GB455956A - Improvements in duplicating machines - Google Patents

Abstract

455,956. Duplicating - apparatus ; printing-surfaces. DITTO, Inc., 2243, West Harrison Street, Chicago, U.S.A. March 3, 1936, No. 6421. Convention date, March 9, 1935. [Class 100 (ii)] A duplicating-machine comprises a rotatable drum carrying a clamp for the master sheet from which copies are to be made, and mechanism for guiding the master sheet to the clamp and for stopping the drum with the clamp open and in alignment with the sheet guide. The clamp is formed by a bar 85 held in a recess in the drum 32 by springs 85a and spring-pressed to clamping-position, a bar 88 slidable longitudinally in the drum and formed with recesses engageable by rollers on the bar 85 serving to release the clamp. In order to replace a sheet carried by the drum, a lever 93, normally held against a stop 93b by a spring 102, is rocked so that a pin 101a, engaged by a notch in the lower end of the lever, is released. The pin 101a is secured to the inner end of a table 76 pivoted in the side frames of the machine at 77 and carrying a bracket 78 to which is pivoted an arm 79 pressed against a lug 103 on the inner end of the table by a spring 82, and formed with cam surfaces 80, 84 and a shoulder 94. The released tableswings to horizontal position wherein it is held by the lug 103 engaging the arm 79, the lever 93 being retained in locked position by the pin 101a. The cam 84 is thus swung into position to engage the projecting end of the bar 88, which, on rotation of the drum, is moved to cause the clamping- bar to release the master sheet. A pin 81 on the drum then slides over the cam surface 80 and snaps over the shoulder 94, in which position it engages the end of the lever 93 to stop the drum with the opened clamp opposite the table 76. A new sheet is pushed into the clamp, and the drum is rotated rearwardly. A cam 95 on a spring-pressed lever 96 engages the end of the bar 88 to return it to the position in which the bar 85 can grip the sheet. The pin 81 pulls the arm 79 downwardly, rocking the table 76, so that its end remains in alignment with the clamp, until the pin 101a is in a position to be engaged by the end of the lever 93 which is then pulled by the spring 102 so as to release the pin 81 and permit normal rotation of the drum. The lug 103 on the table restores the arm 79 to normal position.