Patents by Inventor Derk VAN DER Scheer

Derk VAN DER Scheer 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: 5006681
    Abstract: A leaf spring system, in particular for influencing a least one body operating or comprising one or more contacts of an electric switch, with a frame aperature and at least one leaf spring which can act on the at least one body. The leaf spring system comprises a supporting frame for receiving the leaf spring in the frame aperture thereof. The spring is supported at one end and has another projecting free end whereby the one body to be influenced by the spring action is accommodated between this other end and the supporting frame. The dimension of the body in the frame aperture is greater than the distance between the edge of the supporting frame and the free end of the at least one leaf spring when the latter is situated essentially in the plane of the supporting frame. The supporting frame is secured against movement relative to the leaf spring and body. The invention further relates to electric switches provided with such a leaf spring system.
    Type: Grant
    Filed: December 28, 1988
    Date of Patent: April 9, 1991
    Assignee: Holec Systemen en Componenten B.V.
    Inventors: Albert J. Postmus, Derk van der Scheer
  • Patent number: 4935711
    Abstract: An electromagnetic switch with a housing provided with at least one magnet system, comprising a stator body of magnetic material having an oblong chamber accomodating a movable armature of magnetic material, with an exciter winding for the excitation of a magnetic field in the at least one magnet system. A swingably supported first arm which can be brought into motion under the influence of the excited magnetic field. To actuate a pair of contacts a swingably supported second arm is provided and on each of the first and second arms one end of at least one leaf spring acts. The first and second arms extend on either side of the chamber at right angles to the lengthwise direction thereof in such a way that each of them can swing about their support point in the direction of the armature which is movable in the chamber between the arms. The free end of the first arm is coupled to the armature, which has an operating element which acts on the second arm.
    Type: Grant
    Filed: December 28, 1988
    Date of Patent: June 19, 1990
    Assignee: Holec Systemen en Componenten B.V.
    Inventors: Derk Van der Scheer, Johannes T. Hopman, Jan W. Hoekstra
  • Patent number: 4562320
    Abstract: Electric current is limited in a current interruption device including two stationary contacts with terminals and a bridging contact movable toward and away from a position bridging the stationary contacts by a conductor connected to each of the stationary contacts and an interconnection of the ends of the conductors remote from the stationary contacts to provide a parallel current path other than the current path for the arc with the current being interrupted when the bridging contact moves away from its bridging position at a value of the current flowing through the conductors such that upon interruption of the current therethrough the voltage across the stationary contacts is sufficient to generate an arc therebetween with the arc travelling along the conductors away from the stationary contacts by the magnetic field generated from the current flowing through the conductors.
    Type: Grant
    Filed: December 15, 1980
    Date of Patent: December 31, 1985
    Assignee: Hazemeijer B.V.
    Inventor: Derk van der Scheer
  • Patent number: 4542364
    Abstract: A tubular shaped high voltage fuse, with a support tube of insulating material, having applied thereon parallel fuse conductors, and an outer tube of insulating material, surrounding the support tube. The end cap consists of a cup-shaped electrically conducting cap to be placed upon the ends of the support tube and the outer tube, a tore-shaped, closed helical contact spring of electrically conducting material to be placed around the support tube end for connecting the fuse conductors with the cap and a spacing piece of insulating material having resilient strips connected therewith for compensating tolerance deviations and for centering, together with the helical spring, the support tube within the outer tube.
    Type: Grant
    Filed: March 16, 1984
    Date of Patent: September 17, 1985
    Assignee: Hazemeijer B.V.
    Inventor: Derk van der Scheer
  • Patent number: 4536735
    Abstract: The invention relates to an assembly for a current limiting high voltage fuse, comprising a preferably tubular support body (1), consisting of quartz glass, and fusible conductors (2) attached over their entire length to the support body, which conductors (2) are of a width of minimum 0.5 mm and maximum 1 mm and of a thickness of maximum 50 .mu.m.These fusible conductors are applied in parallel paths, the distance between the paths being at least twice as large as the width of the fusible conductors. Also the fusible conductors are provided with narrow sections (4) separated in longitudinal direction of the fusible conductor over regular distances, and interconnected at both ends by an electrically conducting sleeve (3) applied to the support body (1).
    Type: Grant
    Filed: February 15, 1984
    Date of Patent: August 20, 1985
    Assignee: Hazemeijer B.V.
    Inventor: Derk van der Scheer
  • Patent number: 4354215
    Abstract: In a selective safety device for the protection of successive power levels in a power distribution system, a current limiting switch is provided in each of the power levels and includes a current-limiting quick-switching contact which is so positioned at the power supply side in each one of the different power levels such that the current limiting switch immediately in front of a fault is switched off upon occurrence of a fault. A resistor is connected across each of the quick-switching contacts and is serially connected in the interrupted circuit upon the opening action of the quick-switching contact. Additionally, a slow-switching contact is serially connected with each of the quick-switching contacts to be opened after opening of the quick-switching contact with a presettable delay time, which is dependent upon the power levels in which the slow-switching contact is connected.
    Type: Grant
    Filed: June 11, 1980
    Date of Patent: October 12, 1982
    Assignee: Hazemeijer B.V.
    Inventor: Derk van der Scheer
  • Patent number: 4319210
    Abstract: Current limiting switch for rapid circuit breaking, including at least one pair of contacts, one contact being mounted stationary and the other being mounted on a movable arm. The contact arm is rotatable about a fixed point upon surpassing a predetermined current threshold value, by means of an electromagnet energized by the current passing through the switch. The electromagnetic means comprise an electromagnet and a first and a second armature cooperating with the electromagnet, in which the first armature drives the movable contact in the direction of disengagement and the second armature releases a locking device, which blocks the movable contact in the direction of movement until the current threshold is reached.
    Type: Grant
    Filed: May 19, 1980
    Date of Patent: March 9, 1982
    Assignee: Hazemeijer B.V.
    Inventors: Derk van der Scheer, Hendrik A. Bosch
  • Patent number: 4172241
    Abstract: An actuation device which includes a holding magnet, an attracting magnet and an armature therebetween, both magnets being excitable by the same electromagnetic source. The armature comprises two half portions interconnected by a non-magnetic plate and operating such that upon saturation of the holding magnet with current, the armature will be disengaged by the holding magnet and drawn towards the attracting magnet.
    Type: Grant
    Filed: August 9, 1977
    Date of Patent: October 23, 1979
    Assignee: Hazemeijer B. V.
    Inventors: Hendrik A. Bosch, Derk VAN DER Scheer