Abstract: A combination scratcher-centralizer for use in installing casing in wellbores comprising a single piece of coiled wire or rod having a first hub part for tightly engaging the casing, a radially expanded centralizer and scratcher portion forming a helical wrap of said wire and a second hub part slidable on the casing and formed by a helical wrap of said wire. The first hub part includes serrations and/or a plurality of retaining screws provided so that the first hub part may be secured to the casing in a predetermined position to allow the expanded centralizer coil or wrap portion to undergo some elastic axial excursion during its scratching and scraping operation upon installation in a wellbore. The constricted hub part may be held in a radially expanded position during installation by a retainer engageable with spaced apart portions of the wraps of the hub part.

Abstract: A bridge structure is provided for short bridges spans of eighty feet or less in length and includes a series of girders consisting of flanged steel beams. The girders are maintained in place by lateral braces which hold the girders with a series of tie rods or bolts affixed thereto. In one embodiment the lateral braces are formed with top and bottom steel members of relatively small size and which are notched to help maintain the girders in position. Side rail posts are affixed at the ends of the lateral braces for attachment of a guardrail or the like. The longitudinally positioned girders are not welded or weakened with bolt holes therethrough and the structure provides a convenient and economical bridge constructions for use with conventional timber or other decking.

Abstract: A delivery system for an agriculturally active chemical comprises a body or carrier portion including a first water dispersible agriculturally inert and essentially nontoxic composition containing a predetermined aliquot of the agriculturally active chemical. The body or carrier portion has a predetermined size and a predetermined shape. The delivery system also comprises a protective coating, about the body portion, of a second water dispersible agriculturally inert and essentially nontoxic composition. The aliquot of the agriculturally active chemical is an amount of the agriculturally active chemical effective to terminate functioning of a target agricultural pest upon application of the agriculturally active chemical to soil or water via the delivery system. The agriculturally active chemical can take the form of a biocide such as an insecticide, fungicide or nemacide.

Abstract: A variable speed mechanism comprises a constant speed transmission set, a variable speed transmission set, a sun gear set comprising a first sun gear and a second sun gear, a locating member, two planetary gear sets, and a power source. The first sun gear is actuated to rotate at a constant speed by the constant speed transmission set. The rotating speed of the second sun gear 32 can be altered by adjusting the variable speed transmission set so as to cause the rotation of a power output shaft of the speed changing mechanism to accelerate, decelerate, reduce to zero, or reverse.

Abstract: Transmission unit for motor vehicles, consisting of a continuously variable transmission (2); at least one hydraulic cylinder/piston unit (13) with a pressure cheer (15) co-operating with the continuously variable transmission (2); a pressure compensation chamber (22) co-operating with the above-mentioned pressure cheer (15); and a passage connection (26) connecting the pressure compensation chamber (22) with the pressure chamber (15) , wherein a pressure-sensitive passage control member (28) is provided in the above-mentioned passage connection (26).

Abstract: A retrievable packer is provided for wireline setting and tubing retrieval. A circumferentially extending shear member releases the retrievable packer from the wireline once the retrievable packer is set. A positive locking member releasably locks the upper and lower slips to the mandrel as they are wedged into gripping engagement with the casing string. The positive locking member includes a body lock ring which locks the upper slip assembly in a ratcheting engagement with the packer mandrel, and a J-latch which releasably secures the lower slip assembly to the mandrel.

Abstract: The combination of an endless power transmission belt construction and a pulley therefor, the belt construction and methods of making the same are provided, the belt construction having opposed inner and outer surfaces with each surface defining a plurality of longitudinally disposed and alternately spaced apart like projections and grooves that are adapted to mesh with a ribbed surface of a pulley, the depth of the grooves of each of the surfaces of the belt construction being substantially less than the approximately 2.4 mm depth of the grooves of a similar belt construction that is adapted to have one of the opposed surfaces thereof mesh with the ribbed surface of the pulley in the same manner as the first mentioned belt construction.

Abstract: A measuring while drilling apparatus for use in the drilling of subterranean wells comprises a plurality of interconnected tubular housings which are insertable into and removable from a drill string by a wire line. A hollow plunger on the bottom of the apparatus is vertically shiftable with respect to a fixed diameter orifice disposed in the path of the drilling fluid flow. Fluid pressure forces derived from the drilling fluid effect the movement of the plunger forward and away from the orifice to create pressure pulses which are transmittable through the drilling fluid to the surface. Sensors provided in the housings generate signals, which are converted by a downhole controller, to effect the sequential generation of the positive pressure pulses to be indicated at the surface of the well by a digital readout of the outputs of the various sensors carried in the tubular housings.

Abstract: Pulley, in particular suitable for application in a continuously variable transmission, in which an endless belt can be fitted between the discs of the pulleys, the path of which endless belt can be influenced by a cylinder/piston device. The cylinder/piston device is provided with at least one pressure chamber provided with walls, one of the walls being provided with a resilient hinge, as a result of which elastic expansion of the wall around the hinge is achieved at relatively high pressures in the pressure chamber. Therefore, the shaft, along which at least one of the discs is axially displaceable, is not clamped and deformed to a lesser extent under heavy load, so that the action of the transmission is not impeded.

Abstract: A belt tensioning system, a belt tensioner therefor and methods of making the same are provided, the belt tensioning system comprising a tensioner arm pivotally mounted to a support, and a wound coiled spring having opposed ends one of which is operatively interconnected to an abutment of the support and the other of which is operatively interconnected to the arm, the arm having a shoulder for being engaged by the one of the opposed ends of the wound coiled spring so as to permit removal of the arm and the wound coiled spring as a self-contained unit from the support when the arm is pivoted to a certain position where the shoulder of the arm engages the one end of the spring and effectively moves the one end of the wound coiled spring out of contact with the abutment of the support.

Abstract: A wellbore fluid (e.g., a drilling, completion, packer, or fracturing fluid) comprises (a) at least one additive selected from the group consisting of emulsifiers, wetting agents, viscosifiers, weighting agents, fluid loss control agents, proppants for use in hydraulically fracturing subterranean formations, and particulate agents for use in forming a gravel pack; and (b) a non-toxic white mineral oil having (i) an API gravity at 15.6.degree. C. (60.degree. F.) greater than 35, (ii) a content of compounds containing 14 or more carbon atoms of at least about 95 weight percent, and (iii) a pour point of at least about -30.degree. C. (-22.degree. F.).

Abstract: A belt tension adjusting device having a fixed member, a support shaft extending vertically from the fixed member and a pulley arm having a boss formed with a boss. The support shaft is received in the bore to rotatably support the pulley arm. A damper mechanism is mounted between the support shaft and the boss for damping a pivoting motion of the pulley arm. A pulley is mounted on the pulley arm. A tension adjusting spring is coupled to the pulley arm for biasing the pulley to impart tension to a belt. A bearing is provided for receiving radial loads produced when the pulley arm pivots. Part of the bearing is located in part outside the boss.

Abstract: A hydraulic recoil and belt tension control system is connected to a hydraulic motor of an endless belt propulsion device so that a common source of fluid is used to both drive the hydraulic motor and maintain proper tension in a drive belt of the propulsion device. The hydraulic recoil and belt tension control system includes first and second check valves to direct pressurized fluid from the appropriate one of first and second motor conduits to an actuating chamber of a belt tension actuator. A relief valve relieves excessive pressure in the actuating chamber and returns fluid exhausted from the actuating chamber during recoil through either of third and fourth check valves to the appropriate one of the first and second motor conduits. Utilizing the hydraulic motor drive circuit as the source of fluid for the hydraulic recoil and belt tension control systems eliminates at least two conduits between the propulsion device and the vehicle to which the propulsion device is mounted.

Abstract: A housing mounted to a vehicle floor is arranged to permit removal and extension of an extension member therefrom, having an extension plate pivotally mounted to the extension member to provide for a ramp structure relative to the associated vehicle. The housing is arranged to include a central plate extending from a first end of the housing to an orientation spaced from a second end of the housing for positioning and mounting of a vehicle chair thereon, with an abutment block extending from the central plate to a second side wall of the vehicle for abutment of a chair wheel, with central plate abutment members positioned on the central plate in adjacency to the first end for securing the chair between the central plate abutment members and the abutment block. Security straps are mounted to the side walls for securement of the chair to the housing top wall.

Abstract: An automatic closed loop drilling system is disclosed for providing automatic directional drilling capabilities in a bottomhole assembly. The drilling system includes at least one adjustable stabilizer that varies in response to formational and drilling conditions encountered downhole. A microcontroller is preprogrammed with a desired range of formation characteristics or with a desired inclination or target area. The microcontroller compares actual sensed data with the desired data and adjusts the position of the stabilizer blades to vary the direction of drilling.

Abstract: A method and apparatus allowing sequential production from layers in a well uses a pair of vertically spaced production assemblies formed by packer seal assembly above a respective screen assembly. The production assemblies are spaced on a production pipe string to be substantially aligned with zones to be produced. Isolation tubing allows the lower zone to be produced to depletion when the tubing is then plugged, perforated and the upper zone produced.

Abstract: A wellhead isolation tool is disclosed that is unique because the tool has no direct connection between the high pressure valve and the mandrel. Well stimulation fluids are pumped through one or more high pressure bores which communicate with a mandrel injection head that directs the fluids into the mandrel. The injection head and the mandrel are enclosed in a sealed bore and reciprocatably movable with a piston which is used to stroke the mandrel into and out of a wellhead and to lock the mandrel in an operating position wherein ports in the injection head are aligned with the high pressure bores. The tool provides superior safety features and ease of operation.

Abstract: A method of, and apparatus for, treating a well using a tool string is disclosed. The method includes the steps of supplying a predetermined amount of treatment fluid to the well; pumping fluid from the well and holding the fluid in the tool string; and releasing the treatment fluid from the tool string into the well. In a preferred embodiment, the method includes repeating the pumping and releasing steps until the well is adequately treated.

Abstract: An automatic set bi-directional apparatus for jarring an object in a well bore is disclosed. The apparatus comprises a tubular member having a portion defining an upper and lower striking shoulder, said tubular member having one end connected to a work string capable of creating a longitudinal force. A mandrel is connected to the object and the mandrel is concentrically disposed within said tubular member. The apparatus further includes a plurality of elongated members and an upper and lower ring members which serve as latch means. The mandrel further comprises a first and second grooved portion which are used for releasing the tubular member in order to deliver either an upward or downward jarring impact upon a stationary anvil.

Abstract: An annular safety system for a well produced by gas lift includes a packer, a landing nipple below the packer and an operating seal unit to which primary and secondary well tubings and a control line are connected. There is an inline valve in the secondary tubing and safety valve operated by the control line in a primary flow conduit in the operating seal unit. After the operating seal unit is inserted through the packer to automatically land and be locked in the landing nipple and the packer operated to anchor and seal in a well casing, flow passages are formed for conveying lift gas from the secondary tubing to around the landing nipple for lifted flow upward through the primary conduit and tubing. When the well is being produced by lift gas, and pressure in the control line is reduced purposely or by rupture of the control line, the safety valve operates to prevent upward lifted flow in the primary tubing.