Abstract: A vehicle having a prime mover, a hydrostatic transmission transmitting power from the prime mover to ground engaging members on said vehicle, a power take-off arranged to be driven by said prime mover and clutch means for selectively engaging the power take-off with the prime mover. The vehicle also includes regulator means operable upon the transmission to maintain the power consumption of the transmission below a predetermined level, and compensating means operable upon the regulator means upon engagement of the clutch means to reduce the predetermined level of power consumption of the transmission.

Abstract: A pump is provided with a regulating device which includes a valve and a motor. The motor operates on the pump to vary the capacity thereof. Movement of the motor is controlled by the valve which has a spool and a body. A feedback link is provided between the motor and the body so that movement of the motor due to a displacement of the spool moves the body to return the valve to neutral. Hunting of the transmission is thus reduced.

Abstract: A transmission having a variable capacity pump and motor is provided with an override device which ensures that the motor is at a maximum capacity, and hence maximum torque capability, prior to operation of other protection devices.

Abstract: A signal is transmitted from a oscillatable piston to a valve by a mechanism comprising a first link pivotal about a second axis and a second link pivotal about a third axis which is perpendicular to the second axis. The second link abuts the first link on both sides of the second axis to transmit motion from the first link to the valve.

Abstract: A hydrostatic transmission is provided with a variable capacity pump and a variable capacity motor. A control is operable to operate sequentially the pump and motor. A second control is provided to operate on the pump to override the signal to the pump from the first control without altering the setting of the motor. The first control thus acts as a ratio selector and the second control as a clutch.

Abstract: A valve which may operate as either a check valve or a relief valve includes a chamber which is connected to a first hydraulic conduit by a restricted passage. A relief valve vents the chamber at a predetermined pressure to unbalance the valve member and allow fluid to flow from the first conduit to a second. The valve member is made with a telescoping portion to allow reverse flow when the first conduit is at a lower pressure than the second.

Abstract: A hydraulic machine is provided with a control for reducing the capacity of the machine when subjected to excessive pressure.A piston is slidable in a cylinder to define two chambers, the chambers being interconnected by a restrictive passage. One chamber is connected to the pressure line and the other chamber is connected to a relief valve so that in the steady state the pressure in each is equal. When the pressure reaches a predetermined level the relief valve opens and vents the other chamber. The passage prevents flow to the other chamber creating a pressure differential which causes the piston to move along the cylinder and operate the machine control to decrease the capacity thereof.

Abstract: In combination with a pump having a variable rate of flow, a device for varying such rate of flow is governed by the pressure generated by the pumps through a variable transmission mechanism the ratio of which depends on the said rate of flow, whereby the power output of the pump can be maintained at a predeterminate value. The device can be used with two pumps for limiting the total power output of both pumps, as being governed by the average of the two pressures.