Patents by Inventor Paulus R. Kamstra

Paulus R. Kamstra 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: 4822340
    Abstract: An automatic injector for injecting one or more different injection liquids, comprising a combination of a substantially cylindrical means containing a discharge mechanism and a plurality of cartridge elements. The cartridge elements comprise a piston in the substantially cylindrical means, a sealing stopper, a number of separating stoppers equal to one less than the number of the liquids, and a needle holder with injection needle. The needle holder comprises a stopper that is movable in the substantially cylindrical means and comprises a longitudinal bore. The injector comprises a by-pass means for injection liquid in front of the sealing stopper.
    Type: Grant
    Filed: October 9, 1986
    Date of Patent: April 18, 1989
    Assignee: Duphar International Research B.V.
    Inventor: Paulus R. Kamstra
  • Patent number: 4573972
    Abstract: An automatic device for injecting two or more different injection liquids which may not be in contact with each other for long periods of time: a combination of a discharge mechanism, a cartridge holder and a cartridge which is slidably accommodated in the holder and which includes an ampoule, a piston which is movable in the ampoule and seals same, and a hypodermic needle connected to the front of the ampoule by means of a needle mount.
    Type: Grant
    Filed: December 13, 1983
    Date of Patent: March 4, 1986
    Assignee: Duphar International Research B.V.
    Inventor: Paulus R. Kamstra
  • Patent number: 4573971
    Abstract: An automatic device for injecting two or more different injection liquids which may not be in contact with each other for long periods of time, and including a combination of a discharge mechanism, a cartridge holder and a cartridge slidably accommodated in the holder and including an ampoule, a piston movable in the ampoule for sealing same, and a hypodermic needle connected to the front of the ampoule by a needle mount.
    Type: Grant
    Filed: December 13, 1983
    Date of Patent: March 4, 1986
    Assignee: Duphar International Research B.V.
    Inventor: Paulus R. Kamstra
  • Patent number: 4529403
    Abstract: The invention relates to an automatic syringe for injecting two or more different injection liquids which may not be in contact with each other for long periods of time. For that purpose, the ampoule between the piston and the needle connection includes one or more stoppers which keep the injection liquids separated from each other, while at a point a short distance before the needle connection a by-pass means is present through which the injection liquid or injection liquids present behind the stopper or stoppers can pass the stopper or stoppers during use of the syringe.
    Type: Grant
    Filed: August 5, 1982
    Date of Patent: July 16, 1985
    Assignee: Duphar International Research B.V.
    Inventor: Paulus R. Kamstra
  • Patent number: 4496344
    Abstract: The invention relates to a syringe for injecting two or more injection liquids which may not be in contact with each other for a longer period of time, comprising a barrel having a piston, a needle on the front side of the barrel, a sealing stopper in the barrel on the front, and one or more separating stoppers which, before use of the syringe, keep the injection liquids separated from each other. The needle is connected to the front of the barrel by means of a needle holder comprising a collar to connect the needle holder to the barrel, an neck to connect the injection needle, and a hollow shaft between collar and neck, in which a passage is formed in the inner wall of the shaft and the rear face of the neck, past which passage the injection liquids can reach the cannula when during use of the syringe the stoppers are moved into the shaft of the needle holder.
    Type: Grant
    Filed: August 5, 1982
    Date of Patent: January 29, 1985
    Assignee: Duphar International Research B.V.
    Inventor: Paulus R. Kamstra
  • Patent number: 4469482
    Abstract: The invention relates to a disposable syringe comprising a barrel in which a piston is provided and to which a needle is or can be connected to the front, a stopper being present in the barrel between piston and needle or needle connection means. The inner wall of the barrel is locally deformed between stopper and needle or needle connection so that at the area of the deformation injection liquid can reach the cannula past the stopper and during nurse-aspiration the stopper is held, in which body fluid can reach the part of the barrel present behind the stopper.
    Type: Grant
    Filed: July 26, 1982
    Date of Patent: September 4, 1984
    Assignee: Duphar International Research B.V.
    Inventors: Rokus C. D. Lissenburg, Paulus R. Kamstra