A resister clip (35) includes engage portions (35a) engaging with an engage groove, a spring portion (35b) and operating portions (35c). The spring portion (35b) can be designed with a high degree of freedom in terms of a coil number of turns, a winding diameter and others and the engage portions (35a) are widened centering on the spring portion (35b), so that diameter-widening resistance can be optimized.

A hydraulic tensioning device for a chain drive, having a tensioning piston which is guided in a holder and which, on its outer circumferential surface, has locking grooves, an inner guide which projects into a cavity of the piston, and a locking element which has at least two annular sections and at least two radial extensions, wherein the locking element can be placed in engagement by the at least two annular sections with one of the locking grooves, and having a clamping stop and a sliding stop which are axially spaced apart from one another. To simplify the structural design, the holder has at least two axial extensions which extend in an axial direction between the clamping stop plane and the sliding stop plane, wherein the at least two axial extensions and the tensioning piston do not enclose the at least two radial extensions.

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.

A line strainer for use in an electric fence system is described. The line strainer includes a unitary body made of electrically non-conductive material, having two opposing arms, a spool mounting element for rotatably mounting an electrically conductive spool having at least one toothed flange between the arms of the body, wherein the spool is configured to have a first line secured to it. The line strainer further includes a line bearing support member about which a second line is to be passed and tensioned. A releasable pawl is attached to the unitary body and configured to engage with the at least one toothed flange to restrict rotation of the spool in one direction when the spool is rotatably mounted to the spool mounting element.

A piston assembly for a tensioner which has a hollow piston body having a first end and a second end; and a cap. At least a portion of the cap fits into the first end of the piston body. The cap has a head and may also have a stem connected to an underside of the head. The cap may also have at least one slit for venting fluid, having 5 a width and a depth. The slit may extend from an outer circumference of the stem and across the underside of the head. The slits may be parallel to a centerline of the cap or angled relative to the centerline of the cap. A plurality of slits may be present on the cap. At least two of the plurality of slits may have different widths or different depths. The slits may be evenly 10 spaced around the cap.

A chain tensioner includes a housing that forms a cylindrical receptacle. A piston is surrounded at least in part by the receptacle. The inner surface of the receptacle axially guides the piston when the piston travels into and out of the housing. The chain tensioner further includes a locking unit which limits the inward travel of the piston. The locking unit includes a stop facing the housing, and a mating stop facing the piston. A locking element establishes a force-transmitting connection between the stop and the mating stop. At a location of the stop facing the housing, the housing axially forms a locking section that is located between the locking element and the piston. The locking section includes at least one recess, allowing the locking element to establish the force-transmitting connection between the stop and the mating stop.

A chain tensioner includes an oil supply passage for supplying hydraulic oil into a pressure chamber defined by a cylinder and a plunger, and a check valve provided at the end of the oil supply passage. A leak gap is defined between the sliding surfaces of the cylinder and the plunger. The plunger is biased by a return spring in the direction in which the plunger protrudes out of the cylinder. A plug is press-fitted in a cylindrical inner periphery of a through hole formed in the plunger to extend from a protruding end surface of the plunger to the pressure chamber to define an air vent passage. It is possible to change the hydraulic damper force simply by replacing the plug with another different kind of plug to define a different air vent passage.

To provide a simple-structured chain tensioner that reduces the burden of work required for assembling and maintenance, sufficiently damps the motion of the plunger, and helps reduce machining costs and size increases of the plunger and tensioner body. The chain tensioner includes a tensioner body with a plunger bore, a plunger, and a biasing member that biases the plunger. The plunger has raised portions with which a locking member engages. The plunger bore is provided with a locking member holding part on one side that is open. The locking member holding part is provided with an inclined surface at one end in the plunger entry direction, the inclined surface becoming progressively shallower in the plunger entry direction. The locking member can deform elastically in a cross section when engaging with the raised portion of the plunger.