Shading device for a transparent area of ​​a motor vehicle

Abstract

A shading device (1) for a transparent area of ​​a motor vehicle, comprising a flexible shading strip (2) which is held on a winding shaft (7) so as to be wound up and unwound, and which is connected at a front end region in the unwinding direction to a dimensionally stable extension profile (3), wherein the light transmission of the shading strip (2) is variable depending on a tensile stress acting in the winding or unwinding direction, wherein a stationary locking device (13) is provided to secure the extension profile (3) in an unwound end position, and wherein a control device is associated with the winding shaft (7) which, depending on the securing of the extension profile (3) in the unwound end position, rotates the winding shaft (7) in order to effect a change in the tensile stress of the shading strip (2), and wherein a drive system is provided.to move the shading strip (2) and the extension profile (3) between a wound-up rest position and the unwound end position, wherein the drive system is operatively connected to the control device, characterized in that the drive system has a cable pull system which is provided for moving the extension profile (3) between the rest position and the end position, and which is operatively connected to the winding shaft (7) in order to effect a rotary movement of the winding shaft (7) for unwinding and winding the shading strip (2), and in that the control device has at least one control element (9) attached to the cable pull system which cooperates with the locking device (13) for securing and / or releasing the extension profile (3) in the end position.

Description

[0001] The invention relates to a shading device for a transparent surface area of ​​a motor vehicle according to the preamble of claim 1.

[0002] Such a shading device is known from DE 10 2019 109 194 A1. The known shading device comprises a flexible shading sheet connected at its end to a dimensionally stable extension profile. The light transmittance of the shading sheet can be varied depending on a tensile stress acting in the winding or unwinding direction. For this purpose, a control device is provided, which is coupled to a drive system that moves the shading sheet and the extension profile between a rest position and an end position.

[0003] Another shading device is known from DE 20 2007 013 762 U1. The known shading device is intended for a side window of a passenger car and has a shading sheet made of an elastic material in which recesses in the form of horizontal slots are provided evenly distributed over its surface. The shading sheet is held on a winding shaft so that it can be wound up and unwound and is connected at its front end region in the unwinding direction to an extension profile, which is acted upon by a drive rod of a drive for the shading device. A coil spring integrated into the winding shaft permanently acts on the shading sheet in the winding direction. The extension profile is assigned a stop which is movable relative to the extension profile in the extension direction and is pretensioned by a compression spring such that it projects upward relative to the extension profile in the extension direction.When the shading sheet is extended by the drive rod engaging the extension profile, the stop strikes the upper edge of the window frame. If the drive force of the drive rod on the extension profile is increased to such an extent that the compression spring between the stop and the extension profile is compressed in the extension direction, an increased tensile force is transferred to the shading sheet, causing the horizontal slits to open. This changes the light transmission of the shading sheet.

[0004] The object of the invention is to provide a shading device of the type mentioned at the outset which enables a reliable change in the light transmittance of the shading sheet, regardless of the spatial environment of the shading sheet.

[0005] This object is achieved by the features of claim 1. The solution according to the invention is suitable for shading transparent surface areas that define a vehicle interior, in particular for a rear window, a side window or a transparent roof area of ​​a passenger car. A motor vehicle is understood to be a vehicle on land, on water or in the air. The solution according to the invention is particularly advantageous for wheeled vehicles for the transport of people. The solution according to the invention fixes the extension profile in the shading position and controls the winding shaft for a change in the tensile stress of the shading sheet and thus for a change in the light transmittance. This means that a change in the light transmittance is independent of the spatial environment of the shading sheet.In particular, unlike the prior art, a fixed stop is not required, against which the extension profile must travel a limited additional distance to change the tension of the shading sheet. Furthermore, the controlled rotation of the winding shaft, due to the lack of travel limitation, allows for greater tension travel for the shading sheet than with the prior art, so that – depending on the design of the shading sheet – higher or lower levels of light transmission can be achieved than with the prior art. The flexible shading sheet is preferably designed to be elastic in the winding and unwinding directions to enable it to return to an unloaded initial position after a corresponding change in the tension.Advantageously, the shading sheet is provided with slits or similarly designed openings - evenly distributed over a surface of the shading sheet - which are widened or remain opaquely contracted depending on the tensile stress.

[0006] According to the invention, a drive system is provided for displacing the shading track and the extension profile between a wound-up rest position and the unwound end position, wherein the drive system is operatively connected to the control device. Preferably, the extension profile is displaceable between the rest position and the end position in vehicle-mounted guides, and drive transmission means of the drive system are assigned to these guides, in particular elongated drive trains in the form of traction means, in the form of compression means, or in the form of combined traction and compression means. Traction means are understood to mean, in particular, cable strands, and traction and compression means are understood to mean, in particular, racks or threaded shafts, which are preferably designed to be flexible.

[0007] According to the invention, the drive system comprises a cable pull system which is provided for displacing the extension profile between the rest position and the end position and which is operatively connected to the winding shaft to effect a rotary movement of the winding shaft for unwinding and winding the shading sheet. The cable pull system can comprise a single, preferably circumferential cable pull or several cables pulls. If the extension profile can be displaced in the region of its opposite ends in guides fixed to the vehicle, each guide is preferably assigned a cable pull which are synchronized with one another for a desired parallel displacement of the extension profile between the rest position and the end position. The synchronization is then part of the drive system.The cable pull system preferably has one or more cable drums, over which at least one corresponding cable strand can be wound or unwound in order to achieve a desired displacement of the respective cable strand along the vehicle-fixed guides or along the movement path of the shading track. The cable pull system preferably has two cable drums arranged coaxially to the winding shaft and connected to the winding shaft in a rotationally fixed manner, onto each of which a cable strand can be wound in the opposite direction of rotation to the other cable strand. This makes it possible to drive the winding shaft in both directions of rotation using the cable pull system, without the need for an additional return spring integrated into the winding shaft to drive the winding shaft in the winding direction.The rope drums can be arranged on a single, common end region of the winding shaft or on opposite end regions of the winding shaft and connected to the winding shaft in a torque-transmitting manner.

[0008] According to the invention, the control device comprises at least one control element attached to the cable pull system, which interacts with the locking device to secure and / or release the extension profile in the end position. The control element therefore serves to activate or deactivate the locking device by directly or indirectly transmitting the position of the extension profile to the locking device upon reaching the end position.

[0009] In one embodiment of the invention, the drive system comprises an electric drive unit for driving the cable pull system. The electric drive unit preferably comprises a single electric drive motor, which synchronously drives several cable drums of the cable pull system by means of a gear.

[0010] In a further embodiment of the invention, the extension profile has at least one guide member designed to be driven along by the control element in the unwinding direction of the shading sheet. The extension profile is preferably provided with a guide member on each of its opposite end regions, which guide members are guided in opposite guides fixed to the vehicle. The number of control elements preferably corresponds to the number of guide members, so that if there are two guide members, two control elements are attached to correspondingly opposite cable strands of the cable pull system. The guide member is preferably arranged floatingly relative to the cable pull system, so that the guide member is only driven along with the cable pull system when the control element attached to the cable pull system contacts the guide member and drives it along in the unwinding direction of the shading sheet.

[0011] In a further embodiment of the invention, the locking device is designed to secure or release the guide member in the end position of the extension profile. The locking device is preferably mechanical and ensures a positive locking of the guide member. Alternatively, the locking device can be magnetic, either by means of an electromagnetic function or by means of a permanent magnet function.

[0012] In a further embodiment of the invention, the locking device has a securing element that is movably mounted between a locked position and a released position, which positively blocks the guide member of the extension profile in the locked position and releases the guide member in the released position. A pivoting latching hook is preferably provided as the securing element. Alternatively, a linearly movable latching element can be provided. If a latching hook or a differently designed latching element is provided, the guide member has at least one correspondingly complementary latching profile to effect the positive locking. It is also possible for the latching element to be designed such that it positively engages behind the guide member in the latched position, so that the guide member requires no additional latching profile.Rather, an end region of the guide member simply serves to be engaged behind by the locking element.

[0013] In a further embodiment of the invention, a switching device is provided that is operatively connected to the securing element to move the securing element between the release position and the blocking position. The switching device ensures that a corresponding release position or blocking position of the securing element is reliably maintained.

[0014] In a further embodiment of the invention, the switching device comprises an activation arrangement that projects into a movement path of the control element in such a way that the activation arrangement actuates the switching device depending on contact with the control element. The activation arrangement is preferably designed mechanically, so that mechanical contact with the control element results in a desired switching function for transferring the securing element into the release position or the blocking position.

[0015] Further advantages and features of the invention emerge from the claims. A preferred embodiment of the invention is described below and illustrated with reference to the drawings. Fig. 1 shows a perspective view of the embodiment of the shading device according to the invention, Fig. 2 schematically shows a cable pull system of the shading device according to Fig. 1, Fig. 3 in perspective view the shading device according to Fig. 1 omitting lateral vehicle-mounted guides in a first position of the cable pull system, Fig. 4 the shading device according to Fig. 3 in another position of the cable pull system, Fig. 5 the shading device according to the Fig. 3 and Fig. 4 in another position of the cable pull system, Fig. 6 shows an enlarged view of section VI of the shading device according to Fig. 3, Fig. 7 shows an enlarged view of section VII of the shading device according to Fig. 3, Fig. 8 shows an enlarged view of section VIII of the shading device according to Fig. 3, Fig. 9 shows an enlarged view of a section IX of the shading device according to Fig. 4, Fig. 10 shows an enlarged view of a section X of the shading device according to Fig. 4, Fig. 11 shows an enlarged section XI of the shading device according to Fig. 4, Fig. 12 shows an enlarged view of section XII of the shading device according to Fig. 5, Fig. 13 shows an enlarged view of section XIII of the shading device according to Fig. 5, Fig. 14 shows an enlarged view of section XIV of the shading device according to Fig. 5, Fig. 15 in opposite Fig. 9 further enlarged view of a section of the shading device according to the Fig. 1 and 3 to 5, Fig. 16 in an exploded view a part of the shading device according to the Fig. 1 to 15 at the level of a locking device, Fig. 17 in an enlarged perspective exploded view a switching device for the locking device according to Fig. 16, Fig. 18a and Fig. 18b in an enlarged view in a release position and a securing position a securing element for a guide member of an extension profile of the shading device according to the Fig. 1 to 17, Fig. 19a and Fig. 19b in different perspective views a part of the shading device according to the Fig. 1 to 18b in a first functional position, Fig. 20a and Fig. 20b the representation according to Fig. 19a and Fig. 19b in another functional position, Fig. 21a and Fig. 21b the representations analogous Fig. 20a and Fig. 20b in another functional position, Fig. 22a and Fig. 22b the representations according to Fig. 21a and Fig. 21b in another functional position, Fig. 23a and Fig. 23b the representations according to Fig. 22a and Fig. 22b in another functional position, Fig. 24a and Fig. 24b the representations according to Fig. 23a and Fig. 23b in another functional position, Fig. 25a and Fig. 25b the representations according to Fig. 24a and Fig. 24b in another functional position, Fig. 26a and Fig. 26b the representations according to Fig. 25a and Fig. 25b in another functional position and Fig. 27a and Fig. 27b the representations according to Fig. 26a and Fig. 26b in another functional position.

[0016] A passenger car (not shown in detail) has a sloping rear window in its interior, which is arranged by means of a shading device 1 according to the Fig. 1 to 27b. The shading device 1 is arranged in the vehicle interior below the rear window of the passenger car. The shading device 1 has a flexible shading sheet 2, which is held on a winding shaft 7 so as to be wound up and unwound. The shading sheet 2 is made of a textile material and is designed to be elastically flexible in the longitudinal direction, ie in the winding and unwinding direction. The shading sheet 2 has a plurality of passages S evenly distributed over its surface, which can be Fig. 1 and Fig. 4 are only shown in detail for reasons of clarity. The passages S are largely rectangular openings in the textile material and each extend transversely to the winding and unwinding direction of the shading sheet 2. The shading sheet 2 is designed in the present case as a woven fabric made of interwoven warp and weft threads. The passages S are woven openings that arise between the woven warp and weft threads through a specific type of weave. The type of weave that creates the passages S is a mock leno weave. The weft threads each have a silicone core that is covered with a polyester thread. The weft threads are therefore elastic. With a corresponding tensile stress, the passages S, which are the spaces between the woven warp and weft threads, open and therefore form an integral part of the woven fabric.When tensile stress is applied, these spaces open and when released, they close again. The warp threads each consist of a continuous polyester yarn. A high level of elasticity is achieved exclusively in the weft thread direction, i.e. in the longitudinal direction of the shading sheet 2. Depending on the design, the woven fabric can be treated with certain finishes in order to achieve the required fire protection properties and dirt / oil repellency. When the tensile force in the longitudinal direction is high, the openings S open. When the tensile force is reduced, the openings S close. The textile material is at least largely opaque, so that when the openings S are closed, the shading sheet 2 has at most a low level of light permeability. When the tensile force in the longitudinal direction is high, the openings S inevitably open elastically, thereby increasing the light permeability of the shading sheet 2.

[0017] The shading sheet 2 is held on the winding shaft 7 at its rear end region in the winding direction. At its front end region in the unwinding direction, the shading sheet 2 is connected across its entire width to a dimensionally stable extension profile 3.

[0018] The winding shaft 7 is rotatably mounted in a cassette housing 4, which, in its fully assembled state, is aligned in the transverse direction of the vehicle below the rear window and fastened to the vehicle side. The pull-out profile 3 is provided at its opposite ends - viewed in the transverse direction - with a guide member 14, each of which is slidably guided in a guide rail arrangement 6 fixed to the vehicle. The two opposing guide rail assemblies 6 are fastened, in their fully assembled state, to C-pillars of a vehicle body of the passenger car and each at least partially form a panel on the vehicle interior side of the respective C-pillar. Each guide rail arrangement 6 has a guide slot (not designated in more detail) facing a center of the vehicle interior, through which the pull-out profile 3 with the respective guide member 14 projects.The pull-out profile 3 can be displaced in parallel between a position in the opposite guide rail arrangements 6 by means of its two guide members 14. Fig. 1, in which the shading web 2 is unwound from the winding shaft 7, and one in Fig. 3 shown rest position, in which the shading strip 2 is wound onto the winding shaft 7 and the pull-out profile 3 rests on the cassette housing 4.

[0019] For winding and unwinding the shading track 2 and for transferring the extension profile 3 from the rest position to the extended end position and back, a drive system is provided which has a drive unit 5 described in more detail below and a cable pull system which is also described in more detail below.

[0020] The cable pull system has two conically shaped winding drums 12, 13, which are arranged coaxially to a rotational axis of the winding shaft 7 and are connected to the winding shaft 7 at opposite ends in a rotationally fixed manner ( Fig. 2). The conicity of the two winding drums 12, 13 is provided to compensate for different winding layer diameters depending on the winding or unwinding state of the shading sheet 2.

[0021] The cable pull system has three cables 8a, 8b, 8c, with one cable end of the Fig. 2 left cable pull 8a on the in Fig. 2 left winding drum 12 and one rope end of the cable pull 8b on the Fig. 2 right winding drum 13. The ropes of the two cable pulleys 8a and 8b are wound and unwound on the two winding drums 12, 13 in opposite directions of rotation. In addition, a Fig. 2 cable pull 8c shown on the right is provided.

[0022] The cable 8a extends along the Fig. 1 left guide rail arrangement 6, whereas the cable pull 8c is along the Fig. 1 right guide rail arrangement 6. Both cable pulleys 8a and 8c are deflected in an upper end region of the respective guide rail arrangement 6 via a deflection pulley (not further designated), so that the two cable pulleys 8a and 8c are each laid with both cable strands along the respective guide rail arrangement 6.

[0023] The two cable pulleys 8a and 8c are driven synchronously by an electric drive unit 11, which synchronously drives two cable drums 10 of the two cable pulleys 8a and 8c. As can be seen from the Fig. 1 and Fig. 2, the two cable drums 10 and the electric drive unit 11 with a corresponding electric drive motor and an associated gear unit, which acts synchronously on the cable drums 10, are accommodated in a housing of the drive unit 5, which is fastened centrally to the cassette housing 4 fixed to the vehicle.

[0024] The cable 8a and the one between the Fig. 2 The cable pulley 8b laid between the left cable drum 10 and the right winding drum 13 serve together to drive the winding shaft 7 in both directions of rotation, ie both in the unwinding direction and in the winding direction. For this purpose, both the cable pulley 8a and the cable pulley 8b engage the Fig. 2 left cable drum 10 of the cable pull system. Depending on the direction of rotation of the cable drum 10, the winding shaft 7 is driven in the winding direction or in the unwinding direction via the rotationally fixed connection with the two opposite winding drums 12 and 13.

[0025] Since the cable pull system also moves the extension profile 3 between its rest position and its end position, the shading device 1 requires Fig. 1 to 27b no return spring in the area of ​​the winding shaft 7.

[0026] In order to move the pull-out profile 3 with its opposite guide members 14, control elements 9 are assigned to the two cable pulls 8a and 8c (see in particular Fig. 2 to 5), which are carried along with the respective cable strand when the cable pulls 8a and 8c move due to their fixed connection to the respective cable pull 8a and 8c. The control elements 9 are slidably mounted in the guide rail assemblies 6. Each control element 9 is designed such that it remains permanently behind the respective guide link 14 of the extension profile 3 in the corresponding guide rail assembly 6. The guide links 14 of the extension profile 3 are not coupled to the cable pull system, but are carried along and supported exclusively by the control elements 9. Both the guide links 14 and the control elements 9 are assigned guide grooves (not shown in detail) within the respective guide rail assembly 6.

[0027] The extension profile 3 is secured in its end position corresponding to a shading position, in which the shading sheet 2 is pulled upwards and thus unwound, by a locking device 13 at an upper end region of the left and right guide rail arrangements 6. The drawings only show the locking device 13 assigned to the left guide rail arrangement 6. The opposite locking device for the right guide rail arrangement 6 is functionally identical. The structure and function of the left locking device 13 are described below. The description applies equally to the opposite locking device.

[0028] The shading device 1 also has a control device by means of which the shading sheet 2 can be rotated back in the winding direction by the winding shaft 7 after the extension profile 3 has reached its extended end position and after the extension profile 3 has been locked in the locking devices 13 fixed to the vehicle. As a result, the shading sheet 2 is inevitably subjected to increased tensile stress in the winding and unwinding direction, i.e. in the longitudinal direction, due to the locking of its front end region in the extension direction. This controls the degree of light transmission of the shading sheet 2, since with an increase in the tensile stress, the passages S in the shading sheet 2 open and close again when the tensile stress is reduced again. The degree of light transmission can be continuously adjusted by correspondingly rotating the winding shaft 7.

[0029] The control device uses the control elements 9 fixed on the cables 8a and 8c. As can be seen from the Fig. 15 ff., each control element 9 has a control pin 15 which projects outwards in the transverse direction and is fixedly arranged on the control element 9 and which interacts with a mechanical switching device at the upper end region of the guide rail arrangement 6, which in turn moves a latching hook 33 of the locking device 13 between a latching position which positively secures the guide member 14 and a release position which releases the guide member 14 for a sliding movement within the guide rail arrangement 6. Corresponding functional components of the locking device 13 and the control device with the switching device are described below with reference to Fig. 15 to 27b are described in detail.

[0030] The switching device has a switching plunger 17, which is guided in a linear guide 19 on the guide rail arrangement for limited displacement. The switching plunger 17 is also pivotally mounted in the guide 19 about a pivot axis extending in the transverse direction. Fig. 15 right leg of the slotted guide 19 is provided with centering bevels 16 on a rear side facing the cassette housing 4 and is otherwise designed to be open in order to prevent the control pin 15 from inserting into the Fig. 15 right-hand part of the guide rail and into a receiving aperture 18 of the switching plunger 17. The receiving aperture 18 forms a stop for the control pin 15, so that upon an upward movement of the control element 9 along the guide rail arrangement, the control pin 15 plunges into the receiving aperture 18 in the area of ​​the centering bevels 16 serving as starting bevels, and thus inevitably carries the switching plunger 17 with it during a further sliding movement of the control element 9. The centering bevels 16 serve to ensure a secure run-in of the control pin 15 into the receiving aperture 18.

[0031] The switching plunger 17 acts on a switching wheel 21, which is mounted on a bearing block 27 of the guide rail arrangement 6 for rotation about a transversely extending axis of rotation. The switching wheel 21 has a total of four switching teeth, viewed in the circumferential direction, into which a transverse bolt of the switching plunger 17, arranged opposite the receiving mouth 18, can engage in order to rotate the switching wheel 21. Four switching recesses 23 are assigned to the switching teeth on an outer end face of the switching wheel 21, which are evenly distributed around the axis of rotation. The switching recesses 23 form cup-like depressions that interact with a non-visible locking knob on a stationary support arm 22 depending on the switching position of the switching wheel 21. The locking knob is positioned on an inner side flank area of ​​the support arm 22 facing the pull-out profile 3 and interacts in a form-fitting manner with one of the switching recesses 23.The locking knob is preferably designed in the shape of a spherical segment, and each of the locking recesses 23 is designed as a complementary spherical depression. The support arm 22 is fixedly arranged on the guide rail arrangement 6 and, in the region of its free end and thus in the region of the locking knob, has a slight elastic mobility in the transverse direction and thus parallel to the rotational axis of the switching wheel 21, in order to easily enable the locking knob to be engaged and disengaged relative to the respective switching recess 23.

[0032] As shown by the Fig. 16 and Fig. As can be seen in Figure 17, the switching wheel 21 is held in a rotationally fixed manner on a bearing shaft 32, which is connected to a switching cam 24, which is held axially relative to the bearing shaft 32 via a bearing disk 25 and a locking screw 31. A leg spring 26 is also arranged between the switching cam 24 and the switching wheel 21.

[0033] The switching cam 24 is arranged to be rotatable to a limited extent relative to the bearing shaft 32 and relative to the switching wheel 21, in this case by an angle of approximately 15°, in order to prevent jamming with a locking hook 33, described in more detail below, during locking. The leg spring 26 forces the switching cam 24 to protrude into the locking position with the locking hook 33 during locking.

[0034] The switching cam 24 has two cam legs projecting towards opposite sides, which project radially to the axis of rotation of the switching cam 24 and the switching wheel 21.

[0035] The switching cam 24 is operatively connected to the locking hook 33. The locking hook 33 is pivotally mounted on a bearing block 28 of the guide rail assembly 6 by means of a bearing pin 29, parallel to the rotational axis of the switching wheel 21. The locking hook 33 has a hook portion that projects substantially radially to its pivot axis. In addition, a control arm is integrally formed on the locking hook 33. The switching cam 24 and the locking hook 33 are permanently in contact with one another. The switching cam 24 either presses the hook portion of the locking hook into a locking receptacle 34 on an underside of the guide member 14, or the switching cam 24 interacts with the control arm to control the hook portion out of the locking receptacle 34.

[0036] The functionality of the described functional components is as follows: When the pull-out profile 3 is in its rest position on the cassette housing 4, according to the Fig. 3 and Fig. 7, Fig. 8 also holds the respective control element 9 within the guide rail arrangement 6 in its lower end position. In this end position, it is positioned directly behind the respective guide link 14 of the extension profile 3. When the cable pull system now drives the control elements 9 upwards in the longitudinal direction along the guide rail arrangements 6, the control elements 6 inevitably carry the guide links 14 with them, causing the extension profile 3 to be displaced parallel between the two guide rail arrangements 6 toward its extended end position.

[0037] As soon as the control elements 9 have been moved upwards so far that the guide members 14 are located in the area of ​​the locking devices 13, the control pin 15 of the respective control element 9 engages the receiving mouth 18 of the switching plunger 17 and, with further movement of the cable pull system, pushes the switching plunger 17 upwards. In doing so, the switching plunger 17 inevitably pushes the switching wheel 21 backwards in the direction of rotation via engagement with a corresponding switching tooth (according to Fig.15). The locking knob of the support arm 22 is thereby inevitably released from one switching recess 23 and engages again in an adjacent locking recess 23. Prior to this, the switching cam 24 is also inevitably rotated with the rotation of the switching wheel 21, whereby the switching cam 24 transfers the locking hook 23 from a release position to a locked position by the switching cam 24 pressing the hook portion of the locking hook 33 into the locking receptacle 34 of the guide member 14. A return spring 20 is assigned to the switching plunger 17, which retracts the switching plunger 17 back to its original position as soon as the control element 9 moves back again, whereby the control pin 15 is released from the receiving mouth 18.The switching wheel 21 remains in the set position due to the locking of the locking knob with the corresponding switching recess 23, so that the locking hook 33 blocks the guide member 14 in a form-fitting manner, even if the control element 9 moves away from the guide member 14 again.

[0038] The control element 9 is removed from the guide member 14 by reversing the direction of rotation of the cable pull system accordingly. This inevitably also applies torque to the winding shaft 7 in the opposite direction of rotation, i.e., it is rotated in the winding direction. Due to the locking of the extension profile 3 in the locking devices 13, this creates an increased tensile force on the shading sheet, so that the openings S widen and the light transmittance of the shading sheet 2 increases. By reversing the direction of rotation of the cable pull system again, the tensile force on the shading sheet 2 can be reduced again, causing the openings S to close again and the light transmittance to be reduced again accordingly.

[0039] To return the extension profile 3 from its extended end position, the control element 9 is moved upwards again in the guide rail arrangement 6 until the control pin 15 of the control element 9 actuates the switching plunger 17 again and rotates the switching wheel into the next detent position. In doing so, the switching cam 24 also inevitably rotates and acts on the actuating arm of the locking hook 33, whereby the hook section of the locking hook 33 is automatically disengaged from the locking receptacle 34 of the guide member. The locking knob of the support arm 22, which is again engaged in the corresponding adjacent locking recess 23, secures the actuated position of the locking hook 33 by ensuring that the switching cam 24 remains in contact with the actuating arm of the locking hook 33.

[0040] By reversing the direction of rotation of the cable pull system accordingly, the shading sheet 2 is inevitably wound onto the winding shaft 7. At the same time, the shading sheet 2 pulls the extension profile 3 downwards. The guide links 14 of the extension profile 3 are supported by the control elements 9, thus preventing the extension profile 3 and its guide links 14 from becoming jammed in the guide rail arrangements 6. The extension profile 3 is now moved back to its rest position, in which the shading sheet 2 is also completely wound onto the winding shaft 7.

[0041] The locking hook 33 forms a securing element within the meaning of the invention. The switching plunger 17, in conjunction with the receiving mouth 18, the guide rail 19, and the return spring 20, forms the activation arrangement within the meaning of the invention.

Claims

[1] Shading device (1) for a transparent surface area of ​​a motor vehicle, comprising a flexible shading sheet (2) which is held on a winding shaft (7) so as to be wound up and unwound and is connected to a dimensionally stable pull-out profile (3) at a front end region in the unwinding direction, wherein a light transmittance of the shading sheet (2) is variable depending on a tensile stress acting in the winding or unwinding direction, wherein a stationary locking device (13) is provided for securing the pull-out profile (3) in an unwound end position, and wherein the winding shaft (7) is assigned a control device which, depending on the securing of the pull-out profile (3) in the unwound end position, sets the winding shaft (7) in rotation in order to effect a change in the tensile stress of the shading sheet (2), and wherein a drive system is provided,to move the shading track (2) and the extension profile (3) between a wound-up rest position and the unwound end position, wherein the drive system is in operative connection with the control device, , characterized by that the drive system has a cable pull system which is provided for displacing the pull-out profile (3) between the rest position and the end position and which is operatively connected to the winding shaft (7) in order to bring about a rotary movement of the winding shaft (7) for unwinding and winding up the shading sheet (2), and that the control device has at least one control element (9) attached to the cable pull system which cooperates with the locking device (13) for securing and / or releasing the pull-out profile (3) in the end position. [2] Shading device (1) according to claim 1, characterized by that the drive system has an electric drive unit (11) for driving the cable pull system. [3] Shading device (1) according to claim 1 or 2, characterized by that the pull-out profile (3) has at least one guide member (14) which is designed to carry the pull-out profile (3) along by the control element (9) in the pull-out direction of the shading web (2). [4] Shading device (1) according to claim 3, characterized by that the locking device (13) is designed to secure or release the guide member (14) in the end position of the pull-out profile (3). [5] Shading device (1) according to claim 4, characterized by that the locking device (13) has a securing element (latching hook 33) which is movably mounted between a locking position and a release position and which positively blocks the guide member (14) of the pull-out profile (3) in the locking position and releases the guide member (14) in the release position. [6] Shading device (1) according to claim 5, characterized bythat a switching device is provided which is operatively connected to the securing element (33) in order to displace the securing element (33) between the release position and the blocking position. [7] Shading device (1) according to claim 6, characterized by that the switching device has an activation arrangement which projects into a movement path of the control element (9) in such a way that the activation arrangement actuates the switching device depending on contact with the control element (9).

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