Abstract: A vehicle brake system for operating a spring applied, fluid pressure released brake. In order to assure that the brake is fully released before the vehicle is operated, the system requires the operator to perform two operations. He must move a manually operated hydraulic valve to the brake release position and in addition must close a normally open, momentary contact switch which actuates a second solenoid operated valve in series with the first valve to the brake release position. When pressure has built up in the brake actuator sufficiently to assure that it is fully released, a pressure sensor causes a hold-in circuit for the solenoid operated valve to be energized whereupon the operator can then release the momentary contact switch.

Abstract: A dump body vehicle module for connection to a tractor module to form a complete vehicle. The dump body module includes a horizontally disposed frame with wheels adjacent one end and a coupling portion adjacent the other end for connecting it to a tractor module. A dump body is pivotally mounted on the frame for movement between a carrying position and a dumping position and hydraulic actuators are provided to move the dump body between the two positions. A pair of leg members are pivotally mounted on the dump body for movement between three positions, one a leg storage position, another for supporting the module on the ground, and the third for supporting the dump body in an elevated position relative to the frame.

Abstract: A method for connecting together a tractor module and an implement module to form a complete vehicle . The tractor module includes a first coupling portion and a source of pressurized hydraulic fluid. The implement module includes a frame, a second coupling portion on the frame, a hydraulically operated movable structure on the frame and legs arranged to be selectively located between the hydraulically operated structure and the ground for supporting the implement module at rest. In carrying out the method the tractor module is moved adjacent the vehicle module so that the two coupling portions are in confronting relation. The source of pressurized hydraulic fluid on the tractor module is connected to the hydraulic actuators for the hydraulically operated structure on the implement module and the frame of the implement module is thereby moved relative to the hydraulically operated structure to get the two coupling portions in position to be joined.

Abstract: A retractable rock guard for the dump body of a truck, comprising a protective structure which is normally in the upright position at the front of the dump body. The protective structure is pivotally connected to the dump body but ordinarily is secured in the normal upright position by detachable connectors. However, it can be readily detached and then the protective structure can be retracted by raising the dump body to a dump position in the usual manner. The upright protective structure is constructed and arranged so that its center of mass passes through a vertical plane intersecting its pivotal connection on the dump body under these circumstances and when this occurs the proctective structure moves to a horizontally disposed retracted position on the truck body.

Abstract: An auxiliary speed control system for a vehical having an engine, a multiple ratio transmission and an operator's foot pedal for varying the engine speed. To obtain a vehicle speed which is different from any of those normally provided by the multiple ratio transmission, a device is moved into proximity to the operator's foot pedal. The device is contacted by the foot pedal when the foot pedal is depressed. When the speed of the vehicle reaches a predetermined maximum, the device acts on the foot pedal to prevent the operator from exceeding the selected speed.

Abstract: An auxiliary speed control system for a vehicle having an engine, a multiple ratio transmission and an operator's foot pedal for varying the engine speed. To obtain a vehicle speed which is different from any of those normally provided by the multiple ratio transmission, a device is moved into proximity to the operator's foot pedal. The device is contacted by the foot pedal when the foot pedal is depressed. When the speed of the vehicle reaches a predetermined maximum, the device acts on the foot pedal to prevent the operator from exceeding the selected speed.