Patent GB-669407-A (GB)
Title: Electrical plant
IPC: B66B1/08
Filed: 1949-02-22
Abstract: 669,407. Electric lifts. KASSEN-AUFZUGS-UND MASCHINENBAU AKT.-GES. F. WERTHEIM & CO. Feb. 22, 1949. [March 10, 1948] No. 4836/49. Class 40 (i). 4 18 In an elevator or like system, the cage driving motor is controlled from the various landings or from the cage itself by a stepping switch to which varying numbers of control impulses are sent from the operative control point by means' of a dialling switch such as used in telephony, the stepping switch controlling the motor through a follow-up member driven by the motor. Stepping switch construction, Figs. 1, 2. Energization of the drive magnet AR, Fig. 1, rocks a pawl 33 to step a ratchet wheel 7 freely mounted on a collar shaft 6. The wheel 7 is coupled to a freely mounted concentric wheel 8, Fig. 2, through dogs 10, 11 on the respective wheels, for forward rotation only, so that stepping of the ratchet 7 by pulsing of the drive magnet AR advances the wheel 8 correspondingly causing a radial wiper arm 15 rigid with the wheel 8 to wipe over selector contacts 16 arranged in a semicircle on a fixed insulator disc 4. Connection is made by the selected contact 16, Fig. 2, through its associated radial element 18 and fixed wiper contact 19 with one or' other of two contact segments 20, 21 insulatingly carried on a disc 24 concentric with the shaft 6 and adapted to be driven through a clutch 27 to follow-up the arm 15. A release magnet HR when energized rocks both the drive pawl 33 and the pivotal locking pawl 38 out of engagement with the ratchet wheel 7 through pivot levers and at the same time through levers 41, 40 applies a brake 40b to the wheel 8. The wheel 7 then returns to its initial (normal) position under gravity owing to its eccentric weighting, but the wheel 8 and the wiper arm 15 are held in the operated position until the release magnet HR is deenergized when the wheel 8 is returned to its normal position by a spring 14. In some cases the arm 15 may coact directly with the followup segments 20, 21. Elevator operation, Fig. 3. The cage C may be called to any floor by operating the dial switch AK at that floor or by dialling the appropriate number on the switch KI in the cage. Such an operation de-energizes the normally energized signal lamp relay LR and pulses the relay AR to step the switch arm 15 to select the "floor" required. The appropriate "up" or "down" contactor coil spa, spb is thereby energized over the appropriate segment 20, 21 of the follow-up switch SG to drive the cage in the corresponding direction during which time interruption of the control circuit, e.g. by operation of the switch at another floor, is prevented by shunting the slow-acting contact kv of the lamp relay, and the inoperative contactor is also locked to prevent its operation. The operative contactor also energizes the release magnet HR, whereupon, as above described, the wheel 7 returns to its normal position. Slightly before the cage reaches the selected floor the normal energizing circuit of the operative contactor is broken by the follow-up switch disc 24 which is driven in correspondence with the cage but the contactor circuit is maintained over a previously energized self-locking circuit until the cage is finally brought to rest by the normal roll rand rejector A controls at the landing. The relay HR de-energizes as the contactor falls off, whereupon the wheel 8 and switch arm 15 of the follow-up switch return to normal as above described. The follow up switch SG is provided with an auxiliary contact 7b, closed in the offnormal position of the wheel 7, which causes energization of relay HR to return the switch SG to normal should the cage be called from a floor at which it happens to be resting.