Abstract: A blow molding machine is disclosed for hollow plastic articles. The machine includes a clamp mechanism for a pair of mold sections. It comprises a body disposed below an extruder at an extruding station and a blow pin at a blow station and carrying opposed platens for supporting the mold sections. Each of a pair of levers is pivotally coupled with a respective platen and with the body and the levers are connected together by a pull bar. An actuating means displaces one of the platens relative to the body and equal and opposite motion is transmitted through the levers and the pull bar to the other platen for opening and closing the clamp. A lifting mechanism supports the clamp for movement between the extruding station and the blow station. The lifting mechanism is adapted for vertical motion by a hydraulic motor acting on a lifting frame. The frame is mounted by pivot links on the machine base and pairs of links are connected by a shaft with a crank arm, the crank arms being connected together by a tie rod.

Abstract: A plastic resin blow molding machine to form bottles from a thermoplastic resin forms a tubular parison of plastic resin by extruding the molded plastic from the circular orifice formed between a vertically aligned mandrel and a forming die. The mandrel is vertically adjusted relative to the forming die by an adjustment nut having screw threads which mate with the screw threads of the mandrel. The adjustment nut is rotatably mounted on a plate and is fixed to a ratchet ring having evenly spaced indentations, the ratchet ring being turnable by a ratchet wrench having a spring-loaded pawl.

Abstract: An improved apparatus for blow molding and conditioning synthetic resin containers, comprising 2 end walls, to which the permanent molds that jointly constitute one (1) forming mold are locked in a removable fashion, these being movable synchronously between 2 stations, namely an extrusion and a blowing station, powered concurrently in opposite directions by the operating devices with which the apparatus is equipped. Into the forming mold, at the extrusion station, is extruded a tubular element of synthetic resin having notable plastic deformation characteristics which, as a result of compressed air being blown therein, is formed into a corresponding synthetic resin container.

Abstract: In extrusion blowing a hollow member, a preform is extruded and then blown in a mold to produce the final member. The weight of the hollow member is determined after its removal from the mold and compared to a reference value, thereby to adjust the size of the extrusion discharge opening to control the amount of material in the preform. The length of the preform is detected to control the movement of the mold thereby to keep a substantially constant length of extruded preform, while the time required to produce a preform is also maintained at a substantially constant value.

Abstract: A lower mold half is horizontally placed. The top surface of the lower mold half is provided with a first groove of any desired shape, one end of which is closed with the other end having a notch for allowing air to be blown in. An upper mold half has a bottom surface which matches the top surface of the lower mold half and which is provided with a second groove corresponding in shape to said first groove. Thus, when the upper and lower mold halves are brought into contact, there is formed a mold cavity defined by the first and second grooves. A discharging unit including a nozzle for discharging a parison is disposed above the lower mold half and the nozzle is so provided that it can rotate in either direction at a variable speed. At least one of the nozzle and the lower mold half is movably provided to lay a parison in the first groove.

Abstract: A device for improving the control of the shape of a parison of a blow molding machine. The device has an inner nozzle positioned below the lowermost level of the parison and directed upwardly toward the open end of the parison. The device may be adapted to pivot so that a deflector plate is moved below the finished part.

Abstract: An apparatus is disclosed for preparing a tubular parison, which is continuously extruded in an extrusion direction from an extrusion head, and for subsequently transferring the parison to a blow molding machine. The apparatus provides improved control of the wall thickness of the parison and can be used with particular advantage in making articles requiring parisons of large diameter and length. The apparatus includes a parison stretching mechanism that grasps and seals the parison at one location along its length and stretches the parison at a controlled rate while being extruded in the extrusion direction. The apparatus also sequentially severs sections of the parison from the remaining continuously extruded portion and transfers each section to a stationary blow molding machine out of the path of this remaining portion.

Abstract: Blow-moulding apparatus for the manufacture of hollow bodies from a thermoplastic in which a screw extruder extrudes the thermoplastic into an accumulating chamber, and a piston forces the thermoplastic through a gap-like outlet orifice of the accumulator chamber to form a parison. A blow-mould consisting of at least two parts which can be opened is positioned so that the blow-mould encompasses the parison. Control means are provided for adjusting the width of the gap-like outlet orifice of the accummulator chamber as a function of the length of the parison extruded, which length can be detected e.g. by a light beam and a photo-cell.

Abstract: Disclosed are apparatus and a method for forming multi-directionally oriented plastic articles by shearing a thermoplastic material in a non-linear shear pattern while the material is at a temperature conducive to orientation and further processing the material by known plastic forming techniques to form an article in which the material remains oriented. More specifically, thermoplastic material is plasticized and accumulated in an amount at least sufficient to form the article, and the material is expressed under pressure from the accumulated body to and through an orifice. The material is non-linearly sheared prior to its issuance from the orifice to induce orientation stresses into the material, and, during shearing, the material is at a temperature which is conducive to orientation.

Abstract: Apparatus for producing corrugated thermoplastic tubing of the type comprising a pair of complementary upper and lower mold assemblies each having an endless chain of articulately interconnected mold blocks which are driven along a forward run and back along a return run, the mold blocks cooperating in pairs along the forward run to form an axially extending tubular mold tunnel, within which the tubing is expanded by vacuum forming or blow molding. The mold blocks have mold-defining faces of corrugated form with alternating troughs and crests. Each mold block is formed with passages which extend between the bases of the troughs of the corrugations and the exterior of the mold block. These passages communicate with the base of each trough throughout its length, and serve to permit the escape of any atmospheric air which is trapped by the tubing in the troughs during expansion of the tubing.

Abstract: A method for forming multi-directionally oriented plastic articles by shearing a thermoplastic material in a non-linear shear pattern while the material is at a temperature conducive to orientation and further processing the material by known plastic forming techniques to form an article in which the material remains oriented. More specifically, thermoplastic material is plasticized and accumulated in an amount at least sufficient to form the article, and the material is expressed under pressure from the accumulated body to and through an orifice. The material is non-linearly sheared prior to its issuance from the orifice to induce orientation stresses into the material, and, during shearing, the material is at a temperature which is conducive to orientation.

Abstract: A moulding apparatus having a two-part mould movable between a receiving station at which thermoplastics synthetic material is extruded into the mould and a release station at which a moulded hollow body is removed from the mould. This hollow body is then supported by a blowing and calibrating member before being gripped by a two-part gripper which moves the body from the release station to a transfer station in synchronism with the mould movement. The gripper parts are mounted on arms or levers supporting and/or guiding the mould parts.

Abstract: An accumulator head is described as having an annular accumulation chamber, an annular ring-piston movable axially through the chamber, an inlet through which plasticized resinous material is forced into the chamber between opposing ends thereof, and a special feature built into the ring-piston which causes material, flowing into the chamber, to wipe the face or tip of the piston and keep it clean and free of any material. A discharge passageway leads from the accumulation chamber to a discharge orifice adjacent which a parison is formed by resinous material from the chamber. Another inlet is provided in the discharge passageways as a means of providing a final, outer layer or laminate of material to that flowing out the discharge passageway from the chamber.

Abstract: Large blow molded objects are produced by extruding a generally tubular form in a horizontal direction so as to form a large pillow shaped object upon sealing. The sealed pillow shaped article is severed and conveyed to a mold having a predetermined configuration and blow molded into a desired shape. The horizontal production of the parison used for blow molding permits the production of large parisons without the sag associated with a vertical process and also permits continuous coextrusion of large parisons without the need for complex accumulating equipment.

Abstract: An accumulator head is described as having an annular accumulation chamber, an annular ring-piston movable axially in the chamber for forcing resinous material from the chamber through an annular discharge passageway leading from the chamber to an annular discharge orifice which, for example, is in communication with a blow mold. An annular inlet is provided in the discharge passageway between the chamber and orifice as a means whereby resinous material is moved into the discharge passageway to add an outer laminate to material flowing through the discharge passageway, or as a means of filling the accumulation chamber with a slug of material.

Abstract: A blow molding machine for the manufacture of products such as bottles from a continuously extruded parison of plastic material. Two pairs of horizontally reciprocable mold sections alternately take a parison from a central station and transport it to either of two blow molding stations having vertically movable blow pins. The mold section platens carry laterally extending trimming elements and, when each pair of mold sections returns to retrieve another parison, the trimming elements trim flash from the molded product which hangs from the blow pin. The product is then transported to a delivery station by the trimming elements as the mold sections return to the blow molding station. The platens and blow pin stations are all supported by the vertically reciprocable table. As a knife severs the parison held by a pair of mold sections from the extruder and the mold sections start moving toward the mold station, the table lowers to prevent resticking of the material being continuously extruded.

Abstract: An apparatus for instruction in the techniques of blow molding includes an air cylinder actuated ram parison extruder secured atop a frame carrying a low mass mold set. The mold set includes two thin wall mold segments mounted for reciprocal travel toward a closed position at a molding station. Each mold segment is adjustably secured to one of a pair of webbed, heat dissipating jaws with each jaw being adjustably mounted to a worm-driven carriage. Mold segment set up is accomplished by loosely mounting the jaws to their respective carriages and the mold segments to their jaws; the jaws are brought toward one another to close and align the mold segments. With the segments closed and registered, they are then tightened to the jaws and the jaws to the carriages thereby assuring repeated registration of the mold segments during molding cycles.

Abstract: A molding device for the manufacture of hollow plastic articles comprising of a two part separable mold, a pre-cast station, a blow station, means for moving the mold halves between the closed and open positions, and means for moving the mold between the preform station and blow station. The mold is supported for movement between the open and closed position by a single supporting spar and locking means are employed for locking the mold parts in the closed position.

Abstract: A blow molding machine for the manufacture of products such as bottles from a continuously extruded parison of plastic material. Two pairs of horizontally reciprocable mold sections are shown which alternately take a parison from a central station and transport it to either of two blow molding stations having vertically movable blow pins. The mold section platens carry laterally extending trimming elements and, when each pair of mold sections returns to retrieve another parison, the trimming elements trim flash from the molded product which hangs from the blow pin. The product is then transported to a delivery station by the trimming elements as the mold sections return to the blow molding station. The platens and blow pin stations are all supported by a vertically reciprocable table. As a knife severs the parison held by a pair or mold sections from the extruder and the mold sections start moving toward the mold station, the table lowers to prevent resticking of the material being continuously extruded.

Abstract: A lower mold half is horizontally placed. The top surface of the lower mold half is provided with a first groove of any desired shape, one end of which is closed with the other end having a notch for allowing air to be blown in. An upper mold half has a bottom surface which matches with the top surface of the lower mold half and which is provided with a second groove corresponding to said first groove. Thus, when the upper and lower mold halves are in contact, there is formed a mold cavity defined by the first and second grooves. A nozzle for discharging a parison is disposed above the lower mold half. The relative positional relation between the nozzle and the lower mold half is changed in such a manner that the nozzle follows the first groove without changing the distance therefrom so that a parison can be properly placed in the first groove. If at least two lower mold halves are provided, it is possible to carry out molding operation continuously.

Abstract: The method and apparatus are useful in forming a parison which has a varying wall thickness and an outer diameter larger than the outer diameter of the annular outlet orifice from which the parison is extruded. Such a parison is obtained by adding additional molten thermoplastic material to the parison while extruding the same to vary the thickness of portions of the parison. The additional molten material is directed radially outwardly from the axis of the parison to increase the wall thickness and to increase the swell of the parison which is defined as the ratio of the inner diameter of the parison to the outer diameter of the outlet orifice. Also the ratio of the outer diameter of the parison to the inner diameter of a mold in which the parison is blowmolded into a container is reduced permitting a larger container to be formed from the thicker portion of the parison while having a small entrance opening formed from a thin wall portion of the parison.

Abstract: A tire shaped article is blow molded by extruding a tubular parison between movable mold sections, sealing the open end of the parison, injecting air into the parison, moving a lower mold section and the bottom portion of the parison upwardly and expanding an intermediate portion of the parison radially outwardly into a mold cavity.

Abstract: A rotary blow molding machine includes a rotor mounted on a horizontal driving shaft, a recovery hopper, an ejector mechanism, and mold stations mounted on the outer periphery of the rotor, which mold stations are radially disposed and circumferentially equally spaced, the mold stations each carrying thereon a split mold unit capable of opening and closing in the direction of the width of the outer peripheral surface of the rotor by a mold opening/closing mechanism, a mold clamping mechanism and a flash blow-pipe, the said split mold unit having a mold-release mechanism. It is so constructed as to produce blow moldings successively continuously at high speed and completely automatically during a single rotation of the mold stations on and along the same circular rotation track.

Abstract: Apparatus for blow molding consisting of a preform station where a blank is shaped around a mandrel and a blow station where the blank is formed in a mold, the mandrel being removed from the blank and a compressed air member being applied to the orifice of the blank.

Abstract: In apparatus for producing corrugated thermoplastic tubing and which comprises a pair of complementary upper and lower mold assemblies each having an endless array of articulately interconnected mold blocks which are driven along a forward run and back along a return run, the mold blocks co-operatively interengaging in pairs along said forward run to form an axially extending tubular mold tunnel, there is disposed at the entrance to the tunnel an extrusion head having an inner core member and an outer member which surrounds the core member and is spaced therefrom to define therebetween an annular passage terminating in an annular orifice and through which the tubing of thermoplastic material is extruded for expansion by blow molding within the tubular mold tunnel, the annular orifice having portions of increased width in axial alignment with the locations of interengagement between the mold blocks of the mold assemblies in the forward runs thereof, thereby to provide the tubing with thickened portions at thes

Abstract: As described herein, there is provided safety apparatus for continuous rotary blow molding machines of the type wherein the extruder operates independently of the machine to continuously extrude plastic tube through its die head during the interruption of operation by the blow molding machine. The safety apparatus includes a blow tube mounted on the extruder for directing air under pressure against the plastic tube to deflect the tube away from the molds of the molding machine upon interruption of the operation of the blow molding machine. A conveyor, operative at the same time as the blow tube and extending in a direction coincident with the direction of pressurized air, receives the diverted plastic tube and carries the plastic tube to a receptacle. The blow tube and conveyor remain operative at least until the machine is restarted.

Abstract: A method and apparatus are disclosed for blow molding a container with an angular neck from a parison of thermoplastic material at a single station at which extrusion of the parison, compression molding of the neck of the container and blowing of the parison occurs. In the method, the mold sections, which have a cavity that defines the container with the angular neck, are pivotally mounted so that the parison can be positioned between the open mold sections in the desired location, and after the mold sections are closed on the parison, the mold sections are pivoted so that the angular neck is aligned to receive a blow pin for performing the compression molding and blowing operations.

Abstract: An apparatus for manufacturing a blown hollow body having a closed bottom portion from a synthetic material comprising a ring nozzle extruder, a head portion forming section, and a multisectional blow-mold wherein extension pieces of each mold section from a cutting edge that cuts the extrusion and closes the bottom of the hollow body as the mold sections are brought together just prior to blowing.

Abstract: Means for controlling the action of a blow molding machine of the type having a continuously extruding parison. The control means includes a photocell signal circuit responsive to extrusion of each parison at normal speed to initiate the decompression of a product at the blow molding station and opening and transfer of the mold halves back to the parison station. Should material in the extruder become depleted, the slower parison extrusion time will be detected and initiate signals for an alarm and deactivation of the blow molding machine. Means are also provided for disenabling this alarm and deactivation system if it is desired to "dry cycle" the machine for test purposes without running the extruder.

Abstract: Multiple extrusion head extrusion-blow moulding apparatus, preferably using a common continuously operating extrusion conveyor, in which apparatus the various extrusion heads have their accumulator pistons driven for identical and simultaneous movement during the extrusion strokes either by means of a common drive means or by separate drive means each controlled from a common control means. Common control may also be exercised over the charging stroke of the accumulator piston.Closed loop control over the wall thickness in dependence upon the final length of the parison, as well as open loop control over the wall thickness in response to a desired program may be imposed simultaneously on the extrusion orifice gap width.

Abstract: A tray of thermoplastic material having means releasably latching a power tool in storage position thereon with the tool handle oriented to serve as the carry handle for the tool and attached tray, the tray providing storage for the power cord and accessories. An opening through a wall of the tray is defined by shearing the material during the blow mold cycle.

Abstract: In order, in the molding of corrugated thermoplastic tubing, to overcome the disadvantage that pressurized air which is supplied to a zone within the tube of thermoplastic material as it is extruded from an extrusion head into the entrance of a tubular mold tunnel may tend to cause rupturing of the tube at the area immediately adjacent to the extrusion head where the tube is unsupported by the wall of the tubular mold tunnel the pressurized gas is supplied at a low pressure to a first zone within the tube of thermoplastic material to support the tube against the wall of the tunnel, and pressurized gas at different, successively higher pressures is supplied to second and third zones within the tube to urge the tube outwardly into the corrugations of the tubular mold tunnel. A gas leakage path between the second and third zones permits leakage from the third to the second zone, the pressure in the second zone being controlled by venting gas therefrom at a controlled rate.

Abstract: Apparatus for extruding a plurality of tubes of plastics material simultaneously for blow molding purposes comprising a plurality of extrusion heads, each having an accumulator chamber from which plastics material can be discharged intermittently to form the tubes, and a mechanism operatively connected to discharge means associated with each accumulator chamber for synchronizing the filling and discharging of the accumulator chambers so that a single source of plastics material can be used to fill the accumulator chambers at a substantially uniform rate and the mold halves of a single blow mold can be opened and closed on the extruded tubes which are discharge simultaneously and will be of uniform length.

Abstract: A parison length controller for molding parisons having a predetermined length and a uniform wall thickness distribution over the whole length. A parison lower edge detector is provided for generating the parison lower edge signal when a parison is extruded to a predetermined length, and a parison controller generates the extrusion end signal every time when an extrusion plunger reaches the end of the extrusion stroke. Depending upon whether the parison lower edge signal or the extrusion end signal occurs first, a positive or negative voltage signal of a predetermined magnitude is generated, and the positive and negative voltage signals are accumulated and stored and used as a wall thickness correction signal for forming a parison having a predetermined length.

Abstract: To produce hollow articles of a thermoplastic by extrusion blowing a parison is transferred from the extruder die into the blow mold by means of a gripper device comprising two gripper arms which work hand-over-hand, alternatively grip the parison as it issues from the die and draw it at an adjustable take-off speed, which is greater than the speed of extrusion, into a blow mold waiting under the die, and the blow mold, after the gripper arm has passed the lower edge of the mold, closes about the parison still hanging from the die, the second gripper arm grips the parison just above the blow mold before the parison is severed between the upper edge of the mold and the gripper arm, the filled blow mold makes room for the next blow mold, the parison inserted in the mold is inflated in a manner which is in itself known to form the hollow body, the latter is released from the mold, and the entire sequence is repeated as a continuous set of cycles.

Abstract: A blow molding method and machine and more particularly a method and machine for extruding a multi-layer parison for blow molding, wherein at least two layers of molding plastics, each plastic compensating the poor or undesirable physical and chemical properties of the other plastic and/or each having a different color are forced to flow through different passages having an annular cross sectional configuration, and are joined at the junction of a short passage to be extruded into a multi-layer parison.

Abstract: In order, in the molding of corrugated thermoplastic tubing, to overcome the disadvantage that pressurized air which is supplied to a zone within the tube of thermoplastic material as it is extruded from an extrusion head into the entrance of a tubular mold tunnel may tend to cause rupturing of the tube at the area immediately adjacent to the extrusion head where the tube is unsupported by the wall of the tubular mold tunnel the pressurized gas is supplied at a low pressure to a first zone within the tube of thermoplastic material to support the tube against the wall of the tunnel, and pressurized gas at a higher pressure is supplied to a second zone within the tube to urge the tube outwardly into the corrugations of the tubular mold tunnel. A first sealing arrangement separates the first zone from the second zone which is disposed downstream of the first zone, and a second sealing arrangement defines the downstream end of the second zone.

Abstract: This relates to a lined container, preferably of the fibre drum type, wherein the lining is extruded as an open ended tube and is initially adhered to the bottom or end wall of the container to seal the tube after which the tube is first inflated and blown across the end wall and is then blown within the container so as to conform to the interior configuration of the container body. The tube is formed by an extruder, and/or accumulator capable of intermittent extrusion with there being relative movement between a die associated with the extruder and the container during the extrusion of the tube, and after the entire interior of the container has been lined, there is associated with the die and the container a mold which upon further extrusion of the tube and the blowing of air within the tube the tube either may be caused to fold around the exterior free end portion of the container so as to form therearound or may be shaped to define a flange which is later draped around the container free end portion.

Abstract: An improved method of blow molding bottles of thermoplastic material wherein intermittent extrusion apparatus is employed to produce bottles with finished necks free of external blemishes, the method including the steps of intermittently extruding tubular parisons from an annular orifice, enclosing the first tubular parison in a mold that has an interior cavity that defines the bottle and also defines a dome radiating outward from the upper end of the bottle neck, immediately blowing the parison essentially to the shape of the cavity, but as an incident to the blowing of the parison and to the interruption of the extrusion, causing the thermoplastic material to be severed at the extrusion orifice, and immediately shifting the mold enclosed article to a shaping station while the article is still at a temperature sufficient for subsequent shaping operations, and at the shaping station finish blowing the article while trimming and at least partially compression-molding the neck.

Abstract: A parison of thermoplastic material is extruded through a nozzle, preliminary to blowing, the parison being receivable in a closable blowmold. The portions of the parison which are clamped in the blowmold should have a uniform thickness and, to compensate for different degrees of stretch at various locations, the parison-producing nozzle head is formed with a plurality of flaps or rollers selectively displaceable into the thermoplastic stream to reduce the wall thickness of the emerging parison. According to the invention, the wall thickness of the parison is only partially reduced at predetermined locations about the periphery, during predetermined time intervals in the course of the parison-extrusion process.

Abstract: The invention concerns an apparatus for the continuous production of oriented hollow bodies from a thermoplastic by blow extrusion which comprises a device for the extrusion of at least one continuous tubular parison from the thermoplastic and also comprises (1) at least one station for blow-molding preforms which is capable of receiving at least one preform mold which can seize a length of extruded parison while leaving open one end of this length which protrudes beyond the mold, and which is equipped with at least one blow nozzle which can be introduced into the open and protruding end of the length of parison so as to permit the production of preforms provided with a definitive molded neck (2) at least one fixed station for the heat-conditioning of the preforms to their orientation temperature and (3) at least one fixed station for the final blow-molding of the conditioned preforms equipped with at least one blow nozzle and at least one final blow-mold of which the cavity reproduces the shape of the desire

Abstract: This is an extrusion head for extruding a parison to be blow molded. A shooting mandrel is longitudinally movable within a plastic melt accumulator chamber. After a "shot", the shooting mandrel is in the up position. The plastic melt fed to the plastic accumulating chamber forces the shooting mandrel to the down position as the plastic accumulating chamber is filled. The parison is formed by moving the shooting mandrel upwardly to the up position. The plastic flows around the shooting mandrel as it flows from the accumulating chamber and out of the extrusion head.

Abstract: An extruder head wherein the housing for a mandrel has a lateral inlet for admission of plasticized material into an arcuate bore of the mandrel and the mandrel has two divergent connecting passages which cause the plasticized material to form a first tubular stream with two radial seams at the inner end of an elongated annular chamber which is defined by the housing and mandrel and wherein the material flows toward an extrusion orifice. The inner end of the chamber contains a ring which divides the first stream into two discrete streams one of which flows along a neck portion of the mandrel and the other of which flows around the ring. The two discrete streams merge into a fourth tubular stream downstream of the ring. The periphery of the ring and/or the neck portion of the mandrel has inclined baffles which subdivide the respective discrete stream into several fields whose boundaries at the downstream end of the ring are out of alinement with the seams of the other discrete stream.

Abstract: Internal mandrel process and apparatus for the production of oriented tubular film in which rupture of the extruded tube by the pressure of inflating gas is prevented by means of a cup seal located between the mandrel and inflating zone, the cup seal being in peripheral engagement with the internal surface of the tube and presenting a substantially concave surface to the mandrel.

Abstract: A multilayer parison extrusion molding machine for blow molding which is characterized in that a main extruder and one or more sub-extruders are radially attached to special diehead and said die head comprises a core holder having a core pin at the lower end; a cylindrical mandrel enclosing said core holder; a plurality of sleeves surrounding said mandrel; housings surrounding said sleeves respectively; one or more pressure rings controlling the space in molten resin passages; pressure ring adjusting screws; an extrusion die; and a die adjusting screw.

Abstract: A method and apparatus for blow molding plastic articles, particularly containers. The method involves shuttling a pre-form blow mold between a parison forming location and a pre-form blowing location, and the transfer of a blown pre-form to a fixed final blow mold. The movement of the pre-form blow mold, both in its shuttling movement and in its open and closing movement, is utilized to transfer the blown pre-form. A clamp arm is secured to each pre-form mold section for engaging the pre-form at the pre-form blowing location and for transferring the pre-form to the final blow mold as the pre-form blow mold moves.In the use of the method and apparatus for the forming of containers, the clamp arms form the finish-defining portions of the final blow mold. When the pre-form blow mold is at its blowing location, the clamp arms register with the mold cavity of the fixed final blow mold to define the complete final article mold.

Abstract: In a blow molding machine a tubular parison is extruded around a blow pin, a two-part mold is closed and the parison is expanded by air pressure against the internal wall of the mold. Each mold half at its top neck carries a sealing member comprising a first insert, which is a shear insert, in the form of an approximately flat one-half ring to sever the parison against the blow pin; a second insert, which is a seal insert, in the form of a flat approximately one-half ring, to seal the parison against the blow pin; and a base member, in the form of an approximately one-half ring, having an inverted shelf to locate and support the shear and seal inserts.

Abstract: In a blow molding machine a tubular parison is extruded around a blow pin, a two-part mold is closed and the parison is expanded by air pressure against the internal wall of the mold. Each mold half at its top neck carries a sealing member comprising a first insert, which is a shear insert, in the form of an approximately flat one-half ring to sever the parison against the blow pin; a second insert, which is a seal insert, in the form of a flat approximately one-half ring, to seal the parison against the blow pin; and a base member, in the form of an approximately one-half ring, having an inverted shelf to locate and support the shear and seal inserts.

Abstract: .Iadd.An improved extrusion method is provided to produce plastic tubes having at least one end thereof an increased wall thickness. The method includes the steps of continuously advancing plastic material through an extruder to form a cylinder, cooling the extruded cylinder as it passes from the extruder, periodically increasing the speed at which the plastic material is fed to the extruder relative to the speed at which the cylinder is drawn from the extruder to produce a section having an increased wall thickness and dividing the cylinder thus formed. .Iaddend.