Elevator overspeed protection apparatus
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorsTakashi Yumura, Kazumasa Ito
Life of this patent
Estimating the term…
Abstract
An elevator overspeed protection apparatus includes a brake apparatus which makes use of eddy currents. The brake apparatus includes a magnetic spring placed on a car in the proximity of a pickup of the elevator overspeed protection apparatus such that, when an arm of the brake apparatus is in a horizontal condition, a displacement of the pickup is prevented with a strong attracting force by the magnetic spring, but when the arm is inclined obliquely, the attracting force of the magnetic spring is prevented from acting upon the pickup. Due to the construction, the brake apparatus operates stably and with certainty and has an increased life.
Claims15
An elevator overspeed protection apparatus comprising:
- a conductor arranged and fixed along a running direction of a car in an elevator path;
- a first magnetic circuit being movable in the proximity of said conductor and having a magnetic path passing through said conductor;
- a conversion apparatus for converting a force which functions to said first magnetic circuit by eddy currents generated in said conductor when said car runs into a displacement of said first magnetic circuit in the running direction of said car;
- and
- a brake apparatus for stopping said car in response to the displacement of said first magnetic circuit in the running direction of said car obtained by conversion by said conversion apparatus,
- wherein said conversion apparatus displaces said first magnetic circuit in a small distance or does not displace said first magnetic circuit when the speed of said car is low and displaces said first magnetic circuit in a large distance when the speed of said car rises higher than a predetermined speed.
An elevator overspeed protection apparatus comprising,
- a conductor arranged and fixed along a running direction of a car in an elevator path;
- a first magnetic circuit movable in the proximity of said conductor and having a magnetic path passing through said conductor;
- a conversion apparatus for converting a force which functions to said first magnetic circuit by eddy currents generated in said conductor when said car runs into a displacement of said first magnetic circuit in the running direction of said car;
- a brake apparatus for stopping said car in response to the displacement of said first magnetic circuit in the running direction of said car obtained by conversion by said conversion apparatus;
- a keeping mechanism for keeping magnitudes of air gap portions of said first magnetic circuit on the opposite side faces of said conductor fixed;
- and
- a displacement absorption mechanism for absorbing a displacement of said first magnetic circuit in a horizontal direction with respect to said car or a balance weight on which said first magnetic circuit is provided.
An elevator overspeed protection apparatus comprising,
- a conductor arranged and fixed along a running direction of a car in an elevator path;
- a first magnetic circuit movable in the proximity of said conductor and having a magnetic path passing through said conductor;
- a conversion apparatus for converting a force which functions to said first magnetic circuit by eddy currents generated in said conductor when said car runs into a displacement of said first magnetic circuit in the running direction of said car;
- and
- a brake apparatus for stopping said car in response to the displacement of said first magnetic circuit in the running direction of said car obtained by conversion by said conversion apparatus,
- wherein said conversion apparatus includes an element for detecting physical quantity such as a force, a displacement, or a magnetic flux, which may be changed in response to the movement of the car.
Dependencies are inferred from the claim text.