Patent GB-690779-A (GB)
Title: Mechanism for controlling elevator circuits
IPC: B66B1/52
Filed: 1951-05-08
Abstract: 690,779. Controllers. WAYGOOD-OTIS, Ltd. May 8, 1951 [May 20, 1950], No. 10811/51. Class 38(iii) Control apparatus for an electrically-driven lift comprises a plurality of conductive contacting segments 70, one for each floor, which are mounted on a shaft 40 to be rotated at a speed proportional to that of the liftcar. A plurality of contact devices are arranged on a crosshead 32 which is movable in a direction parallel to the axis of the shaft 40 and the contact devices are biased to engage slidably each segment 70 when the car is within a certain distance of the floor for which the segment is provided. The segments 70 are spaced in accordance with the distance between floors and are helical in form, having a pitch equal to the travel of the crosshead per revolution of the shaft. If it is intended that the car should not stop at a certain floor, an electromagnetic device 55 which is carried by the crosshead retracts the contact devices to clear the segment corresponding to that floor. A drive wheel 27 is driven by a tape which is attached to the car and to the counterweight. The crosshead 32 slides on a vertical tubular member 44 and is driven through chain 31 and reduction gearing 28. The shaft 40 is driven through bevel gears 36, 37. The contact devices engageable by the segments 70 are mounted on a collar 80 which is helical at its upper edge and has helical slots for positioning the contact devices which are arranged in pairs on each side of a pointer 85. Contact fingers 86, 87, are for up and down fast levelling speed operation and contact fingers 90, 91, for up and down slow levelling speed operation. Combined up and down interlock switches and feed contact fingers 92, 93, are provided together with door zone switches 94, 95. The collar 80 is supported by a bracket operated by the electromagnetic device 55, a spring assisting gravity in biasing the armature of the magnet to an unattracted position. A radial slot is provided in each of the segments 70 and is utilized in conjunction with the pointer 85 to position the segment on shaft 40. A panel frame 58 is mounted on the crosshead and carries a plurality of sections 175 of insulating material upon which are mounted a number of brushes 185-187, 190-195, for engaging contacts mounted on floor bars 176. One bar is provided for each floor and the spacing of the bars corresponds to that of the floors. Also mounted on each floor bar is a combined bush and switch which is utilized in the direction-determining circuit for the car. The direction switches are operated by a direction cam comprising a down-section 242 of conducting material and an up-section comprising two members 243, 244, of insulating material. These switches are controlled by the registered calls for the floors for which they are provided and may be connected as shown in Specification 297,801, [Class 78 (ii)]. The control apparatus also comprises an indicator guide chain 62 which is attached to the crosshead 32. A relay compartment is enclosed in the same casing as the control gear, the relay assembly being hinged to allow ready access to the floor bars. Upon starting the car, the electromagnetic device is energised to lift the collar 80 and, as the car upwardly approaches a floor for which a car call is registered, the brush 193 engages the stationary contact for that floor, picking- up the call and effecting its automatic cancellation. The stopping brush 191 is rendered effective to initiate deceleration of the car and the electromagnetic device 55 allows collar 80 to drop the contact devices into a position to be engaged by the levelling segment. The leading edge of the segment runs on to fingers 86 and 90 so that the car is slowed down, and, at a certain distance from the floor, switch 92 is actuated to establish an auxiliary operating circuit for the car and to open the main operating circuit. At this time the car runs at fast levelling speed. Switch 94 is then operated to open the doors, and, as the car arrives in the slow speed levelling zone, the finger 86 is de-energised. Just before the car reaches floor level the finger 90 is disengaged and the car is then brought to a stop. When the car reaches its highest call in its upward travel the cam member 243 operates the direction switch to break the up-direction circuit. This enables a stop to be made during upward travel in response to a downward landing call provided that no call is registered from a floor above. During downward travel the direction circuit is maintained by cam member 242. Contact fingers 86, 87, 90, 91, are of the same construction and are mounted in the same way on the collar 80, Fig. 10 (not shown). Each contact finger has a carbon contact, which is adapted to be engaged by the segments 70, and comprises a contact spring mounted on a base of insulating material which is bolted to the collar. The switches 92, 93, Figs. 8, 9, (not shown) are of the same construction and comprise an arm which is pivotally mounted on the collar 80 and has at one end a carbon contact engageable by the segments 70. The opposite end of the arm carries a forked spring mounting two silver contacts associated with contacts fixed to the collar 80. The arm is biased by a spring which is bolted to a terminal. The door zone switches, Fig. 7 (not shown) each comprise a spring- biased arm having at one end an insulating button engageable by contacts 70, and at the other a contact which co-operates with a fixed contact. Brushes 185-187, 190-194, each comprise a carbon contact mounted on a leaf spring which is secured to a bracket bolted to section 175, Fig 12 (not shown). Brush 195 has a longer contact than the other brushes. A plunger type brush 213 is mounted between brushes 193 and 194. The stationary contacts engaged by brushes 185-187, 190-194, each have a rounded silver tip, those engaged by brush 195 have a flat contact surface, Fig. 13 (not shown). The direction switches each comprise a contact 227 (Fig. 14) and a U-shaped member 228 carrying a contact tip 230 biased by spring 231 to engage a contact tip 232 on the end of spring 233. The movement of spring 233 is limited by member 235.