Patent GB-721988-A (GB)
Title: Elevator dispatching and control system
IPC: B66B1/20
Filed: 1952-12-15
Abstract: 721,988. Electric lifts. OTIS ELEVATOR CO. Dec. 15, 1952 [Dec. 15, 1951], No. 31762/52. Class 40(1). In a multi-car lift system different operating programmes may be selected so that despatching of cars may be effected in response to calls or under time control. Timed despatch of cars may be contingent upon a service demand or not according to the program selected. The system described may function with or without a car attendant and any of four operating programs are selected by a switch TPS, Fig. 3, viz: " Uppeak," Down-peak," " Light or intermittent " and "Up-Down" traffic conditions, "Up-Down" corresponding to sustantial traffic in both directions. Under up-peak traffic conditions, the cars are despatched in the up-direction from the main landing on a timing basis and are despatched downwards immediately after answering their highest calls. Under down-peak traffic conditions, despatching of the cars in the down direction is on a timing basis and the cars are despatched in the up direction as soon as they reach the main landing. Under up-down traffic conditions the cars are despatched in both directions on a timing basis, or, from the main landing, prior to the expiration of the timing interval when certain conditions arise. For light or intermittent traffic the cars are despatched upwards from the main landing in response to calls, and downwards as soon as they have answered their highest call. The cars are selected in advance for despatching upwardly except for down peak traffic conditions, and are selected for despatching downwardly for down-peak and up-down traffic conditions. Selection for basement service is also provided. Despatching is effected by giving despatching signals to the car attendants who then start the cars or, in the case of " withoutattendant" operation, automatically. With automatic operation the doors close automatically at the end of a door time interval which is varied according to whether the stop is in response to a car or a landing call and whether or not the stop is at the main landing on a downward trip. Car Controls. A three car system serving a basement and six floors 1 ... 6 is described. Figs. 4, 6, 7 show the power and control circuits for one car, A. Each car is hoisted by a Ward- Leonard controlled motor, and includes a basement button CBa, Fig. 3, floor buttons C1a ... C6a, Fig. 6, a starting button SBa, Fig. 7, reversing buttons RUBa, RDBa, and non-stop button NSBa, Fig. 4, door-open button DOBa, Fig. 3, and door close button DCB1a, DCB2a, Fig. 7. Associated with each car is a selector machine SM, Fig. 2, including a crosshead 26 driven through a toothed tape 17 and transmission 22, 24 in accordance with the car movements. The crosshead carries a carriage 28 movable from a neutral position relative to the crosshead. When the car is at rest, the carriage is at neutral. It is advanced a predetermined amount relative to the crosshead at the starting of the car. Thereafter it moves rigid with the crosshead, until, as the selected floor is approached, the carriage is brought to rest. The crosshead continues to move until the carriage advance is taken up when the crosshead and the car are stopped. This relative motion of carriage and crosshead, which is effected by a torque motor BM, controls the acceleration and deceleration of the car by means of sequentially operated contacts SLS1 ... SLS4 during the relative motion. The carriage carries pawls 33, retractable by an electromagnet PM, and co-operating with stopping lugs 34 for each floor, for control of the torque motor. Brushes CABa for car call pick-up, UPBa for up and down landing calls respectively, BUHHa, BDHHa for highest landing calls, Fig. 6, are carried on a panel on the carriage and coact with stationary contacts, one for each floor, carried on floor bars 35; Fig. 2. This panel also carries an elongated brush HCBa, Fig. 6, for engaging hook switches HC2a ... HC5a on associated floor bars for highest car call operation, and a pair of switches U1S, D1S, actuated by cams ISC one for each floor for resetting the pawl magnet PM. The panel carries further brushes ULBa, DLBa, Fig. 5 for controlling the up and down hall lantern circuits. The crosshead carries a switch DZ actuated at each floor by cams DZCB, DZC1 ... for determining the zone of door operation. Further contacts carried by the carriage panel and the crosshead are referred to later. Light traffic; preparatory operations. The selector switch TPS, Fig. 3 is positioned to operate the light traffic, relay LT. For " with-attendant" operation two-way switches TOla ... are moved to position w as shown. Assume the system to be started up with car A, only, operating, and located at the main landing, with the car gate and hoistway door closed. Switch MGSa, Fig. 3, is moved to its upper position and operates the auxiliary door open switch XDOa, Fig. 3, and potential switch CAa, Fig. 7. The main landing switch MLa and the self-latching direction holding switch DGa, Fig. 4, also operate in turn. The home landing relay HLRa, Fig. 3, energizes over a brush HLBa (on the carriage panel), and the auxiliary up direction switch DGUa, and auxiliary highest call reversal switch HRXa, Fig. 4, also operate to set the car for upward travel. Through a brush DSBa, (on the crosshead) the auxiliary time relay ATRa, Fig. 4 is operated, and in turn operates the despatching removal relay XCSa, Fig. 4, selection relay SCa, Fig. 3, and the non-stop relay NOa, Fig. 4 which lights the up-hall lantern UHL1a, Fig. 5 over brush ULBa. The door open switch DOa, Fig. 7, is energized over the door zone switch DZa (on the crosshead) and operates the door-operating motor DMAa to open the car gate and main landing hoistway door. With-attendant, car button operation. Up calls. Car calls are registered by the attendant pressing the appropriate car buttons, say C4a, C5a, whereby the highest car call switch HGa, Fig. 6 is operated over the car-button C4a and actuates the highest landing call switch HJa, Fig. 3. To start the car the start-button SBa, Fig. 7 is depressed to operate the starting relay SRa, which energizes the operating coil of the pawl magnet PMa, Fig. 7, to retract the pawls 33, Fig. 2 and operate the pawl magnet relay PMYa, Fig. 7, which extinguishes the up hall lantern at the first floor and energizes the torque motor BMAa to advance the carriage in the up direction. At the same time, the starting relay SRa operates the door close switch DCa, Fig. 7, to close the door and gate, when the brake switch Ha and up direction switch USa are operated. The starting button may then be released. (The doors re-open if the start button is released before closure thereof.) The switches USa, Ha, energize the hoist-motor MAa and release the brake thereon by energizing the brake coil BRa. The sequential closing of the switches SLS2a ... SLS4a, as the carriage advances, operates speed control switches EYa, Ea, Fa, to accelerate the hoist motor and operate a relay SHa. As the car nears the fourth floor the up-top-initiating switch UISa, Fig. 6, is opened by cam ISC4a. Later the brush CABa (on the carriage panel) engages floor contact CP4a and slightly later the switch UISa runs off the cam and closes to energize the reset coil PMa of the pawl magnet, Fig. 6, through the car button C4a. The pawls 33 are thereby moved to their outward position shown in Fig. 2, and slightly later they engage the fourth floor stop collar 34 to stop the carriage. The resetting of the pawls also de-energizes the relay PMYa to deenergize the torque motor BMAa and light the fourth floor up-hall lanterns UHL3a over brush ULBa. The crosshead continues to move upwardly taking up the carriage advance and opening contacts SLS4a ... SLS1a in succession to slow down and stop the car, and de-energize switches USa, Ha, which brake the hoist motor. Slightly before the car is stopped the door zone switch DZa closes to energize the door open switch DOa, which opens the car gate and the fourth floor hoistway door. If the start-button has not been released closure of the doors is prevented by the relay SHa. If it has been released it is again pressed by the attendant to restart the car to answer the car call for the fifth floor in a similar manner. With-attendant, floor button operation. Up calls. The up and down landing buttons UB, U1 ... U5, D1 ... D6, preferably comprise glow-discharge tubes which fire when touched and serve both to indicate and register a call. Assume an up landing button, say U2, to be operated above the car when it is responding to an up car call for a higher floor. When the brush UPBa contacts the floor contact UH2a for the second floor, an auxiliary stop relay HSa, Fig. 6, is 'operated, which in turn operates a landing stop time switch HSXa. Slightly later switch UISa is closed whereby the reset coil PMa, Fig. 6, of the pawl magnet is energized to stop the car at the second floor, and light the up hall landing light thereat as above described, return the landing button U2 to normal and deenergize the stop relay HSa. Car or landing calls are thus answered in the order in which they are reached regardless of the order in which they are registered. With attendant, downward operation. When the car answers its highest call it is automatically set for downward travel by resetting the direction holding switch DGa, Fig. 4, and operating the down-direction switch DSa, Fig. 7. When car A reaches its top terminal brush ARBa completes a circuit for the reset coil of switch DGa, causing switches DGUa, HRXa to drop out and auxiliary down direction switch DGDa to operate to set the car for downward travel. At the same time any operated car buttons are released. Upon the operation of the start button, the torque motor BMAa is energized to advance the carriage in the downward direction and the hoist motor is started in the down direction in a similar manner to that described above for up movement. Stops a