Drive cable and method of production

Abstract

A drive cable for actuating a vehicle element movable relative to a vehicle body is provided, the drive cable having a cable body having a cable core around which a coil following a helical line is coiled, the coil serving to engage with a gear wheel, the cable body being provided with a cable sheath. The cable sheath is glued to the coil.

Claims

1. A drive cable for actuating a vehicle element movable relative to a vehicle body, the drive cable comprising: a cable body having a flexible cable core around which a coil following a helical line is coiled, the coil serving to engage with a gear wheel, the cable body being provided with a cable sheath, wherein the cable sheath is glued to the coil, and the cable sheath comprises a cover layer and an adhesive layer, the adhesive layer being glued to the coil.

2. The drive cable according to claim 1, wherein the cable sheath, the coil and the cable core define a cavity which follows a helical line, and the cable sheath has a wrinkle-free surface on its side facing away from the cable core when viewed in the longitudinal direction of the cable.

3. The drive cable according to claim 1, wherein the cable body is provided with a plastic coat which forms a surface of contact with the cable sheath.

4. The drive cable according to claim 3, wherein the plastic coat is made of a polyamide.

5. The drive cable according to claim 3, wherein the plastic coat has a flattened portion for enlarging the surface of contact at the circumference of the coil.

6. The drive cable according to claim 1, wherein the cable sheath comprises a layer made of a polyamide.

7. The drive cable according to claim 1, wherein the cable sheath has ribs extending in the longitudinal direction of the cable at its circumferential surface.

8. A method for producing the drive cable of claim 1, the method comprising: providing a cable body which comprises a flexible cable core provided with a coil following a helical line; introducing the cable body into an extrusion die; and extruding a plastic tube by means of the extrusion die and gluing the plastic tube to the coil of the cable body to form a cable sheath surrounding the cable body.

9. The method according to claim 8, wherein the step of extruding the plastic tube comprises coextruding a cover layer and an adhesive layer, and gluing the adhesive layer to the coil.

10. The method according to claim 8, further comprising the step of providing the cable body with a plastic coat.

11. The method according to claim 10, further comprising the step of heating the cable body before the step of introducing the cable body into the extrusion die.

12. The method according to claim 10, further comprising the step of flattening the plastic coat in the area of the coil to enlarge the surface of contact between the plastic tube and the plastic coat before the plastic tube is applied.

13. The method according to claim 8, further comprising the step of cooling the plastic tube after having been applied to the cable body by means of a calibration device in such a manner that its diameter is wrinkle-free and stays constant throughout in the longitudinal direction of the drive cable.

14. The method according to claim 13, wherein the calibration device is a vacuum calibration device.

15. The method according to claim 13, wherein the calibration device comprises a cooling basin and further comprises the step of pulling the cable body provided with the plastic tube through the cooling basin.

Description

(1) Examples of drive cables according to the invention and an example of an installation for producing a drive cable according to the invention are illustrated in a schematically simplified manner in the drawing and will be explained in more detail in the following description.

(2) FIG. 1 is a schematic top view of a vehicle roof with a drive unit for a movable lid element;

(3) FIG. 2 is a perspective view of a drive cable according to the invention together with a drive pinion;

(4) FIG. 3 is a perspective view of a first embodiment of a drive cable according to the invention;

(5) FIG. 4 is a side view of the drive cable of FIG. 3;

(6) FIG. 5 is a longitudinal section through the drive cable of FIG. 3;

(7) FIG. 6 is a section through the drive cable of FIG. 4 along line VI-VI in

(8) FIG. 4;

(9) FIG. 7 is an enlarged view of area VII in FIG. 6;

(10) FIG. 8 is a perspective view of a second embodiment of a drive cable according to the invention;

(11) FIG. 9 is a side view of the drive cable of FIG. 8;

(12) FIG. 10 is a longitudinal section through the drive cable of FIG. 8;

(13) FIG. 11 is a section through the drive cable of FIG. 8 along line XI-XI in FIG. 9;

(14) FIG. 12 is an enlarged view of the area XII in FIG. 11;

(15) FIG. 13 is a perspective view of a third embodiment of a drive cable according to the invention;

(16) FIG. 14 is a side view of the drive cable of FIG. 13;

(17) FIG. 15 is a longitudinal section through the drive cable of FIG. 13;

(18) FIG. 16 is a cross-section through the drive cable of FIG. 13 along line XVI-XVI in FIG. 14;

(19) FIG. 17 is an enlarged view of area XVII in FIG. 16;

(20) FIG. 18 is a perspective view of a fourth embodiment of a drive cable according to the invention;

(21) FIG. 19 is a side view of the drive cable of FIG. 18;

(22) FIG. 20 is a longitudinal section through the drive cable of FIG. 18;

(23) FIG. 21 is a cross-section through the drive cable of FIG. 18 along line XXI-XXI in FIG. 19;

(24) FIG. 22 is an enlarged view of area XXII in FIG. 21; and

(25) FIG. 23 is a schematic illustration of an installation for producing a drive cable according to the invention.

(26) In FIG. 1, a vehicle roof 10 of a passenger vehicle not illustrated otherwise is shown, vehicle roof 10 having a roof opening 12 which can be selectively closed or at least partially opened by means of a lid element 14. Lid element 14 thus constitutes a vehicle element that is movable relative to the vehicle body.

(27) In order for lid element 14 to be adjustable, it is connected to a kinematic system which has a drive slide 16A, 16B on either side of a vertical longitudinal center plane of the roof, each drive slide 16A, 16B being guided in a respective guide rail 18A, 18B extending in the longitudinal direction of the roof.

(28) A compressively stiff drive cable 20 is connected to each of drive slides 16A and 16B. Drive cables 20 are routed toward a shared drive motor 22 via respective guide tubes or cable ducts and are engaged with a drive pinion 24 thereof. The engagement of the teeth of drive pinion 24 in one of drive cables 20 is illustrated in FIG. 2 independent of the other aforementioned components.

(29) Drive cables 20 can be configured according to the embodiments illustrated in FIGS. 3 to 22.

(30) FIGS. 3 to 7 show a drive cable 30 which has a cable body 32 composed of a flexible cable core 34 and a coil 36 surrounding cable core 34 in a helical line. Cable core 34 is a monolithic steel wire or a steel wire rope. Coil 36 consists of a steel wire.

(31) Cable body 32, which forms what is referred to as a helix cable, is provided with a plastic coat 38 which consists of a polyamide, in particular of PA11. In the area of coil 36, plastic coat 38 is provided with a flattened portion 40, which consequently defines the circumferential surface of plastic coat 38 and thus of coil 36 and which also follows a helical line.

(32) Furthermore, drive cable 30 has a cable sheath 42 which is composed of two layers, namely an adhesive layer 44 and a cover layer 46. Adhesive layer 44, which is made of a long-chain polyethylene, serves to glue cable sheath 42 to cable body 32. Cover layer 46 forms the circumferential surface of drive cable 30 and is made of a polyamide, in particular of PA6. As shown in FIG. 7, cover layer 46 has ribs 48 which extend in the longitudinal direction of the cable and which may be configured as sacrificial ribs which are broken in during use of the drive cable or during guiding of the drive cable in a cable guide, drive cable 30 thus ideally adapting to the installation conditions.

(33) FIGS. 8 to 12 show a drive cable 50 which largely corresponds to that of FIGS. 3 to 7 but differs from it in that cable body 32 has no plastic coat. Instead, drive cable 50 has a cable sheath 42 which is glued directly to the steel of coil 36 by means of adhesive layer 44 without an additional intermediate layer.

(34) Otherwise, drive cable 50 is identical to that of FIGS. 3 to 7.

(35) FIGS. 13 to 17 show a drive cable 60 which again largely corresponds to that of FIGS. 3 to 7 but differs from it in that it has a cable sheath 42′ composed only a of cover layer 46 which has adhesive properties and which is glued directly to plastic coat 38 of cable body 32 in the area of flattened portion 40 without an additional adhesive layer or adhesion-promoting layer.

(36) Otherwise, drive cable 60 is identical to that of FIGS. 3 to 7.

(37) FIGS. 18 to 22 show a drive cable 70 which largely corresponds to the drive cable of FIGS. 13 to 17 but differs from it according to the embodiment of FIGS. 8 to 12 by having a single-layer cable sheath 42′ comprising only a cover layer 46 which has adhesive properties and which is glued directly to the steel-wire coil 36 of cable body 32 without an additional adhesion-promoting layer and without the plastic coat of cable body 32.

(38) Otherwise, drive cable 70 is identical to the drive cable of FIGS. 13 to 17.

(39) The drive cable illustrated in FIGS. 3 to 7 can be produced in the manner described below using the installation illustrated in FIG. 23.

(40) In a first step, cable body 32, which is composed of cable core 34 and coil 36, is provided with a thin plastic coat made of a PA11 polyamide and is provided on a roll 80. Cable body 32 is unwound from roll 80 and conveyed to a heating station 2, where it is heated for pre-treatment. Then, heated cable body 32 provided with plastic coat 38 is introduced into an extrusion die 84, in which plastic coat 38 is first provided with flattened portion 40 in the area of coil 36 to produce an enlarged surface of contact, and then a plastic tube is applied to cable body 32 by co-extrusion and glued to cable body 32 to form cable sheath 42. The plastic tube is composed of adhesive layer 44 and cover layer 46. Adhesive layer 46 consists of a polyethylene and establishes an adhesive connection between cable sheath 42 and cable body 32. The extrusion process in extrusion die 84 may also take place using support air, causing a cable sheath having a constant outer diameter and outer cross-section across the length of the drive cable to be formed on cable body 32. Then, drive cable 20 consisting of cable body 32 and cable sheath 42 is conveyed to a calibration device 86 which is realized as a vacuum calibration device and in which drive cable 20 is cooled and simultaneously subjected to a vacuum so that cable sheath 42 does not shrink more in the area of the coil gaps of cable body 32 than in the area of coil 36. This calibration of the not yet set plastic layers of cable sheath 42 continues until sufficient solidification is achieved and no further shrinkage of cable sheath 42 is to be expected. The vacuum in the calibration device pulls tube-shaped cable sheath 82 radially outward against a calibration boundary, which predetermines the structure of the circumferential surface of cable sheath 42 and also ensures that the desired shape of cable sheath 42 is maintained. In calibration unit 86, drive cable 20 is additionally moved through a cooling basin 88 filled with water. Cooling basin 88 is typically longer than the section of calibration unit 86 in which drive cable 20 is subjected to the vacuum.

(41) Downstream of the calibration device, drive cable 20 is wound onto a roll 92 by means of a conveying device 90. Thereafter, it can be processed further.

(42) The process described above allows precise tuning and setting of tolerances of the outer diameter and the outer structure of drive cable 20.

REFERENCE SIGNS

(43) 10 vehicle roof 12 roof opening 14 lid element 16A,B drive slide 18A,B guide rail 20 drive cable 22 drive motor 24 drive pinion 30 drive cable 32 cable body 34 cable core 36 coil 38 plastic coat 40 flattened portion 42 cable sheath 44 adhesive layer 46 cover layer 48 ribs 50 drive cable 60 drive cable 70 drive cable 80 roll 82 heating station 84 extrusion die 86 calibration unit 88 cooling basin 90 conveying device 92 roll