Seat slide device

Abstract

In a seat slide device applicable to an automotive vehicle, a lock mechanism includes: a lock arm disposed on an upper rail to be pivotable around a pivotal center axis; lock pawls formed on the lock arm along the elongate direction of the upper rail; lock holes formed on a lower rail and the upper rail, the lock pawls being inserted through the lock holes to lock the upper rail with respect to the lower rail; a pair of slits formed at predetermined front-and-rear positions of a side surface of the upper rail; and a bearing bracket, the bearing bracket and the lock arm being disposed within an enclosed space between the upper rail and the lower rail and including a pair of bearing portions and both ends of the lock arm and the pair of bearing portions being disposed within inner spaces defined by the pair of slits.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view of a seat slide device applicable to an automotive vehicle in a preferred embodiment according to the present invention.

FIG. 2 is a perspective view of an upper rail in the proximity of a lock arm shown in FIG. 1.

FIG. 3 is a cross sectional view of the seat slide device representing an essential part of the seat slide device in the embodiment according to the present invention.

FIGS. 4A, 4B, 4C, and 4D are a left side view, a plan view, a front view, and a bottom view of the proximity of the lock arm of the seat slide device in the preferred embodiment according to the present invention.

FIGS. 5A, 5B, and 5C are plan view of the seat slide device in the preferred embodiment according to the present invention, a top view thereof, and a side view thereof viewed from an arrow marked direction of A shown in FIG. 5B, respectively.

FIG. 6 is a comparative example of the seat slide device to the present invention representing a reference view of part of the seat slide device for explaining a height size of a lock hole formed on an upper rail.

Claims

1. A seat slide device comprising: a lower rail having a channel structure;an upper rail having a channel structure, the upper rail being slidably engaged with the lower rail in a manner to define an elongate enclosed space therebetween; anda lock mechanism including a lock arm disposed on the upper rail to be pivotable around a pivotal center axis which is approximately in parallel to an elongate direction of the upper rail, at least two lock pawls formed on the lock arm along the elongate direction of the upper rail, a plurality of lock holes formed on the lower rail and the upper rail, the lock pawls being inserted through the lock holes to lock the upper rail with respect to the lower rail, a pair of slits formed at predetermined front-and-rear positions of a side surface of the upper rail, and a bearing bracket configured to pivotably support the lock arm, the bearing bracket and the lock arm being disposed within the enclosed space between the upper rail and the lower rail and including a pair of bearing portions configured to pivotably support both ends of the lock arm via a pair of pivotal axles of the pair of bearing portions, both ends of the lock arm and the pair of bearing portions being disposed within inner spaces defined by the pair of slits.

2. The seat slide device as claimed in claim 1, wherein the pair of pivotal axles are formed through an integral forming with the pair of bearing portions along the pivotal center axis and projected from the pair of bearing portions and a pair of axial holes are formed on both ends of the lock arm, the pair of pivotal axles being fitted into the axial holes, respectively.

3. The seat slide device as claimed in claim 1, wherein the lock arm is formed of an approximately Japanese letter of shape in cross section.

4. The seat slide device as claimed in claim 2, wherein an input arm portion is integrally projected from one of both ends of the lock arm.

5. The seat slide device as claimed in claim 4, wherein the lock mechanism further includes a plate spring in an approximately Japanese letter of < shape to bias the lock arm to be pivoted in a lock direction, the plate spring having a bending portion at a center thereof contacted on a surface of the lock arm and contact portions at both ends thereof contacted on an upper side wall portion of the upper rail, the plate spring always biasing tips of the lock pawls toward the upper side wall portion of the upper rail.

6. The seat slide device as claimed in claim 5, wherein a plurality of first lock holes are formed along a downward oriented bending portion of the lower rail consecutively between stopper portions formed at front-and-rear ends of the lower rail, at least two second lock holes are formed on the upper side wall portion of the upper rail between the pair of slits, and at least two third lock holes are formed on an upward oriented bending portion of the upper rail between two latches formed at the same positions of the upper rail as the pair of slits.

7. The seat slide device as claimed in claim 6, wherein the lock pawls of the lock arm are penetrated through the first, second, and third lock holes simultaneously by means of a biasing force of the plate spring.

8. The seat slide device as claimed in claim 7, wherein the slide device further comprises a pressing portion of a handle holder that is caused to press the input arm portion of the lock arm toward a downward direction with respect to the upper rail to cause the lock pawls to be pivoted with the pair of pivotal axles as a center against the biasing force of the plate spring, thus the lock pawls being pulled from the first, second, and third lock holes to be in a lock release state.

9. The seat slide device as claimed in claim 2, wherein the bearing bracket comprises a pair of bearing bracket pieces, each being in an approximately letter L shape, one of the pair of bearing bracket pieces having a junction portion formed by an offset of the one of the pair of bearing bracket pieces in a thickness direction thereof by a board thickness, the junction having a convex portion which is fitted into a recess portion formed on the other of the pair of bearing bracket pieces to integrally form the bearing bracket.

10. The seat slide device as claimed in claim 9, wherein a pair of first attaching holes are formed on plane portions of the pair of bearing bracket pieces and a pair of second attaching holes are penetrated through an upper wall portion of the upper rail approximately adjacent to a corresponding one of the pair of the slits to couple the pair of bearing bracket pieces to a lower surface of the upper wall portion of the upper rail via the pair of first attaching holes and two rivets.

11. An assembling method of a seat slide device, comprising: providing a lower rail having a channel structure; providing an upper rail having a channel structure, the upper rail being slidably engaged with the lower rail in a manner to define an elongate enclosed space therebetween; andproviding a lock mechanism including a lock arm disposed on the upper rail to be pivotable around a pivotal center axis which is approximately in parallel to an elongate direction of the upper rail, at least two lock pawls formed on the lock arm along the elongate direction of the upper rail, a plurality of lock holes formed on the lower rail and the upper rail, the lock pawls being inserted through the lock holes to lock the upper rail with respect to the lower rail, a pair of slits formed at predetermined front-and-rear positions of a side surface of the upper rail, and a bearing bracket configured to pivotably support the lock arm, the bearing bracket and the lock arm being disposed within the enclosed space between the upper rail and the lower rail and including a pair of bearing portions configured to pivotably support both ends of the lock arm via a pair of pivotal axles of the pair of bearing portions, both ends of the lock arm and the pair of bearing portions being disposed within inner spaces defined by the pair of slits.