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A hydraulically operated slip assembly, connectible to a well head or well pipe handling machine and useful to intermittently grip pipe being run into or pulled from the well. The slip assembly has upper and lower plates with passages for pipe. Wedges, carrying unique slip systems, are positioned ar

A hydraulically operated slip assembly, connectible to a well head or well pipe handling machine and useful to intermittently grip pipe being run into or pulled from the well. The slip assembly has upper and lower plates with passages for pipe. Wedges, carrying unique slip systems, are positioned around the passages and slidably mounted for radial movement between guide plates extending from the upper and lower plates. The wedges are moved radially inward to grip pipe and radially outward to release pipe by a hydraulic cylinder, pivotally mounted aside the lower plate. When actuated to extend, the hydraulic cylinder rotates an inner bearing race and attached camming segments, which move the wedges inwardly to grip pipe. When the cylinder is actuated to contract, the bearing race and camming segments are rotated to pull the wedges outward radially, releasing pipe. The bearing outer race is housed in ring segments between and connecting the slip assembly upper and lower plates. The unique slip systems automatically increase pipe grip, on up or down movement of gripped pipe caused by very small loads. Outward force components, resulting from increased pipe grip, press the outer surfaces of the camming segments into ring segment grooves, developing forces which effectively prevent inadvertent or an purpose actuation of the cylinder from rotating the camming segments to ungrip pipe in the slip assembly.

대표청구항 ▼

An improved hydraulically actuated double acting slip assembly comprising: (a) housing means including a lower plate with a connector thereon and a passage for pipe therethrough, an upper plate with a passage for pipe therethough, and ring segments, each having a horizontal groove therein, positione

An improved hydraulically actuated double acting slip assembly comprising: (a) housing means including a lower plate with a connector thereon and a passage for pipe therethrough, an upper plate with a passage for pipe therethough, and ring segments, each having a horizontal groove therein, positioned between said plates and around said pipe passages and connected to said plates; (b) radial guiding means disposed in said housing means around said pipe passages; (c) gripping means, slidably mounted in said guiding means for gripping pipe passing through said plate passages, including double acting slip means for gripping gripped pipe tighter, automatically actuated by thrust on gripped pipe sufficient to cause vertical movement of the gripped pipe including, wedges mounted in said guiding means, each wedge having a female ‘T’slot across its outer surface and upper and lower downwardly and inwardly inclined surfaces on its inner face and a recess in the upper inclined surface, said recess having a lower planar surface, secondary wedges, mounted on said wedges, each having upper and lower downwardly and inwardly inclined surfaces on its outer face, engaging said wedge inclined surfaces, means slidably connecting said secondary wedges to said wedge for downward movement, each secondary wedge also having upper and lower downwardly and outwardly inclined surfaces on its inner face and a hole between said secondary wedge upper inclined surfaces on its inner and outer faces, said hole having a lower planar surface, slip means, mounted on said seconary wedges, including a slip having upper and lower downwardly and outwardly inclined surfaces on its outer face and a recess in said slip upper inclined surface, said recess having a lower planar surface and said slip inclined surfaces engaging said secondary wedge inner face inclined surfaces, means for slidably connecting said slip means to said secondary wedges for upward movement, a bar having a first hole therethrough, pivotally mounted in each wedge recess, and extending through the secondary wedge hole and into the slip recess, and biasing means, disposed in each secondary wedge, biasing said bar downwardly and aligning the lower planar surfaces of the wedge recess, the secondary wedge hole and slip recess, to position the secondary wedge and slip means in position for pipe grip tightening actuation; (d) single cylinder actuating means for moving said gripping means inwardly and outwardly in said guiding means to grip and ungrip pipe; and (e) means preventing said actuating means from being actuated to release gripped pipe when thrust on gripped pipe has actuated said slip means.