Patents by Inventor Leonard van der Meulen

Leonard van der Meulen 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: 4437373
    Abstract: An arrangement for perforating foils, particularly of synthetic plastic material, has an elongated cutter and a counterelement movable relative to one another in a direction of elongation of the cutter and also toward one another, wherein the cutter is provided over its entire length with an uninterrupted cutting edge, and the counterelement is composed of a plurality of rollers movable about their axes and located adjacent to one another, so as to provide for selective perforating or cutting.
    Type: Grant
    Filed: July 23, 1982
    Date of Patent: March 20, 1984
    Inventor: Leonard Van Der Meulen
  • Patent number: 4332578
    Abstract: An apparatus for making thermoplastic carrier bags (so-called T-shirt bags) comprises means for feeding a continuous tubular strip of thermoplastic film, either side of which comprises a gusset fold, said strip being advanced with a constant velocity to a cylindrical drum the housing of which comprises embedded heatsealing means, said apparatus further comprising a cutting member and a transverse cutting knife co-operating with the strip said member sequentially providing the tubular strip with a U-shape cut upstream of the drum and said cutting knife operating synchronously with the cutting member in co-operation with the drum for transversely cutting through the strip somewhat beyond the legs of said U-shape cut so as to produce strip portions, said drum further comprising folding means for said strip portions.
    Type: Grant
    Filed: August 18, 1980
    Date of Patent: June 1, 1982
    Inventor: Leonard van der Meulen
  • Patent number: 4295644
    Abstract: In a machine for stacking bags manufactured from thin thermoplastic foil material, the combination of a rotatable supporting drum with radially projecting collecting pins and clenching means for the bags, said means comprising a radially and tangentially displaceable and blade-shaped retaining member(s) mounted on the drum and further comprising transverse beams circulating in closed circuit a portion of which mainly coincides with a sector of the periphery of the drum, the actuation of the retaining members taking place through a system of levers cooperating with cams.
    Type: Grant
    Filed: July 5, 1979
    Date of Patent: October 20, 1981
    Inventor: Leonard van der Meulen
  • Patent number: 4214509
    Abstract: A method and apparatus for making bags from a thin thermoplastic material supplied as either a flat tube or a double-folded web to an advancing supporting path such as the common opposite flights of two sets of endless conveyors, thereby applying the loop-system principle, the supporting conveyors clamping the material at spaced intervals with two sets of clamping beams, lying close to each other, a separate set of cooperating sealing beams cooperating with the thermoplastic material for making the seals within the space between both sets of clamping beams.
    Type: Grant
    Filed: May 25, 1978
    Date of Patent: July 29, 1980
    Inventor: Leonard Van der Meulen
  • Patent number: 4198259
    Abstract: Apparatus for the manufacture of bags from a web of plastic material while applying the principle of loop formation, comprising a plurality of supports, traveling in a first endless path said supports carrying and holding the web by means of suction, further comprising heatsealing members moving in a second endless path, a part of which coincides with a portion of said first endless path for severing and heatsealing the web at spaced intervals so as to form bags, said supports with the bags passing through a cooling zone downstream of said common portion of both paths, said apparatus comprising means for taking the bags off from the supports.
    Type: Grant
    Filed: May 30, 1978
    Date of Patent: April 15, 1980
    Inventor: Leonard van der Meulen
  • Patent number: 4170927
    Abstract: An apparatus for depositing and batching lengths or sheets of foil material at a collecting station, said material being delivered by a production machine in an uninterrupted flow, the apparatus comprising a rotatably mounted supporting structure provided with pivotally arranged support members which together constitute a cylindrical mantle face, said support members being able to unfold themselves for cooperation with stationary collecting pins along the periphery of said supporting structure, after which said support members collapse again.
    Type: Grant
    Filed: February 22, 1978
    Date of Patent: October 16, 1979
    Inventor: Leonard van der Meulen
  • Patent number: 4023470
    Abstract: A method for continuous fabrication of bags from a longitudinally advanced two-layer thermoplastic film web fed tangentially onto a rotating drum for carrying out transverse web seam welding and severing, with high speed operations facilitated by tensioning the web as it is being fed onto the drum, and with web tension release just before or as the seam welding is effected to ensure good quality seaming.
    Type: Grant
    Filed: January 10, 1975
    Date of Patent: May 17, 1977
    Inventor: Leonard van der Meulen