Patents by Inventor Jobst U. Gellert

Jobst U. Gellert has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5387099
    Abstract: Valve gated injection molding apparatus wherein the reciprocating valve member extends into the melt passage through a sealing bushing. The sealing bushing has a thin steel collar portion which extends forwardly into the melt passage and fits around the valve member to form a seal against leakage of melt rearwardly along the valve member. In the preferred embodiments, the collar portion is thin enough that it is slightly compressed around the valve member by the pressure of the surrounding melt in the melt passage to improve the seal.
    Type: Grant
    Filed: March 7, 1994
    Date of Patent: February 7, 1995
    Inventor: Jobst U. Gellert
  • Patent number: 5366369
    Abstract: Injection molding apparatus with a number of spaced inserts removably seated in a heated melt distribution manifold. Each insert is seated in a transverse opening through the melt distribution manifold in alignment with a heated nozzle. The insert has a melt duct with a smoothly curved bend extending through 90.degree. to an outlet in matching alignment with a melt bore extending centrally through the nozzle. The insert has an alignment pin which extends outwardly through a matching aperture in the melt distribution manifold into an opening in the mold to both align the insert in the manifold and locate the manifold in the mold. The alignment pin bore is positioned opposite from and in alignment with the inlet to the melt duct so alignment of the melt duct inlet in the insert with a respective branch of a melt passage in the manifold is very accurate.
    Type: Grant
    Filed: July 26, 1993
    Date of Patent: November 22, 1994
    Inventor: Jobst U. Gellert
  • Patent number: 5366370
    Abstract: Multi-cavity injection molding apparatus with hot tip gates extending perpendicular to the direction of mold opening to provide very clean shearing action. The heated nozzles extend diagonally outward in two rows from a pair of diagonal surfaces extending along an elongated melt distribution manifold. Each nozzle has a pointed tip extending outwardly at an angle to its longitudinal axis in alignment with one of the gates. The outward angles of the nozzles themselves and their pointed tips enable the gates to be oriented parallel to the parting line and perpendicular to the direction of mold opening.
    Type: Grant
    Filed: December 21, 1993
    Date of Patent: November 22, 1994
    Inventor: Jobst U. Gellert
  • Patent number: 5346388
    Abstract: An injection molding nozzle upon which a thermocouple element can be removably mounted and be self-retained in place. The nozzle has a front portion and a larger diameter rear collar portion with a thermocouple element duct therethrough. A thermocouple element bore extends rearwardly from the front end of the nozzle and a thermocouple element groove extends outwardly across the rear end from the thermocouple element duct. A front portion of a suitably bendable and retentive thermocouple element is inserted into the bore in the front end and bent to extend rearwardly to the duct through the rear collar portion. A rear portion of the thermocouple element is bent into place in the groove in the rear end. The thermocouple element securely retains itself in this position while the nozzle is being installed in the mold.
    Type: Grant
    Filed: August 16, 1993
    Date of Patent: September 13, 1994
    Inventor: Jobst U. Gellert
  • Patent number: 5334008
    Abstract: Injection molding apparatus for valve gating in which the valve member extends through a locating insert mounted at the front end of the nozzle. The locating insert has a pair of spiral blades extending inwardly from an outer collar. The spiral blades have curved inner edges which encircle the valve member sufficiently to maintain the valve member in accurate alignment with the gate as it reciprocates between the open and closed positions.
    Type: Grant
    Filed: April 26, 1993
    Date of Patent: August 2, 1994
    Inventor: Jobst U. Gellert
  • Patent number: 5326251
    Abstract: A heated injection molding nozzle having a melt channel which branches outwardly to several spaced edge gates. The nozzle has alternate thermocouple element receiving bores spaced longitudinally along a temperature gradient extending between the heating element and the front end of the nozzle. The nozzle facilitates the temperature control of materials having different thermal characteristics. When molding an amorphous material, a temperature somewhat lower than the prescribed operating temperature is desirable so the thermocouple element is mounted in the rearward bore closer to the heating element. If it is critical to maintain the temperature of the melt near the prescribed operating temperature for a material such as a crystalline material, the thermocouple element is received in the forward bore further along the temperature gradient from the heating element.
    Type: Grant
    Filed: December 6, 1993
    Date of Patent: July 5, 1994
    Inventor: Jobst U. Gellert
  • Patent number: 5318434
    Abstract: Injection molding apparatus wherein a torpedo is mounted at the front end of a nozzle to provide a fixed ring gate. The torpedo has an elongated central shaft with a nose portion which projects forwardly into a cylindrical opening extending through the mold to the cavity. The outer surface of the nose portion is sufficiently spaced from the inner surface of the opening to form the ring gate through which the melt flows into the cavity. The nose portion of the central shaft enhances heat transfer during the injection cycle and thus reduces cycle time and provides cleaner gates.
    Type: Grant
    Filed: April 19, 1993
    Date of Patent: June 7, 1994
    Inventor: Jobst U. Gellert
  • Patent number: 5312242
    Abstract: A heated injection molding nozzle having a cylindrical locating flange extending forwardly from a rear collar portion to mount the nozzle in a well in a cooled mold. The nozzle has a cylindrical central portion with an insulative air space extending between it and the surrounding cooled mold. A hollow thermocouple tube extends through the rear collar portion and along the inner surface of the locating flange to removably receive a thermocouple element which extends from the rear end of the nozzle and through the insulative air space to monitor the operating temperature near the forward end of the nozzle. In the event of pressurized melt escaping to fill the air space, contact of the thermocouple tube with the locating flange cools the melt which flows into the thermocouple tube sufficiently to freeze it and prevent leakage out amongst the wiring in other parts of the mold.
    Type: Grant
    Filed: March 2, 1993
    Date of Patent: May 17, 1994
    Inventor: Jobst U. Gellert
  • Patent number: 5299928
    Abstract: A two-piece injection molding nozzle seal. The inner piece through which the melt duct extends is formed of a highly thermally conductive material to enhance heat transfer during the thermodynamic cycle. The surrounding outer retaining piece which extends from the heated nozzle into contact with the cooled mold to provide the necessary seal is formed of a substantially less conductive material to avoid undue heat loss.
    Type: Grant
    Filed: July 26, 1993
    Date of Patent: April 5, 1994
    Inventor: Jobst U. Gellert
  • Patent number: 5284436
    Abstract: Injection molding apparatus wherein a torpedo is mounted in the front end of a heated nozzle. The torpedo has spaced blades extending inwardly from an outer collar to an elongated shaft which extends centrally in the melt bore. The torpedo shaft has an elongated central portion which is securely press fitted in a steel outer sleeve from which the blades extend. The elongated central portion of the torpedo shaft extends forwardly into the gate, and is formed of an engineered ceramic such as silicon carbide which is very thermally conductive as well as abrasion and corrosion resistant. In one embodiment, the gate extends through a gate insert which is also formed of a thermally conductive and abrasion and corrosion resistant engineered ceramic material.
    Type: Grant
    Filed: April 29, 1993
    Date of Patent: February 8, 1994
    Inventor: Jobst U. Gellert
  • Patent number: 5282735
    Abstract: An injection molding nozzle and method of making it having an electrical heating element extending in a pair of alternating coils in a spiral channel around a central melt passage. The heating element has a U-shaped bend near the forward end of the nozzle and two ends at an external terminal near the rear end. A central wire in the heating element has a fine coiled heating portion extending between two larger diameter conductive portions which extend to the terminal. One of the conductive portions of the central wire is a predetermined length longer than the other and extends in one of the alternating coils of the heating element along a rear portion of the nozzle adjacent the terminal. The heating portion of the wire extends in both of the alternating coils of the heating element along a forward portion of the nozzle so the heating element provides substantially less heat along the rear portion than along the forward portion of the nozzle.
    Type: Grant
    Filed: December 7, 1992
    Date of Patent: February 1, 1994
    Inventor: Jobst U. Gellert
  • Patent number: 5269676
    Abstract: A seating and sealing insert for mounting a heated injection molding nozzle in a well in a mold. The hollow insert has a cylindrical central portion extending between a rear seating portion and a forward sealing portion. The rear seating portion is outwardly flanged to seat in the well in the mold and forms an inner seat to receive a cylindrical support flange of the nozzle to accurately support the nozzle in the well in the mold. The forward sealing portion has a V - shaped forward face and inner and outer surfaces which are forced outwardly by melt pressure to seal against the nozzle and the mold. Thus, the seating and sealing insert provides an insulative air space between the heated nozzle and the surrounding mold and the forward sealing portion prevents the escape of pressurized melt into the insulative air space.
    Type: Grant
    Filed: August 24, 1992
    Date of Patent: December 14, 1993
    Inventor: Jobst U. Gellert
  • Patent number: 5268184
    Abstract: A heated injection molding nozzle having a rear member and a forward member which is removable. A channel extends through the rear and forward members to convey pressurized melt to one or more gates extending through the mold to a cavity. The rear member has an electrical heating element with a spiral portion which extends around the melt channel. The forward member has a tapered rear portion which extends rearwardly into a matching tapered well in the rear member. The taper is sufficient so the tapered portion is frictionally retained in the well to removably mount the forward member to the rear member. This allows the forward member to be easily turned or driven out of engagement in the well to replace it with a new forward member or a forward member having a different configuration to provide a different type or arrangement of gating.
    Type: Grant
    Filed: August 17, 1992
    Date of Patent: December 7, 1993
    Inventor: Jobst U. Gellert
  • Patent number: 5238378
    Abstract: Valve gated injection molding apparatus for coinjecting and/or sequentially injecting two different fluids through a gate into a cavity. An elongated valve pin member is received in an elongated valve sleeve member in alignment with the gate and both are reciprocated rotatably as well as axially by separate actuating mechanisms to control the flow of the fluids through the gate. Each actuating mechanism has a piston driven rack member to provide rotary motion which is then converted to axial movement of the corresponding valve member between the retracted open and forward closed positions. In one embodiment, helical threads on the valve members engage fixed teeth extending inwardly from the surrounding nozzle to convert the rotary motion of each valve member to corresponding axial movement. Linear position transducers on the rack members provide for accurate control of the valve members.
    Type: Grant
    Filed: May 27, 1992
    Date of Patent: August 24, 1993
    Inventor: Jobst U. Gellert
  • Patent number: 5235737
    Abstract: A method of making an injection molding nozzle having an electrical heating element wound in a channel. The heating element has two terminal wires which extend radially outward parallel to each other from either a common end portion or two separate end portions of the heating element. After the heating element is wound in the spiral channel in the nozzle body, forward and rear collar portions are mounted around the nozzle body to form a radial slot or opening between them through which the end portion or portions of the heating element project. A stud portion is mounted to extend radially outward from the slot with a single bore or two parallel bores through which the end portion or portions extend. These components are then brazed together in a vacuum furnace to form a strong integral structure with the end portion or portions of the heating element secured in place. In one embodiment, a spacer portion having two parallel bores is mounted with ceramic paste to the stud portion.
    Type: Grant
    Filed: December 28, 1992
    Date of Patent: August 17, 1993
    Inventor: Jobst U. Gellert
  • Patent number: 5223275
    Abstract: The present invention refers to a hot runner manifold composed of two parallel hot runner plates disposed in parallel, one behind the other, to feed at least two different plastic materials along horizontal hot runners to injection nozzles bolted to the front hot runner manifolds.
    Type: Grant
    Filed: October 2, 1991
    Date of Patent: June 29, 1993
    Inventor: Jobst U. Gellert
  • Patent number: 5206040
    Abstract: This invention relates to a hot tip gated injection molding apparatus having a heated manifold to distribute melt to a number of spaced gates. An unheated sealing and conductive member is mounted directly between the heated manifold and the cooled cavity plate in alignment with each gate. The sealing and conductive member has an elongated hot tip shaft which is connected to extend centrally through the bore of an outer collar portion by a number of spaced spiral blades. The collar portion bridges an insulative air space between the hot manifold and cooled cavity plate to prevent melt leaking into it. Heat received through the rear end of the collar portion which abuts directly against the heated manifold is transferred through the blades and the hot tip shaft to the gate area which is aligned with the pointed forward end of the hot tip shaft. The rear end of the hot tip shaft extends rearwardly into a branch of the melt passage to pick up heat from the surrounding melt.
    Type: Grant
    Filed: February 14, 1992
    Date of Patent: April 27, 1993
    Inventor: Jobst U. Gellert
  • Patent number: 5148594
    Abstract: A method of manufacturing a metallurgically monolithic integral heated probe for injection molding. An electrical terminal and three portions of the probe body are made and assembled together with an electrical heating element extending in an aligned bore. The forward portion is made of abrasion resistant high speed steel, while the rest of the probe body is made of hot work tool steel. A removable and reusable filler tube is screwed into a threaded seat in the rear cap portion and a quantity of silver is loaded into it. After a nickel alloy brazing material is applied to the joins, the assembly is heated in a reduced oxygen atmosphere in a vacuum furnace according to a predetermined cycle. The nickel alloy seals all the joins and the silver braze fills all the spaces between the components to provide a metallurgically monolithic integral probe.
    Type: Grant
    Filed: February 18, 1992
    Date of Patent: September 22, 1992
    Inventor: Jobst U. Gellert
  • Patent number: 5135377
    Abstract: A heated injection molding nozzle for use in an injection molding system for injection molding of several different plastic melts in one injection molding cycle. The nozzle has an elongated nozzle body with first and second longitudinal melt passages for two different plastic materials. The second melt passage is a melt bore which extends centrally through the nozzle body. The first melt passage has two outer melt bores which extend through the nozzle body on opposite sides of the second melt passage. The rear end face of the nozzle body has an off center melt inlet recess and two melt branch passages extending to the two outer melt bores.
    Type: Grant
    Filed: June 6, 1991
    Date of Patent: August 4, 1992
    Inventor: Jobst U. Gellert
  • Patent number: 5125827
    Abstract: An insulative and resilient spacer member to be mounted between a heated manifold and a cooled clamp plate in an injection molding system. The spacer member has a plurality of V-shaped concentric rings. It has a uniform cross section with a number of web portions extending diagonally between alternate forward and rearward ridge portions. The outer surfaces of the alternate ridge portions are aligned to provide forward and rearward sides of the spacer member which extend parallel a predetermined distance apart. Some of the outer surfaces have an inwardly extending insulative circular groove. The spacer member is formed of steel to have a predetermined combination of strength, resilience and reduced thermal conductivity.
    Type: Grant
    Filed: November 4, 1991
    Date of Patent: June 30, 1992
    Inventor: Jobst U. Gellert