Abstract: A machine includes an engine and a governor operable to control an operating speed of the engine along a first droop curve such that the operating speed is a function of an operating load of the engine. The first droop curve includes a first region that defines a first slope, a second region that defines a second slope different from the first slope, and a transition point located at an intersection of the first region and the second region. The machine further includes a controller in communication with the governor. The controller is configured to determine an average operating load of the engine over a predetermined time period, adjust the location of the transition point based at least in part on the average operating load to create a second droop curve, and operate the engine based on the second droop curve.

Abstract: A machine includes an engine and a governor operable to control an operating speed of the engine along a first droop curve such that the operating speed is a function of an operating load of the engine. The first droop curve includes a first region that defines a first slope, a second region that defines a second slope different from the first slope, and a transition point located at an intersection of the first region and the second region. The machine further includes a controller in communication with the governor. The controller is configured to determine an average operating load of the engine over a predetermined time period, adjust the location of the transition point based at least in part on the average operating load to create a second droop curve, and operate the engine based on the second droop curve.

Abstract: A vehicle cooling system includes a fan, a first heat exchanger, an upper heat exchanger and a lower heat exchanger. The first heat exchanger is spaced apart in front of the fan. The upper heat exchanger is positioned between a top portion of the fan and a top portion of the first heat exchanger. The lower heat exchanger is positioned between a bottom portion of the fan and a bottom portion of the first heat exchanger. A structural frame supports the first, top and lower heat exchangers, and the frame forming a fan shroud which surrounds the fan.

Abstract: An improved hydraulic circuit for automatically sequencing a pair of hydraulic cylinders through alternate extension and retraction cycles. A manually operated control valve initiates addition and withdrawal of fluid within the circuit and a logic valve determines which cylinder will be in communication with the control valve. The circuit uses an improved flow restrictor arrangement for creating the pressure drop which automatically shifts the logic valve. The restrictor consists of an orifice, a simple check valve and a constant pressure relief valve, all arranged in parallel. The functions of these various restrictor elements can all be performed by a single multifunction valve disclosed herein.

Abstract: A power steering system for positioning the steerable wheels of a vehicle that provides increased handling feedback to the operator via the steering wheel. The system uses a motor driven pump and a bidirectional hand pump to supply and control fluid pressure for steering the wheels. Two pairs of servomotors steer the vehicle with a first pair receiving a regulating amount of fluid from the bidirectional hand pump and a second pair primarily receiving fluid pressure for moving the steerable wheels from the motor driven pump. In order to increase read ability during selected steering manuevers and change the steering ratio, a compensating valve decreases fluid pressure from the power pump to the second pair of servomotors in response to an operator controlled condition such as turning angle or vehicle speed. The system can also be arranged to have a maximum ratio which will facilitate steering in the absence of fluid pressure from the motor driven pump.

Abstract: A hydraulic motor has its lube drain connected to the motor return line. A motor seal protector valve has a pilot which responds to pressure in the motor return line. Normally, the valve connects system pressure to the motor inlet. High pressure in the return line causes the pilot to move the valve to block the motor feed line and then to connect the motor feed line to sump. In a preferred embodiment, system pressure is connected to the plot to "lock up" the valve in response to return line overpressurization.

Abstract: A weight-balancing system for a farm implement, such as a disk harrow with foldable wings operated by wingfold cylinders, includes a selective control valve for controlling fluid communication to the head and rod ends of the wingfold cylinders. A pair of pressure-reducing/relieving valves permit individual adjustment of the pressures in both the head and rod ends to achieve the desired balance. In a preferred embodiment, a pilot-operated, two-position valve is connected between the rod ends and one of the pressure-responsive valves. The two-position valve is operated by pressure signals generated by a flow-responsive switching valve connected between the two-position valve and the selective control valve. The switching valve and the two-position valve cooperate to block the pressure-controlled outlet of the one pressure-responsive valve and the rod ends and to bypass return fluid flow from the rod ends to sump when the cylinders are being extended.

Abstract: A position-sensing cylinder includes a hollow housing within which reciprocates a piston fixed to a hollow rod. A hollow fitting is threadably attached to one end of the housing. a hollow metallic insert is press fitted into the hollow fitting. An elongated potentiometer support is received by and welded to the insert and is reciprocally received by the hollow rod. The support includes curved edges which slidably engage the wiper wall of the hollow rod and includes a planar support surface upon which are mounted resistive and conductive potentiometer strips. A hollow wiper carrier is mounted for movement with the piston and rod so that the support reciprocates within the carrier and so that conductive wipers are maintained in contact with the potentiometer strips. The wiper carrier cooperates with the rod and the support to substantially prevent fluid flow in the vicinity of the wipers.

Abstract: A fluid supply system includes a pump body having a main bore connectible through inlet check valves to draw fluid from a fluid reservoir and through outlet check valves to supply low pressure fluid to a low pressure function upon reciprocation of a free piston in the main bore. The free piston includes a pair of coaxial driving pistons on either side which extend into main passages which are alternately connected to a high pressure source to cause reciprocation of the free piston. A first spool valve which responds to the completion of a free piston stroke activates a second spool valve which changes the high pressure source connections to the driving pistons.

Abstract: A fluid supply system includes a pump body having a main bore connectible through inlet check valves to draw secondary fluid from a first fluid reservoir and through outlet check valves to supply it to a secondary fluid function upon reciprocation of a free piston in the main bore. The free piston includes a pair of coaxial driving pistons on either side which extend into main passages which are alternately connected to a pressurized primary fluid source to cause reciprocation of the free piston. A first spool valve which responds to the completion of a free piston stroke activates a second spool valve which changes the primary fluid source connections to the driving pistons.