Abstract: A mold utilized for creating a fishing worm having an abdominal cavity that contains an attractant gel having a stimulating taste to a fish, the mold having first and second sections, with each section having a cavity portion. Each cavity portion of the mold represents a part of a desired worm configuration, with the cavity portion of one mold section being able to be brought into careful alignment with the cavity portion of the other mold section, after which molten plastic can be injected into the completed mold cavity constituted by the aligned cavity portions of the first and second mold sections. An elongate plug held in place by a small diameter supporting member is mounted in a mid portion of the cavity of the first mold section, at a position corresponding to the abdominal region of the worm to be created.

Abstract: In a method of injection molding a tie that includes an abutment wall surface having at least one tooth inside a locking head facing a pawl, a first mold part defines a portion of the abutment surface that includes the at least one abutment surface tooth and a second mold part defines at least a portion of a surface of the abutment wall that is on the opposite side of the abutment wall from the portion of the abutment surface that includes the at least one abutment surface tooth. The first mold part is separated from the second mold part while retaining the abutment wall in the first mold part to separate the second mold part from the opposite side of the abutment wall to thereby enable the abutment wall to flex in a direction away from the pawl into a space vacated by separation of the second mold part from the opposite side of the abutment wall so that the tie can be removed from the mold without significantly damaging the at least one abutment surface tooth.

Abstract: A model for a casting mold, particularly for the casting of blade wheels for turbo-engines, includes multiple cores which can be fitted into one another. The cores have exterior rings, portions of blade duct cores and connector plates. The portions of the blade duct cores supplement one another.

Abstract: An assembly for manufacturing a plastic piston using a first mold and a second mold, each mold having an axial recess, centering element, core element and contact face. The second mold is movable toward and away from the first mold and can be connected to the first mold using a transverse slide on the first mold and a holding apparatus.

Abstract: A molded article having a large undercut part is efficiently produced by a method of molding a synthetic resin with the use of an apparatus comprising an outer mold (S) and an inner mold (N) arranged so as to form a cavity (C) inside the outer mold (S), said inner mold (N) comprising a central mold segment having a part whose size is reduced toward its head and mold segments (6, 7) for forming an inner surface of a molded article which are supported so as to be able to meet and get apart from each other around the central mold segment (4) and divided into a plurality of separate segments, wherein said mold segments for forming the inner surface of the molded article are rendered movable toward the center of the apparatus by moving the central mold segment and wherein the inner mold (N) is withdrawn in the form of its size reduced as a whole from inside the molded article (21) supported in the outer mold (S).

Abstract: This invention relates to a device to compact parts with an undercut out of powder metal, including a pair of dies linearly moveable relative to one another and then phased, and an associated linearly displaceable pair of punches to produce said parts with said undercut.

Abstract: A molded container top 140 has engravings 145 formed by an embossing 108. The core 120 withdrawn from the cavity 102 and a retaining ring 110 holds the hot molded part 140 in the cavity 102. The molded part 140 shrinks away from the cavity 102 and is pushed out of the cavity 102 by an ejector 105. The part 140 has no witness lines on its circumferential skirt 142.

Abstract: In a method of injection molding a tie that includes an abutment wall surface having at least one tooth inside a locking head facing a pawl is formed in a mold that defines a tie in which the abutment wall includes at least one bulge adjacent each of opposite ends of the abutment wall for holding the abutment wall in the respective mold parts when the mold parts are first separated, with the at least one bulge adjacent one end of the abutment wall being defined by a first mold part and the at least one bulge adjacent the opposite end of the abutment wall being defined by a second mold part. As the first and second mold parts are being separated, the bulges initially hold the abutment wall in the respective first and second mold parts and thereby stretch and reduce the thickness of the abutment wall so that the tie can be removed from the mold without significantly damaging the at least one abutment surface tooth.

Abstract: To reduce the need for manual work, improve productivity and reduce the fabrication cost in the method for molding a lead screw for converting a rotational movement into a linear movement, there are provided a method and a die assembly which may involve the steps of forming a plurality of holes in a wall of a tube in a spiral arrangement, preparing a metallic die assembly provided with a cavity defining a thread groove adapted to form the thread crest matching in position with an array of the holes, placing the tube in the cavity, and injecting synthetic resin material into the cavity so that the synthetic resin material may flow in two separate flows, one flowing inside the core tube, and the other flowing along the outer surface of the core tube. The thread crest is connected to the synthetic resin material filled in the core tube, and can be securely attached to the core tube. Optionally, an annular rotor may be fitted onto the base end portion of the lead screw.

Abstract: A article with interior interrupted threads and a mold apparatus for manufacturing the same is provided. The molded article includes an aperture positioned completely therethrough as defined by an inner wall. The inner aperture wall carries a series of thread segments positioned about the periphery of the inner wall to form an interrupted helical thread line. The thread segments create a female threaded aperture through the molded article for receipt of a male threaded member therein. The mold apparatus includes an upper half and a lower half. The upper half carries a cylindrical wall which is notched with its upper edge being beveled .outwardly. The bottom half also carries a cylindrical wall which is notched as well as beveled outwardly.

Abstract: A method and apparatus are provided for injection-molding a unitary, relatively rigid thermoplastic device having a field of injection-molded hooks integrally formed in predetermined areas on the device during the injection-molding of the device for releasable attachment to an associated co-operative loop bearing member.

Abstract: The invention relates to an apparatus for making hard sided luggage shells and other containers by vacuum forming or pressure forming thermoplastics. An apparatus for making shells and containers with integrally molded frames is disclosed. An apparatus for manufacturing differential pressure formed containers with framed openings, without the need for later attachment of a separate frame element to the molded shell. An apparatus also is disclosed for reducing the undesirable stretching of shell material that occurs during differential pressure forming, particularly the thinning of corner portions of the shell or container. The apparatus of the invention more efficiently utilizes the thermoplastic material by moving material from otherwise offal portions into the molded product. An improved device for severing the offal material from the final product is disclosed.

Abstract: A molded pinion includes separate gear portions with gear teeth, and gearless shaft portions provided between the adjacent gear portions. The shaft portions have an outer diameter smaller than the dedendum of the gear teeth of the gear portions. Each shaft portion has an axial length longer than an axial length of each gear portion. Disclosures are also directed to a molding die assembly including first split dies which are movable in radial directions to form the gear portions of the pinion, and second split dies which are movable in radial directions independently of the first split dies to form the shaft portions, and a molding method using the molding die assembly.

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: First and second mold members are fitted one within another and together define a first annular space for forming a discontinuous single thread in a thin-walled housing, as well as a second annular space coaxial and contiguous with the first annular space; the second space defines the thread on the interior wall of the housing in the form of teeth members for receiving a threaded member associated with a linear adjustment device used with an agricultural implement, such as a spreader.

Abstract: A tank for a heat exchanger is made of resin as a unit by molding with a pair of forming dies and includes a fit base portion for supporting an end of the tube portion to keep a fluid communication between the tank and the tube, and a box-shaped receiving portion integrally formed with an outer side surface of the tank to receive a fastening part. The receiving portion includes a bottom wall extending horizontally, a front wall extending vertically from a front end of the bottom wall and a pair of side walls extending vertically from side ends of the bottom wall in a manner to form a top opening thereby. A notch portion is provided at the front wall and the bottom wall in such a manner that the notch portion extends from a middle portion of the front wall to the bottom wall. The receiving portion for receiving the fastening part can be structured as a unit with only a pair of dies and without an additional mechanism.

Abstract: A method for manufacturing a long size non-ceramic insulator is provided. The method includes the first step, in which a rubber housing having a plurality of trunks and skirts is formed around a long size core while molds are tightly assembled, and 1 second, in which the long size core is moved a length corresponding to the rubber housing while the molds are separated. Further according to a third step, the long size core is set in a position in the molds as the distal portion of the formed rubber housing is clamped by positioning jigs disposed in the molds while the molds are tightly assembled. While the rubber housing is clamped, the next continuous rubber housing is formed around the long size core, which will be connected to the last formed rubber housing.

Abstract: The present invention is a mold apparatus and method for injection molding a plastic part. A cavity mold part defines at least one main cavity. A core mold assembly has surfaces complementary with the main cavities. The core mold assembly includes an outer core mold part having a center opening. An outer ejector part is positioned for movement in the center opening. An inner stem ejector part is positioned within the outer ejector part. The cavity mold part and the core mold assembly are moved together and the thermoplastic material injected to form the plastic part. The cavity mold and the core mold assembly is separated. The outer and inner ejector parts are moved together and away from the outer core mold part. Preferably a stripper part rotates a portion of the formed part. The inner stem ejector part is then moved relative to the outer ejector part and completed plastic parts removed.

Abstract: An apparatus for manufacturing an injection molded steering wheel pad having a cover and a pocket formed between a first projection and a second hook-shaped projection, that together hold an arm of an air bag device. The apparatus includes fixed and movable mold members opposed to one another. The movable mold member moves along a predetermined moving path to selectively contact and separate from the fixed mold member. Core members are provided in one of the mold members for forming the first and second projections in the pad. The core members are movable between retracted and extended positions with respect to one of the movable and fixed mold members so that the formed pad projections can be separated from the mold by varying movements of the core members, relative to each other and the mold in which they operate.

Abstract: Toy mold systems usable by a child to form highly detailed, rigid molded toy figures are disclosed. The systems include at least three preformed mold sections each having a configuration such that, in an assembled condition of the toy mold system, they define a mold cavity having at least one undercut. The mold system includes structure for releasably engaging the at least three mold sections in the assembled condition of the toy mold system. In the preferred embodiments, the mold system includes a base, top, and four wall mold sections. One, and preferably all, of the wall sections have a cavity portion with undercuts which provide the detailing on the sides, front and back of the molded toy figure. One of the mold sections functions as a base section into which the other mold section nest and with which they are releasably engaged.

Abstract: An apparatus for molding a synthetic resin screw includes upper mold members 2 and 4, lower mold members 3 and 5, and four sets of slide cores 2a, 4a, 3a and 5a supported by the respective mold members and withdrawable in directions parallel to a parting plane between the upper mold members and the lower mold members.

Abstract: A modular mold assembly for use in injection molding and method of use. The modular mold assembly comprises a fixed side and an ejector side and a plurality of interchangeable modules for shaping a plurality of sides of a component attached to the mold assembly. The modules include blank modules and slide modules. The interchangeable modules are attached to the mold assembly by slide retainers attached along an interior surface of the ejector side. Slide actuators are attached to the fixed side for engaging the slide modules. The slide actuators move the slide modules inward when the mold halves are pressed together forming a mold cavity and move the slide modules outward when the mold halves are separated.

Abstract: A core ring assembly for use in production of a plastic injection-molded component is formed by injecting molten metal alloy into core dies to produce two intricately shaped ring type elements--one male, one female. Removing the male and female ring elements from the core dies and combining the two elements in an assembly machine to form a uniform, geometrically symmetrical, integral core ring assembly. The core ring assembly is transported to a plastic molding machine for overmolding the core ring assembly with either thermosetting or thermoplastic material. Then, the core assembly is melted out from the plastic component in a hot oil bath or induction melt-out, and the molten alloy recovered thereby is returned to a molten metal alloy tank for reuse.

Abstract: An injection-molding apparatus for making a hollow-wall container having sides and a base has front and rear mold parts together forming side surfaces of a mold cavity centered on an axis and a floor mold part defining a base surface of the mold cavity. An inner core sleeve and an outer core sleeve are axially displaceable relative to each other and to the mold parts and have front ends. The sleeves together form a passage extending to the front ends and the front ends form a compartment. A sleeve actuator can displace the sleeves axially between a front position with the front ends of the sleeves projecting relatively far into the cavity and a rear position with the front ends of the sleeves generally retracted from the cavity. A piston/cylinder unit formed between the sleeves connected to the passage is pressurizable to shift the sleeves relative to each other and thereby open up the compartment into the cavity. A floor actuator can axially shift the floor between front and rear positions.

Abstract: Apparatus includes a female mold and a mold core cooperating with the female mold to form a mold cavity therebetween in the mold closed position for the formation of a threaded, mold article therein. A movable, rotatable stripper ring is provided over the core, and the stripper ring is rotated from a rearward to a forward position and thereby remove the threaded article from the mold core by rotating same.

Abstract: A mold construction for allowing molding of parts having elements with a helical configuration. The helically configured portion is formed by a portion of the mold that is freely rotatable relative to the rest of the mold about the axis of the helically configured portion. The extraction of the molded component from the mold along a path coextensive with the axis of the helically configured portion produces driven rotation of the rotatable mold portion thereby releasing the molded component.

Abstract: An injection molded metal mold is provided to eliminate defects such as appearance defects of molded products, functional defects of products, or the like, caused by formation of a concave portion in a surface opposite to a gate as a metal mold is used over a long period of time. An injection molding metal mold 1 in which when a melted resin is injected first from a gate into an injection cavity, the rate of resin at the gate is not less than 5 m/sec, and the distance between the gate 5 and a portion opposite to the gate is 0.2 mm to 2.0 mm. In the mold, an exchangeable gate-opposition metal mold member, in the form of an ejection pin, is buried in the portion opposite to the gate. Further an injection molding method using this metal mold is provided. The forward end of an ejection pin bites into a plastic molded product so that the molded product is held ejected when the metal mold is opened.

Abstract: The present invention provides a preform used to mold a container with hanger. This preform has a cylindrical bottomed barrel portion, a flat plate-like hanger having a central opening formed therethrough and a connection formed on the bottom wall of the barrel portion substantially at the center thereof, the connection connecting between the hanger and the bottom of the barrel. When this preform is injection molded, a molten plastic material is charged into the mold cavity through a gate communicating with the end of the hanger. The molten plastic material is divided into two branch streams at the hanger molding cavity region. These two streams are re-combined at the connection. The connection is of substantially circular cross-section and functions as a gate for permitting the molten plastic material to flow into the barrel molding cavity region.

Abstract: An expandable cavity core element for use in a method and system for molding a plastic article having inward or outward projections on the exterior surface. The injection mold has an expandable cavity core element 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 cavity element 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 cavity element has an outer, tapered exterior surface length which is always equal to or larger than the total molding length of the interior molding cavity. The cavity element may include an outwardly tapered exterior surface or a multiple-tapered exterior surface, such as an outwardly tapered surface and then an inwardly tapered surface.

Abstract: A mold for forming an article having one or more substantial radial protrusions. The mold includes a core movable along a molding axis, a stripper ring movable a limited distance along one set of guide rods with axes parallel to the molding axis, a split ring having segments movable adjacent to the stripper ring for the limited distance and movable relative to the stripper ring on a second set of guide rods at an angle to the molding axis, and a cavity. The article is removable from the mold when the core is moved away from the cavity, the stripper ring is moved its limited distance, and the split ring segments are moved with the stripper ring and then relative to the stripper ring at an angle to the molding axis.

Abstract: The manufacture of slit-type zip fasteners is accelerated by synchronizing the movement of the slit former with the movement of the ejector. A portion of the slit former slides while ejecting the product or closing the mould in a guide which causes a movement of the slit forming portion of the slit former obliquely to the general ejection direction thus pulling the slit forming portion out of the heads of the zipper teeth. The zip fastener is made preferably in a mould wherein the slider that comprises inter alia the moulds for the zipper stops is disposed asymmetrically at one end of the mould. The hot runner of this mould is designed in such a manner that the material flow is first directed to the feed nozzle furthest away from the slider and then to the nozzle next to the slider which is working for the injection moulding of a zip fastener of any length.

Abstract: Disclosed is a new method for making a component having interior and exterior threads. Such method includes the steps of providing a thread-forming apparatus having first and second circumferential threaded portions defining a space between them. Such space is filled with a flowable material, e.g., hot plastic, which is permitted to solidify and form the component. The apparatus and the component are then separated from one another by rotating such apparatus so that both threaded portions unscrew from the component. The finished component has interior and exterior threads which are simultaneously formed and substantially free of flashing. The new thread-forming apparatus has a first threaded portion and a pocket. A plug is in the pocket and has a second threaded portion spaced from the first threaded portion.

Abstract: A tamper-evident thermoplastic fitment having a spout and a closure for said spout are welded to a polymer-coated paperboard container or to a flexible plastic container. The fitment and closure are initially molded simultaneously but with a substantial space between the two parts interconnected by an elongated runner which conducts molten plastic from the closure to the fitment. Upon retraction of the core of the mold, the closure is pulled into the spout until shoulders on the parts engage, whereupon the closure is stripped from the mold core. The runner comprises a tear tab which slides through an apertured space on the closure. When the parts engage tangs on the tear tab engage the space, making the assembly tamper-evident. The fitment has a flange which may be welded or otherwise secured to the container. The tab may be pulled by the consumer to open the container. The closure may be unscrewed from the spout or otherwise disengaged.

Abstract: A method of forming a hydrostatic nut that cooperates with a lead screw for translating a wheel head, or carriage, on a grinding machine, such as a cam grinder. A lead screw, which is externally threaded, is inserted into a cylindrical mold, which is internally threaded. The lead screw is retained therein by pressure plates that seal off opposite ends of the open bore of the mold.A continuous cavity is defined between the internal threads on the nut and the external threads on the lead screw. An epoxy resin or other castable polymer is introduced through an inlet port in the mold into the cavity. The castable polymer is allowed to cure into a rigid mass that adheres to the internal threads on the mold. The lead screw is removed, and the mold may be machined to its final configuration as a hydrostatic nut.At least one helical channel is defined in the outer surface of the rigid mass adhered to the mold.

Abstract: A helical structure having a shaft defining an axis of rotation and a substantially helical flight extending about the axis of rotation and composed of a plurality of sections each having a segment disposed in substantially right angular relation to the axis of rotation. A method for manufacturing a helical structure or the like including the steps of producing a mold having a mold cavity defining a configuration for the helical structure having a substantially helical flight composed of a plurality of sections having segments disposed in substantially right angular relation to an axis of rotation for the helical structure, introducing a moldable substance into the mold cavity to form the helical structure in the configuration and removing the helical structure from the mold cavity by separating the mold along a path substantially aligned with the segments.

Abstract: The invention relates to a device for thermoforming a pouring spout from a sheet of thermoplastic material. The device includes a forming tool for engaging a first side of the thermoplastic sheet and a tube for advancing an outer closure portion or a screw cap to a second side of the thermoplastic sheet. A spacer ring of resiliently yieldable material is positioned on the advancement tube. A neck of the pouring spout is created between and upper side of the package and the outer closure portion or screw cap.

Abstract: Described is an injection molding mold for the production of fittings from thermoplastic material which have at least one annular groove at the inside, comprising a mold core which is formed in the region of the annular groove of the molding by segments (8, 8') which can be moved inwardly to such an extent that the mold core can be moved out of the annular groove in the axial direction, wherein the inward and outward movement of the segments (8, 8') is produced by rotation of a control shaft (11) and wherein each of the segments (8, 8') which are only radially movably guided in a stationary guide disk (15) is provided with a projection (14) which engages into a guide slot (13, 13') in a control disk (12) which is fixedly connected to the control shaft (11).

Abstract: A method for stripping an open ended bellows part from an injection mold has as a first step the injection molding of a bellows part. The bellows part has a resilient portion located between a core pin and a first split cavity and a substantially rigid portion located between the core pin and a second cavity. The substantially rigid portion has a first open end and an external undercut portion, and the resilient portion of the bellows part has an inner surface and a second open end. The first split cavity opens laterally to permit the resilient portion of the bellows part to be stripped from the core pin. Compressed gas passes through the core pin to the inner surface of the resilient portion of the bellows part while both open ends of the bellows part are closed off by the second cavity and the core pin.

Abstract: A method of molding the main body of a Y-adapter that has a straight passageway extending from one extremity to the other and an arcuate passageway that is generated along the arc of a circle. Core pins for the straight and arcuate passageways are placed in a mold such that they merges together to form a single, smooth lumen in the Y-adapter. The arcuate core pin can be withdrawn from the finished Y-adapter as a result of its circular arc.

Abstract: A method and apparatus for manufacturing a separable fastener which includes a pair of fastener pieces. Each of the fastener pieces includes a flat base and a plurality of elastic engagement projections provided on and integral with the base and arranged in a plurality of lateral and longitudinal rows. The engagement projections have respective heads of a uniform size. Each of the heads is supported on the base via a pair of leg pieces united at the upper end to opposed edge portions of the bottom of the head.

Abstract: A blower having an axial fan driven by a rotating drive source and enclosed by a shroud assembly including a substantially cylindrical fan shroud enclosing an outer circumference of the axial fan, and a protective unit provided with a plurality of support beams extending from the fan shroud toward an air intake side of the blower and cooperating with a plurality of ring-like members so as to form a protective net member for preventing entrance of any unfavorable substances such as foreign matter or a human finger into the shroud assembly, and a plurality of support ribs operating as a physical rib members and as protective members preventing entrance of the unfavorable substances from a radially outer region of the blower into the interior of the shroud assembly.

Abstract: An upper die and a lower die are provided to form a cavity. The upper die and the lower die have respectively slots made through them in parallel with each other, and the slots are connected to the cavity. Also, the slots have pins reciprocatably inserted through them. The pins are reciprocated such that they are advanced to greatly project their ends into the cavity, and that they are returned to allow their head portions to remain slightly projected into the cavity. The pins respectively comprise a body portion in a bar-shaped configuration, a head portion connected to the end surface of this body portion. The end surface of the body portion is furnished with the substantially same radius of curvature as the bottom surface of the cavity. Also, the body portion is shaped in the surface thereof so as to have a circular configuration as viewed from the center of the cavity.

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 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: A device and process for forming threaded molded articles includes first and second mold halves having mold surfaces which are adapted to form a molded plastic article. The first mold half cooperates with the second mold half to form a mold cavity in a mold closed position. A nozzle for injecting plastic material into the mold cavity and a power source for relatively moving the first mold half to a position spaced from the second mold half to form a mold open position, are provided. The device also includes a movable ejection mechanism for loosening the article from the mold surface of the second mold half and for ejecting the article from the mold surface of the second mold half while in the open position. A moving mechanism is connected with the movable ejection mechanism for transmitting power to and inducing motion of said ejection mechanism. An initial source is included which converts the relative motion of the mold halves into power for powering the transfer mechanism.

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: In order to produce a cassette, such as tape cassette, disc cassette or the like, the following steps are taken. First, fixed and movable dies are prepared which are unitable to define therewithin a shaped cavity. The movable die has at its inner surface a retaining ridge which includes a first portion immediately projected from the inner surface and a second portion immediately projected from the first portion. The second portion has side walls at least one of which has a laterally extending projection at the position remote from the first portion. Second, the fixed and movable dies are coupled to define the shaped cavity therewithin. Third, a plastic material is injected into the shaped cavity in such a manner that the retaining ridge is immersed in the injected plastic material. Fourth, the fixed and movable dies are uncoupled and a cured molded article of the plastic material thus produced is released from the movable die.

Abstract: An insert molding machine has first and second mold sections, one of which is movable between open and closed positions, A slide carrying inserts is movable from an open position to a closed position wherein the slide and first and second mold sections define a mold cavity in which a part is molded. A single direction cam mechanism in the slide engages a pin in the movable mold section to releasably connect the slide and movable mold section during closure. The connection causes the slide to open upon subsequent opening of the movable mold section but allows the slide to be closed independently of the movable mold section.

Abstract: A method of forming a hydrostatic nut that cooperates with a lead screw for translating a wheel head, or carriage, on a grinding machine, such as a cam grinder. A lead screw standard, or master, which is externally threaded, is inserted into a cylindrical mold, which is internally threaded. The standard is retained therein by pressure plates that seal off opposite ends of the open bore of the mold. Beads of wax, or tape, or some other rigid instrumentality, are adhered to the exterior surfaces of the helical threads on the standard, while the rest of the standard is treated with a release coating.A continuous cavity is defined between the internal threads on the nut and the external threads on the standard. An epoxy resin or other castable polymer is introduced through an inlet port in the mold into the cavity. The castable polymer is allowed to cure into a rigid mass that adheres to the internal threads on the mold except for the helical beads.

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.