Abstract: Hydraulic cylinders include a number of features that are useful in a number of industries. The great advantage telescopic cylinders have over any other type of cylinders is their ability to provide an exceptionally long stroke from a compact initial package. Controlling the extension and retraction of the stages of a telescoping cylinder mitigates mis-staging, which is an unwanted result of some telescoping cylinders. Spherical bearings at the end mount of cylinders, either telescoping or not, can be cleaned using scrapers, which will extend the life of the bearings in the field. The rods of cylinders, either telescoping or not, can also be cleaned with additional scrapers at key locations to further remove unwanted and potentially damaging material that can build up on the rods, such as due to the environment of use for the cylinders.

Abstract: This invention is a bi-directional hydraulic actuator comprising a piston assembly positioned within a housing. The piston assembly is configured to move linearly within the housing. A gland is operatively connected to the piston assembly. The gland is configured as a rigid longitudinally annular member with a first end, a second end, a sidewall and is open on the first end and substantially closed on the second end which forms an inside and an outside of the annular member. The gland is further configured with a lip extending from around the outside of the first end of the gland. A pressurizing fluid exerts pressure on the inside of the gland to move the piston assembly a first direction, then, a fluid exerts pressure on the outside of the gland and the lip of the gland to move the piston assembly opposite the first direction.