Dual windshield wiper motor synchronization
First Claim
1. A windshield wiper drive comprising a pair of motors, each operating a wiper;
- a power source in electrical connection with each motor for energizing each motor to move the wiper;
wiper parking means associated with each motor for providing a circuit interruption in said electrical connection when the wiper operated by the motor is at a wiper park position, characterized by a motor synchronizer responsive to the motion of said wiper parking means to synchronize the speed of the motors comprising;
means for providing a first signal for a first time interval in response to said circuit interruption to a first motor in said pair of motors;
means for receiving said first signal and providing a second signal upon said circuit interruption to a second motor in said pair of motors following said first time interval and for preventing the production of said second signal if said circuit interruption to said second of the motors occurs during said first time interval;
means for providing a third signal for a third time interval in response to said second signal; and
means for receiving said third signal and deenergizing said first motor for said third time interval following said circuit interruption in the connection to said first motor.
1 Assignment
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Accused Products
Abstract
A windshield wiper system has two motors. Each propels its own wiper blade. A blade parking disk is attached to each motor and contains a conductive and a non-conductive segment. Electrical power supplied through the conductive segment to the motor from a "parking contact", is interrupted by the non-conductive segment, parking the blade. During normal operation, the voltage change on the "parking contact" is sensed for each motor to determine if one motor is faster than the other. If the speed difference exceeds a set level, power to the faster motor is interrupted for a preset time interval during each rotation of the parking disk, until the difference is less than the set level. The voltage on the parking contact is also sensed for the higher voltage produced if the motors are operating at high speed. If the motors are operating at high speed, the preset time interval is increased and the allowable speed difference is reduced.
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Citations
11 Claims
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1. A windshield wiper drive comprising a pair of motors, each operating a wiper;
- a power source in electrical connection with each motor for energizing each motor to move the wiper;
wiper parking means associated with each motor for providing a circuit interruption in said electrical connection when the wiper operated by the motor is at a wiper park position, characterized by a motor synchronizer responsive to the motion of said wiper parking means to synchronize the speed of the motors comprising;means for providing a first signal for a first time interval in response to said circuit interruption to a first motor in said pair of motors; means for receiving said first signal and providing a second signal upon said circuit interruption to a second motor in said pair of motors following said first time interval and for preventing the production of said second signal if said circuit interruption to said second of the motors occurs during said first time interval; means for providing a third signal for a third time interval in response to said second signal; and means for receiving said third signal and deenergizing said first motor for said third time interval following said circuit interruption in the connection to said first motor. - View Dependent Claims (2, 3, 4, 5, 6, 7)
- a power source in electrical connection with each motor for energizing each motor to move the wiper;
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8. A method for synchronizing the movement of windshield wipers in windshield wiper drive comprising a pair of motors, each operating a wiper, a power source in electrical connection with each motor for energizing each motor to move the wiper, wiper parking means associated with each motor for providing a circuit interruption in said electrical connection when the wiper operated by the motor is at a wiper park position, characterized steps of:
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installing a switch between the power source and each motor; providing a first signal for a first time interval in response to said circuit interruption to a first motor in said pair of motors; receiving said first signal and providing a second signal upon said circuit interruption to a second motor in said pair of motors following said first time interval and for preventing the production of said second signal if said circuit interruption to said second motor occurs during said first time interval; providing a third signal for a third time interval in response to said second signal; receiving said third signal and deenergizing said first motor for said third time interval following said circuit interruption in the connection to said first motor by applying said third signal to said switch between said first motor and the power source. - View Dependent Claims (9, 10, 11)
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Specification