Centrifugal brake
AssigneeJohnson Service Company
InventorsRoger V. Hajny, Robert J. Pirkey
Life of this patent
Estimating the term…
Abstract
The present invention provides a centrifugal brake which, according to one aspect of the invention, has a center hub from which extend flex members terminating in tabs extending from the flex members. Disposed on the opposite side of each flex member from the tab, is a friction portion. The friction portion is brought into contact with a braking surface when the centrifugal brake is rotated at sufficient speeds so that the centrifugal force acting on the tabs causes the flex members to bend and bring the friction portions into contact with the braking surface thereby resisting further acceleration of the centrifugal brake.
Claims18
A centrifugal brake which can be mounted on a rotatable shaft for cooperation with a stationary braking surface, comprising:
- a center hub configured for attachment to the rotatable shaft;
- at least one flex member having a proximal end and a radially distal end, wherein said proximal end is coupled to said hub and said distal end is disposed a spaced distance from said hub;
- a tab extending at an angle from said radially distal end of each of said flex members and generally away from said stationary braking surface;
- and
- a friction portion affixed to said tab and disposed proximate the braking surface, wherein when said centrifugal brake rotates at sufficient speed, the centrifugal force acting on said tab causes said flex member to bend towards the braking surface, bringing said friction portion into contact with the braking surface, thereby creating a resistance to rotation of said centrifugal brake.
A centrifugal brake for mounting on a rotatable shaft and for cooperation with a stationary braking surface, comprising:
- a hub having a bore through which the shaft extends, said hub being affixed to the shaft;
- at least one flex member affixed to said hub, each flex member extending radially outward from said hub, each flex member ending at a radially distal end;
- a tab extending from said distal end of each flex member in a direction away from the stationary braking surface;
- and
- a friction portion disposed on said tab and located adjacent the stationary braking surface, wherein when said centrifugal brake rotates at sufficient speed, the centrifugal force acting on said tab caused said flex member to bend towards the stationary braking surface bringing said friction portion into contact with the stationary braking surface, thereby creating resistance to rotation of said centrifugal brake and the shaft to which it is attached.
A centrifugal brake assembly for use in a rotary electric actuator, the actuator having an electric motor connected to an actuator collar via a power transmission, and a spring return connected to the power transmission for returning the actuator collar to a fail safe position when power to the actuator is interrupted, said centrifugal brake assembly comprising:
- an electric motor shaft extending from the electric motor and connected to the power transmission for rotating the power transmission;
- a stationary braking plate through which said electric motor shaft rotatably extends;
- and
- a centrifugal brake affixed to said electric motor shaft in proximity to said braking plate, said centrifugal brake including a flex member extending radially outward from said electric motor shaft, a tab extending out of said flex member away from said brake plate, and a friction portion having less mass than said tab and extending out of said flex member towards said brake plate, wherein when power is interrupted and the spring return accelerates said electric motor shaft and said centrifugal brake to sufficient rotational speeds, the centrifugal force acting on said tab causes said flex member to bend, bringing said friction portion into contact with said brake plate, thereby resisting any further acceleration of said electric motor shaft.
Dependencies are inferred from the claim text.