Patent GB-641490-A (GB)
Title: Improvements in duplicating machines
IPC: B41L11/10
Filed: 1947-12-04
Abstract: 641,490. Copying documents. FORD, R. M. Dec. 4, 1947, No. 26733. [Classes 100 (i) and 100 (ii)] A duplicating machine comprises a flat printing table, a presser parallel to and spaced from the table, means for moving one of these members towards and away from the other, means for carrying a master sheet so that part of it is disposed between the presser and the printing table, a carriage having means for gripping a copy sheet, means for moving the carriage into and out of a position in which the copy sheet is between the presser and the printing table, and means adapted to moisten the copy sheet during the inward movement of the carriage. The machine comprises a frame 12, Figs. 2 and 4, on which is mounted a feed table 10, Figs. 2 and 8, in an opening in which is a longitudinal channel bar 16 having a rectangular slot in which is mounted an impression table comprising a strip 40 of rubber or the like mounted on a vertically slidable and upwardlyspring-urged plate 41. Mounted at one end on the table 10 or the bar 16 is a bracket 48 having pins 120 on which is mounted by means of toggle levers 110, 112 a slide 115 in an angle portion of which are secured by pins 123 a plurality of plastic strips 122 forming the presser. The bracket 48 carries cross-plates 50, 51, in bearings in which are removably mounted rollers 52, 53 on which is wound a master sheet 73. The master sheet is wound from the roll 53 to the roll 52, passing under the presser and between two pairs of rods 74, 78, the rods 78 having short lengths of rubber tube 77 and the rods 74 knurled flanges 76 to grip the master sheet. The rods 78 are carried at one end on levers pivoted to the plate 50, and at the other end pass through slots 81 in the plate 51 and are secured to bell-crank levers 86 pivoted at 83 and spring-loaded over-centre, so that by manually moving the levers 86 the rods 78 move to release the sheet 73 and remain apart from the rods 74 until the levers 86 are again actuated. A cam-shaft 157 is mounted in the frame and engages a continually rotating driving-shaft 173 through a clutch 176, 175. A spring-urged roller 191 engages a notch in a disc 193 on the cam-shaft and stops it after each revolution. When a lever 182 is pressed to raise a plate 183, a spring 177 clutches the camshaft to the drive-shaft. If the lever 182 is then released, after one revolution a pin 186 engaging the plate 183 opens the clutch. Feeding sheets. A carriage 19 has rollers 18 running in grooves 17 in the bar 16 and is reciprocated from the cam-shaft through a cam 156, rod 150, lever 144, and lever 161 having a sleeve 159 sliding on a pin 158. The carriage supports two studs carrying a plate cranked upwardly at 33 to which is hinged a plate 34, the plates 33, 34 constituting a gripper for the copy sheets. When the carriage is in its righthand position, the gripper is opened by a lip 39 of the feed table engaging the plate 34. At all other times, a compression spring 37 closes the gripper. Moistening copy sheets. A cylinder 125, Figs. 6 and 8, containing liquid, extends the length of and is secured to the bracket 48 and contains a wick 130. The cylinder is partly open at one end, which is located in a recess 133, in the plate 51, and the wick contacts an absorbent pad 132, one end of which is exposed between vertical guides 135, 136 on the plate 51. In the guide slides a box-like member 137 containing an absorbent pad 142 exposed at the bottom and in a slot 141. When the member 137 is lowered, the pad 142 contacts the pad 132 and its lower edge rests on the copy sheet. The member 137 is reciprocated by means of a cam 195, levers 196, 197, 198, 200 and a pin 140. Printing action. A cam 201 acts on a lever 202 and a push rod 118 to actuate the toggle levers 110, 112 and lower the slide 115 and strips 122 and press the master sheet 73 against a copy sheet on the printing table 40. The presser is raised by springs 121. Moving master sheet. Between each impression, the master sheet is moved a distance equal to the space between two lines of writing thereon. A cam 194 rocks a lever 106 and through a bell-crank lever and a ratchet-andpawl mechanism one of the rods 74 is rotated to move the sheet 73, the roller 53 being rotated at the same time by a belt drive from the rod 74. A pin is adjustable along a slot in the bell-crank lever to control the amount of movement. Alternatively, the roller 52 or 53 can be manually turned to move the master sheet, Operation. A copy sheet is placed in the gripper 33, 34 and the lever 182 pressed to start the cycle of operations. The carriage is moved to the left, the gripper closes, and the copy sheet is brought to the impression table. The member 137 is lowered to bring the pad 142 on to the moving copy sheet and moisten it. When the copy sheet is in position, the member 137 is raised. The presser is then lowered for impression and raised, and the carriage returned until the gripper opens and the copy sheet can be removed and replaced by a new one. The master sheet is moved into position for the next impression. The cams are arranged to produce the desired sequence of operations. According to the Provisional Specification the strips 12 may be of the material sold under the Registered Trade Mark " Perspex."