US 11,897,725 B2
Adjustment of drop rate of elevator car with electromagnetic brake system
Steven M. Millett, Plainville, CT (US); Ismail Agirman, Southington, CT (US); and Amir Lotfi, South Windsor, CT (US)
Assigned to OTIS ELEVATOR COMPANY, Farmington, CT (US)
Filed by Otis Elevator Company, Farmington, CT (US)
Filed on Jul. 10, 2020, as Appl. No. 16/925,945.
Application 16/925,945 is a continuation of application No. 15/529,435, granted, now 10,745,239, previously published as PCT/US2015/061563, filed on Nov. 19, 2015.
Claims priority of provisional application 62/083,434, filed on Nov. 24, 2014.
Prior Publication US 2020/0339382 A1, Oct. 29, 2020
Int. Cl. B66B 1/26 (2006.01); B66B 5/02 (2006.01); B66B 1/32 (2006.01); B66B 11/04 (2006.01)
CPC B66B 1/32 (2013.01) [B66B 5/02 (2013.01); B66B 11/0476 (2013.01)] 14 Claims
OG exemplary drawing
 
1. 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.