Control system for controlling the engagement of a pressure-operated actuator
AssigneeBorg-Warner Corporation
InventorFred D. Sturges
Life of this patent
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Abstract
A smooth, optimum engagement of a pressure-operated actuator, such as a brake or clutch, is obtained by producing a pulse width modulated signal, having a gradually changing duty cycle, which is then used to control a three-way on/off solenoid valve to which is supplied pressurized fluid such as air. The solenoid valve is rapidly switched between pressure in and exhaust out in accordance with the changing duty cycle in order to develop a gradually increasing fluid pressure for application to the actuator.
Claims12
A control system for controlling the rate of engagement of a pressure-operated actuator, comprising:
- means for developing a pulse width modulated signal having a duty cycle which gradually changes in a constant direction;
- means responsive to said pulse width modulated signal for producing a gradually increasing fluid pressure;
- and means for applying the gradually increasing fluid pressure to the actuator to effect a smooth engagement thereof.
A control system for controlling the fluid pressure applied to a pressure-operated actuator to optimize the rate of engagement of the actuator, comprising:
- a pulse width modulation circuit for developing a pulse width modulated signal;
- control means for controlling said pulse width modulation circuit to gradually change the duty cycle of the pulse width modulated signal in a constant direction;
- means responsive to said pulse width modulated signal for producing a gradually increasing fluid pressure;
- and means for applying the gradually increasing fluid pressure to the actuator to effect a smooth engagement of the actuator.
Dependencies are inferred from the claim text.