Abstract: Drill string components having at least two threads extending around a body. The leading end of each thread can have a configuration having increased strength and resistance to jamming and cross-threading. In particular, the leading end of each thread can comprise a planar surface normal to the body. The leading end of each thread can provide an abrupt transition to full thread depth that helps reduce or eliminate cross-threading and can be oriented at an angle relative to the axis of the drill string component. Each thread can further provide at least one of a variable thread width and a variable thread pitch configured to create an axial progressive fit. Each thread can also provide a cylindrical thread root and a thread crest that circumscribes a frusta-cone over at least a portion of the axial length of the threads configured to create a radial progressive fit.

Abstract: A closed loop control system for a core drilling mechanism automatically controls the penetration rate, the weight on the drill bit, and the torque load applied to the drill string, and maintains all three at or below preselected maximum values. The closed loop control system incorporates a controller that receives sensed information and generates corresponding control signals to control the penetration rate and thus the weight on the drill bit and the torque load through a servo valve in a hydraulic drive circuit. One or more sensors are provided to sense the penetration rate of the drill bit, and are coupled with the controller. Similarly, sensors are provided to determine the weight on the drill bit and the torque load applied to the drill string.

Abstract: An improved drilling rig having a drillhead assembly positioned onto a mast for vertical movement therewith. The drillhead assembly is hung by cables threaded from a hoist assembly positioned at the top end of the mast. One or more cable return assemblies are positioned at the bottom end of the mast. The cables are counter-wound on the hoist assembly such that the cables roll off of the hoist assembly in the direction towards the drillhead assembly at the same rate the cables are pulled onto the hoist assembly from the direction towards the cable return assemblies. The drillhead assembly has a drive motor assembly rotatably mounted within a frame. A break-out tool assembly is mounted at the lower end of the mast. The break-out tool assembly has means for grasping rotating a length of string so as to separate the lengths of string.

Abstract: A moisture testing device having various applications including the testing of moisture in the thermal insulation of insulated pipe, the device having a readout and related components connected to a detector assembly which is pivotally mounted at the end of an adjustable pole. The detector assembly utilizes the principle of neutron back scatter or neutron moderation which is known for measuring water and hydrogen, but it is designed as a highly efficient screening device which can for example test thousands of feet of pipe in a day.

Abstract: A wall saw for cutting concrete or similar materials includes a track, mounting brackets to affix the track to a wall, and a movable saw carriage. The saw carriage is mounted to the track by a guide mechanism, which may include a plurality of rollers, mounted to the carriage for pivotal movement between an engaged position, in guiding contact with the track, and a retracted position, out of contact with the track, by movement of a carrying handle of the carriage. In one embodiment, the rollers are mounted for pivotal camming motion and are retracted sufficiently in their retracted positions to permit mounting and dismounting of the carriage relative to the track by movement of the carriage perpendicular to the wall.