Patent GB-348045-A (GB)
Title: Improvements in automatic control systems
IPC: B66B1/52
Filed: 1929-12-23
Abstract: 348,045. Electric control systems for lifts ; automatic train control systems. TAKAMINE CORPORATION, 208, Rawson Street, Long Island City, New York, U.S.A. Dec. 23, 1929, No. 39309. Convention date, Feb. 1. [Classes 78 (ii) and 104 (iii).] In a system for controlling remotely a moving object, selective mechanism for controlling the starting and stopping of the object comprises a number of independently-movable members, each corresponding to a position for the object, means for moving one of the members to a pre-selecting position to cause the movement of the object and means for stopping the object depending on the movement of the object combined with a further movement of the member. The selective mechanism, which is described for use in the control of an elevator, may also be used in systems such as automatic train control systems. In the construction shown in Fig. 1, an elevator is controlled bv means of three buttons 38, 39, 40, one on each floor, each button being associated with an electromagnet 109. The armature of each electromagnet is adapted normally to engage in a recessed portion of a member 110 pivotally mounted on a shaft 117. The members 110 are formed with projections 116 for engagement by projections 8, 9, 10 carried by a shaft 11 which is driven by the motor which drives the elevator. Further projections are provided for engagement with vanes 140 secured to mercury switches 148. Assuming that button 40 on the top floor is pressed when the elevator is on the ground floor, the corresponding electromagnet 109 is energized so that the armature releases its associated member 110. This member, acting by gravity, engages a vane 140 to close the switch 148, completing a circuit through relay 27. This relay closes contacts 29, 30 whereby a circuit is completed through main-line relay 3, causing the motor to start. The energization of the relay 27 ensures that the motor drives the elevator in an upward direction. As the elevator approaches near to the top floor the projection 10 engages the corresponding member 110 to cause it to move away from the vane 140. This vane is then restored to normal position, its upward movement acting to close a circuit through leads 49, 50, whereby a magnet opens contacts 153 and the motor stops. In the modification shown in Figs. 2, 4 and 5, electromagnets 109 are provided corresponding to the number of floors to be served, and co-operating with selectively-operable members 110. Each member has a notch 114 on its upper edge and is provided with rollers 122, 123 whereby it may be rotated about a common shaft 117. Associated with each member is a chain 128 adjustably mounted on sprocket wheels 124, 126, and carrying cams 134, 135 for engagement with the rollers. The cams on the several chains are relatively positioned to correspond to the spacing of the floors served by the elevator, the motor of which drives the chains. Assuming that the elevator is in its lowest position and a button is pressed at a certain floor, the corresponding electromagnet 109 is energized to release the member 110, the end 116 of which then engages a counter-weighted bail 140, closing a mercury switch 148. A circuit is then completed whereby the motor is caused to move the elevator upwardly. Meanwhile a pivoted dog 165 on a rocking frame engages in the notch 114 in the member 110. When the elevator reaches the vicinity of the selected floor the cam surface 137 of cam 134 engages roller 122 and rotates the member 110, which, acting on the dog 165, imparts movement to the rocking frame on which the dogs are mounted. This movement causes the separation of contacts 153 whereby the circuit of the motor is opened and the elevator stops. The member 110 moves still further until stopped by the armature 120, the dog 165 being disengaged from the notch 114 by means of a rod 170. The electric circuits used in the apparatus shown in Figs. 2, 4 and 5 are indicated in Fig. 11. The magnets operating the selector members corresponding to the different floors are indicated at FL1 to FL4. US and DS are the mercury switches for controlling the up and down movements, respectively, of the elevator ; and FS is the normally-closed stop contact adapted when open to break the circuit of the motor. When the supply circuit is energized a circuit is complete through conductor 210, lines 233, 232, contact A4, relay TL, line 234 and conductor 202. The relay TL, which is a time-lag relay, is energized, thereby closing contact TL1, and completing a circuit through relay A. This relay at contact A4 breaks the circuit of relay TL, and at contact A3 completes a locking circuit for itself. Contacts A1 A2 prepare circuits through wires 229, 230 which lead respectively to the " up " and " down " pushbuttons at the various floors. The system is then ready to receive calls. If, for example, a button on the third floor is pressed a circuit is completed through conductor 202, contacts UR4 and A1, lines 230 and 212, winding of magnet FL3, and conductor 201. The magnet acts to release the corresponding selector member whereby one of the mercury switches US or DS is closed, depending upon the previous position of the elevator. If, for example, the elevator was below the third floor, the switch US is closed to energize the " updirection " relay UR whereby contacts UR1 and UR2 are closed and contacts UR3 and UR4 are opened, the two latter contacts preventing interference by disconnecting the " down-direction " relay DR and the common wire for the " down " pushbuttons. Contact UR1 completes a circuit for a coil U whereby contacts 29, 30 are closed to complete the circuit of the main-line switch coil ML, the latter causing the elevator to start going up. Contact UR2 prepares a circuit for wire 229 which is independent of relay A. If the " up " button at the second floor is pressed while the elevator is between the first and second floors the second floor selector member will act to cause the elevator to stop at this floor, by opening the stop contact FS. Relay A opens due to the opening of contact FS and therefore contact A4 closes to complete the circuit of time-lag relay TL. This relay after an interval acts and as the third floor member is still in its released position the elevator starts again and continues to move until the third floor is reached.