Abstract: A process for injection molding arcuately-shaped hollow articles is disclosed. The process includes the steps of positioning a stack mold into an injection molding machine. The stack mold has first, second and third mold blocks with the first mold block positioned between the second and third mold blocks. Each of the mold blocks has a plurality of cavities formed therein. The cavities formed in the first mold block are designed to mate with the cavities formed in the second and third mold blocks when the stack mold is closed to form a plurality of arcuately-shaped cavities. The stack mold further contains a pair of slide carriers movably connected to each of the second and third mold blocks and a plurality of inner cores secured to each of the slide carriers. The stack mold is closed by first moving both of the pairs of slide carriers such that each of the inner cores is positioned within one of the arcuately-shaped cavities to form a hollow interior in each of the molded articles.

Abstract: An injection mold assembly including a plurality of mold dies supported for relative movement between a mold open position and a mold closed position, each of the mold dies including a molding surface adapted to form a portion of the surface of a molded article. The mold assembly also includes a plurality of core pins for forming holes in the molded article. At least part of each of the core pins is made of a resilient, non-metallic material. The core pins are supported on one of the mold dies and are engageable with an opposed mold surface when the mold assembly is closed, such engagement resulting in the elastic deformation of the non-metallic part of the mold core pins.

Abstract: A flow control valve including a movable part and a housing for accommodating the movable part may be produced by molding the components in sequential steps. Preferably, the housing is molded in a first step and the movable part is molded in an at least partially closed position in a second step in the same mold. This method enables the surface of the housing to serve as at least a portion of the mold for forming a substantially sealing portion of the movable part such that a very close tolerance between these components is achieved. The movable part is preferably a butterfly disc and the housing is preferably a butterfly valve housing.

Abstract: A method of making plastic molding consists of a boxlike body having an field of multiple fine conical holes. The internal diameter of the fine conical holes gradually decreases from the inner surface of the plastic molding toward the outer surface of the plastic molding, and is in the range 0.1-0.5 mm at the outer surface. The fine conical holes are hardly visible when the outer surface of the box is viewed; ventilation is provided without detriment to the aesthetic appearance of the exterior of the box, and it is not necessary to cover the ventilation holes in the box to keep them out of sight. Conical projection on a male mold are withdrawn before the plastic molding hardens completely and the male mold is separated from a female mold after the plastic material has hardened completely.

Abstract: A wax pattern molding process, employing a mold having a cavity and a core structure in the mold cavity that include closing the mold with the core structure positioned in the mold cavity; injecting flowing heated wax into the mold to flow about the core; allowing the injected wax to cool and solidify to form the wax pattern; removing the core structure from the solidified wax pattern, while the mold holds the pattern in position in the mold; and opening the mold and removing the unencumbered wax pattern from the mold.

Abstract: A molding die having, an outer eccentric ring slidably fitted in an axle hole of a boss molding die assembly of a molding die unit, outer eccentric ring being formed with an eccentric hole the center of which is deviated from the center of the outer eccentric ring, an inner eccentric ring slidably fitted in this eccentric hole of the outer eccentric ring, and a holding pin for holding an insert and slidably fitted in the inner eccentric ring at a point which is deviated from the center of the inner eccentric ring. In adjusting the balance, the position of the holding pin is adjusted such that the center of rotation coincides with the center of gravity of the molded articles. In forming the die, the insert held by the holding pin of which position was adjusted is embedded in the molded article.

Abstract: A plurality of small-sized recesses are provided along outer peripheral edges of the openings of semispheric recessed portions in which a golf ball is injection-molded. These small-sized recesses form small-sized positioning juts along the parting line of a golf ball intended to be injection-molded.

Abstract: A collapsible mold core assembly facilitates formation of features such as channels and undercuts in interior regions of molded articles. The assembly includes a central, fixed pyramidial base member having a first plurality of obliquely oriented channels which receive a like plurality of first mold core segments and a second plurality of parallel channels interleaved with the first plurality of channels. The second plurality of channels receives a like plurality of intermediate members which, in turn, receive a like plurality of second mold core segments. The plurality of first mold segments withdraws from the mold and the plurality of second mold segments, which are constrained to move generally radially within the mold collapse radially inwardly to facilitate removal of the molded part.

Abstract: A cam slide retainer for injection molds including an elongated rounded latch groove formed in the cam slide and a corresponding lock in the core retaining plate. The slide retainer is simple to install since the body portion of the lock is circular and is installed by press fitting into the core retaining plate from the back. A shoulder on the body portion is received in a counterbore to properly position the elongated rounded lock plunger head to extend above the inside surface of the core retaining plate. A flat key surface on the shoulder properly aligns the plunger head to extend transverse to the direction of the slide movement. The elongated rounded groove in the cam slide is positioned to matingly receive the elongated rounded plunger head when the slide is moved to the position away from the molded part to releasably lock the cam slide in position.

Abstract: A molding method and a mold for molding a plastic shutter, wherein a plate-like member with a free end is extended into a molding cavity to define an injection together with at least two opposed planar plates. A thrust member, which is movable in the direction of thickness of the plate-like member and which applies a thrust force to the plate-like member, is provided close to the free end of the plate-like member. In a state where the amount of movement of the thrust member is adjusted to within a predetermined range as viewed in the thickness direction of the plate-like member, on the basis of the position where the forward end of the thrust means comes in contact with the plate-like member, molten resin is injected into the injection space, thereby forming the plastic shutter.

Abstract: An injection molding die for simultaneously molding a plurality of optical disc base boards. The die has a stationary die assembly portion that includes a first base plate having a first center axis, and a plurality of first cavities each having a respective center axis. The first cavities are arranged in an equally spaced relationship along a circumference of a circle coaxial with the first center axis. The die also has a movable die assembly portion that includes a second base plate having a second center axis, and a plurality of second cavities each having a respective center axis. Each second cavity positionally corresponds to a respective first cavity. The first center axis is aligned with the second center axis using a guide rod fixedly secured to the first base plate and that extends along the first center axis, and by using a guide member that extends along the second center axis to be positionally coincident with the first center axis.

Abstract: An injection molding apparatus method and system for molding a plastic article having inward or outward projections on the exterior surface. The injection mold has a first and second mold part adapted to move between a closed, molding position and an open, article-recovering position and which defines a mold cavity for an article to be molded. The first expandable cavity mold part has a base with an opening therethrough and a plurality of outwardly tapered arms extending from the base to an open end that extends into the mold cavity where it is held in place by a striker plate during the injection molding process. The second inner mandrel mold part has a one and other end adapted to move reciprocally and longitudinally within the base and arms of the expandable cavity element, the top end threaded to form the interior threaded surface of the injection molded article.

Abstract: The invention relates to a removable insert for casting molds having a fastening screw for fastening the insert in the mold hollow, which screw can be moved to the fastening position by means of a screwdriver engaging an engagement region. It is provided that the engagement region of the fastening screw is oriented toward the mold hollow, and the fastening screw can be anchored in the inner wall of the mold hollow, that the insert has the cavity for the fastening screw, in which cavity the fastening screw is supported and which Cavity is accessible from the mold hollow to the screwdriver, and that the cavity receiving the fastening screw is closable in an undercut-free manner with respect to the mold hollow. The invention also relates to casting molds, equipped with such inserts, for producing workpieces.

Abstract: The present invention provides an injection molding die unit having a simple construction and an injection molding method employing the injection molding die unit and capable of molding a composite molding in a short cycle time. After molding a first molding (70), a male die (30) is moved together with the first molding (70) by a distance (Gb) in direction (L) and, at the same time, a movable female die (14B) of a composite female die (14) is moved by the same distance (Gb) in the same direction (L) by a coil spring (29) to form a space (72) between the male die 30 and the composite female die (14) consisting of the movable female die (14B) and a fixed female die (14A), and a second molding material is injected into the space (72) to form a second molding (80).

Abstract: The mold that belongs to a cardboard box forming machine is comprised of four forming corners, equal to each other, assembled in such a way that they can be moved longitudinally and transversally in order to carry out the adjustment of length as well as width of the boxes to be formed. The adjustment of length is achieved as a result of the corners being assembled on bushings threaded on spindles, each one of the latter having two sections threaded in a different direction so that the rotation of the former involves contrary movement of each pair of forming corners assembled on each spindle. The adjustment of width is achieved on the grounds of movement of said forming corners along linear guides upon which corresponding bridges slide. Forming corners are also completed with means retaining the box during its formation and pressing means for gluing of the corresponding laps.

Abstract: The present invention relates to an improved apparatus for forming injection molded plastic articles having an inner wall portion. The apparatus includes a mold cavity portion and a mold core portion defining a cavity space in the shape of the plastic article to be formed. The apparatus further includes at least two hot runner nozzles for injecting molten plastic material into the cavity space. The nozzles are preferably offset to outer portions of the mold core portion so as to provide an increased space in the mold core portion in which cooling conduits, inlets and the like can be placed to increase the cooling capability of the mold core portion. The offsetting of the nozzles also provides the mold core portion with increased strength. Each of the nozzles communicates with inner wall portion of the cavity space via a hook-shaped passageway and an inside gate. Additionally, each of the nozzles has a metal portion for maintaining plastic material in the hook-shaped passageway in molten condition.

Abstract: In a device for manufacturing composite plastic mouldings, at least two different reaction mixtures are injected simultaneously through different sprues (24,26) into the cavity (28,28',28") of a mould (20,22). During the injection time of at least one of the reaction mixture, the cavity is subdivided into two or more mutually isolated regions. Following the injection of one reaction mixture, the separation between the regions of the cavity is removed and the at least partially liquid reaction mixtures converge in the separation plane. This device makes possible to join at least two materials having different properties in a single operation. It is useful for manufacturing bumper bars, spoilers, coach-work, and internal linings of motor vehicles.

Abstract: An apparatus for molding a tamper evident closure having a top, an annular skirt depending from the top, and a breakaway band secured to an underside of the skirt by a plurality of bridges includes a mold frame, a cavity portion releasably secured to the frame and configured for forming an outer surface of the closure, a core portion nestable into the cavity portion and mounted on the frame for reciprocal axial movement relative to the cavity portion, a slide portion mounted to the frame for reciprocal movement transverse to the axial movement of the core portion between a closed position and an open position, and a stripper device located on the frame for disengaging molded closures retained on the slide portion as the slide portion moves from the closed position to the open position.

Abstract: An injection molding apparatus is disclosed for forming articles with internal undercuts by the use of lifter heads with transversely extending protrusions. The lifter heads are received in recesses in the mold projections which form the interior of the molded article. The transverse protrusions of the lifter heads extend into the voids surrounding the projections to form the undercuts. The lifter heads are extended outwardly from the projections to remove the article from the mold. Ejector pins move the molded article outwardly from the lifter heads. The lifter head protrusions have inward ramping surfaces which facilitate the removal of the molded article. A lifter head may include two, angularly offset protrusions which form two undercuts near the corner between intersecting internal walls of the molded article. The protrusions have beveled release surfaces which allow the molded article to shift transversely off the lifter heads.

Abstract: A fluid compressor has a cylinder (17), a rotary rod (21), and a helical blade (33) that defines work chambers (44) between the cylinder and the rod. The compressor successively compresses and conveys a fluid from a suction end to a discharge end through the work chambers according to the rotation of the rod. The continuous helical blade is formed by pressurizing and injecting synthetic resin material such as tetrafluoroethylene-perfluoroalkylvinylether polymer resin into a mold through two gates (39), so that a weld line (43) of the blade is located in an intermediate region between a suction pressure region and a discharge pressure region of the blade.

Abstract: A food product package includes a bulky food product hermetically sealed in a bag of heat shrunk film. The package has an integral self-supporting handle which is formed from plies of the film and which extends out from an end of the package in a conventional handle shape. The handle is formed by causing a skirt portion of the bag to heat shrink about a rigid member positioned to maintain the skirt portion spaced from an end of the package during shrinking.

Abstract: A fluid pressure regulator includes a diaphragm operated leakport controlling low liquid or fluid flow rates. A precisely formed leakage unit spaced from the leakport establishes continuous flow from the input to the output. The leakage unit includes a separate orifice unit having an integral molded body and internal precision orifice establishing the continuous flow. A multiple mold core unit for molding an integral body and orifice including a pair of aligned mold cores have opposed planar surfaces located at the orifice plane. A small gap is held between the opposed end surfaces. The orifice unit is molded as a single plastic element without flash at the orifice. The orifice has a diameter in the range of about 0.001 to 0.030 inches, and may be used in various applications requiring precise low flows. The orifice unit may include an elongated tubular body with an internal orifice molded as single integral members.

Abstract: A cap is attached to a mold core with a T-shaped connector instead of screws. The core cap has an air distribution channel and the core has cooling fluid distribution channels which are maximized by using the T-connector. The fluid distribution channels promote maximum cooling of the core, and, along with the air distribution channel, facilitates ejection of small articles from the mold.

Abstract: An injection molding unit has an injection molding machine 1 for injecting a molten resin plasticized in a screw cylinder 4 from a nozzle 9 fitted at the tip of the screw cylinder 4 by advancing a screw 3. An injection mold 31 forms a hollow 36 for forming an injection molded product 35 with a cavity mold 33 and a core mold 34. The injection molding unit further has a pressure relief valve 40 for releasing the resin out of a resin passage when a pressure greater than a predetermined value acts at any point on the resin passage, including the screw cylinder and ranging up to the terminal end of the hollow. The cavity mold 33 is of a split construction, in which a wall portion of the hollow is formed a plurality of segments.

Abstract: In an apparatus for producing flat plastic moldings, for example identity cards, the mold includes a conic core and a die-block member shaped in accordance with the core member. The opposing side surfaces of the core and die-block members, which are inclined to the opening direction of the mold, enclose a mold space on part of their surface. The core and die-block members are formed in such a way that the mold parts brace each other in the closed state.

Abstract: A mold for manufacturing polyurethane parts using the RIM process, has two mold halves which between them enclose a mold cavity. The mold cavity is sealed off from the outside by a sealing surface. A gap of 15 to 30 mm depth and 0.15 to 0.25 mm width is provided between the mold cavity and the sealing surface.

Abstract: An injection molding mechanism and method of its use for the formation in a single sequence of operations of weld-line free cylindrical container body portions having a central opening at one end. The central opening is formed by the removal of the central top sprue portion of the container body. The container body produced by this mechanism can be used as a pressurizable dispensing container.

Abstract: Faster injection molding cycles in an optical disk mold which forms the centerhole by tearing out the sprue can be obtained by increasing the "hot strength" of the sprue by addition of a plurality of rigidifying ribs onto only the B side of the sprue. This plurality of molded-in ribs is formed within a mating plurality of female cavities cut into the axially displaceable ejector sleeve, within which is guided an axially displaceable ejector pin, all within the displaceable half of the moldset. These ribs are circumferentially spaced and extending between the B side displaceable half surface of the sprue flange (substantially located within the plane of the molded disk) and extending substantially downstream to the juncture with the ejector pin surface of the mold.

Abstract: The present invention provides an injection mold having an injection core mold for defining the inner wall of a lip portion in a preform having an undercut, a first lip cavity mold for defining the outer wall of the lip portion having no undercut, and a second lip cavity mold for defining the outer wall of the lip portion having the undercut. In the initial release after the injection molding process of the preform, the second lip cavity mold is first moved upwardly to secure a space wherein there is no obstruction around the outer periphery of the undercut. Thereafter, the injection core mold is upwardly moved such that the second injection core mold can be forcedly released from the molded preform while resiliently deforming the undercut in the outward direction, utilizing the space so formed. The barrel portion of the preform so molded is biaxially stretched to provide a so-called roll-on type biaxially oriented vessel having a ball received in the lip portion thereof.

Abstract: An improved method for generating a toric surface on a molding tool for forming contact lens molds comprises:(a) providing a tool which comprises an elongated body and a molding portion at one end of the tool, wherein the molding portion comprises a surface which is substantially spherical;(b) applying a force to the elongated body so as to distort the spherical surface of the molding portion;(c) machining a substantially spherical curve in the distorted surface while maintaining the applied force; and(d) releasing the applied force, wherein the spherically cut surface assumes a toric shape upon release of the applied force.

Abstract: A product, such as an optical disk substrate, having a minute surface pattern and a central hole is suitably obtained by an injection molding, wherein a resin is injected into a cavity defined by a mold including a movable half and a fixed half. The movable half is provided with an ejector ring reciprocally movable in a mold opening-and-closing direction and a gate cutter reciprocally movable at two strokes in the mold opening-and-closing direction. After the resin is injected into the cavity to form a product accompanied with a gate, the gate cutter is moved at a first stroke to cut the gate. Then the mold is opened, and substantially simultaneously with commencement of the mold opening, the product is released from the stamper and the gate cutter is moved at a second stage stroke in a direction causing the release of the product from the stamper.

Abstract: A drive module of a machine having a turret adjacent the upper end and a motor adjacent the lower end. The turret is driven by the motor to move between different stations of the machine by the controlled rotation of the turret about an axis of rotation. The motor includes an upwardly directed output shaft which is in generally axial alignment with the axis of rotation of the turret. An outer housing is disposed between the turret and motor, and the output shaft of the motor is connected to an inner housing disposed for rotation within the outer housing. An elongate shaft extends axially through the inner housing and is connected with the turret to transmit movement of the shaft to the turret. A force transmitting member is connected to the inner housing and to the elongate shaft for transmitting rotational movement of the inner housing to the elongate shaft, and for permitting axial movement of the elongate shaft relative to the force transmitting member and the inner housing.

Abstract: In accordance with the present invention there is provided a new and improved internal core lifter for molding and ejecting plastic parts having undercuts. The preferred internal core lifter has a core blade with a first end configured to cooperate with the surfaces of the mold for molding a plastic part and for assisting in safe ejection of the plastic part. The core blade may be pivotally mounted at an opposite end for being disposed at a predetermined molding angle in a range of angles for accommodating various molding angles of mold apparatus. In ejecting the plastic part, the first end of the core blade moves horizontally away from the undercut while moving vertical to assist in safe ejection of the plastic part.

Abstract: A slide retainer for an injection mold tool with positive locking, recessed mounting, and guide bar capabilities. The retainer includes a track channel insert rigidly mounted in the base plate of an injection mold tool and a cooperating cylindrical insert mounted for rotational movement in the slide. The channel insert may be extended outwardly from the base plate to serve secondarily as the slide guide bar. The cylindrical insert includes an eccentrically mounted track pin and a torsional spring thereby biasing the track pin for rotation movement. The channel insert includes a circumferential heart-shaped channel that defines an island in the middle thereof. The track pin extends into the channel and traverses the circumferential path once during each mold cycle. A unidirection flapper gate is provided to route the pin through the channel in the proper direction. Slide retention and locking are achieved when the track pin is oriented in the indented portion at the top of the heart-shaped channel.

Abstract: A method and mold for making an ampule for a needleless or jet injector device. The tip of a core pin is guided into a clearance hole sufficiently large to prevent the tip from hitting the mold cavity. Plastic is injected into the mold and flows into the space between the core pin tip and the clearance hole forming a vestigial nozzle pilot cylinder around and over the ampule nozzle. The ampule is removed from the mold and the vestigial nozzle pilot cylinder is removed to form a finished ampule. A core pin tip is made of drawn wire or is separately replaceable on the core pin. A nozzle of an ampule is cast in place. An ampule is molded with an enlarged nozzle and a separate orifice is installed in the ampule to provide the desired nozzle opening.

Abstract: In a core drive apparatus for an injection molding machine, a servomotor is used as a drive source to drive movable cores which, in conjunction with mold parts, define molding cavities. The servomotor is connected to a control device for controlling the drive of various injection molding machine units including the servomotor. The servomotor is connected to the movable cores by a driven shaft, gears, and screw shafts formed integrally with the movable cores, by attaching a movable mold body to a movable mold mounting section supporting the driven shaft. One end of the driven shaft is fitted on an output shaft of the servomotor attached to a movable platen so that attachment of a mold to the molding machine is facilitated.

Abstract: The present invention relates to a process and apparatus for injection molding thin-walled plastic articles. The apparatus includes a mold cavity and a mold core defining a cavity space in the shape of the article. The cavity space has a circumferentially extending region having a thickness greater than the thickness of a sidewall defining portion. This circumferentially extending region is preferably located at the approximate mid-point of the sidewall defining portion. At least two gates directly and simultaneously introduce plastic material initially into the circumferentially extending portion in a manner so as to minimize the creation of side loads and core shift. After the circumferentially extending region is filled, the plastic material fills the entire cavity space. The plastic material is thereafter cooled to form the desired article.

Abstract: A load carrier 1 of plastic, particularly a storage and transporting box or container as well as a pallet or shelf, is suggested in which a base 2 having a planar upper surface is stabilized on the underside by stiffening ribs 3 and in which flat foot strips 5 lying in the direction of the base plane extend at least along two defining edges 4 of the base 2 running parallel to one another, are supported at a distance below the base plane by webs 6 directed transversely relative to the respective defining edge 4, and form stand surfaces of the load carrier 1, wherein there are free spaces 7, 7a between the underside 2a of the base, the upper side of the foot strips and the transversely directed webs 6, which free spaces 7, 7a are enclosed to form pockets and are open at least toward the defining edge 4.

Abstract: A mold for making a seal for garment labels, the seal including a base body (11) and graft type elements (12) connected to the ends of a cord or thread (10) and insertable into the base body for connecting thereto. The graft type elements (12) engage in a seat (13) through opposite openings in the base body (11) and have resilient fingers (15) which hook into undercuts (14) in the seat (13) to prevent removal. The seat (13) extends longitudinally within the base body (11) and opens at the ends into openings in opposite side walls of the base body each opening defining with the seat an undercut (14) facing the opposite opening.

Abstract: A method of molding a ferrule of plastic resin provided with at least one hole having a small diameter and positioned at a predetermined position by a mold having a pair of associated molding ferrule halves, including the steps of arranging a molding core having at least one pin for defining the hole in a cavity defined by the pair of molding ferrule halves, holding the molding ferrule halves by a clamping force, the molding ferrule halves having inner members for positioning the pin and being free from the clamping force, supplying plastic resin into said cavity and pressing the inner members of the molding ferrule halves by a force separate from the mold clamping force.

Abstract: A brush holder structure in an electric motor in which brush holders for housing brushes held in slidable contact with a commutator provided on a rotor shaft and an end bracket for rotatably supporting the rotor shaft are both integrally molded with a gear frame for housing and supporting a worm gear mechanism. In addition to the main mold for molding the gear frame, two first molds and two U-shaped second molds are abutted so as to form the brush holders when the gear frame is molded. A projection extending from each of the first molds extends between the arms of the associated U-shaped second molds to form a lead-out groove for leading out a pig tail extended from each brush.

Abstract: An open and shut molding method of making a paint roller bearing with offsetting core support surface for use in paint roller applicators that permit the user to change a paint roller quickly and efficiently on a paint roller applicator by bringing together a first mold and a second mold until a portion of the molds contact each other to thereby provide central regions in the mold cavity to exclude moldable material therefrom and then flowing a moldable plastic material into the mold cavity formed between the first mold and the second mold and separating the first mold from the second mold to enable removable of a ready to use molded one piece paint roller bearing housing having a central opening extending therethrough for inserting of a shaft therein for rotatable supporting the ready to use paint roller bearing housing thereon.

Abstract: The dimensions of an injection molded hollow plastic product having laminated walls is controlled and the separative forces exerted against mold sections during molding of the products within a cavity of a mold having a core section and a cavity section defining the mold cavity therebetween, are reduced by methods including the steps of (a) injecting a first plastic material into the mold cavity; (b) cooling the injected first plastic material in the mold cavity; (c) injecting subsequent to injecting the first plastic material, a second plastic material into the mold cavity so that the cooled injected first plastic material is sufficiently solidified to stabilize the core section in relation to the cavity section by impeding movement of the core section in relation to the cavity section caused by injecting the second plastic material, whereby the injected second plastic material further fills the mold cavity; and (d) cooling the injected plastic material in the mold cavity to thereby solidify the molded produ

Abstract: Injection molding takes place in a molding chamber which is formed between a core-defining member as part of a mold core assembly and a cavity-defining member as part of a mold cavity assembly. One removes a first mold core and mold cavity-defining member from the mold core and mold cavity assemblies when desired molding by means thereof has been accomplished, and replaces them with a new core-defining member and cavity-defining member to form a molding chamber of a different design. These are respectively secured to the remainder of the mold core assembly and mold cavity assembly, so that the main portions of the mold core and mold cavity assemblies may be retained in a mold press, and differing products may be manufactured.

Abstract: An injection molding machine employing a mold for molding, e.g., disk-shaped recording medium carriers. A mold-mounting plate has a front surface allowing the mold to be the mounted thereon. A gate-cutting punch is slidably inserted in a hole extending through the plate and opening in the front and rear surfaces of the plate. A bore extends longitudinally in the center of the punch, and an ejector pin is slidably inserted in the bore. A gate-cutting drive cylinder is mounted on the rear surface of the mold-mounting plate, and has a piston capable of abutting against the rear end of the gate-cutting punch. The piston is formed with a stepped bore having a large-diameter front portion and a small-diameter rear portion which are aligned on the same axial line. An ejector rod extends through the stepped bore, and has a large-diameter portion slidable within the large-diameter portion of the stepped bore, the front end of the ejector rod being capable of abutting against the rear end of the ejector pin.

Abstract: The invention includes a system for producing a monolithic injection molded pipette including a mold having an elongate cavity enclosing a prolate core, both cavity and core having tapered ends, paired retractable locking pins for stabilizing the core, solonoid drives for extending and retracting the pins, a resin source for for injecting resin into the cavity, and a controller for retracting the pins as injected resin flows along the core to the space proximate the pins. The invention includes a method for making a pipette including enclosing an elongate, tapered core in a mold having a prolate, tapered cavity to accept the core, extending paired locking pins to stabilize the core, injecting resin into the cavity and sequentially retracting the locking pins as the resin flows in the cavity proximate the pins. The pipette according to this invention is an injection molded monolithic structure comprising an elongate tube and a tapered tip formed integrally with the tube.

Abstract: A pressure molding apparatus for supplying molten resin to a mold includes a gate unit having an aperture therein for passage of molten resin into a mold cavity of the mold, a gate pipe connected for communication with the gate unit, and a gate pin which is axially movable within the gate pipe. The gate pin has a gate pin end at one end and a tip at another end thereof, the tip being engageable with the aperture for controlling flow of molten resin through the gate unit. The apparatus also includes a manifold pipe for supplying molten resin to the gate pipe, a connection arrangement for connecting the gate pipe to the manifold pipe. The connection arrangement includes a receiving portion for receiving molten resin from the manifold pipe, the gate pin passing completely through the receiving portion and the gate pin end extending beyond the connection arrangement.

Abstract: A multi-cavity injection molding apparatus capable of simultaneously molding a plurality of optical disk substrates with a simple construction. The injection molding apparatus is constituted of a mold unit having a plurality of cavities and an injection unit for supplying a molten resin to the mold unit. The injection unit is provided with a plurality of nozzles for injecting the molten resin into the cavities, respectively.

Abstract: An angle pin assembly for use in an injection mold having a cam slide. The angle pin assembly includes a bushing and an angle pin. The bushing is received in a bore that is made perpendicular to the planar surface of a cavity retaining plate. This perpendicular bore can be made using a CNC machine so that all machining can be completed on a single machine. The bushing includes an angled bore for receiving an angle pin. The angled bore in the bushing is aligned with an angled pin receiving opening in the cam slide so that normal movement of the mold when opening and closing results in lateral movement of the cam slide away from and toward the molded part.

Abstract: An injection molding system is used to mold a preform having an undercut. The molding system includes an injection core mold, and three injection cavity molds, which are a neck mold for defining a neck of the preform, a first cavity mold including two mold halves for defining an outer wall of the preform having the undercut, and a second cavity mold for defining a remaining outer wall of the preform. The molding system also includes a clamping unit for opening and clamping the foregoing molds and a mold half opening mechanism for opening and clamping mold halves of the first cavity mold.