Patent GB-189916395-A (GB)
Title: A New and Improved Arrangement for Controlling Electric Elevators.
Inventor: WAHLSTROEM EMIL ALFRED
Filed: 1899-08-11
Granted: 1900-08-11
Abstract: 16,395. Wahlstr÷m, E. A. Aug. 11. Lifts, electrically actuated and controlled. Fig. 1 is a diagram of the controlling apparatus and circuits. The cage 1 is suspended from a drum 3 driven by spur gearing from the armature shaft of the driving-motor 4. A countershaft 7 is driven by pulleys 5 and 6 from the cage shaft. This shaft 7 has fixed to it a disc carrying contact-strips 8 and 9. Opposite to it on a shaft operated by a handpulley 12 is a contact-arm 14 in communication with the + lead as shown. When, therefore, the arm 14 is rotated to bring it in contact with either of the plates 8 or 9, a circuit is completed in one or other direction through the field magnets of an auxiliary motor 15. Upon the armature shaft 16 of this motor pinions 18 and 19 are mounted on spring clutches, so that, in one direction of rotation of the shaft 16, one pinion acts to drive the wheel 20, and in the other direction the second pinion acts. Mounted axially with the shaft 21 is a shaft 23, fitted at one end with a clutch 22 and a disc 30 carrying a pin 31 adapted to engage with a bar 32, and thus at the proper time open a switch 34 in the armature circuit of the auxiliary motor. The other end of this shaft 23 is fitted with a radial switch arm 25 adapted to slide over the contacts 27 to 28 of a resistance 29 in the armature circuit of the main motor 4. The shaft 23 is normally forced to the left, and rotated in the direction of the arrow by a spiral spring 26, but it abuts against a lever 44 pivoted at 43 and linked at its free end by rods 41 and 38 to an eccentric pin 36 on the end of the shaft 16. The rod 41 carries the armature 40 of an electromagnet 39 in the starting-circuit. The rod 38 by means of its end 53 during a rotation of the shaft 16 strikes and operates a reversing-key 49-51 for the field-magnet circuit of the motor 4. The action of the apparatus is as follows :-The pulley 12 is rotated to bring the arm 14 and plate 9 into contact. The auxiliary motor is thus started, and the shaft 16 rotated in the direction of the arrow. The pin 36, acting upon the rods 38 and 41 and lever 44, brings the armature 40 up to the energized magnet 39. The clutch 22 is thus brought into action, and the arm 25 in moving over the contacts 28-27 cuts the resistance 29 out of the armature circuit of the motor 4. As this operation is completed, the pin 31 opens the switch 34, and stops the motor 15. The motor 4 then continues to run until the rotation of the shaft 7 brings the insulating-space 10 beneath the arm 14, when the current through the magnet 39 is broken, thus allowing the armature 40, lever 44, and shaft 23 to move to the left to break the contact of the arm 25, and thus stop the motor 4. When the lift stops only at certain points, the arm 14 may be replaced by a number of rigid contactsprings connected to a corresponding number of switches at the different stopping-points. The contacts 8 and 9 may also, to secure exact adjustment, be wound upon a cylinder in the shape of coils. The floor switches may be in the shape of a disc, which, when rotated to close the circuit, establishes also a circuit in an electromagnet behind the disc, which is thus attracted and locked. The operation of one disc thus locks all the others. When the lift is required to be controlled both from inside and outside at each floor, a combination switch may be employed in which each disc, when rotated to close the circuit, engages and moves a sliding bar behind which an electromagnet is placed to attract and lock it when the circuit is completed. When it is impossible to use floor switches, the necessary contacts may be made between pieces carried by the cage and sliding on fixed strips in the well. A safety contact is placed on each door of the well, so that the lift can only be operated when the door is closed and locked.