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 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: 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, molded article therein. A movable, rotatable stripper ring is provided over the core, and a rack and pinion are provided to rotate the stripper ring from a rearward to a forward position and thereby remove the threaded article from the mold core by rotating same.

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: 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: 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 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: 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: 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: 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: An articulated core blade assembly provides improved release of undercuts and similar structures in mold cavities. The articulated core blade assembly includes a retainer secured to an ejector plate, a lifter which moves the product and releases the undercut and a pivot arm which couples the lifter to the retainer. A first knuckle joint couples one end of the pivot arm to the retainer and a second knuckle joint couples the other end of the pivot arm to the lifter. The knuckle joints provide limited pivoting motion about parallel, spaced-apart axes. The articulated core blade assembly may be utilized in a broad range of injection molding machines utilizing plastics, metals and other injection molded materials.

Abstract: A method of injection molding a container cap with a precision thread having a tamper indicating band depending from the bottom of the cap skirt. Collet jaws form at least a frangible connection between the bottom of the cap skirt and the top of the tamper indicating band, and these jaws are moved radially outward specified amounts during the molding process to provide clearance for stripping an inwardly directed retaining element on the band from the core and for ejection of the finished cap.

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: 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: A clutch master assembly made of plastic material for an automotive vehicle. The assembly a plastic cylinder housing (1) and a piston (2) and a plastic bushing (3). The plastic bushing is arranged to allow it to be screwed in by means of a thread portion (4) which is located in the housing. By the screwing-in of the bushing a grooved disc (5) and a grooved cup (6) are secured in the assembly. The grooved cup is furnished with knobs (21, 22, 23) which exert a force in axial direction on the arrangement consisting of the grooved cup (6) and the grooved disc (5). The piston-side enlarged end of the piston rod (31, 104) is secured within the piston (2, 103) by a back injection.

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.

Abstract: In the injection molding of closure caps, the problem of demolding the safety-seal strip, which is suspended at an intended break line and is necessarily provided with undercuts, is encountered. Here a clearance must first be created at the lower outer surface of the safety-seal strip, and the safety-seal strip must then be stripped from the mold core together with the closure cap. As a practical method step, the invention proposes to bring about the release of the lower portion of the outer surface of the safety-seal strip by lowering a mold ring which is displaceable relative to the stripper plate.

Abstract: A heated manifold, for use in the distribution of heated plastic resins to the various cavities of injection molds for thermoplastic materials. The parts of the manifold interlock with each other and contain the high pressures generated by the injection molding presses. The components of the manifold are fitted with seals of metals dissimilar to the manifold, and with a higher coefficient of expansion than the manifold material. The system includes heater bushings which channel the plastic materials to the individual cavities and are fitted with a removable tip which can be adjusted to change the overall length of the bushing. A duct structure provides passages for the heated plastic, and electrical heaters extend generally along the passages, secured in channels in the duct structure by heater covers; a snug assembly of the heaters in the channels provides excellent heat transfer, utilizing heater covers of a metal that is mechanically forced to flow into undercuts in the channels.

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

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

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

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

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

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

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

Abstract: A mold for making bathtubes is disclosed. The mold includes a mold receptor and an insert attached to the mold receptor face. The mold receptor receives a shell which has a finish side and a non-finish side. The shell is placed in the mold receptor leaving a void between the non-finish side of the shell and the face of the receptor. The insert is attached to the face of the mold receptor to reduce the cross-sectional area of a portion of the space between the shell and mold receptor face. A male mold engages the finish side of the shell, sealably retaining the shell to the mold receptor. A polymeric foam material is introduced into the void between the receptor and the shell. The polymeric material fills the void and coats the shell. The molded bathtub is then removed from the mold receptor after the male mold has been removed. The insert is then removed leaving an area of reduced thickness and a periphery on the non-finish side of the molded bathtub which defines a lip.

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

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

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

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

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

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

Abstract: The plate for extrusion, having discharge holes equipped with fitted inserts, in which the discharge holes each possess a seating having a circular base surface and an outlet opening at the surface of the plate having a substantially elliptical outline, the major axis of the ellipse being equal to the diameter of the base surface, an insert being fitted in the seating which possesses a base surface, facing towards the inside of the plate, having a substantially elliptical outline which can be inscribed, with slight clearance, inside the opening of the seating, and having an opposite surface, facing towards the outside of the plate, having a circular outline with its diameter equal to the minor axis of the base.

Abstract: A modular unscrewing injection mold and core assembly therefor includes a mold base, a core receiving opening extending through the mold base, the core assembly being removably mounted in the core receiving opening and including first and second core shells that may be secured together to receive a rotating core therebetween; a mold core rotatably mounted between the shells; a pinion gear formed on the mold core for being driven by a rack in the mold base, for rotating the mold core; the core assembly being releasably secured in the base.

Abstract: An apparatus for molding a cap (16) including a base portion (18) and peripheral skirt (20) extending axially from and about the base portion (18) includes an outer surface forming mold (44) for forming an outer surface of the base portion (18) and the peripheral skirt (20) and an inner surface forming mold (46) seatable within the outer surface forming mold (44) for forming an inner surface of the base portion (18) and the peripheral skirt (20). The outer surface forming mold (44) is retractable from seated engagement with inner surface forming mold (46) for exposing the molded cap (16) therebetween. The inner surface forming mold (46) includes a core portion (52) and lug forming mold portions (54) disposed radially peripherally thereabout, the lug forming mold portions (54) being able to project axially from and retract radially inwardly relative to the central core portions (52) for releasing and ejecting the molded cap (16) from the inner surface forming mold (46).

Abstract: A liquid tight connector for affixing, in a liquid tight manner, to a conduit having a ridge located adjacent to its end, wherein the conduit extends into a bore (5) and abuts against a sealing surface (6) and is held in liquid tight engagement therewith. A locking member (9) projects into the bore (5) and locks on to the ridge of the conduit.

Abstract: An elastomeric-covered shrouded impeller having a pair of disk-like shrouds enclosing vanes and vane passages which has an improved throat opening having sweeping internal sidewalls is disclosed. A three-piece mold core is utilized to form the vane passage and the sweeping curved throat inlet of the impeller.

Abstract: A cavity stripper which is positioned between two mold plates of a mold is used to remove a molded U-shaped article from a cup in one of the mold plates. The cavity stripper is movably attached to the mold plate that houses the cup. The cavity stripper is spring loaded such that it follows the moving mold plate for a short distance and by mechanical interference urges the molded article to remain with the mandrel during opening operations.

Abstract: A one-piece molded end closure has a pull ring spaced from a main panel having an annular flange extending therefrom. When the end closure is frangible through having score lines formed in the main panel, the pull ring is connected by a tenon adjacent a score point, which is the junction of two score lines and inside of the inner diameter of the pull ring, so that pulling on the pull ring, which is substantially parallel to the main panel, starts rupturing of the two score lines. The end closure also may be a plug type having a friction fit within a container whereby there are no score lines; the pull ring is still used to remove the end closure from the open end of the container. The method and apparatus for molding enable production of the end closure as one piece without any tearing of the pull ring or rupturing of the score lines when the end closure is removed from the molding apparatus.

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

Abstract: A male mold member includes a base or body having a central projecting core with an intermediate peripheral tapered seat between the core and body. The body, seat and core are intercepted by a plurality of cylindrical bores spaced uniformly about the male mold member and inclined toward the core axis. The bores receive core blades having cylindrical bodies. The core blades are exteriorly shaped in the area of the core to form sections which continue the contour of the core and seat. The blades may each have a thread matrix in the core area. After molding, a stripper bushing, engaging the molded product, pushes the product along with the core blades to a position at which the core blades are collapsed so that the product may be stripped. In the molding position the stripper bushing has a tapered bore opening which fits snugly against the tapered seat portions on the blades to orient the blades to proper position and immobilize them.

Abstract: An injection molded plastic article is produced by introducing a stream of molten plastic material from an injection molding machine cylinder into an article forming mold space. Pressurized gas is supplied into the interior of the molten plastic material to form a gas containing cavity therein. The plastic material is then allowed to solidify and cool sufficiently so that the article can itself sustain the form dictated by the mold surface. The cavity is vented to reduce the pressure within the cavity to ambient pressure prior to opening of the mold.

Abstract: A injection metal mold wherein a metal mold body having an article forming section therein and a metal mold fixing frame separately formed from the metal mold body, and on which the metal mold body is fixedly mounted and which is to be mounted on a molding machine body is constituted such that a slide mechanism section for a slide core which is moved into or out of the article forming section of the metal mold body in response to opening or closing movement of the metal mold body is provided on the side of the metal mold fixing frame. Further, a forming section of the slide core is formed as a separate member from the slide mechanism section and is removably mounted on the slide mechanism section.

Abstract: A collapsible core and molding apparatus and method for molding a plastic article having an undercut and a non-undercut portion. The collapsible core includes a center core pin and a core sleeve about the core pin and with the core pin having a small plurality of alternating, uniform, narrow, non-collapsing segments secured to the center pin and the same plurality of uniform, alternating, wider, arcuate, collapsing segments secured to the core sleeve, the wide collapsible segments adapted to move between the non-collapsed segments to form the expanded position for a molding operation where the wide segments are separated by the narrower segments, and a collapsed position where the collapsible segments collapse radially inward on the axial withdrawal of the center pin to form a generally cylindrical, cross section, arcuate area and to permit the ejection of a small molded plastic article from the mold.

Abstract: A sintering device includes separable mould walls which together define a mould cavity and a mould core which is positioned within the cavity to define an undercut mould surface. The core includes a hollow frusto-pyramidal central support formed with guideways and a plurality of core segments mounted for slidable movement within the guideways whereby the core is radially expandable and contractable. The segments include a plurality of arc-surface segments alternating with trapezoidal segments. The mould walls and the core include passages for introducing steam and air into the cavity. The passages of the core place the hollow interior of the central support in communication with the mould cavity.

Abstract: A self-lubricating metallic matrix for injection molding, the matrix having an element having a lubrication requiring sliding wall in which a plurality of receiving holes are formed in such a positional relationship that end faces thereof may be positioned in a partially overlapping relationship with each other in the direction of such sliding movement, and a solid lubricant received in the receiving holes of the element.

Abstract: A slide core mold for injection molding wherein a slider block provided in its front surface with an undercut core is slidably provided on the side of a core mold, a pressure receiving inclined surface provided with guide grooves in opposite sides being provided at the back thereof, projections fitted into said guide grooves are provided on opposite sides at a corresponding position of a cavity mold corresponding thereto, a block body formed in its front surface with a pressing inclined surface in contact with the pressure receiving inclined surface of the back of the slider block is projected, and the slider block is reciprocated in association with engagement and disengagement of the core mold and the cavity mold.