Plugging defeat system for electric motors
AssigneeClark Equipment Company
InventorJames J. Bauer
Life of this patent
Estimating the term…
Abstract
A plugging defeat system for use with a reversible electric motor having a motor shaft. A slipping clutch-type mechanism is used to sense the speed and direction of the motor and to selectively open forward or reverse enabling switches when the motor reaches a predetermined speed. If operating in the forward direction, the clutch mechanism will open the reverse enabling switch, once the predetermined speed is reached, preventing motor reversal until the speed has fallen to a safe level, and vice versa.
Claims14
A plugging defeat system for use with a reversible electric motor having a shaft and a power source, comprising a motor speed and direction sensing means operatively connected to the motor shaft, a shaft member operatively connected to said sensing means for rotation therewith when the motor reaches a predetermined speed in either direction, a forward enabling switch connected in series with the control means and the motor for enabling the motor in a forward direction, a reverse enabling switch connected in series with the control means and the motor for enabling the motor in a reverse direction, and a lever means operatively connected to said shaft member for selectively opening said reverse enabling switch when the motor reaches a predetermined speed in the forward direction, and for selectively opening said forward enabling switch when the motor reaches a predetermined speed in the reverse direction.
A plugging defeat system for use with a reversible electric motor having a shaft and a power source, comprising a slipping clutch means for sensing the speed and direction of the motor, including a viscous drive unit having a housing, a driver disc connected to said motor shaft, a driven disc closely spaced from and co-axial with said driver disc, and a viscous fluid in said housing for acting on said driven disc under the force applied by said driver disc, when the motor reaches a predetermined speed in either direction, a shaft member operatively connected to said driven disc for rotation therewith when the motor reaches a predetermined speed in either direction, switch means for enabling the motor in forward and reverse directions, and a lever means operatively connected to said shaft member for selectively opening said switch means, said switch means including a normally closed forward enabling switch and a normally closed reverse enabling switch mounted on said housing on opposite sides of said lever means for transmitting electrical current from the power source to the motor when in a closed position and for preventing the respective current flow when either of said switches is opened by said lever means.
A plugging defeat system for use with a reversible electric drive motor having a shaft, a power source, and control means for operating the motor, said system comprising a slipping clutch means operatively connected to the motor shaft for rotation therewith for sensing the speed and direction of the motor, a shaft member operatively connected to said clutch means for rotation therewith when the motor reaches a predetermined speed in either direction, a forward enabling switch connected in series with the control means and the motor for enabling the motor in a forward direction, a reverse enabling switch connected in series with the control means and the motor for enabling the motor in a reverse direction, and a lever means operatively connected to said shaft member for selectively opening said reverse switch when the motor reaches a predetermined speed in the forward direction, and for selectively opening said forward switch when the motor reaches a predetermined speed in the reverse direction.
Dependencies are inferred from the claim text.