Patent GB-402111-A (GB)
Title: Improvements in electric lifts or elevators
IPC: B66B1/08
Filed: 1932-05-17
Abstract: 402,111. Master control of D.C. motors; actuating controllers. WOOD, W. and WADSWORTH & SONS, Ltd., W., High Street, Bolton. May 17, 1932, No. 13990. [Class 38 (iii).] In a lift system of the variable voltage controlled type, a floor selector driven positively by the cage causes deceleration to commence at a predetermined point on approaching each floor, or at a floor selected by the attendant, and a decelerating rheostat, also positively driven in unison with the cage and under the control of the floor selector, operates step-bystep in unison with the cage movements so that deceleration to any desired slow speed is effected automatically in a predetermined distance of travel of the cage. The rheostat a, Fig. 1, is coupled in the field b of a generator c driven by a motor d, and is controlled by a cam shaft e, the cams f on which can be adjusted angularly to give any desired time interval between the operation of the several contactors g. The cam shaft is driven by a shaft k, Fig. 2, which is driven by the hoisting motor h through a chain drive i. On the accelerator side the shaft k is connected by gears m, and a clutch controlled by a solenoid s to a drum o to which the ends of two chains p are anchored. The other ends of the chains are secured to a drum q on the shaft e, the arrangement being such that whichever way the drum o is turned, the shaft e is turned in a constant direction. A counterweight connected to the drum tends to maintain the shaft e always in its mid, or neutral position. On the deceleration side the arrangement is similar, but the drum ql is clutch connected to a gear t which meshes with a gear u on the shaft e. The clutches connecting the parts n<1>, o<1>, and q<1>, t, respectively, are controlled by a solenoid s<1>, and when disengaged, the turning of the shaft e by the accelerator drive does not affect the deceleration drive, which can therefore be started at any time irrespective of the extent to which the shaft e has been turned bv the accelerator drive. A switch 16 in the circuit of the solenoid s<1> is closed by a cam f<1> on the shaft e when the latter commences to turn in the accelerating direction. The solenoid s is controlled by automatic floor selector switches 1-6 which are actuated by a drum v<1> driven from the cage by an endless rope w. The nrst three switches control deceleration at floors 1, 2 and 3, respectively on the up journey, and the last three switches control deceleration at the same floors on the down journey. The appropriate switches for upward travel are closed by the solenoid x, and the reversing switches are closed by the solenoid y. The solenoid z, the circuit of which is closed by the brake solenoid operated switch z<1>, controls a loop switch 7 in a circuit linking the armatures of the generator c and the motor h. A switch 8, also operated by the brake solenoid, is in a circuit containing a resistance 81 in series with the brake solenoid winding 9. The winding 9 is kept energised, and the loop circuit controlled by the switch 7 is not broken until the motor h has been brought to rest. If the movable parts 10, 11 of the attendant's switch on the cage are moved to the right, Fig. 1, so that the part 10 engages the contacts 12, 13, 14 but the part 11 does not engage its contact 14<1>, 17, the solenoid x is energised to set the switch for up travel, the brake is released, the solenoid z is energised and the loop circuit closed by the switch 7. The motor h turns slowly, and drives the shaft k, through the chain i. When the part 11 of the switch is engaged with the contacts 14<1>, 17, the solenoid s is energised and the drum o is clutched to the gear n. Thereupon the shaft e is turned to accelerate the motor. The part 11 can now be returned to its initial position for the circuit through the solenoid s is maintained independently of the contacts 14j, 17. On approaching a floor, e.g. the first floor, the appropriate switch, in this case switch 1, is opened, and the circuit through the solenoid s is broken thus releasing the drum o, and also closing the switch 15 to energise the decelerating solenoid s<1>. The drums o<1>, q<1> are now clutched to the gears n<1>, t, and the shaft e is turned in the reverse direction successively to open the contacts g until the motor h is brought to slow speed. The attendant then releases switch 10, and the motor is brought to rest. The switch 10 is moved to the left for a downward journey. If it is desired to pass any particular floors, the attendant keeps the part 11 in engagement with its contacts, thereby short-circuiting the floor selective switches 1-6, until the cage has passed the floor immediately preceding the floor at which it is desired to stop.