ES2230632T3 - ELECTRICALLY OPERATED DEVICE FOR A PROJECTOR. - Google Patents

Abstract

The electrically operated spotlight unit is controlled by an electric motor and can have colour changing, dimming, and blinding facilities. The light may be a platform spot light tat has a holding device (30) that holds the illumination device up high. The preferably annular attaching piece is attached also to the spot light. The annular torsional element (32) has a hinge which may potentially act as a light spreading device (28) which is hingeable relative to the attachment piece (31). The electrical feed cable (39) for the unit is fixed at the part near the attaching element and at the part near the swivel component, but left free in between.

Description

Electrically operated device for a projector.

The invention relates to a device electrically powered, particularly a powered device by electric motor, for example a color changer, valve dimming lights, blinds or similar, for a projector, Especially for a stage projector.

The device serves to influence the light coming from the projector. It presents a clamping device, which Can be connected to the projector for holding the device by means of a fixing element, preferably shaped annular, and having a rotating element, preferably with annular shape, which can rotate around a rotating shaft that extends in a direction of expansion of the potential light, with with respect to the fixing element. The fixing element and / or the rotating element circle the rotating shaft at least partially at a distance.

Devices of the type above mentioned are generally known. The projectors are preferably housed between the two wings of a shaped frame U rotatably around a horizontal axis. He frame itself is rotatably housed around an axis vertical. In this way the projector can be practically aligned over any desired point. It is often desirable to have the device holding device in front of or next to the projector light output. The clamping device is generally housed in a rotating mode, that is to say around a rotating shaft that extends in a direction of expansion of The potential light. If the device is electrically operated it is it is necessary to establish an electrical connection, preferably between the device in the clamping device housed so rotating and stationary projector. Conventionally this electrical connection is made using a power cable freely combined, which allows rotational movements of the clamping device with respect to the projector. Cable power must have a length corresponding to the area of rotation. Due to its length this power cable can be annoying, particularly when the projector is arranged directly on the ground. Then there is a risk of that people, particularly stage workers, they catch on the power cord or that during assembly from the projector the power cord part freely Suspended is damaged.

Another device of the aforementioned type is known for example by US-A-4,729,071.

The object of the present invention is provide an electrically operated device, particularly powered by electric motor, to influence the projector light, particularly a stage projector of the initially mentioned type, in which a cable is arranged power if possible outward, free of interference and space saving.

This object is resolved with a device with the characteristics of claim 1. The improvements are subject to the dependent claims.

The device according to the invention for a projector features a clamping device that can be connected with the projector for securing the device by means of a fixing element, preferably with an annular shape, and which it has a rotating element, preferably with an annular shape, which can rotate around a rotating shaft that extends in a direction of expansion of the potential light, with respect to the fixing element The fixing element and / or the element rotating circle around the rotating shaft at least partially a distance. A power cord for the device can be placed or is fixedly placed in a first cable section with respect to the fixing element and in a second cable section with respect to the rotating element. A third section of cable that extends approximately in the perimeter direction, which is in the extension of the cable between the first cable section and the second cable section, go back at least one cable point, forming a loop of investment almost in the direction of investment, so that with a rotation of the clamping device varies the position of the loop of investment with respect to the first and second section of cable.

The principle of the invention consists in roll back the power cord that extends approximately in the perimeter direction, forming a loop of inversion, so that by varying the relative position of the loop of inversion with respect to the fixed cable points in the element of fixing or on the projector and on the rotating element, you can rotate the rotating element against the fixing element. By Thus, the cable can extend in any turning position in the perimeter direction of forward and reverse. Therefore, to allow a twist, it should not hang especially from the device or projector and cause clogging.

The default investment loop also prevents a risk of compression of the cable, since the inversion loop is moves together with the clamping device according to the movement Rotary of it. Especially it can cause a cable immobilization on the one hand in the stage projector  stationary and, on the other hand, in the clamping device housed rotatably, so that the locked ends they point each time to the same perimeter direction.

In a configuration of the invention, the cable power, which is preferably formed as a flat cable, is arranged between the stationary stage projector and the clamping device housed rotatably, without being accessible or visible from outside. The cable layout is performed within a perimeter channel or channel section in the area of the rotating housing between the stage projector and the clamping device

Preferably the third cable section, which It is located in the extension of the cable between the first and the second section, is inverted or can be reversed by means of a investment element approximately in the investment direction, so that the investment element is mobile along a guide by an outer perimeter of the rotating element and / or the fixing element, so that within a continuous area of twist positions is the third section of low cable tensile stress

Due to the guided investment element it is not a closed channel type guide is necessary, although it is possible. By consequently, the guide can be performed so that the third Mobile cable section is easily accessible, so that the power cable can for example be easily replaced or can be mounted after placing the clamping device in The proyector. Due to the tensile stress under which find the third cable section, it is guaranteed that the third cable section does not form any unwanted loop and therefore remains stuck or stuck in parts of the device. Especially is possible to use all types of cable, so however a cable that can be reversibly curved in the third section of cable.

In a refinement of the device, the clamping device features a transmission element elongated that can be reversibly curved at least in one section for the transmission of a force by traction to a third cable section. The fixing element is connected with a first end of the transmission element. The transmission element is extends approximately in the perimeter direction along the perimeter outside of the rotating element and / or of the fixing element, being invested approximately in the investment direction to through a mobile investment element throughout the guide and being connected to the rotating element at a second end. In this way it can be applied in a particularly easy way tensile tension on the third cable section. The element of transmission and the third cable section can be extended by different areas in the outer perimeter, so that it is impossible an annoying rubbing of the transmission element in the third cable section.

The transmission element contains preferably an elastic tensile element to apply the tensile stress It is particularly favorable when the traction element is arranged slightly apart from the outer perimeter at one end of the transmission element, for guarantee a variation of the free and undisturbed length and, when at the same time, a full operating capacity of the element of traction. Preferably this tensile element is a spring in spiral shape The tensile element, due to its elasticity compensates for length variations, for example dilations plastic, transmission element and power cable. A spiral-shaped spring is of particular advantage, since which can be purchased at economic costs and allows a wide variation of the reversible length with respect to its length in state of relaxation

In a refinement, the rotating element It has a rotating stop, with which the second is connected end of the transmission element. The rotating stop complies with consequently two functions. Preferably the rotating stop is arranged at a certain distance with the outer perimeter of the element fixing, in which the guide for the element of investment. The rotating stop is then in the direction radial more distanced from the rotating shaft than the outer perimeter. An advantage of this configuration is a good accessibility of transmission element and therefore easy assembly with Simultaneous security of the free twisting of the device subjection.

The investment element for the investment of power cable and investment element for investment of the transmission element may be the same component. Without However, it is preferred that the investment element for the investment of the power cable is a first investment element, which the investment element for the investment of the element of transmission is a second investment element and that both investment elements are arranged one behind the other and in a fixed position with respect to each other. By means of the distribution of investment functions over two elements of investment allows for easier handling and adaptation to characteristics, for example dimensions, friction coefficients or flexibility of the parts to be inverted.

An improvement is preferred in which the investment element or at least one of the investment elements it is an inversion roller with a groove to guide the cable of power or transmission element. Power cable or the transmission element can be unwound without sliding through the groove, with sliding or simply by guided sliding in the groove, when the clamping device It makes a rotational movement. In case of waiting for a sliding, for the inversion roller a material, particularly a storage material with which surfaces can be manufactured especially with little friction. A touch reduced prevents on the one hand the wear and, on the other hand, the development of considerable noise. It is preferred that at least one Reversal roller is rotatably housed, preferably on an axis, so that it unwinds in the guide when torsion of the rotating element occurs. For this one unwinding movement correspondingly serves what previously mentioned.

It is favorable if the rotating element is equipped on its outer perimeter with a rolling surface that extends in perimeter direction, side-walled by way slot, which is the guide for the investment element or the investment elements. The tread surface is preferably a smoothed metal surface, particularly polished Alternatively to this configuration is in the rolling surface a cavity that extends in the direction perimeter, by which the investment element is guided sideways. In the alternative cited first the manufacturing is especially simple, since for example the rolling surface is formed by the outer perimeter of a circular plate, on which two plates are coaxially mounted thinner equally circular for the side sandwich of the rolling surface, with a larger outer radius.

The device according to the invention allows mainly the use of power cables with Any cross section. However, a cable is preferred power supply that is formed as a flat cable and that is arranged or it can be arranged so that in the third cable section extends a flat side approximately along the guide, particularly of the rolling surface. In a form of proper realization of the investment element, for example, using a reversing roller, a flat cable arranged or that can be arranged in this way favors the guide during the Execution of its function.

The invention is described below in more detail with the help of the attached drawings as an example. Without However, it is not limited to the exemplary embodiments shown in the drawings The individual figures of the drawings show:

Fig. 1 the essential part of a device clamp rotatably housed in the light output of a projector not shown in more detail, in schematic view from above,

Fig. 2 the construction according to Fig. 1 in section longitudinal line A-A in Fig. 1 and

Fig. 3 the clamping device according to Fig. 1 in a modified turning position with respect to Fig. 1.

Fig. 4 a perspective representation of a clamping device of a second embodiment of the invention,

Fig. 5 another perspective representation of clamping device in partial view and

Fig. 6 a side view of two rollers of inverted together of the clamping device according to Fig. 4 and 5.

A first embodiment of the invention it is now described with the aid of Fig. 1 through Fig. 3.

The clamping device 10 to influence the light coming from a projector not shown is used to hold one or more electrically operated devices, such as color changers, dimmer valves, blinds or similar, which are not represented either.

A basic element of the clamping device 10 it is a ring 11 on which a plate can be mounted, for example assembly that carries the aforementioned devices and with which these devices are rotatable around an axis swivel 20, which in Fig. 1 and Fig. 3 is vertically on the image plane. On the side of ring 11 oriented a circular ring 12 is arranged towards the projector, which has radially on the outer side an E-shaped profile, where a perimeter groove 13 formed in this way serves to house by at least three bearing rollers 15 arranged uniformly distributed over the circumference of the light output of the projector, being rotatably housed, particularly ball or needle bearings. The other perimeter groove 14 serves to house a drive chain 16 or alternatively a drive belt, so that drive chain 16 is coupled with a pinion 17 of an electric motor mounted on the projector, particularly a gradual speed motor or motor reducer. To ensure the drag of the ring 11 and, therefore, of the rotating part of the clamping device 10, by means of the drive chain 16, is connected at least one point with ring 11 or with ring 12 connected to it. This fixation of the chain simultaneously produces a limitation of the angle of turn for the clamping device 10.

The clamping device 10 as well as the plate assembly not shown in Fig. 1 to Fig. 3 have a central passage opening 18 for the light coming from the projector, from so that the clamping device 10 completely surrounds the rotating shaft 20 at a certain distance. Particularly the clamping device 10 limits the light output from the projector according to its circumference due to its disposition before the light output from the projector.

The electrical connection to the rotating element of the electrically operated device is established by a cable Power 19 which is a flat cable. A section of the cable power 19 passes through the inside of a perimeter channel 21 formed by the clamping device 10, where a flat side is oriented to the rotating shaft 20. Always another cable section, particularly one end, it is placed, especially attached, fixedly with respect to the stage projector or with respect to a fixing element connected to a projector and with respect to the rotating element of the clamping device 10. The shaft swivel of the clamping device is marked in figures 1 and 3 with the reference number 20. The rotating shaft is aligned preferably with the optical axis of the stage projector.

Within the perimeter channel 21 is located the power cable 19 forming an inversion loop 24, of way that moves without risk of compression when turning the clamping device 10 within the perimeter channel. The tie of inversion 24 then modifies its position within the channel perimeter 21, always approximately in the middle of the angle of rotation of the clamping device 10.

As can be deduced from Fig. 2, ring 12 arranged, particularly adapted, to the clamping device 10 or to its ring 11, it forms with the ring 11 a radially L-shaped profile on the inner side This L-profile limits the perimeter channel 21, together with a complementary L 26 profile, arranged so fixed with respect to the projector. The profile in L 26 passes through an angle perimeter corresponding to the maximum angle of rotation of the device of clamping 10, for example passing through a perimeter angle of at minus 180 ° to 270 °. Through the complementary L-profiles you are formed the correspondingly long and closed perimeter channel 21 essentially in all directions, to house the cable power supply 19.

In Fig. 2 a piece of a fixing element formed as a front plate 27, which is connected to the projector and that defines as screens the expansion angle of the projector light. The profile in L 26 is fixed on the front plate 27. The front plate 27 may be a projector component, a separate component or be a component Of the device. Preferably on the front plate 27 is the pinion 17 is also rotatably housed and, thus, also assigned to the front plate 27 the assigned drive to pinion 17.

As Figure 2 shows, the L-profiles form a closed channel symmetrically opposite each other essentially on all sides with a cross section rectangular or square The power cord 19 made as Flat cable is secured inside this channel. Also I know creates a space radial enough for loop formation of investment 24 mentioned.

The axial distance of the clamping device 10 housed rotatably from the front plate 27 is guaranteed by the mentioned bearing rollers 15, due to their location in the upper perimeter groove 13 in the figure 2.

Alternatively bearing rollers 15 they may also be assigned to the lower perimeter groove 14 in figure 2. Then the collection of the drive chain 16 is performed inside the upper perimeter groove 13.

It should also be noted that, at the points of tighten 22, 23 of flat cable 19, this is always folded so that the final sections of the flat cable are extend at a 90 ° angle to the flat cable and inside of the plane of the same.

In the described embodiment, it is guaranteed a defined guide of the power cable through a channel closed profiling in cross section. The channel prevents particularly an escape from the outward inversion loop and the annoying effect initially mentioned related to the same.

By means of figures 4 to 6 a then a second embodiment especially Preferred of the invention. All manifested features in relation to the first embodiment they are taken in consideration individually or several for a combination with characteristics of the second embodiment, provided that this combination be reasonable. For example the arrangement of reversing rollers described below can be arranged in a channel closed profiling according to Fig. 2.

In the second embodiment there is a defined guide for a mobile section of a power cable, where the mobile section is well accessible.

The clamping device 30 shown in Fig. 4 can be used to hold a powered device electrically, which can be connected to the projector to influence the light coming from a projector. For this purpose the ring octagonal 48 is fixed at the projector's light output, so which has a light attenuation effect laterally to its around. The octagonal ring 48 is a component of the element of fixing 31 or can be connected with fixing element 31 during assembly of the clamping device 30. In Fig. 4, show eight joints per thread 49 evenly distributed over the octagonal ring 48 towards an annular plate of the element of fixing 31. On the lower side of the clamping device 30, which in the assembled state forms the side of the clamping device 30 away from the projector, the device part is mounted electrically operated not shown. The driven part electrically it can be particularly an attenuation valve of lights that, being powered by electric motor, can be opened or close. The electrically operated element is connected to the rotating ring 32.

The rotating ring surrounds a rotating shaft 20 extending in a direction of expansion of the central light potential 28 at a distance. This one is hosted in a way rotating around the rotating shaft 20 with respect to the element for fixing 31. For this purpose the clamping device 30 It has a rotating bearing with an annular shape not shown, preferably a ball bearing, disposed between the element of fixing 31 and rotating ring 32. For the actuation of a rotary movement can be used for example the arrangement of drive described with the aid of Fig. 1 and Fig. 3.

For the part of the driven device electrically, a power cable made as a flat cable 39 passes from a plug 43 on the outer perimeter of the fixing element 31 along an inversion roller of cable 33, in which the flat cable 39 is inverted approximately in the direction of investment until the part of the electrically operated device. In the representation of the Fig. 4 and Fig. 5, the flat cable 39 ends in a rotating stop 47 in the right half of the image. In case of a device fully mounted can be fixed on this rotating stop 47 for example a contraction device for the flat cable 39. It is also possible to place the flat cable 39 in another way. fixed with respect to the rotating device 32 or with respect to the electrically operated part of the device. In any case, however, the power cable, in this case the flat cable 39, presents a first section of cable 40 in which it is fixedly positioned with respect to the fixing element 31, a second section of cable 41 in which it is fixedly placed with respect to the rotating element 32 and a third cable section 42, which during the rotation movements of the device clamp moves with respect to both the fixing element 31 as well as the rotating ring 32.

The third cable section 42 is in a continuous area of turning positions under tensile tension. Tensile tension is obtained by a transmission element 36 formed by a traction rope 37 and a spiral-shaped spring 38. Conversely, the third cable section 42 also exerts a force of according to the Newtonschen Axiom Actio gleich Reactio traction that produces a tensile tension of the transmission element 36, on the transmission element 36. The transmission element 36 is connected thereto to its first end at the outer perimeter of the fixing element 31. At its second end 45 is connected with a rotating stop 47 which can be seen in Fig. 4 and Fig. 5 in the left half of the image. At this point the spiral-shaped spring 38 is connected to the rotating stop 47 with the end of the traction rope 37. Particularly, using a traction rope 37, which is only extensible to a lesser extent, an effective guide is therefore guaranteed. and yet simple of the third cable section 42. Essential for this is also the rolling surface 35 to which the flat cable 39, the transmission element 36 and the respective reversing roller 33; 34 are guided in the perimeter direction. Unlike the already known embodiment described at the beginning of a device of its kind, an outer guide for the third cable section 42 is missing here. The function of said outer guide is assumed through the forces exerted by the element of transmission 36 and the flat cable 39 reciprocally with each other.

The construction of the inversion rollers 33; 34 and its connection is described by means of Fig. 6. The roller of reversal of the cable 33 has an axial central bore or a recess, in which an axis 53 is arranged. The axis 53 is provided at its ends with an external thread on which it is screwed a nut 52. At the same time one end stands out by a hole in a connection plate 46 towards the side of the plate connection 46 section of the cable reversing roller 33. So similar the tension rope reversing roller 34 is connected to junction plate 46. However the right nut 52 shown covered, is arranged for mounting the roller inversion of cable 33 within a recess 30 formed within of the same. The cable 33 reversing roller has a groove 50 approximately rectangular in a profile to house the cable flat 39. The tension rope reversing roller 34 on the contrary it has a narrow conical groove 51 in the profile to house the traction rope 37. The tread plane for traction rope 37 defined by slot 51 subdivided slot 50 in two approximately equal and symmetrical halves the one with respect to the other, so that guidance is provided correct center by means of traction rope 37 on the surface of rolling 35 (Fig. 5). For this reason the rolling surface 35, slot-shaped sandwich, has only a small groove profile depth, that is, the excess of both walls is sparing laterally to the rolling surface 35 in the radial direction outwards.

By means of the device according to the invention, particularly by the embodiment especially preferred and previously described, reliable guidance of a power cable inside a defined space over a continuous area of rotation positions of the device 10. With reason for the special construction of the clamping device of the device simplifies handling, particularly mounting and maintenance, compared to known devices.

List of references

10

Clamping device

eleven

Ring

12

Ring

13

Perimeter groove

14

Perimeter groove

fifteen

Bearing roller

16

Drive chain

17

Pinion

18

Passage opening

19

Cable feed

twenty

Axis rotary

twenty-one

Channel perimeter

22

Point cable tightening to the projector

2. 3

Point cable tightening to the rotating element

24

Tie investment 25

25

Rotation direction

26

L profile

27

License plate frontal

28

Direction of light expansion potential central

30

Clamping device

31

Fixing element

32

Rotating ring

33

Cable reversing roller

3. 4

Rope reversing roller motor

35

Walled tread surface of slot type

36

Transmission element

37

Traction rope

38

Spiral-shaped spring

39

Cable flat

40

First cable section

41

Second cable section

42

Third cable section

43

Connection plug

44

First end

Four. Five

Second end

46

License plate of connection

47

Stop, top, maximum as a noun, top as an adverb rotary

48

Octagonal ring

49

Union by thread

fifty

Groove

51

Groove

52

Nut

53

Axis

54

Axis

Claims (18)

1. Electrically operated device, particularly an electromotor operated device, for example a color changer, dimmer valve, blind or the like, to influence the light coming from a projector, especially a stage projector, with a clamping device (10, 30) that can be connected to the projector for securing the device by means of a fixing element (31), particularly with an annular shape, and having a rotating element (11, 12, 32), particularly with an annular shape , which can rotate around a rotating shaft (20) that extends in a direction of expansion of the potential light (28), with respect to the fixing element (31), particularly actuated by rotation, where the fixing element (31 ) and / or the rotating element (11, 12, 32) extend at least partially at a distance around a rotating axis (20), characterized by the fact that a power supply cable (19, 39) for the device, which is placed or can be fixedly placed in a first cable section (22, 40) with respect to the fixing element (31) and in a second cable section (23, 41) with respect to the rotating element (11, 12, 32), in a third cable section (42) that extends approximately in the perimeter direction 25, recedes between the first (22, 40) and the second (23, 41) section of cable forming an inversion loop (24) in the inversion direction, so that with a twist of the clamping device (10, 30) the position of the inversion loop varies with respect to the first (22, 40) and the second (23, 41) cable section. 2. Device according to claim 1, characterized in that the power cable (19) is formed as a flat cable and extends in the third cable section with the flat side approximately parallel to the rotating axis (20) of the clamping device (10). Device according to claim 1 or 2, characterized in that the power cable (19) extends inside a perimeter channel (21) formed between the clamping device (10) and the stage projector. Device according to claim 3, characterized in that the clamping device (10) comprises a mounting ring (11) as well as a mounting plate mounted above with a central passage opening (18) for the exit of the light. Device according to one of claims 1 to 4, characterized in that a rotating bearing is formed between the stage projector and the clamping device (10), on the one hand, by a ring (12) arranged in the clamping device (10) and, on the other hand, by at least three bearing rollers (15) arranged in the spotlight projector distributed uniformly over its perimeter and unwinding therein, or vice versa. Device according to claim 5, characterized in that the ring (12) disposed in the clamping device (10) is formed radially on the outer side as an E-shaped profile, where a perimeter groove (13) serves to house at least three bearing rollers (15) and the other perimeter groove (14) to house a drive chain (16) or a drive belt, which is coupled with a pinion (17) or a drive disk of an electric motor, particularly a gradual speed motor or reduction motor, mounted on the stage projector 5. Device according to claim 5 or 6, characterized in that the ring (12) disposed in the clamping device (10) is formed radially on the inner side as an L-shaped profile, which in the assembled state of the clamping device (10) limits the perimeter channel (21) mounted with an L-profile (26) inverted to the stage projector around its light output, to house the power cable (19). Device according to claim 7, characterized in that the L-profile (26) that extends in the spotlight around the light output is a section of profile, which extends by a corresponding perimeter angle at the maximum rotation angle of the clamping device (10), especially at an angle of at least 180 ° to approx. 270 °, so that a correspondingly long and essentially closed perimeter channel (21) is defined to all sides, to house the power cable (19), so that the reversal loop (24) of the power cable (19) ) inside the perimeter channel you can effortlessly follow the turning movement of the clamping device (10). Device according to one of claims 1 to 8, characterized in that the third cable section (42) is inverted or can be inverted by an inversion element (33) forming the inversion loop approximately in the direction of inversion. , and that the reversing element (33) can move along a guide (35) in an outer perimeter of the rotating element (32) and / or of the fixing element (31), so that in a continuous area of The third section of cable (42) under tension by tension is found to be turned. Device according to claim 9, characterized in that the clamping device (30) has an elongated transmission element (36) that can be reversibly curved in at least one section, to transmit a tensile force on the third section of cable (42), that the fixing element (32) is connected to a first end (44) of the transmission element (36) and that the transmission element (36) extends approximately in the perimeter direction, is reversed by a reversing element (34) movable along the guide (35) approximately in the direction of inversion and is connected to the rotating element (32) at a second end (45). Device according to claim 10, characterized in that the transmission element (36) comprises an elastic tensile element (38) to provide the tensile tension. 12. Device according to claim 11, characterized in that the traction element (38) is a spiral-shaped spring. 13. Device according to one of claims 10 to 12, characterized in that the rotating element (32) has a rotating stop (47) with which the second end (45) of the transmission element (36) is connected. 14. Device according to one of claims 10 to 13, characterized in that the investment element (33) according to claim 9 is a first investment element, that the investment element (34) according to claim 10 is a second investment element and that both investment elements (33; 34) are arranged one behind the other in the perimeter direction and in a fixed position with respect to each other. 15. Device according to one of claims 9 to 14, characterized in that the inversion element (33) according to claim 9 or at least one of the inversion elements (33; 34) according to claim 14 is a roller with a slot (50; 51) to guide the power cable (39) or the transmission element (36). 16. Device according to claim 15, characterized in that at least one inverter roller is rotatably housed, preferably on an axis (53, 54), so that it unrolls upon twisting of the rotating element (32 ) in the guide (35). 17. Device according to one of claims 9 to 16, characterized in that the rotating element (32) has on its outer perimeter a rolling surface that extends in the perimeter direction and laterally walled as a groove, which is the guide (35) for the investment element or the investment elements (33; 34). 18. Device according to claim 17, characterized in that the power cable (39) is formed as a flat cable, which is arranged or can be arranged such that a flat side extends in the third cable section (42) approximately along the rolling surface.