Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
145 words
A braking apparatus for electric motors subject to overhauling loads comprising: an alternating current power source; an electric alternating current motor having a normal operating speed; a control system for starting, stopping, and controlling the direction and limit of travel of said motor; and a fixed capacitor permanently connected to at least one of the motor windings such that at any time power is removed from said motor, said capacitor being selected in cooperation with the residual magnetic field of the motor stator windings and their associated impedance characteristics to effect a resonant condition causing said motor to become self-excited and to develop braking torque upon continued rotation of said motor above a speed substantially below normal operating speed for the purpose of limiting said speed with power off and said capacitor and said motor windings alone cooperate to effect running performance of said motor.
Claim 2
Dependent Claim
145 words
A braking apparatus for electric motors subject to overhauling loads comprising: an alternating current power source; an electric alternating current motor having a normal operating speed; a control system for starting, stopping, and controlling the direction and limit of travel of said motor; and a fixed capacitor permanently connected to at least one of the motor windings such that at any time power is removed from said motor, said capacitor being selected in cooperation with the residual magnetic field of the motor stator windings and their associated impedance characteristics to effect a resonant condition causing said motor to become self-excited and to develop braking torque upon continued rotation of said motor above a speed substantially below normal operating speed for the purpose of limiting said speed with power off and said capacitor and said motor windings alone cooperate to effect running performance of said motor.
Claim 3
Dependent Claim
29 words
The apparatus of claim 1 wherein: said electric motor is of the single phase induction motor type and wherein said capacitor further effects the starting torque of said motor.
Claim 4
Dependent Claim
24 words
The apparatus of claim 2 wherein: the capacitor effects a starting torque in the range of 125 to 175 percent of normal running torque.
Claim 5
Dependent Claim
33 words
The apparatus of claim 1 wherein: the dynamic braking effect of said capacitor is sufficient to allow the elimination of plugging limit switches in the hoist limit control without increase in hoist headroom.
Claim 6
Dependent Claim
69 words
The apparatus of claim 1 wherein: said electric motor is of the single phase alternating current induction type of the permanent split capacitor design; and said capacitor is designed to effect a starting torque of between 125 to 175 percent of normal running torque and sufficient braking to eliminate the necessity to plug the motor at limit stops and the need for supplimentary braking beyond the normal motor brake.
Claim 7
Dependent Claim
15 words
The apparatus of claim 1 wherein: said electric motor comprises a polyphase induction motor type.
Claim 8
Dependent Claim
47 words
The apparatus of claim 6 further comprising a means to resist rotation of the motor opposite to the intended direction in case of loss of power on one phase of the polyphase supply and whereby the apparatus can be utilized when necessary from a single phase supply.
Claim 9
Dependent Claim
22 words
The apparatus of claim 6 wherein: said capacitor is permanently connected across a single phase of the windings of said polyphase motor.
Claim 10
Dependent Claim
34 words
The apparatus of claim 6 wherein: the electric drive motor is designed with reduced starting torque of 125 - 175 percent of normal rated running torque for the specific purpose of preventing dangerous overloading.