EP0127749A2 - Security device against lifting and lamellar blind comprising such a device - Google Patents

Abstract

A stroke safety device for slat blinds is proposed, in which a locking pawl (15) is provided in a movable carriage (5), which is mounted on the carriage (5) in such a way that the distance (ra, rb) from a terminal part (17 ) to the pivot point (19) of the locking pawl lever (15) on the carriage (5) when approaching a 90 ° swivel angle with respect to the carriage displacement direction (H). Stops (25, 27) on the one hand secure the locking pawl lever (15) in the almost 90 ° locking position and cause (27) that the locking pawl lever (15) when released from the locking position by means of a bolt (13) on a blind lifting chain ( 11) is rapidly pivoted away from the counter thrust bearing (7a) by further reducing the swiveling radius of the locking section) 17). In addition, a drive transmission for lowering and lifting and tipping slat blinds is proposed, in which a lowering drive chain (37) runs over a chain wheel. In the lamella tilt position, a cam (105) of the lifting chain (37) engages in a coupling element (41), the displacement of which is thereby rigidly connecting a transmitter (65) to the chain wheel (35). A torsion spring (87) transmits the transmitter movement to a driver (97), to which a drive element (99) for the tipping of the store is attached. The driver (97) acts on a stop (103) on a housing (31) to end the tipping movement, the torsion spring (87) then continuing to rotate the chain wheel (35) due to inaccurate drive element standstill. To prevent damage to the blind, in particular with such a drive transmission, the lowermost lamella (209) is preferably detachably connected to a rocker arm (211) connected to rocker drive elements (213). This with a latching device (217, 219).

Description

The present invention relates to a lift safety device for slat blinds, with one, at least with one of the slats for lifting and lowering movements, motion-coupled, linearly moving along stationary frame parts of the store, and at least one pawl lever pivotable in the store lifting plane on the carriage, the locking of which by With carriage stroke, there is a linear pivot point shift on the carriage and terminal frictional contact with frame parts, as well as a drive transmission for lowering and raising a slat blind and a rotation protection device for slats of slat blinds and a roman blind with at least one of the devices mentioned.

• Bedingt dadurch, dass der Hebel bezüglich der Storen-Hubrichtung schiefwinklig geneigt ansperrt, besteht die Möglichkeit, die Sicherung durch Vibrieren des Wagens nach und nach aufzuheben. Einer Dimensionierung des Hebels so, dass er durch fortgesetztes Anheben des Wagens schliesslich in eine mit Bezug auf die Storen-Hubrichtung stabilere senkrechte Lage gedrückt wird, steht entgegen, dass dann die Ausdehnung der Hebellänge sehr genau auf den Abstand zwischen seinem Schwenkpunkt am Wagen und Ansperr-Führungspartie abgestimmt werden muss, um die Klinke überhaupt sichernd in diese Lage schwenken zu können. Anderseits sind an den Wagenführungen grosse Toleranzen, was die Masse und die Oberflächenbeschaffenheit angelangt, in Kauf zu nehmen, die eine derartige Auslegung des Ansperrhebels problematisch machen.

From DE-OS-30 37 733 such a stroke safety device is known, in which a locking lever is provided on a longitudinally displaceable carriage in guides to prevent unauthorized lifting of the slats on a slat blind, the length of which is greater than the distance between its pivot point on the carriage and the section of guides for the carriage intended for intervention. At unauthorized lifting of the trolley, i.e. not with a drive device provided for lifting or lowering the store, the lever provides for the corresponding carriage guide and locks against it. It remains in an inclined position with respect to the stroke direction. This stroke safety device has the following disadvantages:

• Due to the fact that the lever locks at an oblique angle with respect to the blind stroke direction, it is possible to gradually release the safety device by vibrating the carriage. A dimensioning of the lever so that it is finally pushed into a more stable position with respect to the direction of the stroke by continuing to lift the carriage, is then opposed by the fact that the length of the lever then extends very precisely to the distance between its pivot point on the carriage and the lock - Guide section must be coordinated in order to be able to pivot the jack securely into this position. On the other hand, large tolerances in terms of mass and surface quality must be accepted on the carriage guides, which make such a design of the locking lever problematic.

The object of the present invention is to design a lift safety device of the type mentioned at the outset in such a way that, largely largely independently of the tolerance dimensions of the stop frame parts, it enables the carriage to be blocked extremely reliably against unauthorized lifting.

This is achieved in that the lever is mounted on the carriage in such a way that the distance from the terminal end portion to the pivot point of the lever on the carriage decreases when the lever pivoting angle is approached by 90 ° with respect to the direction of stroke of the blind.

These measures ensure that the lever can be pivoted into the 90 ° position regardless of its excess with respect to the distance between its pivot point on the carriage at the beginning of the locking pivot and the counter bearing on the housing and there blocks the carriage. To take the 90 ° position mentioned by the lever, a maximum contact pressure force is exceeded on its swivel path, so that it practically snaps into the 90 ° position mentioned.

To achieve the reduction in distance mentioned, the lever is preferably mounted on the carriage by means of a pin-groove connection, the groove being defined by a curve which is given by vectors with respect to the connecting part, the amount of which decreases with increasing position angle in the opposite stroke direction.

In order to further prevent the lever from being pivoted beyond the 90 ° position mentioned when the car is pushed up, it is proposed to provide a stop for the lever on the car.

Is the carriage and therefore the bottom blind slat connected to it preferably as described has been lifted up and clamped by the action of the lever, it is essential that when the store and then the trolley are subsequently raised by means of a lifting drive, such as with a lifting line or lifting chain, the lever is pivoted out of engagement with the frame parts in the shortest possible way. This rapid swiveling must also be ensured, taking into account unevenness and tolerance dimensions of the frame parts to which the lever locks.

This is achieved in a lift safety device of the type mentioned, the lever being able to be coupled between storage on the carriage and a docking section with a stroke drive for the store, in that a stop is provided on the carriage, to which the lever engages at least almost when a pivot position is assumed 90 ° with respect to the stroke direction in this direction, with the coupling of the lever and drive between this stop and the locking part, such that the lever pivots at least for the time being when pivoting up from the locking by means of the drive about this stop.

As a result, at least at the beginning of the pivoting back movement of the lever, the latter is rotated by the abovementioned stop, which defines a shortened turning radius with respect to the pivoting radius between the locking part and the lever bearing on the carriage, thus increasing the lifting component of the locking part. This rotary stop also ensures that the lever returns to a position when the carriage is pressed down in the locked position larger swivel radius is moved so that the 90 ° lever position is stabilized.

In order to improve an engagement of the locking part with the corresponding frame part at the beginning of the pivoting movement of the lever for locking, it is also proposed that the locking part of the lever is designed as an edge.

The present invention further relates to a drive transmission for lowering and raising a slat blind, by means of a first belt-like element and for tilting the slats by means of a second belt-like element, the first element running on a drive element, the second on a driver arrangement which is rotatably mounted for this purpose is stored.

Such an arrangement is known from the above-mentioned DE-OS 30 37 733. A drive edge driven on an axis for an elevator belt for lowering or. Pulling up the store is connected via a spiral spring, which is arranged on the circumference of the axis, to a driver arrangement, which comprises a sleeve, which is located above the spiral spring and is coaxial to the axis. The spiral spring acts as a friction clutch between the drive wheel and the driver arrangement as long as the spring ends projecting through the driver arrangement bush do not act on stops. The intended stops are introduced into the path of the spring ends acting as counter-stops in such a way that the torsion spring when it is opened or closed. Lowering the store strikes, however _' in the case of blind positions in which a change in the inclination of the slats is to be controlled, whereby the driver arrangement rotates with the drive wheel.

This arrangement has the disadvantage, in addition to a relatively complicated structure, that with normal raising and lowering of the store, the friction between the drive axle of the wheel and the named spring, which occurs when the torsion spring is non-rotatably attached, has to be permanently overcome.

This leads to the fact that an intended drive unit is to be designed taking into account this friction, which must not be less than a certain amount, in view of the fact that it is precisely this friction that has to bring about the rotary connection between the drive wheel and driver arrangement.

The present invention now aims to remedy the disadvantage mentioned in such a drive transmission and to design it so that the drive element for a first belt-like element, such as an elevator or. Lowering line, with a driver arrangement for a second belt-like element, such as another line for tilting the slats, is connected.

• - ein durch mindestens einen Mitnehmer einerseits an das erste Element, dadurch anderseits an einen Uebertrager koppelbares Kopplungselement,
• - mindestens eine zwischen Uebertrager und Mitnehmeranordnung durch Relativdrehung dieser Teile spannbare Federanordnung,
• eine den Drehweg der Mitnehmeranordnung bezüglich einer drehfesten Gehäusepartie mindestens einseitig begrenzende Drehanschlaganordnung,

derart, dass die Bewegung des ersten Elementes nach Durchlaufen einer vorgegebenen Position, via Mitnehmer, Kopplungselement, Uebertrager, Federanordnung sich auf die Mitnehmeranordnung bis zu einer durch die Drehanschlaganordnung festgelegten Drehposition überträgt, wonach sich die Federanordnung federnd einer Relativdrehung von Antriebsorgan und Mitnehmeranordnung widersetzt.For this purpose, the drive transmission is characterized in that the following are provided:

• a coupling element which can be coupled to the first element by at least one driver, and thereby to a transmitter, on the other hand,
• at least one spring arrangement which can be tensioned between the transmitter and driver arrangement by relative rotation of these parts,
• a rotary stop arrangement which limits the rotation path of the driver arrangement with respect to a rotationally fixed housing part,

such that the movement of the first element after passing through a predetermined position, via driver, coupling element, transmitter, spring arrangement, is transferred to the driver arrangement up to a rotational position defined by the rotary stop arrangement, after which the spring arrangement resiliently opposes a relative rotation of the drive member and driver arrangement.

The spring arrangement thus remains completely inactive when the transmitter is not coupled to the first element, ie when the store is raised and lowered normally. Only when the aforementioned first element is coupled to the transmitter via the driver, the latter acts on the spring arrangement, is the driver arrangement also moved via the spring arrangement without, however, tensioning of the spring being used, because there is also no relative rotation between the transmitter and driver arrangement , both of which run with the drive member. Only when in one or the other direction of rotation arre one of the rotational travel of the driver arrangement ting stop organs is reached, the driver assembly is rotationally fixed, with any further moving transmitter. Now the spring arrangement is tensioned and in this phase acts as a leakage protection in that usually a drive provided, such as an electric motor, does not come to a standstill for the drive element in an exactly predetermined angular position.

The coupling element preferably comprises at least one engagement element mounted on the transmitter, which protrudes into the movement path of at least one driver on the first element. By providing such an engagement element which interacts with the first element, a pivoting movement of the slats, for example in the raised or lowered blind position, is achieved by providing two engagement elements, for example in both of the above-mentioned positions.

It is further proposed that the coupling element be displaceable on the transmitter, preferably spring-loaded, and engage in a predetermined position with the housing and be displaceable from this position by the driver.

This locking connection of the coupling element and housing ensures that any torques transmitted by friction to the transmitter remain ineffective as long as they are not actuated by a driver.

A simple construction results from the fact that the coupling element comprises a slide, preferably spring-loaded slide, which is guided radially on the transmitter, and an indentation or indentation which engages in a predetermined rotational position with corresponding shaping or shaping, the tangent at least in the rotational position of the driver acts approximately parallel to the slide guide on the transmitter on the slide.

It is further proposed that the transmitter include a cylinder sleeve located above a drive shaft for the organ, as well as the driver arrangement, with a torsion spring inserted between them as a spring element.

As already mentioned, the torsion spring arranged in this way results in a torsion coupling between the transmitter and driver arrangement, which is only tensioned when the relative rotation of these two parts is forced.

The provision of a torsion spring has the further advantage that tensioning can take place in both relative directions of rotation of the transmitter and driver arrangement, with the result that an anti-rotation device in the aforementioned sense is realized in both drive directions of a drive unit provided, such as an electric motor.

From the statements made above, it can be seen that with such a drive transmission, a practically rigid rotary connection of the drive element for raising and lowering the blind and the driver arrangement, the latter for tilting the slats is realized.

In particular, if the individual slats are now positively connected to one another for tipping, the problem arises that when e.g. Damage to the store can be caused by placing the bottom blind slat on any object which prevents the tipping movement and whose pivoting is impossible. Especially in this context, but also in other applications at most, a further aspect of the present invention proposes a rotation protection device for slats of slat blinds, in which the slats on the slat holders on the side can be lowered and raised, also tilted, and for the latter, the holder is connected to a tilting arrangement in which the tilting arrangement for the slat can be pivoted about the tilting axis relative to the slat holder, a release device responding to a predetermined tilting moment being provided between the tilting arrangement and the holder.

By providing the relative pivotability of the tilting arrangement and the slat holder, the possibility is basically created that the tilt drive connection to the slat is released, which prevents the slat from pivoting when the slat is in line, when the predetermined tilting moment is reached on the tilting arrangement on the slat and then released Relative pivotability mentioned is realized, which then the tilting arrangement on the upcoming slat, like the other slats, the pivoting movement, respectively. Can perform tilting movement without this affecting the prevented slat.

The release device is preferably designed as a latching arrangement between the holder and the tilting arrangement, e.g. in the form of a latching connection.

Furthermore, it is proposed that the tilting arrangement be resiliently tensioned against a relative pivoting with respect to the slat holder, which makes it easier to re-engage and when the pivoting obstacle on the slat is removed, the latter is at least almost driven into the intended tilting position when the pivoting obstacle is removed. Furthermore, the lamella holder and the tilting arrangement are preferably axially braced against one another by a Federogan, whereby firstly when the rotary connection between the tilting arrangement and the lamella holder is released, the flap is largely prevented from fluttering, such as under the influence of wind, and secondly such fluttering is prevented when the tilting arrangement not by the tilt drive, like scissor links, is rotationally stabilized, which is the case when the lamella is raised by a lifting drive and the tilt drive is thus loose.

All of the inventive measures mentioned, the stroke safety device, the drive transmission and the anti-rotation protection device are preferably used together a Roman blind is provided or in a desired combination, whereby, as already mentioned, the provision of the anti-rotation lock is forced together with the drive transmission.

The invention is subsequently explained, for example, using figures.

• Fig. 1 eine Seitenansicht, teilweise geschnitten, einer erfindungsgemässen Hubsicherung, mit in Ansperrposition schwenkendem Sperrhebel an einem storenendständigen Wagen,
• Fig. 2 eine Darstellung gemäss Fig. 1 zur Erläuterung der Hebelbewegung bei Rückschwenken,
• Fig. 3 einen Längsschnitt durch eine erfindungsgemässe Antriebsübertragung,
• Fig. 4 einen Schnitt gemäss Linie IV - IV von Fig.3 durch eine erfindungsgemässe Antriebsübertragung,
• Fig. 5 eine Seitendarstellung einer erfindungsgemässen Drehverzugsicherung,
• Fig. 5a eine Prinzipdarstellung einer Einrastverbindung an einer Drehverzugsicherung gemäss Fig. 5,
• Fig. 6 eine Schnittdarstellung durch die Drehverzugsicherung von Fig. 5.

Show it:

• 1 is a side view, partly in section, of a stroke safety device according to the invention, with the locking lever pivoting in the locking position on a stop-end carriage,
• 2 shows a representation according to FIG. 1 to explain the lever movement when swiveling back,
• 3 shows a longitudinal section through a drive transmission according to the invention,
• 4 shows a section along line IV-IV of FIG. 3 through a drive transmission according to the invention,
• 5 is a side view of an anti-twist device according to the invention,
• 5a is a schematic diagram of a snap-in connection on a anti-twist device according to FIG. 5,
• 6 is a sectional view through the anti-twist device of FIG. 5.

A carriage 5 is mounted in a linearly displaceable manner in a store housing 1, for example guided with four pairs of rollers 3. In parallel to carriage guides 7 on the housing 5, chain guides 9 are provided on the carriage 5 in the form of upstanding plates, between which a chain 11 is displaceable. Since the chain 11 lies in front of the figure level in the representations of FIGS. 1 and 2, it is only shown in broken lines. The chain 11 carries at its end a driver cam 13, which cooperates with a locking lever 15, which has a locking edge 17 at the end, and is mounted on a trunnion 19 on the carriage 5. The lever 15 extends from one side of the carriage through corresponding cutouts in the chain guides 9 to the area of the one carriage guide 7a, hereinafter referred to as the locking counter bearing. The lever 15 rides in a guide groove 21 on the bearing pin 19. The groove is bent in a kidney shape and has a width corresponding to the bearing pin diameter over its entire length, the groove center line m being fixed with reference to the locking edge 17 on the lever 15 by location vectors r, the amount of which decreases as the angle IP increases in the opposite stroke direction GH. The pivotability of the lever 15 is limited in the counterclockwise direction by a limit stop 25 on the carriage 5. Immediately in the area of the upper edge 16 of the lever 15, a rotary stop 27 is provided on the carriage 5, the function of which will still be discussed.

The illustrated lifter works as follows:

Together with the lowest slat of a slat blind, not shown, which is pivotally connected to the slat bearing journal 23 with the carriage 5, as shown schematically, the carriage 5 is raised or lowered by means of the lowering and lifting chain 11 by the driving cam 13 on the chain 11 is present at a recess 29 of the lever 15. In this normal lifting and lowering operation, the store resp. the carriage 5, the lever 15 is against the rotary stop 27. If the lowest blind lamella fastened to the lamella bearing journal 23 is impaired in its lowering movement in the direction of GH when lowering the store and thus the carriage 5, for example by an object standing in the movement path, the chain 11 continues to run downwards and the driving cam 13 out of the recess 29 out on lever 15. Thus, the lever 15 assumes the position shown in FIG. 1, it tilts counterclockwise until its locking edge 17 rests on the locking counter bearing 7a. If the blocking object is removed from the path of movement of the lowest slat, the carriage falls until it rests on the driving cam 13.

If an attempt is made in any position to lift the carriage 5 and thus the store with the lowest slat in the direction H, the lever 15 passes through the positions a, b, c shown in dashed lines in FIG. 1. In a first swiveling range, it rotates around the bearing journal 19, the locking edge 17 tending to form an arc around this journal with the radius r _a crosses out. As the trunnion 19 is pushed upwards in a linear movement when the trolley 5 is lifted and the radius r is greater than the a distance between the trunnion 19 and the locking counterbearing 7a, the lever 15 wedges along the guide groove 21 and thus forces the lever 15 to pivot in the direction indicated by A. The locking edge 17 forms the fulcrum. As a result of this forced pivoting up of the lever end with the groove 21 in direction A, the bearing pin 19 slides into the lower guide groove region, which has a reduced distance r _b with respect to the locking edge 17. Finally, the lever 15 comes to lie in a practically rectangular position with respect to the stroke direction H.

Taking into account that with this pivoting the locking edge 17 remains largely stationary on the counter thrust bearing 7 and only rolls under pressure, it can be seen that to pivot the lever 15 down into this right-angled position, a lifting force must be applied to the carriage 5 against this position decreases. A further downward pivoting of the lever 15 is prevented by the limit stop 25 on the carriage. Due to the pivoting of the lever 15 in its guide groove 21 along the bearing pin 19, the upper edge 16 of the lever comes into contact with the rotary stop 27 when the aforementioned 90 ⁰ end position is assumed.

In Fig. 2 it is shown how the lever 15 is released when the locking is released by lifting the chain 11 with the driver cam 13. The driver cam 13, viewed in the horizontal direction, acts on the lever 15 between the stop point of the limit stop 25 and the rotary stop 27 on the lever 15. Since, as shown, the guide groove 21 in the 90 ° locking position of the lever 15 in the region 19 receiving the pin is practically vertically oriented, the rotary stop 27 now acts as a fulcrum for the lever 15. Thus, the lever 15 pivots in a first swing-back phase about the rotary stop 27, the locking edge 17 pivoting, at least almost, on a circular path with the radius of curvature r _c around the rotary stop 27. This radius of curvature r _c is significantly smaller than the pivot radii r, r _b , which determine the path of the locking edge 17 when it takes up its locking position. Due to this reduced path radius, the locking edge 17 is pivoted away from the locking contact with the locking counter bearing 7 even with a slight stroke of the driving cam 13. Thereafter, the lever 15 slides in the direction shown by B by now pivoting the guide groove 21 along the bearing pin 19 until the bearing pin 19 is again in contact with the upper guide groove part and the upper edge 16 while pulling the driving cam 13 on the rotary stop 27.

From the arrangement of the rotary stop 27 and the groove position when the 90 ⁰ stop position is taken up by the lever 15, it can be seen that it cannot be easily pivoted back in this position even by pulling the carriage 5 in the direction of GH and there is a relatively stable position occupies.

With the described anti-lift device, an extremely safe precaution against unauthorized lifting of blinds, such as Roman blinds, is realized, with unevenness of the locking counter-part as well as geometrical tolerances of the spacing between bearing pin 19 and this counter-bearing not impairing its safe functioning within wide limits. Thanks to the relatively stable position of the lever 15 in an almost 90 ° locking position, successive loosening of the wedging by vibrations on the carriage 5 is also not possible.

3 and 4, the drive transmission according to the invention is shown. A hollow shaft 33 is rotatably mounted in a housing 31, which is non-rotatably mounted on the blind housing, in the cavity of which a drive shaft, not shown, of a drive for the store is axially inserted and fixed. On one end face, the hollow shaft 33 carries a sprocket 35, on which a chain 37 runs in a driven manner analogous to the chain 11 of FIGS. 1 and 2 and extends downwards on both sides. The chain 37 drives the store for lifting and lowering movements. As can be seen in particular from Fig. 4, is located axially, by a washer 39 on the sprocket 35 then, on the hollow shaft 33, a slider 41. In _F ig. 4, the chain 37, lying in front of the figure level, is entered with dashed lines. The slide 41, acting as a coupling element between the sprocket 35 on the hollow shaft 33 and the transmitter to be described below, comprises the hollow shaft 33 with a center opening 43. Its upper edge 45 and its side edges 47 span a rectangular figure. The lower edge _49 is formed by two bearing surfaces 51 that protrude from the side edges 47, thereupon an arcuate boundary 53 is formed with a radius of curvature corresponding to the outer radius of the hollow shaft 33, a guide groove 55 being incorporated vertically downward in the circular boundary 53 in the vertical axis of symmetry of the slide 41. A generally trapezoidal stop 57 projecting downward is provided on the slide 41, on the stop surfaces 59 of which each chain pin receptacle 61 adjoins on both sides. The housing 31, aligned axially with the stop 57, has a receiving opening 63 for the stop 57.

Axially adjoining the slider 41 is a _U boar exchanger 65 is provided, as can be seen in particular from Figure 3, rides the rotatable on the hollow shaft 33 and axially faces the slider 41, jumping up one of a hollow shaft portion 67, the disc-shaped flange 69 bears . The slide 41 slides on the guide surface 71 of the flange 69 facing it. This guide surface 71 has a guide formation 73 which projects into the center opening 43 of the slide. As can be seen in particular from FIG. 4, this shape 73 is designed such that, on the one hand, vertically aligned with the bearing surfaces 51 on the slide 41, counter bearing surfaces 75 for springs 77 are formed. Aligned with the guide groove 55 of the slide 41, a torque transmitter cam 79 is integrally formed on the formation 73 for engagement in the groove 55. As can again be seen from FIG. 4, the slide 41 can and will be pushed up and down linearly in the vertical direction pressed by the springs 77 into the lower position shown in dashed lines in this figure. When the slide 41 is pushed up, the torque transmission cam 79 slides further into the guide groove 5.5. The outer edge of the slide 41 is otherwise designed so that, pushed into the upper position shown in FIG. 4, it nowhere projects beyond the flange 69 of the transmitter 65.

Adjoining the transmitter 65 axially, a tilt drive bushing 81 is provided which, on the one hand, is rotatably supported on a part of the hollow shaft 33, and on the other hand axially projects beyond the hollow shaft section 67 of the transmitter 65 with an outer cylinder wall 83, such that a closed one is provided between the transmitter 65 and the tilt drive bushing 81 Receiving chamber 85 is formed, in which a torsion spring 87 is mounted. One end 89 of the torsion spring 87 lies in a radially projecting manner in a driver groove 91, machined axially into the outer cylinder wall 83, the second end of the torsion spring 93 in a recess 95 on the side of the flange 69 facing away from the slide 41. The driver groove 91 and the recess 95 formed so that the torsion spring ends are locked in both directions of rotation with more or less play. On the outer cylinder wall 83 of the tilt drive bushing 81, a fixation 97 is provided for a tilting drive belt 99 encircling the tilting drive bushing 81, the latter being the pivoting or. Tilting the blind slats drives. Furthermore, a stop 101 sits on the outer cylinder wall 83, which interacts with the rotational mobility of the tilt drive bush 81 with respect to the housing 31 limited with counter-stop surfaces 103 provided on the housing inner wall in both directions of rotation.

The function of this drive transmission is as follows: To raise or lower the slat blind, the chain 37 is driven via hollow shaft 33, sprocket 35. The slider 41 is driven by the springs 77 into the lower position shown in dashed lines according to FIG. 4, with which its stop 57 projects with the stop surfaces 59 into the receiving opening 63 of the housing 31 and any rotational movement of itself, and thus of the subsequent transmitter 65 and the tilt drive bush 81 prevented with respect to the housing 31. Shortly before the store is lowered to its lowermost position, a chain end cam 105, in the lowering direction C of chain 37 shown in FIG. 4, engages in the corresponding chain pin follower 61 of slide 41, after which the latter counteracts as the chain continues in direction C. Effect of the spring 77 is raised such that its stop 57 disengages from the receiving opening 63 on the housing 31. During this pushing up of the slide 71, the torque transmitter cam 79 on the transmitter flange 69 is also pushed completely into the guide groove 55 of the slide, so that the movement of the continuing chain 37 via end cams 105, slide 41, groove-cam connection 55, 79 is now on the Transmitter 65 transmits directly. The rotary movement of the transducer 65 which now begins is transmitted further via boundary surfaces of the recess 95 to the one torsion spring end 93, then via the torsion spring 87, in particular its second end 89, the corresponding boundary surface of the groove 91, to the tilt drive bushing 81, whereupon via fixation 97 the tilt drive belt 99 a tilt. Swiveling the blind slats causes. The torsion spring 87 acts with a correspondingly designed spring constant between the transmitter 65 and the tilt drive bushing 81 as a practically rigid rotary connection. The pivoting of the tilt drive bush 81 ends when the stop 101 on the outer cylinder wall 83 hits the counter stop 103 on the housing 31. The relative angular position of these two organs is such that the slats are tilted by the required amount in the stop position, so that further tilting must be prevented. This is done by the mechanical stop mentioned. Since a drive element provided, for example an electric motor, which acts on the sprocket 35 via the hollow shaft 33, cannot usually be brought to a standstill exactly in a predetermined position, but instead extends beyond this TARGET position, the torsion spring 87 acts on this drive as Brake and for the entire drive device as overflow protection. With, as described, with respect to the housing 31 rotationally fixed tilt drive bushing 81, the transmitter 65 can still be rigidly connected to the sprocket 35 via slide 41, can be moved against the force of the spring 87, so that a further rotation of the motor does not impair the store and the Drive transmission can result.

The restoring force of the spring 87 rotates when the drive motor has come to a standstill, the shaft of which returns by the overspeed path. The analogous processes take place when the blind slats arrive, for example in the upper blind position, by a not shown Chain start cams, analogous to 105, engages in the second chain pin receptacle 61, whereupon the same connection sequences are inserted in the opposite direction of rotation.

The structure of the drive transmission described is relatively simple and compact, with practically no additional load torques being generated for the drive motor, except for those which have to be overcome anyway for lowering / raising and tilting the slat blind. _Z Udem is realized an overflow protection for the motor.

In particular, when the drive transmission described is used, in which the tilt drive for the slats is practically rigidly connected to the blind drive, for example an electric motor, there is a risk that if e.g. the lowest disturbing lamella is impaired in its pivoting movement by any object, the store is damaged.

In order to counteract this danger, a rotation protection device described with reference to FIGS. 5 and 6 is proposed according to the invention. According to FIG. 5, the anti-twist device comprises an assembly part 201 which, for example, when this anti-twist device is provided for the lowest blind slat, as shown schematically, is fastened to a blind end carriage 205 that can be linearly moved up and down in guides on the blind housing. On this mounting part, a pivot pin 207 for a blind slat 209 shown in dashed lines is carried out in a rotatable manner, a rocker arm 211, also rotatably movable, riding on the pivot pin 207. Grip the two ends of the rocker arm as shown schematically at 213, tilt drive elements 211 of the store, for tipping the slats, such as tension belts or scissor links. As can be seen in particular from FIG. 6, on the side opposite the lamella 209, the mounting part 201, a driver 215 is rigidly connected to the bearing pin 207 projecting through the mounting part 201. On the driver 215, a latch projection 217 is formed, which resiliently snaps with corresponding pivoting of the carrier 15 and thus the fin 209 relative to the _K IPP lever 211 in a thereto correspondingly formed pawl 219th 5 shows the position of the rocker arm 211 of the slat 209 and thus also of the driver 215 when the pawl connection 217, 219 is engaged between the slat 209 and the rocker arm 211. This pawl connection primarily creates a rotary connection between rocker arm 211 and lamella 209, so that the rocker arm 209 can be pivoted in the direction shown by β with the rocker drive elements 213, acting on the rocker arm 211.

If the pivoting movement of the lamella 209 is made impossible by an obstacle shown schematically at 221 and the tilting moment acting in the direction β and exerted by the tilting drive elements 213 on the rocker arm 211 rises above a predetermined amount, the pawl connection 219, 217 snaps out and outputs it Rocker arm 211 without taking the slat 209 free for the tilting movement in the direction β.

5a schematically shows a possible design of the pawls 217, 219. The driver 215 is preferably made of plastic, the torque required to release the coupling between the lamella 209 and the rocker arm 211, in addition to the pawl shape, also being determined by the elasticity of the pawl material on the resilient pawl 217 on the driver side. A torsion spring 223 supported on the one hand on the rocker arm 211, on the other hand on the driver 215, once the rotary connection of the rocker arm 211 and driver 215 has been loosened, for example when removing the obstacle 221, pivots the lamella 209 into the tilt position assumed by the other lamellas which are not swivel-inhibited.

As can also be seen in FIG. 6, the rocker arm 211 and the lamella 209 with the mounting base 201 are axially resiliently clamped with a plate spring 225, so that even when the connection between the lamella and the rocker arm 211 is released, the former is mounted such that it is damped against pivoting vibrations such that at the store intervening wind can not be excited to flutter. In addition, the fact that the slat is then connected to the rocker arm 211 via the latch connection 217, 219 does not flutter when the rocker arm 211 is not rotationally stabilized by the then loose drive elements 213 when the slat 209 is not completely lowered.

As already mentioned, the described anti-rotation protection is particularly suitable for use together with the drive transmission described above, especially when the tilt drive elements for the blinds slats are mechanically rigidly connected to a blind drive.

Claims (18)

1. Stroke protection for slat blinds, with one carriage (5) that is motion-coupled with at least one of the slats for lifting and lowering movements, linearly along stationary frame parts (7, 7a) of the store, and at least one in the blind lifting level on the carriage (5 ) pivotable ratchet lever, which is locked by linearly moving the pivot point (19, 21) on the carriage (5) during the carriage stroke and finally coming into frictional contact with frame parts (7a), characterized in that the lever (15) is mounted on the carriage (5) in such a way, that the distance (r, r _b ) from the terminal end section (17) to the pivot point (19) of the lever (15) on the carriage (5) decreases when the lever pivot angle (ϕ) is approached by 90 ° with respect to the direction of stroke (H). 2. Lift safety device according to claim 1, characterized in that the lever (15) is mounted on the carriage (5) by means of a pin-groove connection (19, 21), the groove (21) being defined by a curve (m) , which is given with reference to the connecting part (17) by vectors, the amount of which decreases with increasing position angle (e) in the opposite stroke direction. 3. Stroke safety device according to claim 1, characterized in that on the carriage (5) a stop (25) for the lever (15) against further pivoting over a position of almost 90 ° with respect to the stroke direction (H) of the carriage (5) is provided. 4. Stroke safety device according to claim 1, wherein the lever between the bearing (19) on the carriage (5) and a docking section (17) with a stroke drive (11, 13) for the store can be coupled, characterized in that on the carriage (5) Stop (27) is provided, against which the lever (15) bears in this direction when taking up a swivel position of at least almost 90 ° with respect to the stroke direction (H), the coupling (13) of lever (15) and drive (11) lies between this stop (27) and the locking part (17), such that the lever (15) pivots about this stop (27) at least for the time being when it is swiveled out of the locking by means of the drive (11). 5. Lift safety device according to claims 2 and 4, characterized in that the curve (m) is designed at least in the region of the largest position angle with at least approximately one curvature (r) with the stop (27) as the center of curvature. 6. Lifting device according to claim 1, characterized in that the locking part is designed as an edge (17). 7. Drive transmission for lowering and lifting a slat blind, by means of a first belt-like element (37) and for tilting the slats by means of a second belt-like element (99), the first element (37) running on a drive element (35) that second is mounted on a driver assembly (81, 97) rotatably mounted for this purpose, characterized in that a controlled by the first element, drive member (35) and driver arrangement (81) either at least almost rigidly rotationally connecting or completely releasing coupling arrangement (41, 65, 81, 87) is provided. 8. Drive transmission according to claim 7, characterized in that the following are provided: a coupling element (41) which can be coupled to the first element (37) on the one hand by at least one driver (105), thereby on the other hand to a transmitter (65), at least one spring arrangement (87) which can be tensioned between the transmitter (65) and the driver arrangement (81, 97) by relative rotation of these parts, - A rotary stop arrangement (101, 103) which limits the rotational path of the driver arrangement (81, 97) with respect to a rotationally fixed housing section at least on one side; in such a way that the movement of the first element (37) after passing through a predetermined position, via driver (105), coupling element (41), transmitter (65), spring arrangement (87) onto the driver arrangement (81, 97) up to one the rotational stop arrangement (101, 103) transmits a fixed rotational position, after which the spring arrangement (87) resiliently opposes a relative rotation of the drive member (35) and driver arrangement (81, 97). 9. Drive transmission according to claim 8, characterized in that the coupling element (41) comprises at least one engaging member (61) mounted on the transmitter (65), which protrudes into the movement path of at least one driver (105) in the first element (37). 10. Drive transmission according to claim 8, characterized in that the coupling element on the transmitter (65) is displaceably, preferably spring-loaded (77), mounted and snaps in a predetermined position with the housing (31) and by the driver (105) from this position is movable. 11. Drive transmission according to claim 8, characterized in that the coupling element (41) comprises a radially guided, preferably spring-loaded slide on the transmitter (65), one with a corresponding molding or recess (63) on the housing (31) engaging in a predetermined rotational position Forming or shaping (57), the driver (105) in the rotational position acting tangentially at least approximately parallel to the slide guide (79) on the transmitter (65) on the slide (41). 12. Drive transmission according to claim 8, characterized in that the transmitter (65) comprises a cylinder sleeve located above a drive shaft for the organ (35), as well as the driver arrangement (83), a torsion spring (87) being provided in between as a spring element. 13. Drive transmission according to claim 8, characterized in that the spring constant of the spring element (87) is selected so that it acts as a practically rigid rotary connection until the rotary stop arrangement (101, 103) is reached. 14. Anti-twist device for slats of slat blinds, in which the slats (209) on the slat holders on the side can be lowered and raised, also tilted, and for the latter the holder is connected to a tilting arrangement (211), characterized in that the tilting arrangement (211) for the lamella (209) can be pivoted relative to the lamella holder (207) about the tilt axis, a release device (215, 217, 219) responding to a predetermined tilting moment being provided between the tilt arrangement (211) and the holder (207). 15. Tension prevention device according to claim 14, characterized in that the release device comprises a latching arrangement (217, 219) between the holder (207) and the tilting arrangement (211), e.g. a jack connection. 16. Anti-twist device according to claim 14, characterized in that the tilting arrangement (211) is spring-loaded (223) against a relative pivoting with respect to the lamella holder (207). 17. Anti-twist device according to claim 14, characterized in that the lamella holder (207) and the tilting arrangement (211) are braced against one another axially by a spring element (225). 18. Venetian blind with a lift safety device, according to at least one of claims 1 to 6 and / or a drive transmission according to at least one of claims 7 to 13 and / or a rotation protection device, according to at least one of claims 14 to 17, in particular with a drive transmission according to at least one of claims 7 to 13 and a anti-twist device according to at least one of claims 14 to 17.

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