal bars 124, 125 pivoted on a cross-rod 126. The opposite ends 127 of the bars 124, 125 are adjustably supported by set-screws 128<SP>1</SP> on the bar 106 (Fig. 11). Guide rollers 129, 130 co-operating with pressure rollers or wheels 132, 133 are provided for supporting the rear edges of the sheets in position to be engaged by the pins 95. Sheet registering devices.-To ensure correct positioning of the sheets prior to entry between the feed rollers 144, 145 of the printing machine 138 the angle-shaped rail 111<SP>1</SP> is arranged at a slight angle with respect to the conveyer chains so that the sheets are urged against the angleshaped rail 111. Sheet smoothers.-Brushes 191, 192 for ensuring contact of the sheets with the pin 95 are attached to the shafts 120, 121. Similar devices 195, 196 are carried by arms 1951, 1961 pivoted on a bar 197 carried at its ends on the cross rods 120, 121 (Fig. 12). Faulty feed control devices.-The bar 197 (Fig. 12) carries switches 198, 198<SP>1</SP> which have operating arms 199 that bear on a bar 200 that has its ends adjustably mounted on stems 201, 202 carrying a runner 203 directly over the path of the envelopes. In the event of sheets piling up on the conveyer the runner 203, stems 201, 202 and bar 200 are lifted to operate the switches 198, 198<SP>1</SP> to stop the machine. In the case of a sheet not being fed a contact arm 207 contacts a plate 208 to operate a switch 206 and stop the machine. To prevent operation of the switch 206 in the intervals between the sheets the circuit to the arm 207 is broken by a cam mounted on any operating shaft of the machine working in timed relation with the conveyer chains and co-operating with a pair of fixed switches. When large sheets are to be fed one of the pair of fixed switches is disconnected from the circuit and every other pin 95 removed from the conveyer chains.