Abstract: A helical screw air compressor unit has a rotary capacity control valve, a compressor inlet throttling valve, and a pressure relief valve for venting the compressor discharge conduit. A control circuit senses pressure in the compressed air supply system downstream of the compressor and operates the capacity control valve, inlet throttling valve, and pressure relief valve in a predetermined sequence to provide an improved power consumption characteristic for variable demand compressor applications. The control circuit includes a hydraulic control valve and an actuator for operating the rotary capacity control valve to regulate compressor throughput to maintain a predetermined pressure without overpressuring the supply system during operation at conditions of reduced demand for compressed air.

Abstract: A drill pipe handling mechanism for a drilling rig includes spaced apart upper and lower arms mounted on a shaft which is mounted for pivotal and limited axial movement with respect to an axis which is spaced from and parallel to the drilling axis. The lower arm includes a receptacle for the lower end of a drill pipe section. The upper arm includes a drill pipe holder having a power actuated movable gate section. A drill pipe retainer is pivotally mounted on the shaft above the pipe holder and is operated by a separate power actuator. Opposed power actuated pipe gripping and holding wrenches are disposed on the lower part of the rig mast for gripping and holding a drill pipe section while threaded joints are broken loose by a rotary head connected to the upper end of the drill string. A power actuated wrench is mounted for pivotal movement into pipe gripping position for breaking loose threaded joints which cannot be loosened by the rotary head.

Abstract: A multispeed gear transmission having an internal gear driving an output shaft. The internal gear is in constant mesh with a plurality of drive pinions. Each drive pinion is connected to a fluid actuated clutch. The driving members of the clutches are driven by respective gears in constant mesh with each other or with a common input gear. Auxiliary output shafts may be driven by a gear meshed with the internal gear or by one of the drive pinions.

Abstract: An automated and adjustable control system for conducting peck drilling operations wherein a drill bit is advanced stepwise in successively increasing penetrations, rapidly retracted after each penetration to remove cuttings, thereafter rapidly advanced toward a work face and then slowed to a drilling advanced rate beginning with the bit a predetermined distance from the work face. Preferably, a pneumatic means rapidly retracts the drill upon completion of each penetration step. A feed rate control unit is partially retracted but limited to a distance less than retraction of the drill. When the drill is rapidly advanced by pneumatic means during each penetration step, the feed rate is decreased by the feed rate control unit to a uniform drilling rate prior to engaging the work face in the work piece.

Abstract: In a two-stage liquid injected helical screw gas compressor a bypass line with a check valve is provided between compressor stages for delivering compressed gas from the first stage directly to the compressed gas receiver and liquid reservoir. Bypass of gas to the reservoir at startup assures pressurization of the reservoir and early flow of liquid to the first and second stage compression chambers. As the working pressure in the second stage discharge line increases above first stage discharge pressure, the check valve closes and all flow from the first stage is conducted through the second stage compression chamber.

Abstract: The drive mechanism of a power ratchet wrench includes a rotary cam which engages a drive ball which in turn is engaged with a push rod for rotating the wrench socket. The push rod is formed with a spherical seat for engaging the drive ball and the cam includes an annular surface which is concavely curved to provide a seat for the drive ball. The drive ball reciprocates in an axial bore in the wrench housing.

Abstract: A rotary cutting tool for forming fluted rotors and the like comprising a cylindrical body having a plurality of metallic carbide cutting blades which are detachably mounted on the circumference of the body. The blades are arranged along a helical line with respect to the axis of rotation of the cutter body. The blades may be circumferentially spaced apart equidistant, one blade from each adjacent blade, to form only one turn of the helix and whereby each blade may be easily ground to a precise cutting edge contour while mounted on the cutter body. The cutting edge contour of each blade may be such that each blade cuts portions along the entire profile of the form produced on the workpiece.

Abstract: A drill cuttings and dust control hood formed as an inverted rectangular box having depending flexible skirts on three lateral sides and a swinging door formed on a fourth side of the box for drill cuttings removal. The dust control hood includes a conical drill cuttings deflector disposed around the drill stem and directly above the drill hole. The conical deflector includes a plurality of apertures disposed around its base and above a transverse baffle plate. A source of air suction is connected to a tangential outlet opening through the deck of the hood into the interior of the space formed within the conical deflector. Flexible collars on the hood deck and the apex of the conical deflector form dust seals around the drill stem.

Abstract: Apparatus for cutting and insulation stripping of twisted conductor wire pairs comprises a wire feed mechanism for feeding predetermined lengths of twisted wire pairs into clamping mechanism including a rotatable clamp operable to untwist a predetermined portion of a wire pair. Movable cams operate to position two wires of the pair whereby dual sets of insulation cutting blades, cooperable with the cams, move in to cut preselected lengths of insulation from the trailing end of a wire pair and the leading end of the next wire pair to be formed. Wire cutting blades operate in unison with the insulation cutting blades to cut the wire pair between the respective sets of insulation cuts. Carriage mechanism is operable to move the wire clamps apart to strip the cut insulation from the respective trailing and leading ends of the wire pairs.

Abstract: A low pressure shutoff valve adapted to be interposed in the fluid supply conduit of a fluid operated torque tool comprises a piston closure member having opposed differential pressure faces exposed to fluid supply pressure and a coil spring for biasing the piston toward a fluid shutoff position. The piston is disposed in a chamber which may be vented by actuating an axially slidable sleeve on the exterior of the valve body whereby the valve is opened to supply pressure fluid to the tool as long as the fluid pressure is greater than a predetermined minimum value.

Abstract: A portable rock drill rig includes a pair of telescoping struts for supporting and positioning a mast or feed beam. The struts are connected at their upper ends to a support bracket which is connected to an elongated mast support member by a hydraulic cylinder to provide relative sliding movement between the bracket and support member. The drill rig includes a crawler undercarriage having spaced apart and pivotally mounted crawler assemblies. The lower ends of the struts are each connected to an arm which is fixed to the main frame of the undercarriage. The arms are also connected to respective track oscillation cylinders. The mounting arrangement of the struts provides for improved positioning of the mast for drilling, tramming and transport operations.

Abstract: A torque tool having a rotation transmitting, torque sensing, energy absorbing, non-overriding mechanism interconnecting a motor and a rotatable driven head. The mechanism includes a driven member coupled to the head and a driver coupled to the motor with the driver yieldably biased toward the driven member. The driven member has cam surfaces facing the driver engaged by bearing surfaces on the driver. The cam surfaces on the driven member permit rotation of the driver relative to the driven member and are sloped such that a preselected torque between the driven member and driver results in the rotation and translation of the driver relative to the driven member. The translation is communicated for the release of a valve rod which actuates a valve to shutoff the motor. The kinetic energy causing relative rotation after shutoff of the motor is stored and dissipated by springs.

Abstract: Mechanism for providing and controlling long stroke turret slide movement in an automatically operable screw machine. Means are provided to obtain a longer stroke of the turret slide than is normally possible in an automatically operable screw machine. Fluid operable means control the movement of the turret slide member or turret support member with respect to a mechanically operable carrier member upon which the turret slide member rests.

Abstract: A drill pipe bushing for stabilizing the drill pipe at the mouth of the well during drilling includes a plurality of support arms supported in a circular array about the drill pipe. Rollers are attached to each support arm with the axis of the rollers normally parallel to the axis of the drill pipe. The support arms move the rollers into engagement with or away from the drill pipe. The rotational axis of the rollers become canted upon both rotation and translation of the drill pipe through the drill pipe bushing during the drilling operation.

Abstract: A power transmission mechanism includes a hydrokinetic torque converter and a friction clutch disposed to form a positive mechanical drive from the input shaft to the output shaft of the torque converter. The friction clutch includes a piston disposed in the housing and forming opposed fluid chambers one of which includes the converter impeller and turbine disposed therein. An orifice in the piston conducts fluid from one chamber to the other and clutch engagement is controlled by regulating the fluid outflow from the other chamber. Clutch lockup or engagement may be controlled to be responsive to the pressure of fluid flowing into the converter or the difference in the pressure of the fluid flowing in and out of the converter.

Abstract: A tensioning mechanism for the fluid conductor hoses of a feed mounted rock drill comprises a plurality of fluid cylinders mounted stationary on a bracket supported midway along the length of the drill feed channel. Elongated tubular pistons are slidably supported in the cylinders and are connected to the respective hoses. The cylinders may be charged with pressure fluid such as grease or the like to bias the pistons to tension the hoses and prevent damage to the hoses or interference with movement of the drill.

Abstract: A positive displacement gas compressor includes an inlet throttling valve which has an actuator responsive to a pressure fluid signal for closing the throttling valve. A control circuit for supplying pressure fluid to close the throttling valve includes a time delay device and a pilot operated valve which vents the pressure fluid signal holding the throttling valve closed after a predetermined time period commencing with startup of the compressor.

Abstract: A plurality of mounts carry a weighbridge or platform. Each mount has a transducer that carries the mounts portion of the load and indicates weight by strain in shear. The weighbridge loads a horizontal cross pin. The pin, in turn, loads a link that loads a second, integrally connected link. The second link loads the middle of the transducer of the mount in shear. The transducer and cross pin lie orthogonally. The ground rigidly supports the ends of the transducer. The links coupling the transducer and cross pin transmit only vertical forces to the transducer to load the latter only in shear and permit horizontal movement of the weighbridge.

Abstract: A hydraulic percussion tool for developing repeated impact blows for rock drilling and other high force applications is characterized by a piston hammer reciprocably disposed in a cylinder bore and a tubular valve member coaxial with and actuated by the hammer for controlling the flow of pressurized hydraulic fluid to and from portions of the cylinder bore. The valve member is actuated by the hammer on the return stroke thereof through a column of fluid trapped in an annular chamber formed between a transverse surface on the hammer and an end face of the valve member. Valving mechanism is operable to effect controlled venting of the trapped fluid from the annular chamber to change the position of the valve member with respect to the hammer and thereby control the hammer stroke length, impact blow, and blow frequency.