Fitting for a vehicle seat

Patent metadata

Field	Value
Publication number	US-8931843-B2
Application number	US-201013375314-A
Country	US
Kind code	B2
Filing date	Aug 20, 2010
Priority date	Aug 28, 2009
Publication date	Jan 13, 2015
Grant date	Jan 13, 2015

Abstract

A fitting ( 10 ), in particular for a motor vehicle seat, having a first fitting part ( 11 ), on which a gear rim ( 17 ) is formed and a second fitting part ( 12 ) on which a gearwheel ( 16 ) is formed. The gearwheel meshes with the gear rim ( 17 ), whereby the two fitting parts ( 11, 12 ) are in geared connection with each other. The fitting also has a rotatably mounted, revolving eccentric driven by a driving element for driving a relative rolling motion of gearwheel ( 16 ) and gear rim ( 17 ). During this rolling motion a tooth flank ( 16 d ) of a tooth ( 16 a ) of the gearwheel ( 16 ) rests against a tooth flank ( 17 d ) of a tooth ( 17 a ) of the gear rim ( 17 ) at a contact point (K). The tooth flanks ( 16 d, 17 d ) of the teeth ( 16 a, 17 a ) of the gearwheel ( 16 ) and gear rim ( 17 ) resting against each other at the contact point (K) each follow the course of a portion of a respective logarithmic spiral.

First claim

The invention claimed is:

1. A fitting for a motor vehicle seat, the fitting comprising:
a first fitting part on which is formed a toothed ring;
a second fitting part on which is formed a toothed wheel which meshes with the toothed ring, as a result of which the two fitting parts are in gear connection with each other;
a rotatably supported circumferential eccentric; and
a driver, the eccentric being driven by the driver for driving a relative rolling movement of the toothed wheel and the toothed ring, wherein, during this rolling movement at one contact point a tooth flank of a tooth of the toothed wheel bears against a tooth flank of a tooth of the toothed ring, wherein the tooth flanks of the teeth of the toothed wheel and the tooth flanks of the teeth of the toothed ring which bear against each other at the contact point, follow the course of a section of one logarithmic spiral each, wherein an eccentricity is provided, defined as a distance between a center point of the toothed ring and a center point of the toothed wheel, wherein, with respect to the center point of the toothed wheel, the contact point is at an angle with respect to an extension of the eccentricity, said angle being 10° to 55°, wherein a contact force in the contact point can circulate almost uniformly in a defined direction and with a defined lever arm.

2. A fitting according to claim 1 , wherein an arc length of at least one tooth flank at least corresponds to a partition angle of one of the toothed wheel and the toothed ring.

3. A fitting according to claim 1 , wherein, with at least one of the logarithmic spirals, an asymptotic point is on a straight line connecting the contact point and one of a center point of the toothed wheel and a center point of the toothed ring.

4. A fitting according to claim 1 , wherein the teeth of the toothed wheel and/or the toothed ring, in a section of the toothed flanks, have a width which is bigger radially outwardly than radially inwardly.

5. A fitting according to claim 4 , wherein the teeth of the toothed wheel and/or the toothed ring are approximately trapezoidal.

6. A fitting according to claim 1 , wherein, with the teeth of the toothed wheel and the toothed ring bearing against one another at the contact point, a tooth tip of the tooth of the toothed ring runs—at least in sections—equidistantly to an envelope which is defined by trajectories of edges of the tooth tips of the toothed wheel during a complete rotation of the toothed wheel.

7. A fitting according to claim 1 , wherein the toothed wheel and the toothed ring bear against one another simultaneously at two contact points.

8. A fitting according to claim 1 , wherein the contact force at the contact point is at an angle to a line connecting the center point of the toothed wheel and the contact point.

9. A fitting according to claim 8 , wherein the angle of the contact force is 70° to 110°.

10. A vehicle seat comprising:
a seat part;
a backrest; and
a fitting, the inclination of the backrest being adjusted by means of the fitting, the fitting comprising:
a first fitting part having a toothed ring;
a second fitting part having a toothed wheel which meshes with the toothed ring, as a result of which the first fitting part and the second fitting part are in gear connection with each other;
a rotatably supported circumferential eccentric; and
a driver, the eccentric being driven by the driver for driving a relative rolling movement of the toothed wheel and the toothed ring, wherein, during this rolling movement, at a contact point, a tooth flank of a tooth of the toothed wheel bears against a tooth flank of a tooth of the toothed ring, wherein the tooth flanks of the teeth of the toothed wheel and the tooth flanks of the teeth of the toothed ring, which bear against each other at the contact point, each follow the course of a section of one logarithmic spiral, wherein an eccentricity is provided, defined as a distance between a center point of the toothed ring and a center point of the toothed wheel, wherein, with respect to the center point of the toothed wheel, the contact point is at an angle with respect to an extension of the eccentricity, said angle being 10° to 55°, wherein a contact force in the contact point can circulate almost uniformly in a defined direction and with a defined lever arm.

11. A vehicle according to claim 10 , wherein an arc length of at least one tooth flank at least corresponds to a partition angle of one of the toothed wheel and the toothed ring.

12. A vehicle according to claim 10 , wherein, with at least one of the logarithmic spiral followed by the tooth flanks of the teeth of the toothed wheel and the tooth flanks of the teeth of the toothed ring, an asymptotic point is on a straight line connecting the contact point and one of a center point of the toothed wheel and a center point of the toothed ring.

13. A vehicle according to claim 10 , wherein the teeth of the toothed wheel and/or the toothed ring, in a section of the toothed flanks, have a width which is bigger radially outwardly than radially inwardly.

14. A vehicle according to claim 10 , wherein the teeth of the toothed wheel and the toothed ring bear against one another at the contact point such that a tooth tip of the tooth of the toothed ring runs—at least in sections—equidistantly to an envelope which is defined by trajectories of edges of the tooth tips of the toothed wheel during a complete rotation of the toothed wheel.

15. A vehicle according to one of the claim 10 , wherein:
the contact force at the contact point is at an angle to a line connecting the center point of the toothed wheel and the contact point of between 70° to 110°.

Assignees

• SCHüLER ROLF
• Bossmanns Bernd
• Kalmus Karsten
• Thiel Peter
• Johnson Controls Components Gmbh & Co Kg

Inventors

• SCHüLER ROLF
• Bossmanns Bernd
• Kalmus Karsten
• Thiel Peter

Classifications

• F16H2055/0893

  for parallel shaft arrangement of toothed members · CPC title

• B60N2/2252 Primary

  in which the central axis of the gearing lies inside the periphery of an orbital gear, e.g. one gear without sun gear · CPC title

• F16H1/32

  in which the central axis of the gearing lies inside the periphery of an orbital gear · CPC title

• B60N2/225

  by cycloidal or planetary mechanisms · CPC title

• B60N2/22

  the back-rest being adjustable {(B60N2/2878 takes precedence)} · CPC title