Abstract: An implement having a rotary flow divider controlling fluid to and from at least two independent hydraulic rams for raising and lowering the implement in a level manner. A counter monitors the revolutions of the flow divider and actuates an electric circuit which controls solenoid valves to stop the implement at the proper height. A cab mounted adjustable count selector is provided to adjust the desired height of the implement.

Abstract: A pumping unit pumps two wells, simultaneously, to save energy and space, weight of one rod string offsetting weight of the other string.

Abstract: In a press with two parallel, spaced apart multiple-acting cylinders that have their respective pistons connected to end portions of a beam to which a bending or forming tool is secured, the cylinders are respectively fed from effectively separate pressure fluid sources providing equal pressures and flow rates. For synchronization of piston extension through an initial rapid advance, the chamber of each cylinder that is normally pressurized for retraction of its piston is connected in feedback relation to the pressure fluid source for the other cylinder, so that fluid expelled from a leading cylinder augments the fluid supply to the lagging one. The system further comprises a pair of sensors, one for each beam end, and a synchronizing bleed-off valve for each sensor.

Abstract: Prior art interrupted series type load sensitive hydraulic systems have not had the capability of both providing full speed simultaneous vehicle cornering and implement correction while preventing the same when the implements are operating at a high pressure level, and preventing low torque motor stall. Herein, an input flow path (22) delivers pressurized fluid flow from a source (12) to a first priority (steering) circuit (14). A series flow path (24) delivers the output flow from the circuit (14) to an implement circuit (16). A parallel flow path (26) delivers a portion of the flow from the source (12) to the implement circuit (16). A valving structure (42) is in the series flow path (24). The valving structure (42) is opened in response to load pressure in the implement circuit (16) being at or below a selected value and is closed in response to the load pressure in the implement circuit being above said value.

Abstract: A flow control valve assembly for controlling first and second reversible fluid motors for series or parallel operation has a direction control secton and a torque control section provided in a single valve body. The valve body has first, second, and third supply ports selectively pressurizeable by the direction control section and connected to a torque control bore in the torque control section. First and third function passages extend from the torque control bore and are connectible to the first fluid motor, and second and fourth function passages extend therefrom and are connectible to the second fluid motor. A grooved, torque control spool is disposed in the torque control bore for sliding from a series operating position wherein the grooves connect the first port to the first function passage, the second function passage to the third function passage, and the fourth function passage to the second and third ports.

Abstract: A drill boom arrangement comprises a boom proper that is universally pivotably carried by a boom support. The boom carries a feed beam for a rock drill. The boom is swingable on the support by means of two hydraulic cylinders forming a tripod and the feed beam is swingable on the boom by means of two hydraulic cylinders forming another tripod. One of the boom swinging cylinders (17) is coupled in series with one of the feed beam swinging cylinders (28) and these two cylinders are actuated by means of a common direction control valve (58). The boom swinging cylinder (17) can be short-circuited so that the feed beam can be swung upon actuation of the direction control valve (58) while the boom is arrested. The other boom swinging cylinder (16) is coupled in series with the other feed beam swinging cylinder (29) to a common direction control valve (57) in the same way. A joy-stick (59) is coupled to the two direction control valves (57, 58) through pilot valves and pilot lines (64-67).

Abstract: Apparatus and method for cutting and feeding foliage material from a stack, the apparatus comprising a wheeled vehicle, for example a wagon pulled by a tractor, capable of being displaced along the ground, a tiltable bed thereon disposed in a parallel position between ground engaging wheels and a powered conveyor so that a stack of foliage may be loaded onto the bed from a position on the ground (or unloaded from the bed back to the ground) and also may be successively advanced along the conveyor bed to provide an overhang beneath and forward of a rotating angularly disposed variable cutter which travels horizontally and then vertically downward in a zig-zag pattern to successively cut slices of foliage from the overhang of the stack.

Abstract: A tree shear head includes a shear, a grapple tong and an accumulator tong which are positioned by respective double-acting hydraulic actuators controlled by selectively actuatable solenoid-operated valves such as to place the shear head either in a non-accumulate mode wherein both tongs operate concurrently to grasp and release trees one-by-one or an accumulate mode wherein the tongs are individually operated in a sequence resulting in the accumulation of a plurality of cut trees.

Abstract: A device for varying the angular setting of the blade of an earthmoving vehicle by means of a pair of double acting hydraulic cylinders in which only one of the cylinders receives pressure direct from a pump. The piston of that cylinder acts on one end of the blade and at the same time transmits pressure fluid through a hydraulic circuit to the piston of the other cylinder acting on the other end of the blade whereby the two pistons move in opposite directions. The hydraulic circuit includes a control valve for reversing the direction of movement of the pistons, the same cylinder being pressurized by the pump in both directions of movement of the pistons. Pressure fluid leakage loss compensating means are provided in each piston.

Abstract: A pilot assembly for switching the fluid supply valve of a hydraulic pump is actuated by the pressurized hydraulic fluid which operates the hydraulic pump. The hydraulic pump includes a main cylinder, a main piston within the main cylinder, and a main valve for supplying pressurized hydraulic fluid to the rear end of the main cylinder for driving the piston forwardly. The pilot assembly includes a pilot cylinder and a pilot spool within the cylinder. A first hydraulic conduit connects one end of the pilot cylinder to the front end of the main cylinder, and a second hydraulic conduit connects the other end of the pilot cylinder to the main cylinder at a position spaced rearwardly from the front end of the main cylinder. When the main piston passes forwardly of the second hydraulic conduit, the pressurized hydraulic fluid in the main cylinder moves the pilot spool, and pressurized hydraulic fluid is allowed to flow to the main valve to switch the main valve.

Abstract: A synchronizer is provided for synchronizing the movements of two hydraulic actuators. The synchronizer consists of a two-piston pump which supplies hydraulic fluid to both actuators. The two pistons are mechanically connected so as to move simultaneously through equal distances, and on each complete stroke of the pump, each actuator receives fluid from both cylinders of the pump, so that both actuators receive precisely equal amounts of fluid.

Abstract: A priority system has a valve assembly which has an inlet, first and second outlets, and apparatus for controllably limiting fluid pressure at the first outlet to a preselected maximum value by controllably communicating the second outlet with the inlet. The priority system has a fluid reservoir, a work element and control apparatus connected to the work element, second outlet and reservoir which receives fluid from the second outlet and passes the fluid to the fluid reservoir or work element.

Abstract: A power piston apparatus, comprising two or more double acting hydraulic piston drive means in which the cross-sectional areas of the pistons are identical and the cylinder spaces or chambers of which are hydraulically interconnected in crossed fashion above and below the pistons in the case of two cylinders, while being connected in series in the case of more than two cylinders having separately closed oil spaces of identical volumes, with each such oil space being connected to a positive-pressure oil supply through check valves for replenishing the leakage oil, and wherein said piston drive means have associated therewith metering cylinders with a coaxial and/or parallel direction of stroke, i.e. with mechanical connections between the ends of the piston rods.

Abstract: An improved master cylinder in which a pair of orifices extend through the cylinder wall and means is provided on the exterior of the cylinder to permit fluid communication therebetween. The orifices are located near the end of the cylinder to permit restricted flow around the piston in the master cylinder when it is near or at the end of its stroke to cause both the master and slave piston to complete their strokes and at substantially the same time. A similar pair of orifices and an exterior communication means at the other end of the cylinder provides for re-phasing during piston movement in the opposite direction.

Abstract: A hydraulic positioning drive with a physically separated work cylinder which is connected via pressure oil lines, comprises a follow-up cylinder mounted at the positioning drive or in the immediate vicinity thereof, of the same type and the same volume as the work cylinder, which is hydraulically connected in series with the latter, so that its piston moves synchronously with that of the work cylinder. The piston position of the follow-up cylinder is sensed electrically and used as the positioner position. For synchronizing, both cylinders are connected in parallel from time to time and their pistons are run into the end positions.

Abstract: A hydraulic system for a vehicle having an open center type braking booster and the other hydraulic operating system e.g. power steering having open center type valve mechanism, both being in fluid communication with a discharging port of an engine driven pump for receiving input fluid flow through a flow divider.The invention provides, at an early stage of the braking operation, means for fluid communication between the discharge port of the power steering system and the inlet port of the booster other than communication between the discharging port of the flow divider and the inlet port of the booster.

Abstract: Compensating cylinders are provided for pairs of transverse steering linkages connecting pairs of tractors that steer in unison on opposite sides of a main frame of a heavy construction machine whereby the steering linkages automatically extend and retract to accommodate the changes in length imposed by changes in the slope or off-sets in the grade being negotiated by the machine.