Showing papers on "Piston published in 2001"

Friction-Reducing Surface-Texturing in Reciprocating Automotive Components

Abstract: A model is presented to study the potential use of micro-surface structure in the form of micro pores to improve tribological properties of reciprocating automotive components. The Reynolds equation and the equation of motion are solved simultaneously for a simplified “piston/cylinder” system with surface texturing. The solution provides the time behavior of both the clearance and the friction force between the “piston ring” and “cylinder liner” surfaces. It is shown that surface texturing can efficiently be used to maintain hydrodynamic effects even with nominally parallel surfaces. It is also shown that optimum surface texturing may substantially reduce the friction losses in reciprocating automotive components. Presented at the 56th Annual Meeting Orlando, Florida May 20–24, 2001

Medication delivery device with bended piston rod

Abstract: The invention relates to: A portable medication delivery device (1) comprising a medication cartridge (11) having an outlet (111) and a movable piston (112), and a housing (12) for holding said cartridge, and a flexible piston rod (13) being operable to engage and displace said piston along an axis (113) of said cartridge, and guiding means (14) for bending said piston rod away from said axis, and actuating means (15), and driving means (16, 17) for transferring movement from said actuating means to said piston rod, said driving means including a driving wheel (17) for displacing the piston rod (13), said flexible piston rod comprising regularly spaced first members (330; 331; 332) adapted to mechanically cooperate with corresponding second members (171) on said driving wheel. The object of the present invention is to provide a medication delivery system that combines compactness with an improved accuracy. The problem is solved in that said flexible piston rod (13) exhibits a linear or approximately linear path between said driving wheel (17) and said piston (112). This has the advantage of yielding a compact, low-weight device with an improved dose accuracy. The invention may e.g. be used in injection or infusion devices for a person's self-treatment of a disease such as diabetes.

Variable valve timing control device for internal combustion engine

Abstract: Either of intake and exhaust valves of an internal combustion engine is provided with a variable valve timing device. In a low-speed, low-load range, exhaust valve advanced-closing control is performed to close the exhaust valve at an earlier timing than the top dead center on the intake stroke, thereby trapping residual combustion gases in the cylinder. Furthermore, the cylinder temperature is raised by setting the intake valve opening timing at around the top dead center on the intake stroke or at a later timing thereof to thereby compress by the piston the residual gases in the cylinder during a period from closing the exhaust valve till the top dead center on the intake stroke. Thus it becomes possible to take in the air-fuel mixture into the cylinder at a higher cylinder temperature than the gas temperature of internal EGR caused by conventional valve overlap.

Rotary piston engine

Abstract: An internal combustion engine including a working chamber assembly housing, intake and exhaust ports, a pair of piston assemblies each of which assemblies includes at least one pair of diametrically opposed pistons within the working chamber assembly housing rotatable about a rotational axis of said piston assemblies, means for interconnecting said first and second piston assemblies for variable speed rotation in the same direction during recurrent periods of rotation, wherein the piston having a piston head and a piston vessel, the piston head of one piston assembly received by the piston vessel of the other piton assembly to form a working chamber. The connecting means includes a pair of internal gears, a plurality of planetary gears and means for transmitting variable speed rotation, a main transmission gear set, and a pair of auxiliary means that is connected to the piston assemblies.

Medication delivery device with telescopic piston rod

Abstract: A medication delivery device comprising a container containing a fluid medicament. The medicament is expelled from the container by moving forward an elastomeric piston inside the cartridge. The piston is moved forward by a telescopic piston rod, which can either be centrally located in the container or eccentric located. One end of the telescopic piston rod abuts the elastomeric piston either by itself or through an additional plate. The abutment having a friction large enough to prevent a lower part of the telescopic rod from rotating. In order to prevent the elastomeric piston from rotating inside the container a second telescopic piston rod is provided parallel with the first telescopic piston rod.

A drug delivery device provided with a one-way mechanism

Abstract: A drug delivery device comprising a housing (1) with a drug container (2) being provided with delivering means comprising a piston (5) for expelling a drug (4) from the drug container (2). The housing (1) further comprising a displaceable piston rod (6) abutting the piston (5) of the drug container (2) and rotating means being in engagement with the piston rod (6), said rotating means being provided with a one-way mechanism. The one-way mechanism comprises a helical spring (12) wound tightly around an axle (11), one end of said helical spring (12) being fixed in relation to the housing (1), the other end of the helical spring (12) being in a free state.

Device for aspirating and dispensing liquid samples

Abstract: A device for aspirating and dispensing liquid samples comprising a pump that comprises a cylindrical chamber, a piston movable in this cylindrical chamber, and a piston drive that engages the piston. The device further comprises a tip connected to the cylindrical chamber with a line, and a channel system that discharges into the cylindrical chamber for flushing or rinsing the latter. The device is characterized in that the piston entirely seals this cylindrical chamber from the channel system, if the piston is positioned in the cylindrical chamber in such a way that a free piston end comes to rest between the channel system and the line. Preferably, the cylindrical chamber is located in a cylinder block, which comprises two parts that are separated by and enclosing an intermediate channel system. The channel system most preferably is implemented as a coherent cavity. According to a first embodiment, the cylindrical chamber is implemented as a sleeve that is inserted in a boring located in a cylinder block. According to a second embodiment, the cylindrical chamber is implemented as a boring located in a cylinder block. Furthermore, the invention also concerns systems with, for example, 384 or more such devices that are arranged in an array.

Homogenous charge compression ignition and barrel engines

Abstract: A homogenous charge compression ignition barrel engine includes an engine housing with a first and second end. An elongated power shaft is longitudinally disposed in the engine housing and defines a longitudinal axis of the engine. A plurality of cylinders surround the longitudinal axis with each cylinder having a closed end and an open end. Each cylinder has a central axis. The open ends of the cylinders are each generally directed toward the first end of the housing. An intake system is operable to introduce a combustible mixture of air and fuel into each of the cylinders. A track is disposed between the first end of the housing and the open ends of the cylinders such that a portion of the track is disposed generally in alignment with the central axis of each of the cylinders. The track has a cam surface that longitudinally undulates with respect to the open ends of the cylinders. A portion of the cam surface is disposed generally in alignment with the central axis of each of the cylinders. The track and the cylinders are rotatable with respect to each other such that the undulating cam surface moves with respect to the open ends of the cylinders. A piston is moveably disposed in each of the cylinders such that a combustion chamber is defined between the piston and the closed end of the cylinder. Each piston is in mechanical communication with the cam surface of the track such that as the cylinders and the track move with respect to each other, the pistons reciprocate within the cylinders. Each cylinder is operable to compress a combustible mixture until the mixture auto ignites, without the introduction of a spark.

The Effect of Piston Topland Geometry on Emissions of Unburned Hydrocarbons from a Homogeneous Charge Compression Ignition (HCCI) Engine

Abstract: The Effect of Topland Geometry on Emissions of Unburned Hydrocarbons from a Homogeneous Charge Compression Ignition (HCCI) Engine

Modular stamped parts transfer gripper

Abstract: A modular gripper assembly having body with a yoke structure (44) defined at one end thereof and an actuator at an opposite end for reciprocally driving a piston assembly (58) within the yoke structure (44) A pair of opposable jaw members (49) having through-slots (48) formed therein are provided within the yoke structure (44) and coupled to the piston assembly (58) by a cam pin (47) so that at least one of the opposable jaw members (49) pivots when the piston assembly (58) moves within the yoke structure (44) The jaw members (49) are removable and interchangeable

Position-sensitive shock absorber

Abstract: The present invention is directed to shock absorbers, including position-sensitive shock absorbers ( 2 ) in which the position-sensitive damping can be different during compression and rebound strokes, and shock absorbers ( 60 ) with damping adjusters ( 80, 118 ) which vary the damping provided during compression and rebound strokes. The position-sensitive shock absorber includes a cylinder ( 4 ) within which a piston ( 122 ) is movably mounted for movement between the first and second ends of the cylinder. Bypass openings ( 24-32 ) open into the cylinder interior ( 6 ) at axially spaced-apart positions. The bypass openings are coupled by a bypass channel ( 38 ). A flow valve ( 40, 42 ) may be positioned along the bypass channel permitting fluid flow from the first opening to the second opening and restricting fluid flow from the second opening to the first opening. A pressurized gas container ( 18 ) may be fluidly coupled to the cylinder interior with a movable barrier ( 14 ) separating the pressurized gas container and the cylinder interior.

Method and apparatus for improved vibration isolation

Abstract: A vibration isolator is disclosed having a housing which defines a fluid chamber. A piston, which is movable to and from a down position, is disposed within the housing. A vibration isolation fluid is disposed within the fluid chamber. A passage having a predetermined diameter extends through the piston to permit the vibration isolation fluid to flow from one fluid chamber to the other. An elastic element is provided for reducing transmission of vibrations from the piston to the housing when the piston is at the down position.

Automatic injection device

Abstract: An automatic injection device has piston holders holding cylinder pistons and plural systems of heads having a drive mechanism for moving the piston holders forward and backward so that the device can hold a plurality of syringes and operates injection or suction in each syringe independently. This device also has a mechanism for prohibiting the backward-moving of the piston holder of a second head when the piston holder of a first head is in a forward-moving state and the piston holder of the second head is in a stopped state. This structure effectively prevents liquid from being undesirably mixed and the injection amount thereof from becoming less accurate.

Method and device for pre-filling a syringe with a contrast agent

Abstract: A method and device for filling a syringe with a chemical solution such as a contrast agent is disclosed. The device has a cylinder holder, a piston holder, a driving mechanism to move the piston holder relative to the cylinder holder, a keyboard to input test conditions, and a computer. Based on the test conditions, the computer calculates the volume of the chemical solution necessary for a patient. The piston holder is allowed to aspirate the precise volume necessary for the patient from a bottle where the chemical solution is stored. Thus the correct and necessary volume of the chemical solution is transferred from the bottle to the syringe, which minimizes the waste of the chemical solution.

Hand-held tool with electromagnetic hammer mechanism

Abstract: A hand-held tool including an electromagnetic hammer mechanism (1) for applying a percussion movement to a working tool (3) and including at least one stator, at least one coil (4 a), a striking piston formed as a yoke (10) supported in a magnetic flux for a limited displacement along the oscillation axis (A) and having at least one magnetomotive region (11) formed of a soft magnetic ferroelectric material, and at least one magnet (5 a) associated with the stator, magnetizable along the oscillation axis (A), and arranged along and adjacent to at least one segment of the coil (4 a) located at an end of the stator.

Suspension system for motor vehicles

Abstract: A suspension system for motor vehicles with level regulation for adjusting a predetermined height of the vehicle body includes at least one piston-cylinder unit with a work cylinder, a piston rod and a damping piston having damping valves. A pump is connected between an oil reservoir and the piston cylinder unit via corresponding inlet and outlet lines. The pump is driven by a drive unit and the level height is detected by a sensor which acts on the drive unit or on a regulating valve via evaluating electronics.

Damping apparatus for bicycle forks

Abstract: A damping apparatus having a cylinder, a fluid, and a floating piston. The cylinder includes a fluid chamber with the fluid located within the fluid chamber. The floating piston is coupled to the cylinder to carry the fluid in the fluid chamber. The floating piston is movable in response to movement of the fluid when a force is applied to the cylinder.

Hydraulic brake apparatus for a vehicle

Abstract: A vehicle hydraulic brake apparatus includes a hydraulic pressure generator which generates a power pressure irrespective of operation of a brake pedal and a regulation valve which regulates the power pressure to a predetermined pressure corresponding to an operation force of the brake pedal and outputs it to an output chamber. A master cylinder generates a master cylinder pressure in a master cylinder chamber by forward movement of the master cylinder piston and a wheel brake cylinder is operated by the master cylinder pressure to apply braking force to a vehicle wheel. An auxiliary piston is located backward the master cylinder piston to define an auxiliary pressure chamber between the master cylinder piston and the auxiliary piston and to move the master cylinder piston forward by an auxiliary pressure in the auxiliary pressure chamber. A pressure modulating device decreases the predetermined pressure outputted from the output chamber to supply the auxiliary pressure to the auxiliary pressure chamber. A pressure chamber communicates with the output chamber of the regulation valve to bias the auxiliary piston backward by a pressure in the pressure chamber. The auxiliary piston is biased backward by both the auxiliary pressure in the auxiliary pressure chamber and the pressure in the pressure chamber when both of the hydraulic pressure generator and the regulation valve are a normal condition in which the predetermined pressure can be outputted to the output chamber of the regulation valve, and the auxiliary piston is moved forward by the operation force of the brake pedal to move the master cylinder piston forward when at least one of the hydraulic pressure generator and the regulation valve is an abnormal condition in which the predetermined pressure cannot be outputted to the output chamber of the regulation valve.

Thermally applied coating for piston rings, consisting of mechanically alloyed powders

Abstract: The invention relates to a wear-resistant coating used for bearing surfaces and flanks of piston rings in internal combustion engines. The wear-resistant inventive coating is obtained by mechanically alloying powders which form a metallic matrix with hard material dispersoids and lubricant material dispersoids. The coating is then thermally applied to the workpieces, especially by means of high velocity oxygen fuel spraying (HVOF). The workpieces coated are bearing surfaces and parts of flanks pertaining to piston rings in internal combustion engines.

Drive mechanism for an injection device

Abstract: A drive mechanism for an injection device is disclosed in wich piston means 306 are selectively driven to expel medicament from within a medicament cartridge 40. A drive mechanism for controlling the movement of the piston means is described comprising a housing 302, a shuttle 300 located for movement within the housing 302 along a longitudinal axis between a first position and a second position, and drive means to move the shuttle 300 within the housing 302. A gear component 304 is located within the housing 302 for rotation about the longitudinal axis and associated with the piston means 306, movement of the shittle 300 between each of the first and the second positions causing movement of the piston means 306.

Seat restraint tensioner

Abstract: A seat restraint tensioner for a seat restraint system in a vehicle includes a housing for operative connection to vehicle structure and a movable piston disposed in the housing. The seat restraint tensioner also includes a gas generator operatively connected to the housing for expelling a gas to move the piston. The piston includes a passageway extending therethrough to control a rate of stroke of the piston when the gas is generated to apply a force for pulling-down belt webbing of the seat restraint system.

Swimming pool cleaner

Abstract: The invention concerns a swimming pool cleaner utilizing the induced flow to a filter plant pump to cause interrupted movement while cleaning the surface over which it operates. The cleaner incorporates a valve with a hollow domed perforated closure member operating in a body with the valve mounted on a stem carrying a rolling diaphragm or a piston subjected intermittently and automatically to the pressure induced by the filter plant pump.

Power transmitting system for four-wheel drive vehicle

Abstract: A four-wheel drive vehicle having a first hydraulic pump operated in operative association with the rotation of front wheels, and a second hydraulic pump operated in operative association with the rotation of rear wheels, such that a difference in rotational speed is produced between the front and rear wheels, a multi-plate clutch is brought into its engaged state by a hydraulic pressure generated by the hydraulic pumps, whereby the mode of the vehicle is shifted into a four-wheel drive mode A torque cam mechanism is disposed between a clutch piston and clutch plates, so that when the difference in rotational speed is produced between the front and rear wheels, the torque cam mechanism produces an axial thrust force immediately to promptly bring the multi-plate clutch into its engaged state The engagement of the multi-plate clutch is achieved with a sufficient engagement force by the hydraulic pressure thereafter produced by the hydraulic pump

Variable valve timing apparatus

Abstract: Just after the start of an engine at cold start, an overlap in the opening time of an intake valve (7 a) and an exhaust valve (7 b) is controlled to include an intake stroke range, such that liquid fuel in an intake port (11) flows into a cylinder with the downward movement of a piston (16) without being directly exhausted to an exhaust side, so that the fuel can be combusted without fail

Arrangement regulating depth of the puncture, used in the device for puncturing

Abstract: An arrangement for regulating the depth of a puncture including a sleeve, a button placed at one end of the sleeve, a piston with a puncturing tip that is slidably mounted within the sleeve, and a power spring placed between the front of the button and the piston. The other end of the sleeve ( 1 ) includes an adjusting ring ( 3 ), which has two inwardly directed half-ringed, oblique limiting members ( 14, 15 ), which are hit by fin ( 7 ) of the piston during puncturing of skin.

Automatic injection device

Abstract: The invention relates to an automatic injection device, which automatically injects a pre-measured quantity of fluid medicine when a tension spring is released. The tension spring moves the ampoule and the injection needle from a storage position to a deployed position when it is released; the content of the ampoule is thereafter expelled by the tension spring forcing a piston forward inside the ampoule. After the fluid medicine has been injected, torsion stored in the tension spring is released and the injection needle is automatically retracted back to its original storage position.

Method for starting a multi-cylinder internal combustion engine

Abstract: The invention relates to a method for starting a multi-cylinder internal combustion engine (1), especially of a motor vehicle, whereby the position of a piston (2) in a cylinder (3) of the internal combustion engine (1) is determined and fuel is injected into a combustion chamber (4) of the cylinder (3) whose piston (2) is located in a working phase In order to enable a starting of the internal combustion engine (1) without the use of an electric motor-driven starter in a manner that is as reliable as possible, the invention provides that that the intake valves and/or exhaust valves (5) of at least one cylinder (3), whose piston (2) is located beyond an upper dead center (OT), are brought, before the starting process, into a position that corresponds to a working phase

Engine cycle and fuels for same

Abstract: An engine cycle that is carried out in a reciprocating piston/cylinder engine consists of a working stroke in which exothermic decomposition of at least one liquid compound is caused to occur without combustion so as to produce a gaseous product of the composition that drives the piston along the cylinder in one direction and an exhaust stroke in which the products of the decomposition are exhausted from the cylinder upon return movement of the piston.