Safety mechanism for preventing unintended motion in traction elevators
AssigneeDelaware Capital Formation, Inc.
InventorGordon A. Holland
Life of this patent
Estimating the term…
Abstract
A traction elevator includes a safety mechanism for preventing unintended motion of the car. A trigger, when armed, is positioned in the path of bosses on the drive sheave or another sheave, such that any unintended rotation of the sheave causes actuation of the trigger and the consequent tripping of an emergency brake. Preferably, the trigger is armed whenever the car is stopped at a landing, and is also selectively armed responsive to elevator overspeed detection.
Claims33
A traction elevator having a car, a counterweight, at least one sheave rotated responsive to motion of the car, a main friction brake for holding said car at landings and at least one additional emergency brake, mechanical catch means for holding said emergency brake in a disengaged position;
- and tripping means for tripping the catch means for actuating the emergency brake, wherein the tripping means comprise:
- engagement means on said sheave for selectively engaging a trigger for moving the trigger along a first path responsive to sheave rotation;
- a trigger moveable along said first path and also moveable along a second path between an armed position, for engaging said sheave, and a disarmed position out of engagement with said sheave;
- coupling means between said trigger and said catch means for releasing said catch means responsive to trigger movement along said first path;
- and
- control means for selectivity moving said trigger between said armed position and said disarmed position responsive to at least one elevator operating condition.
In a traction elevator having a car, a counterweight, a rotatable drive sheave, a plurality of ropes between said car and counterweight and reeved over said drive sheave, drive means for rotating said drive sheave, and a main friction brake coupled to said drive sheave for holding said car at landings, a safety mechanism for preventing unintended car motion comprising:
- a spring-loaded, emergency brake means for engaging at least one surface of said drive sheave;
- said emergency brake means including a mechanical catch means for holding said emergency brake means out of engagement with said drive sheave;
- and
- a trigger release means for tripping said catch means for releasing said emergency brake means, said trigger release means comprising engagement means on said drive sheave for selectively engaging a trigger for moving the trigger along a first path responsive to sheave rotation;
- a trigger moveable along said first path and also moveable along a second path between an armed position, for engaging said drive sheave and a disarmed position, out of engagement with said drive sheave;
- coupling means between said trigger and said catch means for tripping said catch means responsive to trigger movement along said first path;
- and control means for moving said trigger to said armed position responsive to at least one elevator operating condition.
In a traction elevator having a car, a counterweight, a governor including a sheave, rotated in response to counterweight movement, and a governor trip mechanism, and a counterweight safety actuated responsive to the tripping of said governor trip mechanism, a safety mechanism for preventing unintended car movement comprising:
- at least one boss on said sheave;
- a trigger moveable between an armed position, in the path of said boss, and a disarmed position, wherein said trigger is moved along a first path responsive to sheave rotation when in the armed position;
- coupling means between said trigger and said governor tripping mechanism for actuating said tripping mechanism responsive to trigger movement along said first path;
- and
- means for moving said trigger to said unarmed position responsive to at least one elevator operating condition indicating that car movement is intended, and for moving said trigger to said armed position responsive to at least one operating condition indicating that car movement is not desired.
Dependencies are inferred from the claim text.