Hydraulic chuck
AssigneeBoart Longyear Company
InventorGordon Leonard McLaren
Life of this patent
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Abstract
A hydraulic chuck for a drill string has a hydraulic actuator to operate the jaws. The actuator remains stationery while the spindle is rotated and a pair of skirts attached to the actuator cover the bearing assemblies. The jaws are supported in slots in the spindle and are part cylindrical to reduce stress in the spindle. The chuck is secured to a drive unit by bolts received in open slots in an attachment flange to facilitate attachment of the chuck after routine maintenance.
Claims26
A hydraulic chuck for rotating a drill string comprising a tubular spindle, a jaw assembly located on said spindle and including a plurality of jaws radially moveable to engage a drill rod, and a hydraulic actuator operable between said spindle and said jaw assembly to cause radial displacement of said jaws, said spindle including a radial flange having a plurality of recesses extending from the periphery thereof to receive fasteners to secure said spindle to a drive unit and a spigot projecting from said flange to locate said spindle relative to said drive unit.
A chuck according to claimed 8 wherein said jaws are slidably supported in support slots formed on said spindle, said slots having a cross section corresponding to that of said jaws.
A jaw for use in a hydraulic chuck for rotating a drill string, said jaw having a pair of oppositely directed planar faces, said faces being trapezoidal having a pair of spaced parallel edges and wherein a pair of edges extending between said parallel edges are interconnected by an inwardly concave face having a pair of grooves extending parallel to said pair of edges, each of said grooves having an insert located therein to project radially inwardly beyond said face for engagement with said drill string.
Dependencies are inferred from the claim text.