Patents by Inventor Karl-Heinz Dreifert

Karl-Heinz Dreifert 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: 5370428
    Abstract: A door- or window sash which is pivotable relative to a door- or window frame between open and closed positions can be releasably affixed to the frame in the closed position in response to turning of a handle which can shift an elongated carrier relative to the frame between two spaced-apart end positions. The carrier supports a series of longitudinally spaced-apart projections each of which fully engages a complementary retainer on the sash during different stages of movement of the handle from one end position to the other end position. The arrangement may be such that the projection nearest to the handle is first to engage the complementary retainer on the sash, that the projection which is adjacent the nearest projection is next to engage the corresponding retainer, and so on. A safety device can be provided to releasably lock the carrier in the other end position.
    Type: Grant
    Filed: June 4, 1993
    Date of Patent: December 6, 1994
    Assignee: Wilhelm Weidtmann GmbH & Co. KG
    Inventors: Karl-Heinz Dreifert, Erhard Kuhnt
  • Patent number: 5318333
    Abstract: A device which can lock a sash to and unlock a sash from a door or window frame has a composite housing which is partially recessed into the frame and receives a portion of a reciprocable plate member which is coupled to one or more motion receiving elements serving to actually lock or unlock the sash. The housing further carries a handle which is pivotable in the plane of the plate member about an axis extending at right angles to such plane, preferably through an angle of approximately 180.degree.. The plate member has one or more sliders which are reciprocable in one or more elongated grooves provided in one or more internal surfaces of the housing. The motion transmitting connection between the handle and the plate member can include a single part, such as a crank, which is non-rotatably connected to the handle and is pivoted to the plate member.
    Type: Grant
    Filed: April 20, 1993
    Date of Patent: June 7, 1994
    Assignee: Wilhelm Weidtmann GmbH & Co. KG
    Inventor: Karl-Heinz Dreifert
  • Patent number: 5111615
    Abstract: A casement window wherein the sash is pivotable in the frame about a vertical axis has a self-locking crank drive which pivots the sash between open and closed positions by way of a pivotable lever, a link which is coupled to the lever, and an actuator which is movably installed in the sash, which is coupled to the link and which forms part of a locking-unlocking mechanism for the sash. The first stage of rotation of the crank drive in order to pivot the sash from closed position involves a displacement of the actuator which ensures that the sash is unlocked, and further rotation of the crank drive results in pivoting of the sash to the open position. If the direction of rotation of the crank drive is reversed, the sash is moved to the closed position before the actuator is caused to lock the sash to the frame. A blocking device for the actuator is operated by the frame to release the actuator for movement to its operative position shortly before the sash reaches the closed position.
    Type: Grant
    Filed: April 15, 1991
    Date of Patent: May 12, 1992
    Assignee: Wilhelm Weidtmann GmbH & Co. KG
    Inventors: Erhard Kuhnt, Karl-Heinz Dreifert