WO1997010971A1 - Transport system for a wound electric conductor with winding reversal by loop formation - Google Patents

Abstract

The invention relates to a transport system for a wound electric conductor for motor vehicles. Such flat coil springs are designed to provide a reliable electrical connection between the rotating steering wheel and stationary switching devices. The purpose of the invention is to provide a relatively small transport system which is easy to produce and has a relatively short flat coil spring. The invention achieves this purpose by the use of a deflecting component (11) engaging in a loop (14) and of a coil body (3) on which a part of the flat coil spring (8) is wound.

Description

Transport system for a wound electrical conductor with reversal of the winding direction by forming loops

The invention relates to a transport system for a wound up electrical conductor with reversal of the winding direction by forming loops. Such a system is particularly required for motor vehicles. The wound conductor creating a secure electrical connection between two parts of a motor vehicle (chassis-steering wheel) rotating against one another is often referred to below as the winding spring. The problem with vehicles is that a number of electrical devices, such as a horn, airbag and the like, are accommodated on the steering wheel sitting on the steering column. These devices are connected to circuits which are fixed in relation to the vehicle chassis, while the devices seated in the steering wheel perform rotary movements with the steering wheel. Because of the steering angle gearbox, the rotational movement of the steering wheel can assume considerable dimensions. In order to nevertheless create a secure electrical connection, a clock spring is provided, which is located in the vicinity of the steering column switch and is generally wound in a spiral.

Since the known coil springs can have a length of several meters, short-band systems have been proposed in which the coil spring is placed in a loop in the housing for the coil spring. For this purpose it makes sense to design the winding spring itself in the form of a band. It is important for such systems that the loop is safely guided. It should also be kept as short as possible. Another object of the invention is to reduce the installation space of the clock spring housing, in particular in its diameter. Finally, the aim of the invention is to improve the guidance of the loop end within the clock spring housing by means of targeted measures.

The invention is therefore based on a transport system for a clock spring of the type resulting from the preamble of claim 1.

In such a system, the object is achieved by the combination of features resulting from the characterizing part of claim 1.

In principle, the invention consists in providing a special deflection part which ensures good guidance of the in particular band-shaped coil spring. In addition, a coil body rotatable with the cover of the coil spring housing is provided, on which the winding tape or the wire-shaped coil spring is wound or unwound depending on the direction of rotation of the steering wheel.

A new type of system, which allows winding of the clock spring in two directions and thereby shortening the clock spring accordingly, results in an advantageous development of the invention from the features of claim 2. An improvement of the grinding guide can be achieved by the features of claim 3 , this also applies to the guide surfaces according to claim 6. Claim 4 specifies an advantageous combination of features for the mounting of the end of the coil spring. After that, the transport of the deflection part is independent of the winding direction on the coil former, and the winding spring always conveys in the same direction to the loop. By adjusting the rotational position of the cylinder body in the preferably ring-shaped coil body, the direction of extension of the winding springs from the coil body to the deflection part can be determined.

Due to the combination of features according to claim 5, the exit direction of the clock spring from the coil body is automatically set depending on its position relative to the deflecting body. This ensures particularly good guidance of the winding springs around the deflecting body.

In order to prevent the ribbon loop from rubbing directly on the winding of the bobbin and to ensure a particularly good guidance of the loop, the feature combination according to claim 6 is recommended in a further development of the invention. The leadership of the preferably ribbon-shaped winding spring can still be carried out improve the measures according to claim 7. The last-mentioned measures all serve the purpose of preventing the spring from buckling and getting tangled within the housing.

If the dimensions of the housing diameter are to be kept as small as possible, the combination of features according to claim 8 is recommended in a further development of the invention. Thereafter, two coils are provided in the housing, the winding spring being unwound from one coil and from the one during a rotary movement other coil is wound up. In order to facilitate such a winding process, the combination of features according to claim 9 is recommended in a further development of the invention the deflection part is mounted displaceably in the housing about the steering column axis and steering column direction and thus separates the two coil sections from one another. For this purpose, cylindrical jacket-shaped chamber walls can be used, which allow axial movement and also a rotary movement of the deflecting part, but fix its radial position.

The deflecting part has a particularly simple construction using the features according to claim 10, wherein the conduction band can be guided over the cutting edge. In order to simplify the assembly even further (no permanent assembly due to the symmetrical structure) and to reduce the forces necessary for the guidance, the combination of features according to claim 11 is recommended in a further development of the invention.

Theoretical considerations show that the speed of rotation of the deflection part is half that of the first coil section rotating with the housing cover. If one does not want to provide a separate gear, one must ensure that the deflection part is carried along by the cover or the coil section located on the cover, but can at the same time rotate relative to these components. These driving forces ensure that the coil sections are wound or unwound cleanly. At the same time, the force exerted by the conduction band on the leading edge produces the rotation of the deflection part. Since the deflection part should rotate in two directions and should be able to be installed depending on the position, the combination of features according to claim 11 is therefore recommended in a further development of the invention. The electrical conductors can be single strands or a plurality of strands overmolded to a round cross section with the advantage that the guide surface of the deflecting part can be comparatively narrow. But it is also particularly cheap, accordingly of the combination of features according to claim 15 to design the electrical conductor as a helical flat strip, since this means that the spring has greater rigidity and can be guided more easily. In this case, however, a correspondingly wide guideway must be provided at the cutting edge of the deflection part and there must be sufficient space to rotate the winding tape in the region of the guideway in its longitudinal axis by 90 degrees with respect to the position on the bobbin. In any case, the deflecting part must have at least the height of the minimum loop diameter at which the related conductor has a function over the entire service life according to the specification.

Another possibility for good guidance of the winding springs in the housing is shown by the combination of features according to claim 17. As a result, the loop is forcibly guided at its end by the deflecting part, so that the loop is always kept taut and the spring cannot become tangled. As a particularly simple gear, a wobble gear is proposed according to claim 18, with which a suitable reduction of the deflection part can be achieved inexpensively, which must have a lower rotational speed than the housing cover or the steering column of the handlebar.

The features according to claim 19 describe a simple construction for such a transmission. In this case, the usual involute toothing is not used for the internal toothing of the housing and the cam disk, but rather a curved toothing which ensures a smoother running and is easier to manufacture is. The toothing of the housing is formed by rotating or fixed rollers, the fixed rollers being easier to install, while the rotating rollers to ensure a lower friction of the cam disc in the housing. In order to ensure a central position of the drive wheel carrying the deflection part by the eccentrically rotating cam disc, in a further development of the invention the combination of features according to claim 20 is recommended, in which case the positive fit is to be understood as that both disks are positively connected to each other but can be sufficiently shifted against each other.

The combination of features according to claim 21 results in particularly good guidance of the coil spring, which is preferably designed as a band, but it is not necessary for the two deflecting parts to be at an angle of 180 degrees. The angular distance can also be considerably smaller.

Improved guidance of the clock spring can be achieved by the measures according to claim 23, this applies both to the configuration of the clock spring as a wire and to a band-shaped clock spring according to claim 24.

In motor vehicles, the detent which engages the turn signal switch is automatically disengaged by turning the steering wheel and thus the steering column back. Since the cover of the coil spring housing is intended to rotate with the steering column, the further development according to claim 25 is recommended as a particularly advantageous embodiment of the invention. Thereafter, the cover of the coil spring housing can be used at the same time for resetting the flasher switch.

Embodiments of the invention are explained below with reference to the drawings. In it shows Fig. La in an exploded view

Lc a first embodiment of the invention,

2a, 2b the first embodiment in assembled form,

3 shows a second embodiment of the invention,

4 shows the preferred form of the electrical line of the embodiment according to FIG. 3,

5 shows a first exemplary embodiment for a drive system of the deflection part,

6 shows a second exemplary embodiment for a drive system of the deflecting part,

7 is a sectional view of the top view of the drive system of FIG. 6,

8 to 10 exemplary embodiments for advantageous guiding of the clock spring on a drive pulley.

Fig. 1 shows a coil spring housing 1, which is fixed in the motor vehicle and the associated housing cover 2, which rotates with the steering column and thus also the steering wheel of the motor vehicle. A first coil former 3 is attached to the cover 2 in one piece, for example by casting.

The housing 1 has a substantially circular outer wall 4 with a slot-shaped outlet opening 5 which the coil spring 8 with its connector 7 is led out of the housing 1.

The second coil spring end 6 is wound around the coil former 3, while the first coil spring end 20 merges into a loop 14. The coil spring 8 rests on the bottom 9 of the housing 1, while the first coil body 3 dips into the interior of the housing. The steering column protrudes through the circular opening 10 of the coil former and is connected to the coil former and thus to the cover, so that this follows the rotational movement of the steering column.

A deflection part 11 projects from the bottom 9 of the housing 1 and merges into a web 12 in the form of a sector of a circle. The web 12 and the outer wall 4 form a receiving space 13 for the spring section 16, which is designed as a loop 14. The deflection part 11 is separated from the outer wall 4 by an arcuate slot 15, which connects the interior enclosed by the web 12 to the receiving space 13. A connector 17, which is connected to the clock spring 8, protrudes from the housing cover 2. The connector 17 follows the rotational movement of the housing cover 2. A cover 18 in the form of a circular section passes through the cover 2 and the first coil body 3. This circular section allows the insertion of the cylinder body 19 at the end 6 of the clock spring, the cylinder body 19 being rotatably mounted in the receptacle 18. The exit angle of the band-shaped coil spring 8 from the receptacle 18 is thus adjusted according to the applied forces, so that the angle can be adjusted in accordance with the resulting inhibitions and the coil spring evades them. The web 12 is connected at its end facing away from the deflection part 11 to the outer wall 4 of the housing 1, so that a closed space is created for the loop 14. there, which is partially limited by the outer wall 4 and by the web 12. The use of the clock spring 8 in the housing 1 can be seen clearly from Fig. 2a. It is particularly important that the coil spring section emerging from the recess 18 is guided via the arcuate slot 15 into the receiving space 13, where the coil spring forms a loop 14 and protrudes with its end out of the outlet opening 5. Thus, the clock spring 8 is securely guided in the receiving space 13.

A special feature of the exemplary embodiment according to FIGS. 1 and 2 is that the first end of the clock spring 6 can be guided via the receptacle 18 both to the left around the first coil former 3 and to the right around the first coil former 3, depending on the direction of rotation of the housing cover 2 It is therefore a particular advantage of the system that it is possible to have a direct transition of the clock spring from the receptacle 18 into the tubular slot 15 in the starting position of the steering column or in its zero position without a winding on in this zero position the first bobbin is wound. Only when the steering wheel is rotated by more than 360 degrees is the first end of the coil spring 6 wound either left or right with one or more layers on the first bobbin, depending on the direction of rotation of the steering wheel and thus of the housing cover 2.

In this way, the coil spring 8 can be kept particularly short, which supports a trouble-free movement of the coil spring band 8 in the receiving space 13. It is also important that when the first bobbin 3 rotates, the cylinder body 19 is rotated in the receptacle 18 such that the winding tape 8 is easily guided around the first bobbin 3 in one direction or the other, starting from the receptacle 18, and the tape is thus wound up can be. there as already explained above, the coil body 3 rotates together with the housing cover 2, while the housing including the receiving space 13 and the deflection part 11 remain stationary.

The embodiment according to FIGS. 1 and 2 can be used both for bib-shaped coil springs but particularly preferably also for band-shaped coil springs. It is also important for the invention that the guide surfaces for the clock spring are smooth and as free of friction as possible. The winding space between the first bobbin 3 and the web 12 should not be made larger than necessary, on the one hand to save space and on the other hand to prevent the winding spring from buckling as much as possible.

Fig. 3 shows a second embodiment of the invention. Here the steering column 21 is shown, with which the housing cover 22 is connected by force. The housing 23 has essentially the bottom 24 and an annular inner wall 25 which are arranged in a stationary manner. Below the housing cover 22 there is a helical (see FIG. 4) first coil section 26, while a helical second coil section 26, 27 is located directly above the bottom 24 of the housing. The two coil sections 27, 26 are connected to one another via a shawl 34 and are kept at a distance via a deflecting part 28. The deflection part essentially consists of a cut ring, the two cut edges 29, 30 being rounded and forming a guide edge for the band-shaped electrical conductor wound on two coil sections 26, 27.

The deflection part can be rotated about the longitudinal axis L and can also be displaced in the longitudinal direction of this axis. Only in radial Direction, the position of the deflecting part 28 is fixed. The deflection part is furthermore carried along or driven by the housing cover 22 or the first coil section 26.

If, for example, the cover 22 and thus the first coil section 26 rotates clockwise when viewed from above, the deflection part 28 is taken along. The deflection part rotates at half the speed of the first coil section 26 or the cover 22. The end of the first coil section runs over the loop 31 to the beginning of the second coil section. The second spool section 27 is, however, held stationary, but is provided with a winding direction which leads to the unwinding of the second spool section 27. If the first coil section 26 therefore winds up, the winding tape required for this can only be unwound from the second coil section. The deflection part is set up and arranged such that it can be rotated with little effort in the sense of the first coil section. The winding force on the first coil section therefore transports the deflection part, so that the coil spring 37 is wound tightly and at the same time the second coil section is unwound.

If the housing cover 22 is rotated in the opposite direction and the first coil section is thus unwound, the deflection part is driven via the cutting edge 30 and the first coil section is unwound while the second half of the coil is being wound up. Therefore, the conductor cable should have the lowest possible tendency to kink and the deflection part should run with low friction.

A particular advantage of the invention is that the height of the housing increases somewhat, the diameter the housing is comparatively small. This gives the possibility of inserting the present housing into the interior of the steering column switch, whereas in the known coil springs this had to be mounted outside, in particular above, the switch. In this way it is possible to attach one or more actuation projections 34 to the outer wall of the rotatable housing half 33, which can be used to switch a flasher switch or another device, the actuation of which depends on the set steering angle (for example steering angle sensors).

It had already been explained above that the speed of rotation of the deflection part deviates from that of the housing cover. The exemplary embodiment shown in FIG. 5 shows a swash gear with which the deflecting part is driven at a speed that deviates from the steering column. No. 40 shows a section of the steering column 41 which, provided with rollers, extends into the coil spring housing 42. The coil spring housing 42 is provided with fixed or rotatably arranged rollers 43, which take over the task of internal teeth. The rollers act on a cam contour 44 of a cam plate 45 which is acted upon by the eccentrically arranged rollers 46 on the steering column 41. The cam plate 45 thus has the effect of a swash plate of a wobble mechanism. The speed of rotation of the cam 45 relative to the speed of rotation of the steering column can be determined in a manner known per se by the difference in the number of rollers 43 compared to the number of curved projections on the cam 45.

Since the drive wheel 47 should rotate centrically but should not wobble, the knobs 48 on the drive wheel are smaller selected as the engagement holes 49 of the cam, which drive the drive wheel 47 via the knobs. The two deflection parts 51, 52 serve to guide the winding spring (not shown) in a manner to be described.

FIG. 6 differs only slightly from the embodiment according to FIG. 5 in that the clock spring is additionally shown as a band-shaped clock spring 53. The construction shown is very wear-free, low-noise and requires only a small installation space. Fig. 7 shows a detail of the eccentric gear in plan view, the cover 54 and other details have been omitted.

8, 9 and 10 show exemplary embodiments for the arrangement of the deflecting parts and the winding spool on the spool body. The course of the clock spring 64 is shown clearly in the three drawings 8, 9, 10. 8, 9 and 10 are self-explanatory. The arrangement of two webs 65 for guiding the winding spring 64 is particularly noteworthy in FIG. 9. The arrangement according to FIG. 8 has two loops, the ends of which are each secured against tangling by a deflection part 61, 62. The deflection parts are fixedly mounted on the drive wheel, as can be seen from FIG. 5 with regard to the deflection parts 51, 52.

10 also two deflection parts 63, 67 are provided, which are arranged in the vicinity of the exit region of the clock spring from the housing.

Claims

claims 1. Transport system for a clock spring, in which the first end of the coil spring (20) is fixed to the housing on the coil spring housing (I) and the second end of the coil spring (20) is anchored to the cover (2) of the housing which is rotatably mounted relative to the housing (1), characterized in that the coil spring (8) is deflected by about 180 degrees (II) and that the first spring section (6) located in front of the deflecting part (11) can be wound onto a substantially cylindrical first bobbin (3) which can be rotated with the cover (2) (FIG. 1). 2. Transport system according to claim 1, characterized gekennzeich¬ net that the behind the deflecting part (11) located second spring section (16) in a reversing loop (14) whose open end (20) through the outer wall (4) of the housing (1st ) occurs. 3. Transport system according to claim 2, characterized in that the loop section (16) extending from the reversal area of the loop (14) to the open end (20) of the loop is guided on the inside of the outer wall (4), the Has an essentially circular sector-shaped contour on the inside. 4. Transport system according to one of the preceding Ansprü¬ che, characterized in that the cover-side end (6) of the clock spring (8) is contained in a cylinder body (19) which is mounted on the edge of the bobbin (3) in this, the Clock spring (8) preferably radially emerges from the coil former (3). 5. Transport system according to claim 4, characterized gekennzeich¬ net that the cylinder body (19) is rotatably mounted in the coil body (3), wherein the outlet opening (18) of the coil spring (8) from the coil body (3) via a The peripheral portion of the coil body (3) extends in such a way that the coil spring (8) can emerge from the coil body (3) at an angle to the radial direction. 6. Transport system according to one of claims 1 to 5, da¬ characterized in that the housing-fixed deflection part (11) in a spool (3) circular sector surrounding web (12) merges, the other end preferably in the outer wall (4) of the housing (1) opens. 7. Transport system according to one of the preceding claims, characterized in that the part of the loop extending from the reversal area of the loop to the deflecting part (11) is supported on the outer wall of the web (12). 8. Transport system according to claim 1, characterized in that the conductor section located in the deflecting part (28) can be wound from a coil section 26 located above the deflecting part onto a substantially coaxial second coil section (27) located below the deflecting part and vice versa (Fig. 3). 9. Transport system according to claim 8, characterized gekennzeich¬ net that the deflecting part (28) in the housing (23) is concentrically rotatable and axially displaceably mounted in the housing. 10. Transport system according to claim 8 or 9, characterized gekenn¬ characterized in that the deflecting part (28) has essentially the shape of a cut in the axial direction circular ring, at least the cutting edge (29) having a semicircularly rounded guide surface for the electrical Line system (37). 11. Transport system according to claim 10, characterized gekennzeich¬ net that the two cutting edges (29,30) are symmetrical with respect to the cutting line to each other, the vertices of the two semicircular cutting edges (29,30) opposite each other at a short distance . 12. Transport system according to one of claims 8 to 11, characterized in that the deflecting part of the cover (22) or the first coil section (26) is taken in the direction of rotation. 13. Transport system according to one of claims 8 to 12, characterized in that the first coil section (26) entrains the deflection part (28) in such a way that it rotates half as fast as the housing cover (22) in its respective direction of rotation. 14. Transport system according to one of claims 8 to 13, characterized in that the electrical line system (37) is a strand having at least two wires. 15. Transport system according to one of claims 8 to 13, characterized in that the electrical line system (37) at least two in concentric chambers has lying coil sections of individual strands. 16. Transport system according to one of claims 8 to 13, characterized in that the electrical line system is a multi-core ribbon cable (37) which is helically wound in the opposite winding direction on the two coil sections (26, 27). 17. Transport system according to claim 1, characterized gekennzeich¬ net that the deflecting part (51,52) via a gear (41,42,45) reduces from the steering column (41) in its direction of rotation and thus in the direction of rotation of the housing cover (66 ) is driven. 18. Transport system according to claim 17, characterized gekennzeich¬ net that the gear (41,42,45) is a wobble gear. 19. Transport system according to claim 18, characterized gekennzeich¬ net that the steering column (41) with an eccentrically arranged roller bearing (46) is provided, which acts on a cam plate (45) or toothed disc, which with its toothed or with curves ( 44) edge is pressed against the internal toothing or the projections (43), preferably fixed rollers on the side walls of the housing (42). 20. Transport system according to one of claims 17 to 19, characterized in that a drive wheel (47) carrying the deflection part (51, 52) is positively connected (48, 49) to the cam disc (45). 21. Transport system according to one of claims 17 to 20, characterized in that the drive wheel (47) is provided with two deflecting parts (51, 52) which are preferably offset approximately 45 degrees or 180 degrees from one another on the drive wheel (47) are. 22. Transport system according to one of claims 17 to 21, characterized in that the coil spring wraps around the two deflecting parts (61,62; 63,67) one after the other in a meandering manner. 23. Transport system according to one of claims 17 to 22, characterized in that on the drive wheel (47) at least one sector-shaped guide rib (65) is provided. 24. Transport system according to one of the preceding claims, characterized in that the clock spring is a band spring. 25. Transport system according to one of the preceding Ansprü¬ che, characterized in that the housing cover (22) has an axially extending side extension (33) preferably in the form of the outer surface of a circular cylinder and that at least one radially on this outer surface extending actuation projection (34) is provided for switching the turn signal reset.