This invention provides a linear actuator with a cylinder defining a cylinder axis. A piston is movable within the cylinder along the cylinder axis, and a piston rod extends axially from the piston for connection to a mechanism whereby in use, movement of the piston actuates the mechanism. A rotary output mechanism includes a rotary output element extending generally transversely from the cylinder and supported for rotation about an output axis generally normal to the cylinder axis. The rotary output mechanism is responsive to movement of the piston, and the rotary output element is adapted for operative engagement with an instrument mounted to the cylinder such that axial movement of the piston effects a corresponding rotational displacement of the rotary output element, whereby in use the instrument provides an output signal indicative of the position of the piston within the cylinder.

A sensor unit for a fluidic cylinder having a base carrier on which a circumferential seal is formed, so that an interior of the fluidic cylinder is sealable, and having a position sensor for detecting a position of the piston, and having a pressure sensor for detecting a pressure in the interior.

A position sensor (1.1, 1.2) for a working cylinder (2.1, 2.2) with a cable drum (4.1, 4.2), a cable (5) with a piston anchor (7.1, 7.2) and an interface (13.1, 13.2) for determining a position and a movement of a piston (3.1, 3.2) of the working cylinder (2.1, 2.2), the position sensor (1.1, 1.2) is to be operatively connected to the working cylinder (2.1, 2.2) from outside in the area of a cylinder head (15.1, 15.2).

The embodiments disclosed herein relate to a position sensing system for an actuator of a valve, including a piston of the actuator, wherein the piston is configured to actuate the valve between an open position and a closed position; a sensor including a drum; and a wire wound around the drum at a first end of the wire; wherein the sensor is configured to detect a rotation of the drum; and wherein a second end of the wire is connected to the piston.

A sensor unit for a fluidic cylinder having a base carrier on which a circumferential seal is formed, so that an interior of the fluidic cylinder is sealable, and having a position sensor for detecting a position of the piston, and having a pressure sensor for detecting a pressure in the interior.

A position sensor (1.1, 1.2) for a working cylinder (2.1, 2.2) with a cable drum (4.1, 4.2), a cable (5) with a piston anchor (7.1, 7.2) and an interface (13.1, 13.2) for determining a position and a movement of a piston (3.1, 3.2) of the working cylinder (2.1, 2.2), the position sensor (1.1, 1.2) is to be operatively connected to the working cylinder (2.1, 2.2) from outside in the area of a cylinder head (15.1, 15.2).

A hydraulic actuator with a sensor mounted on the actuator cylinder for determining the position of the actuator. The arrangement comprises a hydraulic actuator which includes a cylinder having a bore in which a piston is slidably mounted for movement along the cylinder to extend and retract the hydraulic actuator. The cylinder has a side wall and a cylinder aperture extending through the side wall. A wire actuated encoder is mounted on the external surface of the cylinder, which has a wire which extends through the cylinder aperture and is attached to the piston for determining a stroke position of the piston within the cylinder.

In order to arrange a sensor unit completely in an interior e.g. of a cylinder of a piston cylinder unit and in order to be able to use a tension element sensor as a sensor the sensor unit is configured so that it includes a pressure tight wall through which a magnetic field sensitive sensor is configured to detect a magnetic field of an encoder magnet that moves on another side of the pressure tight wall and represents a rotational position and rotations of the winding drum whereas a housing of the sensor unit is sealed relative to an interior of the cylinder so that the sensor cavity in which the sensor is arranged represents a low pressure cavity which is advantageously only subjected to ambient pressure. This avoids hollow boring of the piston rod and no magnetic field permeable window has to be fabricated in a wall or in a base of the cylinder.

This invention provides a linear actuator with a cylinder defining a cylinder axis. A piston is movable within the cylinder along the cylinder axis, and a piston rod extends axially from the piston for connection to a mechanism whereby in use, movement of the piston actuates the mechanism. A rotary output mechanism includes a rotary output element extending generally transversely from the cylinder and supported for rotation about an output axis generally normal to the cylinder axis. The rotary output mechanism is responsive to movement of the piston, and the rotary output element is adapted for operative engagement with an instrument mounted to the cylinder such that axial movement of the piston effects a corresponding rotational displacement of the rotary output element, whereby in use the instrument provides an output signal indicative of the position of the piston within the cylinder.

In order to arrange a sensor unit completely in an interior e.g. of a cylinder of a piston cylinder unit and in order to be able to use a tension element sensor as a sensor the sensor unit is configured so that it includes a pressure tight wall through which a magnetic field sensitive sensor is configured to detect a magnetic field of an encoder magnet that moves on another side of the pressure tight wall and represents a rotational position and rotations of the winding drum whereas a housing of the sensor unit is sealed relative to an interior of the cylinder so that the sensor cavity in which the sensor is arranged represents a low pressure cavity which is advantageously only subjected to ambient pressure. This avoids hollow boring of the piston rod and no magnetic field permeable window has to be fabricated in a wall or in a base of the cylinder.