Patent GB-311445-A (GB)
Title: Improvements in or relating to electrical control systems for elevators, hoists and the like
IPC: B66B1/18
Filed: 1928-02-11
Abstract: 311,445. Associated Electrical Industries, Ltd., (formerly Metropolitan-Vickers Electrical Co., Ltd.), (Westinghouse Electric & Manufacturing Co.). Feb. 11, 1928. Electric push-button systems.-A lift system ,comprises a plurality of cages each equipped with up and down starting switches for initiating movement of the cages past one or more intermediate floors, control circuits containing both up-call and down-call switches at each of the floors and common to all the cages for stopping automatically at any desired floor the first only of the cages travelling in the called direction to arrive at the floor, and means whereby the automatic stoppage of a cage at any selected floor is effected by inductive action between devices on the cage and fixed devices which are located adjacent the floor and are adapted to be rendered effective upon actuation of a call switch pertaining to that floor. Figs. 1 and 2 show a lift system comprising two cages A, B serving five floors. Each hoisting drum D, is coupled directly to the armature EM<1> of a motor EM provided with a separately excited field winding EMF. The armature EM' is connected in loop circuit with the armature G<1> of a generator G of the compound wound type including a separately excited field winding GF and a series field winding GSF. The generator G is driven continuously by a motor M of the shunt wound type. Tha direction and speed of operation of a cage is controlled through up and down direction switches 1, 2, speed switches 3, 4 and direction selecting switches 5, 6. Push buttons 7, 8 on the cage A are provided for starting it in the up and down direction, respectively. At the second, third and fourth floors are provided up and down push buttons 2U, 2D ; 3U, 3D and 4U, 4D, respectively, which control relays 2RD, 2RU, etc. for the purpose of causing the stoppage of the first cage to approach the floor which is travelling in the corresponding direction. Each floor has up and down directional relays 2AD, 2AU, etc. for the cage A and 2BU, 2BD, etc. for the cage B. A transfer relay 2TA, 3TA, 4TA, 2TB, 3TB and 4TB is provided at each floor for each cage. Bye-pass relays 2XA, 3XA, 4XA, &c. are provided for permitting a loaded cage to bye-pass registered calls at the will of the attendant. Each cage has stopping push-buttons 2A, etc. ; 2B, etc. for each floor. The stopping mechanism is of the inductor relay type wherein an energized coil is so arranged with respect to a switch that it is capable of operating it only when a magnetizable inductor plate P is brought adjacent the energized coil. Two of these relays are mounted in the well adjacent each floor for each direction of travel, one of which controls the reduction of speed and the other controls the final stopping of the cage. The speed reducing relays are marked 2SAU, 2SAD, etc.; 2SBU, 2SBD, etc. and the final stopping relays are marked 2FAU, 2FAD, etc.; 2FBU, 2FBD, etc. Levelling switches LAU, LAD, mounted on each cage are retracted by coils RC, RC<1> when the cage is in condition to be actuated, but may be projected into the well for engagement by levelling cams C, C<1>, a pair of which is provided for each floor. The cams are arranged so that the rollers R, R<1> of the switches will have just passed off the high point of the cam when the cage is level with the floor. When the cage A is at the first floor, it is started upwards by the attendant pressing button 7 which completes a circuit for closing updirection selecting switch 5 and up-direction switch 1. Holding circuits are provided for the direction switches which extend through normally closed contact members on the switches LAD, LAU. As the speed switch 3 is arranged continuously to be energized when one of the relays 2SAU, 2SAD is moved to open-circuit position, the resistance 30 will be short-circuited and the speed of the motor will increase. When the voltage output of the generator reaches a predetermined value, the coil of relay 4 will actuate its contact members and thus short-circuit resistance 31. Thereafter the motor will run at its maximum speed. The actuation of switch 5 completes a circuit for energizing the relays 2AU, 3AU, 4AU. A person at the third floor wishing to travel upwardly will push the button 3U which completes a circuit for energizing the slow-down and stopping relays 3SAU, 3SAD, 3FAU for cage A, and 3SBU, 3SBD, 3FBD and 3FBU for cage B. As the cage A approaches the third floor, the plate P closely approaches the energized coil of the relay 3SAU, and the magnetic field set up causes the relay 3SAU to be rotated about its pivot 48 to open its contact members 49, thus opening the circuit of speed relay 3 which includes the normally closed contact members of each of the speed reducing relays in series relation, the normally closed contact members of each of the final stopping inductor relays, and door switches 54, 55, 56. The reinsertion of resistance 30 causes a reduction in the speed of the motor. Similarly when the cage approaches more closely to the floor, the relay 3FAU will be actuated to release the retiring leveling switch LAU which is projected into the well to engage the cam C, and thereby opens contact members 36 in the holding circuit for updirection switch 1. Accordingly the cage stops. If the cage stops short of the floor level, the levelling switch LAU will be in position to engage its roller R<1> with the high point of the cam C', and a circuit will be closed for actuating the up-direction switch 1 to continue the movement of the cage until it arrives at the floor level. If the cage over-runs the floor, the roller R of the switch LAD will engage the high point on the cam C, and the down-direction switch 2 will be energized. When the third floor door is opened, the switch 80 is moved to the left and completes a circuit for energizing the restoring coil 81 of relay 3RU, and thereby prevents any cage subsequently approaching that floor from receiving the stop call for that floor. When, the passenger enters the cage, the attendant presses either the button 7 or 8 according to the desired direction of travel. If the passenger wishes to travel to the fourth floor, button 4A is next pressed and this completes a circuit which includes the normally closed contact member 88 of door switch 89 for the fourth floor door 4DA and the coil of transfer relay 4TA. The actuation of this relav disconnects the inductor relays for the fourth floor from possible energization from an outside call-button, e.g. 4U, and completes an additional circuit for the inductor relays. Accordingly as the cage approaches the fourth floor it will be slowed and stopped automatically. If the cage is loaded and it is not desired to stop in response to outside calls, a bye-pass button 94 is actuated to open the circuit between the push-button relays by means of the actuation of the bye-pass relays such as 4XA, 3XA, 2XA. Parallel connections are provided for connecting the contact members of the push-button relays such as 4RU, 4RD to cage B by way of groups of conductors 100, 101. These conductors may be extended through as many cages as are in the bank. The restoring circuits for the push-button relays 3RU, 2RU, etc. also are connected to the other cages by groups of conductors 104, 105.