Abstract: A backhoe has a main boom mounting a jib boom rotatably and pivotally. The jib boom journals a yoke about one axis and a bucket is pivotal on the yoke about a transverse axis and a hydraulic cylinder drive having a double-ended piston extending between arms of the yoke is adjustable to tilt the bucket to keep its lower edge level when desired.

Abstract: An hydraulic nut including an annulus, typically of stainless steel, having an annular cavity therein. The cavity is sealed pressure-tight by an annular deformable membrane of the same material as the annulus which is welded to the annulus about the cavity by a fusion weld. An hydraulic fluid, under pressure, typically grease, is injected into the cavity. The membrane is backed up by an annular shoe and the force produced by the pressure is transmitted through the membrane and the shoe to the object to which the force is applied. Very high forces may be applied by this apparatus.

Abstract: An expansion joint lock for transmitting forces between structural members that contract as they are cooled down to operating temperatures. A piston member mounted to one structural member is slidingly engaged with a chamber in a reception member which is mounted to a second structural member. The remaining space in the chamber is filled with a liquid which freezes at a temperature somewhat above the operating temperature of the structure, allowing forces to be transmitted between the structural members by the frozen liquid.

Abstract: A pre-tensioned, screwed joint is assembled or disassembled by using a piston and rod arrangement to elastically extend the screw while a nut is applied or removed.

Abstract: A hydraulically operable device for stretching a hollow roll arbor to slightly reduce the arbor diameter in order to fit rolling sleeves around the arbor. The device includes a rod which is inserted into the hollow arbor and a hydraulically operable piston and cylinder arrangement at one end of the rod to apply a load through the rod to the arbor. A circular split collett extends around the piston and cylinder arrangement and engages at one end in a reaction block which reacts in response to the applied hydraulic pressure and at its other end with the roll arbor. The collett is held to the reaction block and to the arbor by annular rings, so that when a load is applied to the rod, the arbor is stretched longitudinally.

Abstract: Damage due to rupture or ballooning of the plastic jacket on a flexible pumping strand due to filling of the well with gas is prevented by providing an assembly including a preset pressure release valve in the lower portions of the strand to quickly release fluid from the interior of the strand to the surrounding environment upon the attainment of a pressure differential between the interior and exterior of the strand within a predetermined fraction of the rupture or ballooning strength of the plastic jacket on the pumping strand.