Abstract: A portable drive assembly for driving a chain hoist which includes a drive sheave having a drive shaft extending therefrom that is adapted to be connected to a portable power drill. The drive sheave includes a chain cavity extending around the same for engaging and driving the drive chain associated with a manual chain hoist. To stabilize the portable drive assembly during operation, a stirrup extends from the assembly and the operator is able to stabilize the portable drive assembly by projecting his or her foot into the stirrup. Thus the chain hoist is driven, in either direction, by simply actuating the power drill and holding the portable drive assembly such that the drive sheave continuously engages a lower run of the drive chain.

Abstract: There is disclosed a drill bit which is connectable to the lower end of a rotary drill string for use in drilling oil and gas wells as drilling mud is circulated downward through the string, out the bit, and upwardly within the annulus between the string and well bore so as to remove cuttings therefrom. The bit has cones which are mounted for rotation about thrust bearings which extend inwardly from the lower ends of legs which depend from a shank at the upper end of the bit body which is attached to the drill string.