Abstract: Provided is a hill holder system operative to prevent a vehicle such as a truck having a fluid operated brake system from rolling backward down an incline or to assist an operator in braking when descending an incline. The system utilizes a control signal (C) provided by a central processing unit (10) operative to instruct a brake control valve (22) to close the brake balve exhaust port(s) (27) to maintain the brakes in an engaged condition whenever a selected speed condition such as vehicle ground speed is below a predetermined value. In other embodiments, selected vehicle drive train conditions such as either or both throttle and clutch position are processed in combination with the selected speed signal to effect braking in the manner desired.

Abstract: The tangs of the clutch and brake springs of a wrap spring clutch/brake unit are connected to separate sleeves which form the control collar of the unit. The sleeves are normally coupled for rotation in unison by an internally splined ring which may be slid to a released position permitting relative rotation of the sleeves for purposes of adjusting the torsional differential of the springs.

Abstract: A vehicular control mechanism is known that incorporates a steering assembly swingable about an upstanding axis in either direction from a central NEUTRAL position. Even if the transmission is not powerably driving an associated cross drive mechanism the angular displacement of the steering assembly away from NEUTRAL could cause an input to the cross drive and an undesirable movement of the vehicle under some circumstances. To obviate this, an indexing device is provided that is responsive to the movement of an actuating lever pivotally mounted on a steering assembly between BRAKE-OFF and BRAKE-ON positions. The vehicle frame defines an indexing pocket, and an elongate locking element is reciprocally mounted on the steering assembly and interconnectable with the pocket when the steering assembly is angularly positioned in NEUTRAL.