Patent GB-604455-A (GB)
Title: Improvements in electric control system for elevators
IPC: B66B1/20
Filed: 1945-06-25
Abstract: 604,455. Electric control systems for lifts. WAYGOOD-OTIS, Ltd. June 25, 1945, No. 16214. Convention date, June 24, 1944. [Class 40 (i)] In a multicar-lift-system wherein an " up " or " down " call registered at one of a plurality of landings is normally arranged to stop a car travelling in the corresponding direction, such a call if unanswered for a predetermined time is arranged to stop a car travelling in the opposite direction. The invention thus obviates undue waiting by intending passengers at landings during busy periods when cars filled to capacity are non-stopped past floors for which calls are registered. The invention is described for a system in which only down calls registered for a predetermined time are given preference. Where a plurality of such calls are registered, preference may be given to the lowest, the highest or the longest of such calls. In each case the preferential call stops an up-travelling car and sets it for downward travel. Preferably, however, only an available up-car, i.e. one which has no push-button within it depressed for a higher floor, is stopped. Car controls.' As shown, two or more elevator cars 1, 2, Fig. 1, are each hoisted by an electric motor 3 supplied from a Ward-Leonard generator 13, and each includes a start control switch,. car floor buttons C2 ... C7, Fig. 2a, for each floor other than the first, a safety switch and a non-stop button NSB. Associated with each car is a floor controller or selector machine 9, Fig. 1, which includes a cross-head 11, driven through a toothed tape 10, gearing and screw in accordance with the car movements. The cross-head 11 carries a carriage 12 which is movable from a neutral position relative to the cross-head. At rest, the carriage is in neutral. It is advanced a predetermined amount relative to the cross-head as the car commences to move. Thereafter it moves rigid with the cross-head, which moves with the car, until upon the appropriate circuits being closed, the carriage is brought to rest. The cross-head continues to move until the carriage advance is taken up when the cross-head and the car are stopped. This relative motion of carriage and cross-head which is effected by a torque motor AM, Fig. 3, controls the acceleration and deceleratidn of the car. The carriage carries retractable pawls co-operating. with stopping lugs provided for each floor. Travelling brushes 38, 48, 58, 68 for each car are carried by a panel on the corresponding- carriage 12 and co-operate with contacts 31, 32 ... 41, 42 ... 51, 52 ... 61, 62 .... &c. corresponding to the respective floors 1, 2 ... 7. Each carriage panel also carries an insulating cam 88 for operating hook switches 82, 83 ... 86 for the second to sixth floor, respectively, and of such a length that it opens a hook switch for any floor slightly in advance of the engagement of the travelling brushes 38, 48 ... with the corresponding floor contacts for both up and down travel. The cross-head of each car carries a brush 90, Fig. 3; which engages' respectively stationary contacts 91, 92 for the terminal floors (7th and 1st). An additional hook switch 122, Fig. 3, is arranged to be opened by cam 88 or a separate cam 123'only when the car is at the 1st floor. Fig: 2a shows the push-button control and' restoring circuits for two cars and Fig. 3 the power and control circuits for one of them. Car starting. Assuming the cars are standing at the 1st floor when power is switched on, then for car No. 1, the non-stop relay NS(1), Fig. 2a, is energized over the non-stop button NSB(1). The up-direction switch operating coil PU and the reset coil of the down-direction switch PD, Fig. 3, are operated over travelling brush 90 and contact 92, the switch PU latching in its operative position. The highest down hall call relay XS(1), Fig. 2a, is energized over contacts PU1(1) and brush 68(1). The auxilary direction relays PR, Fig. 3, is energized over contacts PU3 and the car button magnet CBM over PU4. Over contacts PU6 the field winding AM125 and armature AM126 of the torque advancer motor are connected in parallel. To start the car, the start control switch is thrown to " full running." Contacts 105, 106, 107, Fig. 3; are bridged thereby, contacts 106 operating slightly ahead of the others. The bridging of contacts' 106 closes circuits (not shown) to close the car gate and first' floor hatchway door and energizes over contacts OS1, EA4, the stop magnet operating coil SM which locks over contacts SM3. The auxiliary stopping. switch ASM, Fig: 3, is energized over-contacts SM2 in series with one coil EA of the auxiliary speed relay. EA does not yet operate, but ASM pulls up, and over contacts ASM4 the circuit to the advancer torque'motor AM is made as the start control switch bridges contacts 105. Contacts PU6 being operated, the fields AM125 and AM127 are respectively in parallel and in series with the armature which is therefore rotated to advance the carriage 12, Fig. 1, upwards. As the carriage advances relative to the crosshead, it closes selector switches SS1, SS2, Fig. 3. The second coil of the auxiliary speed relay EA is energized over SS2. This relay now operates and functions to prevent energization of the direction switches PU, PD and re-operation of the stopping magnet once a call has been picked up after the car has come to stop at the floor for which the call is registered. Upon closure of the hatchway door and car gate, the field and brake switch H is energized over SS1, PU7, up limit switch 108, gate contacts G, door contacts DL, contacts 107 and safety switch 110. Over contacts H3 an operating sequence switch relay OS is operated to lock ASM over contacts OS2. The contacts 105, 106, 107 are now all byepassed by contacts H2, H3, H4, so that the start control switch may be released. Contacts H8, H9 complete the circuit for the field 96 of the Ward-Leonard generator 95 and the brake 7, Fig. 1, on the hoist being released by energization of the brake release coil BR over contacts H6, H7 the car motor 98 whose field 100 is separately excited starts the car upwards. The brake, upon being released, operates a relay BK to insert a cooling resistance 103 in series with the coil BR and over contacts BK1 operates a steed switch E which at contacts E1 cuts resistance from the field 96 of the generator 95 to bring the car motor up to full speed. Floor button operation. Assuming that the up third floor button U3 is depressed by an intending passenger prior to operation of the start control switch, the operating coil 3U of the self-latching up third floor relay, Fig. 2a, is energized. At contacts 3U1 the stationary contacts 53(1) are energized so that when engaged by the car brush 58(1) a circuit is completed for the restoring coil 3U of the third floor relay in series with the neutralizing coil SM(1) of the stopping magnet over contacts 3U1, 53(1), brush 58(1), PR2(1), NS1(1), EA(1), SM1(1). The neutralizing coil SM(1) opposes the operating coil of the stopping magnet SM, releasing the retractable pawls on the carriage 12 and breaking the circuits of both coils of the stopping magnet SM at SM(1), SM3, the auxiliary stopping switch ASM and one coil of speed relay EA at SM2. Contacts ASM2(1) close to increase the current flow in the restoring coil 3U of the third floor relay which is now reset. The torque advancer motor AM is de-energized at ASM4. As the car continues its upward travel the up pawl engages the third floor stopping lug causing switches SS2, SS1 to open in sequence. Relay E first drops out to reinsert resistance 101 in the generator field and slow down the hoist motor 98, and then, as the car reaches the third floor landing, SS1 opens, de-energizes the field and brake switch H and brake release coil BR to stop the motor. The operating sequence switch relay OS is also de-energized at contacts H3 provided that the start control switch has been returned to neutral. If this has not been done, the relay OS remains operated and prevents restarting of the car until the control switch has been returned to neutral. Car button operation. Should a passenger now enter the car desiring to go to, say, the fifth floor, the car attendant presses car button C5(1) which is held operated by the magnet CBM. This renders contact 35(1) alive and, operates, over hook switches 85(1) ... 87(1) the highest car call relay XC(1) which at contacts XC1(1) breaks the circuit of the highest hall call relay XS(1). The car is started as before by operating the start control switch. As the car approaches the fifth floor cam 88(1) engages and opens the fifth floor hook switch 85(1) to de-energize relay XC(1). A little later brush 68(1) on the carriage panel engages stationary contact 65(1) to complete again the circuit for the highest hall call relay XS(1) which over contacts XS1 energizes automatic return relay XH, Fig. 3, which locks over contacts XH2, and over XM1(1), Fig. 2a, energizes the neutralizing winding SM(1) of the stopping magnet. This winding is also energized over the operated car button C5(1), contact 35(1) and brush 38(1). It functions to reset the stopping magnet, slow down and then stop the car as described above at the fifth floor. As the car stops, contacts H1, Fig. 3, close to reset the up direction switch PU and operate the self-latching- " down " direction switch PD. This releases the depressed car button C5(1), renders the brushes for upward travel ineffective and those for downward travel effective switches over the circuits of the advancer torque motor AM and the generator field winding for downward travel, and switches the down limit switches 116, 117 in circuit so that when the start control switch is again operated the car moves downwardly. General control arrangements. With the arrangement shown in Figs. 2a, 3, the car when travelling upwards in answer to a call, will respond to intervening up calls made during ascent provided the corresponding floor contacts 51, 52 ...