WO2000036885A2

WO2000036885A2 - Device for lock-fixing an apparatus mounted in a rack

Info

Publication number: WO2000036885A2
Application number: PCT/FR1999/003102
Authority: WO
Inventors: Jean-Marie Goy; Xavier Bibes; Pascal Capdepuy
Original assignee: Thomson Csf Sextant; Goy Jean Marie; Xavier Bibes; Pascal Capdepuy
Priority date: 1998-12-11
Filing date: 1999-12-10
Publication date: 2000-06-22
Also published as: AU4519600A; FR2787282B1; FR2787282A1

Abstract

The invention concerns the fixing of appliances in racks using lock-fixing. The invention is characterised in that a device for fixing an apparatus (2) in a rack (1) comprises two fixing elements (5, 6) one of which is displaced by operating a handle (11), so as to co-operate with the other fixing element for fixing the apparatus (2) in the rack (1). The invention is further characterised in that locking means (12) located outside the rack (1), act on the handle (11) to lock it in the position wherein the two fixing elements (5, 6) co-operate to fix the apparatus (2). The invention is useful in particular for so-called onboard appliances, mounted for example in aeroplanes, tanks and the like.

Description

DEVICE FOR LOCKING A DEVICE

RIDE IN A RACK

The present invention relates to the fixing of devices in racks, in particular of radio or electronic devices, using a fixing of the "locking" type. It applies particularly advantageously in the case of so-called "on-board" devices, mounted for example in planes, tanks, etc.

Racks are frames in which devices can be placed either alone or side by side and / or stacked during operation. The rear of each of these devices generally includes one or more connectors, electrical or otherwise, to which correspond connectors arranged in the bottom of a space allocated to each device in the rack. These connectors mounted on the rack are connected, behind the rack, to each other or to other equipment; pushing a device into the space allocated to it has the effect of establishing the connections, electrical for example, necessary for its operation.

The advantage of placing devices in racks lies in particular in the speed and ease of their installation. It is therefore advantageous to keep these devices fixed to their operating position in the racks, using so-called "locking" systems which are simple and quick to operate, both for installing these devices in the rack and for removing them. of this rack. The operating position constitutes a so-called locked position, and the extraction of a device is obtained by an unlocking operation.

It is thus possible very quickly, either simply to add a useful device to the operation, or to intervene on a device to repair it or to replace it by another having another characteristic, which justifies the use of 'a rack system even for a single device.

There are devices placed in racks in many fields of activity, laboratories, industrial sites, control room, etc., for which locking fastening devices are in common use and are generally satisfactory. But in other cases, in particular those where the racks are "on-board", that is to say mounted for example on planes, or tanks or helicopters, the use of these locking fastening devices poses many problems. In the case of an airplane, for example, the operating conditions of the on-board equipment are particularly difficult. The devices can be subjected in particular to vibrations and / or to significant accelerations and decelerations, which require reinforcing the means used to fix them. But the problem is particularly difficult, because it is not enough for example to oversize the parts because one increases their inertia and one thus makes them more fragile with respect to vibrations.

Locking fastening devices are most often based on the following operation: on the one hand, the fastening position in the rack of the device corresponds to a position in which two fastening elements (one of which is integral with the rack and the other of the device), are pressed against each other and blocked by one another; on the other hand, a locking device, generally operating using a spring, locks this position by preventing any movement of these fixing elements, which achieves the fixing of the device in the rack. When they relate to on-board type equipment, these locking type fixing devices are often complicated, difficult to install, difficult to maneuver because impractical, and do not have a sufficient level of reliability (for example, it is frequent that springs break due to vibrations). These devices also pose problems for their manufacture, which requires producing complex shapes with great precision and therefore of high cost.

In fact at present, particularly for on-board equipment, this problem of fixing devices in racks using locking fastening devices is so serious that certain manufacturers and installers fix these devices in racks (in the case in particular of racks mounted in dashboards) using screws and nuts, and abandon the advantage of rapid installation and extraction, to favor secure fixing.

The present invention relates to a fixing device of the locking type, simple to manufacture and to assemble, making it possible to fix an appliance. in a rack quickly and securely, and to extract it easily, and applicable to difficult cases as encountered in airplanes, and more generally to the case of "on-board" devices.

The invention proposes for this purpose to use two fastening elements in abutment against one another as described above, but to keep them locked against each other by a locking device disposed at the outside the rack, and which acts on a member which controls the movement of one of the fastening elements. This arrangement enables the fixing device of the invention to be produced with simpler parts, easier to maneuver and more reliable than in the prior art, taking into account in particular that the new position of the locking device allows it to use a spring having a much lower mass than in the prior art.

According to the invention, a device for fixing an appliance in a rack, comprising at least one locking means, at least one fixing means comprising a first and a second fixing elements secured respectively to the appliance and to the rack, at least one of the two fixing elements being mobile, the device occupying in the rack a so-called fixing position, making it possible to move the mobile fixing element to a so-called blocking position in which the two fixing elements cooperate to keep the device fixed to the rack, is characterized in that the movable fixing element can be moved by actuating a handle located outside the rack, and in that the locking means is mounted outside of the rack and acts on the handle so as to block it when it is in a so-called locking position which it occupies when the movable fastening element is itself in the blocking position.

The invention will be better understood and other advantages which it presents will appear on reading the description which follows, given by way of nonlimiting example with reference to the appended drawings, among which: - Figure 1 shows in a simplified manner , in a perspective view, a rack, and apparatus fixed in this rack by a locking fixing device according to the invention;

- Figure 2 shows in a perspective view, a bar partially visible in Figure 1; - Figure 3 shows in a simplified way, by a view similar to that of Figure 1, a rack and apparatus in an operating phase different from that shown in Figure 1;

- Figure 4 shows schematically in a sectional view, a locking device and a handle body shown in Figure 3;

- Figure 5 shows a simplified perspective view of the production of a spring;

- Figure 6 shows in a simplified way, in perspective, the production of a stroke limiting device;

- Figure 7 is a perspective view which illustrates how the spring and the limiter device shown in Figures 5 and 6 are assembled;

- Figure 8 is a sectional view similar to that of Figure 4, which shows in an enlarged view the elements contained in a box shown in Figure 4.

Figure 1 shows by way of nonlimiting example a rack 1, and a device 2 fixed in this rack using a locking fixing device according to the invention. In the example shown, the device 2 is an image viewing device using a liquid crystal screen, but the invention can be applied to any other device, of the electrical type or not. To facilitate the description, an opening has been made in a wall 3 of the rack 1, in order to reveal a bar 4 which is provided with the device 2, and which is hidden when the device is pushed into the rack 1.

The device 2 is shown pressed into the rack 1 in a position called "fixing" in which it is held thanks to a first and a second fixing element 5, 6; these two elements 5, 6 are arranged inside the rack 1 and are hidden by the wall 3, they are therefore shown in dotted lines in FIG. 1.

The first attachment element 5 secured to the device 2, and the second attachment element 6 is secured to the rack 1. In the nonlimiting example described, the first attachment element 5 is constituted by a hook, which forms one end of the bar 4. The second fixing element is a projecting part, for example a pin or stud 6, fixed inside the rack 1 on the wall 3 of the latter. In the nonlimiting example described, the two fixing elements constituted by the hook 5 and the stud 6 therefore have complementary forms which make it possible to secure them to one another, when the device 2 is pushed into the rack in the position where it must be fixed.

According to a characteristic of the invention, the bar 4 is secured to the device 2, by means of a rotary pivot Pt mounted along an axis 16, on one side 9 of the device 2. The axis 16 constitutes an axis of rotation about which the hook 5 can rotate to be secured to the stud 6. This situation is shown in FIG. 1 which shows that the hook 5 traps the stud 6 in a so-called "blocking" position, so that, as long as this locking position of these two elements 5, 6 is kept, pressing one against the other, the device 2 and the rack 1 remain fixed to each other.

The hook 5, the stud 6, the bar 4 and the pivoting pivot Pt, form a fixing means, to which also belongs a handle 11 located outside the rack 1; the handle 11 is carried by the bar 4 at a second end 8 of the latter opposite to that which carries the hook 5.

FIG. 2 is a perspective view of the bar 4, making it possible to better distinguish the hook 5 and the stud 6 already mentioned above with reference to FIG. 1. The bar 4 is fixed to the device 2 (not shown in Figure 2) via the rotating pivot Pt, disposed between the hook 5 and the second end 8; the rotary pivot Pt allows a rotational movement of the bar 4 about an axis 16. The stud 6 (shown in dotted lines) is integral with the rack 1 (not shown in Figure 2). The hook 5 (located in the rack 1) forms a first end of the bar 4, the second end 8 of which is located outside the rack 1, carries the handle 11 (not shown in FIG. 2). The hook 5 has an opening or housing 7 intended to contain the stud 6 when the device is pushed into the rack in its fixing position. The hook traps the stud 6 by the rotational movement of the bar 4 around the axis 16.

The hook 5 and the second end 8 of the bar 4 are therefore located on opposite sides with respect to the axis of rotation 16, and it should be noted that a first length L1, between the housing 7 and the axis of rotation 16, ie the rotary pivot Pt, is small compared to a second length L2 formed between the axis of rotation 16 and the second end 8 of the bar 4. This arrangement makes it possible to amplify at the level of the axis of rotation 16, more importantly a force applied to the second end 8 of the bar 4, with respect to a force applied at the level of the housing 7.

Referring again to Figure 1, the handle 11 cooperates with a locking device 12, and according to a characteristic of the invention, the handle 11 and the device 12 are located outside of the rack 1; in the nonlimiting example described, they are close to a front face 10 of the device 2. In fact, the bar 4 is extended enough to leave the rack 1 when the device 2 is fixed in the latter. The bar 4 thus runs along the side 9 of the device to then be bent and brought back in front of the front face 10, in order to form the handle 11. In the nonlimiting example shown, the front face 10 is bordered on its four sides by a frame 17, so that its surface is hollow relative to this frame.

The function of the locking device 12 is to lock the locking position, that is to say to keep the hook 5 and the stud 6 secured to each other. To this end, according to a characteristic of the invention, the locking device 12 acts outside of the rack 1, on the handle 11. In fact in the nonlimiting example described, the handle 11 has two parts. on the one hand, a gripping member 112 making it easier to maneuver the bar 4, and on the other hand a handle body 111 on which the locking device acts.

The bar 4 being mobile in rotation about the axis 16, the handle 11 is also mobile and by moving it produces the displacement of the hook 5. The operation of the handle 11 thus makes it possible to move the hook 5, between the position blocking in which it cooperates with the stud 6 to fix the device 2, and a so-called "non-blocked" position, in which it does not trap the stud 6, and in which therefore the stud 6 and the hook 5 are not not subject to each other.

This is obtained by moving the handle 11 between the following two positions: - one of these positions is called "locking position", it corresponds to securing the hook and the stud 5 to 6 to each other ; in the locking position, the handle 11 is close to the locking device 12; it is in this position that the handle 11 is shown in FIG. 1; - The other position of the handle 11 is called "release position", it corresponds to the non-locked position of the hook and the stud 5, 6, that is to say when the latter are not subject one to the 'other; in the release position, the handle 11 is distant from the locking device 12.

The release position of the handle 11 is therefore the position which is suitable for introducing the device 2 into the rack 1, or for extracting it from the latter.

Figure 3 shows the rack 1 and the device 2 in a view similar to that of Figure 1, but with the difference that in Figure 3 the handle 11 is shown in its so-called release position. In the nonlimiting example shown, the release position corresponds to a lowering of the handle 11, but of course this position could result from a different movement, reverse for example, by making the different elements 4, 5, 6, Pt, 11, 12 to position them symmetrically but inversely to that described above; the locking and release positions would then be reversed with respect to the examples shown.

It can be seen in FIG. 3 that with respect to FIG. 1, the handle 11 having been lowered, that is to say brought into the release position, its movement has caused a displacement of the hook 5 which is now raised and no longer traps the pin 6: device 2 and rack 1 are released from each other. The handle 11 being in the release position: the device 2 can be removed from the rack 1; it can also be inserted into it and pushed in until it occupies its fixing position, in which it is fixed by operating the handle 11 to bring it to the locking position (by lifting the handle 11 in the example shown).

It is of course possible to install on a side 9a (not visible) opposite the first side 9 of the device 2, a second fixing means (of which only a second handle 11a is visible in FIGS. 1 and 3), similar to that which has just been described, and the handle 11a of which also cooperates with a locking device 12a. In this case, it is even possible, as in the non-limiting example shown in Figures 1 and 3, to rigidly connect the two handles 11 and 11a, that is to say the two handle bodies 111 along the face before 10, by a central bar 20. This in particular facilitates simultaneous operation of the two handles 11, 11a, with one hand.

FIG. 4 partially represents the device 2 in a sectional view, made at the level of the first locking device 12 and of the handle body 111, in a plane perpendicular to that of the front face 10. The handle 11 is more precisely, the handle body 111 is in the locked position, that is to say the position raised in the example. Bar 4 is shown in dotted lines.

The locking device 12 comprises a spring 25, and a limiter 26 serving to limit the stroke of the spring. In the nonlimiting example described, the spring 25 and the limiter 26 are mounted together between the front face 10 and the frame 17. An end portion 30 of the spring 25 is thus positioned so as to be able to trap, that is to say partially enclosing the handle body 111 to block it, when the latter is brought into the locking position. It should be noted that in the nonlimiting example shown, a recess 23 produced at the front of the frame 17 makes it possible to bring the handle body 111 and therefore the handle 11 closer to the front face 10.

FIG. 5 is a perspective view showing, by way of nonlimiting example, an embodiment of the spring 25. In the example shown, the spring 25 is obtained by a first bending in the form of a square of a metal, stainless steel for example, which may have a thickness of the order of 0.3 mm; the spring effect results from this folding. A first plane 28 of the bracket is provided with holes 35 intended for fixing the spring 25. The other plane 29 of the bracket forms a leaf of spring 29.

The end of the leaf spring 29 constitutes the end part 30 mentioned above serving to trap the handle body 111. For this purpose, this end part 30 comprises a second folding called "non-return folding", by which it leaves in the direction of the first branch 28 in order to constitute a so-called "blocking" surface or wall 31, intended to block the handle body 111 in order to achieve locking. Finally in the nonlimiting example described, by a third folding, the end part 30 starts again in the direction opposite to the first branch 28 to form a surface or wall called "abutment" 32 substantially parallel to the leaf spring 29, and which is terminated by a circular section 33 which in particular facilitates the operation of the spring 25.

FIG. 6 is a perspective view showing, by way of nonlimiting example, an embodiment of the limiter 26. The limiter 26 is square-shaped, of which a first plane 27 is provided with holes 35 intended for its fixing, and the other plane 37 of which is provided to fulfill a stop function. The limiter 26 is perforated in its first and second plan 27, 37 by an opening 36; this opening 36 is intended on the one hand, to allow the passage of the leaf spring 29 (Figure 5) and partially the passage of the end portion 30, and on the other hand to prevent the passage of the abutment wall 32 (shown in Figure 5).

FIG. 7 is a perspective view which illustrates the manner in which the spring 25 and the limiter 26 are assembled, when they are fixed together on the front face 10, to constitute a locking device 12. The dimensions of the opening 36 of the limiter 26 are such that they allow the passage, in this opening 36, of the end of the spring leaf 29 carrying the locking surface 31, in the direction represented by an arrow 39; this movement of the leaf spring is possible until it brings the abutment surface 32 against an end edge 40 of the limiter 26. This makes it possible to limit the movement of the leaf spring 29 in order to avoid the latter, by too great a stroke, to reach its limit of permanent deformation. This arrangement also makes it possible, by an overflow in all directions of the end edge 40 and lateral edges 41 of the limiter 26, relative to the dimensions of the spring 25, to constitute a protection making it possible to avoid accidental unlockings.

Figure 8 is a sectional view similar to that of Figure 4, and which shows in an enlarged manner the elements contained in a box 38 of Figure 4 which contains the locking device 12, so as to represent the elements which constitute this last and the way in which they cooperate with the handle 11 and more particularly with the handle body 111.

Found in Figure 8 the frame 17 mounted on the front face 10, at the rear of which are mounted the limiter 26 and the spring 25. The leaf spring 29 is arranged just below the limiter device 26, so as to be able to penetrate in opening 36 of the latter. FIG. 8 shows an arc of a circle 45, the center of which is constituted by the rotary pivot Pt (shown in FIGS. 1, 2, and 3); this circular arc 45 represents part of the trajectory described by the handle body 111, more precisely by an end 48 of the latter furthest from the rotary pivot Pt. This trajectory 45 therefore corresponds to the displacement of the handle body 111, along an arrow 46 to be placed in the locking position, or along an arrow 47 to go to the release position.

The locking device 12 and more particularly the spring 25, are fixed so as to be arranged on this trajectory 45, so that the locking surface 31 is situated substantially at the level where the locking must take place, that is to say the locking of the handle body 111 by the locking surface 31.

Under these conditions, when the device 2 is put in place, when it is placed inside the rack 1, its handle 11 being in the release position, that is to say lowered in the example, it just push it into the bottom of the rack in abutment, then reassemble the handle 11 to the locking position: in its movement, the handle body 111 meets the spring 25 at the wall or abutment surface 32 qu 'he pushes ; this causes the spring leaf 29 to rise up, which then passes through the opening 36 of the limiter 26, until the abutment surface 32, by disappearing, escapes the end 48 of the handle body; this position of the spring is represented in FIG. 8 by a spring marked 25a; then, under the thrust of the spring leaf 29, the end portion 30 is lowered and the blocking surface 31 encloses the handle body 111, blocking it and locking it, as shown by the spring 25

This action can be promoted by giving the spring 25 and the section of the handle body 111 shapes adapted to one another, in particular complementary: for example as in the example shown in FIG. 8, a face 51 of the handle body 111, oriented towards the blocking surface 31, can be substantially parallel thereto; it is the same for an upper face 52 of the handle body 111 which can be parallel to the leaf spring 29 on which it is supported. We can thus obtain a locking and unlocking, for a difference Dp of only a few millimeters from the position of the circular section 33 of the spring 25.

This operation is the same for the two locking devices 12, 12a, if the locking fixing device of the invention comprises a fixing means 4, 5, 6, Pt to each of the sides 9, 9a of the device 2 ; it is of course in this case to ensure that the locking devices 12, 12a act well simultaneously if the two handles 11, 11 a are actuated in the same movement.

To carry out the unlocking, the end 33 of the spring 25 (or of the two springs if two locking devices 12, 12a are mounted) is raised by a few millimeters, until it stops on the limiter 26, in order to release the handle body. 111, i.e. the handle 11. It should be noted that in the case of electronic or electrical devices, provided with connectors, it is common for these connectors to be mounted with springs which require to plug them in to exert a certain force, called "plugging force"; in this case this force can cause the handle 11 to lower itself by itself when it is released.

The fact of blocking the two fastening elements 5, 6 at the level of the handle 11 as described above, in addition to facilitating assembly and manufacture by simplifying the shapes of the parts, also has the advantage of producing a blocking very effective with one or more relatively weak springs, and yet sufficient thanks to their position.

We can see in this regard in Figure 2 that in the assembly of the invention, the spring 25 has a large lever arm, because a first length L1 formed between the rotary pivot Pt and the hook 5, is much more shorter than a second length L2 formed between the rotary pivot Pt and the second end 8 of the arm 4 (end which carries the handle 11). This allows locking to be achieved with one or more springs having a much lower inertia than in the prior art, and which can therefore withstand vibrations much better.

Claims

1. Device for fixing an appliance (2) in a rack (1), comprising at least one locking means (12), at least one fixing means (4, 5, 6, Pt, 11) comprising a first and a second fastening element (5, 6) disposed inside the rack (1) and integral respectively with the device (2) and the rack (1), at least one of the two elements (5, 6 ) of fixing being mobile, the device occupying in the rack (1) a so-called fixing position in which the mobile fixing element (5) is moved to be put in a so-called locking position, position in which the two elements fasteners (5, 6) cooperate to keep the device fixed to the rack (1), characterized in that the mobile fixing element (5) can be moved by operating a handle (11) located outside the rack (1), and in that the locking means (12) is mounted outside the rack (1) and acts on the handle (11) so as to block it when it is in a so-called locking position which it occupies when the movable fastening element (5) is in the locking position.

2. Fastening device according to claim 1, characterized in that the first fastening element (5) is movable.

3. Fastening device according to one of the preceding claims, characterized in that the second fastening element (6) is fixed.

4. Fastening device according to one of the preceding claims, characterized in that when the first fastening element (5) is in the locking position, the two fastening elements (5, 6) are subject one to the 'other.

5. Fastening device according to one of claims 1 to 4, characterized in that the first fastening element (5) is carried by a bar (4) movable in rotation about an axis of rotation (16).

6. Fastening device according to claim 5, characterized in that the bar (4) is fixed to the device (2) using a pivot (Pt) disposed along the axis of rotation (16).

7. Fastening device according to one of claims 5 or 6, characterized in that the handle (11) and the first fastening element (5) are carried by the bar (4) on opposite sides with respect to the axis of rotation (16).

8. Fastening device according to claim 7, characterized in that a first length (L1) between the axis of rotation (16) and the first fastening element (5), is smaller than a second length (L2 ) formed between the axis of rotation (16) and the handle (11).

9. Fastening device according to one of the preceding claims, characterized in that the first fastening element (5) is a hook.

10. Fastening device according to one of the preceding claims, characterized in that the movement of the first fastening element (5) is obtained by a displacement of the handle (11) between a release position, in which the two elements fixing (5, 6) are free relative to each other, and the locking position in which the two fixing elements (5, 6) cooperate to fix the device (2) in the rack (1) .

11. Fastening device according to one of the preceding claims, characterized in that the locking means (12) comprises a spring (25), one end portion (30) of which is curved so as to grip the handle (11) and to block it when the latter is in the locked position.

12. Fastening device according to claim 11, characterized in that said end portion (30) of the spring (25) is disposed substantially at the locking position, on a path (46) that describes the handle (11 ) to reach this locking position, and in that said end portion (30) is formed so as to disappear under the push of the handle (11) to a point where it escapes the handle and resumes its initial position by enclosing the handle (11) to lock it.

13. Fastening device according to one of claims 11 or

12, characterized in that the locking means (12) further comprises a limiter device (26) making it possible to limit the stroke of said end part (30) of the spring (25).

14. Fastening device according to claim 13, characterized in that the limiter device (26) is placed near the spring (25), in a direction relative to the latter which corresponds to the direction of movement of said end portion (30) allowing the handle (11) to be unlocked.

15. Fastening device according to one of claims 11 or 12 or 13 or 14, characterized in that the spring (25) is formed by a folding making it possible to obtain a part (28) used for fixing the spring and a part forming a leaf spring (29).

16. Fastening device according to claim 15, characterized in that the spring effect of the spring (25) results from said folding.

17. Fastening device according to claim 16, characterized in that the leaf spring (29) is extended by said end portion (30).

18. Fastening device according to one of claims 15 or 16 or 17, characterized in that said end part (30) is provided with a so-called stop surface (32), and in that the limiter has an opening ( 36) allowing passage of the spring leaf (29) and the end portion (30) excluding the abutment surface (32).

19. Fastening device according to any one of claims 11 to 18, characterized in that the handle (11) and the end part (30) of the spring (25) have complementary shapes (30, 31, 51) allowing to favor a blocking of the handle (11)

20. A fixing device according to one of the preceding claims, characterized in that it comprises a fixing means (4, 5, 6, Pt, 11) disposed on each of the two sides (9, 9a) of the device (2), each fixing means comprising a handle (11, 11 a) cooperating with a locking means (12, 12a), the two handles (11, 11 a) being connected by a bar (20).

21. Fastening device according to one of the preceding claims, characterized in that the handles (11, 11a) are arranged in front of a front face of the device (2).

22. Fastening device according to one of the preceding claims, characterized in that the device (2) is an electronic device.

23. Fastening device according to one of the preceding claims, characterized in that the apparatus (2) is an image display device with a liquid crystal screen.