EP0503161B1 - Roller with slip-clutch - Google Patents

Abstract

The invention relates to a roller shutter, in particular for roof windows, with a winding shaft which is preferably arranged at the top and is designed to be driven by a motor via a slip-clutch, the slip-clutch being designed to act in both directions of rotation. <IMAGE>

Description

The invention relates to a roller shutter, in particular for skylights, with a winding shaft, preferably arranged at the top, which is designed to be driven by a motor via a slip clutch, the slip clutch having release torques which are designed to act differently for both directions of rotation.

Window shutters are increasingly driven by a motor to enable remote control or automatic control of the opening and closing process. In the case of roof windows in particular, automatic closing of the roller shutters controlled by suitable sensors is often necessary in order to prevent the interior from being excessively heated when exposed to sunlight. The electric drives are arranged on the winding shaft, which is usually arranged at the top.

It has been known for some years to equip roller shutter drives for winding with slip clutches. This protects the electric motor from overloads that occur, for example, when the shutter slats are frozen in the closed state.

From CH-PS 662 868 a torque limiting clutch is known, which disengages depending on the direction of rotation with two different torque sizes. Two grooves are used for coupling, in which two springs are provided for snapping into place. Each groove has two flanks, one against each of which the springs come to rest when the clutch is turned. The springs are Z-shaped leaf springs. These feathers are with both of them Inner edges pivotally mounted on the outside in a turned part. The two outer edges of the spring are intended to snap into the grooves. A support is used to support the springs, which guides the springs on both sides in the middle section.

From CH-PS 662 859 an overload protection for roller shutters is known, with which the torque transmitted to the roller shutters in both directions, i.e. adjustable both for opening and for closing the roller shutter. For this purpose, the overload protection device has two disc-shaped coupling members which are located coaxially under spring force and have frontal toothing. The toothing can have uneven tooth flank angles so that torques of different sizes can be transmitted depending on the direction of rotation. Furthermore, the noise and wear can be kept extremely low with an asymmetrical number division.

The invention was based on the object of specifying a roller shutter of the type mentioned at the outset, in which a slip clutch acting to different degrees in both directions of rotation is realized in a structurally particularly simple manner.

This object is achieved with the roller shutters of the type mentioned at the outset in that the slipping clutch consists of two partial clutches, each part having a release torque only in one direction of rotation and the coupled parts being constructed in a rotationally fixed connection in the opposite direction.

The advantages achieved with the invention specified in the main claim consist in particular in that an excessive compression and possible destruction of the roller shutter slats is avoided with a slip clutch acting in both directions of rotation. If, for example, the guide rails of the roller shutter are iced up, the rotary connection between the motor and the winding shaft is released when the roller shutter closes at a predetermined triggering torque. The roller shutter slats are not subjected to excessive stress. The drive motor is also protected against overload. Stopping the engine under load and the associated destruction of the engine is safely avoided.

Due to the fact that the slip clutch has release torques which are designed differently for both directions of rotation, it can be taken into account that the drive torques required for closing or opening the roller shutter are different. When the roller shutter is closed, the rotational movement of the winding shaft is supported by the weight of the unwound roller shutter slats.

Characterized in that the slip clutch consists of two partial clutches, each part having a release torque only in one third direction and the coupled parts being non-rotatably connected in the opposite direction, the release torque for each direction of rotation can be set independently of one another to adjust. Adaptation to different installation conditions, for example different roof pitches, can be carried out easily and quickly on the two partial couplings.

If the slip clutch is arranged within the winding shaft, preferably in connection with a raw motor, an advantageously small-sized roller shutter results. In particular, the roller shutter box can be made extremely slim.

With the configuration according to claim 3, a simply constructed but effectively working slip clutch is specified. By changing the spring tongue or by changing the pretension of the spring tongue, different release torques of the slip clutch can be selected which are adapted to the circumstances.

In a further embodiment of the roller shutter it is provided that several, in particular four, spring tongues are arranged so as to engage in the teeth of the gearwheel. This further improves the functional reliability of the slip clutch. Furthermore, a compensation of the radial forces acting between the spring tongue and the rest wheel is achieved, so that decentration does not occur.

With the embodiment according to claim 5, an advantageous standardization of the components is achieved. This leads to low manufacturing costs and reduces maintenance costs.

Advantageous configurations of the spring tongues are specified in subclaims 6 to 11.

The spring tongue is inexpensively designed as a sheet metal strip. A molded sliding profile supports the function as a bending or buckling bar. Spring tongues arranged symmetrically to one another compensate for the radial forces generated by the spring tongues. The desired release torques can be generated by spring tongues from sheet metal strips of different thicknesses.

With the dimensions and arrangements of the spring tongue described in subclaims 9 to 11, the operational safety of the slip clutch can be further improved.

If the free bending length of the spring tongues corresponds approximately to 0.7 times the pitch circle radius of the ring gear, mutual interference between the spring tongues is avoided in the event of buckling and bending loads, and at the same time sufficient mobility of the spring tongues is ensured.

Characterized in that the spring tongue has a tangential direction to an intended concentric circle around the spring element with a radius of about 0.7 times the pitch circle, the spring tongue is held in a prestressed position from which it is only slightly compressed when subjected to buckling until the spring tongue partially abuts the internal toothing of the ring gear and a rotationally fixed connection is established.

In a further embodiment it is provided that the spring tongue has a clamping point which is approximately on an imaginary semicircle above the pitch circle radius of the Ring gear is arranged at the point of engagement of the spring tongue in the toothing of the ring gear. So that the clamping point of the spring tongue with respect to the point of engagement of the free spring tongue end is aligned so that a positive connection with a particularly high holding torque is created when the spring tongue is loaded.

Figur 1

einen Teil eines Längsschnitts einer Wickelwelle eines erfindungsgemäßen Rolladens,

Figur 2

eine Seitenansicht eines ersten Federelements,

Figur 3

eine Draufsicht des in Figur 2 dargestellten Federelements,

Figur 4

einen Längsschnitt eines Übertragungselements mit einem zweiten Federelement,

Figur 5

eine Rückansicht des in Figur 4 dargestellten Übertragungselements,

Figur 6

eine Draufsicht des in Figur 4 dargestellten Übertragungselements,

Figur 7

einen Längsschnitt eines Hohlrades und

Figur 8

eine Rückansicht des in Figur 7 dargestellten Hohlrades.

In the following an embodiment of the invention is described with reference to the drawing. Show it:

Figure 1

part of a longitudinal section of a winding shaft of a roller shutter according to the invention,

Figure 2

a side view of a first spring element,

Figure 3

2 shows a top view of the spring element shown in FIG. 2,

Figure 4

2 shows a longitudinal section of a transmission element with a second spring element,

Figure 5

3 shows a rear view of the transmission element shown in FIG. 4,

Figure 6

3 shows a plan view of the transmission element shown in FIG. 4,

Figure 7

a longitudinal section of a ring gear and

Figure 8

a rear view of the ring gear shown in Figure 7.

FIG. 1 shows a winding shaft 2 which is arranged on an end cover 1 of a roller shutter box and can be driven by a tubular motor 3 fastened to the end cover 1 by screws 4.

On a motor shaft 5, a first spring element 6 shown in Figures 2 and 3 is rotatably connected. The first spring element 6 has a plate-shaped base body 7 and thereon a spring tongue 9 held in the holder 8.

The first spring element 6 is arranged centrally in a first ring gear 11 of a transmission element 10. Depending on the direction of rotation of the motor shaft 5, the spring tongues 9 engage non-rotatably or, depending on the load, engage in an internal toothing 12 of the first ring gear 11 depending on the load.

The transmission element 10 is freely rotatable in a bore 13 on the motor shaft 5. The transmission element 10 consists of the first ring gear 11 and a second spring element 14 with holders 15 and spring tongues 16 held therein, as shown in FIGS. 4, 5 and 6. The spring tongues 16 are oriented opposite to the spring tongues 9 of the first spring element 6.

The second spring element 14 is in turn arranged concentrically in a second ring gear 17 shown in FIGS. 7 and 8. The second ring gear 17 has an internal toothing 18 and a nose 21 formed on the outer circumference. The second ring gear 17 is in a concentric bore 19 on the motor shaft 5 mounted non-rotatably, a nut 20 screwed onto the outer end of the motor shaft 5 holding the partial couplings together.

The two spring elements 6, 14 each have four spring tongues 9, 16 distributed symmetrically in the holders 8, 15. The spring tongues 9, 16 are fastened to the holders 8, 15 at clamping points 23. The spring tongues 9, 16 consist of 0.2-0.5 mm thick sheet steel strips, at the ends of which a semi-arc-shaped slide-on profile 24 is formed. This slide-on profile 24 engages in the internal toothing 12, 18 of the associated ring gears 11, 17.

The rotational movement transmitted to the transmission element 10 is transmitted to the second ring gear 17 by means of a second spring element 14. The spring tongues 16 of the second spring element 14 engage in the internal toothing 18 of the second ring gear 17. The spring tongues 16, which are oriented opposite to the spring tongues 9 of the first spring element 6, thus also effect a load-dependent coupling of the second direction of rotation, wherein different release moments can be preselected by different design of the spring tongues 9 or 16. The rotational movement of the second ring gear 17 is transmitted via the nose 21, which engages in a groove 22 in the winding shaft 2, to the winding shaft 2 in the roller shutter box. The winding shaft 2 rolls up and down the roller shutters.

The coupling can also be provided particularly advantageously manually, for example by means of a crank, moving roller shutters. This prevents damage caused by incorrect operation.

REFERENCE SIGN LIST

1

End cover

2nd

Winding shaft

3rd

Tubular motor

4th

screw

5

Motor shaft

6

first spring element

7

Basic body

8th

holder

9

Spring tongue

10th

Transmission element

11

first ring gear

12th

Internal teeth

13

drilling

14

second spring element

15

mother

16

Spring tongue

17th

second ring gear

18th

Internal teeth

19th

drilling

20th

holder

21

nose

22

Groove

23

Clamping point

24th

Sliding profile

Claims (11)

1. Roller blind, in particular for skylights, with a winding shaft (2) which is preferably arranged at the top and is formed so as to be driven by a motor (3) via a slip clutch, the slip clutch having release moments which act to different degrees in the two directions of rotation, characterised in that the slip clutch consists of two partial clutches, each part only having a release moment in one direction of rotation and the coupled parts being formed so as to connect in a non-rotatable manner in the opposite direction.
2. Roller blind according to claim 1, characterised in that the slip clutch is arranged inside the winding shaft (2), preferably combined with a tubular motor (3).
3. Roller blind according to claim 1 or 2, characterised in that the slip clutch comprises a toothed wheel which is preferably formed as an internal geared wheel (11, 17) and in the teeth of which a spring tongue (9, 16) engages, the tongue forming a bending bar in one direction of rotation and a buckling bar in the opposite direction.
4. Roller blind according to claim 3, characterised in that a plurality, in particular four, spring tongues (9, 16) engage in the teeth of the toothed wheel.
5. Roller blind according to claim 3 or 4, characterised in that a toothed wheel, formed as an internal geared wheel, and a spring element arranged concentrically with the latter are associated with each partial clutch, one internal geared wheel (17) being formed so as to be non-rotatable with the winding shaft (2) and one spring element (6) non-rotatable with the motor shaft (5), and the other spring element (14) and internal geared wheel (11) being formed so as to be non-rotatable with one another.
6. Roller blind according to claim 3, 4 or 5, characterised in that the spring tongue (9, 16) is formed as a sheet-metal strip with a preferably moulded rising profile.
7. Roller blind according to claim 3, 4, 5 or 6, characterised in that the spring tongues (9, 16) are arranged symmetrically with respect to one another.
8. Roller blind according to claim 3, 4, 5, 6 or 7, characterised in that the spring tongues (9, 16) are formed from sheet-metal strips of different thicknesses in accordance with their release moment.
9. Roller blind according to claim 3, 4, 5, 6, 7 or 8, characterised in that the spring tongue (9, 16) has a free bending length which corresponds to between half and the entire pitch radius, in particular approximately 0.7 times the pitch radius, of the internal geared wheel (11, 17).
10. Roller blind according to claim 3, 4, 5, 6, 7, 8 or 9, characterised in that the spring tongue (9, 16) extends tangentially to a concentric circle which is imagined about the spring element (6, 14) and whose radius is approximately 0.7 times the pitch circle.
11. Roller blind according to claim 3, 4, 5, 6, 7, 8, 9 or 10, characterised in that the spring tongue (9, 16) has a fixing point (23) which is arranged approximately on an imaginary semicircle over the pitch radius of the internal geared wheel (11, 17) at the point at which the spring tongue engages in the tooth system of the internal geared wheel.

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