Abstract: A material handling vehicle is provided which includes a lower truck chassis and an upper material handling structure pivotally supported by the lower chassis, all functions of which vehicle are driven by a single engine. The material handling vehicle is controllable from a main truck cab on the truck chassis or from an upper operator's cab mounted on the upper structure. The single engine provides highway travel power and power to all excavator functions, while the vehicle, including remote travel and implement manipulation capabilities, may be controlled from the upper operator cab. The main engine, when used for over-the-highway travel, powers the driven wheels through a manual transmission in a conventional manner.

Abstract: A priority biased load sense hydraulic system for hydraulic excavators is provided. The hydraulic system includes first and second variable flow pumps which are coupled in load sense arrangement. The first pump is coupled to a first valve bank having a first valve section having a main spool and a compensator spool having an orifice therein, a second valve section having a main spool and a compensator spool having an orifice therein, and third and fourth valve sections each having a main spool and a compensator spool. The second pump is connected to a second valve bank. The second valve bank includes a first section having a main spool and a compensator spool having an orifice. A second valve section having a main spool and a compensator spool having an orifice and a third valve section. The compensator spools in the first and second valve banks serve to prioritize hydraulic fluid flow through the valve banks thereby affectively prioritizing the hydraulic functions receiving hydraulic fluid flow.

Abstract: A material handling vehicle is provided which is capable of operation on the highway, off-road and on railroad tracks. The vehicle includes a lower truck chassis having an engine and a first operator's cab and an upper structure which includes an upper structure operator's cab and a material handling implement. In the travel mode of operation, the engine is directly connected to the torque converter of a powershift transmission to provide a rotational output to the drive wheels. In the off-road or remote operating mode of the excavator, the transmission is controlled so as to prohibit the connection between the torque converter and the transmission gears. However, a power take-off on the transmission is coupled to a hydraulic pump which provides hydraulic fluid under pressure to a hydraulic motor which, in turn, may provide rotational power to a secondary input to the transmission to provide drive power.

Abstract: Extended-reach lift apparatus for remote accessing of low-clearance areas is provided. The apparatus includes a vehicle whose frame supports a vertically pivotable telescoping boom which is elevatable by means of hydraulic rams. An extended tilt head is provided on the free end of the boom which includes parallel upper and lower link members of equal length. A work implement support having a discrete work implement tilting cylinder is attached to the remote ends of the upper and lower links of the tilt head. A hydraulic cylinder extending between the boom and the lower link of the tilt head provides separate tiltability of the tilt head while the design of the tilt head mechanically assures the maintenance of the attitude of the work implement without requiring additional hydraulic compensation during such tilting.

Abstract: Apparatus for providing additional effective length to the telescoping boom of a material handling apparatus is provided. A pivotable boom cradle is supported on an upper structure of the material handling apparatus. The boom cradle pivotally supports the base boom section by means of front and rear cradle arms. Front and rear straps are provided to attach the boom to the cradle arms. In addition, front stop blocks are provided intermediate the length of the base boom section while rear stop blocks are provided adjacent the trailing end thereof. In normal operation, bolts secure the front stop blocks to the front portion of the boom cradle. When it is desired to operate with an additional entended length of the boom, the material handling implement is imbedded in the ground, the bolts securing the front stop blocks to the boom cradle are removed and the bolts securing the front and rear straps to their respective cradle arms are loosened.

Abstract: Apparatus for stabilizing a material handling vehicle during implement manipulation is provided. Dual hydraulic cylinders are provided on each side of the vehicle intermediate the vehicle's frame and a spring-biased solid axle. A lockout valve having a pneumatically actuated check valve in fluid communication with one-way check valves and flow restriction valves corresponding to each of the upper and lower ports of the respective hydraulic cylinders is mounted on the vehicle's frame and is in fluid communication with a reservoir of hydraulic fluid. When the vehicle is not caused to travel, the pneumatically actuated check valve is closed allowing no hydraulic fluid flow between the ports of the hydraulic cylinders and thereby locking the then-present fluid in each of the chambers of the hydraulic cylinders which prevents the movement of the pistons thereof and, hence, any displacement of the front axle relative to the vehicle frame.

Abstract: A material handling vehicle is provided which includes a lower truck chassis and an upper material handling structure pivotally supported by the lower chassis, all functions of which vehicle are driven by a single engine. The material handling vehicle is controllable from a main truck cab on the truck chassis or from an upper operator's cab mounted on the upper structure. The single engine provides highway travel power and power to all excavator functions, while the vehicle, including remote travel and implement manipulation capabilities, may be controlled from the upper operator cab. The main engine, when used for over the highway travel, powers the driven wheels through a power shift transmission in a conventional manner.

Abstract: A remote controller for the transmission of a material handling vehicle having a lower chassis on which is mounted a truck cab, an engine and the transmission and which pivotally supports an upper structure including an upper cab and a material handling implement is provided. A three-way rocker switch is mounted on a joystick in the upper cab and is connected via a single control wire through a single slip ring to the main shift controller. The rocker switch is normally biased with a reference voltage which, when the switch is actuated to its other positions is either increased or grounded. First and second comparators in the main shift controller monitor the voltage in the control wire and cause a counter to increase or decrease the number stored in its memory on the basis of increases or decreases in the control wire voltage. The main shift controller then outputs a signal to the shift solenoids of the transmission based on the number stored in the counter.

Abstract: An inching system for use in a vehicle for performing work which permits the vehicle to be moved at reduced speeds while maintaining sufficient engine speed, and therefore, sufficient hydraulic fluid flow and pressure for actuating the work-performing apparatus. The inching system includes a control valve for controlling the amount of hydraulic fluid which a forward-reverse valve is able to direct to the rear drive means, an orifice through which hydraulic fluid flows from a source of hydraulic fluid to the control valve to restrict the flow of fluid to a level below that of the flow to the work-performing apparatus, and a variable inching valve for metering hydraulic fluid from the control valve so that fluid pressure available to the forward-reverse valve, and in turn, to the rear drive means, is progressively reduced. A pedal is provided in the cab of the vehicle to selectively actuate the variable inching valve to effect inching control.

Abstract: A remote driving system (40) for use on a material handling vehicle (10) having a rotatable upper structure (12) including means for driving said material handling vehicle (10) through powershift transmission. A hydraulic power supply (50) is provided on the upper structure (12) and the output of which is controlled by an operator in the excavator cab (32) to be supplied to the hydraulic motor (44) supported on the main chassis (26). The hydraulic motor (44) is connected to provide power input to the automatic transmission (34) for forward or reverse driving of the vehicle (10). Means are provided for selecting the gear ratio set in the powershift transmission (34) from the excavator cab (32). Hydraulic motor (44) drives a pump (68) which provides pressurized automatic transmission fluid for lubricating the powershift transmission (34) and provides power for operating selected clutches in the powershift transmission (34).