GB1122482A - Printing machine - Google Patents

Abstract

1,122,482. Printing machines. ENGLISH NUMBERING MACHINES Ltd. 15 July, 1966 [21 Aug., 1965], No. 35972/65. Heading B6C. A printing machine, e.g. a machine for printing numbers sequentially, can be set so that it prints on single sheets with a light resilient pressure or so that a greater pressure is applied when a number of sheets with interposed carbons, or relatively thick documents, are to be printed. The typewheels are carried by a plunger rod 20 mounted in a printing head 10 supported by parallel links 11, 12. A pin 22 on the rod 20 engages a slot 24 on a lever 26 fixed to a shaft 28 to which is fixed another lever 51. The lower end of lever 51 has a pin 50 sliding in a slot 49 in a link 47 and connected to the link by a spring 52. The link 47 is pivoted at 88 to a driven disc 61 of a one-revolution clutch 60. The clutch is operated by a member 32, and for printing with light pressure, the link 47 through the spring 52 and levers 51, 26 moves the printing unit 10 downwardly to print. During this operation, one arm 55 of a double-armed lever 55, 58 is engaged by a pin 97 on a manually settable control member 54, so that a recess 59 with a stop-shoulder 98 on the arm 58 is out of range of a projection 53 on the lever 51. If printing with increased pressure is required, the member 54 is rotated by the operator so as to move the pin 97 away from the arm 55 which then moves into a groove in the member 54 under the action of a spring 57, so that the pin 53 now engages the recess 59. If now the clutch is engaged, the lever 51 is rotated as before until the pin 53 engages the shoulder 98 whereupon the link 47 moves independently of the lever 51 and stresses the spring 52. Subsequently, a pin 83 on the clutch disc 61 strikes the tip of arm 58 to pivot the arm downwardly and release the projection 53. The lever 51 is then free to pivot and drives the unit 10 downwardly under the action of the stressed spring 52. During upward movement of the unit, an adjustable stop 94 is engaged by one of the links 12 to limit upward movement of the head 10, but upward movement of the rod 20 continues to bring the typewheels into contact with an ink pad in the head 10. The unit 10 can be swung by means of a handle 33 into a position wherein the typewheels are readily accessible for adjustment. With the operating link 51 stationary, a member 43 associated therewith holds the links 11 stationary. Movement of the handle 33 causes the links 12 to move the unit about its pivot 14 with the links 11, and the slot 24 engaging the pin 22 on the rod 20 causes the typewheels to be projected. At the same time, an arm on the shaft of handle 33 opens a switch in the circuit of a motor driving the clutch 60.