Abstract: A spiral bevel gear having right and left tooth flanks having such a small pitch angle that either right or left ones are not seen in plan from the apex side of cone is molded by a powder molding device so as not to interfere with a die of the device when removed from the die. The die has teeth for molding and is rotatably supported. A fixed guide mechanism for guiding the die is provided. Guide portions of the guide mechanism have a predetermined lead so that the die is rotated guided by the guide portions when the molded article is punched out of the die. Thus, the teeth formed on the molded article reliably disengage from the teeth for molding. This makes it possible to reliably punch the molded article out of the die.

Abstract: Apparatus and a method for injection molding large container lids of the type having threads for screwing the lids onto and off large containers. The apparatus includes an injection mold having a cavity mold portion and a core mold portion which together define the shape of the lid. The core mold portion includes a stationary annular ring that defines the lid threads. A co-axial, rotatable center section of the core mold portion is opened to spin the molded lid off the core mold portion and release it from the mold.

Abstract: A tamper-indicating closure of integrally molded plastic construction that includes a base wall having a peripheral skirt with internal threads for engaging external threads on the finish of a container. A tamper-indicating band is connected to the lower or free edge of the skirt by a plurality of circumferentially spaced integral bridges. At least one of the bridges has a greater circumferential dimension than other of the bridges. A thin integral membrane is disposed in the band immediately circumferentially adjacent to the one bridge, and extends both axially and circumferentially of the band. A stop flange is positioned on the band for engaging a bead on a container to inhibit removal of the closure, such that the membrane and the other bridges rupture upon removal of the closure but the band remains connected to the closure by the one bridge of enlarged circumferential dimension.

Abstract: An innovative container lid having an integrally formed tamper evident band that goes through a series of changes or metamorphoses during the manufacturing and application process. The tamper evident band is attached to the lid at weak points on dogs formed around the periphery of the lid. Before use, the tamper evident band has a diameter substantially larger than the outer diameter of the lid. When the lid is installed in a container, and tangential and radial forces are applied to the periphery of the lid, the attachment points of the tamper evident band rupture and the band is displaced in a rippling effect with the dogs locking into sockets formed in the sidewall of the tamper evident band. Continued pressure is applied to the side of the tamper evident band until it is pressed firmly around the entire periphery of the lid against the side of a container with all the dogs engaged in sockets.

Abstract: A molded closure for use with a container includes a top wall defining a generally planar inner surface and a skirt depending from the top wall generally perpendicular thereto. The skirt includes a container engaging member formed therein. The closure includes a retaining projection formed in the top wall contiguous with the inner surface and extending therefrom inwardly of the closure. The projection extends from the surface perpendicular thereto and defines at least a pair of mold binding surfaces perpendicular to the top wall surface. The binding surfaces are formed in facing relation to one another. The closure is formed in a heated state, and as the closure cools, at least the binding surfaces exert a binding force on the mold block at a location forming a part of the projection to momentarily retain the closure bound to the molding apparatus.

Abstract: An injection molding apparatus and method of injection 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: An apparatus for creating freestanding columns of compressible substances such as snow and sand. These freestanding columns can then be sculpted into any desired shape. The apparatus is placed on level ground, filled with the compressible substance after which the substance is compressed using hands or other implements. The operator then rotates the apparatus by pushing horizontally on the handles, thereby causing the apparatus to rise vertically due to the spiral grooves on the inside surface of the apparatus. As the apparatus rises vertically, the column of compressed substance remains stationary while creating space at the top of the apparatus for the addition of more of the compressible substance. The process is repeated until desired height is reached.

Abstract: A method uses a mold for making a bracket of a brake lever device. The mold includes a mold cavity and a stem and a block extended inward of the mold cavity for forming the aperture and the orifice of a band of the bracket. A material is then injected into the mold cavity for forming a prototype of the bracket. The prototype is tapped for forming an inner thread in the aperture of the band, and is cut for forming the slot and the ear and for forming a C-shaped structure for the band. The ear has an oblong recess for engaging with a head of a fastener.

Abstract: An annealing mold and fiber retaining device includes a fiber holding plate having fiber channels and an annealing insert. Retainers are provided for attachment to the plate to retain fibers in the channels. After annealing, the annealing insert is replaced by a packaging insert. The fiber holding plate is mounted between a support plate and a cover plate. The mounted plates include a coextensive current conductor port and the plates are mounted in a housing which includes vibration mounts for isolating the plates from vibration within the housing.

Abstract: A process of 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 method of injection molding a container having a body and an upper opening surrounding a neck of a container produces a container in which a diameter of the body is greater than the diameter of the neck. The method includes injecting plastic or other appropriate material into a cavity of the mold assembly and, after the container material has cooled sufficiently to retain its shape, sequentially removing portions of the mold assembly from the container.

Abstract: A staged, sequentially separated injection molding apparatus for forming a molded container closure includes a mold base portion, a plurality of concentric, separable telescopic mold elements, and an opening therein defined by one of the base portion and the mold elements for injecting a mold material into the apparatus. The elements are configured such that they can be separated or removed from the mold, from the inner most element outward, to provide sufficient free space for the newly molded part to flex inward as the mold elements are removed. The inward flexing of the part, permits ready removal of the next outwardly most mold element, while minimizing the possibility of damage to the molded part. Each of the mold elements includes a mold face, which in conjunction with the base portion, in part defines a mold cavity. The inner and outer mold elements and the intermediate mold element include flange portions opposite of their respective mold faces.

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 means 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. A process for forming a threaded, molded plastic article is disclosed including molding the article in an injection mold and removing the article from the mold by rotating a rotatable and movable unscrewing means to rotate and remove the article from the mold core.

Abstract: A method of manufacturing the cylindrical product includes the steps of inserting a first cylindrical mold into a hole at the center of a second cylindrical mold and engaging a toothed portion on the first cylindrical mold with a spiral groove on the second cylindrical mold to provide a lower mold. Further, an upper mold is mounted thereon to form a space for forming the cylindrical product and molten resin material is injected into the space to harden therein. The second cylindrical mold is withdrawn in a direction to allow the mold to be opened, the first cylindrical mold is axially moved to insert the toothed portion into a relief groove on a flat portion of the second cylindrical mold, the first cylindrical mold is rotated in a direction to withdraw it along the flat portion, the upper mold is rotated to extract the cylindrical product.

Abstract: A molding die assembly includes an outer molding die which forms an outer peripheral surface of a cylindrical mold, and, an inner molding die which forms an inner peripheral surface of the cylindrical mold, wherein the outer molding die is comprised of a plurality of split die elements which are split at an oblique separating surface inclined with respect to the circumferential and axial directions of the cylindrical mold.

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 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: 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: 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 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: 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: 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 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: 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: A compact core and ejector assembly includes an elongate core terminating in a male mold component and including a cylindrical shoulder which supports the top plate of an associated core support frame. The shoulder includes opposing, longitudinally-extending slots which receive jaw elements, which are pivotally mounted on a reciprocating knock out plate, and therefore guide the jaw elements during the ejection procedure. The top plate, knock out plate and core plate are cut away so that rows of cores may be arranged in a densely packed configuration. In a preferred embodiment, the lateral sides of the top, knock out and core plates have a cut away or sinusoidal shape so that abutting rows fit in an overlapping relationship.

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: 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: A tamper indicating package comprising a container having a neck with a threaded finish, an annular bead on the neck, a plastic closure which includes a base wall and a depending peripheral skirt having threads interengaging the threads of the container, and a tamper indicating band attached to the skirt by a plurality of weakened portions defining a line of severing. An annular flange extends axially upwardly and inwardly from the tamper indicating band toward the base wall of the closure and comprises a first continuous annular flange portion connected to the band by a hinge portion and a second portion which has free ends of the segment portions engaging beneath the bead on the container when the closure is threaded onto the container. In one form the second portion comprises a plurality of segment portions extending upwardly and inwardly from the first continuous portion. In another form, the second portion comprises a second continuous flange portion.

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: 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: 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: An apparatus for casting polymer threads (32) in a nut cavity (14) complementary to the threads (44) of a casting screw (42) to minimize the formation of air pockets and air bubbles in the polymer threads. The cavity (14) of the nut (12) has a diameter larger than the diameter of the casting screw (42). The threads (32) of the nut (12) are formed in a polymer (30) which is dispensed into the nut cavity (14) and which cures around the threads (44) of the casting screw (42) after the screw is inserted into the cavity of the nut. The nut casting apparatus (10) includes support member (54) for closing the bottom of the cavity (14), and for containing the polymer (30) therein.

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

Abstract: A coupling apparatus and method is disclosed for coupling a first hose for enabling the flow of a fluid therethrough, comprising a first coupling member having a first coupling internal bore extending between an inner end and an outer end. First coupling threads are defined in the first coupling member proximate the inner end whereas first coupling linking threads are defined by the first coupling internal bore of the first coupling member proximate the outer end. A second coupling member has second coupling threads defined therein. A first attachment member has first attachment linking threads with means for affixing the first hose attachment member to the first hose. The first attachment linking threads are engagable with the first coupling linking threads for securing the first hose to the first coupling means. The first coupling threads are engagable with the second coupling threads for interconnecting the first coupling member and the second coupling member for coupling the first hose thereto.

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 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 self-draining container and method of forming. The container includes a body and a wall extending upwardly from a body opening. The wall surrounds a dispensing spout which extends above the top of the wall. A web joins the wall and the dispensing spout to form a drain channel. A drain opening is defined adjacent the channel for draining fluid from the channel into the container body. A cap having a depending skirt defining a thread which mates with an internal thread on the container wall to close the container.

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 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: This cluster of moulded gears with the helical teeth, comprising a group of coaxial pinions of which the teeth have the same helical sense and the same pitch, is characterized in that, Mrn and Mri designating the real moduli of any pinions respectively of rank n and of rank i of the group, Zn and Zi designating the numbers of teeth of the said pinions, and .beta.n and .beta.i designating their helical angles, the following relationship exists between these different parameters:sin .beta.n=sin .beta.

Abstract: One of two mold halves to be clamped is composed of an insert holder, an insert mounted detachably on the insert holder, and a rotary core supported rotatably by the insert and having a threaded portion formed on an outer peripheral surface thereof. When clamping is effected, the rotary core is caused to project into a cavity formed in the other mold half, and moldings are injection molded inside the cavity around the rotary core. The insert holder is provided with a driving source such as a motor-driven gear, while the insert is provided with a rotation transmitting mechanism composed of such as gears for rotating the rotary core. If the insert is mounted in the insert holder, the driving source provided in the insert holder is coupled with the rotation driving mechanism provided in the insert, rotating the rotary core and making it possible to remove the moldings having a thread formed on an inner surface thereof from the rotary core by rotating the rotary core.

Abstract: A die casting apparatus for casting an article with an internally screw-threaded bore. The die casting apparatus includes a support, a die assembly coupled to the support, a core pin with external threads which are movable into and out of the die assembly, a lead screw for moving the core pin, a fixed bushing threadedly receiving the lead screw therein, a drive assembly, and a control assembly. The drive assembly has a hydraulic motor with an ouptut shaft that is axially arranged relative to the core pin for smoothly driving the core pin and lead screw. The external threads of the core pin and the external thread of the lead screw are identical for driving the core pin and the lead screw at the same rate to avoid damaging the newly formed internal threads of the cast article.

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: 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 plurality of rotational members which comprise an inner shell and an outer shell rotatable relative to each other and in which a soluble film is fixed to the inner periphery or the outer periphery of one of the shells, the shell with the soluble film fixed thereto is the shaping mold of a molding machine for molding the other shell, and a plurality of rotational members comprising an inner shell and an outer shell are molded through the soluble film, whereafter the soluble film is dissolved and removed.

Abstract: A mold for forming a plastic closure includes a first mold part defining a female cavity and a second mold part defining a male mold cavity surface, with the second mold part including a core having a knock-out pin reciprocated therein and surrounded by a fixed sleeve which cooperate to define a tamper-evident band on the cavity for the closure. Vents are provided for venting the lower edge of the cavity during the ejection-molding process. Also, the knock-out pin has a lubricant pocket formed on the peripheral surface thereof.

Abstract: A die member for forming a foam pattern for casting a cylinder block in a lost foam casting process, the pattern having a cylindrical bore with an axis, and a helical transfer passage including a first portion permitting die member separation in a direction along the axis of the cylindrical bore and an undercut portion preventing one-piece die member separation in the direction along the axis of the cylindrical bore, the die member comprising a main portion forming at least a portion of the cylindrical bore and including a projection forming a first part of the first portion of the transfer passage, and a core carried by the main portion and movable relative to the main portion along a line in a plane substantially perpendicular to the axis of the cylindrical bore, the core being movable between an extended position in which the core forms a second part of the first portion of the transfer passage and the undercut portion of the transfer passage, and a retracted position in which the core affords separation o