Device for adjusting the tilt of a vehicle seat by smaller increments

摘要

A hinge mechanism for a vehicle seat, allowing adjustment of the tilt of a seat backrest relative to a seat cushion. The hinge mechanism has two plates, the first plate containing base gear teeth on an edge directed inward, a set of first elements cooperating with a first control cam biased by first springs, a set of second elements cooperating with a second control cam biased by second springs, and a control hub for moving the control cams toward an unlocking position against the biasing of the first and second springs. The set of first elements have teeth offset angularly by at most a half-tooth relative to teeth of the set of second elements, thereby obtaining a small locking pitch.

主权项

1. A hinge mechanism of a motor vehicle seat, allowing adjustment of the tilt of a seat backrest relative to a seat cushion about a hinge axis, the hinge mechanism comprising:
first and second hinge plates intended to be rigidly connected to said backrest and seat cushion respectively, the first plate comprising base gear teeth on an edge directed radially inward, having N teeth spaced regularly apart at an angular pitch of 360/N degrees, a set of P subsets of toothed elements, including at least:
a first subset of one or more first elements cooperating with a first control cam biased by one or more first springs,a second subset of one or more second elements cooperating with a second control cam biased by one or more second springs, and a control hub adapted to move the first and second control cams toward an unlocking position, while the first and second springs independently bias the first and second cams toward a locking position, the first and second elements being movable at least radially, the first and second elements being guided by guides formed in the second plate, and the first and second elements comprising teeth for engaging with the base gear teeth, the first and second elements being movable between an engaged position where the teeth of the elements are engaged with the facing base gear teeth, and a disengaged position where there is no mutual engagement of the teeth, wherein the teeth of the first element(s) are offset angularly about the axis, relative to the teeth of the second element(s), by an offset substantially equal to (K+1/P) 360/N degrees, where K is an integer.