Patents by Inventor Ulf Melhus

Ulf Melhus 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: 5069135
    Abstract: The present invention relates to a method and an apparatus for producing rapid cross-ignition of preferably elongate powder or pyrotechnic charges, such as the propellant charges in impulse motors for correcting the trajectory of shells, rockets and missiles. The cross-ignition is produced by initiation of an elongate, extremely fast-burning or detonating primer charge with an extremely low explosive force which has been arranged in contact with at least part of the periphery of the propellant charge. The primer charge forms a tube whose cross-ignition effect is advantageously complemented by an inner, slower burning powder core which is combusted with deflagration.
    Type: Grant
    Filed: December 7, 1989
    Date of Patent: December 3, 1991
    Assignee: Aktiebolaget Bofors
    Inventors: Sven-Eric Johansson, Ulf Melhus, Lennart Selin
  • Patent number: 4756252
    Abstract: The invention deals with a method of eliminating the base resistance of a flying object. Included in the invention is a device specially adapted to the method. According to the invention base resistance is eliminated by means of the combustion gases from a combustion chamber (2) built into the object being released from the said chamber and led towards the base surface of the object via devices (9-16, 20, 24 and 30) which eliminate the greater part of the gases' motive energy before or simultaneously with their reaching an outlet located on the base surface of the object through which they are allowed to flow out under such conditions that the base resistance of the object (1, 26) is at least partly eliminated.
    Type: Grant
    Filed: October 22, 1981
    Date of Patent: July 12, 1988
    Assignee: Aktiebolaget Bofors
    Inventors: Ulf Melhus, Lennart Johansson, Arne Franzen, Boo Bolinder
  • Patent number: 4688465
    Abstract: The present invention relates to a method and an apparatus for production of cartridged propellant charges for barrel weapons with charge weights up to 1.4 kg/liter.According to the invention, more granular or particle-shaped propellant powder is driven down or compacted than can be housed in free-running condition within the same volume by means of a piston or plunger (6) in a single stage down into a case (4) the inside of which is coated with a friction-reducing coating. The piston or plunger (6) can then be provided with an elastically deformable leading part (7) of e.g. rubber and/or with a conically tipped leading end (7a). According to one variant of the invention the powder is pressed down into a bag (12, 13) of combustible fibre material which has been inserted in advance down into the case (4) coated internally with a friction-reducing coating or which has itself been impregnated with a friction-reducing coating.
    Type: Grant
    Filed: February 20, 1985
    Date of Patent: August 25, 1987
    Assignee: Aktiebolaget Bofors
    Inventors: Ulf Melhus, Mats Olsson, Nils-Gunnar Bjorkqvist, Lars-Erik Bjorn, Dennis Taylor