The subject matter of this specification can be embodied in, among other things, a locking apparatus for a rotary actuator includes an outer housing comprising a cylindrical interior surface having a recess. A rotor is disposed within the outer housing. The rotor has an interior cavity and a port extending radially from the interior cavity to the cylindrical exterior surface. A piston is disposed for reciprocal movement within the interior cavity between a first position and a second position and includes a first portion having a first thickness, a second portion having a second thickness larger than the first thickness. A key is disposed for radially reciprocal movement within the port and includes a radially proximal end and a radially distal end. The radially proximal end contacts the first portion and the radially distal end does not extend into the recess when the piston is in the first position.

A hydraulic tensioning device for a chain drive, including tensioning piston, which is guided in a holder and which has locking grooves on the outer peripheral surface of the tensioning piston, and including a locking element, which has at least two annular sections and at least two radial extensions, wherein the locking element can be brought into engagement with one of the locking grooves by the at least two annular sections, and including a clamping stop and a sliding stop, which are axially spaced apart from each other. In order to simplify the design, the holder has at least two axial extensions, which extend in the axial direction between the clamping stop plane and the sliding stop plane. The at least two axial extensions and the tensioning piston do not enclose the at least two radial extensions.

Aspects of the disclosure are directed to a safety adapter that is removably and replaceably securable to a hollow lock nut hydraulic cylinder that includes a threaded collar. The safety adapter may comprise a cylindrical sidewall having a distal axial end and proximate axial end, that at the distal axial end includes a top surface having a center through hole and at the proximate axial end includes a sidewall threaded surface on an interior surface of the cylindrical sidewall configured and arranged to engage with the threaded collar.

A hydraulic jack for providing safety and security is disclosed. The hydraulic jack comprises a hydraulic cylinder storing hydraulic fluid inside, and a piston installed in the hydraulic cylinder that is raised up from the hydraulic cylinder by pressure of the hydraulic fluid stored in the hydraulic cylinder, thereby a heavyweight can be lifted by the piston. The piston has at least one drill hole on its body thereof that has a determined diameter and is perpendicular to the piston. A security piece is attachable on a top portion of the hydraulic cylinder. The security piece comprises a pair of through holes, which align with at least one drill hole of the piston.

The subject matter of this specification can be embodied in, among other things, a locking apparatus for a rotary actuator includes an outer housing comprising a cylindrical interior surface having a recess. A rotor is disposed within the outer housing. The rotor has an interior cavity and a port extending radially from the interior cavity to the cylindrical exterior surface. A piston is disposed for reciprocal movement within the interior cavity between a first position and a second position and includes a first portion having a first thickness, a second portion having a second thickness larger than the first thickness. A key is disposed for radially reciprocal movement within the port and includes a radially proximal end and a radially distal end. The radially proximal end contacts the first portion and the radially distal end does not extend into the recess when the piston is in the first position.

A cylinder prop assembly is cooperable with a lift cylinder for a scissor lift and includes a cylinder prop displaceable between a disengaged position, in which the cylinder rod is movable relative to the cylinder housing, and an engaged position in which the cylinder rod is locked from displacement relative to the cylinder housing. An actuation lever is coupled with the cylinder prop and is accessible to displace the cylinder prop between the disengaged position and the engaged position.

The subject matter of this specification can be embodied in, among other things, a locking apparatus for a rotary actuator includes an outer housing comprising a cylindrical interior surface having a recess. A rotor is disposed within the outer housing. The rotor has an interior cavity and a port extending radially from the interior cavity to the cylindrical exterior surface. A piston is disposed for reciprocal movement within the interior cavity between a first position and a second position and includes a first portion having a first thickness, a second portion having a second thickness larger than the first thickness. A key is disposed for radially reciprocal movement within the port and includes a radially proximal end and a radially distal end. The radially proximal end contacts the first portion and the radially distal end does not extend into the recess when the piston is in the first position.

A safety device for maintaining a load raised cylinder linkage in selected extended position. A combination cylinder engagement rod and locking sleeve with a piston rod engagement channel that will adjustably secure and extended piston rod from a cylinder assembly in a safe secure locked extended position. The cylinder safety stop of the invention is interposed between the cylinder sleeve and the piston end block by the incrementally adjustable engagement panel's positioning via removably positioned stop adjustment pin. An intermediate incrementally adjustable fitting provides for positioning between multiple aligned stop pin engagement apertures.

The disclosure relates to exemplary embodiments for a combination device configured to effect lockout and partial stroke testing for an actuator having a piston rod providing linear motion and connected to a guide block in an actuator, wherein the combination device includes a device housing having a housing bore, wherein the device housing is adapted to mount on a receptacle on the actuator that aligns a device housing bore coaxially to the translatory motion axis of the piston rod; an extension rod attached to the guide block connected to the piston rod; at least two slides or a profiled bore index sleeve disposed in the device housing that when engaged provide means of restraining the movement of the extension rod in a manner that prevents said extension rod and a driver element of the actuator from rotating, relative to an actuator housing; a housing cover mounted over the device housing wherein the housing cover protects and retains the extension rod, and the slides or the index sleeve in the device housing and a spring biased safety pin mounted on the housing cover wherein the spring biased safety pin is configured to prevent unintended actuation of the actuator; and a tubular cover to protect the extension rod.

The present disclosure relates to a device for locking an actuator, preferably a locking sleeve, having two half-shells that are pivotable relative to one another between an open position and a locking position, which are configured in such a way that, in the locking position, the two half-shells are in abutment with each other at their end faces facing each other. The device does not have a bayonet lock, but a web-and-groove connection.