Electronic overspeed switch
First Claim
1. An electrical speed control system for selectively connecting an accessory to an engine having a rotating electric signal producing device and a rotating shaft, said speed control system comprising:
- means connected to receive a signal from said signal producing device for producing a speed signal indicative of the rotational speed of said shaft;
signal level sensing means connected to receive said speed signal for determining if said speed signal is indicative of a speed below a preselected first level and if said speed signal is indicative of a speed above a preselected second level, and for producing an energization signal whenever said speed signal is below said first preselected threshold level, for interrupting said energizing signal when said speed signal is above said second level for maintaining said interruption of said energization signal until said speed signal falls below said first preselected level and for reestablishing said energizing signal when said speed signal again falls below said first preselected level; and
switch means connected to said accessory means, and a source of electrical power, said energization signal actuating said switch whenever said energization signal is present.
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Accused Products
Abstract
An electrical speed control system for selectively connecting an accessory to a vehicle engine having a conventional alternator driven thereby, utilizes the voltage output of the alternator stator to determine the rotational speed of the engine, and permits the accessory to be connected to the engine when the shaft speed is at or below a maximum safe engagement speed, and disconnects the accessory when the speed is above a maximum safe speed for the accessory. The speed control system further prevents reengagement of the accessory after reaching and falling below the high-speed disengage point until the rotational speed of the engine has fallen below the maximum safe engagement speed level.
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Citations
14 Claims
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1. An electrical speed control system for selectively connecting an accessory to an engine having a rotating electric signal producing device and a rotating shaft, said speed control system comprising:
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means connected to receive a signal from said signal producing device for producing a speed signal indicative of the rotational speed of said shaft; signal level sensing means connected to receive said speed signal for determining if said speed signal is indicative of a speed below a preselected first level and if said speed signal is indicative of a speed above a preselected second level, and for producing an energization signal whenever said speed signal is below said first preselected threshold level, for interrupting said energizing signal when said speed signal is above said second level for maintaining said interruption of said energization signal until said speed signal falls below said first preselected level and for reestablishing said energizing signal when said speed signal again falls below said first preselected level; and switch means connected to said accessory means, and a source of electrical power, said energization signal actuating said switch whenever said energization signal is present. - View Dependent Claims (2, 3, 4, 5, 14)
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6. An electronic speed control system for use in selectively controlling the driving of an accessory by the rotating shaft of an engine of the type employing an alternator;
- said system comprising;
converter means electrically connected to said alternator for producing a rotational speed signal which is a function of the rotational speed of said rotating shaft; first level detecting means connected to receive said rotational speed signal for producing an output signal indicating that the speed is below a first preselected threshold level; .Iadd.second level detecting means connected to receive said rotational speed signal for producing an output signal indicating that the speed is below a second predetermined threshold level;
.Iaddend.latch means connected to receive said first and second level detecting means output signals .Iadd.and .Iaddend.for producing an output signal only if said speed .[.is.]..Iadd.;
(1) remains .Iaddend.below said first preselected threshold level, (.Iadd.2) .Iaddend.has exceeded said first preselected threshold level .[.and is.]. .Iadd.but remains .Iaddend.below said second preselected threshold level .[.and.]..Iadd., or (3) .Iaddend.having exceeded said control level.[.,.]. .Iadd.thereafter .Iaddend.falls below said first preselected threshold level; andswitch means connected to receive said output signal of said latch means and connected to said accessory and an electric power source for actuating said accessory only upon the occurrence of said output signal from said latch means. - View Dependent Claims (7, 8, 9, 10)
- said system comprising;
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11. An electronic speed control system for use in selectively controlling the driving of an accessory by a rotating shaft, said system comprising:
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means connected to said rotating shaft for producing a speed signal which is a function of the rotational speed of said rotating shaft; first level detecting means connected to receive said speed signal for producing an output signal indicating that the speed is below a first preselected threshold level; second level detecting means connected to receive said speed signal for producing an output signal indicating that the speed is .[.above.]. .Iadd.below .Iaddend.a second predetermined threshold level; latch means connected to receive said first and second level detecting means output signals .Iadd.and .Iaddend.for producing an output signal only if said speed .[.is.]..Iadd.;
(1) remains .Iaddend.below said first preselected threshold level, (.Iadd.2) .Iaddend.has exceeded said first preselected threshold level .[.and is.]. .Iadd.but remains .Iaddend.below said second preselected threshold level .[.and.]..Iadd., or (3) .Iaddend.having exceeded said second level.[.,.]. .Iadd.thereafter .Iaddend.falls below said first preselected threshold level; andswitch means connected to receive said output signal of said latch means and connected to said accessory and an electric power source for actuating said accessory only upon the occurrence of said output signal from said latch means.
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12. In combination with a system for driving an accessory from an engine wherein the accessory cannot be safely connected to the engine above a first engine speed and once connected, cannot be safely operated above a second engine speed, a speed control system having a first means for selectively connecting and disconnecting an accessory to and from the engine, the engine having a rotating shaft and a signal generating device for producing a speed signal indicative of the speed of rotation of the rotating shaft;
- said speed control system comprising;
second means establishing a first signal level indicative of said first engine speed, third means establishing a second signal level indicative of said second engine speed, said first means permitting connection of an accessory to the rotating shaft only when said speed signal is less than said first signal level and causing an accessory to be disconnected from said rotating shaft when said speed signal exceeds said second signal level, said first means permitting reconnection of an accessory to the rotating shaft after an accessory has been disconnected from the rotating shaft only when said speed signal is again less than said first signal level.
- said speed control system comprising;
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13. In combination with a system for driving an accessory from an engine wherein the accessory cannot be safely connected to the engine above a first engine speed and once connected, cannot be safely operated above a second engine speed, a speed control system having a means for selectively connecting the accessory to the engine, the engine having a rotating shaft and a signal generating device for producing a speed signal indicative of the speed of rotation of the rotating shaft;
- said speed control system comprising;
first means connected to receive said speed signal from said signal generating device, second means establishing a first signal level indicative of said first engine speed, third means establishing a second signal level indicative of said second engine speed, fourth means permitting connection of an accessory to the rotating shaft only when said speed signal is less than said first signal level, and fifth means causing an accessory to be disconnected from said rotating shaft when said speed signal exceeds said second signal level, said fourth means permitting reconnection of an accessory to the rotating shaft after an accessory has been disconnected by said fifth means only when said speed signal signal is again less than said first signal level. .Iadd.
- said speed control system comprising;
Specification