Abstract: For a coaxial magnetic valve with an inner valve disk which can move in the axial direction, and with an outer valve disk which surrounds the inner valve disk and which can move in the axial direction, wherein these two valve disks are arranged coaxially to each other and each rises from its corresponding valve seat against the action of a closing spring, and with a magnetic drive for activating both valve disks, the magnetic drive includes two independent magnetic loops which are arranged one above the other in the axial direction, each of which has a coil, and they interact with two armatures which are arranged one above the other in the axial direction and which connect to the inner valve disk or to the outer valve disk, wherein the armature of the outer valve disk is penetrated by a connecting rod connecting the inner valve disk to its armature. With this double magnetic valve, each valve disk can be controlled separately.

Abstract: An electromechanical valve control actuator for internal combustion engines, includes an electromagnet with a magnet and a mobile magnetic plate moving into the vicinity of the electromagnet. The magnet is located on a surface of the electromagnet opposite the plate. The actuator includes an E-shaped magnetic circuit, and the magnet is located at the end of a branch of this E-shaped circuit.

Abstract: An electromagnetic valve actuator for internal combustion engines, includes an electromagnet and a mobile magnetic plate intended to come into contact with a part of the electromagnet. At least one stop is located on the electromagnet or on the plate to limit the contact surface between the plate and the electromagnet. The actuator i the electromagnet includes a magnet in its magnetic circuit.

Abstract: A position control actuator system includes a control element and first and second actuators. The first and second actuators are each comprised of magneto-active twinned material. The first actuator is configured to extend and drive the control element in a first direction when the first actuator is subjected to a magnetic field. The second actuator is configured to extend and drive the control element in a second direction when the second actuator is subjected to a magnetic field. A magnetic field source subsystem is configured to extend the first actuator to drive the control element in the first direction, and extend the second actuator to drive the control element in the second direction.

Abstract: A method for controlling a dual coil fuel injector having an opening coil and a closing coil includes issuing an opening coil pulse to the opening coil. The opening coil pulse has an opening coil pulse width (OCPW) and an opening coil turn on time (OCTOT). A closing coil turn on time (CCTOT) is calculated dependent at least in part upon the OCPW. A closing coil pulse is issued to the closing coil at the calculated CCTOT.

Abstract: A fuel injector (1), especially an injector for fuel injection systems of internal combustion engines, includes a first solenoid coil (5), which cooperates with the first armature (9), a valve needle (13) in a force-locking connection with the first armature (9) for actuating a valve-closure member (14), which together with a valve seat surface (15) forms a sealing seat, and a second solenoid coil (6). In this context, the first armature (9) is acted upon in a closing direction by a first resetting spring (11). A second armature (10) cooperates with the second solenoid coil (6) such that, when the first solenoid coil (5) and the second solenoid coil (6) are supplied with current, a limit stop body (18) that is connected with the valve needle (13) strikes against the second armature (10).

Abstract: An electromagnetic actuator includes two electromagnets arranged opposite one another, an armature movable back and forth between the electromagnets against the force of two mutually counteracting springs, and an adjusting device for adjusting the armature rest position. After several hours of operation, due to settling of components, the pre-tension of the springs changes. To counteract that and achieve a durable adjustment of the pre-tension, the actuator is pre-settled before being placed in service. In this regard, the springs are compressed in repeating compression cycles so often until the energy respectively stored therein due to their compression no longer or only insignificantly differs from the energy stored in the respective spring in a preceding compression cycle, and thereafter the pre-tension of the springs is adjusted. The electromagnetic actuator is useful for controlling the gas exchange in an internal combustion engine.

Abstract: A combined piezo and solenoid actuator are on separate electrical circuits that are coupled via a transformer. The solenoid actuator includes a first set of electrical windings that are arranged as a transformer with a second set of electrical windings that are a portion of a piezo actuator. Current supplied to the solenoid causes a brief induced voltage in the piezo circuitry that causes the piezo stack to expand and push the actuator member with a relatively large force over a short distance. As the magnetic flux of the solenoid continues to build, it applies an electromagnetic force to the armature to push the actuator member through a second larger distance. The combined piezo solenoid actuator finds potential application in valves that require high initial opening forces but also travel distances much larger than that practical with a piezo acting alone.

Abstract: A fluid pressure operating apparatus, comprising: a fluid pressure cylinder for opening and/or closing a contact; control valves for use of open operation and/or closed-circuit, for bringing the fluid pressure cylinders into an opened-circuit operation and a closed-circuit operation; and solenoids, each being provided in each of those control valves. Each of those solenoids has a plunger therein. An operation initiating time of the control valves for use of open (operation) differs from that of the control valves for use of close (operation), when operating to open circuit and when operating to close circuit.

Abstract: An electromechanical valve including an energy absorption system to reduce or eliminate the force with which the armature contacts an electromagnet pole face. The energy absorption system absorbs kinetic energy from the armature assembly prior to the armature plate contacting the electromagnetic pole face to reduce the velocity or impact force of the armature plate against the electromagnet, thereby reducing noise, vibration, and harshness concerns associated with many electromechanical valve actuators. The cooperative nature of the energy absorption system allows damping even during short cycle times by the armature assembly.

Abstract: For a coaxial magnetic valve (1) with an inner valve disk (5) which can move in the axial direction, and with an outer valve disk (6) which surrounds the inner valve disk (5) and which can move in the axial direction, wherein these two valve disks are arranged coaxially to each other and each rises from its corresponding valve seat (9, 10) against the action of a closing spring (7, 8), and with a magnetic drive for activating both valve disks (5, 6), the magnetic drive includes two independent magnetic loops which are arranged one above the other in the axial direction, each of which has a coil (11, 12), and they interact with two armatures (13, 14) which are arranged one above the other in the axial direction and which connect to the inner valve disk (5) or to the outer valve disk (6), wherein the armature (14) of the outer valve disk (6) is penetrated by a connecting rod (15) connecting the inner valve disk (5) to its armature (13).

Abstract: Disclosed herein is an electromagnetic apparatus for automatically and selectively supplying and shutting off fluid. The electromagnetic apparatus includes a frame unit, a through unit, a coil unit, a rotor, a casing, a shaft and a casing. The frame unit is coaxially contained in the piping or a housing forming the flow path of a fluid. The through unit has one or more through holes to form one or more flow paths through the frame unit. The coil unit is placed in the frame unit to generate an electromagnetic force. The rotor is placed to face the frame unit to selectively open and close the flow paths through interaction with the electromagnetic force generated in the coil unit. The shaft supports the rotor, and a casing supports the frame unit and forms the appearance of the apparatus.

Abstract: An actuating device for hydraulically securing a camshaft of an engine of a motor vehicle in a start position has a solenoid valve controlling the flow of a pressure medium to a camshaft adjuster with a rotary slide valve that is fixedly connected to the camshaft and moves the camshaft into the required start position according to the pressure medium supplied to it by the solenoid valve.

Abstract: A dual-coil outwardly-opening fuel injector including a fuel tube connected at a lower end to a lower injector housing. Within the fuel tube are a lower (opening) solenoid pole piece, a specially-formed armature, and an upper (closing) solenoid pole piece. A seat assembly including an injector nozzle, swirler, and valve seat are adjustably threaded into the lower housing. A pintle assembly, including a solid pintle portion supporting a valve head and a tubular portion welded thereto, is axially disposed within the fuel tube and is welded to the armature which is spaced from the lower pole piece by a distance equal to the opening stroke of the valve. A return spring adjustment mechanism disposed on the upper pole piece engages the upper end of the pintle assembly for varying the closing force of the return spring. Opening and closing solenoid preassemblies are mounted external to the fuel tube for magnetically engaging the pole pieces and armature within in known fashion.

Abstract: A system and method for state space control of solenoids, particularly engine valve solenoids with two latching positions. A collection of trajectories are computed or measured, having low-impact landings with latching from different initial energies. The trajectories define flux linkage and electric current functions of the two variables, position and velocity. These tracking functions define future projections based on present inputs. In operation, the controller monitors position, velocity, flux linkage, and current, uses the functions to compute future current and flux linkage, and adjusts the drive voltage to hit the future flux linkage target, causing the system to track a precomputed trajectory to successful landing. An array of tracking functions incorporates varying valve flow influences and corrective actuation. Drift from a precomputed trajectory indicates an unanticipated valve flow influence and a new tracking function selection, leading to course corrections anticipating flow influences.

Abstract: An electromagnetic valve controller estimates a dead time based on predetermined parameters. A dead time for the current cycle is determined based on the estimated dead time. The controller measures a dead time in the previous cycle. The controller determines a deviation between the dead time measured in the previous cycle and the dead time estimated in the previous cycle. The deviation is added to the dead time estimated in the current cycle to determine the dead time for the current cycle. The controller further determines a target de-energization timing indicating when to execute a valve timing command. The dead time determined for the current cycle is offset or subtracted from the target de-energization timing to determine an actual de-energization timing. An electromagnet of the valve is de-energized in accordance with the actual de-energization timing.

Abstract: In an alternate energization process for alternately energizing a valve closing electromagnet and a valve opening electromagnet periodically, one of the valve opening electromagnet and the valve closing electromagnet is de-energized and thereafter the other electromagnet is de-energized at a time delayed by a predetermined time Toff. The alternate energization process is finished when the displaced position of a valve head which is detected by a displacement sensor has reached a predetermined position Vinit while the valve opening electromagnet is being energized. Thereafter, the valve opening electromagnet is continuously energized to seat the valve head in a closed position (initial position) from the time when the displaced position of the valve head has reached a predetermined position Vstart.

Abstract: A canister purge valve for use in an evaporative emission control system. The valve includes a housing having an inlet port and an outlet port. The housing further includes a guide element having a bobbin section. A valve shaft is slidably mounted to the guide element, wherein the valve shaft includes a permanent magnet and a valve element. The valve element is movable between a closed position wherein the inlet port is closed and an open position wherein the inlet port is opened. A pick coil is formed on the bobbin adjacent the magnet. The pick coil generates a first magnetic field having a polarity that is oriented to cause a magnetic attraction with the magnet to move the magnet and thus the valve element to the open position. In addition, a release coil is formed on the bobbin adjacent to the magnet, wherein the release coil generates a second magnetic field having a polarity that is oriented to cause the magnet to be repelled to move the magnet and thus the valve element to the closed position.

Abstract: The invention provides an electromagnetic actuator comprising at least two coils (5, 6) associated with ferromagnetic cores (11) and disposed facing each other, and a moving element (1) extending between the coils (5, 6) and associated with an actuator rod (2), the coils (5, 6) comprising conductors (7) with ends (16) extending transversely to an axis (100) of the coils (5, 6) and fixed directly to pins (21) carried by a connection plate (18) fixed on one side (7) of the coils (5, 6) and including a connection circuit (24) providing connections with a connector (25) also carried by the connection plate (18).

Abstract: An engine is provided comprising an engine housing defining at housing and has a different portion associated with each engine cylinder. Each different portion of the engine auxiliary system has a first electrical actuator coupled to a first valve and a second electrical actuator coupled to a second valve which are wired in series. For example, a fuel injection system is provided with a first electrical actuator operably coupled to a fuel pressurizer and a second electrical actuator operably coupled to a direct control needle valve. The electrical actuators are wired in series on an electrical circuit. A method of controlling a portion of the engine auxiliary system is also provided which consists of actuating a first electrical actuator with a relatively low current and actuating a second electrical actuator with a relatively high current.

Abstract: A dual solenoid latching actuator is disclosed and provides an electrical circuit that includes at least one current restrictor, which are preferably a first diode and a second diode. The at least one current restrictor is positioned and arranged such that current flowing in a first direction can energize only one of a first solenoid coil and a second solenoid coil and current flowing in a second direction can energize only the other solenoid coil.

Abstract: A method for controlling movement of an armature for an electromagnetic valve actuator. The armature moves between pole faces of juxtaposed solenoid coils. Voltage applied to armature capturing coil is varied in a closed-loop fashion as the armature moves through a flux initialization phase, followed by an armature landing phase whereby a soft landing of the armature is achieved during valve opening movement and valve closing movement.

Abstract: The displacement sensor includes a ferromagnetic member for forming a magnetic path, a coil for generating a magnetic field in the magnetic path when feeding a high-frequency current thereto, and a low-resistance magnetic-shielding member that moves across magnetic flux passing through the magnetic path, which is excellent in production, robust, and adaptable for the high speed operation of devices as well.

Abstract: A hydraulic damper for an automotive engine electromechanical cylinder valve 20 is provided. The hydraulic damper includes an inner piston 130 which is slidably mounted within an outer piston 110. The outer piston is slidably mounted within an interior hydraulic filled cavity 82 of a damper body 80. Movement of the valve body 20 along extreme positions causes the inner piston 130 to move the outer piston 110 within the interior cavity 82 to effectuate hydraulic damping of the valve body 20.

Abstract: When an inlet valve is opened or closed via a first mover, by the operation of a first linear actuator, energy accumulated by a first spring or a second spring is discharged by the operation of a second linear actuator, to transmit the energy to the inlet valve via a second mover and the first mover. As a result, the inlet valve can be opened or closed at a high speed, with higher energy efficiency and has an improved durability.

Abstract: A control valve for a fuel injector generally includes a valve body and a spool positioned within a bore of said valve body. The spool is slideable between a first and second position. The control valve also comprises a first bore in fluid communication with a rail inlet of the fuel injector, a cross bore positioned within the valve body and offset from the first bore, and a groove located about the spool. The groove provides fluid communication between the cross bore and the first bore when the spool is in the first position, and seals fluid communication when the spool is in the second position. At least two solenoids are provided on opposing sides of the spool for moving the spool between the first and second positions, and a non-magnetic barrier is provided between the solenoids and the spool.

Abstract: An electromagnetic injector for controlling a fuel quantity to be fed into an internal combustion engine includes a valve body displaceable by an electromagnetic coil system, the valve body acting together with a magnet armature of the electromagnetic coil system. The electromagnetic coil system includes at least two concentrically positioned coils integrated into the magnetic circuit so that in each case a first pole body is positioned between two adjacent coils, and the inner and outer coil are respectively adjacent to a second pole body, the first and second pole bodies are components of the magnetic circuit of the electromagnetic coil system, and in each case adjacent coils may have a common field current flowing through them in opposite directional sense to each other.

Abstract: A valve for mounting in an intake port of a reciprocating engine upstream from a charge changing valve, which valve contains a valve element (46) operating in conjunction with the inner wall of the intake port (16), may be moved back and forth between a closed position and an open position and when in the closed position blocks passage of fluid through the port and when in the open position clears such passage, and is characterized in that the inner wall of the port (16; 70) and the valve element (46) are of a design such that when the valve element is moved from its closed position the opening cross-section initially does not increase at all or increases only slowly and then increases rapidly and when the valve element is moved from its open position the opening cross-section initially does not decrease at all or decreases only slowly and then decreases rapidly.

Abstract: A solenoid operated valve has a valve body with a plurality of ports and a spool slidable within the body to interconnect the ports in different combinations. A solenoid, which is coupled to drive the spool, has a coil wound on an annular bobbin with a tube of an electrically conductive, non-magnetic metal within the bobbin. A first pole piece extends into one end of the tube and a second pole piece extends into another end of the tube. A separate bushing is located in an aperture in each pole piece. Each bushing has a tubular body with a first end section that has a larger outer diameter than a second end section and the second end section that has a smaller inner diameter than the first end section. The solenoid further includes an armature that is slidably received in the bushings and engaging the spool.

Abstract: An electromagnetic fuel injector is provided with a first coil having a large rate of change in time of magnetomotive force and a second coil having a smaller rate of change in time of magnetomotive force than the first coil. During a valve opening operation at the time of opening the valve, current is passed through at least the first coil, and then current of a smaller current value than in the opening operation is caused to flow so as to hold the valve open, using the first and second coils.

Abstract: A fuel pressure regulator is provided for producing more than one fuel pressure. The fuel pressure regulator includes a pressure plate that restricts fuel flow between an input line and an output line. A spring is provided for applying a force to the pressure plate. A coil and armature are also provided. The coil attracts the armature to a casing or head pole, thus applying more force to the pressure plate.

Abstract: An electronic throttle control system having a housing and cover member with a throttle valve, gear mechanism, motor, and failsafe or default mechanism. A spring member positioned between the housing and sector gear member which is attached to the throttle valve shaft, biases the throttle valve plate member toward the closed position. A spring-biased plunger member biases the throttle plate member from its closed position to a default or “limp-home” position. In order to reduce contact between the spring member of the default mechanism and the plunger member, the spring member can have an hourglass shape and/or the outer surface of the plunger member can be minimized.

Abstract: A method and apparatus for detecting a valve position includes the step of providing a non-actuating alternating current signal (24) to a drive coil signal (22). As a valve plunger (14) moves within the coil, the non-actuating signal changes. By monitoring (26,29) the non-actuating signal a control can predict when the plunger reaches a particular position. This invention thus provides a simplified way of detecting an end of travel position (FIG. 1).

Abstract: A solenoid-operated valve which has, between a moving element operated by an electromagnetic force and a valve element, a displacement converting mechanism for increasing or decreasing a displaced amount of the valve element relative to a displaced amount of the moving element, or a force converting mechanism for increasing or decreasing a driving force of the valve element relative to a driving force of the moving element. This solenoid-operated valve can reduce power consumption because it changes the displaced amount or the driving force of the valve element with a simple structure.

Abstract: The invention concerns a device for controlling a fluid flow, characterised in that said device comprises second valve arrangement means interposed in the circuit in series with first valve arrangement means (20, 22, 34), and wherein a second mobile closure element (38) moves between a pressing position, wherein it is pressed on the seat (32) of a second threshold (30) and an opening position wherein the second closure element (38) is spaced apart from the second seat (32) to allow the fluid through the second threshold (30), and in pressing position, the second closure element (38) allows a reduced flow of the fluid through the second threshold (30).

Abstract: A valve assembly includes a valve housing, an engine valve having a valve stem, an armature, and two solenoids. The valve housing has a first end and an opposing second end. The valve stem is located within the valve housing. The engine valve is moveable between an open position and a closed position. The armature is coupled to the valve stem. The armature is moveable between a first and second positions. The first solenoid is adjacent the first end of the valve housing and is operable to move the armature to the first position and the engine valve to the closed position in response to a first digital pulse. The second solenoid is adjacent the second end of the valve housing and is operable to move the armature to the second position and the engine valve to the open position in response to a second digital pulse.

Abstract: An electromagnetic actuator 10 for opening and closing a cylinder valve 14. The actuator includes an opening coil 20, a closing coil 22, a magnetic armature 26 which is disposed between coils 20, 22 and which is fixedly attached to the stem or shaft portion 28 of valve 14, a pair of conventional valve springs 30, 32, and a pair of pneumatic dampers or air cushioning assemblies 34, 36. Pneumatic dampers 34, 36 are effective to selectively decelerate the moving components of the actuator as they approach their respective seats during valve opening and valve closing events, thereby substantially reducing noise and vibration harshness (“NVH”).

Abstract: An engine valve (6) such as an intake valve or exhaust valve is driven to open or close a corresponding intake or exhaust port by attracting an armature (1) onto one of first and second electromagnets (2, 3) and a position of the armature, viz., the position of the engine valve is measured by a permanent magnet (7) and a Hall effect device (8). An adhesive layer (9) whose hardness is lower than the drive axle (5) is used to attach the permanent magnet (7) onto the drive axle (5).

Abstract: A directional valve for respiratory devices has a valve body and a valve seat whose contact surface with the valve body is primarily horizontal. In order to enhance and reinforce the directional valve's operation, the valve body contains a ferromagnetic material, preferably permanently magnetized, a coil is magnetically couplable to the valve body, a source of current is connected to the coil, and a control unit controls the source of current in order to regulate current through the coil to magnetically couple the coil to the valve body, in one or both of the closing and opening directions.

Abstract: The multiple actuator for an electromechanically actuated valve has a housing and a plurality of armature shafts extending through the housing. Each of the armature shafts carry an armature, and two electromagnets which both lie inside the housing. Two springs act on each armature, forcing it into a position of repose between the electromagnets. This configuration makes optimum use of the available basic area above a valve which is to be driven. The armature has a maximum surface area, and optimum dissipation of heat through thermal conduction is possible via the corresponding housing underside.

Abstract: A dual solenoid latching actuator is disclosed and provides an electrical circuit that includes at least one current restrictor, which are preferably a first diode and a second diode. The at least one current restrictor is positioned and arranged such that current flowing in a first direction can energize only one of a first solenoid coil and a second solenoid coil and current flowing in a second direction can energize only the other solenoid coil.

Abstract: A device for operating a gas shuttle valve through an electromagnetic actuator secured and mounted in a component which has an opening and a closing magnet with an axially displaceable armature between the opening and closing magnet. The armature acts through the use of an armature plunger in conjunction with a spring system on a valve stem. A play-compensation element is arranged between the armature plunger and the valve stem.

Abstract: The invention provides an electromagnetic driving valve of an internal combustion engine provided with a significantly compact shock absorbing means which can reduce an impact sound and a vibration in a contact portion between a first transmission shaft and a second transmission shaft and reduce an impact sound and a vibration generated at a time when a valve portion sits on an intake and exhaust port at a time of closing a valve. A shock absorbing means (27) is provided between a first transmission shaft (14a) extended upward from a valve portion (3) and a second transmission shaft (14b) extended on the same axis thereof and supporting a movable plate (7) between a pair of electromagnets (5, 6).

Abstract: An electromagnetic actuator 10 for opening and closing a cylinder valve 14. The actuator includes an opening coil 20, a closing coil 22, a magnetic armature 26 which is disposed between coils 20, 22 and which is fixedly attached to the stem or shaft portion 28 of valve 14, a pair of conventional valve springs 30, 32, and a pair of pneumatic dampers or air cushioning assemblies 34, 36. Pneumatic dampers 34, 36 are effective to selectively decelerate the moving components of the actuator as they approach their respective seats during valve opening and valve closing events, thereby substantially reducing noise and vibration harshness (“NVH”).

Abstract: In a hydraulic or pneumatic flow-control valve, the valve stem itself is made a part of a solenoid arrangement that effects its reciprocation. The valve stem is magnetically responsive (e.g., magnetically permeable or ferromagnetic), and a magnetic field is applied to the stem to cause it to move within the bore of the valve housing; there is no external element required to urge the valve stem into movement. The valve stem is typically sealed permanently within the bore.

Abstract: A method for the control of an electromagnetic actuator coupled to a respective valve and provided with a moving ferromagnetic member connected to at least one point of the valve, a pair of electromagnets disposed on opposite sides with respect to the moving ferromagnetic member and an elastic member adapted to maintain the valve in a rest position. The method comprises the stages of detecting an actual position and an actual velocity of the valve, determining a reference position and a reference velocity of the valve and minimising differences between the reference position and the actual position and between the reference velocity and the actual velocity of the valve by means of a feedback control action.

Abstract: An electromagnetic fuel injection valve in an engine injects fuel by opening/closing a fuel flowing path with a valve element. A controller controls opening/closing of the fuel flowing path and changes magnetic force generated by a control coil driving the valve element so that the magnetic force is less during a valve open state-holding period than at an initial valve-opening time. The controller detects the voltage of a battery and applies the voltage fed from the battery to the control coil, while changing a time interval (Tc), for which current is passed through the control coil, based on the detected voltage, in order to change the magnetic force, without raising the voltage from the battery. The controller also detects increase/decrease of a pressing force on the valve element caused by fuel pressure and changes the time interval (Tc) accordingly.

Abstract: A solenoid valve includes an armature having two permanent magnets axially spaced apart with a steel spacer therebetween. The permanent magnets act as magnetic flux diodes to reduce or prevent undesired forces on the armature due to parasitic magnetic flux. The magnets have stepped outer ends which, in conjunction with pole pieces having corresponding stepped pole piece ends, concentrate magnetic flux to increase the magnetic force on the armature.

Abstract: A method for operating a piston-type internal-combustion engine having electromagnetic valve trains for actuating the cylinder valves, which respectively have an armature that can move back and forth between two electromagnets, counter to the force of restoring springs, with the valves being completely variably actuated by an electronic engine timing control unit. The functioning of the electromagnetic valve trains of each cylinder is detected in the engine timing control unit during operation, and when a functional failure of an electromagnetic valve train is detected at a cylinder, the electromagnet of the failed electromagnetic valve train is acted upon with a capturing current, which brings the armature into an end position at an electromagnet, and from this end position, the electromagnetic valve train is actuated for the ongoing work cycle of the cylinder.

Abstract: An electronic throttle control system having a housing and cover member with a throttle valve, gear mechanism, motor, and failsafe or default mechanism. A spring member positioned between the housing and sector gear member which is attached to the throttle valve shaft, biases the throttle valve plate member toward the closed position. A spring-biased plunger member biases the throttle plate member from its closed position to a default or “limp-home” position. In order to reduce contact between the spring member of the default mechanism and the plunger member, the spring member can have an hourglass shape and/or the outer surface of the plunger member can be minimized.