Patent GB-444698-A (GB)
Abstract: 444,698. Distant - control systems. AUTOMATIC ELECTRIC CO., Ltd., Strowger Works, WOODLAND, C. R., 45, Warnerville Road, Broadgreen, and RHODES, C., Lodore, Childwall Priory Road, all in Liverpool. Sept. 25, 1934, No. 27526. [Class 40 (i)] A device for effecting switching operations in response to predetermined numbers of impulses comprises a ratchet wheel rotated by the impulses and restoring to normal when impulses cease a switching member being operated during said restoration if a predetermined number of impulses has been received. The device may be controlled directly by highfrequency impulses on supply mains or in a local supply circuit controlled by the high frequency impulses, or by other alternating or direct current impulses. Three sets of devices may be operated, one by 2 and 3 impulses to switch shop window lights on and off and another by 4, 5, and 6 impulses to obtain graduated control of street lamps whereas another set operated by 7 and 8 impulses may control consumers' tariff meters. In the arrangement shown in Figs. 1 and 2 (Comp.) a magnet 10 with a shaded polepiece 11, 24 to enable it to respond to A.C. controls armature 13 and spring controlled stepping pawl 14. The armature has two projections, one of which 38 is engaged by dashpot 23 to prevent complete restoration of the armature between impulses, whereas the other 37 is controlled by an armature stop 33 and engages between an armature return spring 21 and a spring 22 formed with a detent for the ratchet wheel 15, 17 which is rotated by the magnet against the action of a spring 16. The notched member 27 and circuit-controlling cam 28 rigid therewith are not rotated forward with the ratchet wheel but are retained by small projections on the circuit controlling spring 29. On its forward (counter-clockwise) movement, detent 26 on ratchet wheel 17 pushes swash plate 30 with it, the plate 30 being pressed against the ratchet wheel bv a flat spring 31. If the number of impulses is a predetermined one the detent 26 slips into one of the notches in member 27 and when armature 13 restores fully, the spring 16 restores the ratchet wheel which moves cam 28 to perform the desired operation on springs 29. If the number of impulses is too small, detent 26 does not reach a notch in 27 while if the number is too great, the tail of detent 26 is trapped against the lower arm of swash plate 30 and is prevented from entering a notch on the return movement of the ratchet. The plate spring 31 may be arranged to mask succeeding notches in the member 27. If any of the devices get out of step, they will be automatically in step again after the full code of impulses to which they respond has been transmitted to them. The Provisional Specification describes a different arrangement in which the ratchet wheel (not shown), in Fig. 2 (Prov.), is held between impulses by a detent on a rotary member 8 having considerable inertia. Rotating with the ratchet wheel is a spring 12 and a detent 11 adapted to engage one of a series of notches in a member 13 which is rotated by the ratchet wheel (counter clockwise), on restoration to normal and controls spring sets such as 19. If the ratchet wheel is stepped too far, detent 11 is tripped by a fixed pin 15 and held tripped by spring 12 until released by a further fixed pin 16 on reaching normal. Specifications 431,349, [Group XXXVII], and 435,564 are referred to.