WO2004070146A1

WO2004070146A1 - Pivoting tilting mounting

Info

Publication number: WO2004070146A1
Application number: PCT/EP2003/013331
Authority: WO
Inventors: Achim Türk
Original assignee: Siegenia-Aubi Kg
Priority date: 2003-02-05
Filing date: 2003-11-27
Publication date: 2004-08-19
Also published as: DE50311504D1; EP1590548A1; ATE430866T1; RU2005127571A; SI1590548T1; DK1590548T3; PL208795B1; EP1590548B1; PL376304A1; RU2329365C2; AU2003288183A1; DE20301816U1

Abstract

The invention relates to a pivoting tilting mounting, equipped with a positioning device (26) that is supported on an upper casement-frame limb (24) and an upper window-frame limb (22). An element (60) that defines the tilting gap is configured in the form of a selector gate and provided with a tilting gap defining section, which enables the engagement of an additional element (58) that defines the tilting gap and is configured in the form of an element (72, 74) that follows a curved trajectory. To enable the positioning device to operate on the right and left, a second selector gate (62) lies opposite the first selector gate relative to the longitudinal axis (68) of the positioning arm (28) in a longitudinally offset mirror-image position and one gate section (61a, 62a) of each selector gate (61, 62) is mounted in a rotatable manner on the positioning arm and the other gate section (61b, 62b) is mounted in a fixed manner on said arm (28). In the mounting position, the rotatable gate sections (61a, 62a) adopt an intermediate position, allowing the element (72, 74) that follows a curved trajectory to co-operate with one of the rotatably mounted gate sections (61a, 62a), when the drive-rod mounting is actuated in the direction of the tilted opening position, pivoting said section into a position that forms the selector gate (61, 62).

Description

turn-tilt fitting

The invention relates to a tilt and turn fitting according to the preamble of claim 1.

Such a tilt and turn fitting is known, for example, from EP 0 051 309 B1 (FIGS. 25 to 29 and FIGS. 55a to 56) or DE 31 20 941 C2.

In these tilt and turn fittings, drive rod means are attached to the sash frame and can be brought into different switching positions by a manual actuation means, namely a hand lever. For this purpose, a drive rod drive is attached to a wing frame leg, via which drive rods attached to the wing frame leg run longitudinally to the

Let the sash frame move. The drive rods have locking elements which interact with locking interlocks fixedly attached to the frame in a first functional position. In a second functional position, tilt readiness, the sash can be swiveled around a lower horizontal axis. The wing is held on its thigh by means of an opening device on the frame. For this purpose, the opening device is provided with an opening arm which is pivotally attached to the frame at one end and has a rotary slide connection assigned to the leaf frame at the other end. In the third operational position, this extension arm is opposite the

Thigh of the casement fixed so that the casement can be pivoted about a lateral vertical axis.

It is further provided in the known tilt and turn fittings that the sash can be converted into a functional position of gap ventilation by means of the drive rod means and a locking element, in which the sash frame is spaced from the frame by a narrow gap. For this purpose, the locking element comprises a first locking element assigned to the casement frame, which can be moved via the drive rods running on the thigh, and a second locking element assigned to the frame, which is attached to the opening arm of the opening device. One of the split tilt locking elements is designed in the manner of a switching link with a split tilt locking portion and an extension arm locking section for the engagement of the other split tilt locking element, the split tilt locking element designed in the manner of a shift link being attached to the opening arm.

The shifting gate is profiled in such a way that, in a gap opening function position that is different from the functional readiness for tipping, it secures the sash frame against complete closing in its gap opening position by interacting with the cam follower element and its other, partially open guide curve is open in its area assigned to the tilt opening position for the passage of the cam follower element is. It is also provided that the locking means for right and left usability are designed to be resettable or implementable.

A disadvantage of these known drive rod fittings is that the manual changeover to the right and left usability takes place by changing a space-consuming lever, or else the entire guide curve must be mapped in a component which is detachably attached to the extension arm and which must be replaced in each case ,

In the as yet unpublished German application 10142475.2, a tilt and turn fitting is claimed, which provides a detachable link section for use with one and the same opening device. The detachable link section can optionally form the switching link with one of the two fixed link sections. For this purpose, it is necessary to mount the corresponding link section on the extension arm.

The object of the invention is therefore to implement an opening device with a gap-tilt locking element which, with a simple construction, can be converted without manual intervention, in particular for leaves opening to the left as well as to the right.

This object is achieved in a generic tilt and turn fitting by the features of the characterizing part of claim 1. As a result of the configuration according to the invention, the night ventilation device of the generic tilt and turn fitting is oriented into the functional position when the espagnolette fitting is actuated for the first time in the direction of the tilt opening position. The night ventilation device is therefore equally suitable for left and right opening sashes with a tilt and turn fitting. This also simplifies the manufacture of the opening device, since no components for right or left wings have to be provided. This also reduces the costs incurred by the manufacturer, since the display device can be manufactured in large numbers. Warehousing is reduced for the company that carries out the assembly of the espagnolette fitting as well as for the trade. Finally, there is also an application advantage, because misalignments that occur with manual alignment are avoided.

It is particularly expedient if the cam follower element is at a parallel distance from the fixed link section in relation to the longitudinal axis of the extension arm in the mounting position of the connecting rod fitting, so that when the extension arm is displaced in the direction of its position limiting the tilting position, one of the rotatable link sections Sliding path of the curve follower element lies. The orientation of the rotatable link section can thus be effected in a very simple manner and no additional components are required.

If the rotatable link section in the assembly position with its boundary edge facing the longitudinal edge of the deployment arm is spaced apart from the latter, the overall installation space of the night ventilation device on the deployment device can be reduced. The spacing of the link section means that the cam follower element can be guided past the unused link section and the unused and unused link section remains in its original assembly position.

If each link section is rotationally inhibited on the extension arm, it can be ensured that, on the one hand, the rotatable link sections are in the desired mounting position during assembly and, on the other hand, that the rotatable link sections are not twisted as a result of unintentional circumstances, which may result in malfunctions could. In order to ensure the function of the turn-tilt fitting in each switching position, it is provided that the link sections are rotationally limited in the position forming the switching link. This prevents further rotation of the link sections beyond the desired position forming the shift link.

This can be done in that the rotatable link sections have a stop which engages in a recess in the opening arm.

For simple manufacture, it is provided that the recess on the extension arm is open at the edge and has a radius with respect to the axis of rotation of the link section.

In order to increase the guidance through the link section, it is also provided that the rotatable link sections are essentially L-shaped.

Further advantageous configurations result from the figures. Show it:

1 is a tilt and turn window in the tilt position,

2 is a partial view of the opening device in a view from below,

3a to 3g, the different switching positions of the split tilt locking elements,

Fig. 4 is a side view of the extension arm with the switching scenes and

Fig. 5 is a plan view of the extension arm with an elastic element attached thereto and

Fig. 6 shows another embodiment of a rotation limit of the rotatable backdrop section.

In Fig. 1 the frame of the tilt and turn window is generally designated 10 and the sash frame mounted therein with 12. The sash frame 12 is rotatable about an axis of rotation 14 and tiltable about a tilt axis 16. In the lower right Wing corner is provided at 18 a corner bearing, which allows both a tilt about the tilt axis 16, and thus a rotation about the axis of rotation 14. A tilt bearing is provided at 20 in the lower left wing corner, which is closed when tilted and can be released for the purpose of rotating the wing frame 12 about the axis of rotation 14. An opening device 26 is provided between the upper frame leg 22 and the upper casement leg 24. This opening device 26 comprises an opening arm 28 which is rotatably mounted in a pivot bearing 30 on the frame 10 about the axis of rotation 14 and is rotatably and displaceably guided with its other end in a pivoting slide guide 32 on the upper casement leg 24.

The opening device 26 further comprises an additional link 34, which is connected in an articulated manner to the opening arm 28 by means of a connecting bolt 36 and is connected in an articulated manner to the cuff rail 40, which is laid in the rebate space of the upper casement leg 24 and arranged with one below it, by means of a connecting pin 38 Drive rod 56 forms a structural unit.

On the vertical wing frame leg 46 remote from the axis of rotation, a faceplate drive rod assembly is arranged, the drive rod of which is equipped with a locking element 48 for interacting - with a counter-locking element (not shown) on the vertical frame leg 50. The drive rod means, that is to say the drive rods running on the wing frame legs 46, 24, can be displaced in the longitudinal direction of the respective wing frame leg from a manual operating handle 52.

In Fig. 1, the manual control handle 52 is shown in the tilt ready position. The manual actuation handle 52 can assume the positions indicated in the pickling sketch for FIG. 1, in position I the functional position tilt readiness, in position II the functional position tilt tilt and position III the functional position rotary shaft. In position IV, the locking lock function position, the sash frame 12 is fixed relative to the frame 10 via the locking element 48 and the counter-locking elements. In the following, the functional position I is referred to as the readiness to tilt, the functional position II as the ready-to-tilt position, the position III as the ready-to-turn position and the position IV as the locking position. In position I, the ready-to-tilt position, the drive rods (eg drive rod 56) of the upper wing frame arm 24 are shifted to the left in the drawing, and the drive rod of the vertical wing frame arm is shifted downward. In the functional position III, the ready-to-turn position, the drive rod (56) assumes a middle position with regard to its play. In this position, the deployment arm 28 of the deployment device 26 is fixed relative to the sash rebate of the upper sash leg 24 by means of a locking element, namely by engagement of a locking element 76 which can be displaced via the vertical drive rod of the sash frame leg 24 and which plunges into a locking engagement 78 arranged on the deployment arm 28. As a result, a relative movement of the extension arm 28 transversely to the fold surface, which is formed by the faceplate 40, is not possible.

In this functional position, the sash frame 12 can be pivoted about the axis 14, a vertical alignment of the sash frame 12 being ensured by fixing the distributing arm 28.

The illustration according to FIG. 1 shows a window in which the axis of rotation 14 is arranged on the right side of the frame 10 or of the casement 12.

FIG. 2 shows the opening device 26 according to FIG. 1 in a view from below, so that the drive rod 56 is visible. A split tilt locking element 58 attached to the drive rod 56 penetrates an elongated hole 54 in the faceplate 40. The split tilt locking element 58 on the connecting rod side interacts with a split tilt locking element 60 on the extension arm side in the form of a switching link 62a or 62b. The gap tilt locking element 60 is indirectly assigned to the frame 10 via the deployment arm 28, since the deployment arm 28 is fastened to this at at least one end - namely to the pivot bearing 30.

As can be seen from FIG. 2, the switching link 61 consists of two

Link sections, namely the link section 61a and the link section 61b and the switching link 62 from the link sections 62a and 62b.

The link section 61b is opposite a link section 61b which is mirror-symmetrically shaped and arranged with respect to the longitudinal center axis 68 of the extension arm 28. The curve follower element 72 visible in FIG. 2 has a second cam follower element 74 (FIG. 3) which is arranged longitudinally and longitudinally offset on the drive rod 56 but is not recognizable here.

The interaction of the cam follower element 72 and 74 with the shifting gate 61, 62 is shown in FIGS. 3a to 3g. Here, the curve sequence elements 72 and 74 are indicated; the drive rod 56 and the faceplate 40 are not shown or only hinted for better clarity.

3a shows the position of the cam follower element 72 or 74 in an assembled position of the connecting rod fitting and thus also of the opening device 26. All drive rods are therefore in a position that corresponds to the ready-to-turn position. It can easily be seen in FIGS. 3a to 3g that the first switching link 61 is opposed to the second switching link 62 of the same type with respect to the longitudinal central axis 68 of the opening arm 28 and is opposite in mirror image. One link section 61a, 62a of each switching link 61, 62 is rotatable and the other link section 61b, 62b is fixedly and non-rotatably attached to the extension arm 28. The rotatable link sections 61a, 62a are in an intermediate position in the assembly position. In this intermediate position, the link sections 61a, 62a are set in such a way that at least along the longitudinal edges of the extension arm 28 or the faceplate 40 there is a free space which is larger than the cam follower element 72 or 74. Starting from FIG In the mounting position, therefore, each cam follower element 72 or 74 is guided past the link section 61a, 62a without coming into operative connection with it.

After the espagnolette fitting is mounted on the Flügelrahmeπ 12, either the casement 12 is inserted into the frame 10 and the espagnolette fitting is operated via the manual control handle 52 or the

Espagnolette fitting is actuated without the sash frame 12 and the frame 10 being brought together.

If the sash frame 12 is inserted into the frame 10, the extension arm 28 is usually shifted during the transition from the ready-to-turn position III in the direction of the gap tilting position II as a rule by the usual push-off force of the seals lying between the sash frame 12 and the frame 10. This movement takes place almost automatically when the locking element 76 leaves the locking engagement 78 provided for this purpose.

However, it can also be provided that e.g. an elastic element 31 attached to the rotary bearing 30 is supported on the casement 12 and the force arm 28 is acted upon by force in the direction of its swiveled-out position in the tilt-ready position I (FIG. 5). The extension arm 28 is then also shifted into this position according to FIG. 3b if the sash frame 12 is not mounted in the frame 10 before the first actuation. The elastic element 31 can be supported, for example, on the rollover 13, which covers the fold area of the casement 12 in the closed state and rests on the frame 10.

It can of course also be provided that the operator carries out a corresponding slight displacement of the extension arm 28 during assembly. This is usually necessary because the opening arm 28 conceals openings for fastening elements on the faceplate 40 and the opening arm 28 has to be relocated to attach the opening device 26 anyway.

Due to the displacement of the extension arm 28, the cam follower element 72 comes into contact with the link element 61b of the switching link 61, which prevents further displacement of the extension arm 28 in the direction of its position limiting the tilting position ^", which in the exemplary embodiment according to FIGS. 3a to 3g comes to the right The displacement has the effect that the rotatable link section 61a lies on the displacement path of the cam follower element 72 and, when the cam follower element 72 is moved by the first actuation of the connecting rod fitting in the direction of the tilting open position, meets the rotatable link link section 61a and the latter moves further Displacement of the cam follower 72 pivots until it assumes the position shown in FIG. 3d.

It can easily be seen that this effect also occurs in connection with the cam follower element 74 and the shift link 62 or the pivotable link section 62a when the extension arm 28 is shifted in the left direction in the drawing and the drive rod fitting is actuated. The respectively unused link section 62a or 61a remains in its mounting position according to FIG. 3a. Due to the fact that the rotatable link section 62a or 61a in the assembly position is at a distance from it with its limiting edge 62c or 61c facing the longitudinal edge 70a, 70b of the deployment arm 28, the cam follower element 74 or 72, which is also not required for the desired opening direction, can be located on the latter guide sections 62a and 61a that are not required in each case are guided past.

The link section 61a or 61b is rotationally inhibited on the extension arm 28, so that an undesired rotation can be avoided. This can take place, for example, in that the link section 61a, 62a

Extension arm 28 engages with a rivet attachment in a bore and is caulked therein.

The bore in the extension arm 28 can have a non-circular contour, so that in conjunction with a rivet attachment matched thereto, the link sections 61a and 62a are rotationally limited in the position forming the switching link. To this end, however, it can also be provided that latching means are provided on the link section 61a, 62a, which in the position according to FIG. 3c cooperate with corresponding latching recesses of the extension arm 28. The locking means can e.g. be attached to the end regions of the rotatable and essentially L-shaped link sections 61a, 62a and consist of a stop or pin projecting in the direction of the deployment arm 28, which engages in a corresponding bore of the deployment arm 28. The necessary elastic deformation can be achieved, for example, in that the rivet attachment allows a slight inclination with respect to the extension arm 28, but e.g. by a spring washer or the like is in each case in its normal position relative to the extension arm 28.

In a particularly simple embodiment, however, the rotatable link sections 61a, 62a have a stop 71 (FIG. 4) which engages in a recess 75 in the extension arm 28. The recess 75 on the extension arm 28 is open at the edge and has - based on the axis of rotation of the

Link section 61a or 62a - a coaxial radius. As a result, the pivoting movement of the link section 61a, 62a can be limited in a simple manner and the manufacture of the individual components is simplified. When passing through the displacement path from the ready-to-turn position III to the gap-tilting position II, the cam follower element 72 abuts the link section 61a and is deflected over the edge 82 that limits the switching link 61 in the direction of displacement and is displaced in the direction 84 (FIG. 3d). By securing the rotatable link section 61a, 62a, undesired further turning is avoided. Finally, in the gap-tilting position II, the cam follower element 72 is held by a projecting nose 86 of the link section 61b, thereby preventing a further shifting of the cam follower element 72 in the direction 84.

Since the drive rod 56 is firmly connected to the cam follower element 72 via the split tilt locking element 58, the sash 12 follows the movement of the cam follower element 74 in a forced manner when the drive rod 56 moves and is therefore likewise displaced in the direction 84 towards the interior of the room.

The sash frame 12 cannot therefore be closed or opened with respect to the frame 10 over the entire displacement path along the switching link 61.

In the event of a further shift from the gap tilting position II into the tilting ready position I (according to FIG. 1), the cam follower element 72 is finally brought out of the switching link 61 and enters a laterally open area next to the link section 61a. In this switching position, the extension arm 28 can be displaced relative to the faceplate 40 or the sash rebate of the sash leg 24 (FIG. 3e) and the sash frame 12 can be pivoted about the lower horizontal axis 16.

It is easy to see that the above-described movement sequence can easily be carried out with a sash frame 12 that can be rotated about a right upright axis, but that an opening device 26 equipped exclusively with the switching link 61 for one on the left side of the frame 10 according to FIG. 1 arranged axis of rotation 14 pivotable casement 12 can not be used. For this purpose, the mirror-image and longitudinally offset link section 62, which cooperates with the cam follower 74 in the same way. In the case of a sash frame 12 of this type, the first movement of the extension arm 28 takes place toward the left side of the drawing in FIG. 3b, so that the shift gate 61 is not created and the shift gate 62 is provided by the interaction of the cam follower 74 and the rotatable gate portion 62a.

In the locking locking position IV according to FIG. 3f, the pin 76 indicated in FIG. 2 has been moved into the locking engagement 78 attached to the raising arm 28, specifically at its extreme left end.

In this switch position, the extension arm 28 is fixed relative to the faceplate 40 or to the fold of the upper casement leg 24 and the casement 12 is fixed relative to the frame 10 by engagement of the locking element 48 in a counter-locking element. Of course, in addition to the locking element 40, further locking elements can be provided on the casement 12. When the drive rod 56 is displaced via the manual actuation handle 52, it is displaced in the direction of the arrow labeled 80, the pin 76 assuming the position indicated in FIG. 2 at the right end of the locking engagement 78. In this position, the sash 12 can be pivoted about the axis of rotation 14.

If the espagnolette fitting is moved back to the ready-to-turn position III when it is actuated again, the rotatable link section 61a remains in the correct position for the opening direction and - secured by the limitation of the pivoting movement - is now always ready in the functional position upon further actuation, even then , if the aforementioned movement of the opening arm 28 in the opening direction is no longer carried out. This is also advantageous because the movement of the extension arm 28 e.g. could not be ensured after a certain period of time by deterioration in the elastic properties of the seals or the elastic element.

6 finally shows an alternative embodiment of the swivel movement limitation. In this case, on the side of the pivoting link sections 61a, 62a facing the extension arm 28, a pin acting as a stop 71 is provided on the leg lying near the longitudinal central axis 68, which engages in a recess 75 lying on the longitudinal central axis 68 in the form of a bore. The recess 75 is dimensioned significantly larger than the stop 71, so that the stop 71 can move in the bore or recess 75. The stop 71 strikes an edge of the recess 75 in one swiveling end movement, while in the second swiveling end movement it rests on the opposite edge. This embodiment has the advantage that the recess 75 can be produced very easily by punching and at the same time results in only a slight weakening of the cross section of the extension arm 28.

Reference character list

10 frames

12 casement frames

13 rollover

14 axis of rotation

16 tilt axis

18 corner bearings

20 tilting bearings

24 upper wing frame legs

26 display device

28 extension arm

30 pivot bearings

32 Swivel sliding guide

34 additional link

36 connecting bolts

38 connecting pins

40 faceplate

46 wing frame legs remote from the axis of rotation

48 locking element

50 frame legs

52 manual control handle

54 slot

56 connecting rod

58 Split tilt locking element

60 split tilt locking element

61 shift gate

61a scenery section

61b scenery section

61c boundary edge

62 shift gate

62a backdrop section

62b backdrop section

62c boundary edge

68 longitudinal central axis

70a longitudinal edge 70b long edge

71 stop

72 curve follower

74 curve follower

75 recess

76 locking element

78 bolt engagement

80 direction

82 edge

84 direction

86 nose

I readiness for tipping

II gap tilt position

III Ready for turning

IV locking position

Claims

claims

Tilt & Turn hardware for windows or doors, with in the rebate area of the

Wing frame legs arranged drive rod means which can be moved by hand in the longitudinal direction of the respective wing frame leg in order to be able to adjust the fitting successively in different functional positions, for example tilt readiness, readiness to turn, locking mechanism, with an upper frame frame of the frame (10) and an upper frame Wing frame leg of the wing frame (12), an opening device (26) is provided with an opening arm (28) which is rotatable on the frame (10) about the axis of rotation (14) and which is articulated on the upper wing frame leg (24) by means of a swivel-slide connection and which is suitable for rotating operation the upper wing frame leg (24) can be fixed essentially parallel to the latter, the wing frame (12) by means of the drive rod means (56) and through

Locking means can be secured in a split tilt or split open position against complete closing and further opening, the locking means comprising a split tilt locking element (60) attached at least indirectly to the frame (10) and a split tilt locking element (58) cooperating with it and belonging to the wing frame (12), and the gap tilt locking element (58) associated with the wing frame (12) is movable with the drive rod means (56), the drive rod means (56) being designed such that the split tilt locking elements (58, 60) between the opening device (26) on the one hand and a part ( 72, 74) on the other hand are effective, which by a on the upper wing frame leg (24) of the

Leaf frame (12) arranged drive rod (56) is movable that one of the split tilt locking elements (60) is designed in the manner of a shifting gate (61, 62) with a Spallkippfeslstellabschnl for the engagement of the other, designed in the manner of a cam follower element (72, 74) (58) that the split tilt locking element (60) designed in the manner of a switching link (61, 62) is attached to the extension arm (28), and its switching link (61, 62) is profiled in such a way that it is ready to tip over from the functional position different functional position gap tilt or gap open position the wing frame (12) by interacting with secures the cam follower element (72, 74) in its gap-open position against complete closing and its partially open shift gate (61, 62) is open in its area assigned to the tilt-open position for the passage of the cam follower element (72, 74) that the gap-tilt locking elements (58, 60 ) can be converted and converted for right and left usability, and furthermore a second cam follower element (74) is associated with the cam follower element (72) on the drive rod (56) in the longitudinal and longitudinally offset manner, and that the shifting gate (61, 62) There is at least two link sections (61a, 61b; 62a, 62b), which hold one of the cam followers (72, 74) between them in the gap opening position and are attached to the extension arm (28) independently of one another, characterized in that a first switching link (61 ) with respect to the longitudinal central axis (68) of the extension arm (28) a similar second shift gate (6 2) offset longitudinally and in mirror image, one link section (61a, 62a) of each switching link (61, 62) rotatable and the other (61b, 62b) fixed to the extension arm (28), and the rotating link sections (61a , 62a) are in an intermediate position in the assembly position, and the link follower element (72, 74) when the

Espagnolette fitting in the direction of the tilt opening position with one of the rotatably mounted link sections (61a, 62a) pivotally cooperating with the latter in a position forming the switching link (61, 62).

2. Tilt & Turn fitting according to claim 1, characterized in that the cam follower element (72, 74) in the mounting position of the connecting rod fitting to the fixed link section (61, 62b) has a - in relation to the longitudinal central axis (68) of the extension arm (28) - parallel distance , so that one of the rotatable link sections (61b, 62b) lies on the displacement path of the cam follower (72, 74) when the extension arm (28) is displaced in the direction of its position limiting the tilting position.

3. Tilt & Turn fitting according to claim 2, characterized in that the rotatable link section (61a, 62a) in the mounting position with its longitudinal edge (70a, 70b) of the extension arm (28) facing the limiting edge (61c, 62c) is spaced from it.

4. Tilt & Turn fitting according to one or more of claims 1 to 3, characterized in that each link section (61a, 62a) is rotationally inhibited on the extension arm (28).

5. Tilt and turn fitting according to one or more of claims 1 to 4, characterized in that the link portions (61a, 62a) are rotationally limited in the position forming the switching link (61, 62).

6. Tilt and turn fitting according to claim 5, characterized in that the rotatable link portions (61a, 62a) have a stop (71) which engages in a recess (75) of the extension arm (28).

7. Tilt & Turn fitting according to claim 6, characterized in that the recess (75) on the extension arm (28) is open to the edge and based on the

Axis of rotation of the link section (61a, 62a) has a radius.

8. Tilt and turn fitting according to one or more of claims 1 to 7, characterized in that the rotatable link portions (61a, 62a) are substantially L-shaped.