Seat adjusting mechanism

Abstract

A manually operable four-way seat adjuster mechanism comprising a horizontally movable carriage assembly, and a seat assembly connected to said carriage by bell-cranks. The bell-cranks at each side of the carriage assembly are connected by links, at least one of which in turn is provided with notches, and a correspondingly notched latch lever retains the link in adjusted latched position. Torsion bars interconnect bell-cranks at opposite sides of the carriage, each comprising a rod extending through a closely fitted tube, the ends of which are fixed to the bell-cranks. The ends of the rods are flattened and fixed to opposite sides of the carriage. A strong balance spring assists the bell-cranks, and the geometry is such as to provide a substantially uniform lifting torque to the seat throughout its range of adjustment.

Description

Claims

1. A manually operable four-way vehicle seat adjusting mechanism comprising a pair of stationary tracks, elongated carriages movable longitudinally of said tracks, rigid torsion bars having cylindrical intermediate portions and flattened end portions fixedly connected at the flattened end portions to said carriages to provide a rigid carriage assembly, torsion tubes mounted on the intermediate portions of said bars and journaled thereby for rotation thereon, lifting bell-cranks fixed to said tubes adjacent their ends, links extending longitudinally between the bell-cranks at each side of said mechanism, and a seat frame including longitudinally extending rigid frame bars pivotally connected at their ends to the bell-cranks at each side of the mechanism.

2. A mechanism as defined in claim 1, in which the flattened end of said torsion bars have a width greater than the diameter of said torsion tubes, and in which the flattened end portions are welded to said carriage bars.

3. A mechanism as defined in claim 1, which comprises a lifting balance spring connected to one of said bell-cranks to bias said bell-crank in a direction to raise the seat frame connected thereto, said spring arranged to apply its maximum biasing force when said seat frame is in its lowermost position, said bell-cranks arranged to have lever arms applying increasing mechanical advantage as the seat is initially moved upwards from the lowermost position.

4. A mechanism as defined in claim 1, comprising a rigid link connecting the bell-cranks at one side of said mechanism, a series of latching teeth on a vertical side of said link, a latch lever pivoted to said carriage assembly having vertically extending teeth engageable with the teeth on said link to maintain said link and hence the bell-cranks connected thereto at a selected position of adjustment.

5. A mechanism as defined in claim 4, comprising resilient biasing means urging said latch lever in a direction to maintain the teeth of said link and latch lever in latching engagement.

6. A manually operable four-way vehicle seat adjusting mechanism comprising a pair of stationary tracks, a carriage assembly comprising a pair of lifting bell-cranks pivoted to said carriage at each side thereof, a seat assembly comprising an elongated carriage bar pivotally connected at its ends to said pair of bell-cranks, a link pivotally connected at its ends to similar pivot connections on said pair of bell-cranks, said link having a longitudinally extending series of latch teeth thereon, a latch lever pivoted to said carriage assembly having a series of latch teeth engageable with selected portions of the series of latch teeth on said link, and resilient means connected to said latch lever and biasing said latch in a direction to engage the teeth thereon with a selected portion of the teeth on said link.

7. A mechanism as defined in claim 6, in which the teeth on said link are arranged with their teeth on a curved pitch line to provide for full tooth engagement at different heights of the link from said carriage assembly.

8. A mechanism as defined in claim 6, in which the teeth on said link are on the underside thereof, and the teeth of said latch lever are on the upper side thereof.