Abstract: A method of manufacturing a rubber or plastic-coated roller such as a fixing roller to be used in the thermal fixing part of an electrophotographic copying machine.

Abstract: An apparatus to encapsulate a device and joints coupled to conductive leads with an encapsulating material. A fixture has a recess to hold via a vacuum the device in place. Conduits in the fixture supply air around the device to form an air dam that flows outward around the device and the leads. A nozzle supplies a metered amount of material to the surface of the device. By controlling the temperature of the fixture and/or the air forming the air dam, the flow of material can be confined to the surface of the device and the joints as it cures. The method can also provide encapsulant edge capping to reduce device stresses.

Abstract: A method of integrally molding a member to be molded onto a portion of a rigid member, which method is applied to manufacture of a connecting rod used in a crank device of a wiper system in a motor vehicle, for example. In this method of molding, a portion to be positioned is formed in the rigid member, a portion of the rigid member is inserted into a cavity for molding the member to be molded in such a manner that the portion to be positioned is exposed in the cavity, positioning members linearly movably provided in this cavity are engaged with this portion to be positioned to effect positioning, the positioning members are retracted to the outside of the portion to be positioned after the positioning, and thereafter, a molding material is poured into the cavity to mold the member to be molded.

Abstract: The invention relates to a device for producing and positioning a label on a thermoformed container. The device includes, inside a thermoforming station including a molding unit, at least one row of upwardly open forming chambers, a vertically movable supporting table supporting the molding unit, an individual band of labels for every forming chamber, means for at least partially cutting the labels in order to detach them from their individual band, a storage roll of master band mounted in fixed bearings, a cutting unit for cutting the master band longitudinally, a supporting table on which is installed the longitudinal cutting unit, and a tension roller applied against the master band.

Abstract: The invention relates to a lens mounting (11) for an electrodynamic device for recording and/or reading information in and/or from optically readable discs, which device comprises a frame with supporting means for guiding the lens mounting. The lens mounting comprises a first part (27) which cooperates with said supporting means and a second part (31) which is movable relative to said first part and which comprises the mount (32) for a lens system for focusing a radiation beam. The lens mounting (11) further comprises connecting means (33A, 33B and 35) which movably connect the first and the second part to each other. Respective opposite ends of the connecting means are embedded in the first part and the second part of the lens mounting by injection molding into a molding which is configured so that the relative position of the first and second parts are defined by the corresponding portions of one molding die.

Abstract: Apparatus for molding a composite metal-elastomer styled wheel in which a middle mold part consists of a metal wheel disc and rim subassembly. A base mold part seats against the outboard face of the metal wheel in the closed condition of the mold and has a mold cavity surface to provide an ornamental configuration for the outboard face of the plastic body of the composite wheel. A clamp seats against the inboard face of the middle mold part to urge the middle part into sealing engagement with the base mold part. The mold parts are axially separable from one another to open the molding apparatus to clear the middle mold part from said clamp and base mold parts. The clamp includes a funnel adapted for registry with a liquid reaction mixture injection nozzle coupled with injecting mixing apparatus. The funnel has a nozzle passage registering with a pour opening in the disc in the closed condition of the mold.

Abstract: The present invention relates to a machine for molding objects, having male and female mold parts of which at least one is mobile with respect to the other. According to the invention there is included a device for conveying film and a device for conveying a molded object capable of moving in synchronism so that, when the film conveying device is in position of depositing the film between the mold parts, the object conveying device is in position of removal of the object from between the mold parts, and, when the film conveying device is in position of taking of a film for use in a further cycle, the molded object conveying device is in position of evacuation of the object from the mold.

Abstract: This invention relates to a device for positioning a film of determined format, serving as at least a partial coating of the lateral surface of an object, between two pieces of a machine, at least one of said pieces being mobile with respect to the other in a first direction, the machine having a technique for taking the film from a magazine. According to the invention, the film-taking technique uses a member whose outside shape corresponds to the lateral surface of the object to be coated. It also includes a technique for applying the film onto the lateral surface. Further there is provided a technique for conveying the film-taking means, with the film applied on said member, between a position of taking the film from the magazine and a work position between the pieces of the machine.

Abstract: This invention relates to a device for transporting a film of determined format from a position where a film is taken from a magazine to a work position between two parts, mobile with respect to each other in a first direction, of a machine. The device includes apparatus for taking a film from said magazine capable of moving, in a movement asociated with that of said parts, in a second direction at right angles to said first direction between said position of taking and said work position, and drive apparatus are associated with said magazine to animate the latter, independently of said parts but in synchronism therewith, by a reciprocating movement parallel to said first direction.

Abstract: A staged mold for stabilizing hazardous wastes for final disposal by molding an agglomerate of the hazardous wastes and encapsulating the agglomerate. Three stages are employed in the process. In the first stage, a first mold body is positioned on a first mold base, a mixture of the hazardous wastes and a thermosetting plastic is loaded into the mold, the mixture is mechanically compressed, heat is applied to cure the mixture to form a rigid agglomerate, and the first mold body is removed leaving the agglomerate sitting on the first mold base. In the second stage, a clamshell second mold body is positioned around the agglomerate and the first mold base, a powdered thermoplastic resin is poured on top of the agglomerate and in the gap between the sides of the agglomerate and the second mold body, the thermoplastic is compressed, heat is applied to melt the thermoplastic, and the plastic is cooled jacketing the agglomerate on the top and sides.

Abstract: The present invention is directed to an apparatus for the production of back-foamed covers from cover materials and foam comprising(i) a mold comprising an upper mold half and a lower mold half, the lower mold half having a cavity therein, the inside surface of which is capable of being covered by the cover material,(ii) a mixhead associated with the mold, the mixhead capable of introducing foam materials and/or reactants into the mold cavity,(iii) a pusher bar arranged on a mount for pushing the cover material into the mold cavity and being arranged above the lower mold half, the pusher bar being constructed such that when the bar is pushing the cover material into the mold cavity, a gap is formed between the edge of the mold cavity and the edge of the pusher bar, the gap being less than the thickness of the cover material,(iv) the lower mold half being movable towards and/or away from the pusher bar, and(v) the surface of the pusher bar facing the mold cavity edge being a frictional surface.

Abstract: An apparatus for making composite plastic product includes a mold insert with locating boss formations preformed from high strength plastic having openings formed therethrough; and wherein the insert is configured to be located on a mold cover which carries a locking device to hold the insert in place and wherein the locking device includes automatically operated knock-out means that engage the boss to separate a molded part from the lid when the locking device is released.

Abstract: The tubular body is laid in a horizontal position on a tapered suction drum and pivoted thereby into a vertical axis which is in coaxial relationship with the axis of a mandrel with a punch. The tubular body is then pushed from the surface of the suction drum on to the mandrel by a thrust member. The mandrel and/or the die is mounted displaceably in a vertical direction, which permits particularly stable and precise guidance. A plurality of dies with mandrels and punches associated therewith is disposed on a rotary member. In the course of a revolution of the rotary member, the tubular body on the mandrel is connected to a squeeze moulding in the die.

Abstract: A method for centrifugally casting a rectangular access floor panel includes the steps of forming a metal pan having a planar bottom, peripheral sidewalls and a plurality of upstanding tabs, inserting the metal pan into a cavity defined by a two-part mold and filling the pan within the mold with a concrete mixture. The mold is rotated about a vertical axis and vibrated to evenly distribute the concrete mixture within the pan. A smooth magnetic sheet is placed within the cavity. The sheet engages the planar bottom of the metal pan and prevents seepage of the concrete mixture through openings in the bottom of the pan during casting. The apparatus includes a turntable, a drive for rotating the turntable and a mold clamped to the turntable. The mold is vibrated during rotation to insure a void-free distribution of the mixture throughout the pan.

Abstract: A machine and method for manufacturing a disposable absorbent continence pad. The machine has a series of stations including a shell-forming station for forming a shell from thermoplastic material, a slitting station for forming slits in a facing material to be sealed to a shell in order to permit the facing material to adapt to the shape of the shell and a sealing station where the facing material and the shell are heat sealed together. The shell-forming station, slitting station and sealing station have special components to assure accurate molding of the shell and prevent wrinkles in the facing material. The manufacturing method embodies a series of processing steps as carried out at the aforesaid stations.

Abstract: Molds for making composite bodies having at least three sections which are united along generally aligned intersections wherein the molds include two slideable molding blocks having molding cavities therein which are movably oriented with respect to a stationary molding cavity and wherein separate injectors are utilized to fill each of the cavities depending upon the positioning of such cavities.

Abstract: A system is provided for bringing a film, forming at least a partial coating of a molded object, into a mold. In this system, the transport device includes means for holding the film in position during transport thereof from the waiting position to the working position, and two cooperating members, of the rack or screw type, meshing with each other, the first of which is parallel to the direction of movement of the movable part of the mold and is fixed to one of the parts thereof and the second of which is secured to the means for holding the film in position and may slide in the movable part of the mold.

Abstract: A method and apparatus are disclosed for quickly and exactly locating a desired structure in a specimen or the like located on a plate or slide, and then preparing an accurate, embedded specimen block for later use, and particularly for preparing thin sections, e.g., 0.1 microns or less, on a microtome machine, for microscopic examination.

Abstract: An apparatus for centrifugally casting a rectangular access floor panel includes a turntable, a drive for rotating the turntable about a generally vertical axis in a generally horizontal plane, and a mold clamped to the turntable. The mold is vibrated during rotation to insure void-free distribution of a lightweight concrete mixture throughout a metal pan retained within the mold. A hopper and an auger feed the concrete mixture to the mold through a sprue. The mold retains corner pads and silencer buttons. The corner pads cooperate with pedestal heads to eliminate the need for stringers.

Abstract: Injection or transfer molding of plastic is performed in a manner that virtually eliminates flash. Deflection of the mold press is measured with the mold press in a clamping configuration. Then the support structure of the molds is arranged to apply an equal force to the mold face by configuring supporting pillars and bars such that they act as individual springs. Their spring constants and/or lengths are calculated to account for the actual deflection found in the mold press, thereby, producing a uniform pressure on the molds during clamping of the press.

Abstract: A lens is produced having one aspherical surface which is accurately axially aligned with a spherical or flat surface on the opposite side of the lens. The aspherical surface is produced with a mold. The mold has a molding surface having an accurate negative profile and the desired finish of the required aspherical surface.The mold is on a rotatable jig. By means of adjustment screws the mold is adjusted to correct misalignment of the axis of the molding surface and the axis of rotation of the jig. Misalignment is detected by directing a collimated light beam onto the molding surface so that it is reflected onto a screen. When the mold is rotated, the light beam moves on the screen until the molding surface is properly aligned with the axis of rotation.A preformed glass substrate has one aspherical surface of approximately the desired profile and finish and on its opposite side a spherical or flat surface.

Abstract: The disclosure is directed to an encapsulation molding apparatus to be used for subjecting small-sized electrical elements to encapsulation molding by a synthetic resin material. The present invention has been presented for the purpose of shortening the cycle time required for the encapsulation molding, and also, reducing cost necessary for molding metal molds, and installation cost for a molding press, etc., with a simultaneous reduction of a loss in the synthetic resin material. More specifically, in the apparatus of the present invention, for subjecting small-sized electrical elements to encapsulation molding by the synthetic resin material, pots (30) for charging the synthetic material thereinto are provided at preferably equal intervals with respect to a plurality of cavities provided in an upper mold (11) and a lower mold (12) for the formation of encapsulation molded portions, while extruding plungers (31) are provided for the respective pots for effecting the encapsulation molding.

Abstract: A multipart mold assembly for removably receiving a casing unit and positioning the casing so as to form, in combination with at least one of the mold parts, a cavity having the shape of an element to be formed in the mold and bonded to the casing. One mold part has a surface defining part of the shape of said cavity, and a casing skirt support surface forms another part of the cavity. A flash barrier is formed along a part of the skirt casing when a clamping ring formed from a plurality of individual clamping ring elements engages the surface of said casing skirt and urges it into fluid-tight relation with the casing support surface.

Abstract: The invention comprises a method and various apparatus related to fabricating solid particulate filter bodies and other honeycomb structures the cells of which are selectively charged with a plugging or other flowable material. Solid coverings are applied over the end faces of a honeycomb structure, preferably an adhesive backed transparent thermoplastic film such as polyester, openings are created through the covering, preferably by melting the thermoplastic film, and the sealing or other flowable material is charged through the openings formed in the covering into the underlying cells.A porous walled honeycomb structure having coverings adhered to its end faces with selective openings therethrough is itself a solid particulate filter of some usage. A more substantial solid particulate filter body may be formed by charging a more durable sealant through the openings to form plugs and removing the coverings.

Abstract: The label transferring device for placing labels in a separable mold of a blow molding machine which includes a pair of movable platens which converge the mold portions and also move in unison to different blow molding stations of the machine. An articulating arm is mounted directly on one of the platens and includes a vacuum section head to transport the labels. The articulating arm moves the carrying head from a label supply magazine which is also mounted on the platen to a labeling position between the molds, so that both the articulating arm and supply magazine are carried by the platen as it moves to different blow molding stations. Preferably, an articulating arm having a plurality of carrying heads is mounted on each platen along with a label supply magazine.

Abstract: A pre-shaped aluminum plate is held against the flat end wall of an inverted mold cavity by vacuum pressure communicated through bore holes in the wall leading to a vacuum chamber in the mold body. A high temperature PTFE gasket shaped to match the plate fits in an annular recess in the wall to provide a seal between the wall and plate. Polyurethane foam expands and hardens in the mold cavity to further press the plate against the wall and to form a foamed plastic water ski having a flush aluminum deck. The mold cavity has a curved side wall to produce a ski having a radiused edge about the deck.

Abstract: A blank is formed out of plasticizable, heated plastic by means of an extruding-type material supply head. A somewhat lenticular profiling of the blank is obtained by appropriately controlling a closing member of the material supply head, which is built as a valve cone. When the closing member is closed off against the lower edge of a tube part of the material supply head, the blank is pinched off from the material supply. A flow of air emerging from the ring nozzle serves to ensure complete severance of the blank from the material supply head. After that has been accomplished, the blank enters an open shaping cavity of a die by free fall. By further movement of the die, which is located on a rotary table, the die removes itself from the permanently located material supply head, so that the blank lying in the cavity can be pressed into a molded article by a stamp. Cooling off too much in certain locations on the blank is prevented by the free fall of the blank into the shaping cavity.

Abstract: Apparatus for enclosing semiconductors with resin by molding, including a stationary upper mold having a plurality of pots, and a movable lower mold opposed thereto.The upper and lower molds have cavities to which a resin material supplied to the pots is pressingly injected directly or only through gates.Disposed at the upper mold side is a resin material pressurizing mechanism having plungers fittable into the pots, and one or more cylinders and piston rods for actuating the plungers.

Abstract: A headpiece for a collapsible tube is a unitary member made up of two different plastics, each plastic providing a different property for the headpiece. The headpiece is formed by extruding on top of one another a first torus like annulus of a first plastic and a second torus like annulus of a second plastic. The two plastic annuli are simultaneously molded to form the headpiece. One plastic forms, primarily, the outer portion of the headpiece and the other plastic forms, primarily, the inner portion of the headpiece.The machine for molding the plastic head includes a work table rotatably indexed from station to station at which various operations are performed. The mandrel which holds the cylindrical body, to which the head is molded, is movable from an inboard position to an outboard position so that operations can be performed relative to it. The molding operation is performed at the inboard position. The loading, extruding, capping and ejection operations are performed at the outboard position.

Abstract: A molding method and apparatus in which an insert part is supported in a mold cavity by a pin. The pin is withdrawn when the resin pressure in the mold exceeds a predetermined value.

Abstract: This relates to the mounting of a mold for movement between a forming poson wherein a cup or container is formed therein with there being simultaneously applied to the formed cup a label, and a remote position wherein the mold receives a label. In the normal operation of the mold it is necessary that the mold be first moved axially to clear the newly formed cup and then pivoted to one side to a label receiving position for receiving the label. This particularly relates to the return movement of the mold from the label receiving position to the forming position wherein the movement is effected in a single step with the movement being a compound movement instead of the straight line movement followed by a pivotal movement of the mold as it moves from the forming position to the label receiving position thereby eliminating one separate movement step and thereby greatly reducing the time required to effect movement of the mold from the label receiving position to the operating position.

Abstract: Blocks with a casing composed of upper and lower parts are produced by inserting the upper and lower parts in an inserting device above and below pushing elements between upper and lower pressing dies of a press, displacing by the pushing elements the lower part in a chamber of a mold towards the lower pressing die and the upper part towards the upper pressing die with self-releasable holding on the latter, withdrawing the inserting device from a pressing region between the upper and lower pressing dies, and cyclically repeating these steps in synchronism with a working stroke of the press.

Abstract: A cathode structure for a sodium sulphur cell is formed by putting a fibre matrix into a mould which is closed to shape the matrix to the required form with compression of the fibrous material, the mould being kept at a temperature below 12.degree. C. and preferably between 8.degree. and 10.degree. C. while liquid sulphur is injected into the compressed fibre material.

Abstract: In a process for making a filled and closed container of heat-sealable plastic hose, in one work operation, the hose is expanded to become a container body, the body is filled and the upper part of the container is shaped when the container is closed. After the filling process and before closing, the upper part of the container is closed by a rubber stopper. An apparatus to carry out the process includes a container-molding appliance having a lower and upper mold parts, with a mold holding fixture in each of the upper parts which can be displaced in the direction of movement of the upper mold part and be moved automatically opposite the upper mold part, and with a holding device inside the plastic hose which can be moved vertically. The holding device releasably holds the rubber stopper for insertion into the completed container body.

Abstract: An elongated mold box encloses a removable rectangular pallet and has a center portion pivotally supported by a carriage which is supported for vertical movement by a pair of vertical guide posts mounted on a frame. Hydraulic cylinders are connected to move the carriage vertically relative to the frame and pivot the mold box relative to the carriage for tilting the mold box between a vertical concrete filling position and a horizontal position for stripping a molded concrete article from the mold box. The pallet is supported within the mold box by a generally flat tray member which is guided by parallel rails within the mold box and aligned horizontal guide rails on a run-out platform. The mold box also carries a hydraulic cylinder for moving the tray member between a retracted position within the mold box and an extended position on the run-out platform.

Abstract: A method and apparatus for forming a loosely felted mat of elongated wood flakes mixed with a binder, the mat including a longitudinal axis and the wood flakes being aligned in mutually parallel relation and parallel to the longitudinal axis of the mat. The wood flakes are held in alignment in the mat by a plurality of closely spaced thin planar baffles, the baffles being comprised of a material which can form an integral part of the mat.

Abstract: A method and apparatus is provided for making a composite structural homogeneous resinous article having (a) a smooth, shiny non-cellular or homogeneous relatively thin injection compression molded liner on the outer surface and (b) a cellular relatively thicker injection molded core integral with the molded liner. One extruder is connected by valve controlled passages to a pair of injection devices, each device having an injection chamber. One chamber stores the homogeneous plastic resin and the other chamber stores the foam plastic resin. A first mold assembly having a movable upper mold part and a stationary lower mold part form a cavity, with a gap opening, at a first molding station. The cavity is in communication with the first injection chamber.

Abstract: An apparatus for automatically making egg rolls comprises an intermittently moving transmitting device and a plurality of forming assemblies on the transmitting device. Each forming assembly includes folding devices for folding three side portions of an egg roll dough and a mold device for receiving a part of the egg roll dough and an egg roll stuffing therein. The apparatus further comprises a device for feeding the egg roll dough successively on each forming assembly, a device for supplying the egg roll stuffing on the egg roll dough, a device for actuating the folding means of the forming assembly to fold three side portions of the egg roll dough over the stuffing in the mold device to thereby form a partially folded egg roll, and a device for wrapping the partially folded egg roll to form a cylindrical egg roll product.

Abstract: For over-molding a thermo-plastic material on a connector, the connector is, at the outlet of the machine having crimped the connector on a conductor, carried into a gripper maintaining the connector when introducting a core mounted on a conveyor. The connector is then carried into an injection mold from which it is extracted before complete cooling, to be carried to a cooling station comprising a mold similar to that of the injection mold but being at a lower temperature.

Abstract: A device for moulding bricks comprising a press to form blanks, moulding trays and projecting means formed by a carrier surface for inverting a blank by moving it along a circular path and for projecting it into a moulding tray wherein the carrier surface is guided in a manner such that it performs a pivotal movement during the movement along the last part of the circular path.

Abstract: An end capping machine is disclosed wherein a plastic end cap is formed and bonded to a cardboard sleeve so as to form an integral, wide-mouth container. Each cap is formed and thermoplastically bonded in essentially one-station of a multi-station operation. The machine of the present invention is particularly useful in forming oil cans, and eliminates the need for the conventional metal base and sides.

Abstract: Apparatus for forming, in two steps, panel, or shaped article, by first providing a bath of fluent cementitious material under a core of cellular, preexpanded and cohered polystyrene cells or pearls, having a density less than that of the cementitious material, allowing the core partially immersed to rise in a controlled way over the cementitious material, maintaining the core under pressure until the bath has partially set to prevent further rise of the core, pouring onto the core and partially set bath, a second quantity of fluent cementitious material to completely enrobe the core and form thereover a top revetment, smoothing the surface of the second quantity of cementitious material and letting it set to complete the panel.

Abstract: A mold for embedding a tubular member within a casing wherein the mold compensates for variations in length of the tubular member. The mold is a two-member structure wherein one of the members is provided with a cavity for receiving the tubular member and the casing. The cavity is closed at one end by a movable ring insert which moves relative to the assembled relationship of the tubular member within the casing to compensate for any length variations.

Abstract: A mobile brick molding machine includes a rectangular frame with a mold therein, the mold being a grid with open top and bottom ends for receiving a brick-forming composition when resting on the ground. The frame is provided with a wheel at its front center and a pair of wheels at the rear end thereof. The front wheel supports a jack, which is connected by a cable to a lever supporting one of the rear wheels whereby raising of the front end of the frame and mold using the jack results in virtually simultaneous upward movement of the rear end of the frame leaving the molded bricks.

Abstract: A process for moulding a food product consisting of a plastic mass, such as ice cream, and firm elements, such as biscuits. A multiple-cavity mould open downwards is placed on a fixed platform, a base is arranged in the mould on a vertically displaceable support, the biscuits are arranged between the base and the cavities and the mould is fitted with ice cream while the base is lowered.

Abstract: The present invention relates to a device for setting a base cup in a blow mold, comprising a pair of divided molds disposed on a machine base and transversely movable for opening and closing and a bottom mold disposed at the bottom of these divided molds; further comprising a horizontal stationary plate secured to the machine base, a carrier capable of reciprocal movement on said stationary plate, and a base body of said bottom mold vertically movably disposed on said carrier, said stationary plate being disposed so as to move beyond the machine base for displacing said bottom mold and said carrier from the center of said blow mold to the outside of said machine base, guiding members being disposed at necessary positions in a drive device for displacing said carrier, said carrier having members for vertically moving said bottom mold at the bottom of said divided molds, a base body being disposed in association with a lifting device, and said carrier and said drive device comprising a transfer device by being

Abstract: A first movable mold with both a runner and a core type mold is moved toward a stationary mold, and simultaneously a second movable mold supporting a motor bracket of plate metal is moved toward the stationary and first movable mold until all the molds engage one other to form around the core type mold a predetermined space to which the bracket is exposed a molten resin is poured into the space through the runner to mold a gear box integral with the bracket.

Abstract: This provides a way of producing a sand mould which does not require heavy echanical presses or violent vibration to ensure sand properly fills tight patterns in a mould. Sand is put into a buffer zone 40 via a feed device 2,3. Below the buffer zone 40 is a flask 10 and pattern plate 14, and the space between the buffer zone 40, the flask 10 and the plate 14 defines a charging chamber through which the sand must fall to produce the mould. This space, and preferably the buffer zone as well, is evacuated. This eliminates air resistance to the falling sand and, as a result, the sand fills the mould properly. The sand is allowed to fall after the vacuum has been established. The reason for evacuating the buffer zone is to bleed the sand of air. It is preferred that the pressure in the charging chamber is reduced further than that in the buffer zone, since a difference in pressure will further accelerate the sand towards the pattern plate.

Abstract: An injection casting apparatus for the manufacture of multiple layer shoe soles in a multiple element mold (11). The bottom of each mold is closed by one of two bottom stamps (14, 15) disposed on the ends of support arms (23, 24) which are mounted about an inclined axis of rotation (42). The bottom stamp not in use is directed radially outward from the apparatus to improve servicing and cleaning. The bottom stamp in use is centered above a raising and lowering device (37) which moves the stamp into operating position to close the mold and away therefrom to rotate the stamps. This centered arrangement prevents any torque from arising in the bottom stamp during use.

Abstract: A composite ski is made by bonding a metal ski top to a molded ski body during the molding and curing of the body. The ski body is placed in the mold cavity of a two-part mold, and the metal top is movably supported on the other mold part. One end of the metal top is held by a spring-biased holding pin which permits the metal top to expand and contract relative to the mold part as the mold is heated and cooled while maintaining the metal top in alignment with the cavity.