초록 ▼

A height adjustable mechanism for supporting a work support for vertical movement relative to a base includes a counterbalance mechanism for providing a force opposing a downward force tending to lower the work support; a lock mechanism for releasably retaining the work support in a desired vertical

A height adjustable mechanism for supporting a work support for vertical movement relative to a base includes a counterbalance mechanism for providing a force opposing a downward force tending to lower the work support; a lock mechanism for releasably retaining the work support in a desired vertical position; and a manual operator for selectively releasing the lock mechanism to permit vertical movement of the work surface, while preventing operation of the lock mechanism if the counterbalance force and the downward force are out of balance by some given extent. In the preferred construction, the lock mechanism is pivotally supported by a pin normally supported for axial sliding movement under the control of the manual operator, and the lock mechanism applies loading to the pin, when the counterbalance force substantially differs from the downward force, sufficient to constrain the pin against sliding movement, and thereby prevent release of the lock mechanism by the manual operator.

대표청구항 ▼

[ What is claimed is:] [1.] A mechanism having a base; a work surface; mounting means for mounting said work surface for vertical movement relative to said base; a counterbalance mechanism for providing a counterbalance force opposing a downward force tending to lower said work surface; a locking me

[ What is claimed is:] [1.] A mechanism having a base; a work surface; mounting means for mounting said work surface for vertical movement relative to said base; a counterbalance mechanism for providing a counterbalance force opposing a downward force tending to lower said work surface; a locking mechanism for releasably retaining said work surface in a desired vertical position, said locking mechanism including release means for releasing said locking mechanism to permit vertical movement of said work surface; and control means for selectively controlling said release means, said control means having an operator movable between locking and release positions and coupling means to couple said operator to said release means for normally effecting operation of said release means upon movement of said operator into said release position, and said locking mechanism is connected to said coupling means intermediate said operator and release means for preventing operation of said release means by said operator when said counterbalance and downward forces are out of balance by some given extent.