EP2596191B1 - Damping unit for discontinuously damping a rotational motion - Google Patents

Description

The present invention relates to a damping unit for discontinuous damping of a rotational movement of a drive shaft rotatable about a drive wheel, in particular a drive wheel of access barrier, by means of a discontinuous transmission, which is composed of two meshing, eccentrically mounted, non-circular gears and the drive wheel with a output shaft associated attenuator connects.

Such a damping unit is already in the German patent application DE 36 38 353 A1 previously known. There, a continuous rotation of the end of a knee joint connected to a door closer is converted by means of a gear consisting of two identical non-circular gears into a discontinuous rotation, which is finally subjected to a damping.

In such door closers, but also in particular in access barriers used in person singling facilities, access to a protected area is usually made conditional on, for example, the presence of a valid ticket. Therefore, such a lock will lock after every passage of a person, so that with a valid ticket not more people can enter the protected area. By this locking a mechanical blockade of the access barrier is triggered, which prevents further rotation. Would the access barrier with undiminished speed moves to the end position, so would the snapping the locking mechanism on the one hand stress the material and on the other hand mean a noise pollution. Such noise in the area of access barriers is usually perceived as a negative quality feature, so that there is a need on the part of the manufacturer to avoid this.

Basically, it is therefore desirable in such attenuations, be it in access barriers, door closers or other comparable facilities to dampen the movement of the access barrier in the end position so that a gentle but rapid Endlagenlauf is achieved. A continuous rotational movement could only take place evenly in a direct damping, so that the door would only be sluggish due to the damping, at best in the area of the extreme points of the Dämpferkolbenauslenkung would run easier. Because the damping effect is dependent on the rotational speed, wherein a high rotational speed means high damping, a low rotational speed means low damping, an increasing rotational speed must be achieved for damping in the region of the end positions. This can be achieved by the use of a discontinuous gear, which is designed so that an increasing rotational speed of the crank after the unstable position takes place until shortly before the end position.

The well-known from the above-mentioned published patent cogs, which are identical, have in the implementation of the continuous in a discontinuous rotary motion, however, the disadvantage that due to the identical design of the gears a significant deviation from the ideal damping curves must be taken into account.

The prior art therefore uses other ways of producing a damping process that is as ideal as possible. From the German patent DE 10 2007 010 385 B4 For this purpose, for example, a locking unit for a turnstile system is known. Such a turnstile system represents a possibility of an access barrier in which a blocking element is provided, which provides a spatial subdivision. By a stepping step of the blocking element, a passage through the access barrier by one person is possible, whereby a person separation is realized. In the context of the disclosure of this German patent advancing the locking element is realized by a motor which is controlled so that in the end region of the movement, ie in the region of the end position of the locking element, a damping is provided. This damping is realized by slowing down the engine in the area of the end position so that it does not swing beyond the end position.

For various reasons, whether for reasons of noise reduction, explosion protection or because customers expect a mechanical solution a longer service life than electronic components, there is also a demand for purely mechanical access barriers, which then have a qualitatively good attenuation should. This is - as in the motorized variant - an increasing damping to be achieved until shortly before reaching the end position, ideally a structurally identical as possible product variant as in the motorized case is desired to allow a conversion or a leaner production.

The present invention is therefore based on the object to provide a damping unit for continuously reinforcing end position damping of a rotational movement, which allows the best possible damping curve without overshooting and at the same time waives the use of an engine.

This object is achieved by the damping unit according to the features of claim 1. Further useful embodiments of the damping unit can be taken from the dependent claims.

Structurally, first a drive wheel is present, to which the access barrier attaches with its force. With the drive wheel, which is rotatably mounted about a drive axis, the torque of the movement of the access barrier is transmitted to the damping unit. Instead of providing a motor for this, a black box was first provided here, which should unfold the same mode of action, as a motor in the control described above. It has been found to be an inventive solution to provide for the black box a discontinuous transmission, which converts the generated by the rotation of the person passing through continuous rotation of the access barrier or the drive wheel of the access barrier in a discontinuous rotation. As a result, due to the continuous rotation of a drive axle of the discontinuous gear used, an incessant movement of an output shaft of the same discontinuous gear is produced, whereby a speed-dependent damping on the output shaft now causes a strong damping at high speeds of the output shaft, while a low speed of the output shaft Damping brings with it. The discontinuous gear used for this purpose comprises two non-circular gears, which have different Wälzkurven. It has been found that the gear arranged on the drive axis can preferably have a substantially egg-shaped pitch curve, while the other non-circular gear which is seated on the output shaft is shortened in the direction of the extremity relative to the drive-side gear, but widened transversely thereto. Such a distribution of the Wälzkurven generated in particular compared to the use of identical, for example egg-shaped, Wälzkurven a much more progressive speed curve on the output shaft as a system response to the application of a continuous rotation on the drive axle. This results in a cleaner end-run and a more uniform damping behavior during the rotation, resulting in an independence of the passage speed, in each case a controlled Endlagenlauf takes place.

A less preferred, in particular in the end-of-run and in the unstable position worse configuration arises by interchanging the two gears, so arranging the widened and shortened gear on the drive axle. However, protection is explicitly sought for this.

Both non-circular gears are each designed symmetrically, so that rotation of the access barrier can be done in both directions. Here is the zero point, as well as a labile balance in the middle rotational position in a position of the gears in which their axes of symmetry are congruent. The

Gears have equal numbers of teeth to allow multiple passages in the same direction.

An advantage of the identical rolling curves according to the prior art is that only one tool has to be produced for the production of the identical gears. Due to the cost of such tools, this represents a decisive advantage, which makes a poorer rotational behavior quite acceptable. However, the invention uses MIM or CIM parts to minimize the cost of the tool. The cost of the tools required thereby are many times lower than the cost conventionally required for such metallic gears tools.

An attenuation of the output shaft can be done according to the invention either by a turn there provided motor, which in a similar manner, as described above, is controlled. As far as the known from the prior art discontinuous transmission is used with two identical gears, the use of a motor for driving the transmission from the actual output side will lead to an identical curve of the speed, which means that a constant rotation of the motor Rotation of the revolving door has the consequence, which is very fast in the area of unstable central position. The motor would have to be elaborately controlled in such a way that its movement takes place in accordance with the function with constant rotation on the drive side. In addition, the engine would have to be much stronger than standard. The transmission according to the invention, however, is designed by its shape so that the inverse function is a sine or cosine, so that automatically at the speed of the engine speed of the up and down realized, so a maximum speed at the apex of the movement is achieved. The damping unit according to the invention is therefore suitable and designed both for the motor drive by a constantly rotating motor as well as for manual operation, wherein in the case of engine operation, the functions of the drive and driven axles are reversed. The motor thus acts on the output shaft and causes via the discontinuous gear rotation of the access barrier. The inventive design of the transmission here ensures that the behavior of the transmission in both operating directions is exactly the same, so that when applying a constant motor speed on the output shaft, the inverse function on the drive axle is a sine or cosine. Thus, due to the also lower required force for acceleration and deceleration, smaller engines can be used which reduce costs compared to more powerful engines.

The determination of an ideal damping function can be carried out on the basis of a gear coupling mechanism by determining the ideal breakaway torque in the stable position, that is to say the so-called holding torque, by changing the crank distance in the gear coupling gear. From the integrated crank in the gear coupling can be read as inverse a sine or cosine function, which brings the above-mentioned advantages for motorized operation. The determined function and the inverse function is now transferred to two non-circular gears, since the assembly of a gear coupling with respect to the use of the inventive discontinuous transmission with two gears is much more difficult and therefore more expensive.

In a further embodiment, it is provided to associate the output shaft with a crank element, so that an eccentric connection of the damping element designed, for example, as a spring-damper element to the output shaft is made possible. Such an attenuator can for example be advantageously integrated into a gas spring which comprises a piston and a cylinder. In a linear movement of the piston in the cylinder or out of the cylinder, the movement in question is damped, so that by connecting this piston in an eccentric manner with the output shaft, for example via said crank element, but optionally also directly with parts of the discontinuous transmission, the desired damping is provided.

To further avoid overshooting in the end position, it is provided that the end position of the drive wheel is reached where the discontinuous transmission and the spring element are in a stable equilibrium. This means that the discontinuous gear is in the range of the fastest movement of the output shaft, while the piston is in its potential-free position. Incidentally, it is provided that the piston dampens only in one direction, in particular in the extension direction, so that in the opposite direction, that is to say in particular during insertion, an undamped movement is possible. For this purpose, for example, the piston of the gas spring on a corresponding valve, via which oil flows over the valve opening of the piston and thus does not take place damping in the direction mentioned.

However, it is also readily possible to turn the direction of effect to the effect that the gas spring damps only in the slot, which should be expressly covered by the invention. Damping is also possible in both the inlet and the outlet, although not the preferred variant.

A ausgestaltetes example, in the form of a return spring, additional return element can be used to spend the access barrier from a labile position, for example, if they leave after the start of a rotation back in the opposite direction, back to an end position. For this purpose, a provision is always placed in the nearest end position so as not to cause undesirable completion of the rotation when the rotation begun is discontinued.

In order to obtain the greatest possible freedom in the application of such a damping unit, it is provided to provide a crank instead of a simple crank on the output shaft of the discontinuous transmission, which only allows an eccentric connection with the attenuator to use a crank disc which is distributed over its circumference Fixing means for the attenuator provides, which have different eccentricities. If a toothed shaft is used as the drive axle and / or driven axle, the fastening means are distributed in the same number around the pivot point as teeth are provided on the toothed shaft. This allows the crank disc to assign each position of the fastener in a suitable manner. This makes it possible to set the degree of damping again, especially in different sized access barriers with different mass to adjust the degree of attenuation in detail. In addition to the possibility of a fine adjustment, this also provides a way to make an adjustment to various products, such as turnstiles, revolving doors with different pitches, etc.

A further additional damping can be achieved in that the discontinuous transmission is accommodated in a housing which is filled with transmission oil. As a result, a smoother running of the discontinuous transmission is ensured, which is a damping measure, which has an even effect on the entire, continuous rotation of the drive wheel.

Another integration step is effected by the fact that the drive axle, which is operatively connected to the drive wheel, and the output shaft, on which the damping acts, are each made in one piece with the associated non-circular gear. Together with the ball bearings used, which store the non-circular wheels together with axles in the two-shell housing provided for this purpose, not more than eight parts are required for the complete non-circular gear. The assembly of such a non-circular gear turns out to be extremely simple and very inexpensive.

As already shown above, such a damping unit should be used for a number of products, especially for revolving doors and turnstiles of different pitch. In a 90 ° division of the hub, the drive wheel in the direction of the access barrier requires a 1: 4 ratio, so that a quarter turn of the hub causes a single, complete revolution of the drive axle and the output shaft.

The drive shaft also performs a complete rotation, so that due to the discontinuous transmission, first a fast movement and then a slow motion range, then again a rapid movement follow one another. Thus, there are two areas of fast movement, it being noted that the attenuation of the attenuator is stronger during rapid movement, so that in a conventional damping cylinder actually these two areas would be greatly attenuated. However, as a result of the fact that the damping member only acts in one direction, appreciable damping takes place only in the case of the last-mentioned rapid movement, this range being in the region of the end position of the turnstile. Due to the spring pressure of the attenuator here sets a stable end position run. By another translation, the same unit for a 120 ° division or 180 ° division can be used, if then a 1: 3 or a 1: 2 translation is provided.

Since the discontinuous transmission will usually be enclosed in a housing and an alignment of the discontinuous transmission will be required to place the moment of greatest damping in the end region of the movement, it seems expedient to take measures to ensure the correct position of the discontinuous transmission in to ensure the housing. For this purpose, the drive axle or the output shaft may be at least partially formed as a toothed shaft, so that directly on this toothed shaft in the case of the output shaft, the crank element and in the case of the drive axle, the translation or the drive wheel can be placed. It is particularly useful if translation or drive gear have a multiple of the teeth, as provided in the toothed shaft. In this case it is ensured that with each position of the translation wheel or the drive wheel, a correct setting is possible.

In addition, however, it is provided that a mark for the correct position of the discontinuous transmission is attached to the toothed shaft.

An alternative embodiment of the damping unit, according to which the drive wheel is designed as a toothed wheel, which engages in a rack or a toothed belt, allows use as a damping unit for a sliding door, when the rack or the toothed belt is arranged in the region of the wall and the gear Drive wheel turns. The drive wheel may, if necessary, be stunted so that a complete postponement of a complete revolution corresponds to the drive axle, ideally a not quite complete rotation is anzupeilen so that the rest position is ideally achieved in a maximum damping and thereby in a torque maximum and the door closes safely , If you push the door slightly over the middle position to the open or the closed position, it then moves automatically, pushed by the spring force of the spring-damper element, in the respective open or closed position.

The same applies to the case of an insert of the damping unit in question for a swinging door, in which case a toothed rail is arranged in the opening direction of the door, which engages in the drive wheel or a gear associated therewith. If necessary, a translation can also be used here.

The invention described above will be explained in more detail below with reference to an embodiment.

Fig. 1:

ein Dämpfungsaggregat gemäß dem Stand der Technik in einer perspektivischen Darstellung von schräg oben,

Fig. 2:

ein erfindungsgemäßes Dämpfungsaggregat in einer perspektivischen Darstellung von schräg oben,

Fig. 3:

ein Diagramm verschiedener Kolbenabtriebsgeschwindigkeiten gemäß dem Stand der Technik, der Erfindung und dem Idealfall,

Fig. 4

ein Diagramm, welches die Inversfunktion der Funktion gemäß Fig. 3 gemäß der Erfindung zeigt,

Fig. 5:

eine Drehtür mit einem Dämpfungsaggregat gemäß Fig. 2 in einer perspektivischen Darstellung,

Fig. 6:

eine Schwingtür mit einem Dämpfungsaggregat gemäß Fig. 1 in einer perspektivischen Darstellung, und

Fig. 7:

eine Schiebetür mit einem Dämpfungsaggregat gemäß Fig. 1 in einer perspektivischen Darstellung.

Show it:

Fig. 1:

a damping unit according to the prior art in a perspective view obliquely from above,

Fig. 2:

an inventive damping unit in a perspective view obliquely from above,

3:

a diagram of different piston output speeds according to the prior art, the invention and the ideal case,

Fig. 4

a diagram showing the inverse function of the function according to Fig. 3 according to the invention,

Fig. 5:

a revolving door with a damping unit according to Fig. 2 in a perspective view,

Fig. 6:

a swinging door with a damping unit according to Fig. 1 in a perspective view, and

Fig. 7:

a sliding door with a damping unit according to Fig. 1 in a perspective view.

FIG. 1 shows a damping unit 10 according to the prior art, which is particularly suitable for damping a rotational movement of an access barrier. The rotational movement of the access barrier in this case acts on a translation not shown, wherein the rotational movement is transmitted to the drive wheel 13. The drive wheel 13 is mounted on a drive axle 15, which is connected to a discontinuous transmission consisting of two identical non-circular gears 11 and 12. Due to the egg-shaped Wälzkurve the gears 11 and 12 is a continuous rotational movement of the access barrier in a discontinuous rotational movement on a driven shaft 16, which is connected to a damping element 17, 18, converted. Due to the identical Wälzkurve it is not necessary to produce several tools for the two gears 11, 12, so that the costs incurred for the production of the gears 11, 12 costs are kept low. However, the resulting Wälzkurve is not ideal because it favors intermediate damper and muffled in the range of the final position inaccurate. Also the area of the unstable situation is very pronounced.

FIG. 2 shows the solution according to the invention, which is constructed substantially the same, but has two gears 11 and 12 with different Wälzkurven. Thus, the Wälzkurve a drive-side gear 11 is substantially egg-shaped, while the Wälzkurve the driven-side gear 12 relative to the pitch curve of the drive-side gear 11 is shortened in the direction of eccentricity, but widened in the transverse direction. As a result, both gears 11, 12 have the same circumference and allow an idealized course of the rotational speed generated on the output shaft 16 and thus the damping.

This is done via a force acting on the output shaft 16 piston 18 of a gas spring 17, which is connected via a crank member 14 with the output shaft 16. As a result, the discontinuous rotational movement is converted to a linear movement, which is damped by the gas spring 17. The gas spring 17 dampens only in the extension of the piston 18, so that at a full rotation of the output shaft 16, the gas spring 17 only in the second half, so after a complete insertion of the piston 18 in the cylinder of the gas spring 17, begins with the damping. Starting from the end position shown, therefore, a rotation of the access barrier connected to the drive wheel 13 will be undamped until the end of half a turn, then the damping will begin. However, the damping acts as a function of the Ausschubgeschwindigkeit of the piston 18, so that due to the discontinuous motion, the damping due to the kinematic design of the discontinuous transmission from the second half to almost the end of the rotation, increasingly dominant acts on the overall system, so that in End sufficiently strong damping takes place in order to prevent the access barrier from overshooting and to make them come to a standstill in the range of their final position.

FIG. 3 shows a diagram in which the curves of the piston speed is plotted against the rotation angle of the driven side gear 12, according to an Idealverlauf 51, a course according to the solution of the prior art 50 and according to the invention 52. In view of the symmetry of the two gears 11, 12 acts It also in the curves 50, 51 and 52 symmetric curves whose symmetry represents a point symmetry around the zero point in the rotation of π . The ideal curve 51 shows in the area around the point of symmetry 53 a steep and substantially constant slope, which means a uniform damping in this area. At this point of symmetry 53, the system achieves a labile equilibrium in which the piston speed has a turning point. Due to the high speed change is avoided that the access barrier can remain in its center position for reasons of friction. The same applies to the curve with gears according to the invention 52. Only the curve with the same gears 50, which reflects the prior art, has too low a speed change of the piston in the slope, which mean intermediate decelerations and accelerations, due to the damping behavior of the piston Lead 18 to intermediate dampers in the move. Also, the high point of the damping or the piston speed is shifted in the case of the curve with gears according to the invention 52 further in the direction of the end position than in the curve with the same gears 50, resulting in a cleaner Endlagenlauf.

If the person passing the access barrier does not drive the transmission but a motor mounted on the output side, then the transmission according to the invention provides for an inverse curve 54 FIG. 4 which results on the drive side or on the side of the access barrier to a sine or cosine curve. The interpretation thus allows the use of the same transmission for manual operation and motorized operation, in the latter case, the engine does not have to be subjected to a complex control process, but can be driven at a constant speed to a suitable movement of the access barrier, ie a clean high and runoff, to ensure.

The arrangement according to FIG. 5 shows a damping unit 10, the drive axle 13 is connected via a translation 21 with a turnstile 20. Such a turnstile 20 can be used with the same damping unit 10 as a revolving door or a similar system. In this case, it is only necessary to provide another crank element 14 or, when using a crank disc, to select a different eccentricity in order to take into account the greater mass of a revolving door in the case of damping. Due to the division in 120 ° shown here, a 1: 3 ratio has to be chosen. As far as a turnstile 20 is to be used with only about 2 or 4 locking rake, so is only the translation to adapt thereto, so a 1: 2 translation in the case of a two-part, to use a 1: 4 translation in the case of a four division. In the case of the selected 1: 3 ratio, the output shaft 16 will rotate three times during a complete revolution of the turnstile 20, that is to say three times an attenuation maximum, namely at each passage through the turnstile 20, must be overcome.

As shown in FIG. 6 is also a use of the invention for a swing door 30 is provided. It is in the region of the wall above the swinging door 30, a toothed rail 31 is provided which engages directly into the drive wheel 13 and this set in rotation. The size of the drive wheel 13 is to be selected in this case so that a complete swing corresponds to a complete revolution of the drive wheel 13. The swinging door 30 will therefore be able to swing up first, with the drive wheel 13 once rotating completely. Also in the opposite direction will be a damping in the range of the end position. It is important to note that in order to achieve an ideal damping, no complete rotation is performed, so that a rotation quasi from maximum attenuation to maximum attenuation is effected. This appears to be practicable in each case with a reciprocating movement, in a bidirectionally used turnstile 20 this is not the case. In this case, no locking mechanism must be overcome with force, but only run in the end position, for example, to automatically engage a pawl.

Another embodiment finally FIG. 7 in which a sliding door 40 is realized. In accordance with the above, a toothed strip 41, which is mounted parallel to the wall, engages in a translation associated with the drive wheel 13, so that damping is also effected by the damping unit 10 when the sliding door 40 is pushed completely open. Here, too, therefore, a damping takes place such that the sliding door reaches its end position under damping.

Thus described above is a damping unit for discontinuous damping of a rotational movement, which can be used in particular in the area of the access barriers. By implementing a continuous rotation in a non-continuous rotation, which is particularly suitable for damping, such a damping can take place in selected regions of the rotary motion, so that in particular a damping rising to the range of the end position can be realized. An ideal damping characteristic is achieved by the use of gears with unequal Wälzkurve, wherein the output-side gear is shortened in the direction of its eccentricity relative to the drive-side gear and widened in the transverse direction thereto.

LIST OF REFERENCE NUMBERS

10

damping unit

11

drive-side gear

12

output-side gear

13

drive wheel

14

crank element

15

drive axle

16

output shaft

17

Gas spring

18

piston

20

turnstile

21

translation

30

swinging door

31

dental splint

40

sliding door

41

rack

42

translation

50

Curve with same gears

51

ideal curve

52

Curve with gears according to the invention

53

point of symmetry

54

inverse curve

55

Curve of engine speed

Claims (14)

1. A dampening unit for discontinuously dampening a rotary movement of an access barrier, wherein the rotary movement is introduced by actuating the access barrier and is transferred onto a drive wheel (13) of the dampening unit connected to the access barrier and thereby introduces said rotary movement into a drive axis (15) of the dampening unit,
   comprising the drive wheel (13) rotatable around the drive axis (15),
   a discontinuous gear,
   which is configured from two unround toothed wheels (11, 12) meshing with each other, eccentrically supported, and connects said drive wheel (13) to a dampening member, which is associated to an output axis (16), of the dampening unit (10) such that the continuous rotary movement of the access barrier is transformed into a discontinuous rotary movement of the output axis (16),
   wherein the two toothed wheels (11, 12) of the discontinuous gear respectively include one extremity, however unlike rolling curves,
   wherein one toothed wheel (11) preferably supported on the drive axis (15) includes an essentially ovoid rolling curve, and a second toothed wheel (12) preferably supported on the output axis (16) includes a shorter extremity compared to the first toothed wheel (11), and is broadened in transverse direction to the direction of the extremity thereof compared to the first toothed wheel (11), wherein the toothed wheels (11, 12) include the same number of teeth, and the dampening member has two extreme positions, among one terminal position, wherein the toothed wheels (11, 12) in said extreme positions of the dampening member are oriented in the same direction and include one common symmetry axis.
2. The dampening unit according to any of the preceding claims, characterized in that the toothed wheels (11, 12) are manufactured by means of MIM or CIM technology.
3. The dampening unit according to any of the preceding claims, characterized in that the dampening member is a motor drive, which causes a, preferably position-depending, dampening at the output axis (16).
4. The dampening unit according to any of the claims 1 to 3, characterized in that the dampening unit is a dampening cylinder, the piston thereof (18) with the one free end thereof being eccentrically connected to the output axis (16), preferably with an interposed crank element (14).
5. The dampening unit according to claim 4, characterized in that the crank element (14) is a crank disc, which has associated attachment means of different eccentricities distributed along the circumference thereof for the eccentric attachment of the piston (18).
6. The dampening unit according to any of the claims 4 or 5, characterized in that the dampening cylinder is a gas-pressure spring (17), which dampens preferably only during the extension of the piston (18).
7. The dampening unit according to any of the claims 4 to 6, characterized in that a restoring element, which produces a restoring force in the direction of the nearest terminal position, is associated to the dampening cylinder.
8. The dampening unit according to any of the preceding claims, characterized in that the inverse function of the function of the rotary speed of the output axis depending on the rotary angle of the drive axis at constant rotation of the latter has the same cosine, respectively sine-shaped course.
9. The dampening unit according to any of the preceding claims, characterized in that the discontinuous gear is accommodated in a housing, which is preferably composed of two identical half-shells and is preferably filled with transmission oil.
10. The dampening unit according to any of the preceding claims, characterized in that the output-sided toothed wheel (12) is integrally manufactured with the output axis (16) and the drive-sided toothed wheel (11) is integrally manufactured with the drive axis (15).
11. The dampening unit according to any of the preceding claims, characterized in that the drive wheel (13) is connected to the access barrier via a transmission, preferably a transmission (21, 42) with a ratio 1:4, 1:3 or 1:2.
12. The dampening unit according to claim 11, characterized in that the drive axis (15) and/or the output axis (16) are/is formed, at least portionwise, as a toothed shaft, wherein preferably the number of the teeth of the drive wheel (13) is an integer multiple of the number of the teeth of the toothed shaft portion.
13. The dampening unit according to any of the claims 11 or 12, characterized in that an additional toothed wheel is coaxially associated to the drive wheel (13) or to the transmission (42) and engages into a toothed strip (41) and the toothed strip (41) may be disposed in the area of a wall.
14. The dampening unit according to any of the claims 1 to 12, characterized in that the drive wheel (13) is configured as a toothed wheel, into which engages a toothed rail (31).

Images