Patent GB-190201548-A (GB)
Title: Improvements connected with Elevators or Lifts.
Filed: 1902-01-20
Granted: 1902-04-17
Abstract: 1548. Otis Elevator Co., [Otis Elevator Co.]. Jan. 20. Motors, controlling. -Relates to electrically-controlled lifts, and consists primarily in providing pneumatic instead of electric connections between the floors and car and the controlling- apparatus proper of the motor, and includes an improved floor r controller designed to minimize arcing and to allow of adjustment of the parts so as to ensure the car stopping on a level with the floors. Fig. 1 is a diagram of most of the apparatus. A represents the motor, B the car, C the winding-drum, and E, F a reversing- switch operated for downward and upward movement by relays D', U' respectively. The switches 1<b>, 2<b>, &c. of the floor controller are adapted to be closed by means of pneumatic connections operated by push-buttons 1<1>, 2<1>, 3<1>, 4<1> on the car and corresponding buttons at the different floors. On the car there are in addition two pneumatic buttons 5<1>, 6<1>, the latter when pressed opening an emergency switch 8 to stop the motor, and the former closing the normally-open switch 11, 12 of the "safety" circuit. The motor-controlling circuit starts from the positive main at 7 and enters the negative main at 17, and between the point 7 and the switch 10 it includes the switch (not shown) controlled by the well doors, and the switch 8. Starting from the switch 10 the "safety "circuit includes the contacts 11, 12, electromagnets 13, 15, one winding 16 of the "safety" electromagnet, and the resistance R<4>. When, by pressing the button 5', this circuit is made, the normally-open switch 21, 22 is closed so that, on now pressing one of the buttons, say 1<1> on the car, a circuit parallel with the "safety" circuit is made through the switch 21, 22, point 24, normally-closed switch 20, switch 1<b>, corresponding solenoid s, bar s', and wire s<2> to the point 17. The core t of the solenoid s thus energized is consequently depressed into contact with the sliding insulated bar J, which is geared to have a travel proportioned to the travel of the car, and a third circuit is thus made from the point 26, through the second winding 25 of the magnet S, relay D', bar J, core t, solenoid s, bar s', and wire s' to the point 17. The electromagnet S is now strong enough to open the switch 20, so that all the switches 1<b> &c. are cut out and no interference with the motion of the car is possible by pressing any of the floor buttons. The bar J is divided by an insulation block J<1>, and, on this block reaching the core t which has been depressed, the relay circuit is broken and the motor stopped. The winding 16 in the " safety " circuit, which is still closed, is, however, strong enough to keep the switch 20 open so that interference with the car is still impossible, until the switch 8 or the well-door switch is opened. Normally the contacts 11, 11<1> of the switch 10 are closed, so that on pressing one of the floor buttons the circuit through the corresponding solenoid s is made through the contacts 11, 11<1> and switch 20, the " safety" circuit being open, so that, although the switch 20 is open while the motor is running, it closes again as soon as the motor stops. The block by which contact is made between the core t and the bar J is carried by an arm of the core. In case a core should fail to rise when the insulation block J<1> comes under it, a projection is provided on the carrier of the bar J, adapted to positively lift the core. Each core t can turn. easily in its solenoid to an extent limited by stops engaging the arm of the core, so that during part of the. period of contact of the arm and the bar J these two move together. By adjusting this part of the contact period by the stops, the total time of contact can be adjusted so as to ensure the correct stoppage of the car at the floor.