Abstract: An apparatus suitable for growing plants comprises a tubular member enclosed on both ends by vertically oriented fittings to retain liquid therein. The tubular member has openings through a wall sized to receive a plant vine and positioned to retain liquid in said tubular member. The tubular member is preferably a transparent, plastic pipe.

Abstract: A service hatch insertable in doors and walls, with a frame insertable in an opening of a door or of a wall and a closing part connected to said frame and incorporating a service opening, whereby the closing part has a shock-proof, transparent panel, a fixing slot for fixing one edge of this panel and, on the opposite edge of the panel, a hinged handle which can be turned around a turning axle parallel to the two edges. The handle bears a support rod at a distance from the turning axle, on which support rod the neighboring edge of the panel rests.

Abstract: A closure structure for a walk-in freezer or refrigerator unit capable of being mounted into a rectangular opening, the structure comprising a U-shaped inner frame member and a U-shaped outer frame member which are connected at a mating lip and mating flange to form a C-shaped channel to receive the wall around the rectangular opening, a threshold member mounted flush with the floor and a hingedly mounted door member. The inner frame member has an insulating material mounted to correspond to the rectangular opening. Sealing may be enhanced by provision of a magnetic door gasket and metal strip. A double wiper strip on the bottom of the door is positioned to contain a heated strip mounted in the threshold.

Abstract: A side adjustable roller assembly for a sliding door comprises a housing containing a rotatable cam and a wheel carriage with a guide wheel mounted therein pivotally attached to the housing. The assembly is insertable into a recess in the edge of a door, being held therein by a slot in one end of the housing, and by a bend in a strip of spring steel attached to the housing at the other end which engage opposite ends of the recess, respectively. Contact of the cam surface with that of the wheel carriage controls the distance that the carriage can be pivoted into the recess by the door's weight, against the force of an associated spring urging the carriage away from the recess. The point of engagement of the cam surface with the carriage, and therefore the distance between the door's edge and the surface over which it is mounted, depends upon the degree of the cam's rotation, determined by adjustment of cam mounting trunions which can be accessed from the side of the housing.

Abstract: The rotating head comprises oscillating blocks 1 mounted on inclined pins 2 connected by means of connecting rods 5, the rods being mounted on eccentric pins fixed to toothed helicoidal wheels 9. The wheels mesh with a worm screw 10 having a vertical axis, the worm screw being mounted on the fixed structure of the apparatus. The entire complex is mobile at reduced speed, a fact which reduces the wear and consequently the necessity of maintenance and substitution of parts during operation.

Abstract: In a chucking apparatus for the combined grinding and honing working of a racetrack surface of a roller bearing external ring, a first chucking device comprising a pair of glide shoes and a second chucking device comprising a hydrostatic glide bearings wherein the first chucking device the grinding is integrated as a multiple arrangement into an indexable round table while the second chucking device is capable of being moved by simple axial shifting into the honing chucking device integrated into the round table.

Abstract: In a method employed by the device, the distance between a shaft (14) of a grinding wheel (13) and a shaft (5) carrying a finished glass (7) in contact with the grinding wheel, is measured by means of a microprocessor (18) controlling a shifting device (11), by bringing a tracer member (9) in contact with a template (8) mounted on the shaft (5), a standard disk (20) being mounted on the shaft (14) coaxial with the grinding wheel (13) for measuring the distance between the shaft (14) and the shaft (5) by bringing the standard disk in contact with the finished glass.

Abstract: For a hand power tool (1) with a multi-part manually operable quick-action chuck (2) for a disc-shaped tool (3) which is held on a shoulder (4) of a drive spindle (5) and onto which a force can be loaded from the other side by a pressure plate (7), with the pressure plate (7) concentrically embracing a threaded part (13) and being arranged positionally secured in relation to the threaded part and rotatable, with a hand screw part (11) embracing the threaded part (13) and th pressure plate (7) like a sleeve, and forming an annulus (14) with these, which contains at least a rolling contact bearing (9) and a drive which couples together the hand screw part (11), the threaded part (13), and the pressure plate (7), for improved function and a simplified design, and for a limitation of the maximum clamping pressure on the tool, a rolling planetary drive is formed from at least one of the rolling contact bearings (9, 12) in conjunction with a springly element (10), the drive which couples the pressure plate (7), the

Abstract: A method is provided which bonds a composite abrasive compact to a cemented carbide pin. The method includes the steps locating a braze alloy having a perforated metal material embedded therein between a surface of the composite abrasive compact and a surface of the cemented carbide pin. The braze alloy has a melting point below that of the metal material. The surfaces are urged together, the temperature of the braze alloy is raised to above its melting point and maintained at this temperature for a short period. The alloy is then allowed to cool and solidify and bond the surfaces together.

Abstract: An apparatus is provided to remove undesirable deposits on an intake valve after only partial disassembly of an engine, the apparatus including a blasting device and suction device. The blasting device directs blast media against the undesirable buildup to clean the intake valve, and includes a remote control and specially constructed pressure tank that cooperates with the remote control to improve operation, convenience and safety during use. The suction device suctions away spent blast media and dislodged deposits and includes a universal adapter to permit the device to sealingly engage an exposed air intake opening on the partially disassembled engine. The suction device also includes spreadable grippers that engage the sides of a passageway to hold the suction device in place, and further includes an arrangement for generating a vacuum by use of compressed air.

Abstract: A mobile surface abrading apparatus for cleaning and texturing the surface of horizontal, or near horizontal, structures, particularly roads, highways, airport runways and the like. Abrasive particles such as steel shot or grit are projected at the structure surface in angular relationship to abrade and etch the surface and the abrasive rebounds into one or more vertical abrasive conveyors, where it is transferred by air to a rotating screen, separated from the air, road debris and dust and recycled and repeatedly projected onto the surface to be treated. Air flow upwardly through the vertical abrasive conveyors is carefully controlled to lift the abrasive particles, as well as the dust and debris, beyond the rebound energy boundary and effect efficient recycling of the particles.

Abstract: A laminated rubber support assembly which earthquake-proofs buildings. It comprises a plurality of rigid plates arranged to alternate with rubber-like elastic plates and adapted to support a heavy object in such a manner as to allow the object to swing horizontally. This laminated rubber support assembly is characterized in that at least the peripheral region of each rubber-like elastic plate interposed between rigid plates is not bonded to the rigid plates.

Abstract: Trim piece for trench duct which can be used where the floor covering is tile or carpet. There are three outwardly extending flanges. In the tile mode, one flange is used as a tile separator and the other flanges are used respectively to support the trench cover and an edge of the floor tile. In the carpet mode, the trim is turned 180.degree. so the tile separator flange is inactive wile the other flange respectively support the edge of the floor tile and the trench cover. In the tile mode, the edge of the floor tile has vertical support so the breakage is avoided. This is attained by that the trim flange supporting the edge is in turn supported by the trench and by concrete.

Abstract: A precast concrete structure has a joint (Js) connecting together a span of two or more beams (Bx, By) supported on columns (c) in which the joint is disposed substantially at the point of contraflexure of the beams away from the support columns and includes two mating inclined faces one inclined face being formed at the end of each of the beam, the beams being connected without pretensioning across the joint.

Abstract: Process for manufacturing walls from earth and sand mortars includes making a mortar mixture containing a dry aggregate mass of between 15 and 50% by mass of earth and between 85% to 50% by mass of sand, bonding materials in a mass of at most 10% of the dry aggregate mass, and water in a mass of at most 22% of the total dry mass of earth, sand and bonding materials, stirring the mixture continuously and transferring while stirring the mixture by force into an inlet of a pump, and pumping the mixture from the pump and projecting the mixture within a framework against a vertical projection support and allowing the mixture to set.

Abstract: In the construction of buildings, multiple super-imposed plastic fastening strips are employed to affix a building member to a substrate.

Abstract: A file cabinet door is disclosed whose front carries a contrasting design or pattern. Decorative openings are provided through a front panel in the door in the form of a pattern. A decorative interior panel of contrasting appearance to the front panel is provided rearward of the front panel. A person on viewing the front panel sees a contrasting design by reason of the openings rendering the interior panel visible therethrough.

Abstract: A portable display structure comprising a number of upright columns joined by a number of horizontally extending beams, the columns and/or beams being formed in a similar manner of a central structural member made of a number of units and each unit comprising a plurality of rod elements connected at their ends to associated hubs.

Abstract: An apparatus and method for securing building construction members such as roof trusses and floor joists. A flat lacer coil fastened between gable trusses and is of sufficient tensile strength to temporarily sustain lateral tipping forces of support trusses as they are fastened to the frame of a building structure. In an alternative embodiment, the lacer coil extends between floor frame members and, when attached to floor joists, counteracts the inherent bowing when they are secured to the floor.

Abstract: A structure for limiting access, such as a storm door, having first and second polymer shells with at least one them having side shell portions extending at an angle from a major shell portion with these side shell portions adjoining the other shell, there being a first distribution of magnetic particles positioned between a polymer backing and both the first and second shells. The backing can be fused to the shells to provide a single unit outer structure with the magnetic particle distribution being substantially in the fused portion. These magnetic particles extend in the fused portion around substantially the entirety of a major shell portion. The space between the two shells in that situation can have elongated members enclosed therein which are not fastened to one another by anything extending into such members, and the remainder of this space may be filled with an expanded polymer foam.

Abstract: An improved cutting mechanism for cutting plastic netting includes a punch which is movable, toward and away from a heated anvil knife edge.

Abstract: A wrapping material for providing a decorative covering for an item wherein the wrapping material has a width and at least a first end. The first end of the wrapping material is positioned on the outer peripheral surface of the item to be wrapped and the wrapping material is wrapped about the outer peripheral surface of the item while moving the wrapping material generally over the outer peripheral surface of the item until the wrapping material covers at least a portion of the outer peripheral surface of the item.

Abstract: Stretch wrapping packaging material on a load includes introducing stretch wrap packaging material onto V shaped tips of projecting portions of a first grooved roller so that the packaging material spans the nonprojecting portions of the first grooved roller. The web of packaging material and the first grooved roller are transported in the direction generally parallel to the grooves. The web of packaging material spanning the nonprojecting portions of the first grooved roller is impinged with V shaped tips of projecting portions of a second grooved roller. The tips of the projecting portions of the second grooved roller are transported at a speed which is less than the speed of the tips of the projecting portions of the first grooved roller.

Abstract: A dispenser-container comprises a container body provided with two containing spaces, containing wet contents and dry contents, respectively. The container body is a bag constituted by a first flexible sheet made of a liquid impervious material and a second flexible sheet made of a liquid impervious material. The first sheet constitutes a bag of a pillow type, longitudinal edges of the first sheet overlap each other and are at most slightly sealed with each other to such an extent that they can be manually separated to form an opening for dispensing the dry contents. The second sheet is fixed to the first sheet along the entire peripheries thereof and is located outside or inside the pillow type bag.

Abstract: A harness 10 includes a buckle 20 for releasably securing harness strap ends 13 and 14 in one of two alternative conditions. The buckle includes a frame 21 and a pivoted clasp member 37. One strap end 13 is secured to the buckle frame. The other strap end 14 may be connected through an opening 38 between the clasp member 37 and a clamping surface 26 on the frame. The clasp 37 is normally held closed by a spring 46, operating against an eccentric clamp surface 42 on the clasp member 37. Alternatively, a spring arm of the spring 46 may be lifted, and the free end of the strap end 14 may be inserted through the buckle between the clasp member 37 and the spring arm. When released against the strap, the spring arm will hold the strap for release upon application of prescribed tension along the straps. The clasp member is mounted to the frame within angular slots to permit opening of the clasp to accept thick straps or straps of double thickness.

Abstract: An adjustment device for modifying the front of a horse blanket prevents the blanket from rubbing off hair and causing sores on the horse's shoulders and withers. The adjustment tabs are formed by sewing a first strip of hook and loop connecting material on each side of the outer facing of the blanket on a line positioned diagonally between the center of the chest and the top of the wither. A second strip of mating hook and loop connecting material is connected to the first strip. It passes through a rectangular loop and attaches back to the first strip. By pulling the second strip through the loop any desired amount, a pleat is formed in the blanket on each side of the horse on the slope of the shoulder approximately halfway between the point of the shoulder and the wither.

Abstract: A mower vehicle includes a vehicle frame and single front and rear driven wheels. First and second blade housings are pivotally connected to each other along a longitudinal axis of the vehicle frame and are attached to first and second side frames, respectively. Each side frame is pivotally attached to the vehicle frame near the rear thereof with a hydraulically retractable and extendable cylinder assembly urging each side frame downward or upward in response to changes automatically sensed in the slope of the terrain. Ground engaging outrigger wheels attached to each side frame contact the terrain and the vehicle frame is thus maintained in a generally upright position.

Abstract: A harvester for harvesting aquatic plants includes a rotatable gate. The rotatable gate subdivides a containment area which is used to hold harvested aquatic plants. The rotatable gate acts to compress harvested aquatic plants and increases harvest capacity.

Abstract: A row crop attachment for forage harvesters includes a plurality of row crop divider units arranged side-by-side on a base frame to define a plurality of crop conveying paths. Gathering chains are arranged to pass through each crop conveying path from an entrance to an exit thereof for conveying crop material through the crop conveying paths. Rotary knives are disposed adjacent the entrance of each crop conveying path for cutting off crop material before it is conveyed rearwardly through the crop conveying paths by the gathering chains. An auger is disposed adjacent the exits of the crop conveying paths for converging crop material exiting from the crop conveying paths toward a longitudinal center line of the row crop attachment. A filler ramp is positioned underneath the auger along this longitudinal center line behind the row crop divider units to prevent accumulation of crop material near the exits of the crop conveying paths.

Abstract: A harvester thresher or combine has a picking slot through which grain stalks are pulled to separate the stalks from the grain heads. Two oppositely rotated, parallel shafts are located at opposite sides of the picking slot. Each shaft has at least one cutting disk in close cutting relationship with the cutting disk of the other shaft. A vaned crusher element is mounted adjacent to each cutting disk and has its radial vanes arranged for intermeshing with the vanes of the element on the other shaft. The tips of the vanes project outward farther than the periphery of the adjacent cutting disk for assisting in pulling the stalks through the picking slot for chopping and crushing by the cutting disks and crushing elements.

Abstract: A splice assembly joins two short or broken sickle bars with their attached cutter sections. The sickle bars and cutter sections have a series of aligned holes. Top and bottom splice plates sandwich the bars and cutter sections, and have a series of openings that register with the holes in the bars and cutter sections. The outer surface of each plate is countersunk at the openings, and a plurality of bolts with conical heads are received in the countersunk openings in one plate and a plurality of nuts with conical ends are threaded onto the bolts and received in the countersunk openings of the other plate.

Abstract: A mechanical citrus and other fruit picking apparatus is defined with an improved method of picking fruit, using finger assemblies with tension producing and tension reducing abilities, with finger members protruding at intervals from sides of tubular arms. Arms are mounted on metal base frame that can be attached to various types of tractors or other propelling equipment. As arms of apparatus enter through limbs and foliage into tree, said fingers depress, then reposition to correct angle for picking fruit. Any said arm retracts upon any impact with larger limb. As apparatus is withdrawn from tree, said fingers engage stems of fruit, bringing fruit up into intersection of said arm and said finger, whereby pressure of said finger against stem causes separation of fruit from stem. During the backward motion, smaller limbs and leaves are pulled up and over the special shaping and slippery surface of said finger. The tension reduction device allows said finger to slip over larger limbs.

Abstract: A cable stranding apparatus is described as having a plurality of stranding rotor units that are interchangeably coupled, in a locked manner, to a single rotor drive assembly of such apparatus. Each stranding rotor unit is designed to accommodate the dimensions of particular cable elements to be stranded. For this purpose, the stranding rotor unit for cable elements of a large cross-section has a plurality of large collets for accommodating the drawing of such large cable elements through the unit; while the cable stranding rotor unit for cable elements of a small cross-section has a plurality of smaller collets for drawing the smaller cable elements through such unit.

Abstract: A head for a rake has a fan-shaped body with a plurality of fingers radiating from an attachment to a rake handle. The individual fingers have three portions: a base portion, a middle portion and a tip portion. The base portion of each finger is generally rectangular in profile; the middle portion is generally rectangular with the sides being arcuate outwardly; and the tip portion is a circular arc segment with the chord segment thereof comprising the proximal end of said portion. A reinforcing rib is positioned normal to the bottom surface of each portion of each finger, the reinforcing rib originating along the length of the base portion and extending continuously to the distal end of the tip portion. The head is preferably molded from a thermoplastic compound such as polyethylene, polypropylene, or polyurethane.

Abstract: A brushless DC motor-driven spindle assembly for a textile ring spinning frame wherein a shaft for rotatably supporting a bobbin for yarn collection is mounted for rotation about a central axis of rotation in a bolster section and, under certain conditions of operation, for rotation about axes which are incrementally angularly displaced from the central axis of rotation, and including rotor/stator position detecting elements comprising sensed elements mounted on the motor rotor for rotation therewith and sensing elements mounted in fixed position relative to the rotor and adjacent the path of movement of the sensed elements so as to maintain the same radial distance between the sensing elements and the sensed elements during incremental angular displacement of the axis of rotation of the shaft and motor rotor.

Abstract: In the case of an arrangement for pneumatic false-twist spinning having air nozzles arranged behind a pair of drafting units, it is provided that the air nozzles lead into a space which is designed as a V-shaped groove which, together with a covering, is completed to form a yarn guiding duct which leads from the mouth of the air nozzles to a yarn outlet opening. The yarn guiding duct is provided with a cross-sectional enlargement in the area adjacent the air nozzle outlets to provide for uniform flow in the duct.

Abstract: The invention relates to secondary power system apparatus and method for use aboard aircraft in place of conventional auxiliary power units (APU's) and emergency power units (EPU's). The invention integrated power unit (IPU) performs the function of both an APU and an EPU, while avoiding the use of hazardous monofuels. The IPU includes a turbine engine operable on pressurized ambient air, or on pressurized stored air, along with jet engine fuel. The structure of a combustion chamber for the engine which is able to use pressurized air from two separate sources; of a control able to selectively operate the engine as an EPU, as an APU, and to effect operating transition from EPU to APU; and of a composite secondary power system with the IPU are all disclosed.

Abstract: A gas turbine engine bleed air system in which air flow from a high pressure and a low pressure compressor stage of a gas turbine engine are mixed together by controlling the pressure at the outlet of a proportional valve. The pressure is controlled by modulating the flow area of the proportional valve through which the high pressure air flows in order to achieve a scheduled pressure value. The scheduled pressure value is determined as a function of a temperature error at a location downstream of the proportional valve in the bleed air system.

Abstract: A secondary power generating system and method is provided that can drive an aircraft's accessories, and deliver cooling flow and fuel flow to a propulsion engine such as a turbojet, ramjet or turboramjet. This system and method employs a heat exchanger in which high pressure, endothermic, liquid fuel absorbs heat from the air exiting the engine's compressor and as a result is transformed into a high pressure, gaseous fuel. The high pressure gas is expanded across a motor which extracts the pressure energy and converts this energy into mechanical power for driving accessories. The gas is then fed into the engine's combustor where it is ignited. The cooled air exiting the heat exchanger is returned to the propulsion engine and is used for cooling various components such as blades and shafts therein.

Abstract: During low-load operating conditions, preburner combustion products are supplied with a chemical reactant to reduce NO.sub.x. The preburner products of combustion are mixed with a hydrocarbon fuel in the presence of a combustion catalyst to ignite and initiate a catalytic combustion reaction. The preburner is then shut down. The fuel/air mixture supplied the catalytic reactor bed during the mid-load operating range of the turbine is sufficiently lean to produce a combustion reaction temperature too low to produce thermal NO.sub.x. Thus, at low-load conditions, preburner combustion occurs with NO.sub.x reduction by chemical reactant, while the catalytic combustion occurs at mid-range operating conditions at temperatures too low to produce NO.sub.x. For high-load operating conditions, the catalytic combustion occurs as previously described and additional lean fuel/air mixture is supplied the reaction zone whereby thermal NO.sub.x is likewise avoided.

Abstract: A coal fired gas turbine system with an integral topping combustor is provided for generating rotating shaft power by consuming coal. A carbonizer converts coal to a char and a gas fuel. The char is burned in a pressurized fluidized bed combustor (PFBC) supplied with compressed air from a gas turbine. The hot gas from the PFBC is directed to a topping combustor for further heating by burning the gas fuel produced by the carbonizer. The topping combustor is comprised of a plurality of cylindrical combustor cans disposed within a cavity formed by the gas turbine casing between the compressor and turbine sections. A perforated baffle disposed in the cavity creates a plenum so that the hot gas entering the casing through four pipes arranged about its periphery is uniformly distributed among the combustor cans.

Abstract: A stationary reactor is provided having a disc-shaped combustor having a top plate and a bottom plate spaced apart from each other. The space between the plates defines a combustion chamber having a center and a periphery, the space tapers at the periphery of the chamber. Ignition is provided centrally located in the chamber. An air intake supplies an explosive mixture to the chamber which ignites to cause expansion. The combustion chamber has a peripheral aperture defined by the space between of each of the plates at the periphery of the chamber, the aperture allows the expanded mixture to be discharged from the chamber in a substantially circumferential manner.

Abstract: An aft fan gas turbine engine comprises a coaxially related compressor, compressor turbine, fan turbine, and aft fan. An annular fuel tank is disposed about the compressor and an annular combustion chamber is disposed between the compressor and turbine.

Abstract: The present invention features an automotive catalytic converter accessory device for improving its efficiency and operational life. The accessory device comprises a housing disposed in the manifold exhaust pipe, upstream of the catalytic converter. The housing contains a hollow conduit that conveys the exhaust gases of the manifold to the entrance or interface of the catalytic converter. The conduit comprises a plurality of injection orifices or a continuous annular orifice disposed about the periphery thereof. The orifices introduce air into the conduit passage. The air enters the conduit at spaced-apart, tangential angles with respect to the axis of longitudinal flow of the automotive exhaust gases. This causes a dynamic mixing of both air and exhaust gas, wherein both fluids begin to mix and swirl with respect to the flow axis. The swirling mixture then enters the catalytic converter, where by reason of its centrifugal action, the mixture is caused to expand into the wider converter cavity.

Abstract: An exhaust outlet is disclosed, characterized by the presence of an intermediate expansion chamber (4) situated between a collector tube (3) and an outlet tube (5). The intermediate expansion chamber (4) comprises a first portion (6) with divergent walls and a second portion (7) with convergent walls. A discharge orifice (9) is formed in the central zone (8) of the expansion chamber. The expansion chamber (4) captures the particles brought by the gases and discharges them through the discharge orifice (9).

Abstract: A valve having a housing including an inlet, an outlet, an internal passage connecting the inlet and the outlet, a pressure responsive member movably supported by the housing for opening and closing the internal passage, and a spring located between the member and the inlet for biasing the member away from the inlet.

Abstract: Disclosed is a hydraulic control valve system, for driving a plurality of hydraulic actuators by a single pump, including pressure compensation valves and a shuttle valve disposed in a vertical bore orthogonal to a lateral bore of a valve body, into which a spool of a direction switching valve is fitted. A load sensing chamber for introducing a load pressure of an actuator is formed at an intersection between the lateral bore and the vertical bore. An opening-side first pressure receiving surface of the pressure compensation valve confronts the load sensing chamber. The pressure compensation valve has an opening-side second pressure receiving surface contacting a pilot pressure in the vicinity of the opening-side first pressure receiving surface. Formed on the upper side of the pressure compensation valve are a closing-side first pressure receiving surface on which a bridge pressure acts and a closing-side first pressure receiving surface on which an external control pressure acts.

Abstract: In a hot gas or Stirling engine conventional regenerators for engines with a large displacement, designed for axially directed flow and usually lacking sufficient mechanical strength with respect to the high working gas pressures, have been replaced by radial flow regenerators. In the respective receiving spaces, the radial flow regenerators are surrounded externally and internally by an annular duct for the supply and discharge of the working gas. Thus, it is possible to ensure a larger flow area for the working gas and to design the engine with the desired mechanical strength.

Abstract: A caging arrangement for limiting the extension of springs in a bore. The caging arrangement includes cylindrical members which are connected to pistons in a master cylinder. The cylindrical members which are joined to the pistons and communicates the force of piston return springs to urge the pistons toward a rest positions while a valve return springs retained by the cylindrical members urges valves toward stops to control fluid communication between a reservoir and pressure chambers associated with the pistons.

Abstract: An arrangement and process for adjusting a supply valve closing in a tandem piston master cylinder is disclosed. The tandem piston master cylinder includes a piston stroked by engagement with an operating rod and a spaced floating piston driven by an interposed return spring, the floating piston captured by the rod engaged piston during the return stroke by a headed screw abutting a projection at the end of a bore within the screw head moves during relative movement between the pistons. Supply valves are opened and closed by the position of each piston. The piston relative positions are adjusted to achieve proper supply valve closing by rotation of the rod engaged piston while fixing the floating piston against rotation which rotates the screw thread which also slightly varies the precompression of the return spring. This adjustment selectively controls the point of closing of the supply valve associated with the floating piston relative the position of the rod operated piston.