EP0377844B1 - Raising device for a blind - Google Patents

Abstract

The raising device for a blind comprises two holding parts to be fitted fixed in position, of which the first holding part holds the blind and the second holding part is arranged at a distance from the first holding part. Furthermore, a winding spindle having an outer thread is provided which is mounted rotatably in a bearing which contains an inner thread. The outer thread of the winding spindle is in engagement with the inner thread of the bearing. The device possesses two raising cords, each of which is fastened to a guide element fixedly connected to the blind, completely loops around the winding spindle at least once and is guided with a second section to the second holding part and back to the guide element with deflection. <IMAGE>

Description

The invention relates to an elevator device of a curtain, in particular a roller blind or a folding or slatted blind, with two stationary holding parts, of which the first holding part holds the curtain and the second holding part is arranged at a distance from the first holding part, the curtain between the two Holding parts is movable back and forth, with an externally threaded winding spindle, which is rotatably mounted in at least one bearing containing an internal thread, the external thread of the winding spindle being in engagement with the internal thread of the bearing, and with at least two elevator ropes, each of which is attached to one fixed to the curtain fixed guide element and with a first section directly to the winding spindle and with a second section to the second holding part and deflected from there parallel to the first section also to the winding spindle and engages in their threads.

Elevator devices of this type are known and are generally used for folding or louvre blinds. In general, the first holding part holding the curtain is designed as a head strip and the guide element is designed as a lower strip attached to the lower edge of the curtain. The winding spindle is rotated manually or electrically, the elevator ropes not only being wound around the winding spindle with their two ends in opposite directions, but also knotted on the winding spindle. This arrangement throws up however, problems arise in the installation and operation of the known elevator device. Because when attaching the curtain and the associated elevator device, the fastening of the guide element or the lower bar to the elevator ropes and the winding of the elevator ropes around and their knotting on the winding spindle must be precisely coordinated with one another, so that the guide element or the lower bar is arranged horizontally and can be moved back and forth over the entire distance between the first holding part or the header and the second holding part with the aid of the elevator cables. However, this adjustment requires a lot of skill and time and is therefore very expensive. Another problem arises in the operation of the known elevator device, specifically when the guide element or the lower bar is prevented from moving freely, for example by holding on or due to an unforeseen obstacle. Then there is a risk that at least one of the elevator ropes will break.

It is therefore an object of the invention to further develop the known elevator device of a curtain of the type mentioned in such a way that there is no need for complex adjustment of the guide element and the elevator ropes during assembly and that there is no longer any danger of the elevator ropes tearing during operation, particularly when the guide element is on is prevented from moving freely.

This object is achieved in that the first section of each elevator rope on the winding spindle, completely wrapping it around at least once, merges in one piece into the second section. Ie Each elevator rope is no longer fastened to the winding spindle with its two free ends after being wound up on the winding spindle, but is only looped around the winding spindle along a number of threads, whereupon it leaves the winding spindle again. Thus, the elevator ropes are no longer tied to the winding spindle, but are only in contact with it, so that the elevator ropes can be moved along the threads relative to the winding spindle. This results in a so-called “slip clutch effect”, by means of which the known problems during the adjustment of the guide element and the elevator ropes and during the operation of the elevator device are avoided in an advantageous manner. In particular, the risk of the elevator ropes tearing is prevented during operation if the guide element is prevented from moving freely, since the winding shaft then simply rotates relative to the wound-up part of the elevator ropes. Also due to the "slipping clutch effect", the guide element can be returned to its horizontal position if it should hang down to one side or the other.

Preferably, between the first holding part and the guide element, both sections of each elevator rope run directly next to one another and are guided together by a guide sleeve in the first holding part. This results in a particularly simple and space-saving arrangement of the elevator ropes.

In a further embodiment, the two free ends of each elevator rope are attached to the guide element. This is expedient since, on the one hand, the guide element is to be attached to the elevator ropes and, on the other hand, there is no need to attach the elevator ropes to the winding spindle because of the looping according to the invention.

In a further preferred embodiment, the elevator ropes are under tension in order to ensure reliable guidance of the guide element and in particular secure winding of the elevator ropes around the winding spindle.

In an advantageous further development of this embodiment, at least one end of each elevator rope is connected to one end of a tension spring which is attached to the guide element with its other end. This results in a particularly compact arrangement for the clamping device.

In an additional development, the guide element is designed as a hollow bar, the two free ends of each elevator rope are guided through bores formed in the wall of the guide element and deflected within the guide element, and the tension spring is arranged inside the guide element. Thus, the space within the guide element designed as a hollow rod is used in a space-saving manner, whereby the tensioning device is covered by the guide element and does not disturb the visual impression of the curtain.

In a further preferred embodiment, the guide element is slidably supported on a guide device, which ensures better guidance of the guide element during its upward and downward movement by the elevator ropes.

In an advantageous development of this embodiment, at least one guide rope is stretched between the two holding parts and bores are provided in the guide element through which the guide rope runs. This results in a particularly space-saving and simple design of the guide device.

In a further embodiment of the invention, the guide sleeve for each elevator rope is arranged adjacent to the winding spindle and at a right angle to its axis and is directed towards the winding spindle. Each elevator rope is safely guided through the guide sleeve and deflected to the winding spindle in such a way that a perfect winding results.

In a further development of this embodiment, the axis of the guide sleeve is arranged essentially radially to the winding spindle, so that the elevator ropes are deflected by the same angle on both sides.

Furthermore, a drive device with an electric motor working in both directions of rotation is proposed for driving the winding spindle of the elevator device according to the invention, with a shutdown unit connected to the supply lines leading to the electric motor for switching off the electric motor in an upper and a lower position of the elevator device to be moved curtain is provided. The switch-off unit switches off the electric motor in good time so that the curtain cannot be moved beyond an upper or a lower position, which could otherwise damage the curtain.

The shutdown unit preferably has a threaded spindle, which is rotatably mounted at least in one bearing and is mechanically coupled to the winding shaft. Two threaded bushings are screwed onto the threaded spindle, on each of which a switch cam is detachably fastened. Furthermore, a guide part is provided with which the switching cams are in engagement which can be displaced parallel to the threaded spindle, and two switches are arranged adjacent to the threaded spindle such that a switching cam can be brought into engagement with an actuating element of a switch for actuating the switching contact. The switching cams are arranged between the actuating elements, the distance between them being greater than the distance between the switching cams. The two switches are used to switch off the electric motor when the curtain reaches the upper or lower position, whereby the electric motor drives not only the elevator device but also the threaded spindle on which the switch cams are seated and can be moved back and forth depending on the direction of rotation are. Since the distance between the switching cams is smaller than the distance between the actuating elements of the switches, only one actuating element of a switch can ever be triggered by the associated switching cam. So that the threaded spindle opposite the switching cams can be rotated and the switching cams are not rotated themselves, the guide part is provided, with which the switching cams are in engagement that can be displaced parallel to the threaded spindle. It is particularly advantageous on the switch-off unit that the switching cams are detachably fastened on the threaded bushings seated on the threaded spindle. This releasable attachment allows a particularly simple adjustment of the switching cams on the threaded spindle in their position both with respect to one another and with respect to the actuating elements of the switches.

Each switching cam preferably has two clamping jaws connected by a clamping screw, between which the threaded bushing is held. In this way, the releasable fastening of the switching cams on the threaded spindle is realized in a particularly simple manner. For the adjustment of the switching cams only the clamping screw needs to be loosened a little so that the threaded bushing between the clamping jaws can be rotated and thus the position of the switching cams on the threaded spindle can be changed in the axial direction. Then the clamping screw is tightened again, whereby the threaded bushing is firmly held between the clamping jaws again.

In a development of this invention, the guide part is designed as a rail with a flat surface running parallel to the threaded spindle, with which a side surface correspondingly formed on each switching cam is in flat engagement. Alternatively, with the flat surface at least two radially to the threaded spindle and in one Support feet arranged at a distance from one another are engaged on the switching cams. Such designs of the guide part are particularly simple in their construction. In particular, one of the side surfaces of the holding part or a supporting or upper box to be provided for the elevator device can form the flat surface serving as the guide part.

Fig. 1

einen Seitenabschnitt einer Faltjalousie und der dazugehörigen Aufzugsvorrichtung in teils geschnittener, teils gebrochener Seitenansicht;

Fig. 2

die Aufzugsvorrichtung und den Oberkantenbereich der Faltjalousie im Querschnitt;

Fig. 3

eine Abschalteinheit einer zur Aufzugsvorrichtung zugehörigen Antriebsvorrichtung; und

Fig. 4

einen Querschnitt durch die Abschalteinheit.

The invention is explained below with reference to the embodiment shown in the drawings. Show it:

Fig. 1

a side portion of a folding blind and the associated elevator device in a partly cut, partly broken side view;

Fig. 2

the elevator device and the upper edge region of the folding blind in cross section;

Fig. 3

a switch-off unit of a drive device associated with the elevator device; and

Fig. 4

a cross section through the shutdown unit.

As shown in FIGS. 1 and 2, the curtain 2 of a folding blind is fastened to a holding strip 4 which is attached to the underside of an upper box 6. The top box is used to attach the folding blind to a window or wall and contains an elevator device. This has a winding spindle 10 with an external thread 12. The winding spindle 10 is mounted in a bearing 16 containing an internal thread, the external thread 12 of the winding spindle 10 being in engagement with the internal thread of the bearing 16. A winding shaft is coupled in a rotationally fixed manner to the winding spindle 10 14, which is driven by an electric motor, not shown. As shown in FIG. 2, the winding shaft 14 is a square shaft and extends through a corresponding square inner bore of the winding spindle 10. Since the winding spindle 10 is a screw shaft and the bearing 16 is a fixed nut with which the Winding spindle 10 is in screw engagement, the winding spindle 10 moves back and forth in the axial direction when rotated in the bearing 16. In contrast, because of the fixed connection to the drive shaft of the electric motor, the winding shaft 14 cannot be moved axially back and forth, but is fixed in place, but rotatably. Therefore, the square winding shaft 14 is only loosely inserted into the square bore of the winding spindle 10, so that the winding spindle 10 can also be pushed back and forth with respect to the winding shaft 14 due to the screw engagement with the bearing 16.

An elevator rope 20 is wrapped twice around the winding spindle 10, whereby it is guided along the threads of the external thread 12. The elevator rope 20 is led out in two parallel sections 20 ', 20' through a guide sleeve 17 from the upper box 6, as can be seen particularly well from FIG. 2. The guide sleeve 17 is arranged on the underside of the upper box 6 directly below that area of the winding spindle 10 on which the elevator rope 20 loops around it twice, and is directed onto the winding spindle 10 at right angles to its axis 11. The guide sleeve 17 is arranged in the area between a possible radial and a possible tangential position. How Fig. 2 shows, both sections 20 ', 20' of the elevator rope 20 are deflected to a common parallel strand.

The first section 20 'of the elevator rope 20 now runs from the winding spindle 10 directly to a hollow lower bar 22 which is attached to the lower edge of the curtain 2, not shown. For this purpose, a bore 26a is formed on the side of the lower bar 22 facing the first holding bar 4, through which the first section 20 'of the elevator rope 20 is guided, deflected there into the cavity of the lower bar 22 and fastened within the cavity to the inner wall of the lower bar 22.

The second section 20˝ of the elevator rope 20 also runs from the winding spindle 10 through the bore 26a of the lower bar 22, but is then led out again through a further bore 26b provided on the lower bar 22 relative to the bore 26a to a second retaining bar 18. The second holding bar 18 is arranged at a distance from the first holding bar 4 and the lower bar 22 within the distance between the two holding bars 4, 18. The second retaining strip 18 is hollow and contains a deflection roller 24, on which the second section 20˝ of the elevator rope 20 is deflected by 180 °. From there runs the second section 20˝ of the elevator cable 20 to the lower bar 22, is again guided through the bore 26b there and deflected behind it in the cavity of the lower bar 22 and firmly connected to the end 21b of a tension spring 28 which is connected to the other end at the Inner wall of the bottom bar 22 is fixed (see. Fig. 1).

Both sections 20 ', 20' of the elevator rope 20 are - as already mentioned - parallel to each other and are guided together in alternating order from the front and the back of the curtain 2 through holes 30 formed in the folding slats. In order to ensure proper back and forth movement of the lower bar 22 and thus the curtain 2 and thereby also secure wrapping of the elevator rope 20 around the winding spindle 10 and also to reduce the load on the elevator rope 20 due to transverse forces occurring, there is between the two retaining bars 4, 18 a guide rope 32 tensioned, as shown in Fig. 1. For this purpose, two holes 34 are provided at the corresponding point of the lower bar 22, through which the guide cable 32 runs. Furthermore, 20 holes 36 are arranged in each folding lamella of the curtain, through which the guide rope 32 is passed in the same alternating sequence as the elevator rope 20 from the front and the back of the curtain 2.

The inventive looping of the elevator rope 20 around the winding spindle 10 along its threads creates a frictional connection between the elevator rope 20 and the winding spindle 10, so that when the winding spindle 10 rotates, the elevator rope 20 is carried around its circumference and the lower bar 22 fastened to the elevator rope 20 with the curtain 2 is moved back and forth. The frictional engagement between elevator rope 20 and winding spindle 10 can be adjusted by the tension spring 28, which causes tension in the elevator rope 20. Nevertheless, the frictional connection between the elevator rope 20 and the winding spindle 10 is only so strong that the elevator rope starts from a certain load 20 is no longer carried along by the winding spindle 10, ie the winding spindle 10 slips under the elevator rope 20. This is the case, for example, if the lower bar 22 is prevented from moving freely, for example if it is held firmly or is hooked on the guide rope 32. Thus, the so-called "slip clutch effect" between the winding shaft 10 and the elevator cable 20 is achieved by the looping according to the invention.

According to the invention, a shutdown unit 38 is provided so that the lower ledge 22 guided by the elevator rope 20 does not hit the first holding ledge 4 when moving up and does not hit the second holding ledge 18 when it is moving down, but rather stops shortly before the holding ledges 4, 18, which is shown in Figs. 3 and 4. The shutdown unit 38 is also housed in the upper box 6 and has a threaded spindle 40 which is rotatably mounted in two bearings 41a, b. The two bearings 41a, b are attached to the inner wall of the upper box 6. The threaded spindle 40 is mechanically firmly coupled to the winding shaft 14, which in turn - as already mentioned - is driven by an electric motor, not shown, which works in both directions of rotation.

Two threaded bushings 44a, b are screwed onto the threaded spindle 40, to each of which a switching cam 42a, b is detachably fastened. For releasable attachment to the respective threaded bushing 44a, b, each switching cam 42a, b has two clamping jaws 42 ′, 42˝ connected by a clamping screw 46a or 46b, between which the threaded bushing 44a or 44b is clamped, as is particularly well shown in FIG. 4 can be seen.

As is also shown in Fig. 4, each switching cam 42a, b at a distance from each other support feet 45 ', 45˝. With these support feet 45 ', 45˝ each switching cam 42a, b is supported on the inner surface 43 extending parallel to the threaded spindle 40 from the top of the upper box 6. This arrangement enables an axial movement of the two switching cams 42a, b when the threaded spindle 40 rotates, since the switching cams 42a, b cannot rotate due to the support on the inner surface 43.

Two switches 48a, b, which are connected in the supply lines 39, are fastened to the rear wall of the upper box 6. The two switches 48a, b are arranged adjacent to the threaded spindle 40 in such a way that a switching cam 42a or 42b can be brought into engagement with an actuating element 49a or 49b of a switch 48a or 48b for actuating the switching contact. Then each switching cam 42a or 42b presses down the actuating element 49a or 49b when the associated switch 48a or 48b is passed over. 4, the position of the switching cam 42a with respect to the actuating element 49a of the switch 48a is shown particularly well. It can be seen here that the actuating element 49a is covered by the engagement area 50 of the switching cam 42a. In order to enable a "gentle" engagement and thus a uniform and safe pressing down of the actuating elements 49a, b, the engagement region 50 of each switching cam 42a, b is slightly bent on both sides in the direction of movement.

Both switching cams 42a, b are arranged between the actuating elements 49a, b on the threaded spindle 40 such that the distance between the two switching cams 42a, b is smaller than the distance between the two actuating elements 49a, b, with both switching cams 42a, b being within the two actuating elements 49a, b are located (see FIG. 3). In this way it is achieved that only one switching cam 42a or 42b can be brought into engagement with the actuating element 49a or 49b of the associated switch 48a or 48b. Both switches 48a, b serve to switch off the electric motor (not shown), namely the one switch when the lower bar 22 is in an upper position below the first holding bar 4 (cf. FIG. 1) and the curtain 2 is thus gathered. and the other switch when the lower bar 22 is in a lower position directly in front of the second holding bar 18 (cf. FIG. 1) and the curtain 2 is thereby completely pulled out. The difference between the distance between the two actuating elements 49a, b relative to one another is proportional to the smaller distance between the two switching cams 42a, b relative to the displacement path of the lower bar 22 between the upper and the lower position (cf. FIG. 1). While the distance between the two actuating elements 49a, b is fixed by corresponding fastening of the switches 48a, b, the position of both switching cams 42a, b on the threaded spindle 40 and their distance from one another can be freely adjusted. For this purpose, only the clamping screw 46 needs to be loosened somewhat for each switching cam 42a, b, as a result of which the threaded bushing 44a and 44b of the two clamping jaws 42 ', 42˝ (see FIG. 4) does not is held more firmly and is therefore freely rotatable on the threaded spindle 40 relative to the associated switching cams 42a or 42b and is displaceable along the latter. Thus, the position of the switching cams 42a, b and thereby the times when the electric motor is switched off can be precisely adjusted and set. Since the two switches 48a, b switch off the electric motor and are thus intended to interrupt the current in the supply lines 49 leading to the electric motor, they are designed as opening pushbuttons.

According to the embodiment shown in FIGS. 1 and 2, the elevator device is arranged on the top of the curtain 2 and the lower bar 22 can be moved downward with the curtain 2; however, it should be pointed out that the elevator device is arranged just as well on the lower edge of the curtain, the lower bar is attached to the upper edge of the curtain and thus the curtain can be moved upwards or that the curtain can also be attached in a horizontal position.

Claims (15)

1. Raising device for a blind, in particular a roller blind or a folded or slatted blind, having

   - two holding parts (4, 18) which are to be mounted fixed and of which the first holding part (4) holds the blind (2) and the second holding part (18) is arranged at a spacing from the first holding part (4), the blind (2) being movable to and fro between both holding parts (4, 18),

   - a winding spindle (10) which has an external thread (12) and which is mounted to be rotatable at least in one bearing (16) containing an internal thread, the external thread (12) of the winding spindle (10) being in engagement with the internal thread of the bearing (16), and having

   - at least two raising ropes (20), of which each is secured to a guide element (22) which is fixedly connected to the blind (2), and of which each is guided directly onto the winding spindle (10) by means of a first portion (20′) and is guided as far as the second holding part (18) by means of a second portion (20˝) and with a deflection (24) is guided from there parallel to the first portion (20′), also onto the winding spindle (10), and of which each engages in the thread turns thereof,

   characterized in that
      - the first portion (20′) of each raising rope (20) merges in one piece into the second portion (20˝) at the winding spindle (10), wrapping fully around the latter at least once.
2. Device according to Claim 1, characterized in that both portions (20′, 20˝) of each raising rope (20) run directly next to one another between the first holding part (4) and the guide element (22) and are guided together through a guide tube (17) in the first holding part (4).
3. Device according to Claim 1 or 2, characterized in that the two free ends (21a, 21b) of each raising rope (20) are secured to the guide element (22).
4. Device according to one of Claims 1 to 3, characterized in that the raising ropes (20) are under tensile stress.
5. Device according to Claims 3 and 4, characterized in that at least one end (21a; 21b) of each raising rope (20) is connected to the one end of a tensioning spring (28) which is secured by means of its other end to the guide element (22).
6. Device according to Claim 5, characterized in that the guide element (22) is constructed as a hollow rod, the two free ends (21a, 21b) of each raising rope (20) are guided through bores (26a, 26b) made in the wall of the guide element (22) and are deflected within the guide element (22), and in that the tensioning spring (28) is arranged within the guide element (22).
7. Device according to one of Claims 1 to 6, characterized by a guide means on which the guide element (22) is mounted displaceably.
8. Device according to Claim 7, characterized in that at least one guide rope (32) is tensioned between both holding parts (4, 18) and bores (34) through which the guide rope (32) runs are provided in the guide element (22).
9. Device according to one of Claims 2 to 8, characterized in that the guide tube (17) for each raising rope (20) is arranged fixed adjacent to the winding spindle (10) and is directed towards the winding spindle (10) at a right angle to the axis (11) thereof.
10. Device according to Claim 9, characterized in that the axis of the guide tube (17) is arranged substantially radially with respect to the winding spindle (10).
11. Device according to one of Claims 1 to 10, having an electric motor operating in both directions of rotation for driving the winding spindle (10), characterized by a switch-off unit (38) placed in the supply lines (39) leading to the electric motor, for switching off the electric motor in an upper and a lower position of the blind (2) to be moved by the raising device.
12. Device according to Claim 11, characterized in that

    - the switch-off unit (38) has a threaded spindle (40) which is mounted rotatably fixed at least in one bearing (41a, 41b) and is coupled mechanically to the winding shaft (14),

    - two threaded bushes (44a, 44b) are screwed to the winding spindle (40) and a switching cam (42a; b) is detachably secured to each of them,

    - a guide part (43) is provided by means of which the switching cams (42a, 42b) are in engagement in a manner displaceable parallel to the threaded spindle (40), and in that

    - two switches (48a, 48b) are arranged adjacent to the threaded spindle (40) in such a way that in each case a switching cam (42a; b) can be brought into engagement with an actuating element (49a, 49b) of a switch (48a; b) for actuating the switching contact,

    - the switching cams (42a, 42b) being arranged between the actuating elements (49a, 49b), whereof the spacing from one another is greater than the spacing between the switching cams (42a, 42b).
13. Device according to Claim 12, characterized in that each switching cam (42a, 42b) has two clamping jaws (42′, 42′′) which are connected by a clamping screw (46a; b) and between which the threaded bush (44a; b) is mounted.
14. Device according to Claim 12 or 13, characterized in that the guide part (43) is constructed as a rail having a planar surface which runs parallel to the threaded spindle (40) and with which a side surface constructed appropriately on each switching cam (42a, 42b) is in surface engagement.
15. Device according to Claim 12 or 13, characterized in that the guide part (43) is constructed as a rail having a planar surface which runs parallel to the threaded spindle (40) and with which at least two supporting feet (45′, 45˝) arranged radially with respect to the threaded spindle (40) and spaced from one another on the switching cams (42a, 42b) are in engagement.

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