CN111719969A

CN111719969A - Tilting window and anti-collision device of scissor mechanism and tilting window equipped with anti-collision device

Info

Publication number: CN111719969A
Application number: CN202010198900.7A
Authority: CN
Inventors: 埃马纽埃尔·迪德里希·卡米尔·范帕里斯
Original assignee: Ai ManiuaierDidelixiKamierFanpalisi
Current assignee: Ai ManiuaierDidelixiKamierFanpalisi
Priority date: 2019-03-21
Filing date: 2020-03-20
Publication date: 2020-09-29
Anticipated expiration: 2040-03-20
Also published as: BE1027187A1; BE1027187B1; ES2970815T3; EP3712363B1; EP3712363C0; EP3712363A1; CN111719969B; PL3712363T3

Abstract

A scissor mechanism for holding a sash of a tilt window in an open tilt position, the scissor mechanism comprising a sash part and a long arm and a short arm, wherein the sash part and the arm are mutually rotatably connected and are rotatable relative to each other between a closed state and an open tilt position when opening and closing the scissor mechanism, in the closed state, the mutually rotatable parts are parallel or substantially parallel to each other, and in the open inclined position, the mutually rotatable parts enclose an angle, the scissors are equipped with an anti-collision device, which comprises a spring element with a cam-like part or cam, which is elastically locked in a locked position in an open inclined position of the scissors and is pushed out of its locked position against the elastic deformation resistance of the spring element when the scissors are closed.

Description

Tilting window and anti-collision device of scissor mechanism and tilting window equipped with anti-collision device

Technical Field

The invention relates to an anti-collision device for an inclined window.

Background

A tilt window is a window having a fixed frame and a sash hingeably attached to the fixed frame.

In tilting windows, the sash may hinge around an imaginary horizontal tilting axis at the bottom side of the window until a certain opening at the top, which is called the tilting position, which is used for short-term or long-term ventilation.

In order to keep the sash in its tilted position, a scissor mechanism is usually applied, which is mounted at the top between the fixed frame and the sash and limits the opening of the sash around an imaginary tilt axis to a certain open tilt position.

Such scissors mechanisms usually consist of a long arm and a short arm which are hingeably connected.

The long arm is hingeably connected by a first end to the fixed frame via a frame part and by a further second end to the sash via a sash part.

The short arm is hingeably connected by one end to the long arm in a central point between the ends of the long arm and by the other end to the sash portion.

In a closed window, the scissor mechanism is closed and hidden in a slot between the fixed frame and the sash, whereby the arms are parallel to each other.

When the window is opened at an angle, the arms rotate open, whereby the hinge on the second end of the long arm moves into the long slot hole in the sash part until abutting against the end of the long slot hole.

The scissor mechanism thus acts as a limiter which prevents the window from falling open when tilted, which is important in terms of safety. The weight of the sash helps to keep the sash open.

However, the tilt window may also have a tendency to accidentally fall out of the tilted position again to close, for example due to negative pressure caused by an accidental gust of wind.

This is why such scissors are usually provided with an anti-crash device as is standard practice. The anti-crash device is a clip which is mounted on the first end of the long arm and holds the sash with a certain resistance in the open, tilted position, but which clip must not have too much resistance so that the operation is flexible and comfortable to a certain extent without requiring too much force when it is desired to close the sash again.

However, there is a certain trend in the market for windows, which is more specifically:

the sash profile becomes thicker and thicker in the depth direction for higher thermal performance;

windows are becoming higher and higher; and the number of the first and second groups,

triple glass is increasingly used in window sashes.

Each of these trends results in the centre of gravity of the sash being closer and closer to the vertical plane passing through said imaginary tilt axis, which makes the weight of the sash less and less helpful in keeping the sash open and therefore the sash will fall closed more easily in case of gusts of wind etc.

However, providing a stronger anti-collision device as a standard practice is not a solution, since, for example, lowering a high window becomes too laborious compared to the operation.

Disclosure of Invention

The present invention relates to an impact protection device which can be applied additionally or separately and which can preferably be installed subsequently. The anti-crash device may be provided for high windows or may be applied in case of problems.

To this end, the invention relates to an anti-collision device for providing resistance against the closing of a slanted window against the collision thereof, which slanted window is held in its open slanted position by means of a scissor mechanism, characterized in that the anti-collision device comprises a resilient element and a plate-like element or other element having a side for attaching the anti-collision device to the scissor mechanism, wherein the resilient element comprises a cam-like member or cam which in its rest position protrudes from the plate-like element or other element, and wherein the resilient element has a certain resistance against pushing the cam of the resilient element out of the rest position.

The crash protection according to the invention is intended to be attached to or be part of one of the components of the scissor mechanism by means of its plate-shaped element, so that the cam of the elastic element is located in the trajectory of one of the other components of the scissor mechanism when the scissor mechanism is opened and the cam hooks behind the one of the other components of the scissor mechanism when or before the inclined position of the scissor mechanism is reached.

Since the cam of the resilient element is hooked in the open position in order to lock the scissor mechanism in this position, this creates additional resistance to the impact of the tilting window closing, since the resilient resistance of the hooked resilient element needs to be overcome first.

Preferably, the crash barrier is glued to the scissor mechanism and for this purpose, for example, a double-sided adhesive tape is provided on the plate-like portion of the crash barrier, which is covered with a removable film that needs to be removed when the crash barrier needs to be glued to the scissor mechanism.

In this way, the impact protection device can be easily mounted on existing scissor mechanisms of tilt windows or, in the case of tall windows and when it appears necessary, as an additional impact protection device.

In this way, a classic scissor mechanism can be used for both low and high windows, and in the case of a high window, a further anti-collision device can be attached to the scissor mechanism.

Preferably, the anti-collision device is mounted on the long arm, wherein the cam is in the trajectory of the rotational movement of the short arm relative to the long arm when the tilt window is obliquely opened.

Preferably, the cam is embodied as a triangle which points downwards and which in the closed state of the scissor mechanism is located immediately adjacent to and at a distance from the side edge of the short arm.

The resistance to be overcome when starting to obliquely open the oblique window is therefore limited, since the short arm contacts the oblique side of the cam at an angle when obliquely opening, which results in less force being required to push the cam from its rest position upwards into the closed state of the oblique window.

The invention also relates to a scissor mechanism provided with an anti-collision device according to the invention, and to a tilting window equipped with such a scissor mechanism.

The invention also relates to the use of an anti-collision device according to the invention for providing resistance against collision of a tilted window which is held in its open tilted position by means of a scissor mechanism.

Drawings

In order to better illustrate the characteristics of the invention, a preferred embodiment of the crash protection device of the invention, applied to a scissor mechanism of a tilting window, is described below, by way of non-limiting example, with reference to the accompanying drawings, in which:

fig. 1 shows schematically in a cross-sectional view an inclined window equipped with a scissor mechanism having an anti-collision device according to the invention;

fig. 2 shows a front view according to arrow F2 in fig. 1;

FIG. 3 shows a perspective view of the scissor mechanism indicated by F3 in FIG. 2;

figure 4 illustrates, on a larger scale, the impact protection device according to the invention indicated by F4 in figure 3;

figure 5 shows a bottom view according to arrow F5 of the crash protection device in figure 4;

FIG. 6 illustrates the impact arrestor of FIGS. 4 and 5 in an exploded view;

fig. 7 shows a cross-sectional view according to the line VII-VII in fig. 4;

FIG. 8 shows the scissor mechanism of FIG. 3, but showing the scissor mechanism in three different positions;

fig. 9 shows a partial cross-sectional view according to the line IX-IX in fig. 8; and

fig. 10 shows the partial cross-sectional view of fig. 9 in a starting position for obliquely opening the tilt window.

Detailed Description

The tilting window 1 shown in fig. 1 consists of a fixed frame 2 and a sash 3, which is hingeably attached at the bottom of the frame 2 around an imaginary horizontal tilting axis 4.

Mounted between the fixed frame 2 and the sash 3 is a scissor mechanism 5 which limits the maximum tilt angle at which the sash 3 can be tilted open, as in the case of fig. 1.

A classical scissor mechanism is shown by way of example in fig. 3.

As is evident from this fig. 3, the scissor mechanism 5 is composed in a known manner of the following components: a frame portion 6 for attachment to the fixed frame 2; a sash portion 7 for attachment to the sash 3; a long arm 8 which is rotatably connected by a first end 9, in this example by means of a double link 10, to the frame part 6, and by a further second end 11, in this example by means of a hinge pin 12 which engages in a long slot hole 13 of the sash part 7, and is rotatably and hingably connected to the sash part 7; and a short arm 14 hingeably connected by one end 15 to the long arm 8 with a hinge pin 16 between a first end and a second end of the long arm 8 and by its other end to the sash portion 7.

The rotatable connection between the long arm 8 and the frame part 6 can also be realized in other forms than a double link 10, for example directly or by means of more than two arms.

The combined sliding and hinge connection between the long arm 8 and the sash part 7 may also be realized in other ways than with the hinge pin 12 and the long slot hole 13.

Normally, the scissor mechanism 5 is always provided with a frame part 6, a sash part 7 and a long arm 8 and a short arm 14 therebetween, which is able to hinge in relation to the long arm 8 when opening and closing the tilting window 1.

The long arm 8, the short arm 14 and the sash portion 7 are rotatably connected and are collectively referred to as mutually

rotatable members

7, 8 and 14.

On the sash side, the scissor mechanism 5 may be provided with an anti-collision device, not shown here.

The invention is peculiar in that the scissor mechanism 5 is provided with an anti-crash device 18 as shown in fig. 4-7, which in this example is glued to the long arm 8 as shown in fig. 3, for providing resistance against slamming closure of the tilting window 1.

The anti-crash device comprises a plate-like element 19 with side edges 20 and a bottom side 21, which is provided with a self-adhesive layer 22 or double-sided adhesive tape in order to be able to attach the anti-crash device 18 to the scissor mechanism 5. In the uninstalled state, the glue layer may be provided with a removable film 23.

The anti-crash device 18 further comprises an elastic element 24 which is mounted next to and along the side edge 20 and which is connected to the plate-shaped element 19 and which comprises a cam or cam-like portion 25 which in its rest position projects downwards below the bottom side 21 of the plate-shaped element 19, whereby the assembly is such that the cam 25 can be pushed elastically upwards by an upward force in a direction perpendicular to the bottom side 21 of the plate-shaped element 19.

Preferably, the elastic element is made entirely of an elastic material, such as polyamide.

In the example of the figures, the elastic element 24 is made of a longitudinal elastic body 26 on which said cam 25 is mounted and which is enclosed along said side edges 20 in two seats 27 of the plate-like element 19, wherein said cam 25 is mounted between the two seats 27 and the seats 27 are such that they allow elastic stretching of the body 26 in the longitudinal direction X-X' but prevent it from rotating in the seats 27.

For this purpose, the longitudinal elastic body 26 is in this example made as a flat band, for example, and each of the seats 27 is formed by a U-shaped bracket with

legs

27a and 27b, the longitudinal elastic body 24 being enclosed between the

legs

27a and 27 b.

The

legs

27a and 27b of the U-shaped bracket 27 extend parallel or substantially parallel to the bottom side 21 of the plate-like element 19, and the opening 27c of the U-shaped bracket 27 faces the plate-like element 19.

The plate-like member 19 is made of, for example, a metallic stainless steel plate or the like, and the seat portion 27 is formed by, for example, folding the plate twice at a right angle.

The elastic element 24 can be slid laterally in the seat 27, for example along the opening 27c, and then secured against lateral removal and rotation by providing the longitudinal body 26 with an undercut or slot 28 horizontally at the location of the bracket 27 and folding at least one leg 27b of the bracket 27 into the undercut or slot 28 as shown in fig. 7.

The bracket is connected to the plate-like element 19 by means of a downward facing neck 29, said neck 29 being able to be used during mounting to align the anti-collision device 18 against the side edge 30 of the long arm 8.

In order to fix the longitudinal body 26 in the seat 27 along the longitudinal direction X-X', said longitudinal body 26 is made thinner, for example, in the portion 26a at the level of the position of the seat 27 than in the portion outside the seat 27 (i.e. in the central portion 26b and at the end portion 26c, respectively).

Preferably, the cam 25 is made in the shape of a triangle which is attached or connected by its bottom edge portion 25a to a central portion 26b of the longitudinal body 26 and which has a short side 25b and a long side 25c, said short side 25b and said long side 25c together enclosing an angle which faces away from the bottom side 21 of the plate-like element 19.

The cam 25 is mounted with its base 25a eccentric from the central portion 26b and extends from one seat 27 on the side of the long side 25c up to a distance from the other seat 27 on the side of the short side 25b, which in the example is approximately equal to half the length of the central portion 26 b.

The bottom edge portion 25a and the long side 25c enclose an angle B of between 15 ° and 20 °, preferably an angle B of about 18 °.

The bottom edge portion 25a and the short sides 25b enclose an angle a of about 70.

In the example, as shown in fig. 3, the impact protection 18 is attached to the long arm 8 with the neck 29 abutting against a side edge 30 of the long arm 8, and such that the cam 25 is hooked with its short side 25B behind a side edge 14a of the short arm 14 facing the first end 9 when the scissor 5 is opened to its maximum inclined position, wherein the cam 25 faces the first end 9 of the long arm 8 with its angle B between the bottom side 25a and the long side 25 c.

If mounted in this way, the spring element 24 extends in its longitudinal direction along the side edge 30 and, when opening and closing the scissor mechanism 5, the cam 25 is located in the trajectory of the short arm 14, which rotates about the hinge pin 16 relative to the long arm 8 when opening and closing the scissor mechanism 5, and in the closed state of the scissor mechanism 5, the cam 25 falls immediately adjacent to the opposite side edge 14b of the short arm 14 and at a lateral distance D from the opposite side edge 14b of the short arm 14, as shown in fig. 9.

The operation of the anti-crash device is very simple and is illustrated by fig. 8, which fig. 8 shows three assumed positions of the scissor mechanism 5, namely the closed position I; an open position III and a position II in between, which correspond to a closed tilting window, a tilting window which is as open as possible and an intermediate position of the tilting window, respectively.

In the closed position I, the short arm is located at a distance D from the cam 25, as shown in the corresponding bottom view of fig. 9.

When the scissor mechanism 5 is opened, the side edge 14b of the short arm 14 contacts the long side 25c of the cam 25, as shown in FIG. 10.

When opening it further, the short arm 14 pushes the cam 25 upwards, as shown in the intermediate position II in fig. 8, until when the cam 25 is hooked behind the short arm 14 by its short side 25b, as shown in the position III in fig. 8, which corresponds to the open position of fig. 3.

Thus, the opened tilted position of the scissor mechanism 5 and thus of the tilt window 1 is to some extent blocked and fixed to prevent accidental slamming shut under the influence of wind gusts or the like.

In order to close the tilting window 1 at will from its tilted position, the user must first overcome the resistance to movement of the short arm 14, which is impeded by the cam 25, and must first unlock the short arm 14, since it needs to push the cam 25 upwards along the short tilted side 25b of the cam 25 with its side edge 14 a.

This solution does not unnecessarily increase the force.

By cutting the resilient element, for example at one of the portions 26b, such that said cut portion 26b no longer has any influence on the force required for the resilient deformation of the resilient element 24, it is possible to reduce to a limited extent the force required to unlock the tilting window from its tilted position.

It should be noted that it is also conceivable to provide similar additional crash protection in other positions, for example at the level of the angle between the short arm 14 and the sash portion 7 or at the level of the angle between the long arm 8 and the sash portion 7.

Thus, it is possible to mount the anti-crash device 18 on each of the mutually

rotatable parts

7, 8 and 14, wherein the cam 25 in the open inclined position of the scissor 5 hooks behind a side edge of the other mutually

rotatable part

7, 8 or 14 and is pushed upwards by the other mutually rotatable part when closing the scissor 5.

The attachment of the anti-crash device to the scissor does not have to be made by gluing, but may also be done by clamps, screws or any other suitable means, or even the manufacture of the scissor as an integrated part of the constituent elements of the scissor may be provided, for example the plate-like element 19 is formed by one of the arms itself to which the elastic element is attached.

It should be noted that the anti-crash device 18 can also be mounted with said bottom side of the plate-like element 19 pointing upwards and the cam pointing upwards, for example when the short arm 14 is located above the long arm 8 instead of below as shown in the figures, or the plate-like element 19 can be mounted with its opposite top located below the long arm 8 or another element. Thus, the concepts of "bottom side" and "downward" may not be construed restrictively in relation to absolute directional indications.

Some features are listed again:

the longitudinal body 26 can be made thinner at the level of the seat 27 than on both sides of each bracket 27;

for example, the bottom edge 25a of the cam 25 extends for a length approximately half that of the central portion 26b of the longitudinal body 26 between the two seats 27;

the long side 25c and the bottom 25a enclose an angle B comprised between 15 ° and 20 °, preferably an angle of about 18 °, and this angle B faces said first end of the central portion 26B of the longitudinal body 26;

the short sides 25b and the bottom side 25a enclose an angle of about 70 °;

the elastic element 24 with its longitudinal body 26 and its cam 25 is made of an elastic material, such as polyamide;

the plate-like element 19 and the seat 27 are made of sheet metal material, such as stainless steel;

the cam 25 faces the first end 9 of the long arm 8 through an angle B between the base 25a and the long side 25c of the cam 25;

the tilting window comprises a fixed frame 2 and a sash 3 hingeably mounted in a tilted position at the bottom of the fixed frame 2, wherein the tilting window 1 is provided at the top with a scissor mechanism 5 mounted between the fixed frame 2 and the sash 3 and attached to the fixed frame 2 and the sash 3 by a frame part 6 and a sash part 7 of the scissor mechanism, respectively.

The invention is in no way limited to the embodiments described by way of example and shown in the drawings, but an impact protection according to the invention can be implemented in various forms and dimensions without departing from the scope of the invention.

Claims

1. An anti-crash device for providing resistance against slamming shut of a tilt window (1), the tilting window (1) is held in its open tilted position by means of a scissor mechanism (5), characterized in that the anti-collision device (18) comprises an elastic element (24) and a plate-like or other element (19), the plate-like or other element (19) has a side for attaching the anti-collision device (18) to the scissor mechanism (5), wherein the elastic element (24) comprises a cam-like member or cam (25), said cam-like member or cam in its rest position protruding from said plate-like element or other element (19), and wherein the elastic element (24) has a resistance to push the cam (25) of the elastic element (24) out of the rest position.

2. An anti-crash device according to claim 1, characterized in that said elastic element (24) is made of a longitudinal elastic body (26) on which said cam (25) is mounted and which is enclosed in two seats (27) of said plate-like element (19) which are located in extension of each other, wherein said cam (25) is mounted between the two seats (27) and said seats (27) are such that they allow elastic stretching of said body (26) in a longitudinal direction (X-X') but prevent rotation of said body (26) in said seats (27).

3. An impact protection device according to claim 2, characterized in that the longitudinal elastic body (26) is made as a flat band and that each of said seats (27) is formed by a U-shaped bracket with legs (27a, 27b), said body (26) being enclosed between said legs (27a, 27 b).

4. An impact protection device according to claim 3, characterized in that the legs (27a, 27b) of the U-shaped bracket extend parallel or substantially parallel to the side (21) of the plate-like element (19).

5. The crash protection device according to claim 3 or 4, characterized in that the longitudinal body (26) is provided with an undercut or groove (28) at the level of the bracket (27), wherein the longitudinal body (26) is fixed in the bracket (27) in a lateral direction due to the bending of at least one leg (27b) of the bracket (27) into the undercut or groove (28).

6. An anti-collision device according to any one of claims 2 to 5, characterised in that the cam (25) is mounted eccentrically from a central portion (26b) of the longitudinal body (26) between the seats (27).

7. An impact protection device according to any one of claims 2 to 6, characterized in that the cam (25) is made in the shape of a triangle extending perpendicularly to the side of the plate-like element (19) and attached to the longitudinal body (26) by its base edge (25a), and has a short side (25b) and a long side (25c), which together enclose an angle facing away from the side (21) of the plate-like element (19).

8. The crash protection device according to claim 7, characterized in that the bottom edge portion (25a) of the cam (25) extends approximately from a first end of the central portion (26b) in the longitudinal direction (X-X') of the body (26) in the longitudinal direction up to a longitudinal distance from a further second end of the central portion (26 b).

9. An impact protection device according to any one of the preceding claims, wherein said plate-like element (19) is provided with a glue layer (22) with a removable film (23).

10. The crash protection device according to one of the preceding claims, characterized in that the crash protection device (18) is intended to be mounted on a scissor mechanism having mutually rotatable parts (7, 8, 14), which mutually rotatable parts (7, 8, 14) enclose an angle with each other in an open inclined position of the scissor mechanism (5) and which mutually rotatable parts are parallel or substantially parallel to each other in a closed state of the scissor mechanism (5), and the crash protection device (18) is attached in a mounted state by means of its plate-like element or other element (19) to one of the mutually rotatable parts (7, 8, 14) in such a way that the cam (25) in an open inclined position of the scissor mechanism (5) latches in a position against the remaining mutually rotatable parts (7, 8, 14), whereby the cams (25) are pushed out of the blocking position by mutual rotation when the scissor mechanism is closed.

11. A scissor mechanism for holding a sash (3) of a tilting window (1) in a fixed frame (2) of the tilting window (1) in an open, tilted position, the scissor mechanism (5) comprising a long arm (8), a short arm (14) and a sash part (7) for attachment to the sash (3), wherein the sash part (7) and the arms (8, 14) are connected in a mutually rotatable manner and are referred to herein as mutually rotatable members (7, 8, 14) of the scissor mechanism (5), which mutually rotatable members (7, 8, 14) are rotatable relative to each other between a closed state and an open, tilted position when opening and closing the scissor mechanism (5), in which closed state the mutually rotatable members (7, 8, 14) are parallel or substantially parallel to each other, in the open inclined position, the mutually rotatable parts (7, 8, 14) enclose an angle, characterized in that the scissor mechanism (5) is equipped with an anti-collision device (18), the anti-collision device (18) comprising a spring element (24) having a cam-like part or cam (25), which is resiliently latched in a latching position in the open inclined position of the scissor mechanism (5), and which is pushed out of its latching position against the resistance of the spring element (24) against resilient deformation when the scissor mechanism (5) is closed.

12. Scissors according to claim 11, characterised in that the resilient element (24) is mounted on one of the mutually rotatable parts (7, 8, 14) of the scissors (5) such that in the catch position of the cam (25) catches in a position behind one of the remaining mutually rotatable parts (7, 8, 14), wherein the cam (25) is pushed out of its catch position by mutual rotation of the mutually rotatable parts (7, 8, 14) when the scissors (5) are closed.

13. A scissor mechanism according to claim 11 or 12, characterized in that the resilient element (24) of the anti-crash device (18) is attached on the long arm (8) in such a way that the cam (25) is located in the trajectory of the short arm (14) of the scissor mechanism (5) when the scissor mechanism (5) is open and hooks behind the short arm (14) when or before reaching the open tilt position of the scissor mechanism (5).

14. A scissor mechanism according to any one of claims 11 to 13, characterized in that the scissor mechanism is equipped with an impact protection device (18) according to any one of claims 1 to 15, wherein the plate-like or other element (19) is formed by one of the mutually rotatable components (7, 8, 14) or by such an element (19), to which the elastic element (24) is attached by means of the element (19).

15. A scissor mechanism according to claim 14, having an anti-collision device according to any one of claims 7 to 10, characterized in that in the open, tilted position of the scissor mechanism (5), the cam (25) is hooked with its short side (25b) behind one of the mutually rotatable parts (7, 8, 14) of the scissor mechanism (5).

16. Scissor mechanism according to claim 14 or 15, characterized in that the cam (25) abuts against a side edge (14b) of the mutually rotatable parts (7, 8, 14) in the closed state of the scissor mechanism (5) and is located at a lateral distance (D) from the side edge of the mutually rotatable parts behind which the cam needs to be able to hook in the open inclined position.

17. Scissor mechanism according to any of claims 11-16, characterized in that the anti-collision device (18) with a plate-like or other element (19) is glued to the scissor mechanism (5).

18. A scissor mechanism according to any one of claims 11 to 17, characterized in that the impact protection (18) constitutes an additional protection means in addition to the current impact protection between the long arm (8) and the frame part (6).

19. Use of an anti-collision device for providing a resistance against collision closing of a tilted window (1), the tilted window (1) being held in its open tilted position by means of a scissor mechanism (5), wherein the scissor mechanism (5) comprises a long arm (8), a short arm (14) and a sash part (7) for attachment to a sash (3), wherein the sash part (7) and the arms (8, 14) are connected in a mutually rotatable manner and are referred to herein as mutually rotatable members (7, 8, 14) of the scissor mechanism (5), which mutually rotatable members are rotatable relative to each other between a closed state and an open tilted position when the scissor mechanism (5) is open and closed, and an open tilted position, in which closed state the mutually rotatable members (7, 8, 14) are parallel or substantially parallel to each other, in the open inclined position, the mutually rotatable parts (7, 8, 14) enclose an angle, characterized in that the anti-crash device (18) is an anti-crash device (18) according to any one of claims 1 to 10, which has a spring element (24) with a cam-like part or cam (25), wherein the spring element (24) is attached to one of the mutually rotatable parts (7, 8, 14) such that the cam (25) is elastically blocked in a blocking position in the open inclined position of the scissor mechanism (5) and is pushed out of its blocking position against the elastic deformation resistance of the spring element (24) when the scissor mechanism (5) is closed.