Showing papers on "Piston published in 1988"

The membrane diamond anvil cell: A new device for generating continuous pressure and temperature variations

Abstract: A new design for a diamond anvil cell is described. Its main originality is that the force on the piston is generated by pressurized helium, which pushes an annular membrane. It specially permits fine control and adjustment of the force Applied to the anvils, spatial stability of the sample under varying pressure, axial thrust and large optical aperture on both sides of the cell. Selected applications are presented.

Lung ventilator device

Abstract: Ventilation to a patient is provided in response to patient effort. The free flow of gas from a piston, or similar air source, in response to patient inhalation is detected, the instantaneous rate and volume of flow are measured and the measurements are used as control signals to a drive motor for the piston to move the piston to generate a pressure which is proportional to the sum of measured and suitably amplified rate and volume of flow signals. Since the command signal to the pressure generator only changes subsequent to, and not in advance of, a change in flow and volume, the ventilator is subservient to the patient and provides a proportional assist to patient ongoing breathing effort during inspiration (Proportional Assist Ventilation, PAV).

Hypodermic syringe assembly

Abstract: A hypodermic syringe assembly includes an elongated container and a cup shape molded piston longitudinal movable in the container. The container has a sidewall, a needle receiving end, and a piston receiving end which terminates in a rim. The piston has an open rear end with at least three equally spaced integral hinged tabs therearound. The piston has a first position partially inserted at the container rear where the tabs extend radially outward from the container adjacent its rear end. The piston in this position can receive a disc shaped plunger head. The piston has a second position fully inserted in the container where the tabs are rotated about their hinges and extend radially inward within the container. In this position the piston tabs hold a disc shaped plunger head within the piston. The piston has a third position partially extended out of the rim of the dispensing container. In this position the tabs are rotated about the hinges and extend radially outward sufficient to permit the plunger head to withdraw from the piston. The sidewall of the dispensing container holds the tabs in a radially inward position in all fully inserted longitudinal positions of the piston.

Arc plasma torch and method using contact starting

Abstract: An arc plasma torch (10) includes a moveable cathode (14) and a fixed anode (16) which are automatically separated by the buildup of gas pressure within the torch after a current flow is established between the cathode (14) and the anode (16). The gas pressure draws a nontransferred pilot arc to produce a plasma jet. The torch (10) is thus contact started, not through contact with an external workpiece, but through internal contact of the cathode and anode. Once the pilot arc is drawn, the torch may be used in the nontransferred mode, or the arc may be easily transferred to a workpiece. In a preferred embodiment, the cathode (14) has a piston part (48) which slidingly moves within a cylinder (50) when sufficient gas pressure is supplied. In another embodiment, the torch is a hand-held unit and permits control of current and gas flow with a single control.

Cycle-Resolved Laser-Velocimetry Measurements in a Reentrant-Bowl-in-Piston Engine

Abstract: Cycle-resolved measurements of in-cylinder air velocity have been made in a motored engine (600-r/min engine speed, 10.6:1 compression) having a high-squish reentrant-bowl piston. The velocity fluctuations have been analyzed both by low-pass/highpass frequency filtering and by evaluation of non-stationary velocity autocorrelation functions. These two complementary analyses and general issues pertaining to their interpretation are carefully examined

Dosing device for controlled injection of liquid from a reservoir into an organism

Abstract: A dosing device of the type which can be implanted in a patient to control injection of liquids from a reservoir into the patient has an electrically controllable piston pump and a circuit responsible for controlling and monitoring the operation of the pump. The circuit includes a unit for acquiring a chronological curve representative of the piston motion, and electrical signals proportional thereto are obtained. These signals are supplied to control elements which compare these signals to prescribed rated values, and generate control and alarm signals given deviations of the incoming signals from the rated values.

Needleless hypodermic injector

Abstract: A needleless hypodermic injector has a first sub­stantially cylindrical section (A) and a second substantially cylindrical section (B) movably mounted in a first end of the first section. The first section (A) comprises a hollow cylinder (44) defining a chamber for a substance to be administered, the chamber having therein an externally communicating orifice (55) at a second end of the first sec­tion and a piston (47) slidably mounted in the hollow cylinder. The second section comprises spring means in the form of a coil spring (16) and a plurality of disc springs (17) arranged in an axial row for driving the piston in the first section from a retracted position in which the hollow cylinder contains the substance to be administered to an extended position in which the substance is substantially com­pletely discharged through the orifice from the chamber. A bushing (18) is slidably mounted between the piston (47) and the spring means and is capable of engaging the piston as it travels from the retracted position to the extended posi­tion. Latch means (21,22,23,24) are also provided for locking the bushing and thereby the compressed spring means in the retracted position. With the above arrangement, when the latch means is released from the bushing, the compressed spring means rapidly impacts the bushing against the piston to provide a first, high skin piercing pressure to the substance to be discharged through the orifice and thereafter moves the piston to the extended position at a second, lower discharge pressure. The coil spring remains under substantial compression at the extended position and sufficient disc springs are present to ab­sorb recall energy caused by the piston bushing suddenly reaching the extended position.

Hand-held pneumatic power assisted syringe

Abstract: A hand-held manually operable-pneumatic power assisted syringe serves for injection of fluids. The syringe includes a barrel-shaped housing having a piston slidably mounted therein between the distal and proximal ends of the housing and dividing the housing into a fluid chamber at the distal end and a gas chamber at the proximal end. A nozzle is mounted on the distal end of the housing and is provided with a discharge passageway for discharging fluid from the fluid chamber as the piston is displaced toward the distal end. A piston push rod extends from the piston and is slidable through an end cap mounted on the proximal end of the housing with the push rod serving to displace the piston in the distal direction. The push rod is hollow and has a first passageway at a location adjacent the piston for communication with the gas chamber and a second passageway at a location exterior of the housing for communication with a source of pressurized gas to thereby fill the gas chamber with pressurized gas. A valve assembly is carried by the push rod and includes a bobbin slidably mounted within the push rod between a normal valve closed position for blocking the second passageway to a valve open position for permitting gas to flow through the second passageway into the push rod and then to the gas chamber.

Air spring damper for vehicle suspension

Abstract: An air spring damper used in a vehicle suspension system with upper, intermediate and lower chambers and incorporating a reservoir tube which has an anti-friction rod guide and bearing assembly therein which lubricates the hollow rod of a piston as it strokes in their reservoir tube in jounce and rebound An elastomeric air sleeve is featured which is connected to a top mount fastened to the vehicle body An elastomeric isolator of this mount pivotally connects the piston rod to the body while sealing the upper end of the air sleeve The air sleeve is supported full time by an outer elastomeric sleeve for improved air sleeve operation A jounce bumper mounted internal of the reservoir tube is compressible to resist and cushion jounce strokes of the piston This damper provides optimized vehicle body isolation and damping of both body and wheel axle at their natural frequencies

Self-expansion electrical circuit breaker with variable extinguishing chamber volume

Abstract: A self-expansion electrical circuit breaker includes an arc extinguishing chamber of variable volume by repulsion of a piston by the pressure of the gas in the extinguishing chamber. A semi-stationary contact is securedly united to the piston so as to increase the separation distance of the contacts at the same time as the volume of the extinguishing chamber increases.

Reciprocating pump for an implantable medication dosage device

Abstract: A reciprocating pump suitable for use in an implantable medication dosage device has a piston movable in a chamber connected to a medication reservoir, the chamber having an output closable by a check valve. The check valve includes a movable element which is acted upon by a biasing system to urge the moveable element in a direction to close the check valve. The moveable element has a sealing surface against which an end face of the piston presses with tight adjacency as the piston moves to an extreme position during its output stroke.

Limiting circuit breaker

Abstract: The limiting circuit breaker comprises a Thomson effect propelling device for opening of the contacts. The main contact bridge is securedly united to an operating rod surrounded by an annular opening coil of the propelling device. The latter comprises an opening disk which is movable in relation to the rod and an annular piston securedly united to the rod, springs being disposed between the disk and the piston, so as to return the disk to the rest position facing the coil at the end of the opening travel.

Disposable hypodermic syringe

Abstract: Disposable hypodermic syringe comprising a needle (1) which can be retracted and held inside the syringe which moreover comprises a syringe barrel (4, 5) with liquid chamber designed with a piston (14) with a piston rod (7). Opposite the piston (14) the liquid chamber has an entirely or partially yielding end wall (6) with an opening, and the needle (1) is in its end area opposite its point provided with a head (3) which is subjected to the pressure of a spring in the direction toward the yielding wall (6). The piston (14) has a projection with locking means (10) designed to interlock with the opening in the yielding wall (6) when the piston bottoms in that the needle simultaneously snaps into a cavity (9) in the piston through the opening in the yielding wall (6); further usage of the syringe is hereby prevented.

Adjustable shock absorbers

Abstract: An adjustable shock absorber includes a valve in the piston which has a flow path The valve can be adjusted both rotationally and longitudinally to alter different characteristics of the flow path

Compression ratio-changing device for internal combustion engines

Abstract: A compression ratio-changing device for an internal combustion engine includes an oil passageway (8a) formed through a connecting rod (8) of the engine and connected to a hydraulic oil source. A combustion chamber volume-­changing device (3-6) is provided in the piston (2) and operable by means of hydraulic pressure supplied from the hydraulic oil source through the oil passageway for changing the volume of the combustion chamber and hence changing the compression ratio of the engine. A hydraulic pressure control valve (11) is arranged in the connecting rod for controlling the supply of the hydraulic pressure to the combustion chamber volume-­changing device. A driving device (17-22) is provided at a cylinder block (1) of the engine for driving the hydraulic pressure control valve to cause the combustion chamber volume-changing device to change the volume of the combustion chamber.

Variable-cycle reciprocating internal combustion engine

Abstract: An internal combustion engine having a pair of opposed pistons in a block has a piston connected to a respective crankshaft. A gear train synchronizes the speed and relative angular relationship between the crankshafts. A timing actuator, connected to and engaged with either of the crankshafts, permits continuous selective adjustment of the headspace between the pistons by varying parameters such as intake and exhaust port timing and air flow through the cylinder.

Air spring suspension system with dual path isolation

Abstract: A suspension system (1) for a vehicle having a shock absorber strut (2) with a reciprocal piston rod (4) located within a cylinder, and attachments for securing the piston rod and cylinder to spaced parts of the vehicle. An air spring includes a rigid annular canister (20) mounted on the piston rod by a resilient rotatable mount. The canister forms a fluid pressure chamber (27) in conjunction with a flexible diaphragm (35), one end of which is sealingly connected to the cylinder by an annular rigid sleeve (42) which forms an air spring piston. The flexible diaphragm has inner and outer radially spaced portions connected by a rolling portion. A rigid member resembling a cutaway can (55) is mounted on the rigid canister portion (20) of the air spring and extends about a predetermined portion of the outer portion of the flexible diaphragm and restrains outward expansion of said portion. Restriction of the outward expansion of only a portion of the flexible diaphragm exerts a lateral force on the strut to counteract the unbalanced lateral forces acting thereon due to the offcenter mounting of the strut with respect to the point of contact of the vehicle wheel with the pavement. The suspension system furthermore provides dual path isolation for separating the canister from the vehicle by a primary elastomeric isolator ring (24) and from the strut by secondary elastomeric bushings (13, 14) mounted on the strut, which bushings also provide an upper air seal for the fluid pressure chamber.

A fuel injector for an engine

Abstract: A fuel injector comprising a piston (8) actuated by a piezoelectric element (9). A pressure control chamber (15) is formed between the piston (8) and the top face of the needle (3) and connected to a high pressure fuel source via a fuel passage (18) having a restricted flow area. The pressure control chamber (15) is filled with fuel under pressure. The rear face of the piston (8), which is positioned opposite to the pressure control chamber (15), is exposed to a high pressure fuel chamber (27) filled with fuel under pressure. The driving force acting on the piston due to the pressure of fuel in the pressure control chamber (15) is cancelled by the driving force acting on the piston (8) due to the pressure of fuel in the high pressure fuel chamber (27).

Rod string sonic stimulator and method for facilitating the flow from petroleum wells

Abstract: A close fitting piston of a material such as rubber is attached to the end of a rod string such as a sucker rod which is suspended inside a tubing string installed in an oil well. An orbiting mass oscillator is attached to the upper end of the rod string and is operated at a frequency such as to cause resonant standing wave vibration of the rod string. The piston member attached to the bottom end of the rod string is driven by the vibrational energy to in effect form an acoustical piston which is driven by the vibrational energy. This energy is coupled to the surrounding liquid and thence to the surrounding formation to effectively unclog the well and the casing string of contaminants which may be impeding the flow of effluent from the well. The piston means is made long enough so that it operates as an acoustic monopole with both ends of the piston being vibrationally in phase with the vibrational energy traveling in the surrounding liquid medium.

Syringe for injections, especially intravenous made to be used only once, without any possibilityof re-aspiration

Abstract: In a syringe for injections, especially intravenous --being realized so as to be used only once and comprising a body making up the cylinder to which the needle is fitted, a piston sliding in said cylinder and a piston handling member (stem) for recalling the piston during the liquid aspiration phase and for pushing the piston during the injection phase--said piston and said handling member (stem) are engaged with one another in a non-rigid way, in order to neutralize a further aspiration operation after a first phase of piston push has been carried out.

Internal-combustion piston driving apparatus having a decompression channel

Abstract: In an internal-combustion piston driving apparatus comprising a housing, a cylinder cover fixed to the housing, a cylinder slidably provided to the housing, a piston reciprocally slidably provided in the cylinder, a combustion chamber defined by the housing, the cylinder, and the piston, a fuel supplying device for supplying fuel to the combustion chamber, and an ignition control device for producing a high voltage to ignite the fuel supplied to the combustion chamber, piston position detector for detecting a position of the piston is provided at the wall of the cylinder between top dead point and bottom dead point of the piston. Besides, a decompression channel is provided so as to connect the combustion chamber placed upper than the top dead point with atmosphere for exhausting a combusted gas in the combustion chamber when the piston passes the piston position detector. The decompression channel is opened and closed by means of slide of the cylinder. In addition, a suction valve is provided to the cylinder cover to be placed lower than bottom dead point of the piston whereby the piston is returned by means of atmospheric pressure after a power stroke of said piston.

Pressurized cork-removal apparatus for wine bottles and other containers

Abstract: Stopper removal apparatus of the type in which gas under pressure is directed into a container thereby to eject a cork or like stopper The apparatus directs gas from a gas cylinder into a gas reservoir sealed by a piston valve Each gas cylinder has its own seal to prevent gas escaping during storage As a new cylinder is installed and the cylinder seal is broken, the resulting gas from the cylinder forces the piston valve to its sealing position, so no gas escapes The gas pressure provides the sealing force When an actuator moves the piston valve to an open position, gas passes through passages and a hollow needle that penetrates the stopper to exit within the container to eject the stopper A cover assembly completely encloses the needle A disk at one end of the cover retracts as the needle is inserted into the stopper After the stopper is ejected it remains on the needle within the cover Tabs extending through the cover enable the disk to be returned to its original position thereby removing the stopper and enclosing the needle

Adjustable vibration damper

Abstract: Adjustable vibration damper, in particular for motor vehicles, with a cylinder containing a damping fluid, an axially-movable piston rod inserted in the cylinder in a sealed manner, and a damping piston fastened to the piston rod, which piston divides the cylinder into two work chambers, whereby a damping valve with an axially-movable valve body and a valve seat controls the effective cross section of a damping passage. Control of such a vibration damper should guarantee a continuous adjustment capability, a high adjustment speed, a good temperature behavior and reliably reproducible damping force characteristics, as well as the use of a small amount of control energy. For this purpose, starting from its pressurized end surface, the valve body comprises at least one constant throttle hole running toward the opposite rear side, and another throttle hole running from the rear side in the discharge direction of the damping passage is controlled by a continuously adjustable control pin, whereby the rear side of the valve body and the housing guiding the valve body form a control chamber.

Torque transmission device for a four-wheel drive vehicle

Abstract: A torque transmission device is provided wherein a rotary housing is connected to one of front and rear drive shafts which respectively drive front and rear axles of a four-wheel drive vehicle, while a rotary shaft coaxially carried by the rotary housing is connected to the other of the front and rear drive shafts. The housing receives therein a multiple disc clutch device for transmitting rotational power between the housing and the shaft through friction engagement between alternately arranged outer and inner clutch discs which are respectively rotatable bodily with the housing and the shaft. The housing also receives an axially movable piston to press the clutch discs for friction engagement. An end wall of the housing or an end cap secured thereto and a facing end surface of the piston define an axially narrow circuit chamber, within which a rotary with several radially extending blade portions is received to be rotated by the shaft. Several space sections into which the chamber is divided by the rotor blade portions are filled with silicon oil of a high viscosity. When the rotational speed difference occurs between the rotor and the housing, a pressure is generated within each of the space sections thanks to the high viscosity of the silicon oil and is directly applied to the piston, whereby rotational power is transmitted from the housing to the rotary shaft and vice versa.

Pneumatic powered fastener device

Abstract: A fastener driving device of pneumatic type comprises a piston, 20, within a cylinder, 49, and a driver, 21, connected to the piston, 20, and movable through a fastener driving throat, 26, formed by the housing of the device. A chamber, 52, is provided within the housing to function as an air pressure reservoir. First and second valves, 15, provide an appreciably lower pressurized air to the underside of the piston, 20. The valves, 15, are so arranged that when they are in a first position they allow a flow of pressurized air from the reservoir, 18, to the underside of the piston, 20, and after the pressurized air under the piston, 20, increases to a reduced predetermined ratio to that in the reservoir, 18, the valves, 15, shift to a second position blocking the flow. The valves, 15, are capable of shifting to a third position allowing communication of the air pressure under the piston, 20, with atmosphere while continuing to block communication with the reservoir.

Apparatus for hypodermic injection of liquids

Abstract: A device to introduce a liquid into the hypoderma, the device includes a reservoir which receives a gas under pressure, the gas is delivered via a valve to an interacting piston and cylinder. When the gas is delivered to the piston, the piston moves to eject a liquid from a capsule mounted within the device. The liquid contained in the capsule is then ejected through a nozzle located against the skin of the user.

Paint dispersing training grenade

Abstract: A paint dispersing training grenade includes a grenade body having dispersing passages extending between a central bore and an external surface of the grenade body, a plug threadedly received in one end of the bore, a piston resiliently urged by a spring toward the plug, a rupturable colorant containing capsule positioned between the piston and the plug, a separable release lever releasably pivotal on the grenade body and engaged with an abutment disk on a shaft extending from the piston, and an inertial delay mechanism engaged between the grenade body and the piston. The delay mechanism includes pivotable delay levers engaged with the piston at one end and having wheels rollably engaging a surface of the grenade body at another end. When the release lever is separated, movement of the piston by the spring is resisted by startup inertia of the wheels in rotating. When the inertia is overcome, the piston forceably ruptures the capsule and propels the colorant out of the grenade body through the dispersion passages.

Method of and apparatus for injection molding with pressurized-fluid assist

Abstract: An injection molding method and nozzle for use therein wherein first and second variable pressures are applied to a piston of a valve mechanism of the nozzle so that a differential fluid pressure on the piston causes a tip portion of the valve mechanism to alternately open and close. In this way, the tip portion communicates the flow of resin from a nozzle body of the nozzle to an injection aperture of a mold. Differential pressure on the piston prevents a fluid which distributes the molten resin over the interior surfaces of the mold from entering the flow path of the molten resin in the nozzle body. The fluid preferably is a gas, such as nitrogen. Preferably, the piston is mounted for reciprocating movement within the nozzle body and the first pressure is provided by the resin during resin injection and the second pressure is partially applied by the nitrogen gas. Preferably, the valve mechanism includes a counterbalance mechanism which is set to prevent fluid entry into the mold until the tip portion of the valve mechanism is closed. The resulting article is then cooled to a temperature below the softening point of the resin, the pressure is relieved within the article and the mold is opened to remove the article. The nozzle may also be utilized in making structural foam articles from a foamable resin. The pressure within the mold is relieved to permit foaming by the foamable resin after injection of the foamable resin.

Non-reusable syringe

Abstract: A syringe having a cylinder and a piston longitudinally and rotationably movable in the cylinder. First and second sets of one-way ratchet shoulders and ratchet keys are provided between the cylinder and the piston in which the first set of shoulders and key, when engaged, allow movement of the piston in one longitudinal direction but prevent movement in the opposite second direction. The second set of shoulders and key, when engaged, allow movement of the piston in the second direction but prevent movement in the first direction. A rotational control between the piston and the cylinder provides for sequentially disengaging and engaging the first and second sets of ratchet shoulders and keys upon rotation of the piston relative to the cylinder for operating the syringe for a single cycle.

Fluid delivery system with deficit flow compensation

Abstract: Method and apparatus for compensating for the deficiency in fluid flow occurring during the refill and piston chamber pump-up cycle of a single piston fluid pump are disclosed. The period of time during which the outlet valve is closed and no fluid is being delivered to the system is determined and the pump is driven at a speed greater than the normal delivery speed for a period of time such that the quantity of excess fluid delivered approximates the quantity of fluid that would have been delivered during the refill and pump-up period had the pump been delivering fluid at its normal delivery rate.