Abstract:
In the preferred form, a vehicle leveling system having an electrically motor driven compressor that is directly communicated with a pair of fluid springs for maintaining a predetermined height relationship between the sprung and unsprung mass of a vehicle. A controller includes vehicle door operated light switches normally opened when the vehicle doors are closed. When the door is opened and closed a hold circuit is closed for a relay-operated motor energization switch. The hold circuit includes a normally closed pressure responsive switch. Following a predetermined pump-up phase a mechanically operated height controller exhausts the spring and conditions the pressure switch to open the hold circuit to deenergize the electric motor.
Abstract:
In a preferred form, this disclosure relates to a windshield wiper system wherein the direction of the rotation of an electric motor is periodically reversed to effect oscillation of a wiper through a wipe cycle having a first angular stroke when a manual switch is placed in a first on position and is reversed periodically faster to effect oscillation of the wiper through a wipe cycle having a second angular stroke which is less than the first angular stroke when the manual switch is placed in a second on position. The windshield wiper system includes relay operated switch means which is operatively connected with the motor and the manual switch for reversing the direction of rotation of the motor and a plurality of position switches which are interconnected with the relay operated switch means and actuated by a cam on the drive shaft of the motor for controlling energization and de-energization of the relay operated switch means to effect the periodic reversal of the motor.
Abstract:
In preferred form, an electronic control for an electrically operated automatic vehicle leveling system which includes a relay coil and a solenoid operated valve coil that are both connected to one terminal of a three terminal solid-state switching device in the form of a pair of transistors in a Darlington configuration. The base emitter junction of the Darlington pair is connected to a RC timing circuit through a low cost switching transistor. An undamped height sensor switch connects the charging circuit to the positive terminal of a vehicle battery and the switching transistor closes to charge a capacitor of the RC circuit from a negative reference voltage to a positive turn on voltage at the base of the Darlington pair. Following a predetermined time delay the Darlington pair is turned on to complete an energization circuit for one or the other of the coils. If the undamped switch opens before the end of a time delay cycle, the positive side of the capacitor is recharged to the battery voltage through a reset circuit to prevent normal road movements from affecting the operation of the circuit.
Abstract:
In preferred form, a fully automatic electrically operated leveling system for a vehicle having an undamped height sensing electric switch on one of a pair of air springs that operates to indicate vehicle height. An electric motor driven air compressor and electronic control circuit are mounted as a unit in a sealed storage tank along with a solenoid operated valve. The air compressor exhausts air from the springs into the tank to lower the vehicle chassis when it is unloaded. The solenoid operated valve directs air from the tank to the springs to raise the vehicle chassis when it is loaded. The electronic control circuit includes time delay means to prevent energization of the motor or solenoid in response to normal road movements of the vehicle.