EP0782833A1 - Drawing device for a curtain - Google Patents

Abstract

The curtain track has a number of running carriages (3,3'), supporting the upper edge of the curtain, which are freely movable along a horizontal rail (7), the carriage (3') supporting the curtain front edge driven by a flexible drive band (12), passed around pulleys at either end of the rail. One of these pulleys is rotated by an electric motor (9), via an intermediate drive (10), which is disengaged when a manual force is applied to the curtain and automatically re-engaged when the electric drive is operated.

Description

The invention relates to a so-called curtain train, i.e. a drive arrangement for an electrically operated curtain, the curtain of which is fastened at its upper edge to carriages which are supported on a horizontal, stationary running rail and are freely movable or movable on running rollers or slidably along the running rail , wherein a (first) carriage arranged in the region of a vertical curtain edge is designed as a towing carriage which is to be driven by a run of a self-contained, flexible drive belt which is arranged around two deflection disks which are arranged at one end of the running rail and engage the drive belt , Pulleys or the like. with vetical axis of rotation is, of which the deflecting pulley, which acts as a drive pulley, can be driven by an electric motor via a transmission, and the carriages are guided in the running rail between the two strands of the drive belt.

Such electric curtain pulls are used in particular in hotels to a greater extent in order to offer guests a high level of operating comfort, and it has been shown that the often relatively heavy curtains of motor-operated curtains are considerably protected compared to manual operation when opening and closing. However, they are also used in public and semi-public buildings and especially in larger windows in private households.

A disadvantage of the known electric curtain pulls is that the curtain cannot be opened or closed by hand in the event of a power failure or is extremely difficult to open by hand over the curtain (or an actuating rod connected to the towing vehicle) in the direction of the running rail Tractive force is exerted on the towing vehicle, since this is firmly connected to a run of the drive belt, and accordingly, to move the towing vehicle, the resistances of the drive (including its transmission) would have to be overcome, due to the existing gear ratios is generally not possible. Since the towing vehicle is practically blocked when the drive is at a standstill due to a power failure, appropriate attempts to open such a curtain by hand often result in the curtain tearing or other damage. Apart from that, it is also highly desirable to be able to open a curtain equipped with an electric curtain pull by hand in the event of a power failure, because at the same time the lighting will also fail, so that panic conditions can occur, especially in the unfamiliar environment of a hotel room. In particular, if a fire breaks out or if there are other dangerous conditions, it may be necessary to be able to rescue people through windows as freely as possible. But even under less critical circumstances, it is highly desirable to be able to open such a curtain by hand in the event of a power failure because, in general, not only in daylight with the curtain open does so much light fall into the room in question that an orientation of those in the room in question Person (s) is possible.

Furthermore, it may also be entirely desirable to be able to manually close a curtain, which can be driven by means of an electric curtain pull, in the event of a power failure, for example if one wants to go to rest during the day.

The present invention is based on the object of improving a curtain pull of the type described at the outset such that the curtain in question can also be opened and closed by hand effortlessly in the event of a power failure, and it should also be possible to actuate the curtain again by motor, when the power failure has ended without any installation measures being required.

The solution to this problem is, according to the invention, that the towing vehicle is connected to the drive belt via a coupling which is coupled in the normal operating state and which can be decoupled by a force which is exerted on the towing vehicle in the direction of the running rail and can be generated by hand via the curtain, so that the In the normal operating state, the towing vehicle connected to the drive belt, like the other carriages, can be moved freely in the running rail, and which engages automatically again from its uncoupled state when the drive belt is driven by the electric motor and is moved relative to the towing vehicle uncoupled from the drive belt.

Such a coupling between the towing vehicle and the drive belt can be designed in various ways. In a preferred embodiment it is provided according to the invention that the on the train car arranged one (first) coupling part has a coupling pin or pin which, in normal operating condition, engages with a free end section protruding laterally above the towing vehicle into a latching opening of the other (second) coupling part fastened to the inside of the drive belt, the coupling bolt by means of a spring is pressed into the latching opening and is movably mounted on the towing vehicle in the direction of its longitudinal axis against the restoring force of the spring, so that it can move out of the latching opening when uncoupling, and that the peripheral surface of the end section of the coupling bolt which engages in the latching opening or / and the side wall the detent opening forms an uncoupling ramp at an acute angle to the longitudinal axis of the coupling pin, the angle (s) and the elasticity of the spring being selected such that the coupling pin slides out of the detent opening against the restoring force of the spring when the towing vehicle - in al lgemeine on the curtain - is applied in the longitudinal direction of the running rail with manual force, but that the coupling bolt remains in the latching opening when the drive belt is driven by the electric motor. Such an angle and spring selection is empirically possible without further ado.

Such a mode of operation, in which the coupling bolt is coupled into the latching opening in the case of normal motor drive remains (and does not slide out of the locking opening via the decoupling ramp), while it is uncoupled from the locking opening (and does not remain in the locking opening) when the hand force is exerted on the towing vehicle in the direction of the running rail (and does not remain in the locking opening), is surprisingly in relatively wide ranges of Ramp helix angles and spring stiffness possible. This is based on the knowledge that the force to be transmitted by the clutch when the towing vehicle is driven via the drive belt is relatively small, since the resistance forces acting on the trolleys are very small, especially if the trolleys are provided with rollers while the resistances effective when the drive is stationary on the drive belt and thus on the second clutch part are already relatively large due to the transmission connected to the drive belt, so that the second clutch part having the latching opening is practically blocked or locked when a force is applied by hand when the drive is stationary is exercised on the train wagon.

The ramp angle (s) to be selected depends, among other things, on the frictional relationships between the coupling bolts and the side wall of the locking opening that engages with them, since the frictional force generated between the coupling bolts when the manual force is applied to the towing vehicle and thus to the coupling bolts and Side wall of the locking opening must be overcome to allow the coupling bolt to slide out of the locking opening. This would obviously not be possible if both the circumferential surface of the end section of the coupling pin engaging in the latching opening and the side wall of the latching opening run parallel to the longitudinal axis of the coupling pin, i.e. their angle to the longitudinal axis of the coupling pin is zero, and is also not possible if the angle is just a few degrees. On the other hand, however, this ramp angle must not be too large, because then there is a risk that the coupling pin will slide out of the latching opening even when the drive is from the electric motor via the drive belt, since then the coupling directed in the direction of the running rail is to be transmitted Driving force can be greater than the force required to disengage the clutch. It has been shown, however, that the ramp angle does not have to be empirically determined individually for each application, but that, under normal conditions, a ramp angle between 30 and 60 ° is suitable for ensuring the desired result, namely that the coupling bolt in the latching opening during normal engine operation remains while it slides out of the latching opening when the drive is at a standstill if the towing vehicle is subjected to manual force over the curtain in the longitudinal direction of the running rail.

Furthermore, it is preferably provided that the coupling pin is supported in its uncoupled state with a stop on the towing vehicle, which limits its axial movement generated by the spring so that the free end of the coupling pin is arranged at a distance from the drive belt in the uncoupled state, that is to say not with the latter can come into engagement so that the curtain can move freely after uncoupling.

In order to enable automatic recoupling after the end of a power failure, if the drive belt is to be driven by the electric motor again and the towing vehicle uncoupled relative to the drive belt is to be moved, it is preferably provided that the second coupling part which is fastened to the inside of the drive belt and has the latching opening its inside facing the coupling pin is provided with at least one guide ramp for guiding the coupling pin, which extends in the longitudinal direction of the running rail from the edge of the latching opening to one end of the second coupling part, the height of this guide ramp decreasing from the latching opening towards the end of the second coupling part and there is so high that the free end portion of the coupling bolt runs onto the guide ramp when the two coupling parts are moved towards each other. To allow the coupling pin can be engaged again from one or the other side of the latching opening, the second coupling part is preferably provided with two guide ramps running counter to the latching opening.

The drive belt is preferably provided in a manner known per se with through openings which are provided at the same mutual distance, so that deflection disks designed in the manner of chain wheels can engage with these deflection disks with their teeth, the second coupling part, which is preferably designed as a tab is provided on its outer side facing the drive belt with lugs which engage in a form-fitting manner in the passage openings of the drive belt in order to connect the second coupling part to the drive belt. Such a configuration can be used expediently at the same time to connect the mutually facing end sections of the drive belt to one another, i.e. to make the drive belt endless, if the second coupling part is arranged substantially centrally to the connection point of the drive belt, so that a separate connection is unnecessary .

Further preferred refinements of the present connection are described in the subclaims.

Fig. 1:

eine vereinfachte perspektivische Darstellung eines erfindungsgemäßen Elektro-Vorhangzuges, die insbesondere die zwischen dem Zugwagen und dem Antriebsband vorgesehene Kupplung zeigt, wobei diverse übrige Teile weggelassen bzw. gebrochen dargestellt sind, um die im entkuppelten Zustand dargestellte Kupplung verdeutlichen zu können;

Fig. 1a:

eine Darstellung gemäß Fig. 1, bei welcher ein Abschnitt des Behangs dargestellt ist, und außerdem Befestigungsmittel, mit denen die Laufschiene zu befestigen ist;

Fig. 2:

eine Darstellung gemäß Fig. 1 in verkleinertem Maßstab, welche die Kupplung während des Einkuppelvorgangs zeigt;

Fig. 3:

eine Darstellung gemäß Fig. 2, welche die Kupplung in eingekuppeltem Zustand zeigt;

Fig. 4:

eine schematisierte Schnittdarstellung durch den Zugwagen des Vorhangzuges gemäß den Figuren 1 - 3;

Fig. 5:

einen Schnitt durch die Darstellung gemäß Fig. 4 in Richtung der Schnittlinie V-V in Fig. 4 gesehen;

Fig. 6:

einen Schnitt durch die Darstellung gemäß Fig. 4 in Richtung der Schnittlinie VI-VI in Fig. 4 gesehen;

Fig. 7:

einen Schnitt durch die Darstellung gemäß Fig. 4 in Richtung der Schnittlinie VII-VII in Fig. 4 gesehen;

Fig. 8:

einen Schnitt durch die Darstellung gemäß Fig. 4 in Richtung der Schnittlinie VIII-VIII in Fig. 4 gesehen;

Fig. 9:

einen gegenüber den Figuren 1 - 8 vergrößerten, noch weiter vereinfachten Längsschnitt durch die Laufschiene und das Antriebsband im Bereich der Kupplung in deren ausgekuppelten Zustand;

Fig.10:

eine Darstellung gemäß Fig. 9 in eingekuppelten Zustand; und

Fig.11:

eine schematische Teildarstellung der Kupplung.

The invention is explained below using an exemplary embodiment with reference to a drawing. It shows:

Fig. 1:

a simplified perspective view of an electric curtain train according to the invention, which shows in particular the coupling provided between the towing vehicle and the drive belt, various other parts being omitted or broken in order to illustrate the coupling shown in the uncoupled state;

Fig. 1a:

a representation of Figure 1, in which a portion of the curtain is shown, and also fasteners with which the rail is to be fastened.

Fig. 2:

a representation of Figure 1 on a smaller scale, showing the clutch during the coupling process.

Fig. 3:

a representation of Figure 2, showing the clutch in the engaged state.

Fig. 4:

a schematic sectional view through the towing vehicle of the curtain train according to Figures 1-3;

Fig. 5:

seen a section through the illustration of FIG 4 in the direction of section line VV in Fig. 4.

Fig. 6:

a section through the representation of Figure 4 seen in the direction of section line VI-VI in Fig. 4.

Fig. 7:

seen a section through the representation of Figure 4 in the direction of section line VII-VII in Fig. 4.

Fig. 8:

seen a section through the representation of Figure 4 in the direction of section line VIII-VIII in Fig. 4.

Fig. 9:

an enlarged compared to Figures 1 - 8, further simplified longitudinal section through the running rail and the drive belt in the region of the clutch in its disengaged state;

Fig. 10:

a representation of FIG 9 in the engaged state. and

Fig. 11:

a schematic partial representation of the clutch.

FIG. 1 shows the parts of a curtain train, which are essential for the explanation of the present invention, indicated with 1, various parts being omitted or broken away in order to better illustrate the present invention. The curtain pull 1 is an essential part of a curtain, the curtain 2 of which is also omitted in FIG. 1, but is indicated in the detail in FIGS. 1 a, 2 and 3. Fig. La also shows fasteners 27 with which the curtain 1 e.g. to be fastened to a lintel or the ceiling of a room.

The curtain 2 is attached at its upper edge 2 'to a plurality of carriages 3, specifically with latching hooks 4, which are each to be snapped into an eyelet 5 (see FIG. 6). The carriages 3 are provided with rollers 6 which are supported on a horizontal, stationary running rail 7 (see FIG. 6). They can be moved freely along the running rail 7.

The first carriage arranged in the region of a vertical curtain edge 8 is designed as a towing carriage 3 'and differs from the other carriages 3 essentially in that it can be driven by the drive described below, while the other carriages 3 do not directly but only via this the curtain 2 are connected.

The drive consists of an electric motor 9, indicated by dash-dotted lines in FIG. 1, which is connected to a transmission 10. The gear 10 acts on a drive disc in the gear housing, which is arranged as a chain wheel and has a vertical axis of rotation in the gear housing in FIG. 1, the teeth of which engage in recesses 11 of a self-contained, flexible drive belt 12, which at the other end of the guide rail 7 is deflected by a deflection disk, also designed as a chain wheel, with a vertical axis of rotation.

Since the structure of the curtain pull 1 described so far is known to the person skilled in the art, a graphic representation of the drive or deflection disks, the gear, etc. has been dispensed with. In this respect, it should only be noted that the operation takes place in the normal operating state so that the reversible electric motor 9 is driven in its one direction of rotation when actuated by a switch, not shown, and drives the drive belt 12 via the gear and the drive pulley, so that its two strands 12 'and 12 "move in the opposite direction in the running rail 7, the towing vehicle 3' being connected to the run 12 'of the drive belt 12 (see FIG. 3), so that the curtain 2, for example, from its open position to its closed position is moved by first moving the towing vehicle 3 'connected to the drive belt 12 and thereby takes the carriage 3 following it with it when the curtain 2 is stretched between the latter and the towing car 3 ', etc. The curtain 2 is closed by actuating the electric motor 9 in the reverse direction of rotation, again in turn only the one connected to the drive belt 12 Train carriage 3 'is driven until it runs against the carriage 3 adjacent to it and takes it along, etc. At this point, it should again be expressly pointed out that the other carriages 3 adjacent to the carriage 3' are omitted in the drawing.

In contrast to known generic curtain trains, in which the towing vehicle 3 'is hooked into recesses 11 of the drive belt 12 or is permanently permanently connected in some other way to the drive belt 12, in the present curtain train 1 between the towing car 3' and the drive belt 12 (more precisely said whose run 12 ') a coupling consisting of two coupling parts or halves 13 and 14 is provided, which is coupled in the normal operating state (see FIGS. 3, 8, 10) and is designed such that it remains coupled when the drive belt 12 is driven by the electric motor 9, but can be disengaged if a force is exerted on the towing vehicle 3 'via the curtain 2 in the direction of the running rail 7 by hand on the towing vehicle 3', this coupling 13, 14 in FIG uncoupled state is shown.

For this purpose, the first coupling part 13 arranged on the towing vehicle 3 'has a coupling bolt 15 projecting laterally over the towing vehicle 3' in the direction of the run 12 'of the drive belt 12, which in the coupled, normal operating state with its free end section 15' into a latching opening 16 of the second coupling part 14 fastened on the inside of the drive belt 12 engages, namely the coupling pin 15 is pressed into the latching opening 16 by means of a compression spring 17 surrounding it concentrically. The coupling pin 15 is movably mounted on the towing vehicle 3 'in the direction of its longitudinal axis 19 against the restoring force of the spring 17.

As can be seen in particular from FIGS. 9-11, the peripheral surface 18 of the free end section 15 'of the coupling bolt 15 extends at an acute angle α to the longitudinal axis 19 of the coupling bolt 15, which in the exemplary embodiment shown is 40 °. The side wall 16 'of the latching opening to the longitudinal axis 19 also extends at this angle α. However, it could also run at a different angle and possibly even parallel to the longitudinal axis 19, as is indicated in FIG. 11 by dash-dotted lines.

As can be seen from FIGS. 1 and 9, the coupling pin lies 15 in its uncoupled state with a stop 20 on a side wall of the towing vehicle 3 ', the stop 20 limiting the axial movement of the coupling bolt under the action of the spring 17 such that the free end 15' of the coupling bolt 15 in the uncoupled state at a distance from the run 12 'of the drive belt 12 is arranged, that is, there is no connection between the towing vehicle 3' and the drive belt 12. The stop 20 is designed as a flange, on the side opposite the stop side of which is supported the spring spring 17, designed as a helical spring, which is supported at its other end on the opposite side wall of the towing vehicle 3 '.

The second coupling part 14 fastened to the inside of the run 12 'of the drive belt 12 is designed as a lug-shaped molded plastic part and has on its inside facing the coupling pin 15 two guide ramps 21 and 21' running in opposite directions to the latching opening 16 for guiding the coupling pin 15 in the longitudinal direction of the running rail 7 and each extend from the edge of the latching opening 16 to the end of the second coupling part 14, the height of the guide ramps 21, 21 'decreasing from the latching opening 16 to the respective end of the second coupling part 14 and being so high there, that the free end portion 15 'of the coupling pin 15th runs onto the relevant guide ramp 21 or 21 'when the two coupling halves 13 and 14 are moved relatively towards one another, as will be explained further below.

The second coupling part 14 is provided on its outer side facing the drive belt 12 with lugs 22 which engage in a form-fitting manner in through openings 11 of the drive belt 12. Since the second coupling part 14 is arranged centrally to the two mutually facing end sections of the drive belt 12, this can be made endless by means of the second coupling part 14 without further measures being required for this.

The diameter D of the coupling pin is 3 mm. In the coupled state, it engages only slightly in the latching opening 16.

For a better understanding of the embodiment shown in the drawing, it should also be pointed out that the towing vehicle 3 'consists of two blocks, each similar to a carriage 3, which are firmly connected to one another via a bracket 23. This measure, which can be seen in particular from Fig. 4, is provided to the to be able to fasten the bracket 23, which functions as an overflow bracket, in a simple and stable manner, which is bent away from the running rail in order to be able to run over a vertical edge section of a second curtain when the curtain is closed.

5 seen in the direction of the section line V-V shows the profile of the running rail 7 and thereby recognize that the strands 12 'and 12' 'of the drive belt 12 run on the side walls of the running rail 7.

The sectional view according to FIG. 6 shows that the carriages 3 are guided in the running rail 7 between the two runs 12 ′, 12 ″ of the drive belt 12, the carriage 3 recognizable in FIG. 6 being omitted in FIG. 4, however.

The sectional view according to FIG. 7 shows a sectional view in the area of the towing vehicle 3, and FIG. 8 shows a sectional view in the area of the first coupling part 13 or the coupling pin 15.

In the normal operating state (see FIGS. 3, 8, 10), the free end section 15 'of the coupling bolt 15 is latched into the latching opening 16 of the second coupling part 14, so that the two coupling parts 13,14 are engaged. If the electric motor 9 is actuated, it drives the curtain 2 via the gear 10, the drive pulley, the run 12 'of the drive belt 12, the coupling 13, 14 and the towing vehicle 3' either in the opening or in the closing direction. There is no uncoupling because the coupling pin 15 is pressed axially into the latching opening 16 by means of a force F (see FIG. 11) and the driving force A thereby generated, which is between the side wall 16 'of the latching opening 16 and the peripheral surface 18 of the conical free End portion 15 'of the coupling pin 15 is transmitted, is not sufficient to allow the coupling pin 15 to slide out of the locking opening 16. This is based on the fact that the forces generated by the curtain 2 or the carriage 3, during the movement of which the resistance forces to be overcome are extremely low due to the rolling friction between the carriage 3 and the running rail 7.

If there is a power failure, however, so that the electric motor 9 cannot be actuated, and a manual force H is exerted on the towing vehicle 3 'and thus the coupling bolt 15 against the then practically blocked second coupling part 14 in the direction of the running rail 7 by - is pulled on the curtain in one direction or the other - in the direction of the running rail 7, so that the peripheral surface 18 of the free end section is pressed against it 15 'of the coupling pin 15 to the side wall 16' of the latching opening 16, the coupling pin 15 sliding out of the latching opening 16 in the direction of arrow 24 (see FIG. 11) when the force component caused in this direction by the manual force H is greater than the frictional force generated in the case of the mutual contact pressure acting in the opposite direction of the arrow 24. Since this depends not only on the coefficient of friction and thus on the materials and the surface properties of the abutting surfaces 18, 16 'of the coupling bolt 15 or the second coupling part 14, but is also proportional to the normal force acting between these two surfaces 18, 16' and this is also determined by the spring force F of the spring 17, there is evidently the possibility during assembly of the curtain to influence the frictional relationships between the coupling pin 15 and the latching opening 16 by choosing a weaker or stronger spring 17 or changing the spring preload. However, it has been shown that this is not necessary under normal conditions, since the decoupling force that can be achieved by an easily generated hand force H at ramp angles α by 45 ° is easily sufficient to overcome the friction and still cause the clutch 13, 14 remains engaged when the drive from the electric motor 9 takes place via the drive belt 12. As already mentioned, this is based, among other things, on that a force that can be applied by hand over the curtain 2 to the towing vehicle 3 'in its longitudinal direction is advantageously considerably greater than the resistance forces generated or effective by the trolleys (even in the final phase of the opening or closing process, if all carriages are moved), and that the force to be transmitted by the clutch 13, 14 during normal engine operation does not exceed these resistive forces, so that - expediently by means of appropriate experiments - a design can be found relatively empirically by means of which the hand force required for uncoupling lies between the maximum hand force that can be applied and the maximum driving force required for such curtains, so that the curtain pull 1 or its coupling 13, 14 is suitable for a large number of applications or even for all occurring applications.

As soon as the coupling pin 15 has slipped out of the latching opening 16, its free end reaches the guide ramp 21 (see FIG. 2) or 21 'and slides along the curtain 2 when it is pulled further under the action of the spring 17 until it moves away from it second coupling part 14 is free. This position is shown in Figures 1 and 9. The curtain can then be easily opened or closed completely by hand, since now the Train carriage 3 'has become a "normal" carriage 3, which is no longer connected to the drive belt 12.

If, after the power failure has ended, the electric motor 9 is switched on in such a way that the second coupling part 14 fastened to the drive belt 12 moves towards the towing vehicle 3 ', the coupling 13, 14 is automatically engaged again. If the second coupling part 14 runs in the direction of arrow 25 (see FIG. 9) towards the towing vehicle 3 ', the guide ramp 21 runs onto the free end section 15' of the coupling bolt 15 and pushes it progressively in the direction of its longitudinal axis 19 against the spring 17 in the towing vehicle 3 'until the catch opening 16 is reached and the coupling bolt 15 engages in the catch opening 16. The same happens automatically when the towing vehicle 3 'is located on the other side of the second coupling part 14 and this is driven in the opposite direction via the drive belt 12.

Due to the design according to the invention, it is now possible to open or close the curtain of a curtain provided with an electric curtain pull easily and without risk of damage even in the event of a power failure, the curtain again in itself after the power failure has ended The intended way can be operated via its electric drive, since the clutch, which was still uncoupled, automatically engages again and remains engaged during further operation until a force is exerted on the towing vehicle by hand in the event of a renewed power failure, which disengages the clutch 13 , 14 leads.

Reference list

1

Curtain train

2nd

Curtain

2 '

top margin (of 2)

3rd

Carriage

3 '

Train carriage

4th

Locking hook

5

eyelet

6

Casters

7

Track

8th

(vertical) curtain edge

9

Electric motor

10th

transmission

11

Recesses (of 12)

12th

Drive belt

12 '

Run (out of 12)

12 ''

Run (out of 12)

13

first coupling part

14

second coupling part

15

Coupling bolt

15 '

free end section (of 15)

16

Rest opening

16 '

Side wall (of 16)

17th

feather

18th

Circumferential surface (from 15 ')

19th

Longitudinal axis (from 15)

20th

attack

21.21 '

Guide ramps (of 14)

22

Approaches (of 14)

23

hanger

24th

arrow

25th

arrow

Claims (12)

Curtain train (1) for a curtain that can be actuated by an electric motor, the curtain (2) of which is attached at its upper edge (2 ') to carriages (3,3') which are supported on a horizontal, stationary running rail (7) and along the running rail ( 7) can be moved freely, whereby a (first) carriage (3 ') arranged in the area of a vertical curtain edge (8) acts as a towing carriage (3'), which is run from a strand (12 ') of a self-contained, flexible drive belt (12 ) to be driven, which is arranged around two at one end of the running rail (7) and engages with the drive belt (12) standing deflection disks or the like. is guided with a vertical axis of rotation, of which one deflecting disc can be driven by an electric motor (9) via a gear (10), and the carriage (3, 3 ') between the two runs (12', 12 '') of the drive belt (12) are guided in the running rail (7), characterized in that the towing carriage (3 ') is connected to the drive belt (12) via a coupling (13, 14) which is coupled in the normal operating state and which is connected in the direction of the running rail (7) on the towing vehicle (3 '), which can be generated via the curtain by hand, and which automatically disengages from its uncoupled state when the drive belt (12) is driven by the electric motor (9). Curtain pull according to Claim 1, characterized in that the one (first) coupling part (13) arranged on the pulling carriage (3 ') has a coupling bolt (15) which, in the normal operating state, has a free end section projecting laterally over the pulling carriage (3') ( 15 ') engages in a latching opening (16) of the other (second) coupling part (14) fastened to the inside of the drive belt (12); that the coupling pin (15) is pressed into the latching opening (16) by means of a spring (17) and is movably mounted on the towing vehicle (3 ') in the direction of its longitudinal axis (19) against the restoring force of the spring (17); and that the peripheral surface (18) of the end section engaging in the latching opening (16) (15 ') of the coupling bolt (15) and / or the side wall (16') of the latching opening (16), forming an uncoupling ramp at an acute angle (α) to the longitudinal axis (19) of the coupling bolt (15), the (the ) Angle (α) and the elasticity of the spring (17) are chosen so that the coupling pin (15) slides against the restoring force of the spring (17) from the latching opening (16) when the towing vehicle (3 ') in the longitudinal direction of the running rail (7) is subjected to manual force, and that the coupling bolt (15) remains in the latching opening (16) when the drive belt (12) is driven by the electric motor (9). Curtain pull according to claim 2, characterized in that the angle (α) between the peripheral surface (18) of the free end portion (15 ') of the coupling bolt (15) and its longitudinal axis (19) is approximately 30-60 °. Curtain pull according to claim 2 or 3, characterized in that the coupling bolt (15) in its uncoupled state is supported by a stop (20) on the towing carriage (3 '), which limits its axial movement so that the free end of the coupling bolt (15) is arranged at a distance from the drive belt (12). Curtain pull according to one or more of claims 2-4, characterized characterized in that the second coupling part (14) fastened to the inside of the drive belt (12) is provided on its inside facing the coupling pin (15) with at least one guide ramp (21, 21 ') for guiding the coupling pin (15) which is in The longitudinal direction of the running rail (7) extends from the edge of the latching opening (16) to one end of the second coupling part (14), the height of the guide ramp (21, 21 ') from the latching opening (16) to the end of the second coupling part (14) decreases and there is so high that the free end portion (15 ') of the coupling bolt (15) runs onto the guide ramp (21 or 21') when the two coupling parts (13, 14) are moved towards one another. Curtain pull according to claim 5, characterized in that the second coupling part (14) is provided with two guide ramps (21, 21 ') running counter to the latching opening (16). Curtain pull according to claim 5 or 6, characterized in that the second coupling part (14) is designed as a tab. Curtain train, the drive belt of which is provided with through openings into which the deflection disks designed in the manner of chain wheels engage, characterized in that the second Coupling part (14) on its outside facing the drive belt (12) is provided with lugs (22) which engage in a form-fitting manner in through-openings (11) of the drive belt (12). Curtain pull according to claim 8, characterized in that the second coupling part (14) is arranged substantially centrally to the connection point of the drive belt (12) and connects the mutually facing end sections of the drive belt (12). Curtain pull according to claim 4, characterized in that the stop (20) is designed as a flange, on the side opposite the stop side of which is supported the spring (17) designed as a pre-tensioned coil spring, which is arranged concentrically with the coupling bolt (15) and with its other end is supported on the towing vehicle (3 '). Curtain pull according to one or more of the preceding claims, characterized in that the coupling bolt (15) has a diameter of approximately 2 mm. Curtain pull according to claim 11, characterized in that the coupling bolt (15) engages approximately 1-2 mm into the latching opening (16) in the coupled state.

Images