Patent GB-915136-A (GB)
Title: Counting and printing machanism
IPC: G06M1/10
Filed: 1960-05-23
Abstract: 915,136. Counting-apparatus. WETZER, H., [trading as WETZER KOMM.-GES., HERMANN]. May 23, 1960, No. 18034/60. Class 106 (1). An electromagnetic counting and printing mechanism comprises a stepping magnet with a double-ended armature, one end carrying a return spring and the other end of a link connected to a double-ended stepping pawl engaging a ratchet which is fixed to a type wheel which also carries a cam wheel adapted to operate electrical contacts. As described, a six denomination counter has numeral wheels in the form of type wheels 14, the actuating electromagnets 1 for the respective denominations being arranged alternately on opposite sides of a plane through the type wheels 14. Each electromagnet 1 has a double-ended armature 6, one end being attached to a return spring 29 and the other end to a link 7 the other end of which is pivoted eccentrically on a double-ended stepping pawl 8 engaging a ratchet wheel 17 attached to the type wheel 14. Screws 3 enable the electromagnet to be adjusted with respect to its armature. Each type wheel 14 carries cams 15, 16 adapted to engage followers such as 21 actuating electric contacts 22 connected via springs 18, 19 to connector blocks 24, 25. The cams serve to provide electrical tens transfer signals or to provide external signals or act as zero indicators. Printing mechanism, Fig. 4. A separate printing electromagnet 36 is provided for each type wheel 14, energization of the magnet 36 causing its armature 38 to move a push-rod 34, thereby bringing a pressure head 31 to bear against the printing tape (not shown) and associated type wheel 14. The electromagnets 36 may be actuated by a clock or by a machine whose operations it is desired to count and record. Modification, Fig. 6. The tension in the return spring 29 may be varied by attaching its remote end to the armature 43 of an auxiliary electromagnet 44. When the auxiliary electromagnet 44 is unenergized, the return spring 29 exercises a greater restoring force on the armature 6 than when the auxiliary electromagnet is energized. Thus the counter can be made to respond only to pulses exceeding a predetermined magnitude. Further, by arranging for adjacent type wheels 14 to be locked together in pairs and arranged for rotation in opposite directions by their respective electromagnets 1. When the auxiliary electromagnet 44 on one side of the assembly is energized to detension the associated return spring 29 arid the actuating electromagnet 1 on the opposite side is energized, the type wheel 14 is rotated in one direction, the energization of the auxiliary electromagnet enabling the associated ratchet wheel to move against its stepping pawl. The type wheel can be rotated in the other direction by energizing the other auxiliary and stepping electromagnets. In an assembly such as that of Fig. 2, which would provide three decades for addition and subtraction, the three units on each side of the assembly may have their return springs coupled to a single auxiliary electromagnet. A ball clutch (Figs. 7, 8, not shown) may be provided for a counter required to count additively only, the clutch preventing inadvertent backward rotation of the type wheels. The ball of the clutch may be magnetically controlled so that it can be rendered inoperative to allow for reverse rotation when this is in fact required.