Longitudinal guide for a motor vehicle seat
A longitudinal guide for vehicle seats including two elongate rails, each including a lower rail, an upper rail supported on the lower rail and displaceable longitudinally, two bearing areas for guiding means, the bearing areas lying diagonally opposite to and being biased against each other, each upper rail and lower rail having an L-shaped region, if viewed in profile, formed by a base leg and an L-leg that protrudes from the base leg substantially perpendicularly, and two end regions, which adjoin the L-shaped region, each end region of the upper or lower rail together with the end region of the associated lower or upper rail forming an embracing area by mutually hooking, end regions of the upper rail forming bearing areas with opposite portions of the associated lower rail, and a plurality of balls are supported in a first bearing area on the end region having a circular arc-shaped profile.
1. A longitudinal guide for vehicle seats, comprising two elongate rails, each comprising a lower rail and an upper rail supported thereon so as to be movable in a longitudinal direction, wherein
each upper rail and each lower rail comprises an L-shaped region, if viewed in profile, and two end portions which are respectively connected to the L-shaped region,
the end portions of the respective upper rail and of the respective lower rail form diagonally opposite embracing areas under mutual interlocking,
each elongate rail comprises a first bearing area and a second bearing area for guiding means, which are biased to each other and formed by opposite end portions of the respective upper rail and portions of the associated lower rail,
the L-shaped region of the upper rail is formed by a base leg forming the uppermost portion of the upper rail and an L-leg projecting from the base leg perpendicularly, and
the L-shaped region of the lower rail is formed by a base leg forming the bottommost portion of the lower rail and an L-leg projecting from the base leg perpendicularly,
wherein
the L-leg of the lower rail is followed by a first connecting leg of the lower rail projecting obliquely outwards from the L-leg of the lower rail and by a second bearing leg of the lower rail projecting obliquely upwardly from the first connecting leg of the lower rail and outwards from the upper rail, wherein
the first bearing area is formed between an end portion of the upper rail formed as a circular arc-shaped profile and an opposite corner area of the lower rail formed on the second bearing leg of the lower rail and disposed outwards from the upper rail relative to the end portion of the upper rail formed as a circular arc-shaped profile, and
a single group of guiding means formed by a plurality of balls disposed in a row in a longitudinal direction of the two elongate rails is supported in the first bearing area, wherein
contact points of the plurality of balls at the end portion of the upper rail formed as the circular arc-shaped profile are on an opposite side of a virtual center line through the L-leg of the lower rail, if viewed from an interior space (I) of the elongate rails, or lie on said virtual center line, and
wherein the base leg of the upper rail is followed by a connecting leg of the upper rail, which is opposite to the L-leg of the upper rail and extends in parallel therewith, by a slanted connecting leg of the upper rail and by a bent portion, which is followed by the end portion of the upper rail formed as a circular arc-shaped profile,
a predetermined bending position is provided in a transition area between the connecting leg of the upper rail and the slanted connecting leg of the upper rail, and the predetermined bending position is less stiff than a curved area connecting the base leg of the upper rail and the connecting leg of the upper rail and than the bent portion.
2. The longitudinal guide as claimed in claim 1 , wherein the first connecting leg projects obliquely upwardly from the L-leg of the lower rail.
3. The longitudinal guide as claimed in claim 1 , wherein the distance between the contact points to the virtual center line is less than a material thickness (SOS) of the respective upper rail.
4. The longitudinal guide as claimed in claim 3 , wherein the contact points further lie on a virtual extension line of an outer side of the L-leg of the lower rail or lie outside of this virtual extension line, if viewed from an interior space (I) of the elongate rails.
5. The longitudinal guide as claimed in claim 4 , wherein the distance of the contact points to the virtual extension line is less than a material thickness (SOS, SUS) of the upper or lower rail.
6. The longitudinal guide as claimed in claim 4 , wherein the distance of the contact points to the virtual extension line is less than a material thickness (SOS) of the upper rail.
7. The longitudinal guide as claimed in claim 6 , wherein the contact points lie outside of the virtual extension line of an outer side of the L-leg of the lower rail, if viewed from an interior space (I) of the elongate rails, or lie on this virtual extension line.
8. The longitudinal guide as claimed in claim 7 , wherein the distance of the contact points to the virtual extension line is less than a material thickness (SOS, SUS) of the upper or lower rail.
9. The longitudinal guide as claimed in claim 1 , wherein the predetermined bending position has a smaller torsional rigidity.
10. The longitudinal guide as claimed in claim 9 , wherein the bent portion lies on the virtual center line through the L-leg of the lower rail, which projects perpendicularly from the base leg of the lower rail.
11. The longitudinal guide as claimed in claim 1 , wherein
a plurality of first rollers and a plurality of second rollers are supported in the second bearing area diagonally opposite to the first bearing area,
the plurality of first rollers are supported with a lateral play between the base leg of the lower rail and an opposite supporting leg of the upper rail extending in parallel thereto,
the plurality of second rollers are supported between an end portion of the respective upper rail, extending under an acute angle obliquely upwards from the supporting leg of the upper rail, and an opposite inclined supporting leg of the lower rail, and
the inclined supporting leg of the lower rail is formed between a connecting leg of the lower rail adjoining the base leg of the lower rail and extending vertically upwardly and an adjoined horizontal base leg of the embracing area in the end portion of the lower rail.
12. The longitudinal guide as claimed in claim 11 , wherein one or more of a corner area between the base leg of the lower rail and the L-leg of the lower rail, a transition area between the L-leg of the lower rail and the first connecting leg of the lower rail, and a transition area between the first connecting leg of the lower rail and the second bearing leg of the lower rail, is provided with an embossment formed by cold work forming to effect a higher stiffness.
13. The longitudinal guide as claimed in claim 12 , wherein the embossments are formed with an even curvature.