GB748542A - Electromagnetically driven counter - Google Patents

Abstract

748,542. Counting-apparatus. STANDARD TELEPHONES & CABLES, Ltd. Aug. 31, 1951 [Aug. 31, 1950], No. 20603/51. Class 106 (1). A counter comprises a plurality of numeral wheels each of which is advanced in step-by-step manner by means of a pawl-andratchet mechanism actuated by an electromagnet. Each wheel has a projection which closes the circuit of the succeeding electromagnet to effect transfer. For zerozing each electromagnet is repeatedly energized until a projection on the associated wheel opens the electromagnet circuit. Each numeral wheel 11, Fig. 1, its actuating mechanism and electromagnet are mounted as a unit. The two solenoids 2 are fixed by screws 3 to a U-shaped member 1 which carries the brackets 16, 17, Fig. 2, between which the wheel spindle 15 is mounted. The armature has two arms 7 and 4 and is pivoted at 5. A spring pawl 6 is fixed by screws 9 to the arm 4 and cooperates with a ratchet wheel 10 fixed to the numeral wheel. The numeral wheel has two projections 13, 14 which co-operate with two spring contact switches 23, 24 as described later. In operation when the electromagnet 2 receives an impulse from a stepping relay 43, Fig. 6, the armature 7, 4 is rocked clockwise to lift the pawl 8 on to the succeeding tooth of the ratchet 10. When the impulse ceases the electromagnet de-energizes and the pawl 8 steps-on the ratchet 10 and the numeral wheel 11. Transfer. When the numeral wheel reaches " 9 " the projection 13 closes the switch 23 so that the circuit to the next higher electromagnet 2 is closed. The two electromagnets will thus be energized upon the reception of the next impulse and their associated numeral wheels stepped on. Zeroizing. All the electromagnets 2 are connected to a relay 44, Fig. 6, each through a circuit including the normally closed switch 24 which is opened upon each movement of its associated armature. Each magnet is therefore repeatedly energized and its associated numeral wheel stepped-on upon operation of the restoring relay 44. When a numeral wheel is at zero its projection 14 maintains the switch 24 open so that the circuit to the electromagnet is broken and the wheel remains stationary.