CLUTCH ASSEMBLY FOR ELECTRICALLY OPERATED RETRACTABLE JACK

摘要

An electrically operated retractable jack for leveling a vehicle. The jack is automatically retractable from a vertical position into a horizontal stowage position under the vehicle. The jack may be operated individually or a plurality of jacks may be used in leveling the corners of a vehicle. The jacks may be raised and lowered by control switches mounted inside the vehicle without the need of the operator getting outside the vehicle. The jack makes use of a torque limiting clutch which prevents overloading of the motor and prevents the jack from locking up during raising or lowering of the jack. The clutch comprises a drive gear having several spaced valleys in one of its flat surfaces and a drive plate with apertures aligned with the valleys. Balls disposed in the apertures extend into the valleys and are spring biased into the valleys. The biasing force determines the torque which can be transmitted because when this predetermined torque is reached the balls roll freely into and out of the valleys.