Abstract: A dozer blade attachment control system for a work machine comprises a dozer blade attachment coupled to the attachment coupler, a hydraulic circuit, and an electronic controller. The hydraulic circuit comprises a hydraulic pump, a diverter valve operable in a first position and second position, and a pressure compensated directional control valve. The electronic controller is communicatively coupled to the hydraulic circuit. The electronic circuit may modify the hydraulic circuit to one or more of a first configuration with the diverter valve in the first position for tilt, a second configuration with the diverter valve in the second position for angling, and a third configuration with the diverter valve in the second position and the pressure compensated directional control valve creating a shuttle flow path from a higher and a lower side of the hydraulic circuit for simultaneously tilting and angling.

Abstract: A skid-steer implement allows for the rotation of a tool attachment relative to the body of the skid-steer by coupling an attaching element and a rotation attachment device with a shaft and force generating devices. The slim construction of the device allows for bucket rotation while limiting the tipping load change caused by the extension of the implement.

Abstract: A work machine extending in a fore-aft direction comprising a frame and a ground-engaging mechanism, the ground-engaging mechanism configured to support the frame on a ground surface; a boom assembly coupled to the frame, the boom assembly having a pair of boom arms pivotally coupled to the frame; and an attachment coupled to a fore-section of the boom arms. The attachment may comprise a guide rigidly coupled to a fore-section of the frame; a movable member coupled to the guide, the movable member moveable relative to the frame by a pair of hydraulic cylinders, the guide restricting movement of the movable member in a non-vertical direction; and a work tool coupled to the movable member wherein actuating the pair of hydraulic cylinders engages the movable member, vertically lifting or lowering the work tool relative to the frame.

Abstract: An electro-hydraulic arrangement for controlling operation of a pair of tilt actuators of an earthmoving machine includes a housing, and a directional control valve (DCV) and a regeneration valve (RV) disposed within the housing. The DCV and the RV are coupled in selective fluid communication with one another and with rod end and head end chambers of the actuators via ports defined on the housing. When the DCV is in a first or second operative position, the RV may be positioned in a regenerative position to allow the rod end chambers of respective ones of the first and second actuators to communicate fluid to the head end chamber of the second actuator. Optionally, the regeneration valve may be positioned in a drain position to allow the rod end chambers of respective ones of the first and second actuators to communicate fluid with a drain port of the housing.

Abstract: A work machine includes a traveling undercarriage, an upper rotating structure swingably mounted on the traveling undercarriage, a cab mounted on the upper rotating structure, an attachment including multiple work elements and attached to the upper rotating structure, an end attachment attached to the end of the attachment, a first sensor configured to obtain the angles of rotation of the work elements, a second sensor configured to obtain the angle of rotation of the end attachment, and a control device configured to restrict or stop the motion of reducing a distance between the end attachment and the cab in response to determining that the end attachment has entered a predetermined region based on the outputs of the first sensor and the second sensor.

Abstract: A snow plow system for an automobile features a frame connectable to a hitch receiver, a blade movable by an electrically powered actuator between a lowered snow-clearing position a raised transport position, a power unit placed within a trunk space of the automobile, a power connection line between the power unit and the actuator, and a wireless remote operable from a passenger cabin of the automobile. The power connection line traverses through a gasket sealed space between the trunk lid and trunk walls, thereby powering the device without any modification to the automobile. A flexible member connected between the actuator and the blade is operable to raise and lower the blade in a controlled manner under operation of the actuator, while allowing the blade to momentarily trip over ground level obstructions during use. A biasing mechanism forces the blade back into the snow-clearing position once the obstruction is cleared.

Abstract: A control system for a work implement of a machine having a frame is provided. The control system includes a pair of lift cylinders operatively coupled to the work implement and configured to raise or lower the work implement with respect to the frame. Each of the lift cylinders has a rod end and a cap end. The control system includes a first cross-over line configured to fluidly communicate the rod ends to each other and a second cross-over line configured to fluidly communicate the cap ends to each other. The control system includes a cross-over valve disposed in one of the first and second cross-over lines and configured to regulate a flow of hydraulic fluid therethrough. The control system further includes a controller communicably coupled to the cross-over valve and configured to at least partially close the cross-over valve during a dump cycle of the work implement.

Abstract: A method of controlling a float function of a cylinder 25 having a first side and a second side includes connecting the second side of the cylinder to a reservoir 15; connecting the first side of the cylinder to an output of a pump 20 and to the reservoir; and supplying an amount of flow from a pump less than an amount supplied by the pump under loaded conditions. A three-position directional control valve 30 having a pump port, a reservoir port, a first cylinder port, and a second cylinder port may be provided to effectuate aspects of this method.

Abstract: A material box can telescope between larger and smaller widths to accommodate legal requirements of traveling down the road, making traveling between job sites easier and safer than conventional, unadjustable material boxes. The material box can be used in a wide configuration to plow a wider area, such as empty parking lots, cutting down work time. When cars are present, the material box can be made narrow to accommodate for the vehicles while still being an effective material moving device.

Abstract: The vehicle pulled snow scraper system is an adjustable width snow blade having a pivotally attached blade in which the forward-backward tilt of the blade is adjusted via the winch. The forward-backward tilt function also may raise and lower the bottom edge of the blade in relation to the ground surface. The invention has a two piece hitch receiver bar having two different diameters of tubing, with an impact spring between the tubes to absorb impacts when the blade catches an immovable object. The outside edges of the blade assembly extend outward to greatly increase the width of the snow plow blade as desired by the user.

Abstract: A tree shaker for harvesting fruits, nuts, and other tree-borne products includes a mobile vehicle and a boom attached to the vehicle and offset at an angle with respect to a longitudinal axis of the vehicle. A boom pivot is provided along the length of the boom. The boom pivot is lockable such that when the boom pivot is unlocked the boom is free to pivot around the boom pivot, and when the boom pivot is locked the boom is fixed around the boom pivot.

Abstract: A front lifting device for a tractor, for hitching a tool thereto and controlling the same, includes: a chassis to be attached to the bodywork of the tractor; two lower arms hinged to the chassis and including, at the end thereof furthest from the chassis, a hitching element for the tool; at least one working jack in which one of the elements, a cylinder or rod, is connected to the chassis and in which the other element, a rod or cylinder, is connected to one of the coupling arms, the working jack providing the movements of the arm or arms in a working stroke between a bottom position and a raised position; the device includes a length-adjustable linking member between one of the elements, a cylinder or rod, of the working jack and one of the parts made up of the chassis or an arm, the linking member being held in an extended state during normal working mode, and in a retracted state to enable the arm or arms to enter a retracted position.

Abstract: A vehicle is disclosed having a blade control system. The blade control system is provided to adjust the angle of a blade and to adjust the pitch of the blade. A method for adjusting the pitch of the blade is also disclosed.

Abstract: A hydraulic system for a machine is disclosed. The hydraulic system may have a tank configured to hold a supply of fluid, a pump configured to draw fluid from the tank and pressurize the fluid, a first cylinder operatively connected between a first side of a work tool and an undercarriage of the machine, and a second cylinder operatively connected between a second side of the work tool and the undercarriage of the machine. The hydraulic system may also have a first electro-hydraulic valve associated with the first cylinder and configured to selectively regulate a flow of pressurized fluid to the first cylinder independently of the second cylinder, and a second electro-hydraulic valve associated with the second cylinder and configured to selectively regulate a flow of pressurized fluid to the second cylinder independently of the first cylinder.

Abstract: In a rotation control device for rotating a rotation motor at speed in accordance with a boom raising operation amount, at the time of a combined operation for simultaneously performing a rotation action and a boom raising action, a limitation value of rotation torque in accordance with the boom raising operation amount is determined by rotation torque limitation value setting means of a controller, the limitation value serving as a rotation torque limitation value is sent to rotation speed control means, and a command value of the rotation torque is torque-limited by rotation torque limiting means.

Abstract: A track type tractor incorporates control over lift, tilt, angle and pitch into an implement control joystick. The pitch cylinder and the tilt cylinder share segments of the hydraulic circuit, and a diverter valve prioritizes pitch control over tilt control in the rare occurrence when the operator is requesting both tilt and pitch changes to the dozer blade. Angle control and pitch control may be accomplished by finger controllers incorporated into the implement control joystick. Thus, the operator can control the dozer blade in four degrees of freedom without losing contact with the implement control joystick.

Abstract: A skid steer machine having separate left and right hydraulic propulsion units includes an operating ratio change system by which the ratio of the propulsion speed of at least one of the hydraulic propulsion units versus the hydraulic flow directed to the propulsion units can be changed from at least a first ratio to a second ratio and inversely. The operating ratio change system includes an operating ratio change ECU which controls an operating ratio change device to operate in at least a first ratio configuration or a second ratio configuration, and the operating ratio change system operates in an automatic operating mode where the operating ratio change ECU selects the operating ratio according to machine parameters received by the operating ratio change ECU.

Abstract: In one embodiment a dozer blade controller, which may comprise two-way, four-way, or six-way dozer blade position control such as, for example, a two-way control only for blade tilt. In one embodiment, a pulse width control is provided for use in a blade tilt electronic controller, which controls blade tilt independently of movement of the body of the bull dozer. And in another embodiment, a pulse width controller is operable to multiply and/or divide the width of a variable pulse by a preset multiplier factor or divider factor, e.g. by 100 or dividing by 100.

Abstract: An attachment device for a skid steer loader and a method of moving materials is provided. The attachment device can have a distal end; a proximal end; at least one side member extending from the proximal end towards the distal end; a blade member positioned at the distal end and extending generally perpendicular to a direction of travel of the skid steer loader; and at least one actuator operative to move the blade member substantially in a direction of travel of the skid steer loader. Materials can be moved by the attachment device by placing the attachment device along a ground surface so that the materials are placed in front of the blade member and, while the skid steer loader remains stationary, activating the actuator to move the blade member away from the skid steer loader to push the materials.

Abstract: A hydraulic system for a machine is disclosed. The hydraulic system may have a tank configured to hold a supply of fluid, a pump configured to draw fluid from the tank and pressurize the fluid, a first cylinder operatively connected between a first side of a work tool and an undercarriage of the machine, and a second cylinder operatively connected between a second side of the work tool and the undercarriage of the machine. The hydraulic system may also have a first electro-hydraulic valve associated with the first cylinder and configured to selectively regulate a flow of pressurized fluid to the first cylinder independently of the second cylinder, and a second electro-hydraulic valve associated with the second cylinder and configured to selectively regulate a flow of pressurized fluid to the second cylinder independently of the first cylinder.

Abstract: The present invention is a road grader attachment that attaches to a bulldozer. The attachment has an elongated blade with mutually parallel side members attached to the lateral ends of the blade where each of the side members comprise a pair of spaced apart walls that house a plate movable in an up and down direction within the side member. Each of the movable plates is attached at its lower edge to a ground contacting skid.

Abstract: The present invention relates to machinery having multiple hydraulically actuated functions and, more particularly, to a control system for using a single proportional valve to control multiple hydraulically actuated functions on a piece of machinery such as a tractor or front-end wheel loader.

Abstract: A support structure for an implement lift cylinder on an earth-working machine. The support structure includes first and second implement lift cylinder supports. The first implement lift cylinder support mounts to the work machine and the second implement lift cylinder support rotatably connects thereto about a first axis of rotation. The second implement lift cylinder support receives the implement lift cylinder and allows rotational movement thereof about a second axis of rotation. The first and second axes are located within a single plane. The dual axes provide stability and adjustability of the implement lift cylinder for different angle configurations of a work implement, such as an earth-working blade.

Abstract: A method and system for controlling a vehicle comprises a torque detector for detecting a first torque level and a second torque level applied to at least one wheel of the vehicle. The first torque level is associated with a lower boom position of a boom and a second torque level is associated with an elevated boom position higher than the lower boom position. A first hydraulic cylinder is capable of raising a boom from the lower boom position to raise an available torque from the first torque level. A second hydraulic cylinder is adapted to upwardly rotate or curl a bucket associated with the vehicle when the detected second torque level meets or exceeds a second torque threshold, for example.

Abstract: A method and system for controlling a vehicle comprises a torque detector for detecting a first torque level and a second torque level applied to at least one wheel of the vehicle. The first torque level is associated with a lower boom position of a boom. An accelerometer detects an acceleration level of the boom during or after raising of the boom. A first hydraulic cylinder is capable of raising a boom from the lower boom position to raise an available torque from the first torque level. A second hydraulic cylinder is adapted to upwardly rotate or curl a bucket associated with the vehicle if the detected acceleration level of the boom is less than a minimum level during an attempt to raise the boom.

Abstract: This invention concerns a bulldozer blade having a blade tilt function effected by independently functioning lift cylinders thereby eliminating separate tilt hardware and controls.

Abstract: An optimal pump flow for both dual tilt operations and single tilt operations is obtained at low cost without increasing the complexity of the device constitution. Where there is a wish to implement a dual tilt operation, a switch is selectively operated and, in accordance with this selection result, the differential pressure set value decreases and a comparatively small flow is supplied from the hydraulic pump to the left and right tilt cylinders. Accordingly, the extension/retraction speed of the left and right tilt cylinders decreases. Where there is a wish to implement a single tilt operation, a switch is selectively operated and, in accordance with this selection result, the differential pressure set value increases and a comparatively large flow is supplied from the hydraulic pump to the left cylinder. Accordingly, the extension/retraction speed of the left tilt cylinder increases.

Abstract: A grader attachment for a skid steer utilizes the skid steer's auxiliary hydraulics to power an independent hydrostatic steering system for the grader and to control skid steer propulsion and grader blade position. The attachment mounts to the skid steer via a standard mounting connection. The auxiliary hydraulics of the skid steer are routed through a flow control valve and then through a safety valve/back pressure valve before being tapped to control the steering, blade positioning and propulsion systems of the grader. The steering and propulsion systems use a cross bar which connects to the hand control levers of the skid steer. The foot pedal used to control propulsion of the skid steer and attachment has a centering system so that the cylinder goes back to neutral when an operator's foot is removed from the pedal stopping the unit. The blade positioning system utilizes pairs of lift and angle cylinders which allow the blade to be rotated or tilted.

Abstract: The present invention is directed to a computer based control system for controlling hydraulic and electromechanical actuators on a power machine, such as a skid steer loader. The computer based control system is configured to implement a number of features to enhance certain operational aspects of the power machine.

Abstract: A control valve and feedback system has three operating states including a lifting state, a neutral state, and a lowering state. The feedback control system comprises a cylinder, a pump, a reservoir for holding working fluid, and a control valve. The control valve comprises a valve body having first and second ends with a bore defined therebetween. The valve body further comprises an inlet port, a return port, a first work port and a second work port. The inlet port, return port, and first and second work ports are defined in the valve body. The inlet port communicates with the bore and the pump. The return port is in fluid communication with the bore and the reservoir. The first work port is also in communication with the bore and the cylinder in the lifting state. The control valve is plumbed backwards so that the first work port and the second work port are in fluid communication in the lowering state. The valve also comprises a check valve disposed in the first work port.

Abstract: To provide a dual tilt control system for a work vehicle, the system being capable of using a switching valve adapted to low pressure and low flow rates and left and right tilt cylinders of the same diameter and yielding large force during pitch and dual tilt operations and requiring no piston valve. A left tilt cylinder driving hydraulic circuit and a right tilt cylinder driving hydraulic circuit for respectively supplying pressure oil from a hydraulic pump to the left and right cylinders are arranged in parallel and comprise a left tilt cylinder actuation switching valve and a right tilt cylinder actuation switching valve, respectively. In a pilot pressure signal circuit for controlling the tilt cylinder actuation switching valves, a pilot switching valve for switching a blade between the pitch operation, a single tilt operation and the dual tilt operation by means of the left and right cylinders is provided.

Abstract: An apparatus for balancing a plow including a balance circuit, a pump fluidly connected to the balance circuit, and a load sensing valve bank fluidly connected to the balance circuit in the pump, wherein the balance circuit generally includes a two-position solenoid valve, a two-position three way solenoid valve, a two-position four-way valve with detent, a counterbalance valve with reverse freeflow check, a pressure relieving valve, and a shuttle valve, the pump is a load sensing pump, and the load sensing valve bank includes a lift and lower valve.

Abstract: A slopeboard mounting linkage that raises a slopeboard while also raising and moving a fluid-powered cylinder toward the longitudinal center of the bulldozer to which the cylinder and slopeboard are attached. One end of a rod extending from the cylinder is rotatably attached to the slopeboard as is also one end of a link arm. The other ends of the cylinder and of the link arm are rotatably attached to an angled link that is rotatably attached to the back of the primary push blade of the bulldozer. And the inside edge of the slopeboard is rotatably attached to a long arm of the bulldozer.

Abstract: A method and apparatus for controlling a work implement movably connected to a work machine. An implement controller automatically controls simultaneous first and second control modes of operation assigned to the work implement. A sensor applies a signal to the implement controller indicating position of the work implement. The implement controller reverses the simultaneous first and second control modes assigned to the work implement upon detecting a predetermined movement of the work movement. The simultaneous first and second control mode assignments may also be changed by actuation of a manually actuatable device.

Abstract: The present invention is directed to a computer based control system for controlling hydraulic and electromechanical actuators on a power machine, such as a skid steer loader. The computer based control system is configured to implement a number of features to enhance certain operational aspects of the power machine. One such feature includes an operator actuable selector which provides a selector signal based on an operator input. A controller receives the selector signal and provides an auxiliary output signal to control an auxiliary valve in a selected one of an on/off mode and a proportional mode based on the selector signal.

Abstract: An extensive torsional force exerted on a vehicle body frame due to an operation of blade lift cylinders can be avoided. Determination is made to identify an occurrence condition which causes a torsional force on a vehicle body frame due to an operation of the blade lift cylinders 9. If a condition which causes a torsional force is identified, pressure oil supplied to the blade lift cylinders 9 through a lift control valve 26 is interrupted, thereby stopping the operation of the blade lift cylinders 9. Alternatively, the operation speed of the blade lift cylinders 9 may be reduced by limiting the flow rate of pressure oil supplied to the blade lift cylinders 9.

Abstract: A signal sending device 21 which stores therein proper data, such as an accelerator position and a pump output, concerning operating conditions, such as supply hydraulic pressure and flow rate, appropriate for a working attachment to be attached to the front part of a hydraulic excavator or the like is mounted on the working attachment. The body of a hydraulic excavator is provided with a controller 11 adapted to control the hydraulic sources by receiving and storing proper data sent from the signal sending device 21. The signal sending device 21 includes a ROM 31 for storing proper data for each working attachment, a CPU 32 for retrieving proper data from the ROM 31, and a data communication interface (COM) 33 for receiving command signals sent from the controller 11 of a machine body to the CPU 32 and sending to the controller 11 proper data which have been retrieved from ROM 31 by the CPU 32.

Abstract: An independent two pump system comprising an implement hydraulic pump and a steering hydraulic pump is described. The system has an inexpensive structure and the capability of preventing a construction machine from engine stalling without impairing fuel economy. When the implement hydraulic pump is actuated with the output of an engine to operate an implement attached to the construction machine, while actuating the steering hydraulic pump with the output of the engine to turn a vehicle body of the machine, the load exerted on the implement is detected and if the detected load is determined to exceed a preset value, the displacement of the steering hydraulic pump is reduced to thereby reduce the load associated with turning of the vehicle body.

Abstract: A bulldozer blade (10) is automatically reset to a predetermined excavating pitch while the bulldozer (20) is traveling backwardly after it has completed an operation of excavating, carrying, or dumping earth. The bulldozer blade (10) can be set to an excavating pitch, a carrying pitch, or a dumping pitch when excavating, carrying, or dumping earth while the bulldozer is traveling forwardly, the bulldozer blade being attached to the leading ends of frame members (15A, 15B) which are pivotally mounted on opposite sides of the vehicle body (20a) in such a manner that the bulldozer blade can swing longitudinally.

Abstract: A hydraulic drive system for the pitch cylinders (4A, 4B) of a bulldozer blade apparatus can include (a) main hydraulic pumps (30A, 30B) and an assistant hydraulic pump (31) to make up the assistant hydraulic circuit, (b) variable displacement hydraulic pumps (21A, 21B), or (c) fixed displacement hydraulic pumps (30A, 30B) and a plurality of solenoid selector valves such that the pitch cylinders can be connected in series. The assistant hydraulic pump (31) is connectable to delivery lines of the main hydraulic pumps through an assistant solenoid selector valve (32) which is controlled by an external signal. The blade (10) can be formed so that a line (14) tangential to the lower edge of the curved panel of the blade is inclined rearwardly with respect to the front face (13) of the blade edge member (12). Earth-moving work can be performed by inclining the blade (10) rearwardly by an angle (.theta..sub.

Abstract: A tilt rate compensating implement system and method utilizes first hand second sensors for sensing the position of the rod end portion of first and second implement lift jacks. A controller calculates a tilt angle of the implement based on a difference in the amount of extension of the lift jacks. An inclinometer senses an angle of the frame relative to a predetermined plane and a tilt rate sensor senses the rate of change of the frame angle relative to said plane. A corrected frame angle based on signals from the inclinometer and tilt rate sensors is combined with the implement tilt angle to provide a corrected implement tilt angle. A display device displays the corrected implement tilt angle. The controller compares the corrected implement tilt angle to the desired implement tilt angle and actuates a fluid operated system to move a tilt jack in response to a difference between the desired and corrected implement tilt angles. The tilt angle control system is particularly suited for use on a bulldozer.

Abstract: A tilt angle control system has first and second sensors for sensing the position of the rod end portion of first and second lift jacks. A controller calculates an actual tilt angle of an implement connected to the rod end portions of the lift jacks based on a difference in the amount of extension relative to a baseline. A display device displays the actual and desired tilt angles. The controller compares the actual tilt angle to a desired tilt angle and actuates a fluid operated system to move one of the first and second jacks in response to a difference between the desired and actual tilt angles. An inclinometer sensed angle of the machine relative to a horizontal plane is added to the actual tilt angle to correct the actual tilt angle of the implement. The tilt angle control system is particularly suited for use on a bulldozer.

Abstract: A single lever blade control apparatus for bulldozers that is capable of operating in three mutually perpendicular planes to activate three independent hydraulic valves controlling a bulldozer blade: up/down, tilt and angle. Movement of the bulldozer blade in an up/down motion is accomplished by the operator by pushing the single lever apparatus in the X direction, the X direction corresponding to the longitudinal axis of the bulldozer. Movement of the bulldozer blade in the tilt direction is accomplished by the operator pushing the single lever apparatus in the Y direction. Angling the bulldozer blade is accomplished by the operator rotating the handle of the single lever apparatus about the Z axis. The invention works with all variations of hydraulic valve placement.

Abstract: A quick drop valve is electrically actuated by a switch located adjacent to the implement positioning control lever. The quick drop valve is a pilot operated spring biassed valve. When the electric switch is closed a solenoid valve is energized redirecting fluid between the pilot control lines. The quick drop valve is shifted short circuiting the flow of fluid from the lift side of the hydraulic cylinder to the reservoir and redirects it to the drop side of the hydraulic cylinder for quickly dropping the working implement.

Abstract: A control mechanism for actuating multiple valve spools with a single control lever includes a frame member to which a valve assembly having multiple valve spools is assembled. A fixed shaft is mounted in a spaced parallel relationship to said valve spools, with a plurality of motion transfer devices mounted to the fixed shaft which are connected at one end to the valve spools. The other ends of the motion transfer devices are connected to an adapter which is mounted to a spherical pivot in such a way that only one of the valve spools is operated when the lever is reciprocated in a first control direction, only one other valve spool is operated when the lever is reciprocated in a second control direction, and only another valve spool is operated when the lever is twisted up to a predetermined amount. The first, second and third valve spools can be operated one at a time, two at a time or all at once.

Abstract: The material loading machine supported on the ground surface is in combination with a return to travel assembly. The combination includes a material loading machine chassis, a work implement, and at least one lift arm supported by the chassis to pivot between an uppermost position and a lower most position while supporting the work implement. Actuators pivotally raise and lower the lift arm. A lift arm position control system automatically stops the lift arm in an uppermost position when it is raised upwardly and automatically stops the lift arm in a return to travel position when it is lowered. In the return to travel position the work implement is located safely above the ground surface so that the vehicle may travel without scraping the work implement on the ground surface.

Abstract: It takes high skill to achieve maximum efficiency of construction equipment under the ever changing working conditions. The automatic implement control system helps maximize operator efficiency and convenience by allowing a predetermined angle, lift and/or tilt position of a work implement (40) to be stored in the memory of the controller (3). In operation, the implement (40) may be moved from that stored predetermined position to perform other functions. In an automatic mode, the controller (3) can return the implement (40) to that predetermined position at any time during the work cycle. A valve (15-70) is provided for selectively switching between manual and automatic modes.

Abstract: Fluid control circuits commonly control actuation of a pair of cylinders for positioning an earthmoving blade. The known circuits for providing the three operating modes of the cylinders utilize a separate control valve for each cylinder thereby making precise positioning of the blade difficult since such positioning requires coordinated control of both valves. The subject fluid control circuit includes a selector valve for determining the direction of fluid flow to and from the head end and rod ends of the tilt cylinders and a single control valve for modulating and controlling the fluid flow from the pump to the cylinders. With this circuit, the selector valve can be prepositioned in the desired position prior to actuating the control valve so that dual cylinder tip, dual cylinder tilt, and single cylinder tilt of the blade is readily controlled by manipulation of only the single control valve.

Abstract: A snow plow, designed to fit on small vehicles, is disclosed. The plow has a single point connection to the vehicle. A novel yoke mounting scheme is also disclosed, which enables the blade to be angled. The plow is operated by a pneumatic means, controlled from within the vehicle. All operating connections to the vehicle are made through a single power cord. All pneumatic lines are self contained within the plow, thereby eliminating the need for air hoses to be connected or installed on the vehicle. The plow has an upstop device that is used to block upward travel of the plow. The upstop is used to prevent the plow from obscuring the headlights of the vehicle. An uplock is also provided which acts to lock the plow blade in an non-operating position when the plow is not needed, thereby preventing the possibility of the blade dropping to the road and causing an accident. The plow is designed to be removed quickly and easily from the vehicle for storage.

Abstract: A hydraulic circuit for pitch and tilt control of a dozer blade attached to push arms on a vehicle with a pitch ram connected between one push arm and the blade and a dual actuator consisting of a second pitch ram and a tilt ram connected at their head ends. A pitch valve directs hydraulic fluid to and from the pitch rams with a diverter/combiner valve interposed therebetween to assure a flow of fluid either to said rams or from said rams at equal rates. Pilot-operated check valves hydraulically lock the pitch rams until opened by pressure directed from said pitch valve. Tilt and lift valves directs fluid pressure to and from the tilt ram and a lift ram respectively with regeneration capability for both tilt and lift functions.