Steelcase Inc.

Jack R Knoblauch

Duane M Beukema

Kenneth W Hozeski

Charles C Pergler

Frederick S Faiks

Ronald L Whitwam

Alexander A Karrip

Donald D Korell

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.

Height adjustor for furniture

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.

Chain control locking assembly

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.

Synchrotilt chair control

The specification discloses a seat pitch adjustment assembly which a user can adjust upwardly or downwardly with basically the same applied force. A seat support is pivotally mounted with respect to a supporting assembly at one point and is joined thereto at another point through a pivot bracket. The pivot bracket is pivotally mounted to the support assembly on one pivot axis and to the seat support on a second pivot axis. The pivot bracketing includes a cylindrical wall defining at least a portion of the wall of a right circular cylinder whose axis of revolution lies on the aforesaid second pivot axis. The cylindrical wall includes at least one helically oriented slot receiving a projection from a slide slidably mounted on the seat support member whereby movement of the slide one way or the other rotates the pivot bracket about said second pivot axis and thereby changes the relative elevation of the first pivot axis with respect thereto. This in turn changes the pitch of the seat support with respect to the underlying support assembly and thereby changes the pitch of a seat mounted thereon.

Chair seat adjustment assembly

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.

Chair control with height adjustment actuator

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.

Height adjustable chair base

The specification discloses a chair control employing an open top, generally rectangular drawn cup for housing an energy storage package. An axle secured to and extending between stretchers which are secured to a tilting chair or member thereof, is journaled in the drawn cup and carries the energy storage package. Means for adjusting the preload of the energy package and reducing the likelihood of an energy package failure are provided. First and second interlocking spindle support members are provided which form a cup reinforcing and stress distributing structure roughly box-shaped in cross section. The four outside corners of the cup are strengthened by indented sidewall portions. A strengthening flange is disposed about the periphery of the cup and the axle journaled in the cup, has a relatively large diameter for distributing stress.

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Byron Center, MI, United States of America

Jack R Knoblauch