LONGITUDINAL ADJUSTMENT MECHANISM, VEHICLE SEAT

Abstract

A longitudinal adjustment mechanism for a vehicle seat may have a first rail and a second rail. The rails may engage about one another to form an inner channel. A spindle nut may be connected to the second rail and a spindle operationally connected to the spindle nut may be arranged in the inner channel. On one end of the first rail, a transmission may be driven by a motor, which may interact with the spindle. The spindle may be screwed into an internal thread of a worm gear of the transmission, and the spindle may be conjointly connected by a fixing element to the worm gear. The fixing element may be arranged coaxially to a spindle axle of the spindle and may be pressed between a front end portion of the spindle and the worm gear. A vehicle seat having the longitudinal adjustment mechanism is also provided.

Claims

1-15. (canceled)

16. A longitudinal adjustment mechanism for a vehicle seat, comprising: at least one pair of rails formed from a first rail and a second rail which is displaceable in the longitudinal direction relative to the first rail, wherein the rails alternately engage around each other forming an inner channel, wherein a spindle nut connected to the second rail and a spindle operatively connected to the spindle nut are arranged in the inner channel, wherein a gear which is drivable by a motor and interacts with the spindle is arranged at one end of the first rail, wherein the spindle is screwed by an external thread of the spindle into an internal thread of a worm wheel of the gear, and the spindle is connected by a fixing element to the worm wheel for conjoint rotation, wherein the fixing element is arranged coaxially with respect to a spindle axis of the spindle and is pressed between a front end section of the spindle and the worm wheel.

17. The longitudinal adjustment mechanism as claimed in claim 16, wherein the spindle is screwed at a front end section into the internal thread of the worm wheel of the gear.

18. The longitudinal adjustment mechanism as claimed in claim 16, wherein in response to a predetermined action of force, comprising a crash, a force from the first rail is conductable away via the gear, the spindle and the spindle nut to the second rail.

19. The longitudinal adjustment mechanism as claimed in claim 16, wherein the spindle has a thread-free section at its front end section.

20. The longitudinal adjustment mechanism as claimed in claim 16, wherein the fixing element provides a form-fitting connection between the spindle and the worm wheel.

21. The longitudinal adjustment mechanism as claimed in claim 16, wherein the fixing element provides a force-fitting connection between the spindle and the worm wheel.

22. The longitudinal adjustment mechanism as claimed in claim 16, wherein the fixing element is a bushing.

23. The longitudinal adjustment mechanism as claimed in claim 22, wherein the fixing element is a hollow-cylindrical bushing.

24. The longitudinal adjustment mechanism as claimed in claim 16, wherein the fixing element is a compression bushing.

25. The longitudinal adjustment mechanism as claimed in claim 16, wherein the spindle has a thread-free section at a rear end section.

26. The longitudinal adjustment mechanism as claimed in claim 16, wherein a rear end section of the spindle is mounted in a rotary bearing in the first rail.

27. The longitudinal adjustment mechanism as claimed in claim 26, wherein the rear end section of the spindle is mounted in the rotary bearing by a thread-free section.

28. The longitudinal adjustment mechanism as claimed in claim 16, wherein the external thread of the spindle and the internal thread of the worm wheel are configured in the form of a trapezoidal thread.

29. The longitudinal adjustment mechanism as claimed in claim 16, wherein the external thread of the spindle and the internal thread of the worm wheel are configured with two starts.

30. A vehicle seat with a longitudinal adjustment mechanism as claimed in claim 16.

Description

[0021] The invention is explained in more detail in the following text on the basis of an advantageous exemplary embodiment illustrated in the figures. The invention is not limited to this exemplary embodiment, however. In the figures:

[0022] FIG. 1: shows a vehicle seat according to the invention,

[0023] FIG. 2: shows a longitudinal section of a longitudinal adjustment mechanism according to the invention of the vehicle seat from FIG. 1,

[0024] FIG. 3: shows a detail of an enlarged illustration of FIG. 2,

[0025] FIG. 4: shows a gear holder with gear, a spindle and a fixing element in a first assembly state,

[0026] FIG. 5: shows the gear holder with gear, the spindle and the fixing element in a second assembly state, and

[0027] FIG. 6: shows the gear holder with gear, the spindle and the fixing element in a third assembly state.

[0028] A vehicle seat 1 illustrated schematically in FIG. 1 is described below using three spatial directions running perpendicular to one another. In the case of a vehicle seat 1 installed in the vehicle, a longitudinal direction x runs substantially horizontally and preferably parallel to a vehicle longitudinal direction, which corresponds to the normal direction of travel of the vehicle. A transverse direction, which runs perpendicularly with respect to the longitudinal direction x, is likewise oriented horizontally in the vehicle, and runs parallel to a vehicle transverse direction. A vertical direction z runs perpendicularly to the longitudinal direction x and perpendicularly to the transverse direction. In the case of a vehicle seat 1 installed in the vehicle, the vertical direction z runs parallel to the vertical axis of the vehicle.

[0029] The positional and directional indications used, such as for example front, rear, top and bottom, relate to a viewing direction of an occupant sitting in the vehicle seat 1 in a normal sitting position, wherein the vehicle seat 1 is installed in the vehicle, in a use position suitable for passenger transport, with an upright backrest 4, and is oriented in the conventional manner in the direction of travel. The vehicle seat 1 may however also be installed in a different orientation, for example transversely with respect to the direction of travel.

[0030] The vehicle seat 1 shown in FIG. 1 has a seat part 2 and the backrest 4 which is adjustable in its inclination relative to the seat part 2. An inclination of the backrest 4 can be adjustable, for example, by means of a latching fitting or a geared fitting. The vehicle seat 1 is mounted on a longitudinal adjustment mechanism 10 for adjusting a longitudinal seat position.

[0031] FIG. 2 shows the longitudinal adjustment mechanism 10 according to the invention of the vehicle seat 1 from FIG. 1. The longitudinal adjustment mechanism 10 has at least one pair of rails, preferably two pairs of rails. The pairs of rails are each formed from a first rail 12, in particular for connection to a seat structure, and from a second rail 14, in particular for connection to a vehicle structure. The rails 12, 14 of the pair of rails are displaceable in the longitudinal direction x relative to one another and engage alternately around one another forming an inner channel 16. A spindle nut 30 connected to the second rail 14 and a spindle 20 operatively connected to the spindle nut 30 are arranged in the inner channel 16. In the present case, the spindle nut 30 is held fixed, in particular screwed, to the second rail 14. The spindle 20 extends along a spindle axis A parallel to the longitudinal direction x.

[0032] At a front end section 20a of the spindle 20 there is arranged a gear 50 which is drivable by means of a motor (not illustrated) and which interacts with the spindle 20. The motor can be held on a motor carrier mounted between the two gears 50 of the respective pairs of rails and can drive the two gears 50 by means of a shaft, not illustrated in FIG. 2. The motor here drives in particular a worm 52 that is rotatably mounted about a worm axis of rotation and by means of which a worm wheel 54 that is rotatably mounted perpendicular to the worm axis of rotation is drivable in a predetermined reduction ratio. The worm 52 and the worm wheel 54 are preferably accommodated in a common gear housing. The worm wheel 54 has a central section 54a having an internal thread 56 and two bearing sections 54b adjoining the central section 54a parallel to the longitudinal direction x. At least the front bearing section 54b in the longitudinal direction x is configured to be thread-free.

[0033] The worm wheel 54 is provided in order to drive the spindle 20 in rotation about a spindle axis A. The gear 50 supports the front end section 20a of the spindle 20. A rear end section 20b of the spindle 20 is mounted in a rotary bearing 40 on the first rail 12.

[0034] FIG. 3 shows an illustration, enlarged in detail, of the longitudinal adjustment mechanism 10 in the region of the front end section of the spindle 20. The gear 50 is connected to the first rail 12 by means of a gear holder 60. The gear holder 60 has two limbs 62 parallel to one another. The two opposite limbs 62 are connected to one another in a manner known per se via a web 64. Each of the limbs 62 is adjoined by a fastening section 66, by means of which the gear holder 60 is held on the first rail 12. The fastening sections 66 are bent by approximately 90° with respect to their respective limbs 62. In the assembled state of the U-shaped gear holder 60, the gear 50 is received between the limbs 62.

[0035] In known devices for longitudinal seat adjustment, the fastening sections 66 usually have threaded bores which, in interaction with corresponding screws and/or threaded bolts, bring about a connection to the first rail 12. The gear holder 60 can alternatively be welded or riveted to the first rail 12.

[0036] The spindle 20 is passed through one of the two mutually parallel limbs 62 of the substantially U-shaped gear holder 60. In the present case, the spindle 20 is passed through the rear limb 62 parallel to the longitudinal direction x. At its front end section 20a, the spindle 20 is screwed into the internal thread 56 of a worm wheel 54 by means of the external thread 22 of the spindle 20. The spindle 20 is connected by means of a fixing element 58 to the worm wheel 54 for conjoint rotation.

[0037] FIG. 4 shows the front end section 20a of the spindle 20, the fixing element 58 and an assembly, formed from the gear holder 60 and the gear 50, in a first assembly state in which the spindle 20 and the fixing element 58 are not connected to the assembly. The spindle 20 has a thread-free section 24 at its front end section 20a.

[0038] FIG. 5 shows a subsequent assembly state in which the spindle 20 is passed through the rear limb 62 of the gear holder 60 parallel to the longitudinal direction x and is screwed into the internal thread 56 of the worm wheel 54 by means of the external thread 22 of the spindle 20. The spindle 20 is screwed in through the internal thread 56 of the worm wheel 54 in such a way that the thread-free section 24 of the spindle 20 protrudes through the internal thread 56 into the bearing section 54b, in the present case protruding through the latter.

[0039] FIG. 6 shows a third, in particular final, assembly state in which the spindle 20, which was previously screwed into the worm wheel 54, and the worm wheel 54 are connected to one another by means of the fixing element 58 for conjoint rotation. For this purpose, the fixing element 58 is inserted, in the present case pressed, from the front end section 20a of the spindle 20 into a previously empty region between the thread-free section 24 of the spindle 20 and the bearing section 54b of the worm wheel 50 surrounding the thread-free section 24. By pressing in the fixing element 58, the spindle 20 and the worm wheel 54 are frictionally connected to one another.

[0040] The features which are disclosed in the description above, in the claims, and in the figures may be of importance, both individually and in combination, for the implementation of the invention in its various configurations.

[0041] Although the invention has been described in detail in the figures and in the above illustration, the illustrations should be understood as being illustrative and by way of example and not as restrictive. In particular, the selection of the graphically illustrated proportions of the individual elements should not be interpreted as being required or limiting. Furthermore, the invention is in particular not limited to the exemplary embodiments discussed. Further variants of the invention and the implementation thereof are apparent to a person skilled in the art from the preceding disclosure, from the figures and from the claims.

[0042] Terms such as “comprise”, “have”, “include”, “contain” and the like used in the claims do not rule out further elements or steps. The use of the indefinite article does not rule out a plurality. A single device may perform the functions of several of the units or devices mentioned in the claims.

LIST OF REFERENCE SIGNS

[0043] 1 Vehicle seat [0044] 2 Seat part [0045] 4 Backrest [0046] 10 Longitudinal adjustment mechanism [0047] 12 First rail [0048] 14 Second rail [0049] 16 Inner channel [0050] 20 Spindle [0051] 20a Front end section (of the spindle 20) [0052] 20b Rear end section (of the spindle 20) [0053] 22 External thread [0054] 24 Thread-free section [0055] 30 Spindle nut [0056] 40 Rotary bearing [0057] 50 Gear [0058] 52 Worm [0059] 54 Worm wheel [0060] 54a Central section [0061] 54b Bearing section [0062] 56 Internal thread [0063] 58 Fixing element [0064] 60 Gear holder [0065] 62 Limb [0066] 64 Web [0067] 66 Connecting portion [0068] A Spindle axis (of the spindle 20) [0069] x Longitudinal direction [0070] z Vertical direction