Patents by Inventor Duane M. Beukema

Duane M. Beukema 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: 4776633
    Abstract: An integrated chair and control arrangement is provided for tilt back chairs, and other similar seating. The chair has a base, as well as a back and a bottom or seat which are interconnected for mutual rotation about a common axis. The common axis is located above the chair bottom, forward of the chair back, and generally adjacent to the hip joints of a seated user. A control supports the chair back and chair bottom on the base in a manner such that rearward tilting of the chair back simultaneously shifts the chair back, the chair bottom, and the location of the common axis in a manner which maintains the adjacent spatial relationship between the common axis and the hip joints of the seated user to provide improved comfort and support.
    Type: Grant
    Filed: April 10, 1986
    Date of Patent: October 11, 1988
    Assignee: Steelcase Inc.
    Inventors: Glenn A. Knoblock, Duane M. Beukema
  • Patent number: 4485996
    Abstract: A height adjustor for funiture, such as chairs, and the like, comprises a pair of telescoping tubular members which interconnect base and seat portions of a chair and form a supportive pedestal therefor. A ram is mounted in the tubular members, such that extension and retraction of the ram respectively raises and lowers the chair seat. The ram and tubular members are sized in a manner to form an annular space therebetween which permits the ram to assume an eccentric position in the tubular members during a loaded chair condition. The ram ends are pivotally connected in the tubular members, such that lateral forces (as distinguished from vertical forces) which are applied to a chair seat are supported primarily by the tubular members, and are not transmitted to the ram.
    Type: Grant
    Filed: January 6, 1982
    Date of Patent: December 4, 1984
    Assignee: Steelcase Inc.
    Inventors: Duane M. Beukema, Jack R. Knoblauch
  • Patent number: 4438898
    Abstract: The specification discloses a chair control in which the tiltable member can be locked against movement with respect to the stationary member by means of a rigid locking plate pivotally mounted on the tilting member and rotatable by an actuator rod, having a bell crank type lever formed therein, into close proximity with the stationary member to thereby physically block relative movement between the tiltable and stationary members.
    Type: Grant
    Filed: May 1, 1980
    Date of Patent: March 27, 1984
    Assignee: Steelcase Inc.
    Inventors: Jack R. Knoblauch, Duane M. Beukema, Kenneth W. Hozeski
  • Patent number: 4390206
    Abstract: The specification discloses a synchrotilt chair control in which a slide is provided between the front of the seat support and stationary control housing, which slide serves not only to make possible synchrotilt action between the back support and seat support, but also makes possible the incorporation of a seat adjustment assembly. The latter comprises a pivot bracket pivotally mounted on the slide and on the seat support, and an actuator for pivoting the pivot bracket. The pivotal mounting between the seat support and back support is also dual functional in that it supports a pivotally mounted lock plate for locking the control. A height adjustment actuator and hidden handle pretension adjustment bolt are also provided.
    Type: Grant
    Filed: May 1, 1980
    Date of Patent: June 28, 1983
    Assignee: Steelcase, Incorporated
    Inventors: Frederick S. Faiks, Charles C. Pergler, Ronald L. Whitwam, Jack R. Knoblauch, Duane M. Beukema, Kenneth W. Hozeski
  • Patent number: 4373692
    Abstract: The specification discloses a chair control in which a chair height adjustment actuator includes a handle whose position does not change relative to the tilting member of the chair control. The handle is pivotally mounted to the tiltable member and engages the end of a linkage rod pivotally mounted to the handle. The other end of the linkage rod is pivotally joined to an actuator arm which in turn is pivotally secured to the mounting member of the stationary chair control housing adjacent that point at which the mounting member is secured to a chair base of the type having a height adjustment actuator located at the top of the chair base column.
    Type: Grant
    Filed: May 1, 1980
    Date of Patent: February 15, 1983
    Assignee: Steelcase Inc.
    Inventors: Jack R. Knoblauch, Duane M. Beukema, Kenneth W. Hozeski
  • Patent number: 4324382
    Abstract: The specification discloses a compact, easy to assemble, height adjustable chair base in which a column telescopically received within a hub tube includes a spring and nut assembly located within the bottom of the column and carried on a threaded post fixedly secured and projecting upwardly within the hub tube. A spring housing is rotatably carried within the column and the top abuts against an abutment shoulder located within the column. The spring is located within the spring housing and both the spring and spring housing bear down on a washer which in turn bears down on the nut. The column includes portions extending around and below the nut, includes detent means located on the column below the nut which disengage the nut when a person sits on the chair, but which is biased upwardly towards engagement with the nut by the action of the spring when the chair is unoccupied. When the chair is unoccupied, rotation of the chair will cause the nut to rotate upwardly or downwardly on the threaded post.
    Type: Grant
    Filed: June 21, 1979
    Date of Patent: April 13, 1982
    Assignee: Steelcase Inc.
    Inventors: Duane M. Beukema, Jack R. Knoblauch