Patents by Inventor Hendrik Roelofs

Hendrik Roelofs 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: 7169828
    Abstract: The invention relates to a method of manufacturing a replica, which method comprises the provision of a polymerizable resin composition between a front mold having a pre-shaped surface and a back mold having a pre-shaped surface, carrying out a curing treatment and removing the replica thus manufactured from the molds. The invention further relates to a replica obtained by carrying out a UV light-initiated cationic polymerization.
    Type: Grant
    Filed: December 16, 2002
    Date of Patent: January 30, 2007
    Assignee: Koninklijke Philips Electronics N.V.
    Inventors: Johan George Kloosterboer, Fredericus Johannes Touwslager, Emile Johannes Karel Verstegen, Hendrik Roelof Stapert
  • Patent number: 6349784
    Abstract: The invention provides a motorcycle with hub steering, the axle of the hub being fixedly connected to first support arms and being disposed in such a manner that it can turn with respect to the hub body. Second support arms are arranged in such a manner that the front pivot points and rear pivot points lie on non-parallel lines. Attaching the front wheel in this way results in an improved suspension and increased stability of a motorcycle with hub steering.
    Type: Grant
    Filed: July 5, 2000
    Date of Patent: February 26, 2002
    Assignee: Chiqane B.V.
    Inventor: Hendrik Roelof van der Heide
  • Patent number: 6172167
    Abstract: The invention provide biodegradable copolymers of the copoly(ester-amide) or copoly(ester-urethane) type, which copolymers consist of building blocks with the general structure (I): [CB-VB] wherein CB and VB of different building blocks may be the same or different, and CB represents a block with a constant length and VB represents a block with a variable length.
    Type: Grant
    Filed: July 21, 1999
    Date of Patent: January 9, 2001
    Assignee: Universiteit Twente
    Inventors: Hendrik Roelof Stapert, Pieter Jan Dijkstra, Jan Feijen
  • Patent number: 4401914
    Abstract: Low-pressure sodium vapor discharge lamp comprising a hollow inner member surrounded by an outer member, the wall of at least one of the members having grooves and the members of that portion, located between the grooves, extending to or to near the wall of the other member and a discharge space being formed wherein a discharge path, folded by means of the grooves, is present, the portions located between the grooves and facing the wall of the other member and extending to or to near the wall of the other member being provided with intervening portions extending in parallel with that wall.
    Type: Grant
    Filed: February 2, 1981
    Date of Patent: August 30, 1983
    Assignee: U.S. Philips Corporation
    Inventors: Gustaaf A. Wesselink, Hendrik Roelofs, Cornelis H. M. Van Bommel
  • Patent number: 4260931
    Abstract: Low-pressure mercury vapor discharge lamps of the fluorescent type are known which comprise two nesting glass members so grooved as to provide between their nesting surfaces a circuitous ("folded") discharge path between two electrodes, the length of the discharge path being considerably greater than the physical distance between the electrodes. The whole surface of each glass member is coated with luminescent material with the result that, when the lamp is in use, the portions of the members not surrounding the discharge appear dark due to their poor light transmissibility. According to the invention, these portions of the two members are not coated with luminescent material and thus act as windows for light generated in the luminescent layers facing the lamp axis. Preferably, a fluted reflector is provided inside the lamp.
    Type: Grant
    Filed: February 12, 1979
    Date of Patent: April 7, 1981
    Assignee: U.S. Philips Corporation
    Inventors: Gustaaf A. Wesselink, Hendrik Roelofs, Cornelis H. M. Van Bommel
  • Patent number: 4237400
    Abstract: Low-pressure discharge lamp having a discharge space, limited by an elongate lamp vessel, electrodes at one end of the vessel in the discharge space between which electrodes a discharge takes place during operation of the lamp. The lamp vessel has partitions to divide the discharge space into each extending substantially in the length of the discharge vessel which chambers communicate with one another via at least one opening. The chambers are sequentially passed through by the discharge, the opening between at least two chambers being at least partly wedge-shaped, the minimum width being located nearest to an electrode whose discharge path extends itself after ignition.
    Type: Grant
    Filed: February 21, 1979
    Date of Patent: December 2, 1980
    Assignee: U.S. Philips Corporation
    Inventors: Gustaaf A. Wesselink, Hendrik Roelofs, Cornelis H. M. Van Bommel
  • Patent number: 4221988
    Abstract: A low pressure gas discharge lamp having a body present in the discharge vessel which consists of a longitudinal support which extends into the longitudinal direction of the vessel, the support being provided with fibers which are distributed over the space within the discharge vessel and extend substantially transversely from the support.
    Type: Grant
    Filed: October 31, 1978
    Date of Patent: September 9, 1980
    Assignee: U.S. Philips Corporation
    Inventors: Jan Hasker, Petrus R. van Ijzendoorn, Hendrik Roelofs
  • Patent number: 4143447
    Abstract: A method for manufacturing a low pressure gas discharge lamp having a body present in the discharge vessel which consists of a longitudinal support which extends into the longitudinal direction of the vessel. The support being provided with fibres which are distributed over the space within the discharge vessel and extend substantially transversely from the support.
    Type: Grant
    Filed: February 13, 1978
    Date of Patent: March 13, 1979
    Assignee: U.S. Philips Corporation
    Inventors: Jan Hasker, Petrus R. VAN Ijzendoorn, Hendrik Roelofs
  • Patent number: 4074172
    Abstract: The invention relates to a device for operating a low-pressure sodium vapor discharge lamp without a stabilizing ballast.The lamp is provided with a discharge tube having first and second main electrodes opposing a third main electrode. An automatically operating change-over switch occasionally switches the lamp current to either the first or second electrodes. A reservoir of liquid sodium near the first electrode affects sodium vapor pressure in the discharge tube by the switching action.
    Type: Grant
    Filed: March 3, 1976
    Date of Patent: February 14, 1978
    Assignee: U.S. Philips Corporation
    Inventors: Gustaaf A. Wesselink, Hendrik Roelofs, Gijsbert J. Ponsen
  • Patent number: 3959682
    Abstract: Electric lamp having a hermetically sealed gas-filled hard-glass or vitreous-silica lamp envelope provided with a current lead-in which is sealed into a portion of the lamp envelope and comprises a foil mainly consisting of molybdenum and a current supply lead mainly consisting of tungsten which is secured to the foil by a welded joint and extends into the lamp envelope. The welded joint contains iron or an alloy of at least 50% by weight of iron and one or more of the elements scandium, titanium, vanadium, chromium, manganese, cobalt, nickel and copper as the welding agent.
    Type: Grant
    Filed: February 27, 1975
    Date of Patent: May 25, 1976
    Assignee: U.S. Philips Corporation
    Inventors: Gustaaf Adolf Wesselink, Arie Koelewijn, Hendrik Roelofs