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US 11,897,725 B2Granted
Adjustment of drop rate of elevator car with electromagnetic brake system
AssigneeOtis Elevator Company
InventorsSteven M. Millett, Ismail Agirman, Amir Lotfi
Life of this patent
Estimating the term…
Abstract
A braking system for an elevator includes an electromagnetic brake operably connected to an elevator car, and a control circuit operably connected to the electromagnetic brake. The control circuit includes a switching mechanism configured to selectively modify a rate of engagement of the electromagnetic brake to selectively modify a rate of deceleration of the elevator car. The switching mechanism has a first position, a second position and a third position, to selectively modify the rate of engagement.
Claims14
A braking system for an elevator comprising:
- an electromagnetic brake operably connected to an elevator car;
- and
- a control circuit operably connected to the electromagnetic brake, the control circuit including a switching mechanism configured to selectively modify a rate of engagement of the electromagnetic brake to selectively modify a rate of deceleration of the elevator car;
- wherein the switching mechanism has a first position, a second position and a third position, to selectively modify the rate of engagement;
- wherein in the first position the switching mechanism closes on a first pathway to direct electrical current along the first pathway having a snubber diode to slow dissipation of current in the control circuit in an event of a loss of AC power to the control circuit;
- and
- wherein in the second position the switching mechanism closes on a second pathway to direct directs electrical current along the second pathway arranged in parallel to the first pathway and including a snubber diode and a resistor;
- wherein in the third position the switching mechanism is in an open position such that deceleration is not delayed.
5 more elements
A method of engaging an electromagnetic brake for an elevator system comprising:
- detecting one or more operational characteristics of the elevator system;
- selecting a first position, a second position or a third position of a switching mechanism disposed at a brake control circuit depending on the one or more detected operational characteristics;
- flowing electrical current through one or more components of the brake control circuit, depending on the position of the switching mechanism, to determine a rate of engagement of the electromagnetic brake;
- and
- stopping a flow of electrical current through the brake control circuit, thereby causing engagement of the electromagnetic brake;
- wherein in the first position the switching mechanism closes on a first pathway to direct electrical current along the first pathway having a snubber diode to slow dissipation of current in the control circuit in an event of a loss of AC power to the control circuit;
- and
- wherein in the second position the switching mechanism closes on a second pathway to direct electrical current along the second pathway arranged in parallel to the first pathway and including a snubber diode and a resistor;
- and
- wherein in the third position the switching mechanism is in an open position such that deceleration is not delayed.
7 more elements
An elevator system comprising:
- a hoistway;
- an elevator car movable along the hoistway;
- a machine operably connected to the elevator car to urge movement of the elevator car along the hoistway;
- an electromagnetic brake operably connected to an elevator car;
- and
- a control circuit operably connected to the electromagnetic brake, the control circuit including a switching mechanism configured to selectively modify a rate of engagement of the electromagnetic brake to selectively modify a rate of deceleration of the elevator car;
- wherein the switching mechanism has a first position, a second position and a third position, to selectively modify the rate of engagement;
- wherein in the first position the switching mechanism closes on a first pathway to direct electrical current along the first pathway having a snubber diode to slow dissipation of current in the control circuit in an event of a loss of AC power to the control circuit;
- and
- wherein in the second position the switching mechanism closes on a second pathway to direct electrical current along the second pathway arranged in parallel to the first pathway and including a snubber diode and a resistor;
- and
- wherein in the third position the switching mechanism is in an open position such that deceleration is not delayed.
9 more elements
Dependencies are inferred from the claim text.