GB1168417A - Printer - Google Patents

Abstract

1,168,417. Selective printing. INTERNATIONAL BUSINESS MACHINES CORP. 5 Aug., 1968 [21 Aug., 1967], No. 37214/68. Heading B6F. A selective printer includes a platen 18 which is movable towards or away from type elements in a carrier 12 under the influence of a sensor 61 detecting the thickness of a document 16 to be printed on. The platen 18 is urged by a spring 58 against a wedge bar 32 which is movable longitudinally of the platen by a cam 54 driven by an electric motor 52 to adjust the positions of cam surfaces 34, 36 on the bar 32 relative to fixed wedge blocks 38, 40. The movement of the platen is constrained by a pin 50 engaging a slot 48 in the platen in a direction perpendicular to the line of type in the carrier 12. In operation, a document is removed and replaced by first swinging a gate 14 carrying the carrier 12 about a pivot 15, a three-pole, two-way switch 100 being closed thereby so that the motor 52 is actuated and the platen is retracted fully to a point where a stop 82 opens a switch 80. Closure of the gate 14 throws the switch 100 so that the motor is reactuated, driving the platen towards the type carrier 12 until the sensor 61 engages the document and a flange (Fig. 2, not shown) on the carrier, a latch lever 64 bearing the sensor then pivoting so that a spring biased lever 68 is released, thus acting to open a switch 70, and stopping the motor 52. Such movement of the platen closes the switch 80, preparing for another cycle. Retracting movement of the platen acts to latch the lever 68 in a position closing the switch 70. Locking devices.-As the platen moves towards the type elements, an arm 84 is urged towards a limb of the gate 14 so that when the gate is opened the arm 84 moves into a position preventing closure of the gate until the platen is fully retracted. Hammer impression.-The type elements (17), Fig. 2, not shown, are pivotally carried by members. (28) disposed in a train along a rail (30) guiding the type elements past a print line. A row of print hammers (24) are actuated through push rods (26) to effect impression. A resilient impression control member (32) limits the velocity of the hammers.