Abstract: An upstanding telescopic cylinder including piston and cylinder sections is provided and the piston and cylinder sections include large, inner and outer relatively telescopingly engaged guide sleeves with the cylinder guide sleeve disposed outermost. The piston section includes small and large diameter guide discs slidably mounted thereon with the small diameter disc lowermost and the piston sleeve includes longitudinally spaced sets of circumferentially spaced notched abutments which successively engage and elevate the large and small diameter discs during extension of the piston section.

Abstract: A first elongated support member is provided and includes second large and small outside cross-sectional area end portions. A cylinder member is provided and includes large and small end portions sealingly and slidingly engaged with the large and small diameter end portions, respectively, of the first support member and defining a peripheral expansion chamber between the support member and the second cylinder member. Structure is provided operative to admit and evacuate fluid under pressure to and from the expansion chamber. A third cylinder member is provided including base and far ends sealingly and slidingly engaged with the large and small end portions of the second cylinder member and with a peripheral expansion zone being defined between the second cylinder member and the third cylinder member between the base and far ends portions of the third cylinder member. Further, structure is provided establishing communication between the expansion chamber and the expansion zone.

Abstract: A hydraulic cylinder comprising a hydraulically operated power lifting ram for lifting heavy loads further includes a guide cylinder concentric about and enclosing the ram, the guide cylinder being secured to the lift platform for further support of the load and reciprocating in unison with the ram under application of hydraulic pressure. The guide cylinder is equipped with a safety locking means which prevents the hydraulic cylinder and its load from lowering in the event of a sudden loss in hydraulic pressure. The safety locking means is in contact with the guide cylinder substantially during the full stroke of the hydraulic operated ram, providing a unique method of locking the cylinder in any position within tolerances normally associated with gear driven devices.