CN101680256B

CN101680256B - Fitting for a window, door or similar

Info

Publication number: CN101680256B
Application number: CN2008800112090A
Authority: CN
Inventors: 彼得·施塔普夫
Original assignee: Roto Frank AG
Current assignee: Roto Frank AG
Priority date: 2007-04-02
Filing date: 2008-03-14
Publication date: 2013-06-26
Anticipated expiration: 2028-03-14
Also published as: CN101680256A; EA014799B1; HRP20120981T1; PL2142736T3; SI2142736T1; WO2008119451A1; EP2142736A1; EA200970904A1; UA92698C2; EP2142736B1; DE102007017452A1

Abstract

The invention relates to a fitting for a window, door or similar, comprising a corner bend, a driving rod that is connected to the corner bend and that forms an upper rail and a scissor-type deployment arm that is associated with a supporting arm unit. According to the invention, the supporting arm unit (17) has a base part (18) and a supporting arm (19) that is pivotally mounted on the base part (18) by means of a detachable rotary lock (20).

Description

Fitting for windows, doors or the like

Technical Field

The invention relates to a fitting for windows, doors or the like, comprising a corner piece, a connecting rod connected to the corner piece and forming an upper rail, and a telescopic actuating arm associated with a bearing arm device.

Background

In principle, the fittings mentioned above are known. They are usually arranged on a movable sash frame of a window, door or the like for connecting the sash frame with a stationary frame rim. The fitting comprises a corner piece to which a link forming an upper rail and a telescopic switch arm are connected, which allows the sash to be opened both by rotation and by tilting. A support arm arrangement is associated with the telescopic switching arm for supporting and guiding the telescopic switching arm and the corner piece.

Disclosure of Invention

It is an object of the present invention to provide a fitting which is simple in manufacturing process, low in cost, and easy to install, remove and/or maintain.

The object of the invention is achieved in that the support arm arrangement has a base part and a support arm, which is arranged rotatably on the base part by means of a releasable rotary locking device. That is, the support arm assembly has a support arm rotatably disposed on a base member and a releasable rotational locking arrangement is disposed to releasably interconnect the support arm and the base member. The rotational locking device locks or stops the support arm on the base part by rotation of the support arm and/or the base part, thereby preventing the support arm and the base part from being accidentally released. By means of this rotary locking device, the mounting arm arrangement is particularly easy to mount and dismount, so that the assembly and disassembly work of the fitting as a whole is simplified.

According to one embodiment of the invention, the rotary locking device is formed by a keyhole-shaped through-hole in the base part and a key-shaped bearing pin which is fixed in a rotationally fixed manner to the supporting arm. The base part has a keyhole-shaped opening which cooperates with a key-shaped bearing pin on the supporting arm to form the rotary locking device. The keyhole-shaped passage and the key-shaped bearing pin are formed such that the bearing pin can be inserted into the passage or removed from the passage in only one rotational angle position. If the bearing pin is rotated in the inserted state, the rotary locking device is locked and the bearing pin cannot be removed from the through-hole or released from the base part. By fixing the bearing pin to the bearing arm in a rotationally fixed manner, the rotational movement of the bearing arm is easily transmitted to the bearing pin. This also has the result that the bearing pin is pivoted in dependence on the bearing arm, so that the rotary locking mechanism can only be released in dependence on the (rotary) position of the bearing arm.

It is advantageous if the rotary locking device can be locked or unlocked only at rotational angular positions outside the working rotational region of the bearing arm. In the case of a tilted opening of the fan frame, the telescopic switching arm is pivoted out, so that the supporting arm likewise moves or pivots. The working pivoting area of the supporting arm is thus dependent on the angular opening angle of the fan frame. The keyhole-shaped passage and the key-shaped bearing pin are formed such that the rotary locking device (as described above) is released only in a rotational angular position of the bearing pin to the passage, which rotational angular position is outside the working pivot region of the bearing arm. That is, the rotational locking device is not released in the normal use state of the assembled fitting.

In a preferred embodiment of the invention, the base member and the corner piece are removably interconnected. The base part is a component which is machined separately from the corner piece and is detachably connected to the corner piece. The fitting is thus of modular construction, so that the corner pieces, preferably made of plastic, can in principle also be used for other positions/corners of the fan frame, and an advantageous fitting with a telescopic switching arm is realized by means of a detachable base part. The bottom part is preferably formed by a plastic bottom part.

In a preferred embodiment of the invention, the base part is connected to the corner piece by a positive-locking connection. That is to say that the base part and/or the corner part have means by which a form-locking connection can be formed. By using a form-locking coupling, bolts or other fasteners are not necessary, thereby simplifying the assembly process.

The form-locking coupling is preferably perpendicular to the longitudinal extension of the connecting rod. In other words, for adjusting the form-locking connection perpendicular to the longitudinal extension of the connecting rod, the base part and the corner piece are moved relative to one another, so that the form-locking is effected in particular in the longitudinal extension of the connecting rod.

Furthermore, the form-locking connection is preferably a C-groove/T-head connection. In other words, the base part has a C-shaped groove or a T-shaped head which interacts with the T-shaped head or the C-shaped groove of the corner piece, wherein the T-shaped head is inserted or engages into the C-shaped groove in the positive-locking coupling direction. The T-shaped head here forms a rear engagement (hindtergriff) in the C-shaped groove, so that the base part and the corner part are preferably fixed to one another in the longitudinal extension of the connecting rod.

According to one embodiment of the invention, the support arm has a pin, by means of which the support arm is rotatably arranged on the telescopic switching arm. According to the invention, the telescopic switching arm has a corresponding opening into which the pin is inserted. This pin is preferably arranged at the end of the support arm opposite the bearing pin.

This pin is preferably an eccentric pin, so that the geometrical position between the telescopic switch arm and the support arm and the tilting movement of the fan can be adjusted by rotation of the pin. For example, manufacturing tolerances and/or wear of the fitting can be compensated for by the eccentric pin. Thus, by adjusting the eccentric pin accordingly when mounting the fitting, the closing of the window can be adjusted accurately, thereby ensuring the tightness of, for example, windows, doors, etc.

In order to facilitate the rotational positioning of the eccentric pin and to avoid an unwanted rotation of the eccentric pin during operation, the eccentric pin preferably has an adjustment contour plate in the center of the bearing arm, which cooperates with a spring tongue with an opposing adjustment contour plate to prevent rotation, wherein the spring tongue is fixed to the bearing arm in a rotationally fixed manner. That is to say, the adjusting contour plate of the eccentric pin can be pivoted about the center and can be locked in a plurality of rotational positions by the opposing adjusting contour plate of the spring tongue. In this way, the eccentric pin can be locked in a plurality of rotational positions on the bearing arm, so that the eccentric pin cannot rotate by itself in the operating state.

The eccentric bolt preferably has a flange below the adjusting contour plate, which flange forms an axial distance between the adjusting contour plate and the bearing arm for the purpose of sinking relative to the adjusting contour plate during eccentric adjustment. That is, the eccentric pin has a flange below the adjustment contour plate, which defines the axial distance of the adjustment contour plate from the bearing arm. According to the invention, a flanged eccentric pin is placed on the support arm. The spring tongue with the relative adjustment profile can thus be easily displaced into the area between the adjustment profile plate and the support arm, thereby releasing the adjustment profile plate and enabling it to rotate. According to the invention, the spring tongue, which is elastic in itself, can easily sink into the space between the support arm and the adjustment contour plate under the influence of force. Due to its own elasticity, the spring tongue returns after removal of the applied force to a starting position in which the counter-adjusting contour plate co-acts with the adjusting contour plate. In order to adjust the direction of the eccentric pin, the spring tongue can be easily pressed down and the eccentric pin can be rotated. This simplifies the adjustment of the fitting during assembly and maintenance.

The adjustment contour of the adjustment contour plate is preferably a polygonal contour. The adjustment contour plate and the counter-adjustment contour plate are also polygonal, which can engage with each other, so that the eccentric pin can be stopped in a plurality of rotational positions.

Preferably, the counter-adjusting contour plate is a dovetail-shaped contour, which accordingly interacts with the adjusting contour plate. By means of this preferred embodiment, it is ensured that the region of the counter-adjusting contour plate or of the spring tongue with the counter-adjusting contour plate can easily be lowered.

Furthermore, the spring tongue essentially coincides with the support arm. In this way, the fitting preferably narrows as a whole. In addition, the spring tongues are prevented from catching on or hitting the edges of fittings and/or other elements of the fan frame and/or the rim.

Finally, a stop element is provided on the telescopic switching arm, which enables the telescopic switching arm to be arranged on the frame. In particular, such a locking element interacts with a hinge bolt arranged on the rim.

Drawings

The present invention will be described in detail below with reference to the accompanying drawings. Wherein,

FIG. 1 is an embodiment of a fitment according to the present invention in a tilted open position;

FIG. 2 is an enlarged view of the support arm arrangement of the accessory;

FIG. 3 is a bottom view of the support arm assembly in a tilted open position;

the fitting is in the closed position in FIG. 4;

FIG. 5 is a bottom view of the support arm assembly in a closed position;

FIG. 6 is another embodiment of a fitment according to the present invention in a tilted open position;

fig. 7 is an enlarged view of a support arm arrangement in another embodiment.

Detailed Description

Fig. 1 is a perspective view of an embodiment of a fitting 1 for movably connecting a sash frame of a window, door or the like with a corresponding frame rim. The fitting 1 has an angled piece 2 which is formed by two

legs

3, 4 forming a right angle. On each leg 3, 4 a

linear guide

5, 6 is formed, in which a slide 7, 8, respectively, slides. The slides 7, 8 are connected to each other by a counter-drive which is flexible but still strong enough to transmit pressure and/or tensile forces, so that the movement of the slide 7 or 8 can be transmitted directly to the other slide 8 or 7. The connecting rod 9 is connected to the slide 8 by means of a connecting bolt 10, so that the longitudinal movement of the slide 8 along the linear guide 6 is transmitted to the connecting rod 9 (or vice versa). Here, the connecting rod 9 forms an upper rail 11 of the fitting 1.

The fitting 1 also has a telescopic switch arm 12, one end of which is moved in a first guide groove 14 of the connecting rod 9 by means of a guide pin 13 and the other end of which is movably fixed to the rim by means of a stop element 15. For this purpose, the stop element 15 has a clamping element 16 which receives a movable bolt fixed to the rim.

The fitting 1 furthermore has a supporting arm arrangement 17, which corresponds to the telescopic switching arm 12. The support arm arrangement 17 has a base part 18 which is connected to the leg 4 of the corner piece 2, and a support arm 19 which is rotatably arranged on the base part 18 and the telescopic switch arm 12.

The supporting arm 19 is fixed to the base part 18 by a detachable rotary locking device 20 which passes through the connecting rod 9 in a second guide slot 21. At the other end opposite the rotary locking mechanism 20, the supporting arm 19 is rotatably fixed to the telescopic switching arm by means of a pin 23 formed by an eccentric pin 22, which engages in a through-opening 24 in the telescopic switching arm 12.

Fig. 2 is an enlarged exploded view of the support arm arrangement 17, wherein the connecting rod 9 is not shown. The base part 18 has a keyhole-shaped through-opening 25, into which a key-shaped bearing pin 26 can be inserted, which is arranged on the supporting arm 19 in a rotationally fixed manner. The bearing pin 26 has a radial projection 29 on its free end 27, which forms a key bit 28 and which can be inserted into a corresponding radial recess 30 in the keyhole-shaped passage 25. The region of the shaft of the bearing pin 26 that can pass through the bore 25 is substantially cylindrical. At the other end 31, opposite the end 27, the bearing pin 26 has a substantially oval cross-section with two mutually parallel sides. The supporting arm 19 has a correspondingly shaped recess, so that the bearing pin 26, which engages in the recess of the supporting arm 19, is connected in a rotationally fixed manner to the supporting arm 19 by the oval shape of its end 31. In fig. 2, the rotary locking device 20 is in the unlocked position, so that the bearing pin 26 can be inserted into the passage opening 25.

Fig. 3 is a bottom view of the rotational locking device 20 in a locked state. The bottom part 18 has on the underside an opening 32 concentric with the keyhole-shaped passage 25, which forms a recess, in which the key bit 28 can be rotated after passing through the radial recess 30, so that a back-engaging counter surface is formed between the bearing pin 26 and the bottom part 18, which prevents the rotational lock mechanism 20 from being loosened in the axial direction. Since only the radial recesses 30 are provided, the bearing pin 26 can be inserted into the keyhole opening 25 only in a single position. This position is preferably outside the working rotation area of the bearing arm 19. Furthermore, as shown in fig. 3, the base part 18 is connected to the corner piece 2 or the legs of the corner piece 2 by a positive-locking connection 33. The bottom part 18 is provided at its end 4 adjacent to the leg with a C-shaped groove 34 into which the T-shaped head 35 of the leg 4 of the corner piece 2 is placed. The T-head 35 is integral with the corner piece 2. As shown in fig. 2, the C-shaped groove 34 and the T-shaped head 35 do not occupy the entire height of the base part 18 or the corner piece 2, so that the T-shaped head 35 can be inserted from below into the C-shaped groove 34 of the base part 18 until a bearing surface, not shown, which adjoins the C-shaped groove 34 from above. This form-locking coupling is therefore perpendicular to the longitudinal extension of the connecting rod 9.

Furthermore, it is seen in fig. 2 that the eccentric pin 22 has an adjustment contour plate 36 located in the center of the supporting arm 19. This adjustment contour plate 36 interacts with a spring tongue with an opposing adjustment contour plate 37, which is fixed in a rotationally fixed manner to the supporting arm 19. For this purpose, the spring tongue 38 has an opening 39 at its end opposite the relative adjustment contour plate 37, whose contour corresponds to the cross section of the end 31 of the bearing pin 26. The spring tongue 38 substantially overlaps the support arm 19. The adjustment contour plate 36 is polygonal in shape and cooperates with an opposing adjustment contour plate 37 having a dovetail-shaped contour 40 to enable the bearing pin 22 to rotate as desired. The end of the spring tongue 38 with the opening 39 rests on the support arm 19. Due to the step in the spring tongue, the region 41 of the spring tongue 38 with the adjusting contour plate 37 is spaced at a distance from the bearing arm 19. Below the adjusting contour plate 36, the eccentric pin 22 has a flange 42 which determines the axial distance between the adjusting contour plate 36 and the bearing arm 19. The flange 42 is smaller in cross-section than the adjustment contour plate 36. To adjust the eccentric pin 22, the spring tongue 38 is pressed down or pressed against the supporting arm 19 in the region 41, so that it sinks downwards relative to the adjustment contour plate 37 and releases the adjustment contour plate 36 so that it can rotate along the central axis. As soon as the load on the spring tongue 38, which is elastic in itself, or on the region 41 of the spring tongue 38, is removed, the relative adjustment contour plate 37 engages with the adjustment contour plate 36, so that the eccentric pin 22 is stopped in its (eccentric) position. By rotation of the eccentric pin 22, for example, manufacturing tolerances and/or wear of the fitting 1 and/or of the window, door, etc. with the fitting 1 can be compensated. Furthermore, an annular spacer 43 is arranged between the supporting arm 19 and the bottom part 18, through which spacer the bearing pin 26 passes. The annular spacer 43 serves to space the support arm 19 from the base part 18 and the corner piece 2 so that the support arm 19 does not run into the edges of the other parts and wear is minimized. The connecting bolts 10 connecting the connecting rod 9 to the slide 8 can be inserted into the slotted openings 44 of the slide 8 at several different longitudinal positions, so that the connecting rod 9 is matched in length. The corner piece 2 consists of two parts so that the sliders 8 and 7 can be inserted into the respective

linear guide

5 or 6 in a simple manner.

In fig. 4 the fitting 1 is in the closed position, in which the telescopic switch arm 12 substantially coincides with the leg 4 and the link 9 of the corner piece 2. The closing bolt 45 shown in fig. 1 and 2, which is fastened to the slide 8, interacts in the closed position, which is achieved by the longitudinal displacement of the connecting rod 9 or the displacement of the slide 8, with a closing plate 46, which is arranged on the telescopic actuating arm 12, so that the window or the sash frame of the window with the corner piece 2 does not tilt open.

When the fitting 1 is in the closed position, the key bit 28 of the bearing pin 26 is offset by 180 ° from the radial recess 30 of the keyhole-shaped through-hole 25 in the bottom part 18, as shown in the bottom view of the rotary lock device 20 in fig. 5. The operative pivoting area of the supporting arm 19 is determined by the tilted open position shown in figure 3 and the closed position shown in figure 5. By means of the arrangement and design of the key-like bearing pin 26 and the keyhole-like passage opening 25, the rotary locking mechanism is released or locked only outside the working pivot region of the bearing arm 19.

When mounting the fitting 1, the base part 18 is first placed over the T-shaped head of the foot 4 to form a positive-locking connection 33 between the base part 18 and the corner piece 2, so that the support arm arrangement 17 is positioned precisely. The corner piece 2 and the bottom piece 18 are then placed in the bending space of the fan frame and fixed by means of screws, for which purpose the bottom piece 18 and the corner piece 2 are provided with threaded holes 47. The connecting rod 9 is then fixed in longitudinal position on the slide 8 by means of the connecting bolt 10. The support arm 19, which comprises the annular washer 43 and the spring tongue 19, is then connected rotatably to the bottom part 18 by means of the bearing pin 26, so that the rotary locking mechanism 20 is formed. Here, the bearing pin is rotated after it is inserted into the through hole 25, thereby forming the aforementioned rear engagement. The telescopic switch arm 12 is then fixed to the rim by means of the stop element 15 and is connected to the supporting arm arrangement 17 and the connecting rod 9 by means of the guide pin 13 and the eccentric pin 22.

Due to the advantageous design of the fitting 1, the fitting 1 will be particularly simple to assemble, disassemble and maintain.

Figures 6 and 7 are respectively perspective views of another embodiment of a fitting 1 according to the invention, wherein this embodiment is substantially identical to the embodiment shown in figures 1 to 5, and therefore identical parts have the same reference numerals and reference is made to the description of the previous figures. Only the differences are referred to below.

In fig. 6 is an embodiment of a fitting 1 for a large fan frame, in an obliquely open position. In contrast to the previous embodiment, the base part 18 is spaced from the corner piece 2. Between the corner piece 2 and the bottom piece 18 there is further provided a link guide element 48, which is spaced from both the corner piece 2 and the bottom piece 18 and which engages in an elongated hole-shaped opening 49 of the link 9 forming a further guide groove. The link guide member 48 has a receiving hole 50 which is identical to the threaded hole 47 of the previous embodiment.

The bottom part 18 is longer than in the previous embodiment, viewed in the longitudinal direction of the connecting rod 9, and has a breakable plug 51 which snaps into a through-hole 52 in the connecting rod 9 formed by a drilled hole. The breakable stopper is used to position the base member on the connecting rod when assembled. When the fitting 1 is operated for the first time, it can be easily cut off, so that the connecting rod can be moved.

Fig. 7 is a partially enlarged view of the support arm device 17. The guide slot 21 of the connecting rod 9 has a first region 53 through which the bearing pin 26 of the rotary locking device 20 passes; it also has a relatively narrow second region 54 in which a further link guide element 55 engages. Here, the link guide element 55 interacts with the base part 18 and likewise has a threaded bore 47 for fastening the base part 18 and the link guide element 55 to the sash frame.

The support arm arrangement 17 differs from the previous embodiments in that a stop washer 56, which can be pivoted about the bearing pin 26, is arranged on the support arm 19, which stop washer substantially coincides with the support arm 19. The stop washer 56 has, at its end opposite the bearing pin 26, an upwardly directed, i.e. bent, positioning edge 57 which projects from the bearing arm 19 and which interacts with the adjusting contour plate 36 of the eccentric pin 22 in such a way that the latter cannot rotate. The flange 42 described in the previous embodiment below the adjustment contour plate 36 is no longer required in this embodiment, so that the overall height of the support arm arrangement 17 in this embodiment is relatively small. In addition, the stop washer 56 has a projection 58 generally centrally which cooperates with a recess or perforation, such as a bore, in the support arm 19 to retain the stop washer 56 in the stop position, as shown. The projection 58 snaps or bites into a notch or perforation in the support arm 19. In addition, the stop washer 56 has an operating edge 59 projecting, i.e., facing upwards, from the support arm 19 on each side adjacent to the positioning edge 57. The operating edge 59 forms an action/operating point for the user to pivot the stop washer 56 about the bearing pin 26. Once the stop washer 56 is rotated, the eccentric pin 22 may be rotated or adjusted. Here, the projection 58 projects outwardly from a recess or perforation of the support arm 19. The positioning edge 57 preferably has a radius of curvature which facilitates or enables the rotation of the stop washer 56. After adjustment of the eccentric pin 22, the stop washer 56 can be easily returned to the stop position, while the projection 58 snaps into/onto the bearing arm 19.

As shown in fig. 6, another difference is that the guide pin 13 of the telescopic switch arm 12 is not movable in the guide groove 14, but is connected to a guide slider 60, which is fitted over the link 9. Furthermore, the telescopic switching arm 12 has a further closing plate 61, which interacts with a further closing bolt 62, which is fastened to the connecting rod 9.

When assembling the fitting 1 here, it is typical to first fix the corner piece 2 to the fan frame. The connecting rod 9, comprising the base part 18 and the connecting rod guide element 48, is then placed in the folding space of the sash frame and fixed, wherein the connecting rod 9 is fixed to the slide 8 by means of the connecting bolt 10. Since the breakable plug 51 aligns and secures the bottom part 18 when assembled on the connecting rod 9, the bottom part 18 can be accurately positioned and assembled without direct connection or direct contact with the legs 4 of the corner piece 2 and without the use of assembly jigs. Once the corner piece 2 and the connecting rod 9 including the bottom piece 18 and the connecting rod guide element 48 are mounted in the folding space of the sash frame, the bottom piece 18 and the connecting rod guide element 48 can be fixed to the sash frame by means of bolts passing through the threaded holes 47. The support arm assembly 17 is then mounted using the rotational lock assembly 20 as described in the previous embodiment and connected to the telescoping switch arm 12 in the tilt open position as shown.

Alternatively, the fitting 1 has been pre-fitted in the folding space of the fan frame, so that it has to be bolted to the fan frame.

When the fitting 1 is operated for the first time, the link 9 is pushed, and the breakable plug 51 is also broken, thereby allowing the link 9 to move freely. Advantageously, the link guide element 48 also has corresponding fitting or positioning means, for example a breakable plug, so that the link guide element 48 can be easily positioned on/in the link 9 during fitting.

Claims

1. Fitting (1) for windows and doors, comprising a corner piece (2), a connecting rod (9) connected to the corner piece (2) and forming an upper rail (11), and a telescopic switching arm (12) associated with a support arm arrangement (17), characterized in that the support arm arrangement (17) has a base part (18) and a support arm (19), which is pivotably arranged on the base part (18) by means of a releasable rotary locking device (20), and in that the base part (18) is connected to the corner piece (2) by means of a form-locking connection (33) which runs perpendicular to the longitudinal extension of the connecting rod (9).

2. Fitting according to claim 1, characterized in that the rotation locking device (20) is formed by a keyhole-shaped through-hole (25) in the base part (18) and a key-shaped bearing pin (26) which is fixed in a rotationally fixed manner to the bearing arm (19).

3. Fitting according to one of the preceding claims, characterized in that the rotational locking device (20) can only be locked or unlocked in rotational angular positions outside the working rotational region of the bearing arm (19).

4. An accessory according to claim 1, characterized in that the bottom piece (18) and the corner piece (2) are detachably interconnected.

5. Fitting according to claim 1, characterized in that the form-locking coupling (33) is a C-shaped groove (34) and T-shaped head (35) connection.

6. An accessory according to claim 1, characterized in that the supporting arm (19) has a pin (23) by means of which the supporting arm is rotatably arranged on the telescopic switch arm (12).

7. Fitting according to claim 6, characterized in that the pin (23) is an eccentric pin (22).

8. Fitting according to claim 7, characterized in that the cam pin (22) has an adjustment contour plate (36) in the center of the bearing arm (19) which cooperates with a spring tongue (38) with an opposite adjustment contour plate (37) in order to prevent rotation, wherein the spring tongue (38) is fixed in a rotationally fixed manner to the bearing arm (19).

9. The fitting according to claim 8, characterized in that the eccentric pin (22) has, below the adjustment contour plate (36), a flange (42) which forms an axial spacing between the adjustment contour plate and the support arm (19) for the purpose of sinking relative to the adjustment contour plate (37) during eccentric adjustment.

10. An accessory according to claim 8, characterized in that the adjustment contour plate (36) is of a polygonal contour.

11. Accessory according to claim 8, characterized in that the relative adjustment contour plate (37) is a dovetail-shaped contour (40).

12. Fitting according to claim 8, characterized in that the spring tongue (38) substantially coincides with the supporting arm (19).

13. An accessory according to claim 1, characterized in that a stop element (15) is provided on the telescopic switch arm (12).