Patent GB-678112-A (GB)
Title: Improvements in or relating to rotary duplicating machines
IPC: B41L11/00
Filed: 1950-04-21
Abstract: 678,112. Rotary duplicators; printing-surfaces. RITZERFELD, W., and RITZERFELD, G. April 21, 1950 [Oct. 1, 1948], No. 9867/50. Class 100 (ii). In a rotary duplicating machine, an arrangement for clamping the printing member to the drum comprises a tapering guide channel formed by the drum and a guide table, down which the printing member is fed, and means for turning the drum backwards until it abuts a stop in which position its clamping device is in register with the narrow end of the tapering guide channel. In the arrangements described, the clamping member may be released when the drum is turned back to its limiting position, either manually or automatically. In either case, after insertion of the printing member it is automatically clamped to the drum by rotation thereof in its running direction. In one example, Fig. 1, shows the drum 2 in its normal position and Fig. 2 the drum turned back with the clamp 8 released to receive the printing member 9, which is passed down between the guide table 10 and drum 2; 5 is the feeding table, 7 a damping device and 3 a rubber impression roller. To turn the drum back, handle 11 is moved in the direction of arrow B, this rotates gear 12 fast with the handle and hence gear 13 fast with the drum, until the position shown in Fig. 2 is reached. In this position a pin 15 fast with gear 12 meets an abutment on lever 16, freely pivoted on the drum spindle. The clamping device is then released by pulling handle 19 to rock lever 17 about its pivot 18. This causes a cam face thereon to engage roller 20 and move the clamping device 8 radially outwards against spring 21, until the roller drops into a retaining recess 22 in lever 17. After insertion of the printing member, handle 11 is moved in direction D to rotate the drum in its running direction. This causes the lever 17 to strike abutment 23 which trips the lever to release roller 20 from recess 22 whereupon the clamping device 8 is spring urged radially inwards to clamp the printing member. In a modification, Figs. 4 and 4a, only one handle is employed. Fig. 4 shows the parts in the normal position and Fig. 4a shows the drum rotated backwards and the clamp 63 opened. When the handle 45 is moved to the right it swings the arm 52 whose top end engages a projection 54 on the drum 55 to rotate the latter backwards to the position shown in Fig. 4a. This rotation brings the roller 56, carried by clamp lever 57 which controls the position of clamp 63, into contact with the cam face on the end of pivoted lever 58 which is normally held in the position shown in Fig. 4 by a spring 61. Movement of handle 45 to the right also pulls link 49 whose other end is pivoted to an arm 51 freely mounted on shaft 50. This causes pin 62 on link 49 to engage and move lever 59. Lever 59 is fast with cam lever 58, whereby the latter is moved to open the clamp 63. After insertion of the printing member handle 45 is moved to the left. This permits the clamp 63 to move radially inward of the drum, and owing to the lost motion connection between the handle 45 and link 48, clamping of the printing member on the drum is completed before the drum is turned to the position of Fig. 4. During subsequent printing operations the clamp is not released since the roller 56 on the clamp lever 57 passes behind the cam lever 58 and deflects the latter.