The inventive technology, in certain of its many embodiments, may present a y-number of physically biased, pressurized positioner assemblies, in a single positioner zone, where each assembly includes, inter alia, a plurality of n number of non-precision springs configured in a bimodal or trimodal configuration, and wherein an average of the absolute values of individual deviations, from a design effective spring rate, of the measured, effective spring rates of said positioner assemblies of said zone is less than an average of the absolute values of individual deviations, from said design effective spring rate, of y-number of non-precision springs manufactured to have said design effective spring rate. Spring configurations may be, e.g.: single/double/triple cylinder; single/double pressure cylinder; unimodal/bimodal/trimodal parallel, series and/or nested; internal/external; and/or symmetric/asymmetric. Certain embodiments may include an anti-buckling disc established between series configured springs. Additional aspects of the inventive technology may relate to, e.g., ability to use shorter springs to achieve an intended rate, inter alia.

A compressed gas motor. The motor has a port and a hollow cylinder delimited by a wall with a ventilation opening, a rear closure, and a plunger axially movable in the cylinder. The plunger divides the cylinder into front and back chambers. The ventilation opening is periodically opened towards the back chamber during operation of the motor by movement of the plunger. A compression spring in the front chamber urges the plunger towards the rear closure and/or a tension spring in the back chamber draws the plunger towards the rear closure so that the back chamber is closed relative to the ventilation opening by the plunger and the back chamber is connected with the port when the same pressure prevails in the front and back chambers. The motor can be used in surgical drive systems, medical lavage systems and medical devices. Also disclosed is a method for operating the motor.

The invention relates to a hydraulic circuit (10) for an aircraft turboprop comprising a hydraulic fluid tank (16), a pump (14), a component (12) that is supplied with fluid pressurised by the pump (14) and that is selectively put into operation, and a fluid recirculation circuit (20) between the pump discharge (14) and the tank (16) characterised in that it comprises a valve (22) located in the recirculation circuit (20), that is capable of closing the recirculation circuit (20) when the component (12) is not in operation and is capable of opening the recirculation circuit (20) when the component is in operation.

The invention relates to a hydraulic circuit (10) for an aircraft turboprop comprising a hydraulic fluid tank (16), a pump (14), a component (12) that is supplied with fluid pressurised by the pump (14) and that is selectively put into operation, and a fluid recirculation circuit (20) between the pump discharge (14) and the tank (16) characterised in that it comprises a valve (22) located in the recirculation circuit (20), that is capable of closing the recirculation circuit (20) when the component (12) is not in operation and is capable of opening the recirculation circuit (20) when the component is in operation.

The oscillation cylinder arrangement (100) comprises a working cylinder (10A) and a piston with a rod (27A), arranged to move therein, and a control valve structure (20) for the working cylinder (10A). The control valve structure (20) incorporates a main valve (24) for transmitting a pressure medium to a first sub-chamber or a second sub-chamber of the working cylinder (10A) for a linear movement (A, B) of the piston, as well as impulse valves (22, 23), and lever arms (25, 26) for controlling them, in order to set the operational state of the main valve (24). Control members (27B) fixed to the piston rod (27A) moving in the working cylinder (10A), the control members (27B) being arranged to contact the lever arms (25, 26) of the impulse valves in order to define the extreme positions of the movement of the piston rod (27A).

A system and method for the controlled lowering and lifting of a load are disclosed. The system and method may include operating a work machine having a hydraulic system including a hydraulic actuator for supporting a load, a first control valve in fluid communication with the actuator, and a controller for operating the first control valve. In one embodiment, the controller includes a first algorithm for operating the first control valve in a load lowering operation. When an operational fault within the hydraulic system is detected, the controller can be configured to enter into a safe lowering mode. In the safe lowering mode, the first algorithm is disabled and a pulse width modulation (PWM) current is sent from the controller to the first control valve. A user interface is provided to allow an operator to control the PWM current duty ratio to allow the load supported by the actuator to be lowered.

A system for controllably moving a work implement of a work vehicle having a hydraulic fluid pump for providing fluid to the work implement, the system comprising: at least one operator command tool to produce an operator command signal to move the implement of the work vehicle; at least one sensor to sense a cylinder speed signal indicative of a speed of a hydraulic cylinder coupled to the implement; at least one valve to modulate the fluid flow of the hydraulic cylinder; and a controller.

A system for controllably moving a work implement of a work vehicle having a hydraulic fluid pump for providing fluid to the work implement, the system comprising: at least one operator command tool to produce an operator command signal to move the implement of the work vehicle; at least one sensor to sense a cylinder speed signal indicative of a speed of a hydraulic cylinder coupled to the implement; at least one valve to modulate the fluid flow of the hydraulic cylinder; and a controller.

A system and method for the controlled lowering and lifting of a load are disclosed. The system and method may include operating a work machine having a hydraulic system including a hydraulic actuator for supporting a load, a first control valve in fluid communication with the actuator, and a controller for operating the first control valve. In one embodiment, the controller includes a first algorithm for operating the first control valve in a load lowering operation. When an operational fault within the hydraulic system is detected, the controller can be configured to enter into a safe lowering mode. In the safe lowering mode, the first algorithm is disabled and a pulse width modulation (PWM) current is sent from the controller to the first control valve. A user interface is provided to allow an operator to control the PWM current duty ratio to allow the load supported by the actuator to be lowered.

A system and method for the controlled lowering and lifting of a load are disclosed. The system and method may include operating a work machine having a hydraulic system including a hydraulic actuator for supporting a load, a first control valve in fluid communication with the actuator, and a controller for operating the first control valve. In one embodiment, the controller includes a first algorithm for operating the first control valve in a load lowering operation. When an operational fault within the hydraulic system is detected, the controller can be configured to enter into a safe lowering mode. In the safe lowering mode, the first algorithm is disabled and a pulse width modulation (PWM) current is sent from the controller to the first control valve. A user interface is provided to allow an operator to control the PWM current duty ratio to allow the load supported by the actuator to be lowered.