The present invention makes a rotary movement smooth, the rotary movement allowing direct detection of the movement of an output member of a rotary clamp. In a clamp, an output member is accommodated in a cylinder hole. A first valve chamber, to which compressed air is supplied, is provided between a lower wall of a housing and the output member. A second valve chamber is a hollowed out portion of the output member so as to be provided open toward the first valve chamber. A valve rod is inserted into the second valve chamber from the lower wall. A valve rod passage that allows the second valve chamber to communicate with outside air is provided in the valve rod, and a seal section is provided in a peripheral gap where the valve rod and the second valve chamber move relatively to one another. The gap is formed so that, as the valve rod and the second valve chamber are in relative movement, there is a region which is sealed by the seal section against movement of the compressed air through the gap between the valve rod and the second seal chamber and the there is a region which is open from the seal.

A linear displacement sensor for telescoping cylinders, actuators, shock absorbers and dampers is disclosed. Said sensor being generally comprised of two parts-a contact and a resistor strip. The aforementioned invention having several embodiments: one embodiment having a contact disposed on the piston rod inside the cylinder and a resistor strip configured along the internal cylinder wall; another embodiment having a contact disposed at an outside end of the cylinder and the strip imbedded inside a groove along the piston rod. All embodiments including a plurality of insulated rod and wall groove shapes for said resistor strip. An object of the invention is to provide a means for measuring actuator displacement both inside and outside of an actuator.

A cylinder stroke determination system and a method of determining a stroke of a cylinder are provided. The system includes a cylinder having a rod and a barrel, a sensing cylinder configured to operate with the cylinder, and a processor. The sensing cylinder includes a sensing cylinder base coupled to the barrel of the cylinder, a sensing cylinder rod coupled to the connecting portion of the rod of the cylinder, a photon emitter coupled to the sensing cylinder base and configured to emit a photon toward a photon target disposed at the sensing cylinder rod, and a photon receiver coupled to the sensing cylinder base and configured to receive the photon reflected from the photon target. The processor is configured to determine a stroke of the cylinder based on a time of flight of the photon from the photon emitter to the photon receiver.

A cylinder stroke determination system and a method of determining a stroke of a cylinder are provided. The system includes a cylinder having a rod and a barrel, a sensing cylinder configured to operate with the cylinder, and a processor. The sensing cylinder includes a sensing cylinder base coupled to the barrel of the cylinder, a sensing cylinder rod coupled to the connecting portion of the rod of the cylinder, a photon emitter coupled to the sensing cylinder base and configured to emit a photon toward a photon target disposed at the sensing cylinder rod, and a photon receiver coupled to the sensing cylinder base and configured to receive the photon reflected from the photon target. The processor is configured to determine a stroke of the cylinder based on a time of flight of the photon from the photon emitter to the photon receiver.

The present invention includes a stroke sensor which is arranged on a hydraulic cylinder and measures a stroke length of the hydraulic cylinder; a rotary encoder and a magnetic force sensor which measure a reset reference point to reset a value of the stroke length measured by the stroke sensor; a stroke end detection processing unit which detects a stroke end position of the hydraulic cylinder; a calibration processing unit which calibrates the measured value of the stroke length when the reset reference point and/or the stroke end position is detected; an HMI monitor which displays an entire work machine mounted with the hydraulic cylinder when an initial calibration work for the hydraulic cylinder is carried out; and a highlight display processing unit that highlights a moving portion to drive a hydraulic cylinder to be calibrated along with an indication of a driving direction.

A cylinder with position feedback sensor, including a barrel (11), a piston rod (12) and piston (15). Markings (M) associated with a central portion of the piston rod (12C) are readable by a sensor (S). In practice, the freedom of slidable movement of the piston rod (12) is such that the markings are retained at all times entirely within the barrel (11) during use so that the external environment cannot influence (e.g. damage) the markings.

In a fluid pressure cylinder having a body having a pair of cylinder holes, a pair of pistons movably accommodated respectively in the pair of cylinder holes, a pair of piston rods secured respectively to the pair of pistons, and an end plate connected to end portions of the pair of piston rods, each of the pistons partitions the corresponding cylinder hole into a head-side cylinder chamber and a rod-side cylinder chamber. The body includes a solenoid valve configured to switch between supply of pressurized fluid to the head-side cylinder chambers or the rod-side cylinder chambers and discharge of the pressurized fluid from the head-side cylinder chambers or the rod-side cylinder chambers, and the solenoid valve is disposed inside a surface of the body.

A method and an apparatus (280) for determining an estimate of a position of a hydraulic subsea actuator (200), wherein the hydraulic subsea actuator (200) has a fluid port (220) fluidly connected to a fluid source (260). The apparatus (280) comprises a hydraulic cylinder (310) connected in series between the fluid source (260) and the fluid port (220) of the hydraulic subsea actuator, and a movable piston (320) arranged in the second hydraulic cylinder (310), a position determining device, arranged to determine a position of the movable piston (320), and a signal processing device (350), arranged to calculate the estimate of the position of the hydraulic subsea actuator based on the position of the movable piston.

The present disclosure relates to a piston-cylinder unit with a cylinder jacket and a piston rod longitudinally shiftably guided in the cylinder jacket as well as an evaluation unit which determines the position of the piston rod with respect to the cylinder jacket by the intrinsic electrical properties of an interconnection of cylinder jacket, piston rod and piston, wherein the piston rod is short-circuited against the cylinder or the cylinder head in a manner suitable for high frequencies via one or more contact elements in the region of the exit opening of the piston rod out of the cylinder head.

A gas cylinder actuator with overtravel indicator device, which comprises: a tubular containment jacket, an end face, an opposite annular guiding portion for a stem-piston, which protrudes from the jacket in an axial direction, a stem-piston arranged so as to pass through the annular portion, a chamber for pressurized gas being defined between the tubular jacket, the end face, the annular passage portion for a stem-piston and the stem-piston, a device for indicating that overtravel for the stem-piston has occurred; and an annular body, which is inserted partially into a corresponding seat between the jacket and the annular portion so as to surround the outer lateral surface of an end portion of the annular portion; the annular body rests in an axial direction on an element that protrudes radially within the jacket and is integral with the jacket.