ADJUSTING MECHANISM

1. Field of the invention

The present invention relates to an adjusting mechanism for the adjustment of at least one Bowden cable with a Bowden cable sheath and a cable of a Bowden cable. Such an adjusting mechanism is for example used for the adjustment of a lumbar support within motor-vehicle seats.

2. Prior art

In more exclusive motor vehicle seats, the backrest of the seat and/or the seat cushioning can be adapted to the user. To this end, e.g. so-called lumbar supports are used, by which the curvature of the backrest can be adjusted. The adjustment of such a lumbar support preferably is done via Bowden cables, which are actuated by means of an adjusting mechanism.

The adjusting mechanism itself can be e.g. driven electrically or manually in that e.g. the user rotates a rotating knob. In the prior art, different kinds of manual adjusting mechanisms are known.

So, e.g. the US 6,520,580 Bl shows an adjusting mechanism for the adjustment of a Bowden cable which is actuated by means of a hand wheel. The hand wheel is connected with a hollow-cylindrically shaped nut, which consists of two halves. Into this nut, a screw is screwed, at which a cable of the Bowden cable is connected. The Bowden cable sheath is connected to a stationary housing. By means of a rotation of the hand wheel, likewise the nut is rotated, whereby the screw is

screwed into or out of the nut. The screw is mounted within the housing axially displaceable and rotatably fixed. By means of a displacement of the screw, the cable of the Bowden cable is tightened or released and thereby the lumbar support is adjusted.

A further adjusting mechanism for the adjustment of Bowden cables is shown in the WO 99/65730. By means of this adjusting mechanism, it is possible to respectively adjust two Bowden cables independently from each other. To this end, two spindles with respectively two threaded portions are provided which comprise an opposite sense of rotation. Onto these two portions, respectively one corresponding nut is arranged, wherein one nut is connected with a Bowden cable sheath and the other nut is connected with a cable of the Bowden cable. By means of a rotation of the spindle, the two nuts move away from each other, whereby the Bowden cable is tightened or they move to each other, whereby the Bowden cable is re- leased.

At the manufacturing of motor vehicle seats, there is the tendency to design the backrest of the seat particularly slim, since then the interior of the motor vehicle is particularly well-used. Adjusting mechanisms according to the prior art, however, require a significant space, such that no lumbar supports or the like could be mounted within particularly slim backrests.

Thereby, the axial length of the adjusting mechanism according to the prior art was particularly the limiting factor. The usual manual adjusting mechanisms are arranged at a side of a backrest frame and in general extend horizontally into the interior of the backrest. The backrest, however, usually is concavely curved such that an usual adjusting mechanism would extend out of the lateral cushioning of slim backrests, which, of course, cannot be tolerated.

It is therefore one problem of the present invention to provide an adjusting mechanism, which is designed particularly space-saving and particularly comprises a small axial length.

Thereby, an adjusting mechanism should be provided which can be integrated into particularly slim backrests of motor-vehicle seats. Further, an adjusting mechanism should be provided, which works particularly reliable, comprises of only a few components and which can be cost-efficiently manufactured and mounted.

Further, an adjusting mechanism should be provided, by means of which multiple Bowden cables can be adjusted. A further problem of the present invention is to provide an adjusting mechanism which works reliably via an exactly defined adjusting range and excludes mal-operations although it has compact dimensions.

3. Summary of the invention

The above-mentioned problems are solved by an adjusting mechanism according to claim 1 , as well as of a method for the assembly of an adjusting mechanism according to claim 10.

Particularly, the above-mentioned problems are solved by an adjusting mechanism for adjustment of at least one Bowden cable with a Bowden cable sheath and a cable of a Bowden cable, comprising an axially fixed and rotatably supported spindle with only one outer thread, only one axially displaceably and rotatably fixed supported nut with an inner thread, wherein the nut comprises an axial total length which is shorter than the axial length of the outer thread of the spindle, and the nut is completely screwed onto the outer thread of the spindle.

Since the nut comprises an axial total length which is shorter than the axial length of the spindle and only one axial displaceable and rotatably fixed supported nut is provided, a particularly compact adjusting mechanism is provided, which is par-

ticularly short in its axial length, which can also be mounted in particularly slim backrests of seats. Thereby, it is possible to provide such backrests of seats with lumbar supports or the like.

Due to the reduction of the number of components, further a particularly reliably working mechanism results which can further be cost-efficiently manufactured.

In a first embodiment the nut comprises at least one receptacle at its lateral outer side for mounting an end of the Bowden cable, and the adjusting mechanism comprises at least one stationary arranged receptacle for mounting an end of the Bowden cable sheath. Thereby, a connection of the at least one Bowden cable is provided, which has a particular positive effect on the axial total length of the adjusting mechanism.

Preferably, the spindle comprises at a first end thereof an end stop, which cooperates with a corresponding first end stop of the nut, to prevent a rotation of the spindle in a first rotational direction, if the spindle is located at a first end position. With such end stops at the end of the spindle respectively at the nut, the adjusting mechanism comprises an exactly-defined end position at which the spindle cannot be rotated any further. Thereby, the user receives a clear feedback that the end of the adjustment range is reached and a jamming or overloading of the adjustment mechanism is prevented.

In a further preferred embodiment, the adjusting mechanism further comprises an end stop ring which can be rigidly connected with the spindle and which can rotate together with the spindle, wherein the end stop ring cooperates with a second end stop of the nut, to prevent a rotation of the spindle in a second rotational direction, if the nut is located at a second end position. By means of the end stop ring and a second end stop at the nut, also a defined end stop is provided for the second end position of the nut on the spindle, such that also in this rotational direction an overloading or a jamming of the adjusting mechanism is excluded.

Thereby, the user also in this adjusting direction receives a clear feedback that the end of the adjusting range is reached. Thereby, the reliability of the adjusting mechanism is increased.

In a further preferred embodiment, the first and/or the second end stop of the nut comprises a stop face, a surface normal thereof is directed essentially tangentially oriented to the spindle. By means of the tangential orientation of the surface normal of the stop face the latter is oriented such that it reliably prevents a further rotation of the spindle, such that the nut cannot jam with respect to the spindle and/or with respect to the end stop ring.

In a further preferred embodiment, the adjusting mechanism is suitable to simultaneously actuate two Bowden cables. Although the adjusting mechanism has compact dimensions due to the special structure it is possible to actuate also two Bowden cables, as it could be necessary for particular applications in motor- vehicle seats.

In a further preferred embodiment, the adjusting mechanism further comprises a housing for supporting of the nut and of a second end of the spindle, and a hous- ing lid for connecting of the Bowden cable sheath and for supporting of the first end of the spindle. The adjusting mechanism is enclosed by a two-piece housing, which simultaneously also acts for supporting of the nut, as well as of the spindle. Thereby, the adjusting mechanism obtains a particularly rigid structure and can be cost-efficiently manufactured due to the few components.

In a further preferred embodiment, the housing lid is connected to the housing by means of clips. Thereby, the adjusting mechanism can very fast and easily be manually assembled or disassembled, without the need for particular tools or fastening means.

In a further preferred embodiment, the housing comprising at its inner side axially extending slots, into which corresponding projections at the outer side of the nut engage to prevent a rotation of the nut with respect to the housing. By the provision of slots within the housing, respectively corresponding projections at the outer side of the nut, a rotation of the nut is reliably prevented and the nut is axially displaceably supported within the housing. The projections together with the slots form tangentially oriented support faces, with respect to the spindle, which reliably prevent a rotation of the nut without of radial forces interfere with the interior of the housing, as it is for example often the case at the prior art. Thereby, a deformation of the housing is prevented and thereby a jamming of the adjusting mechanism.

The above-mentioned problems are also solved by a method for the assembly of an adjusting mechanism, as it is described above, comprising the following steps in the given sequence:

a) screwing the nut onto the outer thread of the spindle via the second end of the spindle; and

b) slipping the end stop ring onto the spindle via the second end of the spindle.

By means of this method, an adjusting mechanism is manufactured in a particularly simple way, which is provided with exactly defined end stops for both adjusting directions, which reliably prevents a rotation of the spindle exceeding these end stops. Since the end stop ring must only be slipped onto the spindle after the screwing of the nut from the same side, the method can particularly simply be performed manually as well as automated.

Further preferred embodiments result from the subclaims.

4. Short description of the drawings

In the following, preferred embodiments of the invention are described by means of the drawings. In which shows:

Fig. 1 a three-dimensional view of a preferred embodiment of an adjusting mechanism according to the invention in assembled condition from the front side;

Fig. 2 a three-dimensional view of the adjusting mechanism of fig. 1 from the backside;

Fig. 3 an elongational view from the bottom side of the adjusting mechanism of fig. 1 with connected Bowden cables;

Fig. 4 a three-dimensional view of the interior components of the adjusting mechanism of Fig. 1;

Fig. 5 A a three-dimensional explosionary view of the components of the adjust- ing mechanism of Fig. 1 and two Bowden cables;

Fig. 5B a three-dimensional explosionary view of the components of an adjusting mechanism of Fig. 1 ; and

Fig. 6 an elongational view from the backside of the adjusting mechanism of fig. 1 , wherein the housing lid was removed.

5. Description of the preferred embodiments

In the following, preferred embodiments are described in detail with reference to the figures.

Fig. 1 shows a preferred embodiment of an adjusting mechanism 1 for the adjustment of Bowden cables 70, which is preferably mounted within the backrest of a motor-vehicle seat at the frame of the backrest. To this end, the adjusting mechanism 1 comprises a housing 10 with three mounting flaps 13, by which the adjust- ing mechanism 1 can be mounted at the frame of the backrest (not shown) by means of screws, rivets, clips or in another way.

The housing 10 is closed at its back end by a housing lid 50. The housing lid 50 is mounted at the housing 10 by means of three clips 12, as shown in fig. 1 and fig. 2. To this end, three corresponding windows 54 are formed into the housing lid 50.

The adjusting mechanism 1 further comprises a spindle 30, a front end 36 thereof axially extends from the adjusting mechanism 1 and is provided with an outer toothing. Onto this front end, a hand wheel or the like (not shown) can be slipped on, for the manual actuation of the adjusting mechanism 1 by the user of the motor vehicle.

As shown in fig. 3, the adjusting mechanism 1 acts for actuating two Bowden ca- bles 70, which each comprise a Bowden cable sheath 72 and a cable 74 of the

Bowden cable. By means of the actuation, the cable 74 of the Bowden cable is displaced with respect to the Bowden cable sheath 72, whereby the cable 74 of the

Bowden cable is tightened or released. For the connection of the Bowden cable sheath 72, hollow-cylindrically shaped receptacles 56 are arranged at the housing lid 50, which comprise slots for the introduction of the cable 74 of the Bowden cable 70.

Fig. 3 shows the adjusting mechanism 1 from the open side. The spindle 30 is provided with an outer thread 32 and rotatably supported within the housing 10 and the housing lid 50. For the support in the housing lid 50, the spindle 30 com- prises a first cylinder-shaped end 35, which is supported within a corresponding bore 52 (cf. fig. 5B) within the housing lid 50.

The adjusting mechanism 1 further comprises a nut 40, which comprises an inner thread 42 and which is screwed onto the outer thread 32 of the spindle 30. The nut 40 is completely screwed onto the outer thread 32 of the spindle 30, such that all threads of its inner thread 42 are always in contact with the threads of the outer thread 32 of the spindle 30. The nut 40 further comprises two projections 48 at its upper outer side, as shown in fig. 4 and fig. 6, which engage corresponding axially extending slots 11 within housing 10. Thereby, the nut 40 is axially displaceably and rotatably fixedly supported within housing 10.

By means of a rotation of the spindle 30 in a rotational direction 60 or 62, the nut 40 can be axially displaced between its first end position, as shown in fig. 3, and its second end position, as shown in fig. 4. Due to the shape of the projections 48, a jamming of the nut 40 within the housing 10 is prevented.

At its lateral underside, the nut 40 comprises two receptacles 49 which act for mounting of one end 76 of the cable 74 of the Bowden cable, respectively. For a connection within the nut 40, the ends 76 are provided with nipples or the like and hooked into the receptacles 49. Such that the Bowden cables 70 can easily be mounted at the adjusting mechanism 1, the housing 10 and the housing lid 50 are open at their under side and the receptacles 50 and 49 are slotted in order to introduce the cables 74 of the Bowden cables.

The outer thread 32 of the spindle 30 has an axial length Is which is larger than the axial length IN of the nut 40 by a desired adjusting range. The adjusting range of the adjusting mechanism 1 therefore corresponds to the length Is - I _N -

Since the total length IN of the nut 40 is shorter than the axial length Is of the outer thread 32, and the end 76 of the Bowden cable 74 is connected at the outer side of the nut 40, the adjusting mechanism 1 comprises a particularly compact shape. In particular, the axial length of the adjusting mechanism 1 , which is located within the seat frame (approximately from a flange 15 up to the receptacles 56), is par- ticularly short. Thereby, the adjusting mechanism 1 can also be mounted within motor-vehicle seats which are very slim and which particularly comprise only narrow lateral portions.

As it is shown in fig. 4 and fig. 6 at the first end 35 of the spindle 30, an end stop 34 is provided which cooperates with a corresponding end stop 44 of the nut 40, to prevent a rotation of the spindle 30 in a first rotational direction 60, if the nut 30 is located at a first end position, which is shown in fig. 3. At this first end position of the nut 40, the Bowden cables 70 are released to its most extent. To prevent an over- winding of the spindle 30, which would have the result that the nut 40 would release the housing lid 50 from the housing 10 or would lead to a jamming of the adjusting mechanism 1 , the stop face 45 comes into contact with a corresponding face of the end stop 34 of the spindle 30, such that the spindle 30 cannot be moved further in rotational direction 60. Thereby, it is excluded that the nut 40 presses against the housing lid 50 and could jam.

In order to guarantee the same for the second end position of the nut 40, an end stop ring 20 is slipped on the spindle 30 as shown in fig. 4, which is rigidly connected with spindle 30. To this end, the end stop ring 20 comprises inner recesses 24, which engage corresponding projections 37 (cf. fig. 5B) such that the end stop ring 20 rotates together with spindle 30.

The end stop ring 20 is provided with an end stop 22, which cooperates with a second end stop 46 of the nut 40, to prevent a rotation of spindle 30 in the second rotational direction 62, if the nut 40 is located at its second end position, as it is shown in fig. 4. Due to the provision of the end stop ring 20 and the end stop 46 at the nut 40, also a rotation of the nut 40 exceeding the second end position is prevented. Thereby, a jamming of the nut 40 with the housing 10 is also not possible for the second rotational direction 62.

As shown in fig. 4 and fig. 6, the surface normal N of the stop faces 45, 47 are arranged essentially tangentially to the spindle 30, such that they abut planar with the corresponding stop faces of the end stop 34 or the end stop 22 and a jamming is also excluded at these locations.

Additionally, the user receives a clear feedback that the corresponding end of the adjustment range is reached by the provision of the end stops 22, 34, 44, 46. Thereby, a damaging or a jamming of the adjustment mechanism 1 due to overwinding of the end positions is effectively prevented.

The adjusting mechanism 1 can be manually be mounted in an easy way. To this end, preferably no tools are necessary. Of course, the assembly procedure can also be automated in a simple way. The single components of the adjustment mechanism 1 are assembled in the sequence as is shown in figs. 5A and 5B.

Initially, the nut 40 is screwed onto the outer thread 32 of the spindle 30, respec- tively the spindle 30 is screwed into the nut 40. After that, the end stop ring 20 is slipped onto the spindle 30 such that the projections 37 engage within the recesses 24. Then, the spindle 30 together with the nut 40 and the end stop ring 20 is introduced into the housing 10, such that the projections 48 of the nut 40 engage within the corresponding slots 11. After that, the housing Hd 50 is clipped onto the hous- ing 10. Thereby, the adjustment mechanism 1 is completely assembled.

Due to the simple structure of the adjusting mechanism 1 it can also be easily disassembled, if this would be necessary for service or repair.

Through the slotted receptacles 56 for the ends 73 of the Bowden cable sheath 72 as well as through the slotted receptacles 49 for the ends 76 of the cables 74 of the Bowden cable, the Bowden cables 70 can easily be hooked into the adjusting mechanism 1, as shown in fig. 3.

AU components of the adjusting mechanism 1 are preferably manufactured out of a plastic material, preferably out of polyamide PA6.6 with a corresponding fiber glass amount of preferably 10%. Thereby, the adjusting mechanism 1 is particularly light-weighted, however, very rugged and reliable.

List of reference signs

1 adjusting mechanism

10 housing

11 slots

12 clips

13 mounting flaps

15 flange

20 end stop ring

22 end stop

24 recesses

30 spindle

32 outer thread

34 end stop

35 first end

36 second end

37 projections

40 nut

42 inner thread

44 first end stop

46 second end stop

45, 47 stop faces

48 projections

50 housing lid

52 spindle support

54 window

56 receptacles for Bowden cable sheath

60 first rotational direction of spindle

62 second rotational direction of spindle

70 Bowden cables

72 Bowden cable sheath

73 end of Bowden cable sheath

74 cable of Bowden cable

76 end of cable of Bowden cable