Abstract: When injection-molding a molten thermoplastic resin into a molding having different thicknesses, a void inducing member is set in a cavity corresponding to heavy sections. Then gas pressure is applied passing through a gas passageway to a tip end of the void inducing member, thus forming a void nucleus in the resin adjacent to the tip end of the void inducing member. The void nucleus develops to a void by shrinking force of the resin as the molten resin cools.

Abstract: A plastic molding apparatus which produces the molded part on a centrally located core with this core being elongated and having a non-linear, longitudinal, center axis. The core is removed from the molded part by being pulled directly from the molded part which causes the molded part to assume a temporarily deformed shape with the molded part then springing back into its molded shape after removal of the core.

Abstract: Disclosed is a molding apparatus which includes(A) a mold for making an undercut part which includes coring sandwiched between top and bottom cavity halves, where the coring is divided into three or four sections; and(B) a press for(1) separating the coring from the top and bottom cavity halves; and(2) separating the sections from each other.

Abstract: A high density mold (8), for molding performs having a high density of very small openings, having: a core pin sub-assembly (10) made from a number of plates (16) having core pins (18) extending outwardly from an edge of each plate; and, a stripper assembly (40) that is composed of a stripper sub-assembly (14), formed by bonding thin sheets (34) with apertures (36) corresponding to the core pins (18), and a support sub-assembly (12), formed by a number of plates (24) with spacers to define spaces (26) for the core pins (18), the stripper sub-assembly (40) slides along the core pins (18) to strip the molded preforms from the core pin sub-assembly (10).

Abstract: Cold-stretchable sheet material is isostatically formed at an operating temperature beneath the softening temperature of the sheet material by means of a fluid pressure medium at a pressure of more than 20 bars so as to produce a deep-drawn formed plastics piece. Forming may take place abruptly. The sheet to be formed may be provided with a coating such as an ink imprint. The resulting thin-walled deep-drawn piece may be backed and reinforced by injecting further plastics material.

Abstract: An injection-molding tool for producing pipe fittings with an internal groove has bead-forming segments of the core alternating with one another on respective bell crank levers at alternating bell-crank levers being fulcrummed at fixed locations on a core sleeve while the other bell-crank levers are fulcrummed on a ring movable axially on the core sleeve. The actuator is a hydraulically or pneumatically moved actuating sleeve having grooves or slits receiving radial arms of the levers with abutments or end surfaces axially staggered so that one group of segments is retracted inwardly and axially first to allow the second group of segments to be swung inwardly.

Abstract: A runner shut-off for an injection molding system press fit into a blind bore formed in one of the mold plates. The bore cuts through one of the runners that supplies material to the mold cavities. The runner shut-off includes a casing and a core pin rotatably received in the casing. The core pin is movable to a number of discrete rotated positions with respect to the casing. Slots are formed in the casing and the core pin to join the runners cut by the bore when the core pin is rotated to a position allowing flow of material.

Abstract: There is provided by the present invention a compression molding tool for producing apertures of a desired configuration in preselected locations in a compression molded article and a method for producing the apertures. The tool has first and second relatively movable tool halves each supporting a mold section. The mold section associated with the second tool half includes a movable portion that is relatively movable with respect to the second tool half. The first tool half is moved relative to the second tool half until the first and second mold sections engage each other to form a mold cavity therebetween. Devices for creating apertures are included on at least one of the mold sections and are extended into appropriately configured receptacles in the other mold section after the mold sections are engaged, but before molding material is forced by compression into the mold cavity.

Abstract: Apparatus for producing plastic parts with a resilient projection, such as connectors for corrugated tubing. The apparatus includes means for flowing plastic material on a core provided with a recess to mould the resilient projection, plural core cam surfaces to extract the resilient projection out of the recess, after the mass of plastic material is solidified and extract the solidified part from the core.

Abstract: A method for manufacturing a drip irrigation emitter, including the steps of molding onto an injection-mold core having at least n different active diameters, n different, axially spaced apart members of the emitter, at least n-1 of the members being substantially annular, the inside diameter of at least one of the annular members being a tight fit on the outside diameter of the next smaller of the members, stripping the members off the core, starting from the member having the largest inside diameter, thereby causing the members to be tightly nested one inside the other, in a predetermined axial and angular relationship, and ejecting the thus fully assembled emitter from the mold. There is also provided an injection mold for producing fully assembled multi-part drip-irrigation emitters.

Abstract: In the case of certain series-produced finished parts, such as switch cross ties, the precision of the assembly of components is of decisive importance. The components should neither be damaged nor should their position be changed during assembly. During the assembly process, they have to be nonslidably fastened in the casing, at the same time the fastening should not damage the finished part or the component during the movements occurring in the hardening process or during the removal of the casing from the finished part. The temporary connection uses a blind rivet which can be introduced and driven in from above with its stem through the bore of the bottom plate carrying the component, as well as through the bore determining the position of the component in the casing plate, and is solidly anchored on the outside of the casing plate by rivet-head-like enlargement.

Abstract: A molding method is used to produce a module cover for an air bag device which has undercut portions in mounting edge portions thereof. A lower mold disposed inside the module cover to be produced is of the split type so that is includes a central mold disposed at the center and a plurality of lateral molds for molding of the undercut portions. The mating face of the central mold with each lateral mold is oblique so that its bottom is closer to the edge of the module cover than its top. Thus, the module cover produced can be detached from the lower mold by moving the lateral molds mutually inward.

Abstract: Apparatus and method for forming a three dimensional injection molded article having a pair of passageways extending therethrough with a locking indentation in each passagway using first and second mold parts each having open ended cavities having an end wall and a plurality of sidewalls formed therein wherein a pair of fixed arms are mounted on the end wall of the first mold part so that they are spaced from each other and each of the sidewalls have portions extending out of the open ended cavity and have contoured surfaces and wherein a pair of movable arms are mounted on the end wall of the second mold part for rotation about fixed axes and are spaced from each other and from each of the sidewalls and wherein each movable arm has a contoured surface adapted to be moved into a continuous contacting relationship with the contoured surface of one of the fixed arms and when in the contacting relationship to provide protruding portions to form said locking indentations.

Abstract: The dimensions of a plastic product are controlled while injection molding the product in a mold cavity of a mold comprising a core section and a cavity section, separated by a parting line and defining the mold cavity.

Abstract: A mold assembly for use in an injection molding process to mold a one-piece article such as a washing machine tub. The mold assembly includes first and second relatively moveable mold plates, a mold core projecting from the first mold plate, and a plurality of mold sidewall assemblies. The mold core includes an annular outer mold surface portion which tapers inwardly to provide draft to ease the removal of the molded article from the mold assembly, and which is provided with a plurality of generally teardrop-shaped projections. Each teardrop-shaped projection converges to its narrowed end in a direction opposite the direction of removal of the article from the mold core and is configured to further ease removal of the article from the mold assembly. The mold assembly also includes a plurality of core pins mounted on the mold sidewall assemblies.

Abstract: In a molded intake manifold/fuel rail, a through-passage for the conveyance of combustion air is created by disposing two separably engaged core parts of the mold to occupy the entirety of the through-passage during the molding process. After molded material has solidified, the core parts are separated in generally opposite, but non-colinear directions. During the molding process, one core part occupies the entire length of the through-passage along a certain circumferential extent of the through-passage while along another circumferential extent, both core parts conjointly occupy the entire length of the through-passage.

Abstract: A tape cassette reel molding apparatus which includes upper and lower opposed molds for forming upper and lower flanges of the tape cassette reel and first and second hub molds provided between the upper and lower molds, the first and second hub molds each having an opposing face which has a semicylindrical cavity therein, at least one of the first and second hub molds being slidable in a direction parallel to the face of the upper mold and away from the other of the first and second hub molds so that when the upper and lower molds and the first and second hub molds are slid into position against each other, the respective cavities therein are all contiguous and a unitary tape cassette reel can be molded.

Abstract: A plastics threaded fitting molding mechanism, which is aimed to resolve the conventional problem limited only to produce single direction threads, utilizes three pushing rods and corresponding co-axially disposed therein, performing reciprocating movement, to make the three ways plastics threaded fitting. Therefore, it is substantial to save time and labor while reducing manufacturing cost.

Abstract: The dimensions of an injected molded hollow plastic product are controlled and the separative force exerted against mold sections during molding of the product are reduced by injecting plastic material continuously from a gate into a mold cavity having flow channels extending through the cavity region until the mold cavity is filled with said injected plastic material, with said injection being under such conditions of injection pressure, injected plastic material temperature, mold cavity temperature, flow channel length, distance between flow channels, flow channel thickness and wall thickness in a thin-cavity region between flow channels that initially injected plastic material solidifies in the thin-cavity regions to thereby stabilize one mold section in relation to the other mold section prior to the mold cavity being filled with the injected plastic material, and to thereby reduce said separative force.

Abstract: The retractable pin for an injection mold machine used for molding golf balls has a frictionless bushing means affixed at its outer end which is slidable along a shaft. The shaft and the frictionless bushing means are coaxial and perpendicular to the retractable pin. The pin head is shaped substantially like a dimple.

Abstract: A process and apparatus for injection molding thin-walled plastic articles having comparatively thick lip portion. The apparatus has a mold cavity and a mold core defining a cavity space in the shape of the article and at least one injection gate adjacent a portion of the cavity space defining the lip portion through which molded plastic is injected into the cavity space. The direct lip gating approaches employed in the apparatus do not sacrifice core/cavity alignment and conventional mold motions along the machine axis and form plastic articles having substantially no gate vestiges on the lip sealing surface or on the outer perimeter of the lip.

Abstract: An internal core lifter in a mold is provided with both linear motion and pivotal seating in a universal coupling that slides linearly along an ejector plate. The pivotal seating allows the core blade to be used at various angles in different molds, thereby reducing the inventory of core blade needed. To resist high forces encountered during ejection and during the opening and closing of the mold, the preferred pivotal seating comprises wide arcuate dovetail surfaces on the lower end of the core blade and on a slidable support which has linear dovetail surfaces with the ejector plate. The upper end of the core blade may be configured to be part of the molding surfaces to mold an undercut in a plastic part. The upper end of the core blade is moved laterally from the undercut and then is shifted upwardly to engage and eject the part.

Abstract: A method and apparatus for molding a product having internal threads includes a threaded mold core and a device for rotating the mold core about the axis of its threads and for axially withdrawing the core from the mold at a rate that is related to the rate of rotation, according to the pitch of the threads. This is accomplished by a cam, which is rotated in synchronism with the device that rotates the core, and a follower for displacing the core as the cam is rotated. The cam follower is fixed with respect to the mold. The cam and threaded core are positioned on a carrier, along with the device for rotating the core, such that rotation of the cam displaces the carrier away from the mold. The core is inserted into the mold, prior to the molding process, by displacing the carrier toward the mold without rotating the core.

Abstract: This disclosure relates to a mold ejecting apparatus for ejecting an inner mold from a cylindrical molding, e.g. a cylindrical rubber molding, sticking to the outer circumference of the inner mold, or for ejecting the cylindrical rubber molding from the inner mold. A plurality of small holes are formed through the circumferential wall of the inner mold, and a pressurized fluid feed line is connected to an opening in one end face of the inner mold to introduce a pressurized fluid into the hollow interior of the inner mold. A plurality of matching members are movable to contact or come close to the outer circumference of the inner mold and match with an end face of the molding, the matching members being movable towards and away from the outer circumference of the inner mold. A pressing apparatus is provided for moving the molding relative to the matching members and the inner mold and separating them.

Abstract: A injection-molded connector for single-mode optical fibers includes two mating plugs having aligned fiber-receiving holes. To keep transmission losses in the connector at an acceptable level, the eccentricity of each hole relative to its plug profile must be maintained within a fraction of a micron. The mold utilized to form the plugs includes a dual-eccentric-cam adjustment mechanism that comprises nested conically shaped cams. In a method for fabricating such plugs, rotation of the cams serves to move a part of the mold that positions a hole-forming pin. By rotating this mechanism, the eccentricity of the fiber hole relative to the profile of the molded plug can be established and maintained within the required precision.

Abstract: A method and apparatus for molding plastic articles in two colors, particularly, the bodies of magnetic tape cassettes, in which a strong bonding force is provided between the two portions without having to form a recess and projection on the joining edges of the two portions. A slide core, which is moved in and out of a primary molding cavity between the molding of the two portions of the article, is provided with a tubular passage having an opening within the primary molding cavity along edge portions of the slide core. The slide core is fully inserted into the primary molding cavity to mold the first portion, then partially withdrawn to form a secondary molding cavity in which the second portion is subsequently molded. After molding the first portion, an adhesive is injected through the tubular passage along the edges of the first portion which will join corresponding edges of the second portion to thereby firmly join the two portions.

Abstract: A molded part formed by outsert-molding a resin into a through hole of a pipe part includes a pipe part and a resin part. The pipe part includes a hole having a tapered surface whose size is gradually reduced inward from an end portion of a through hole formed in an outsert-molded part such as a metal part, and a resin part has an outer shape matching the tapered surface. The resin part is formed in the pipe part by outsert molding.

Abstract: Terminals having rectangular post sections of very small dimension are secured in housing passageways of an electrical connector, which passageways are molded using core pins larger in dimension than said very small dimensioned terminal post sections, so that the oversized core pins are robust and endure repeated molding cycles. End sections of the core pins have the very small dimension of the terminal post sections and the passageways have constricted end sections which precisely locate the terminal post section along the connector mating face. An increased terminal width at the insertion face creates an interference fit within the passageway for retention. The core pin has a strength rib along most of one side and the forward rib end is tapered to the reduced-dimension pin end section which results in a tapered passageway transition surface to eliminate terminal stubbing during insertion.

Abstract: A unitary helical coil spring assembly is inserted in a tubular body to form a neon tube support. The assembly is molded of plastic using a mold comprised of two planar blocks in each of which there are a series of axially spaced apart recesses configured to form half convolutions of a spring and there are projections having rounded ends projecting from between half convolution recesses on each mold block which interdigitate and project into the half convolution recesses in the opposite mold block when the planar surfaces are interfaced so the rounded ends cooperate to form a circular inside diameter of the spring when plastic is injected in the recesses.

Abstract: An injection mold for producing a two-piece golf ball includes first and second cavities having mating hemispherical inner surfaces with retractable pins for supporting a solid core within the cavities spaced from the inner hemispherical surface. A runner system is provided in the mold for distributing flowable plastic material. A plurality of tunnel gates substantially equally spaced about the perimeter in one of the sections interconnect the inner hemispherical surfaces to the runner system with the tunnel gates being vertically offset from the parting line surface of the two sections. The pins support the solid core in its premolding condition such that the center of the core is slightly offset from the centerline of the mold in the direction of the inner hemispherical surface of the cavity containing the tunnel gates.

Abstract: A method and apparatus are described for forming a closure device having a cylindrical plug and a cylindrical collar extending coextensively and coaxially from a cap. The apparatus includes an outer mold defining an injection mold cavity. A cylindrical hollow outer core extends into the injection mold cavity and a cylindrical inner core extends into the injection mold cavity within the hollow outer core. Pushing means separate the molded part from the inner core. A stripper separates the part from the outer core by engaging an annular shoulder on the part. The part is pushed free of the mold's inner core after the outer mold is removed but before the stripper is advanced to engage the annular shoulder.

Abstract: A mechanical locking mechanism for an injection mold is disclosed for holding a core rod in place in the mold cavity to resist movement caused by the injection molding pressures. The locking mechanism includes a pair of cam shafts, one carried by each of the mold halves, having a cam engagable with a concave recess in the core rod. When the mold halves are closed upon the core rod, the cams engage a portion of the recess surfaces facing toward the mold cavity. The cam shafts are subsequently rotated to move the cams to a second portion of the recess surfaces which is facing away from the mold cavity whereby the cams resist movement of the core rod away from the injection mold cavity.

Abstract: An integrally molded cross-flow fan has a circular array of angularly spaced, radial vanes. The cross-flow fan is molded with a molding assembly having a plurality of gap-forming molds jointly defining mold cavities for forming the vanes. A molten resin material is supplied into the mold cavities to mold the cross-flow fan. Thereafter, a first group of gap-forming molds are withdrawn radially outwardly from between the molded vanes, and after elapse of a period of time, a second group of gap-forming molds, which alternate with the gap-forming molds of the first group, are withdrawn radially outwardly from between the molded vanes. The gap-forming molds of the first group are simultaneously withdrawn radially outwardly, and after elapse of the period of time, the gap-forming molds of the second group are simultaneously withdrawn radially outwardly.

Abstract: A spring member for use in a plastic mold for separating and cushioning parts of the mold, and returning ejector assemblies. The spring member is composed of a hollow cylindrical body with a spring-biased plunger extending a short distance from one end. The spring member is shaped to be installed within a bore in a surface in a mold, with only the plunger extending above the mold surface.

Abstract: A mold forms a portion of a part having a first cross-section of a first thickness further removed from a body of the part than a second cross-section of a reduced thickness. The mold includes pairs of mold pins which are moved between a molding position at which they define a cavity to form the portion of the part, to a release position at which they allow the portion to move outwardly of the mold so that the part may be released. In an embodiment, the mold pins are actuated by a first actuator, and a second actuator actuates a plurality of ejector pins to force the part off the mold. In this way, it is ensured that the part is forced off of the mold, which can then be operated without supervision. In a preferred embodiment, a ramp member moves a holder for the mold pins between first and second positions, which causes the mold pins to move between the molding and release positions.

Abstract: A method of molding a flipper link to reduce or eliminate the tendency of the flipper link to break. The method includes the steps of forming a mold cavity for forming a flipper link having a first end portion, a second end portion and an intermediate necked-down portion. The necked-down portion provides an area between the first and second end portions which more easily twists and absorbs the stress exerted on the flipper link during use. Pins are provided in the cavity for forming an aperture in each of the first and second end portions. Plastic material is injected into the cavity at each end of the first and second end portions such that the plastic material flows into the cavity about the pins and the knit line or lines are formed in the flipper link in a location substantially centrally of the necked-down portion to thereby transfer the stress on the flipper link away from the apertures so as to substantially eliminate the tendency of the flipper link to break about the apertures.

Abstract: Injection molding methods and apparatus for the production of casting molds for toric lenses having ballast oriented properly with respect to the cylinder axis of the toric surfaces. A calibrated rotatable ring mechanism is used within the injection molding body, for producing a slot or other alignment means on the lens casting mold at a point which is offset a predetermined number of degrees from the axis of the toric surfaces being formed in the casting mold. When the casting mold containing a newly cast lens is mounted on a precision lathe, the mating of the slot with a permanent ridge on the lathe spud ensures that the mold seats on the lathe at the same established place each time with respect to the position of the cutting tool. The offset between the toric axis and the position of the cutting tool has already been established, and therefore there is no need for the lathe operator to make any measurements or resetting of the cutting tool.

Abstract: A method of making a measuring and dispensing apparatus molded in one piece for placement in a neck of a flexible wall container is provided. The apparatus has side walls, a base wall, an open top and an upstanding central member which contains a central bore and side or lateral discharge ports for directing the flow of liquid at an angle offset from the axis of the central upstanding member. The method of making the measuring and dispensing apparatus involves injection molding utilizing upper and lower mold halves in conjunction with a center core pin and retractable orifice pins. The center core pin forms the bore present in the upstanding member of the apparatus and the orifice pins form the lateral discharge ports present in the upstanding member.

Abstract: A mold for skin covered foamed plastic molding which utilizes a middle mold to be placed between an upper mold and a lower mold, capable of reducing the weight of the middle mold so that assembling of the middle mold becomes less troublesome, the assemblage becomes more stable and the appearance of undesirable spacing in the assemblage an be prevented. The mold includes an upper mold to be closed over the lower mold, having a bent portion with a bottom surface which is to be a part of molding surface; and a middle mold to be placed between the upper mold and the lower mold, having a hollow region into which the bent portion of the upper mold is to be engaged when assembled.

Abstract: A method provides a mold for producing a product where the product includes material over an undercut opening in the product. The mold comprises first and second mold sections which open and close relative to one another and the first mold section in itself includes mold parts which open and close relative to one another. The mold is arranged such that when the first and second mold sections are closed, the mold parts of the first mold section are also closed to define a mold cavity between the mold sections and further including a cavity region for forming the material over the undercut opening between the mold parts of the first mold section. The mold then opens in a manner in which the first and second mold sections are opened which then allows the mold parts of the first mold section to open for releasing the product from the mold.

Abstract: A mold for skin covered foamed plastic molding which utilizes a middle mold to be placed between an upper mold and a lower mold, capable of avoiding an excessive amount of pressure to be exerted on the upper portion of the lower mold so that the durability of the lower mold can be improved, and preventing gaseous leakage so that the penetration of the liquid foam resin to be poured on a skin cover becomes controllable. The mold includes an upper mold to be closed over the lower mold, having extended side portions which can reach the base of the lower mold when assembled such that the extended side portions can support the upper mold by themselves.

Abstract: An injection mold for forming the halves of a magnetic tape cassette includes stationary and movable molds defining a cavity, and confronting slidable cores disposed in holes extending through the molds. An opaque primary resin is injected into the cavity to form an outer portion of a cassette half with the core faces abutting each other, whereafter the cores are retracted to define a central window cavity in which a transparent secondary resin is injected. A lip surrounds the inner edge of the hole through which one of the cores extends to laterally support and guide the core, and to avoid any jamming or inaccuracy in the retracted position of the core due to thermal expansion.

Abstract: A die casting mold part, which may be mounted on or applied to a die casting mold to provide for the molding and shaping of a variety of projections from the molded article and a simple and sure release from the mold of such projections including a plurality of projections lying closely adjacent to one another and extending outside the mold separation plane. The mold part includes segments, which are received in a bore that guides them and holds them together to form a die casting cavity, the segments together thus forming a mold at one of their ends. On their opposite end they flare outwardly and are mounted pivotally on a central control shaft so that they are caused to be opened where together they formed a mold, by relative movement between the control shaft and bore.

Abstract: An apparatus and method are described for the formation of a three dimensional composite article by use of a flexible male mold placeable within a cavity formed within a rigid female mold. Fibers are initially bound to the surface of the flexible male mold and the mold is thereafter placed inside the female mold cavity. The surface of the flexible male mold is thereafter displaced away from the female mold by the injection of hardenable resin between the molds. The flexible surface is thereafter returned to near its original position adjacent the female mold. The flexible mold includes a chamber defined therein capable of pressurization and depressurization during the fabrication process of the composite article.

Abstract: This invention relates to a mold for making a formed chair arm with passages therein.

Abstract: A pressure slip casing apparatus for producing a sanitary ware such as a toilet bowl, comprises lifting hydraulic cylinder means secured to said top member of a stationary frame; a pair of suspending devices supported by a base plate attached to said lifting hydraulic cylinder means; an interlocking mechanism for operatively connecting said suspending devices to each other; and a hydraulic cylinder device for moving a suspending devices towards and away from each other through the action of said interlocking mechanism. A mold part and a core mold part are attached to said base of said stationary frame and to the lower surface of said base plate, respectively.

Abstract: A die apparatus permits the formation of an internal recess in a molded part. The die apparatus includes first and second mold members which are movable between an open and closed position. A core pin assembly includes a first core pin element and a second core pin element supported between the movable mold members for relative movement therewith. A resiliently deformable element is positioned between the first and second core pin elements. The resiliently deformable element is deformably expandable to form an external projection upon relative movement of the mold members to a closed position, and is elastically returnable upon the relative movement of the mold members to an open position.

Abstract: A mold 300 for making a member having at least one first section of a first material and at least one second section of a second material includes first and second plates or mold halves 332,334 adapted to cooperate with each other when positioned in opposing relationship along a mold-closing axis and reciprocally movable relative to one another along the axis during a molding cycle. The first and second plates or mold halves 332,334 define a member-forming area therein when the mold is in a closed position. Sprues in the first and second plates or mold halves are in communication with the portions of the first and second sections respectively of the member-forming area. An ejector 348 for ejecting an eventually mold member includes one surface defining a boundary of the member-forming area. The ejector is movably disposed in one of the plates and is movable into the member-forming area.

Abstract: A unitary volumetric pipette for dispensing liquids is formed as a unitary structure made from components that have been precision made by an injection molding process and which are bonded together to create an extremely precision fluid dispensing device. The pipette includes a stem portion which is separately formed in an injection molding process and which is bonded, usually through heat bonding, to a bulb portion to complete the pipette. The bond between these two components is sufficiently strong to prevent separation of the pieces and is waterproof to prevent any leakage of fluid from the bulb portion.

Abstract: In an injection moulding tool for the production of a magnetic tape cassette casing constructed, in part, in two layers the apparatus has a fixed core (1a) provided, on the rim, with a projection (5) which provides a sealing strip relative to the moving core (2a). After the injection moulding process into the first mould cavity (4), the moving core (2a) is moved axially downwards by about half the wall thickness, whereupon the second mould cavity (3, 3') is filled by injection through a second needle shut-off nozzle (FIG. 1b).