Device for laterally guiding the upper end of an extendable piece of furniture

Description

[0001] The invention relates to a device for laterally guiding the upper end 1 of an extendable furniture part, which can be extended from a position completely inserted into a furniture body in a pull-out direction to a position completely pulled out of the furniture body, comprising a guide rail which can be fastened to the furniture body and whose longitudinal extent is parallel to the pull-out direction.

[0002] A device of the type mentioned above is known from EP 1 721 547 B1. The device serves to laterally guide the upper end of a pull-out tall cabinet section to prevent it from tipping sideways. The pull-out tall cabinet section is arranged upright on a lower pull-out guide. The device for laterally guiding the upper end of the pull-out tall cabinet section has telescopically extendable rails. A carcass rail is attached to the furniture carcass. An upper frame leg of the pull-out tall cabinet section is designed as a pull-out rail. A middle rail is arranged between them. This enables the pull-out tall cabinet section to be fully extended or over-extended. The design is robust and functional, but also relatively complex. It also requires additional installation space in relation to its height due to the three interlocking rails, which reduces the usable height of the pull-out tall cabinet section.In addition, when the pull-out tall cabinet section is extended, the fittings extend over the depth of the pull-out tall cabinet section, which prevents loading of the pull-out tall cabinet section from above.

[0003] This can be undesirable, especially with pull-out furniture that is not too high.

[0004] From US 3 784 274 A a device for laterally guiding the upper end of an extendable furniture part is known, in which a pivotable rotating piece interacts with a mounting piece in a position which can be changed relative to one another.

[0005] The object of the invention is to provide an advantageous device of the type mentioned above, which, with a simple design, enables full or over-extension of the pull-out furniture part. According to the invention, this is achieved by a device having the features of claim 1.

[0006] The device according to the invention has a rotating piece guided by the guide rail parallel to the extension direction, which is pivotally mounted on a mounting piece about a horizontal axis of rotation lying at right angles to the extension direction. The mounting piece can be fastened to the extendable furniture part, in particular in the region of its rear end relative to the extension direction. The mounting piece can be displaced from an inserted position, which can be assumed by the mounting piece when the extendable furniture part is fully inserted, in the extension direction via a displacement path into an extended position, which can be assumed by the mounting piece when the extendable furniture part is fully extended. In the inserted position of the mounting piece, the rotating piece rests against an insertion end stop of the guide rail, wherein it has an inserted rotational position about the axis of rotation relative to the mounting piece.In the extended position of the mounting piece, the rotating piece rests against an extension stop of the guide rail, assuming an extended rotational position about the rotation axis relative to the mounting piece. The extended rotational position is rotated about the rotation axis relative to the inserted rotational position, preferably by more than 60°, particularly preferably by more than 90°.

[0007] By rotating the rotating piece, guided by the guide rail, around the rotation axis, the displacement path over which the mounting piece can be moved between the inserted and extended positions can be extended. This displacement path can thus be longer than the distance between the insertion end stop and the extension end stop of the guide rail. This allows for a relatively simple design to implement lateral guidance for a full-extension or over-extension pull-out of the pull-out furniture part.

[0008] If the mounting piece is mounted on the pull-out furniture part in the area of ​​the rear end of the pull-out furniture part, access to the pull-out furniture part from above is not obstructed by the inventive device for lateral guidance of the pull-out furniture part. The pull-out furniture part can thus be loaded from above.

[0009] The usable height of the extendable furniture section can also be maximized.

[0010] Preferably, when the mounting piece is displaced in the pull-out direction starting from the insertion position of the mounting piece, at least over an initial section of the displacement path, the interaction of the rotating piece with a first engagement element of the guide rail causes a rotation of the rotating piece about the rotation axis relative to the mounting piece, wherein during the further displacement of the mounting piece over a main section of the displacement path following the initial section, the rotational position of the rotating piece about the rotation axis relative to the mounting piece remains unchanged.

[0011] It is preferred that when the mounting piece is displaced in the pull-out direction, at least over an end section of the displacement path before reaching the pull-out position of the mounting piece, a rotation of the rotating piece about the rotation axis relative to the mounting piece is effected by the interaction with a second engagement element of the guide rail.

[0012] However, it would also be conceivable and possible that such a rotation of the rotating piece about the rotation axis relative to the mounting piece is effected either only over the initial section of the displacement path or only over the final section of the displacement path of the mounting piece.

[0013] If, when the mounting piece is moved over the initial section of the displacement path, a rotation of the rotating piece about the axis of rotation is caused, which is preferred, this rotation of the rotating piece is advantageously dampened by a damper when the mounting piece is pushed in against the pull-out direction over the initial section of the displacement path until the insertion position of the mounting piece is reached.

[0014] If, when the mounting piece is pulled out in the pull-out direction over the end section of the displacement path, a rotation of the rotating piece about the rotation axis is caused, which is preferred, this rotation is advantageously dampened by a damper.

[0015] In particular, a single damper can be provided which dampens both the extension of the mounting piece over the end section of the displacement path and the insertion of the mounting piece over the initial section of the displacement path.

[0016] To dampen the displacement of the mounting piece over the final section of the displacement path when the mounting piece is pulled out and / or over the initial section of the displacement path when the mounting piece is pushed in, a rotary damper is advantageously provided. The rotary piece can have a toothing coaxial with the rotation axis, which meshes with a toothing coupled to the damper and extending along a circle or circular arc.

[0017] The guide rail advantageously has a receiving space defined by first and second side legs, which is open at the bottom, with the rotating piece projecting into this receiving space from below. The side legs advantageously project downwards from a horizontal base web. away. The guide rail therefore has a U-shaped cross-section.

[0018] Advantageously, the insertion end stop is formed by a portion of the lateral surface of a bolt of the guide rail, which engages with a guide track of the rotating piece when the mounting piece is moved over the initial section of the displacement path. This bolt forms a first engagement element of the guide rail, which causes the rotating piece to rotate about the rotation axis when the mounting piece is moved over the initial section of the displacement path.

[0019] The extension end stop is advantageously formed by a section of the outer surface of a bolt of the guide rail, which engages with a guide track of the rotating piece when the mounting piece is moved over the end section of the displacement path. This bolt forms a second engagement element of the guide rail, which causes the rotating piece to rotate about the rotation axis when the mounting piece is moved over the end section.

[0020] Further advantages and details of the present invention are explained below with reference to the accompanying drawings, in which: Fig. 1 is an oblique view of a tall cabinet with a device according to the invention in accordance with an embodiment of the invention in the fully inserted position of the pull-out furniture part; Fig. 2 is a representation corresponding Fig. 1 in the fully extended position of the pull-out furniture part; Fig. 3 a representation corresponding Fig. 2 from a different perspective, with parts of the furniture body removed; Fig. 4 a side view of the device for lateral guidance in a middle position of the mounting piece; Fig. 5 a section along the line AA of Fig. 4 ; Fig. 6 a section along the line BB of Fig. 4 ; Fig. 7 an oblique view of the device for lateral guidance in a middle position of the mounting piece; Fig. 8 an oblique view corresponding Fig. 7 from a different viewing direction (obliquely from below and from the opposite side); Fig. 9 an oblique view of the unit guided by the guide rail, in the position it assumes in the inserted position of the mounting piece; Fig. 10 a representation analogous Fig. 9, but in the position which the unit assumes in the extended position of the mounting piece; Fig. 11 and 12 exploded views from different viewing directions; Fig. 13 an oblique view of the device in the inserted position of the mounting piece, the guide rail only partially shown and the front side leg of the guide rail removed; Fig. 14 a representation analogous Fig. 13 in the extended position of the mounting piece; Fig. 15 a side view of the unit, the guide rail only partially shown and the front side leg removed, in the inserted position of the mounting piece; Fig. 16 a representation analogous Fig. 15 , but the assembly piece when pulled out in a position in a middle area of ​​the initial section of the displacement path; Fig. 17 a representation analogous Fig. 15 , but the assembly piece when pulled out in the position at the end of the initial section of the displacement path; Fig. 18 a representation analogous Fig. 15, but the assembly piece when pulled out in a position at the beginning of the final section of the displacement path; Fig. 19 a representation analogous Fig. 15 , but the assembly piece when pulled out in a position in a middle area of ​​the end section of the displacement path; Fig. 20 a representation analogous Fig. 15 , but the mounting piece in the extended position; Fig. 21 a representation analogous Fig. 15 , but the mounting piece when inserted in a position at the end of the end section of the extension path; Fig. 22 a representation analogous Fig. 15 , but the mounting piece when inserted in a position at the beginning of the initial section of the extension path.

[0021] An embodiment of the invention is explained below with reference to the figures. The device according to the invention serves for laterally guiding the upper end of a furniture part that can be pulled out of a furniture body 1 in a pull-out direction 8 and pushed in opposite to the pull-out direction 8. 2.The furniture shown is a tall cabinet. The pull-out furniture section 2 is guided by a single pull-out guide 3, which is located centrally below the pull-out furniture section 2. This guide can be extended between a fully retracted position (see figure). Fig. 1 and a fully extended position, cf. Fig. 2 and 3 . The extension guide 3 can, for example, be a differential extension. Other types of extension guides can also be used, such as telescopic extensions.

[0022] The pull-out guide 3 preferably enables full extension or over-extension.

[0023] The device according to the invention can also be used in furniture other than tall cabinets. The use of a device according to the invention is particularly useful when the pull-out furniture part is guided by only a single, centrally located pull-out guide.

[0024] The device according to the invention has a guide rail 4 which is to be fastened to the furniture body 1, in particular to the underside of a ceiling part of the furniture body 1.

[0025] The device according to the invention further comprises a unit 5, which is to be attached to the extendable furniture part. This unit 5 comprises a mounting piece 6, via which the attachment to the extendable furniture part 2 is effected, and a rotating piece 7, which is displaceably guided by the guide rail 4 parallel to the extension direction 8, which is parallel to the longitudinal extent of the guide rail 4. With respect to the opposite horizontal directions, which are perpendicular to the extension direction 8, the rotating piece 7 is supported by the guide rail 4 against displacement in these directions (apart from any bearing play).

[0026] The rotating piece 7 engages from below into a downwardly open receiving space 9 of the guide rail 4. The receiving space is delimited in the opposite horizontal directions, which are perpendicular to the extension direction 8, by side legs 10, 11 of the guide rail 4. These side legs 10, 11 protrude downward from a horizontal base web 12 of the guide rail 4. These side legs 10, 11 thus support the rotating piece 7 against displacement in the horizontal directions perpendicular to the extension direction 8. The guide rail 4 has a U-shaped cross-section.

[0027] In the region of its rear end relative to the extension direction 8, the guide rail 4 has a first engagement element 13, which in the exemplary embodiment is formed by a bolt running horizontally and at right angles to the extension direction 8 between the side legs 10, 11. In the region of its front end relative to the extension direction 8, the guide rail 4 has a second engagement element 14, which in the exemplary embodiment is formed by a bolt running horizontally and at right angles to the extension direction 8.

[0028] As already mentioned, the mounting piece 6 is mounted on the extendable furniture part 2 in the area of ​​the rear end thereof with respect to the extension direction 8, for example in the area of ​​the upper end of an upper rear wall part 2a of the extendable furniture part. This upper rear wall part 2a has a recess extending from the upper edge, into which the mounting piece 6 is inserted. The mounting piece 6 has a cutout 15 on its underside, so that the lower section has a U-shape. With this cutout, the mounting piece 6 is placed onto the lower edge of the recess in the rear wall part 2a and screwed to the rear wall part 2a in this area. Other types of attachment to the rear wall part 2a are also possible.

[0029] In the illustrated embodiment of the extendable furniture part, the upper rear wall part 2a is height-adjustable relative to a lower rear wall part 2b of the extendable furniture part and can be fixed in the adjusted position by means of screws.

[0030] The rotating piece 7 is pivotally mounted (=rotatable to a limited extent) by the mounting piece 6 about a horizontal axis of rotation, which is perpendicular to the extension direction 8. The rotating piece 7 can be rotated from an insertion position to an extension direction to an extension position. In the extension position, further rotation in the extension direction is blocked; in the insertion position, further rotation opposite to the extension direction is blocked.

[0031] The area over which the rotating piece 7 engages in the receiving space 9 of the guide rail 4 represents an engagement section 21 of the rotating piece 7. On the side opposite the engagement section 21, the rotating piece 7 has a web-like extension 22, which lies in a vertical plane parallel to the extension direction 8. This extension 22 projects into a slot 16 of the mounting piece. 6. A through-opening 17 through the mounting piece 6 passes through this slot 16. This through-opening 17 is coaxial with a through-opening 22a through the extension 22. A pin 19 forming the rotation axis 20 passes through the through-opening 17 of the mounting piece 6 and the through-opening 22a of the extension. The through-openings 17, 22a are thus coaxial with the rotation axis 20.

[0032] The extension 22 has a toothing 22b on its narrow side facing away from the engagement section 21, which extends over a circular arc. When the rotating piece 7 rotates about the rotation axis 20, the toothing 22b rotates about the rotation axis 20.

[0033] A damper 23, designed as a rotary damper, is inserted into a recess 18 of the mounting piece 6. It has a gear arranged on a shaft with a toothing 23a. This toothing engages with the toothing 22b of the extension 22. Upon rotation of the rotating piece 7 about the rotation axis 20, the shaft of the damper 23 is thus rotated, with this rotation occurring against the resistance exerted by the damper.

[0034] In the exemplary embodiment, the damper 23 has a protruding tab 23b with which it is screwed to the pin 19 with a screw 25.

[0035] The engagement section 21 of the rotary piece 7 is delimited by projections 24, which protrude on both sides in directions perpendicular to the extension direction 8. These projections 24 serve to ensure a central position of the rotary piece 7 in a main section of the displacement path, as will be explained in more detail below.

[0036] In the engagement section 21 of the rotary piece 7, first and second guide tracks 21a, 21b are formed at the rear and front (relative to the pull-out direction 8), which interact with the first and second engagement elements 13, 14 of the guide rail 4 formed by the bolts, as also explained below.

[0037] In the following, in particular based on the Fig. 15-22 , explains how it works. The mounting piece 6 can be moved between an inserted position ( Fig. 15 ) and an extended position ( Fig. 20). In the inserted position, the pull-out furniture part 2 is in its fully inserted position. In the extended position of the mounting piece 6, the pull-out furniture part 2 is in its fully extended position.

[0038] The pulling out of the mounting piece 6 from the inserted position into the pulled-out position takes place in a sliding direction 8, the pushing in against the sliding direction 8.

[0039] In the inserted position of the mounting piece 6, the rotating piece 7 rests against an insertion end stop 13a of the guide rail 4, see. Fig. 15. This is formed by a section of the outer surface of the first engagement element 13 designed as a bolt. The rotating piece 7 is in the inserted rotational position relative to the mounting piece 6 with respect to the rotation about the axis of rotation 20. The first engagement element 13 designed as a bolt is retracted into the guide track 21a of the rotating piece 7 and rests with its outer surface forming the insertion end stop 13a against the wall of the rotating piece 7 delimiting the guide track 21a. If, in the inserted position of the mounting piece 6, a force directed counter to the extension direction 8 acts on the mounting piece 6, the bolt exerts a torque on the rotating piece 7 about the rotational axis 20, which torque acts counter to the extension direction. Further rotation of the rotating piece 7 counter to the extension direction is blocked. In the inserted position of the mounting piece 6, a displacement of the mounting piece 6 against the pull-out direction 8 is thus blocked.

[0040] In the extended position of the mounting piece 6, the rotating piece rests against an extension end stop 14a of the guide rail 4. This is formed by a portion of the lateral surface of the second engagement element 14, which is designed as a bolt, see. Fig. 16 . The rotating piece 7 is in the pull-out rotation position with respect to a rotation about the rotation axis 20 relative to the mounting piece 6.The second engagement element 14, designed as a bolt, is retracted into the guide track 21b of the rotating piece 7 and rests with its outer surface, forming the extension end stop 14a, against the wall of the rotating piece 7 delimiting the guide track 21b. If, in the extended position of the mounting piece 6, a force directed in the extension direction 8 acts on the mounting piece 6, the bolt exerts a torque on the rotating piece 7 about the rotation axis 20, which torque acts in the extension direction. However, further rotation of the rotating piece 7 in the extension direction is blocked. In the extended position of the mounting piece 6, displacement of the mounting piece 6 in the extension direction is thus blocked.

[0041] When the assembly piece 6 is pulled out from the insertion position in the extraction direction 8, the rotary piece 7 is rotated by the interaction of the first engagement element 13 with the guide track 21a over an initial section of the displacement path from the insertion rotation position towards a middle rotation position, cf. Fig. 15 to 17 The sequence of movements shown in Fig. 17 In the position shown, the first engagement element 13 just comes out of engagement with the rotating piece 7.

[0042] When the mounting piece 6 is further pulled out in the pull-out direction 8, the rotating piece 7 remains in this middle rotational position over a main section of the displacement path until the mounting piece 6 reaches an end section of the displacement path. Fig. 18shows the position of the mounting piece 6, in which the second engagement element 14 has already moved slightly into the guide track 21b of the rotating piece 7 and the rotating piece 7 is just striking the wall bordering the guide track 21b on the second engagement element 14. As the mounting piece 6 is further displaced in the pull-out direction 8, the second engagement element 14 moves further into the guide track 21b of the rotating piece 7, rotating the rotating piece 7 about the rotation axis 20 until the pull-out position of the mounting piece 6 is reached, cf. Fig. 20. Fig. 19 shows a position of the mounting piece 6 in a middle area of ​​the end section of the displacement path.

[0043] When inserting the mounting piece 6 from the extended position to the inserted position, the movement sequence is essentially reversed. Fig. 21shows the position of the mounting piece 6 in which the second engagement element 14 is just disengaged from the rotating piece 7. Fig. 22 shows the position of the mounting piece 22 in which the rotating piece 7 just comes into engagement with the first engagement element 13.

[0044] The projections 24 of the rotating piece 7 serve to ensure the central rotational position of the rotating piece 7 over the main section of the displacement path. These projections interact with the downwardly facing narrow sides of the side legs 10, 11 and thus prevent rotation of the rotating piece 7, apart from a play.

[0045] Over the initial section of the displacement path, the projections 24 located at the rear with respect to the extension direction 8 are disengaged from the side legs 10, 11 of the guide rail, so that when the mounting piece 6 is inserted, the rotation of the rotating piece 7 from the middle rotation position into the inserted rotation position is possible. Over the area of ​​the final section of the displacement path, the projections 24 located at the front with respect to the extension direction 8 are disengaged from the side legs 10, 11 of the guide rail 4, so that when the mounting piece 6 is pulled out, the rotation of the rotating piece 7 from the middle rotation position into the extended rotation position is possible.

[0046] By rotating the rotating piece 7 between the insertion rotation position and the extension rotation position, the displacement path over which the mounting piece 6 can be moved relative to the guide rail 4 is extended.

[0047] The rotation of the rotating piece 7 about the rotation axis 20 is dampened by the damper 23. Thus, when the extendable furniture part is extended, the deceleration of the extendable furniture part (in the area of ​​its upper end) before reaching its fully extended position is dampened. When the extendable furniture part is pushed in, the deceleration of the extendable furniture part (in the area of ​​its upper end) before reaching its fully retracted position is dampened.

[0048] In principle, it would also be conceivable and possible to rotate the rotating piece relative to the mounting piece only over the initial section of the displacement path or only over the final section of the displacement path. Rotation over both the initial section and the final section of the displacement path has the particular advantage that the rotary damper 23 dampens both the end stop during extension and the end stop during insertion.

[0049] In the exemplary embodiment, the guide tracks 21a, 21b are curved, as is preferred. This allows for adjustment of the damping force profile when extending over the final section of the displacement path and when retracting over the initial section of the displacement path.

[0050] In the exemplary embodiment, the slide track 21b has an inner end section which, in the extended rotational position of the rotating piece 7, represents an upward bulge in which the bolt forming the second engagement element lies in the extended position, cf. Fig. 20 During assembly of the device according to the invention, the rear wall part 2a with the device according to the invention mounted thereon can be suspended from the guide rail 4 in the extended position of the mounting piece 6. In this position, the rear wall part 2a can be connected to the rear wall part 2b. This ensures the correct height of the rear wall part 2a.

[0051] Various further modifications of the illustrated embodiment are conceivable and possible without departing from the scope of the invention as defined in the claims. For example, it would be conceivable and possible to design the engagement elements 13 and / or 14 of the guide rail as parts with slide tracks, for example made of plastic, which are inserted into the profile of the guide rail, which is particularly made of metal, and which interact with at least one or two bolts arranged on the rotating piece 7.

[0052] In principle, it would also be conceivable and possible to design the guide rail with a cross-section other than U-shaped, for example V-shaped.

[0053] The damper 23 could also be secured in the mounting piece 6 in another way, for example, by snapping it in place, instead of by a screw 25. A safeguard against rotation could, for example, be provided by at least one rib running parallel to the axis of rotation, which engages a groove in the wall of the recess 18. The pin 19 forming the axis of rotation could be snapped into the through-opening 17. Key to the reference numbers: 1 Furniture body 22a Passage opening 2 pull-out furniture part 22b Gearing 2a Rear wall part 23 mute 2b Rear wall part 23a Gearing 3 Pull-out guide 23b tab 4 guide rail 24 projection 5 Unit 25 screw 6 Mounting piece 7 Rotating piece 8 Pull-out direction 9 recording room 10 side thighs 11 side thighs 12 Base bridge 13 first engagement element 13a Insertion end stop 14 second engagement element 14a Pull-out end stop 15 recess 16 slot 17 Passage opening 18 recess 19 Pen 20 axis of rotation 21 Intervention section 21a Slide track 21b Slide track 22 appendage

Claims

1. Device for lateral guidance of the upper end of an extendable furniture part (2), which can be extended from a position completely inserted into a furniture body (1) in an pull-out direction (8) to a position completely extended out of the furniture body (1), comprising a guide rail (4) which can be fastened to the furniture body (1) and the longitudinal extent of which is parallel to the pull-out direction (8), characterized in that the device has a rotating piece (7) which is guided by the guide rail (4) parallel to the pull-out direction (8) and which is mounted on a mounting piece (6) which can be fastened to the extendable furniture part so as to be pivotable about a horizontal axis of rotation (20) lying at right angles to the pull-out direction (8), the mounting piece (6) being movable relative to the guide rail (4) from an inserted position, which can be occupied by the mounting piece (6) in the fully inserted position of the extendable furniture part (2), in the pull-out direction (8) via a displacement movement to an extended position, which can be occupied by the extendable furniture part (2) in the fully extended position, and wherein, in the inserted position of the mounting piece (6), the rotating piece (7) bears against a insertion end stop (13a) of the guide rail (4) and assumes an inserted rotational position relative to the mounting piece (6) and, in the extended position of the mounting piece (6), bears against an extension end stop (14a) of the guide rail (4) and assumes an extended rotational position relative to the mounting piece (6), which is rotated about the axis of rotation (20) relative to the inserted rotational position.

2. Device according to claim 1, characterized in that, when the mounting piece (6) is displaced, starting from the inserted position in the pull-out direction (8) over an initial section of the displacement movement, the rotating piece (7) is rotated about the axis of rotation (20) relative to the mounting piece (6) by the interaction of the rotating piece (7) with a first engagement element (13) of the guide rail (4) and, when the mounting piece (6) is displaced over a main section of the displacement movement following the initial section, the rotational position of the rotating piece (7) about the axis of rotation (20) relative to the mounting piece (6) remains unchanged.

3. Device according to claim 2, characterized in that the rotation of the rotating piece (7) is damped by a damper (23), which is preferably designed as a rotation damper, when the mounting piece (6) is displaced against the pull-out direction (8) over the initial section of the displacement movement until the inserted position of the mounting piece (6) is reached.

4. Device according to one of claims 1 to 3, characterized in that when the mounting piece (6) is displaced in the pull-out direction (8) over an end section of the displacement movement before reaching the extended position, the rotating piece (7) is rotated about the axis of rotation (20) with respect to the mounting piece (6) by the interaction of the rotating piece (7) with a second engagement element (14) of the guide rail (4).

5. Device according to claim 4, characterized in that the rotation of the rotating piece (7) during the displacement of the mounting piece (6) in the pull-out direction (8) over the end section of the displacement movement until the extended position of the mounting piece (6) is reached is damped by a damper (23), which is preferably designed as a rotation damper.

6. Device according to claim 3 or 5, characterized in that the rotating piece has a toothing (22b) which is coaxial with the axis of rotation (20) and meshes with a toothing (23a) coupled to the damper (23).

7. Device according to one of claims 1 to 6, characterized in that the guide rail (4) has a downwardly open receiving space (9) which is bounded by side legs (10, 11) and into which an engagement section (21) of the rotating piece (7) projects.

8. Device according to claim 7, characterized in that the side legs (10, 11) project downwards from a horizontal base web (12) of the guide rail (4).

9. Device according to one of claims 1 to 8, characterized in that the insertion end stop (13a) is formed by a section of a lateral surface of a first engagement element (13) of the guide rail (4), while the first engagement element (13) is designed as a bolt and engages in a sliding track (21a) of the rotating piece (7) when the mounting piece (6) is displaced over the initial section of the displacement movement.

10. Device according to one of claims 1 to 9, characterized in that the extension end stop (14a) is formed by a section of a lateral surface of a second engagement element (14) of the guide rail (4), while the second engagement element (14) is designed as a bolt and engages in a sliding track (21b) of the rotating piece (7) when the mounting piece (6) is displaced over the end section of the displacement path.