Abstract: A molding apparatus includes a first die having an exterior forming surface and a second die. When the apparatus is closed, the first and second dies define a cavity. A bulge projects from the exterior forming surface of the first die toward the second die. A core receiving section, or a recess, is formed in the second die. When forming a through hole in a molded product, a first core is provided in the core receiving section. The first core contacts the bulge when the molding apparatus is closed. When a groove is formed on an exterior surface of a molded product by the bulge of the exterior forming surface, a second core is provided in the core receiving position. The second core is separated from the exterior forming surface when the apparatus is closed.

Abstract: A molding apparatus and method of injection, compression or otherwise molding a closure having projections extending inwardly from a skirt of the closure includes a plurality of slides for movement obliquely with respect to an inner mold core. A ring contacts the closure and surrounds the slides. Movement of the ring relative to the mold core results in the movement of the closure which moves the slides to disengage recesses on the slides. The recesses are used to form the projections on the closure. The ring contacts the closure and advances the closure away from the mold core. The projections seated within the recesses on the slides move the slides obliquely relative to the mold core and ultimately disengage the recesses from the projections thereby releasing the closure from the mold. The movement of the slides is independent from the movement of the ring so that complicated mechanisms for movement of the slides are not required according to this invention.

Abstract: A molding method and a molding die for producing a lens of a vehicular lamp wherein the lens has an improved appearance in that no weld lines are formed on the surface of the lens and the lens consequently has an improved mechanical strength. The molding die has a gathering area for molten resin in the molding cavity in a flow region of the molten resin to be formed into a lens. A heat insulating layer is formed on a cavity face on the side of the lens surface at the gathering area for the molten resin in the molding die, as a result of which instantaneous cooling is prevented. Accordingly, a skin layer formed on the side of the lens surface at the gathering area is very thin, thereby preventing the generation of a weld line, which could otherwise be generated if thick skin layers produced when high-temperature molten resin directly comes into contact with steel material and cooled instantaneously are gathered together.

Abstract: Contacts connected to wires are set in a lower mold and an upper mold is then fitted on the lower mold. The upper and lower molds include contact restraining portions and wire restraining portions, and upper mold holding members and lower mold holding members extending into the cavity at opposite positions enabling these holding members to restrain the wires. The upper and lower molds further include elastic members arranged to urge the upper and lower mold holding members into the cavity of the upper and lower molds for restraining the wire before an insulating plastic material is poured into the cavity. Either of the upper and lower mold is provided with a contact positioning portion adapted to abut against distal ends of the contacts for positioning the contacts relative to the molds.

Abstract: An injection molding system for molding a hollow plastic article employs a hollow mold core having a longitudinal axis and a core runner cavity that has a uniform cross section throughout and which extends to the open end of the mold core. The mold core includes at least one core ejection gate and at least one core inlet gate leading from the outer surface of the core wall to the core runner cavity. When molding is performed in stages, there is it least one core ejection gate for each stage of molding. The core is clamped in between separate sets of molding blocks for each stage of molding. A core end closure cap having a core extension cavity aligned with the core runner cavity is used to close the open end of the mold core. A molten plastic is injected into the outer molding blocks and is confined to travel through the core inlet gate of the core without entering the mold cavity directly so that the molten plastic is forced to pass through the core runner cavity in order to reach the core ejection gates.

Abstract: A method for manufacturing an optical connector ferrule according to the present invention is a method for manufacturing an optical connector ferrule where a plurality of fiber holes are arranged between two guide pin holes, wherein melted material resin is injected from one resin injection port into a cavity of a forming mold where two forming pins for forming the guide pin holes and a plurality of forming pins for forming the fiber hole are arranged in parallel to one another. A forming mold according to the present invention is provided with a cavity where a plurality of forming pins can be arranged in parallel to one another, and one resin injection port through which melted material resin can be injected into the cavity.

Abstract: An injection molding apparatus has a non-metallic injection mold and a pressure relief valve for handling excess resin pressure in the cavity mold. The pressure relief valve responds to excess resin pressure in the hollow by providing an alternate resin passage for the pressurized excess resin.

Abstract: A mold includes a cavity and a core which define a space in which an optical attenuator and supporting portion are formed. The includes a core pin, movably located in the core element. The core pin has a proximal end defining a surface of the lens portion and a distal end remote from the molding space. A core pin motor is coupled to the core pin, through a number of intermediate elements, so that the core pin can be moved relative to the core element to adjust a thickness of the lens portion. The intermediate elements can include a ball screw, a ball screw end cap fixed to a core pin holder block, a ball screw nut fixed to an outer surface of the mold so that an outer end of the ball screw passes through the nut to a location outside the mold.

Abstract: In an internal core lifter for molding and ejecting plastic parts, a core blade having a first and second end section is provided. The first end section is configured to cooperate with a mold used to produce the plastic parts and includes undercut forming portions to produce undercuts in a finished plastic part. At least one mounting member is coupled to the second end portion of the core blade and extends outwardly therefrom. A bracket mountable to a mold ejector plate slidably and pivotally receives the mounting member, thereby coupling the core blade to the bracket.

Abstract: The present invention relates to a method and an apparatus for producing a toothbrush comprising a handle and a brush head provided with a plurality of bristle bundles. A basic body of a brush head is produced preferably from a hard component in an injection-moulding means, the bristle bundles being embedded at their ends in bristle-bundle holding sections which are connected by bridge portions. These bridge portions are cut through and the basic body of the brush head is encompassed preferably with a soft component by injection moulding.

Abstract: Molten resin is injected into a cavity 12 formed between a cavity mold 7 and a moving-side core mold 11 in an injection mold assembly 1 and is allowed to spread out into every corner. Next, after the resin has stopped flowing, punch pins 23 and 24 are pressed into the cavity by hydraulic cylinders 25 and 26 that are attached to the fixed-side mold part 2 side. After the molten resin has hardened, the punch pins 23 and 24 are withdrawn from the cavity, the mold assembly is opened and the molded product is removed. By using the punch pins 23 and 24, through-hole parts are formed in a plate-like product. When the molten resin is injected, inside the cavity there are no through-hole-forming protrusions that would cause the flow of the molten resin to branch, so that weld lines do not appear in the surface of the molded product. As a result, plate-like molded products that include through-holes can be accurately formed by injection molding.

Abstract: A mold for injection molding or diecasting machines, which comprises two closable mold parts defining a die cavity therebetween in a closed position of the mold parts, and inserts slidably movable in rectilinear guides in respective ones of the mold parts. The guides leading into the die cavity have a taper narrowing in a closing direction of the mold parts, and the inserts have guide surfaces Inning at a slant to the taper of the guides.

Abstract: A mold apparatus for forming a pair of mutually opposing guide walls respectively disposed and erected on an upper surface of a half-case of a magnetic tape cassette. The mold apparatus is divided into a third mold and a second mold, and the guide walls to be molded form the boundary between the third and second molds. After injecting resin into the mold apparatus in order to mold the guide walls, the second mold of the mold apparatus is firstly removed in the guide wall erected direction. Then, the third mold of the mold is removed in the same direction, while a distance between the formed guide walls is enlarged by elastic deformation resulting from contact between the guide walls and the third mold.

Abstract: An array of hollow microneedles is constructed of molded plastic, in which a micro-machining technique is used to fabricate the molds used in a plastic microforming process. The molds are detachable and can be re-used. The preferred process for making the plastic arrays of microneedles is a microinjection technique. In the microinjection method, a molten plastic substance is injected between two micro-machined molds that contain microhole and micropillar arrays. Once the desired shape of the microneedle array has been formed, the mold and the plastic material are cooled down. Next, the molds are separated and the plastic microneedle array is detached from the mold structures.

Abstract: A system for molding optical attenuators that have a lens portion and a supporting portion includes a molding machine containing a mold, an extractor robot and optical inspection portion, and a controller that assesses the inspection information and send control signals to the molding machine and mold. The mold includes a cavity and a core which define a space in which the supporting portion and the attenuator are formed. The cavity and core are separable from each other by an actuating motor of the molding machine subsequent to each injection cycle to permit removal of each molded optical attenuator. The mold also includes a core pin, movably located in the core element. The core pin has a proximal end defining a surface of the lens portion and a distal end remote from the molding space. A core pin motor is coupled to the core pin, through a number of intermediate elements, so that the core pin can be moved relative to the core element to adjust a thickness of the lens portion.

Abstract: A manufacturing apparatus for multi-fiber optical ferrule includes a spacer whose hardness is equivalent to or higher than the hardness of pins for forming fiber holes. Further, corner portions with respect to the arrangement direction of the pins for forming fiber holes of the spacer are formed as inclined surfaces or rounded surfaces.

Abstract: The present invention relates to a method of producing an insert-molding product in which an insert product 2 is covered with a synthetic resin by arranging the insert product 2 in a cavity 11 of a mold 10, holding the insert product by a holding pin 12, pouring a molten synthetic resin 3 into the cavity 11, and retracting the holding pin 12. The moving pin 13 is provided adjacent to the holding pin 12. After the cavity 11 is filled with the synthetic resin 3, the holding pin 12 is retracted and the moving pin 13 is moved in the direction of the cavity 11 to extrude and introduce the synthetic resin 3 into the space where the holding pin 12 used to be positioned.

Abstract: An arm head of a windshield wiper device is provided on a backside thereof with an undulated groove formed by sidewalls. The sidewalls have plural hill portions protruding in opposite directions alternately in a width direction of the arm head so as to be opposed to one another in a longitudinal direction thereof. Tops of the hill portions on one width side of the arm head are integrally provided at upper surfaces thereof with projections extending perpendicularly to a depth direction of the groove to overhang the groove. A hose for delivering washer liquid to a washer nozzle is accommodated in the groove and firmly held by the hill portions and the projections without using an extra part such as a clip.

Abstract: A molding die 1 for molding a laminated molding having a molding body with compressible surface members 23 and 24 partially laminated thereonto, where a flow-regulating portion for regulating flow of molten resin flowing toward the surface members 23 and 24 is provided to a die body 10 to regulate the flow of the molten resin flowing on the same plane as the surface members 23 and 24 toward the surface members 23 and 24. Accordingly, since resin lap at an peripheral end portion of the surface members 23 and 24, and position shift of the surface members 23 and 24 by the flow of the resin, laminated molding having good quality and appearance can be obtained.

Abstract: An automobile interior component that includes a honeycomb structure is disclosed. A honeycomb defining structure is formed in one of the mold halves of a mold that is used to manufacture the automobile interior component. The honeycomb defining structure partially defining the article-defining cavity in the closed position of the mold. The honeycomb defining structure comprises a plurality of generally cylindrical recessed areas defined in a portion of said one of said first and second mold halves, and a post member that is disposed in each one of the recessed areas. The introduction of a moldable material into the article defining cavity during the molding process causes the moldable material to flow into the honeycomb defining structure and, therefore, integrally form a desired honeycomb structure as a portion of the automobile interior component during the molding process.

Abstract: A cam slide retainer for injection molds includes a hardened wear plate with an elongated latch groove, mounted in a corresponding recess formed in the lower surface of the cam slide. The wear plate is aligned in the direction of travel of the cam slide and has a length that is no less than the length of stroke of the slide. A conventional spring-loaded plunger mounted adjacent the wear plate remains in contact with the wear plate throughout the stroke of the slide, so that the slide itself is not subject to wear from contact with the plunger.

Abstract: A mould (10) for the injection moulding of hollow products (1) or products with recesses and made from a plastic which quickly expands after removal from the mould, has two mould parts (12, 14) and a one-piece core (18) surrounded thereby. The core (18) within the mould rests with an extension (20) against both mould parts (12, 14). This extension (20) is movably supported on a guide column (22, 24) to be removed from the respective mould parts (12, 14) upon opening of the mould. A compression spring (28, 30) is provided in one of the mould parts (12, 14) which is supported against the mould part (12 or 14) and the core (18).

Abstract: A molding die for shaping a laminated molding including a molding body and a compressible surface member laminated thereonto has centering pins for determining a position of the surface member protrudable and retractable relative to a cavity inside a die body. Accordingly, since the surface member can be accurately and easily positioned and held, position shift of the surface member can be securely prevented. Further, by sinking the centering pins before molten resin is solidified, influence by the centering pins can be eliminated.

Abstract: An injection mould for manufacturing fittings (1) from thermoplastics, which fittings are provided on the inside with at least one annular groove (6), includes a separable outer mould (5) and a mould core (4) which can be pushed into the outer mould (5). A complementary mould bead for forming the annular groove is configured on the mould core (4). The injection mould has a cavity which is formed in the area of the annular groove (6) of the fittings (1) by a plurality of segments (3, 3′) that can be assembled together. The outside surface of the portion of the cavity that forms the area of the fitting (1) surrounding the annular groove (6) is partly formed by the separable outer mould (5) and partly by a mould ring (2) connected to the mould core.

Abstract: A method of producing a bead inductor includes the steps of forming an outer portion outside of a conductor coil, and forming a molded body with the conductor coil embedded therein. The outer portion is formed outside of the conductor coil by disposing the conductor coil in a cavity defined by first and second mold portions, with first and second gates formed in the first mold portion, inserting first and second spacer pin portions, which define a spacer pin which passes through the conductor coil and extends to and closes the second gate, and supplying material containing magnetic powder into the mold cavity from the first gate. The molded body is formed by closing the first gate after the formation of the outer portion, and supplying from the second gate material containing magnetic powder into a space formed by removing the spacer pin portions.

Abstract: The present invention is directed to a mold and method for forming a golf ball with at least a core. The mold and method comprise or use members with projections for forming multiple dimples on the core. The members can be retractable pins or sleeves or vent pins. In the case of the retractable pins, sets of pins with multiple dimple projections on the ends thereof are used to center the golf ball core within the mold. The members can have circular or non-circular cross-sections so that the dimple-forming projections can conform to any dimple pattern.

Abstract: An improved vent pin for a golf ball injection mold is characterized by a non-circular configuration so that a non-circular dimple can be formed at one or both poles of the golf ball. The vent pin is coaxially arranged within a passage in the injection mold which is aligned with a radius of the ball which passes through one of the poles thereof. The pin is operable between a normal position where the end of the pin closes the passage lower end and a retracted position where the pin end is withdrawn into the passage so that air from a cavity of the mold where the cover layer of the ball is formed can be vented during delivery of thermoplastic material to the cavity to form the golf ball cover.

Abstract: In a mold device for injection molding of synthetic resin having a cavity surface alternately heated and cooled and a bottoming structure for producing a product having a bored portion like a window, a bottoming portion for the production of a product having a bored portion is provided on a parting surface of the mold and a vacant space is provided in the bottoming portion. Thus, the contact area of the bottoming portion is reduced and a contact pressure of the bottoming portion and thermal strain due to a temperature difference between the cavity side mold and core side mold are reduced, so that it is possible to prevent occurrence of crack in a portion located immediately outside the window of the product.

Abstract: An apparatus for molding a resin product having a bottom plate, a pair of side plates, and a pair of flanges. The side plates are formed integrally with the bottom plate to extend from opposite sides of the bottom plate. Each flange is formed integrally with the associated side plate to extend inward from an upper end of the side plate. The apparatus has a pair of inner slidable cores that shape an upper side of the bottom plate, an inner side of the side plate, and a lower side of the flange. The apparatus also includes an intermediate core located between the inner slidable cores for determining the position of each inner slidable core. The apparatus further includes a sliding mechanism that slides each inner slidable core to a position spaced from the resin product while moving the inner slidable core and the intermediate relative to each other.

Abstract: An improved golf ball injection mold is characterized by upper and lower support plates each containing corresponding hemispherical cavities which define spherical mold cavities when the plates are brought together. A plurality of retractable core pins are arranged in each cavity for supporting a core of a golf ball. Fluid thermoplastic material is supplied to each cavity to form the cover layer on the golf ball core. A valve pin is arranged in a gate in the upper plate in the center of the upper hemispherical cavity adjacent to a pole of the golf ball being formed in the cavity. The valve pin is operable between extended and retracted positions relative to the gate to deliver the thermoplastic material to the cavity and a closed position intermediate of the extended and retracted positions to stop the flow of thermoplastic material during curing of the cover layer.

Abstract: A sequential mold lifter for a molded part forming device comprises at least first, second and third lifter segments that slidably engage one another. The first and third lifter sections are positioned on opposite sides of the second section and slide upwardly and inwardly on inclined lifter surfaces on the second lifter section. Separate actuators extend all of the lifter sections to a first extended position and then extend the first and third actuators upwardly and inwardly beyond the second actuator to a second extended position. The relative movement of the lifter sections dislodges the molded product from the mold and then dislodges the product from the lifter. The inclination of the actuators can vary with the positions of the lifter sections. Movable slides support the actuators but permit variation in the inclination of the actuators.

Abstract: Injection molding apparatus (10) for molding a thermoplastic article (A) from a moldable thermoplastic material. The molding apparatus includes a core pin (12) around which the article is formed in a cavity that is defined by separable mold halves (14, 16). Moldable thermoplastic material is introduced into the mold cavity, coaxially of the core pin, from an injection nozzle (18) through a restricted passage or gate (20). The nozzle seats solely in a radial extension (16a) of one of the mold halves, which is received in a recess (14a) of the other mold half when the mold halves are closed with respect to one another, and the gate extends solely through the extension (16a) of the mold half (16).

Abstract: The present invention relates to a method and an apparatus for producing a toothbrush comprising a handle and a brush head provided with a plurality of bristle bundles. A basic body of a brush head is produced preferably from a hard component in an injection-moulding means, the bristle bundles being embedded at their ends in bristle-bundle holding sections which are connected by bridge portions. These bridge portions are cut through and the basic body of the brush head is encompassed preferably with a soft component by injection moulding.

Abstract: An apparatus and method for injection molding including at least one nozzle capable of injecting a molten material, and a shuttling system with a first mold part and a second mold part. The first mold part has at least one injection cavity for receiving molten material that is aligned and in communication with the at least one nozzle. The first mold part also has at least a pair of cooling chambers flanking the at least one injection cavity. The second mold part has a laterally moveable shuttle plate with a first mold core and a second mold core. The first and second mold cores are capable of being aligned with and inserted into both the at least one injection cavity and the cooling chambers.

Abstract: A method and apparatus for producing molded fluoropolymer sweep elbows with straight threadable ends that minimizes distortion of the fitting. The apparatus comprises a mold core or insert that is comprised of multiple curved segments which are retracted from the mold individually. The mold core is divided into two or more pieces on a curved plane parallel to the curved central axis of the core and the segments thus formed are retracted from the mold by a combination of arcuate and translational motions to avoid distortion of the fitting ends.

Abstract: A mold clamping apparatus in which hydraulic oil that is forcibly discharged into hydraulic lines from one of two kinds of cylinders, that is, a differential mold clamping cylinder and a mold clamping oil chamber of a mold opening/closing cylinder, is, in an alternating manner, provided to the other cylinder as its operating oil. This feature enables the simultaneous operation of the two kinds of cylinders as well as reduction in operating time in which the mold is opened or closed. The mold clamping apparatus includes a stationary mold, a movable mold which closes with respect to the stationary mold, a core movable through the movable mold into and out of the stationary mold. The movement of the core into and out of the stationary mold is effected by a differential mold clamping cylinder which is separate from a mold opening/closing cylinder for the movable mold and is fitted with a booster ram.

Abstract: A mold and a method for manufacturing a support to be mounted on a rim of a vehicle by injection or transfer molding in which the molding material is force fed into a closed molding cavity. The mold includes an internal core for molding the inner surface of the support, upper and lower platens or shells for molding the body of the support and segments for molding the outer bearing surface. The mold includes a mechanism capable of imparting relative movement to the platens or shells which not only permits opening and closing of the mold but also ensures the specific movements of the core. The core includes at least three separable rigid parts: a center part and at least two complementary parts. The center part has two flat bearings, inclined at the same angle relative to the axis of the mold. These flat bearings are designed to cooperate with corresponding bearings arranged on each of the complementary parts to place the mold in a molding condition or in a stripping condition.

Abstract: A method for molding comprises: passing molding material through a nozzle, a nozzle inlet, and a sprue; diverting the flow of the molding material into a mold cavity with a spreader; and introducing the molding material to the mold cavity. The spreader can be part of the mold or of the nozzle. In one embodiment, the mold can comprise: a mold cavity; a sprue in fluid communication with the mold cavity, the sprue having a nozzle inlet and being adapted to receive fluid from an injection nozzle; and a spreader protruding from an interior surface of the mold cavity opposite the sprue.

Abstract: A dispenser 10 for use in dispensing liquid or solid material. The dispenser 10 includes wall portions forming a sealed first chamber 18 containing the material and wall portions forming a second chamber 20 and a molded, rupturable membrane 34 disposed between the first chamber 18 and the second chamber 20. The rupturable membrane 34 is preferably a circular disk with a series of molded radial depressions 40 or weld seams 40 extending from a center point of the disk. When pressure is applied directly to the membrane 34, the membrane 34 is fractured along the depressions 40 or weld seams 40. A method is provided for forming the dispenser 10 by injection molding.

Abstract: The present invention relates to a retractable pin assembly for an injection mold. One end of the retractable pin is inside the mold, while the other end extends outside of the mold cavity. The inside end of the retractable pin may by shaped to conform with the shape and texture of the mold cavity wall. The retractable pins are moved in and out of the mold cavity by cams that rotate around the injection mold.

Abstract: A liquid container includes a drop dispensing tip with a hollow stem which defines a liquid passageway and an interior partition wall in the passageway. The partition wall separates the liquid passageway into an upstream chamber and a downstream chamber. Flow communication between these two chambers is provided by a liquid passage in the partition wall. The liquid passage guides liquid against an impingement surface in the downstream chamber from which the liquid is dispensed dropwise.

Abstract: A tool with a blade is provided at a molding die and set so as to protrude further inwardly than the molding surface of the molding die. When a parison is expanded within the molding dies, the parison is brought into close contact with the outer peripheral wall of the tool. A hollow body is formed in a state in which the inner wall surface of a through-hole is molded by the outer peripheral wall of the tool. Thereafter, the tool is advanced and a cut-out piece is excised. A washer tank is thereby formed. The inner wall surface of the through-hole is not a cut surface and the through-hole is formed in accordance with the outer peripheral wall of the tool.

Abstract: A resin encapsulation mold of the present invention comprises a lower mold, which is mounted on a lead frame, includes an indentation into which a semiconductor device is placed, and forms a gate through which resin is injected; an upper mold, in which an indentation is formed opposite the indentation of the lower mold to configure a cavity for holding the semiconductor device; a plurality of ejection pins, which protrude from the respective bottoms of the indentation of the upper mold and the indentation of the lower mold into a resin package body formed by injecting the resin from the gate into the cavity, and eject the resin package body; a vertical drive mechanism, which brings into contact and separates the upper mold and the lower mold; and protrusion adjustment means for adjusting the amount of protrusion of the respective ends of the plurality of ejection pins protruding from the respective bottoms of the indentations of the lower mold and the upper mold comprising the cavity while resin is being inje

Abstract: A substantial barrier to flow of liquid in a circumferentially-extending liquid conduit groove of a mold insert is provided by forming recesses or undercuts by undercutting the sidewalls of the liquid conduit groove, inserting a plate-like liquid dam within the liquid conduit groove, and clamping the dam in the liquid conduit groove by the use of a pair of locking screws or pins that extend through bores in the dam into engagement with inwardly-facing surfaces of the undercuts. The relationship between the inwardly-facing undercut surfaces and the locking members is preferably such that there is a progressively increasing interfering engagement of the locking members with the undercut surfaces resulting in increasing clamping pressures applied to the dam assemblies.

Abstract: Disclosed is an integrally molded plastic washing machine tub having a circular bottom and annular sidewalls formed with drain holes, the drain holes being encircled by a tapered, raised annulus on the inner surface of the sidewall. The design of the drain holes allows removal of the tub from the mold following molding, and prevents the snagging of fabrics placed in the tub.

Abstract: An injection molding tool for producing a cage for a linear bearing in which several rolling elements are positioned in the cage in the direction of its longitudinal extent in the assembled state includes two tool halves each provided with protrusions. The protrusions extend into the cavity of the tool during the injection molding process and form a portion of a receiver pocket for receiving a rolling element. To make the injection molding process simple and economical, the protrusions are fixedly connected with the tool halves, with the protrusions being are shaped in such a way that, when acting together, they form holding elements for retaining the rolling elements in the receiver pockets in the cage when the injection molding tool is closed. The holding elements are thus integrated into the basic geometry of the cage.

Abstract: The invention relates to a method of moulding a plastics part (7), in particular a mudguard and panelling parts for motor vehicles, in an injection-moulding method by edge injection moulding via an edge sprue or film sprue (8), wherein the finished plastics part has a visible outside surface (11) and an invisible inside surface, using a tool comprising a core plate (9) and a cavity plate (10), wherein there is formed between the latter a cavity that matches the shape of the plastics part (7).

Abstract: A substantial barrier to flow of liquid in a circumferentially-extending liquid conduit groove of a mold insert is provided by forming recesses or undercuts by undercutting the sidewalls of the liquid conduit groove, inserting a plate-like liquid dam within the liquid conduit groove, and clamping the dam in the liquid conduit groove by the use of a pair of locking screws or pins that extend through bores in the dam into engagement with inwardly-facing surfaces of the undercuts. The relationship between the inwardly-facing undercut surfaces and the locking members is preferably such that there is a progressively increasing interfering engagement of the locking members with the undercut surfaces resulting in increasing clamping pressures applied to the dam assemblies.

Abstract: A valve pin assembly for an injection molding apparatus comprising a valve pin capable of movement up and down in a nozzle to open and close a ring gate. An annular passage is created through the nozzle and is unobstructed and without restriction at all points up to and through the ring gate, permitting melt to flow freely to the gate and, depending on the position of the valve pin, into the mold cavity. The valve pin has a head with a diameter larger than the valve pin shaft for selectively closing the gate. The ring gate channel diameter is larger than the melt channel diameter to permit parts with large apertures therein to be formed.

Abstract: A method of manufacturing a plastics material bellows, wherein a preform is made by molding plastics material in a mold, the mold having preferred deformation zones, and then before the part has completely left the mold, the bellows is formed by folding the preform in the preferred deformation zones, with the resulting bellows being open at both ends.