GB369796A - Improvements in or relating to printing, stamping or recording devices - Google Patents

Abstract

369,796. Printing &c. machines. INSTOGRAPH, Ltd., 1241, High Street, Oakland, California, U.S.A.-(Assignees of Friden, C. M. F.; 15, Caperton Avenue, Piedmont, California, U.S.A.) May 22, 1931, No. 15179. Convention date, May 28, 1930: [Class 100 (ii).] Tripping-arrangements.-In a time-recording or other printing device having a solenoidoperated platen the circuit of which is closed by the insertion of the sheet &c., a trigger is provided which holds apart the contacts of the solenoid circuit and is tripped by the insertion of the sheet, to effect the printing stroke, and then rendered inoperative by the presence of the sheet to avoid unintentional repetition of the impression. The platen 17 is carried by a plunger 18 actuated by a solenoid 19, the circuit of which is completed by contacts 21, 22 drawn together by a spring 28. The contact 21 is carried upon an arm 25 pivoted at 27 and having an aperture 36. The arm 26 is normally held so that contact is broken by a trigger 29, pivoted at 31 and drawn towards the position shown in Fig. 3 by a spring 32. The sheet 34 when inserted on the platen displaces the trigger and allows it to pass through the aperture 36, so that the arm 26 falls, as shown in Fig. 2, contact is made, and the solenoid energized. The upward stroke of the platen disengages the trigger and allows it to return to its normal position, as shown in Fig. 3, and the circuit is also broken so that the platen falls. The sheet is now held between the trigger 29 and the arm 26 and the printing operation cannot be repeated since forward movement of the sheet would cover the aperture 36, and retraction of the sheet leaves the trigger in its normal position.