Abstract: A retroreflective sheet structure (10) comprising a transparent layer (20) having a front light-receiving surface (30) and a rear retroreflecting surface (32). Light incident on the front surface (30) will pass through the layer (20), impinge on the rear retroreflective surface (32) and reflect back out through the front surface (30) in a predetermined direction. An identifying indicia (44) is chosen and then formed on the retroreflecting surface (32). This indicia (44) can be used for identification purposes, even years after an end product incorporating the reflective sheet structure (10) has been out in the field.

Abstract: A plunger for use in manufacturing glass containers comprises a first portion configured for contact with a gob of molten glass, and a second portion. At least the first portion has a metal coating of a self-fluxing Fe-based alloy and with a microhardness between 300 HV0.3 and 900 HV0.3. The Fe-based alloy comprises in wt. %): C, 0.5-2.5; Si, 1.0-4.0; B, 1.5-6.0; Cr, 15.0-30.0; Ni, 0-5.0; Co, 15.0-40.0; W, 1.2-5.0; Mo, 0-5.0; Cu, 0-5.0; P, 0-3.0; and N, 0-1.0. The Fe-based alloy may further comprise metals selected from Al, Mn, Nb, S, Ti, V, Zn And Zr each in an individual amount that ranges from 0.01 wt. % to about 2 wt. %, with the overall content of the additional metals less than 10 wt. %.

Abstract: A glass bottle includes a body having a closed end, a shoulder spaced from the end, a neck extending from the shoulder, and a neck finish at an end of the neck for attachment of a closure, characterized in that the neck finish and at least a portion of the neck adjacent to the neck finish have non-circular internal surfaces.

Abstract: The present invention relates to a system for aligning and positioning a male mechanism—pneumatic or servo-electric—to be used at the blank station side of a section of a hollow glass forming machine. The system comprises a mechanism, comprising at least one plunger or a driving unit driven by a servomotor, a guide flange composed of an internal flange for retaining the mechanism in position, and an external flange. The system further comprises a base plate for supporting the mechanism. The plate is mounted on at least one guide bar, rigidly fixed to the resting face of the external flange and intended to allow the base plate to slide along a sliding direction substantially orthogonal to the plane wherein the external flange lies. The base plate rests on a height adjustment group, suspended to said upper plane and intended to move the plate along the guide.

Abstract: A parison mold assembly for a press-and-blow glassware forming machine includes a neck ring for molding a finish portion of a parison, a parison mold for molding a body portion of the parison, and a plunger for insertion through the neck ring into the parison mold for pressing a hot glass gob against inner surfaces of the neck ring and the parison mold. The plunger has an outer surface of revolution around a central axis, including a first portion disposed within the neck ring when the plunger is fully inserted through the neck ring into the parison mold, a second portion spaced from the first portion, and a transition third portion extending between the first and second portions.

Abstract: A parison mold assembly for a press-and-blow glassware forming machine includes a neck ring for molding a finish portion of a parison, a parison mold for molding a body portion of the parison, and a plunger for insertion through the neck ring into the parison mold for pressing a hot glass gob against inner surfaces of the neck ring and the parison mold. The plunger has an outer surface of revolution around a central axis, including a first portion disposed within the neck ring when the plunger is fully inserted through the neck ring into the parison mold, a second portion spaced from the first portion, and a transition third portion extending between the first and second portions.

Abstract: A device for manufacturing a hollow glass item is provided. The device includes a mold having a cavity with a shape substantially corresponding to the outer shape of the glass item and a punch movable between a passive position outside the cavity and an active position inside the cavity, the punch including a hollow body having at least one raised or hollow pattern on at least one outer surface. A method and a punch are also provided.

Abstract: The invention relates to an installation and a method for producing glass stoppers which are provided with a head portion and are used for sealing wine bottles and sparkling wine bottles. The installation comprises a mold for producing glass stoppers, a feeder system for supplying the mold with molten glass, a multistation press, and a removing and handling system for the finished glass stoppers.

Abstract: A plunger foot assembly includes a preassembled gearbox for mounting on a section box base plate of a glassware forming machine. The preassembled gearbox has an input and an output gear with an internally threaded central opening. A hollow externally threaded shaft is threadably coupled to and extends from the internally threaded opening of the output gear. A plunger support is mounted on the hollow externally threaded shaft such that rotation of the output gear of the gearbox raises and lowers the plunger support. The plunger support has an upper face for mounting at least one plunger with air ports of the plunger opening at the face of the support. The plunger support also has air passages for feeding plunger up, plunger down and plunger cooling air to the air ports of a plunger mounted on the plunger support, and a cooling air exhaust passage for feeding cooling air exhaust from the plunger mounted on the support to the hollow interior of the externally threaded shaft.

Abstract: A pressing plunger mechanism for a glassware forming machine has at least one pressing plunger which in normal operation can be moved axially in a reciprocating manner together with a pressing plunger receiver between an inoperative position and a pressing position. A piston rod of a piston is fastened to each pressing plunger receiver, which piston can be displaced in a cylinder of a pressing plunger holder. The pressing plunger holder can be moved axially in a reciprocating manner by a first drive and is connected in a non-rotatable manner to a threaded spindle. A nut which can be rotationally driven by the first drive is engaged with the threaded spindle and is coupled to a driven shaft of an angular gear. An input shaft of the angular gear can be rotationally driven by an electric servo motor of the first drive.

Abstract: An I.S. Machine is disclosed which includes a structure displaceable from a start location to an end location and a motor for displacing that structure. A control controls the operation of the motor to displace the structure and the speed of displacement can be varied by changing inputs to the control. A fixed period of time from a datum to the ideal time when the structure will be displaced to its end location is set and compared with an actual period and a selected input to the control is provided for changing the speed of the structure to reduce the difference.

Abstract: A plunger for intermittently delivering counterblow air to a gob glass at a formidable temperature in a blank mold of an I.S. glass container forming machine being operated on the blow and blow process. The plunger comprises a fixed annular member with an enlarged recess at an inlet end and a valve seat at an upper end. The plunger has a sliding valve member with an annulus of the annular member, and the valve member has a stem portion and an enlarged valve seat portion at a free end thereof. The plunger further has a collar threadably and adjustably secured to the stem portion of the sliding valve member, and the collar, which is slidable within the recess of the annular member, has a plurality of air flow passages extending therethrough. Pressurized air is intermittently delivered to the recess of the annular member through an inlet line, which as an on/off valve therein.

Abstract: A punch assembly for producing hollow glass articles in a mold has a punch member, which is moved to and from the mold along a straight axis by an electric motor positioned eccentrically with respect to the straight axis and connected to the punch member by a rotary-to-linear motion conversion assembly, and a releasable angular connecting assembly interposed between the motor and the motion conversion assembly.

Abstract: A plunger for use in forming parisons during the manufacture of glass containers having a biased open valve therein.

Abstract: A cartridge assembly for a blow-and-blow parison-forming machine comprises a cylindrical barrel, an annular lower stop having a central opening for accepting a piston rod and having an upwardly opening tapered recess adjacent the central opening, an annular cylinder cap having a central opening for accepting a thimble and plunger and having a downwardly opening tapered recess adjacent the central opening. The lower stop, cylinder cap, and barrel form a unit. An annular floating piston is arranged to reciprocate within the cylindrical barrel. The floating piston has a lower tapered end for at the lowermost position of the floating piston resting in the upwardly opening tapered recess in the lower stop and an upper tapered end for at the uppermost position of the floating piston resting in the downwardly opening tapered recess in the cylinder cap.

Abstract: A cartridge assembly for a blow-and-blow parison-forming machine comprises a cylindrical barrel, an annular lower stop having a central opening for accepting a piston rod and having an upwardly opening tapered recess adjacent the central opening, an annular cylinder cap having a central opening for accepting a thimble and plunger and having a downwardly opening tapered recess adjacent the central opening. The lower stop, cylinder cap, and barrel form a unit. An annular floating piston is arranged to reciprocate within the cylindrical barrel. The floating piston has a lower tapered end for at the lowermost position of the floating piston resting in the upwardly opening tapered recess in the lower stop and an upper tapered end for at the uppermost position of the floating piston resting in the downwardly opening tapered recess in the cylinder cap.

Abstract: A plunger for use in forming parisons during the manufacture of glass containers having a biased open valve therein.

Abstract: A glassware machine having a glassware mold and a movable plunger positioned adjacent to the glassware mold for pressing a glass gob in the glassware mold to form a glassware article. The glassware machine includes an electric motor operatively connected to the plunger to move the plunger with respect to the glassware mold to provide accurate pressing of the glass gob when forming the glassware article.

Abstract: Method and apparatus for pressing a parison. A parison mold is composed of neck tool halves and parison mold halves. A gob of molten glass had first been introduced through an upper loading orifice into a cavity of the parison mold, while a pressing plunger was located in a lower loading position. An assembly consisting of a pressing element, a guide sleeve and a piston-cylinder unit was introduced into the loading orifice. Subsequently the pressing plunger was raised from its loading position into the illustrated upper end operating position until its annular end face had moved into position against a stop surface of the neck tool. Following the preliminary pressing process a neck chamber in the cavity is still free from molten glass. It is only at this point that the pressing element exerts pressure on a base of the parison which is being produced. The molten glass is also pressed into the hitherto still free neck chamber of the cavity.

Abstract: A plunger (10) for intermittently delivery counterblow air to a gob glass at a formable temperature in a blank mold of a I.S. glass container forming machine that is being operated on the blow and blow process. The plunger comprises a fixed annular member (12) with an enlarged recess (12a) at an inlet end and a valve seat (12d) at an upper end. The plunger also has a sliding valve member (14) within an annulus of the annular member (12), and the valve member (14) has a stem portion (14a) and an enlarged valve seat portion (14b) at a free end thereof. The plunger further has a collar (16) threadably and adjustably secured to the stem portion of the sliding valve member, and the collar, which is slidable within the recess of the annular member, has a plurality of air flow passages (16a) extending therethrough. Pressurized air is intermittently delivered to the recess of the annular member (12) through an inlet line (20), which has an on/off valve (22) therein.

Abstract: A plunger mechanism which has a one piece housing into which is inserted the upper sealing member. The upper sealing member is secured to the interior wall of the housing at its desired location.

Abstract: A plunger assembly for use in a glass bottle forming machine permitting quick exchange and self-aligning of a plunger held on a plunger driving piston comprising a plunger having an annular recess, an adapter having a plurality of stepped radial bores extending from a central bore into an annular groove, a plurality of retaining balls, one in each radial bore, a split ring sized to fit in the annular groove and an annular retaining spring for biasing the split ring and retaining balls in the annular groove in the plunger such that the plunger can be snapped into the adapter and held in place during bottle making.

Abstract: A punch assembly for producing hollow glass articles in a mold has a punch member, which is moved to and from the mold along a straight axis by an electric motor positioned eccentrically with respect to the straight axis and connected to the punch member by a rotary-to-linear motion conversion assembly, and a releasable angular connecting assembly interposed between the motor and the motion conversion assembly.

Abstract: A plunger mechanism which has a one piece housing into which is inserted the upper sealing member. The upper sealing member is secured to the interior wall of the housing at its desired location.

Abstract: A fluid administration system for the operation of a cylinder and piston assembly for actuating mechanisms, mainly glassware forming and handling mechanisms, allowing rapid changing thereof, comprising: a passage network practiced at the cylinder cap, connected to the fluid admission and discharging passages of the centering ring, at the cylinder and at the support frame; and speed controlling valves, at the passage network of the cylinder cap, to control the velocity of discharging of fluid from the cylinder and piston assembly in its ascending and descending runs.

Abstract: Plunger mechanism for the pressing of gobs of molten glass in the blank mould of an I.S. machine for the production of hollow ware, characterized in that the driving and controlling of the up and down movements of the pressing plunger is effected by a linear electric motor, conveniently a tubular-type linear motor.

Abstract: A plunger assembly (10) for a glass container forming machine of the I.S. type, the plunger assembly having a plunger (12) that is open it one end and is non-threadably secured at its open end to a free end of an annular cylinder rod (14) that operates to reciprocate the plunger relative to a blank mold of the forming machine. A perforated cooling air inlet tube (20) is positioned within the plunger, and the free end of the air inlet tube is held against a free end of an annular extension (22) of the cylinder rod, an opposed end of which is threadably received in the cylinder rod, by a split locking ring (30) an inwardly facing recess (36, 38) of which traps a radially outwardly extending flange (40) of the plunger to axially position the plunger relative to the split ring. The split ring abuts an endless ring (24) and is axially positioned thereagainst by a flange (44, 46) of the split ring that is received in a recess (42) of the extension.

Abstract: A single drive mechanism for simultaneously driving plungers of a plurality of metal molds in each of the sections by employing an output cost-efficient electric motor as a mechanism for driving the plungers. The novel plunger drive mechanism makes it possible to correctly and efficiently mold the articles without causing defect even when the glass material is fed in varying amounts into the metal molds. In molding a glass material thrown into the metal molds by moving the plungers forward, a mechanism moves the plungers forward with a predetermined torque and then backward. The mechanism includes a drive motor, a main gear, planetary bevel gears, a first driven wheel member, a second driven wheel member, a first drive pinion, a second drive pinion, a first main drive member, and a second main drive member.

Abstract: An I.S. Machine for making glass bottles, having a plurality of sections, each having a blank station for forming a parison. Each section has a section frame having a top surface, and a plunger mechanism including at least one plunger canister having a lower cylinder and an upper flange. A horizontal mounting plate having a top surface and vertical openings for receiving the lower cylinder of each of the plunger canisters is fixedly secured on the top surface of the section frame. The section frame top surface has vertical openings for receiving the lower cylinders of each of the plunger canisters and the flange of the plunger mechanism is secured to the top surface of the mounting plate.

Abstract: A device for inhibiting glass from falling into an annular cavity formed between a plunger piston and an inner piston telescopically journalled within a longitudinal cavity within the plunger piston includes a rigid sleeve mountable to the plunger piston, adjacent walls of the longitudinal cavity, so as to substantially fill the annular cavity. The sleeve is mountable into snug sliding relation with the inner piston.

Abstract: The present invention is directed to an apparatus and method for forming glass article from sheet glass. More specifically the apparatus comprises a mold, a plunger being cooperative alignment with the mold, wherein the mold and the plunger form a cavity exhibiting the shaped of the glass article, an outer trimmer for separating the glass article from the surrounding excess sheet glass, and an inner trimmer for forming the aperture in the glass article, and the method involves forming the aperture during the hot-forming process, therefore eliminating a post-formation step.

Abstract: A hollow glass parison is formed by pressing a gob of molten glass in a mold cavity with a plunger which is moved in a linear direction by a leadscrew which is connected to the plunger and is driven by a servomotor. Actuation of the servomotor creates a rotation of the leadscrew which causes the plunger to advance in a linear direction from a first position until the plunger contacts the gob at a second position. The plunger then advances to press the gob in the mold cavity to form the gob into a parison. During movement of the plunger in the linear direction the position of the plunger is continually sensed with a position-sensing resolver which provides position information to a system controller which utilizes the position information to control the position of the plunger prior to contacting the gob in the mold cavity, the depth of plunger penetration into the gob of molten glass during pressing by controlling the pressing pressure, and the weight of the gob of molten glass.

Abstract: A plunger base module for a selected number of vertically extending cylindrical plunger canisters each having a bottom surface and including a set of service conduits including plunger up, plunger down, and counterblow/vacuum or cooling, with each of the service conduits in a plunger canister having a selectively located inlet port communicating with the bottom surface of the plunger canister. The plunger base module includes a permanent plunger distribution base having a top surface and a plurality of sets of service conduits, each set including plunger up, plunger down, and counterblow/vacuum or cooling. Each plunger distribution base service conduit has an outlet port communicating with the top surface. A removable transition plate has a bottom surface for engaging the top surface of the plunger distribution base and a top surface.

Abstract: A press head drive cylinder control having a force sensing, force signal providing load cell on the drive cylinder of a glass molding press. The glass molding press having a base, a mold table rotatably mounted on the base, a plurality of mold positions on the table for locating from one to a plurality of molds thereon, at least one mold at a mold position, a press head, a press head tower, and a press head drive cylinder supporting the press head and being reciprocally mounted on the press head tower for movement of the press head to and from a mold aligned at a molding station. The press head drive cylinder control responds to force signals from the load cell to control the press head drive cylinder location, movement, and pressing force, during glass molding.

Abstract: A method and apparatus for forming a glass container in a blow-and-blow process. The apparatus includes an air flow controller having a housing defining a chamber, a piston disposed for reciprocal movement from a first position to a second position within the housing for moving a slide block therein, first and second passages extending through the slide block, a first port in the housing in flow communication with the second passage and a transducer when the piston is in its second position to create a negative air flow through the second passage and first port when a pressurized air flow is induced through the transducer to draw a vacuum beneath a gob in a blank mold to form a finish in the gob and sweep debris away from the gob and blank mold, and a second port in communication with the first passage and first port when the piston is in its first position to provide pressurized air to the gob.

Abstract: An I.S. Machine for making glass bottles, having a plurality of sections, each having a blank station for forming a parison. Each section has a section frame having a top surface, and a plunger mechanism including at least one plunger canister having a lower cylinder and an upper flange. A horizontal mounting plate having a top surface and vertical openings for receiving the lower cylinder of each of the plunger canisters is fixedly secured on the top surface of the section frame. The section frame top surface has vertical openings for receiving the lower cylinders of each of the plunger canisters and the flange of the plunger mechanism is secured to the top surface of the mounting plate.

Abstract: A plunger mechanism has a plunger canister module to be mounted on the top wall of a section frame of an I.S. machine. The module includes one, two, three or four plunger canisters each having a vertically extending cylinder having a locating diameter at the top and a mounting flange secured to the top of the vertically extending cylinder. The module also includes a horizontal mounting plate adapted to be mounted on the top wall of the section having a top surface and a number of holes, corresponding to the number of plunger canisters, extending vertically therethrough for matingly receiving the locating diameter of each of the plunger canisters.

Abstract: A plunger mechanism comprising a vertically extending cylindrical plunger canister having a bottom surface and including a plurality of service air conduits with each conduit having an inlet port communicating with the bottom surface. A plunger distribution plate below said plunger canister having a top surface and including a corresponding plurality of service air conduits which are to be connected to the plunger canister service air conduits with each plunger distribution plate conduit having an outlet port communicating with the top surface. At least one outlet port of the plurality of service air conduits in the plunger distribution plate which are to be connected to the plunger canister service air conduits being axially offset from the corresponding inlet port of the plunger canister. A transition plate intermediate the plunger canister and the plunger distribution plate having a bottom surface for engaging the top surface of the plunger distribution plate and a top surface.

Abstract: The present invention is directed to an apparatus for pressing a glass article. The apparatus includes a frame. A mold having first and second mold halves are mounted on the frame. The mold halves define a cavity for receiving a glass gob. The mold halves are movable between open and closed positions. The apparatus includes a device for opening and closing the mold halves. A plunger is movably mounted on the frame adjacent the cavity. The plunger presses the glass gob into the cavity to form the glass article. The apparatus further includes a device for moving the plunger. An alternative embodiment of the invention is directed to a machine for pressing a plurality of glass articles at a high cavity rate. In this embodiment, the machine includes at least two apparatus as described above mounted on a device for moving the apparatus.

Abstract: In the press-molding method for producing molded glass bodies, the molding plug remains in contact with the molded glass body in the mold after the molding process until the regions close to the surface have cooled to a temperature at which the molded body at least temporarily possesses sufficient inherent stability to be removed from the mold. To prevent re-heating of the regions near the surface from causing undesirable deformation of the molded glass body, the body is transferred to a cooling station after being removed from the press mold. With this method, the waiting period during which the molded glass body is in the mold is minimized, so this mold is available for another molding process after a very short time. The capability of a glass-molding apparatus operated according to the method of the invention is thus increased.

Abstract: Controlled movement of the pneumatically operated plunger in the narrow neck press and blow process of manufacture of glass containers is achieved by use of a pressure regulating valve in the air supply to the plunger which determines the pressure supplied according to the magnitude of a control signal which is determined by set point means operating in response to timing pulses from a timing control of the machine.

Abstract: A plunger supporting mechanism includes a bottom mold into which a gob is loaded; a plunger which is arranged above the bottom mold, and which is lowered to pressure the gob in the bottom mold to press the gob into a glass product, the plunger having an upper portion provided with a flange; a floating unit which supports the flange in a floating manner to support the plunger so as to be movable in a horizontal direction; and a press machine for raising and lowering the plunger through the floating unit; wherein the floating unit is supported so as to be tiltable with respect to the press machine, or the plunger is supported so as to be tiltable with respect to the flange.

Abstract: The apparatus comprises at least one plunger (2) and a plunger holder (3) which can be raised and lowered. An arm (18) of a tilt lever (17) is coupled to the plunger holder (3). A link member (22) of a drive system (23) cooperates with the other arm (20) of the tilt lever. The link member (22) is adjustable along said other arm (20) in order to change the stroke of the plunger. The drive system (23) comprises an electric servodrive with a take-off shaft (13), the drive being connected to the link member (22) and being controllable by electronic control means. The link member (22) is arranged on a tie rod (26) which at one free end is coupled (28) to a pivot lever (27) which is mounted fixedly in relation to the apparatus. At a central coupling point (30) of the pivot lever (27) is coupled a push rod (32) whose other end is coupled to a crank (14) of the take-off shaft (13).

Abstract: A plunger for a gob feeder arranged at a forehearth of a glass melting tank furnace which includes a plunger head arranged above an opening of the forehearth, having a hollow space formed therein and, a raising and lowering unit for raising and lowering the plunger head so as to extrude molten glass in the forehearth from the opening when the plunger head is lowered.

Abstract: A self-lubricating ring assembly (10) for use in forming a finish portion (F) of a hollow formable glass parison (P), the neck ring assembly (10) having an opposed pair of part cylindrical metallic neck ring sections (22a, 22b) that can be opened and closed with respect to one another. The opening and closing of the neck ring sections is guided by a guide ring assembly (24) that is made up of a larger diameter flange member (26) and a smaller diameter hub member (28) that is coaxially and removably joined to the flange member (26). A peripheral portion of the flange member (26) is slidably received in a slot that is defined by opposed slot portions (30, 30b) of the neck ring sections (22a, 22b). The flange member (26) of the guide ring assembly (24) is formed of graphite, to eliminate the need for external lubrication of the neck ring assembly (10), and the hub member (28) is formed of a hardened metal alloy.

Abstract: A plunger assembly for a glassware forming machine is readily convertible between, for example, double and triple gob configurations and between press and blow and blow and blow operation. A framework is provided with a replaceable positioning plate with recesses corresponding to the required number of cylinders, and air connections are provided which, when the cylinders are in position, provide the necessary operating air.

Abstract: A plunger mechanism for forming a hollow article of glass in a "narrow neck press and blow" operation which utilizes an electro servo-driven leadscrew to actuate it. A position sensing resolver is used to determine the position of the plunger over the full range of its stroke, and the position information can be used as feedback to control the position of the plunger prior to contacting a molten gob of glass in a mold chamber. The depth of the plunger penetration into the molten gob is then controlled by the pressing pressure, which is a function of motor torque and screw mechanics. It is possible to control the pressure exerted on the molten glass gob by controlling the torque applied by the motor. A separate gob weight controller is not required because changes in gob weight can be determined by closely monitoring the plunger penetration of the gob.

Abstract: A multiple glass feed system for use with a glass forehearth including a plurality of closely spaced plungers, each of which is individually adjusted independently of the other. The upper end of each plunger is oval in cross section and the lower end is round. The oval portions of the plungers are each supported in an individual clamping mechanism having a chuck housing, a curved liner plate within the housing, and a cap screw which extends between the housing and liner plate to engage the upper end of the plunges and clamp the plunger in the housing to arrange the plungers in side by side relation to each other with the long axis of each oval portion parallel to the long axis of the adjacent plungers.

Abstract: A set-up fixture (50) for positioning the needle holders (18, 20, 22) of a molten glass feeder bowl with respect to one another, the fixture having a frame member (52) and a plurality of prongs (54, 56, 58) depending from the fixture, one prong for each of the needle holders of the feeder bowl installation. The prongs are inserted into apertures (24b, 26b, 28b) of base members (24, 26, 28) from which the needle holders are carried to accurately position support arms (30, 32, 34) to which the base members are affixed, and thus the needle holders and the plunger needles (12, 14, 16) carried thereby, with respect to one another. The prongs depend different distances from the frame member to permit sequential insertion of the prongs into the base member apertures.

Abstract: The present invention is directed to a method and an apparatus for forming glass articles from molten glass involving differentially cooling a plunger for press forming glass articles in a cooperative forming mold. More specifically, the method involves introducing cooling fluid into an inlet cooling cavity located in the upper portion of the plunger and causing the cooling fluid to flow from the inlet cooling cavity into a cooling passage located along the periphery of the nose portion and thereafter to flow into a outlet cooling cavity located in the upper portion of the plunger and thereafter exhausting the spent cooling fluid from the plunger.