Patents by Inventor Henrikus J. H. Pragt

Henrikus J. H. Pragt 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: 5729078
    Abstract: The electric discharge lamp has a discharge vessel (2), which is mounted in an outer bulb (1). A glass sleeve (10) is surrounding the discharge vessel. A coiled wire (11) is used as an envelope (11) to a glass sleeve. The wire is in an electrically floating manner fixed around the sleeve (10), e.g. by clamping fit. The construction of the lamp is simple an effective to protect the outer bulb (1) from being damaged by an explosion of the lamp vessel (2) and to prevent sodium, if present, to disappear from the discharge vessel as a result of photoemission.
    Type: Grant
    Filed: March 14, 1996
    Date of Patent: March 17, 1998
    Assignee: U.S. Philips Corporation
    Inventor: Henrikus J. H. Pragt
  • Patent number: 5532543
    Abstract: An electric discharge lamp has a discharge vessel including pair of opposing planar seals each having a pair of major faces and a pair of minor, side faces. A containment shield surrounds the discharge vessel and includes a glass sleeve and a helically coiled wire secured on the glass sleeve. The glass sleeve is pinched to bevelled ends of the minor, side faces of the seals only and substantially does not engage the major faces of the seal. The wire is fixed around the sleeve in an electrically floating manner, e.g. by clamping fit. With the sleeve secured to the discharge vessel, MH quality photometrics are obtained with a tubular body arc tube without an end coat. The construction of the lamp is simple and effective to protect the outer bulb from being damaged by an explosion of the discharge vessel, and to prevent sodium from disappearing from the discharge vessel as a result of photoemission.
    Type: Grant
    Filed: September 24, 1993
    Date of Patent: July 2, 1996
    Assignee: Philips Electronics North America Corporation
    Inventors: Bart Van Der Leeuw, Albert E. Kowal, Henrikus J. H. Pragt, Joseph E. Canale
  • Patent number: 5471110
    Abstract: A high pressure discharge lamp having a discharge vessel with opposing end chambers includes discharge electrodes each consisting of an open elongate filament of refractory metal wire having a plurality of succesive coil turns extending transverse to the longitudinal axis of the discharge vessel. The filament electrodes are dimensioned so that the discharge arc which terminates thereon is sufficiently retracted into the end chamber of the discharge vessel so that the fill constituents condense on a region of the discharge vessel which is primarily axially between the filament electrodes. In a favorable embodiment, the lamp is a metal halide lamp in which the electrode and the discharge sustaining fill is free of thoria and its compounds.
    Type: Grant
    Filed: September 24, 1993
    Date of Patent: November 28, 1995
    Assignee: Philips Electronics North America Corporation
    Inventors: Bart van der Leeuw, Joseph E. Canale, Albert E. Kowal, Henrikus J. H. Pragt, Thomas W. Morris
  • Patent number: 5406165
    Abstract: An electric lamp has a lamp vessel (2) mounted in an outer bulb (1). A glass containment sleeve (10) surrounds the lamp vessel and is fused to a tipped off exhaust tube (5). A coiled wire (11) surrounds the sleeve 10 and provides further containment. The wire may be fixed to the sleeve (10) by clamping fit. The construction of the lamp is simple and effective to protect the outer bulb (1) from being damaged by an explosion of the lamp vessel (2).
    Type: Grant
    Filed: December 22, 1992
    Date of Patent: April 11, 1995
    Assignee: U.S. Philips Corporation
    Inventor: Henrikus J. H. Pragt
  • Patent number: 5402033
    Abstract: The electric discharge lamp has a discharge vessel, which is mounted in an outer bulb. A containment shield surrounds the discharge vessel and includes a glass sleeve and a helically coiled wire about the sleeve. Electrically isolated clamping leads extending from the seals axially secure the glass sleeve about the discharge vessel so that it is electrically isolated. The wire is fixed around the sleeve in an electrically floating manner, e.g. by clamping fit and/or by bent end portions secured over the ends of the glass sleeve. The construction of the lamp is simple and effective to protect the outer bulb from being damaged by an explosion of the lamp vessel and to prevent accelerated sodium depletion from the discharge vessel.
    Type: Grant
    Filed: September 24, 1993
    Date of Patent: March 28, 1995
    Assignee: Philips Electronics North America Corporation
    Inventors: Bart van der Leeuw, Thomas W. Morris, Joseph E. Canale, Henrikus J. H. Pragt
  • Patent number: 5008592
    Abstract: The halogen incandescent lamp has a tipless lamp vessel (1) having a first seal (3), in which a current supply conductor (7) with a foil-shaped part (9) of small width (w.sub.1) is accommodated, and a second seal (4), in which a current supply conductor (8) with a foil-shaped part (10) of larger width (w.sub.2) is accommodated. This construction permits a simple method of manufacturing the lamp, in which the tube from which the lamp vessel (1) is formed has a constriction which allows the first current supply conductor (7) and the filament (5) to pass, but stops the foil-shaped part (10) of the second current supply conductor (8) and holds the filament positioned in axial direction in the tube.
    Type: Grant
    Filed: October 23, 1989
    Date of Patent: April 16, 1991
    Assignee: U.S. Philips Corporation
    Inventor: Henrikus J. H. Pragt