Linear actuator with rotary positional output

A linear actuator including:

• a cylinder defining a cylinder axis;
• a piston movable within the cylinder along the cylinder axis;
• a piston rod extending axially from the piston for connection to a mechanism whereby in use, movement of the piston actuates the mechanism;
• a rotary output mechanism including 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 being responsive to movement of the piston, and the rotary output element being adapted for operative engagement with an instrument mounted to the cylinder;
• wherein the rotary output mechanism includes a scissor linkage mechanism, including a plurality of elongate linkage elements pivotably interconnected in a criss-cross configuration within the cylinder, with a pivot axis at each end,
• 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, and
• wherein a swivel assembly is interposed between the scissor linkage mechanism and the piston, the swivel assembly enabling relative rotational displacement between the scissor linkage mechanism and the piston around the cylinder axis.