Showing papers on "Piston published in 1996"

Force-developing device for cutting forceps

Abstract: A force-developing device for forceps of the type equipped with two jaw elements (2, 3) and with two handles (4, 5) includes a jaw (6A). A link rods system (6B) is articulated with the jaw (6A). A front end of a piston (7) is connected to the link rods system (6B). The piston is housed slidingly inside a first handle (4). A yoke (8) is provided for holding the second handle (5) relative to the first handle (4). A pair of complementary racks (9) mechanically drive the piston (7), the pair being borne by each of the two handles (4, 5). A trigger catch and a rack for preventing the return of the piston are borne by the first handle (4). The pair of complementary racks (9) for driving the piston (7), the trigger catch, and the rack acts alternately on the piston so that by successively moving the second handle (5) towards and away from the first handle (4), the piston (7) is moved forwards and the jaw (6A) is deformed by means of the link rods system (6B). The successive movement brings the two jaw elements (2, 3) towards each other.

Needleless connector valve

Abstract: A valve mechanism for a needleless connector employs a deformable piston having a piston head of elliptical cross-section with a marquise-shaped bore formed along its longitudinal axis wherein the major axes of the respective generally elliptical shapes are oriented perpendicular to one another. The piston head is captured within the connector housing and is reciprocal between a section of reduced diameter adjacent the connection port and a section of enlarged diameter. Constraining the piston head into the section of reduced diameter causes the elliptical bore to be squeezed shut while positioning the piston head in the section of enlarged diameter causes the piston head to relax and assume its natural elliptical shape, while the bore similarly regains its natural open shape to provide a fluid path therethrough. A compressible or extendible section affixed to the piston head serves to bias the piston into the section of reduced diameter. A tapered section of the piston contacts the housing to secure the top of the piston flush with the top of the housing for ease in cleaning.

Device of miniaturised construction for producing high pressure in a fluid to be atomised

Abstract: A miniaturised device for producing high pressure in a fluid imposes stringent requirements on the manufacturing process. The device according to the invention consists of a hollow piston (57) displaceably mounted in a cylinder and a valve member (58) which is guided by the hollow piston (57) and mounted so as to be axially movable relative to the hollow piston (57). The valve member (58) is arranged at one end of the hollow piston (57) inside or immediately in front of the end of the hollow piston (57). The device is used in a mechanically operated high pressure atomiser. This consists of a two-part housing which comprises a pump housing (52) with nozzle (54), a blocking mechanism (62), a spring housing (67) with spring (68), a non-pressurised storage container (71) for the fluid (72) and a mechanical counter integrated in the spring housing (67). The valve (58) operates without any auxiliary force, closes very rapidly and is sealed tight against high pressure. The atomiser is safe and simple to operate and environmentally friendly. The fluid is metered extremely accurately. The atomiser is used, for example, to produce an inhalable aerosol of a liquid medicament without the use of a propellant gas, at 320 bar, for example.

Lumped parameter models for the interpretation of environmental tracer data

Abstract: Principles of the lumped-parameter approach to the interpretation of environmental tracer data are given. The following models are considered: the piston flow model (PFM), exponential flow model (EM), linear model (LM), combined piston flow and exponential flow model (EPM), combined linear flow and piston flow model (LPM), and dispersion model (DM). The applicability of these models for the interpretation of different tracer data is discussed for a steady state flow approximation. Case studies are given to exemplify the applicability of the lumped-parameter approach. Description of a user-friendly computer program is given. (author). 68 refs, 25 figs, 4 tabs.

Hybrid electric vehicle

Abstract: A hybrid electric vehicle which is driven by a motor (7) powered with electric power generated by an engine (1), wherein the cylinder, piston, and sub-combustion chamber of the engine have insulation structure so that heat sufficient for evaporating fed fuel is held in the sub-combustion chamber. The sub-combustion chamber having a central communicating orifice is formed on the central portion of the piston head, a fuel collision table is formed in the sub-combustion chamber, and a plurality of radial communicating orifices for jetting flame from the sub-combustion chamber against the cylinder is provided, the burning is easy even with using a low pressure fuel injection mechanism, therefore a solenoid valve type injection pump with simple structure is used, the burning is smooth with using alcohol fuel such as methanol and ethanol, the fuel injection timing is adjusted dependently on load to the optimal timing, the number of working cylinders is controlled so as to match to the load, the control allows the engine to operate at the optimal fuel consumption, therefore emission of hazardous substance contained in exhaust gas is minimized. The engine of the present invention needs no cooling mechanism, and also needs no heavy gear box and no clutch mechanism, the weight of the whole vehicle is significantly reduced comparing with conventional vehicles, the fuel consumption is reduced also in terms of the light weight.

Piston based ventilator

Abstract: A piston based ventilator for delivering breathing gas to the lungs of a patient, and more particularly a piston based ventilator that delivers breathing gas to a patient upon longitudinal movement of a piston rod and associated piston head within a piston cylinder. The piston rod is centrally located within the cylinder and moves along the cylinder in response to direct drive from a motor to move the piston head within the cylinder and displace a volume of gas to be delivered to the patient.

Filter assembly with automatic shut-off and quick-connect filter cartridge

Abstract: Embodiments of a fluid filtering assembly are shown and described, each embodiment including a valve head that routes fluid to and from a filter cartridge and that includes a valve system that automatically opens and closes when the filter cartridge is inserted and removed, respectively. The valve system preferably includes a generally-cylindrical piston with a hollow interior space, which receives a stem member. The stem member has a bottom-end seat or sealing member and has a central body shape that allows fluid to flow up through the piston interior space, either through or up around the stem member. Upon removal of the filter cartridge, the piston is biased to move down into an "off" position, to close both the inlet and outlet fluid passages. In this "off" position, the piston exterior surface blocks off radial fluid inlets and the piston interior surface seals with the stem bottom end seat to prevent fluid backflow out of the piston interior space. The filter cartridge preferably includes a neck with a centrally-located, vertical fluid outlet hole surrounded by a ring of vertical fluid inlet holes near the outer perimeter edge of the neck.

Percussion drill assembly

Abstract: A compressor piston divides a first compartment into two compression chambers, while a hammer piston divides a second compartment into two drive chambers, each of the compression chambers being connected to a respective one of the drive chambers to form a closed fluid system wherein reciprocation of the compressor piston causes cyclic compression and expansion of the fluid in the compression chambers and thus in the drive chambers, to effect a cyclic impacting of the hammer piston with a bit adapter connected to the drill bit. A mud motor rotates a shaft to drive an oscillator which reciprocates the compressor piston. The oscillator can comprise roller elements in the compressor piston in engagement with canted grooves in the shaft. While drilling mud drives the motor and then passes downwardly to flush the drill bit and the borehole, the drilling mud is isolated from the closed fluid system. The bit adapter slides axially, so that when the drill bit is not in contact with a borehole bottom, the bit adapter and the hammer piston move downwardly to a position where the two drive chambers are in direct communication such that the reciprocation of the compressor piston does not actuate the hammer piston. Each of the pistons is an annular piston having a bleed passageway between its chambers, permitting the chambers to equalize when the pistons are stationary. The superatmospheric pressure is such that the hammer piston reciprocates at a frequency within ±20% of natural resonant frequency.

Device for dispensing an air-liquid mixture, in particular foam, and operating unit intended therefor

Abstract: Device for dispensing an air-liquid mixture, such as foam, comprising a liquid container and an operating unit (1), which unit comprises at least a concentric air pump (2) and liquid pump (3), which each comprise a piston chamber (4, 9) with a piston (5, 10) which is displaceable therein and an inlet and discharge, and operating component (11) for operating the two pumps (2, 3), which component is integral with the liquid piston (10) and comprises an outflow channel (15) with a dispensing opening, while shut-off means, which make it possible to suck up air or liquid, respectively, and dispense them, are present in the inlet and discharge of the pumps (2, 3), the air pump (2) comprising a double-acting shut-off device which can be operated actively by the operating component (11) and shuts off both the inlet of air to the air pump (2) and shuts off the discharge of air therefrom, and the air piston (5) is an air piston (5) which can be moved freely at least over a small distance with respect to the operating component (11).

Linear indexing apparatus and methods of using same

Abstract: A linear indexing apparatus and associated methods of using same provide convenient operation of tools in a subterranean wellbore In a preferred embodiment, a linear indexing apparatus has an outer tubular housing and a tubular mandrel axially slidably disposed within the housing Two sets of slips are utilized to incrementally displace the mandrel relative to the housing A piston associated with one of the sets of slips permits the mandrel to be incrementally indexed in response to a series of repeated applications of a predetermined differential pressure

Automated pipetting of small volumes

Abstract: The device is useful for automated pipetting of small volumes of liquid. It comprises: A) a diluter (1) with a syringe (2) and a valve (3), said syringe (2) comprising a piston (11) and a piston drive (9); B) a pipetting needle (4); C) a tubing (5) connecting said diluter (1) with said needle (4); and D) an impulse generator (6) acting on the liquid in the device.

Active suspension system

Abstract: In accordance with the teachings of the present invention, a hydraulic actuator is described which is operable to generate forces. The hydraulic actuator includes a pressure cylinder as well as a piston disposed within a pressure cylinder and being operable to divide the pressure cylinder into first and second portions. The hydraulic actuator also includes a piston rod mechanically communicating with the piston and being operable to impart movement to the piston. Finally, the hydraulic actuator includes variable restriction valves for controlling the pressure on both sides of the piston substantially independent of the velocity of the piston within the pressure cylinder.

Fastener-driving tool

Abstract: Fastener-driving tool a cylinder (11), Is a drive piston (12) (11) reciprocable in the cylinder connected to a drive element (15) can be driven by the fastener elements when the drive piston (12) is moved in a driving direction, and a gas chamber (14) delimited in the cylinder for receiving a gas, and a drive means (4, 7, 10, 18, 20, 23) for movement of the drive piston (12) from a first to a second position in an opposite extending transversely to the driving direction, to thereby compress the gas present in the gas chamber, wherein the drive means is operable such that a movement of the drive piston in the driving direction due to the generated by the compressed in the gas chamber gas air pressure is possible, when the drive piston reaches the second position, and the drive means comprises a motor (4) and a drive mechanism ( 10, 18, 20, 23) which between the motor (4) and the drive piston (12) and converts the motor rotation into a movement of the drive piston from the first to the second position, characterized in that the drive mechanism (10, 18, 20, 23) an intermediate member (10) relative to the cylinder (11) correspond in the cylinder axis direction between a third and a fourth position, with the first and the second position of the drive piston (12) is movable, a biasing means (18) for biasing the intermediate member (10) along the axial direction to the third position, an engaging means (20) for producing an engagement between the drive piston (12) and the intermediate element (10) during the movement of the intermediate member (10) from the third to the fourth position, and a release means (23), through which the engagement means (20) can be disengaged when the intermediate element (10) reaches the fourth position.

Downhole tool actuating mechanism

Abstract: The invention relates to actuation of a downhole tool by hydraulic forces in a structure that does not employ lateral openings through the wall of the tool. By a variety of mechanisms, the tool wall is urged to flex preferably within its elastic limits. The wall flexing either signals a sensor which senses such motion to create a corresponding signal which can unlock a piston. Thereafter, hydraulic pressure differences are employed to move the piston to operate the downhole tool.

Hand-held printer and method for adhesive tape

Abstract: Hand-held printing apparatus and method are disclosed that provide a replaceable ink cartridge with an ink reservoir defined therein to store wet ink that may typically have a paste like consistency. A piston movable within the ink cartridge is operably connected to the tape spool for compressing the wet ink through a nozzle of the ink cartridge onto the first of a series of printing rollers that smooth out the ink for transfer to a printing roller to effect offset printing of a desired image onto the adhesive side of clear adhesive tape. The cartridge is provided in a low cost throw away package for disposal after the ink is depleted. Multiple color logos or images can be printed by using two to four different color ink cartridges. The flow of wet ink may be controlled by gearing, relative size adjustment of the components, pneumatic pressure control, adjusting or altering start/stop position of components, or increasing the number of actuating components that actuate each pumping action per revolution of the tape spool.

Formation tester with improved sample collection system

Abstract: This invention provides a formation evaluation tool for collecting a formation fluid in a chamber at a predetermined pressure and for maintaining the pressure of the collected fluid at a desired level during the retrieval of the chamber to the surface. The formation fluid is pumped into the chamber while a piston exposed to the hydrostatic pressure maintains the chamber pressure at the hydrostatic pressure. During retrieval of the chamber, the pressure in the chamber is maintained at a predetermined level by pumping wellbore fluid to the piston. A control unit at the surface is utilized for controlling the operation of the formation tool.

Linear motor compressor and its application in cooling system

Abstract: A compressor (10; 100; 200; 300; 500) with a build-in reciprocating motor, comprises a cylindrical housing (20; 120; 210; 510) with two ends thereof fitted with tow opposing electromagnets (30; 130; 230; 530), each has a circular inner pole (36; 136) and a coaxial annular outer pole (34; 134) A free piston (50; 150; 250; 560; 600) is disposed in the housing between the two electromagnets, dividing the interior of the housing into two chambers (I, II) The piston carries permanent magnets (40; 140, 145; 561; 610), providing inner and outer poles (44, 46; 141, 146) which have conical surface portions (43, 49; 141, 146) complementary with the corresponding poles (34, 36; 134, 136) of the electomagnets Sliding pole pieces (630 and 660) can be used to increase the stroke length and reduce the piston's total weight Valves (61, 63, 65; 161, 165) are fitted to form one-way flow passage connecting the inlet and the outlet of the compressor In operation, the complementary surfaces of the electromagnets and the permanent magnets form concentric forces which drive the free piston axially while keeping it magnetically suspended, so as to minimize the frictional resistance to the piston's movements and to reduce its wear to minimum Buffer mechanisms, including air, spring and/or magnetic cushioning, are formed between the piston and each of the electromagnets to prevent direct physical impact between them A movable support (280; 580) provides automatic adjustment of piston's stroke length in response to changes of output pressure A circuit (285, 283, 212, 211, 221) is formed to circulate a lubricant for keeping the piston lubricated Magnetic coupling arrangement (570, 545, 555) is made to further improve the compressor's energy efficiency In application, a number of the compressors can be connected in series to build up a high pressure output

Precision high pressure control assembly

Abstract: A precision high-pressure control assembly for supercritical fluids comprises a continuous flow system having a pressure control loop which includes a source of fluid communicating with a piston driven pump. A pressure sensor monitors the pressure of the supercritical fluid in the outlet line of the pump. A pressure controller has an input for receiving a signal relating to the pressure sent by the pressure sensor and the pressure controller yields an electronic output signal to an electropneumatic regulator. A source of air communicates with the electropneumatic regulator to provide pressurized regulated driver air directed to the pump. The electropneumatic regulator controls the regulated driver air pressure of the pump in accordance with the signal received from the pressure controller. The piston head of the pump is in a cryogenic chamber to minimize flash and cavitation.

Flow control for beverage dispensing valve

Abstract: A piston based flow control is shown for use in a high flow beverage dispensing valve. The piston thereof includes a top perimeter edge structure that allows for continuity of liquid flow during high flow applications and particularly during the initiation of a high flow dispensing so as to eliminate chattering of the pistons.

Method for compressing gases using a multi-stage hydraulically-driven compressor

Abstract: A method of compressing a compressible fluid, using a hydraulically driven compressor comprising a precompressor, a first cylinder, and a second cylinder. The precompressor receives a low pressure input of compressible fluid and fills the first cylinder to a precompressor output target pressure. A piston within the first cylinder then forces the compressible fluid into the second cylinder. This cycle is repeated until the second cylinder is filled to a first-cylinder output target pressure, whereupon a piston within the second cylinder forces the compressible fluid out of the second cylinder as a high pressure compressible fluid output, typically into some sort of storage vessel. This cycle is repeated until the compressible fluid output pressure reaches a second-cylinder output target pressure. Pressure and position sensors may be employed to provide signals to a controller, which in turn provides signals to hydraulic fluid control valves which control operation of the precompressor, the first cylinder, and the second cylinder.

High Pressure Experimental Methods

Abstract: This book is a worthy addition to the literature on high-pressure techniques. Unlike earlier books, it emphasizes diamond - anvil cells, which are useful in the range from 1 kbar to multi-megabar pressures, while not neglecting the older techniques (piston - cylinder etc) which give much lower maximum pressures but in much larger volumes. The author take a refreshing approach to the design of equipment. Both for diamond - anvil cells and for piston - cylinder equipment, he starts from the sample and works outwards, thus achieving miniaturization almost effortlessly - and for piston - cylinder equipment, miniaturization is an important safety feature. Some methods have been developed further in Russia than elsewhere, such as toroidal anvils, and the descriptions of these are very interesting. Measurement of pressure is covered thoroughly, as are methods of establishing the pressure environment (choice of hydrostatic medium, cryogenic work down to millikelvins and high temperature). The last section of the book describes some optical and magnetic measurements that can be made, primarily in the diamond - anvil cell. Eremets concentrates on the techniques which are more difficult (Brillouin and Raman scattering) or more complicated (refractive index). The brief section on magnetic measurements includes susceptibility as well as electron and nuclear magnetic resonance. As elsewhere in the book, one feels that the author has himself done these experiments and is giving the reader key information needed to overcome the practical difficulties. Every laboratory using high pressure should buy this book to complement earlier books which have a different emphasis. Anyone who wants just one text, perhaps because high pressure might be useful, should certainly choose this one.

Aircraft engine fuel system

Abstract: A fuel system for a gas turbine aircraft engine including a ecology valve and a flow divider valve, both of simple and compact construction. The ecology valve is connected to the fuel manifolds supplied by the splitter valve, and serves to suction fuel from the fuel manifolds upon engine shutdown. The fuel is temporarily stored in reservoirs in the ecology valve and upon the next engine operating cycle, is returned to the manifold so that it can be burned. The splitter valve is of simplified light-weight construction and includes a single piston operated in two regions, a first for modulating primary and second flow depending on fuel pressure, and a second region for providing a fixed, port geometry determined split between the primary and secondary.

Hydraulic shock absorber

Abstract: PURPOSE: To make confortableness and stable steering compartible with a simple constitution, on a hydraulic buffer for generating an attenuation force by using a leaf valve, etc., arranged in a piston. CONSTITUTION: A hydraulic buffer provided with a piston 4 for partitioning the inside of a cylinder 3 to an upper liquid room 6 and a lower liquid room 7 is provided with an extension side disc valve 23 for attenuation force generation provided in the piston, a coil spring 25 for energizing the extension side disc valve 23 by a prescribed set load and a lower spring support member 27 constituted movable in a direction for increasing an energizing force for the extension side disc valve 23 of the coil spring 25. Further, it is provided with an energizing force increase liquid room 29 for moving and energizing the lower spring support member 27 in a direction, by which set load is increased, by operation liquid communicating with the upper liquid room 6 through a squeezed passage 28 and flowing in from the squeezed passage 28.

Valved Piston arrangement for an electric motor driven air compressor

Abstract: An air compressor including a cylinder, a motor, a reciprocating mechanism coupled to the motor, a compression mechanism reciprocated in the cylinder by the reciprocating mechanism to compress air, the compression mechanism including a base having a coupling bolt, a compressible conical piston holder and a compressible conical piston mounted around the coupling bolt of the base, wherein the coupling bolt of the base is inserted through the center holes of the compressible conical piston holder and compressible conical piston, having a head stopped above the compressible conical piston holder and the compressible conical piston, and a retainer rod raised from the head; a valve flap is slidably mounted around the retainer rod which opens the air passage through the compression mechanism during its down stroke, and close the air passage during its upstroke; a cap is mounted on the retainer rod to limit upward movement of the valve flap relative to the retainer rod.

In-cylinder injection internal combustion engine

Abstract: This invention relates to an in-cylinder injection internal combustion engine. A recessed portion (22A) is arranged in a top wall of a piston (22) to promote formation of a vertical swirl so that a flow of inducted air introduced into a combustion chamber (27) of the engine is caused to advance from a lower wall (21A) of a cylinder head (21) of the engine toward the top wall of the piston (22) and then to advance backward from the top wall of the piston (22) toward the lower wall (21A) of the cylinder head (21). A corner of the recessed portion (22A) is formed blunter at an outlet side of the vertical swirl than at an inlet side of the vertical swirl. In the in-cylinder injection internal combustion engine in which fuel is injected directly into the combustion chamber (27), it is possible to achieve inter alia a high gas mileage by allowing a lean air-fuel mixture to undergo stratified combustion and also a high power output when a gas-fuel mixture richer than the lean air-fuel mixture is burnt. A high-efficiency internal combustion engine can hence be provided.

Metering valve for metering a fluid

Abstract: A metering valve for metering a fluid for a fuel injection valve for internal combustion engines, with a hydraulic displacement amplifier for converting the actuating displacement of a piezoelectric actuator into an increased stroke of the valve needle. Integrating the displacement amplifier spatially into the valve housing in an "O valve" to give a small overall volume is served by providing the lifting piston of the displacement amplifier with an end section of reduced diameter which projects into a recess in the operation piston of the displacement amplifier. A Belleville spring lying in the amplifier chamber bounded by the pistons presses the operating piston against the actuator, and a helical compression spring arranged in the recess concentrically to the end section presses the lifting piston against the valve needle.

Mechanics of collisional motion of granular materials. Part 3. Self-similar shock wave propagation

Abstract: (Received 2 November 1994 and in revised form 29 December 1995) Shock wave propagation arising from steady one-dimensional motion of a piston in a granular gas composed of inelastically colliding particles is treated theoretically. A selfsimilar long-time solution is obtained in the strong shock wave approximation for all values of the upstream gas volumetric concentration v,. Closed form expressions for the long-time shock wave speed and the granular pressure on the piston are obtained. These quantities are shown to be independent of the particle collisional properties, provided their impacts are accompanied by kinetic energy losses. The shock wave speed of such non-conservative gases is shown to be less than that for molecular gases by a factor of about 2. The effect of particle kinetic energy dissipation is to form a stagnant layer (solid block), on the surface of the moving piston, with density equal to the maximal packing density, vM. The thickness of this densely packed layer increases indefinitely with time. The layer is separated from the shock front by a fluidized region of agitated (chaotically moving) particles. The (long-time, constant) thickness of this layer, as well as the kinetic energy (granular temperature) distribution within it are calculated for various values of particle restitution and surface roughness coefficients. The asymptotic cases of dilute (v, 6 1) and dense (v, - vM) granular gases are treated analytically, using the corresponding expressions for the equilibrium radial distribution functions and the pertinent equations of state. The thickness of the fluidized region is shown to be independent of the piston velocity. The calculated results are discussed in relation to the problem of vibrofluidized granular layers, wherein shock and expansion waves were registered. The average granular kinetic energy in the fluidized region behind the shock front calculated here compared favourably with that measured and calculated (Goldshtein et al. 1995) for vibrofluidized layers of spherical granules.

Road vehicle-actuated air compressor

Abstract: A vehicle or pedestrian operated air compressor which utilizes flaps mounted in pairs in a road or pedestrian walkway surface. When traffic moves over the flaps, they move downward to activate a piston which compresses air. The compressed air can be stored in a container and used as needed to generate electricity or activate other machinery.

Motor vehicle steering column safety device

Abstract: A collapsible steering column for a motor vehicle has an elongated hollow cylinder slidably mounted on a piston while also fast to the piston for rotary movement. The space between the interior wall of the cylinder and the piston is sealed in a gas-tight fashion. A head is attached to the top of the cylinder. The head has a frangible seal hermetically secured inside it so that the top of the piston, the interior wall of the cylinder and the seal define an air cavity. The cavity is under pressure such that the cylinder is supported by a column of pressurized gas. A coil spring inside the cylinder urges the piston and the bottom of the cylinder apart. The seal has a bore in which resides an explosive compound. Lead lines connect the explosive compound with an electronic collision sensor, which is located in the front of the vehicle. When a collision occurs, the sensor sends an electronic signal which ignites the explosive compound and fractures the seal permitting the gas to escape from the cavity causing collapse of the cylinder. The vehicle's steering wheel is secured to the top of the head, and the piston is connected by way of appropriate linkages to the front wheels of the vehicle so that axial rotation of the cylinder, by way of the steering wheel, causes the front wheels to turn in accordance with normal vehicle operations. An air bag stowed in the steering wheel may be connected to the top of the head to capture the air released from the cavity providing additional protection to the occupant.