[Received by the International Bureau on 02 September 2011]

BRAKING DEVICE FOR THE OPENING AND CLOSING MOVEMENT OF A SLIDING PART OF A PIECE OF FURNITURE OR FIXTURE

FIELD OF THE INVENTION

The present invention relates to the field of mechanisms for actuating sliding parts of pieces of furniture or fixtures, such as, for example, furniture doors, wardrobes, walk-in closet doors or drawers. In particular, the present invention relates to a braking device of the opening or closing movement of a sliding part of a piece of furniture or fixture. The invention further relates to a piece of furniture comprising a braking device according to the present invention.

STATE OF THE ART

It is widely common the use of pieces of furniture and fixtures provided with sliding parts between a closing position and an opening position, such as, for example, wardrobe doors or walk-in closet doors. Normally, each of these sliding parts is actuated by the use of one or more trolleys fixed to the part itself and provided with actuating wheels. The latter allow the movement of the trolleys along guides/rails arranged on the top or bottom surface of the wardrobe or fixture according to the cases. Such a movement of the trolleys thus translates into an actuation of the sliding part.

Normally, the actuation of the sliding part is limited between two limit stop positions defined by appropriate stop members. In particular, such an actuation is clearly accompanied by the need to brake/slow down the sliding part when it approaches one of the limit stop positions. Otherwise, a collision of the sliding part against the limit stop could indeed cause damage to the latter. Furthermore, the possible stress produced in case of collision between the sliding part and the limit stops may also damage the actuating trolleys of the sliding part and in some conditions even the guides/rails on which the trolley themselves run.

In order to solve this problem, various braking devices have been developed to slow down the sliding parts in proximity of the limit stops. In most cases, such devices may slow down only one movement (opening or closing) but cannot slow down the movement in the opposite sense. Consequently, in order to slow down the sliding part both when closing and opening, two functionally opposed devices must be provided, i.e. one to slow down the closing movement and one to slow down the opening movement. Obviously, this aspect is disadvantageous both from the economic point of view and the installation point of view.

In order to solve this drawback, some braking devices have been developed which allow to slow down the sliding part during both the opening and closing movement. An example of such braking devices includes a containment box inside which two opposed braking devices are arranged, each of which adapted to brake one of the movements of the sliding part of the furniture or of the fixture with which the braking device is associated. Each braking device is of the viscous fluid type and has a hub directly meshing with a rack made integral with the containment box. Furthermore, each braking device is associated with a slider which is guided by the containment box and is associated with an end of one or more of the helical springs having the opposite end associated with the other slider. Both sliders comprise a hook, which interacts with a fixed member of the piece of furniture or the fixture to block the respective slider.

This braking device has several limits, the first of which is identified in the presence of two braking means of the viscous fluid rotation type. Indeed, while being relatively effective from the functional point of view, this solution is a critical factor from the economic point of view, given the high cost of devices of this type. Furthermore, the presence of two braking devices constitutes a constraint also in dimensional terms because it necessarily imposes a given length of the rack, i.e. of the box with which the rack is integral. With this regard, it is noted that also the position of the helical springs, intermediate between the two sliders, is a critical factor for the dimensions of the containment box because it necessarily imposes a rather considerable minimum distance between the two sliders.

It is noted that because of these dimensional constraints, determined by the number, type and operating principle of the components of the braking device, the latter is functionally not very versatile. Particularly, in the case of wardrobe doors, it is noted that such a device may be used for actuating doors having a longitudinal size (i.e. the size measured according to the direction of actuation) which remains comprised in a very limited range. In other words, the longitudinal size of the braking device greatly limits the number of possible applications of the device itself. SUMMARY

On the basis of these considerations, it is a main task of the present invention to provide a braking device for the opening and closing movement of a sliding part of a piece of furniture or fixture which allows to solve the above-mentioned drawbacks.

Within the scope of this task, it is a first object of the present invention to provide a braking device which is made with a relatively low number of components, which are easy to assemble.

Another object of the present invention is to provide a braking device which is functionally versatile, i.e. can be used for a high number of applications.

A not last object of the present invention is to provide a braking device which is reliable and easy to make at competitive costs.

This task and these objects are reached by a braking device for the opening and closing movement of a sliding part of a piece of furniture or fixture according to claim 1. In particular, the braking device according to the invention comprises:

- a containment box connectable to the sliding part;

- first and second sliders, comprising a first sliding body and a second sliding body, respectively, sliding within the box along a sliding direction, said first slider and said second slider comprising a first locking/unlocking member and a second locking/unlocking member, respectively, outside the containment box.

The device according to the invention further comprises a rack integral with the first slider and a rotating braking member housed in a first seat defined by the second slider, such a rotating braking member comprises a pinion portion engaged with the rack. The braking device also comprises at least a first constant- intensity spring operatively connecting the first slider to the second slider.

The braking device according to the invention comprises an advantageously low number of components which increase its reliability while limiting manufacturing costs at the same time. In particular, it is noted that unlike traditional solutions, the mechanism advantageously contemplates a single rotating braking member in viscous fluid. Furthermore, the device is particularly compact and thus extremely versatile from the functional point of view. It is noted, for example, that a device according to the invention being of longitudinal extension of approximately 340 mm may be used to actuate both doors with longitudinal extensions greater than 800 mm, thus very big, and doors of approximately 350 mm in size, thus relatively small. The range of possible applications is thus advantageously wide.

LIST OF FIGURES

Further features and advantages will be apparent in the following description of non-limitative examples of the braking device according to the present invention illustrated by way of non-limiting example only in the accompanying drawings, in which:

- figure 1 is a first exploded view from a first view point of a braking device according to the present invention;

- - figure 2 is a first perspective view of the device in figure 1 ;

- figure 3 is a second exploded view of a second view point of the device in figure 1 ;

- - figure 4 is a second perspective view of the device in figure 1 ;

- figure 5 is a view of a door of a piece of furniture, in a closing position, to which the braking device according to the invention is applied;

- figure 6 is a front view of the braking device associated to the door in figure 5 in a characteristic configuration of the closing position of the door itself;

- figure 7 is a view of the door of the piece of furniture in figure 5 during the transition of the same from a closing position to an opening position;

- figure 8 is a front view of the braking device associated to the door in figure 7 in a characteristic configuration of the position of the door in figure 7;

- figure 9 is a view of the door in figure 5 in an opening position;

- figure 10 is a front view of the braking device associated to the door in figure 9 in a characteristic configuration of the closing position of the door.

The same reference numbers and letters in the figures refer to the same members or components.

DETAILED DESCRIPTION

With reference to the mentioned figures, the device 1 according to the invention may be used to brake the opening and closing movement of a sliding part of a piece of furniture or a fixture. In particular, the device 1 is particularly suitable for braking/damping the opening and closing movement of a door of a piece of furniture or of a door of a walk-in closet. In this description reference will be made, for the sake of simplicity of the description only, to a door (indicated by reference 9) of a wardrobe or piece of furniture (indicated by reference 8), but the considerations which follow also apply to other applications as those indicated above and for other functionally equivalent applications.

Figures 1 and 3 are respectively an exploded view related to a possible embodiment of the device 1 according to the invention which comprises a containment box 5 integrally connectable to a box 9. The containment box 5 defines a longitudinal seat in which a first 10 and a second slider 20 are accommodated. Such sliders 10, 20 may slide inside the containment box along a direction X, hereinafter indicated as "sliding direction X". Each of the two sliders 10, 20 comprises a locking/unlocking member 1 1 , 21 which is operatively arranged outside the box itself (see figures 2 and 4) to be engaged/disengaged with/from a first striker 91 , 92 integral with the piece of furniture 8 with which the door 9 is associated (see figures 5, 7 and 9).

The braking device 1 according to the invention comprises a rack 15 integral with the first slider 10 and a braking member 18 integral with the second slider 20. Such a braking member 18 is of the viscous fluid rotation type and comprises a pinion portion 18' which is strictly engaged with the rack 15 both when the sliders 10, 20 move reciprocally towards and away from one another. Furthermore, according to the invention, the device 1 comprises at least one first constant- intensity spring 71 which operatively connects the two sliders 10, 20.

The exploded view in figure 1 allows to observe in detail a first embodiment of the device according to the invention. The containment box 5 comprises a first body 51 and a second body 52 connected to the first body 51 through first connecting means 59, preferably of the screw-type. The bodies 51 , 52 are developed according to a longitudinal direction coinciding with the sliding direction X. The second body 52 is intended to be integrally connected to the door 9 to be actuated so as to make the containment box 5 equally integral with the door 9. The first body 51 comprises a first surface 61 in front of the second body 52 and a second surface 62 (visible in figure 3) which is developed from the first surface 61 in direction of the lid 52. In particular, the second surface 62 is developed so as to define with the lid 52 a longitudinal opening 4 (in figure 4) which allows the sliding of the two sliders 10, 20. The first body 51 further comprises two reciprocally opposite sides 64, 64' which are developed in a direction orthogonal to the longitudinal direction X along which the two bodies 51 , 52 are developed.

With reference in particular to the exploded view in figure 3, the first slider 10 comprises a first sliding body 41 which is integral with the rack 15. The first locking/unlocking member 1 1 is coupled to the first sliding body 41 by means of first coupling means which define a first rotation axis X1 for the same first member 1 1 with respect to the first sliding body 41 . In the illustrated solution, such first coupling means are defined by a peg-shaped portion 81 of the first locking/unlocking member 1 1 and a seat 81 ' defined by the first sliding body 41 in which the peg-shaped portion 81 is inserted.

The first locking/unlocking member 1 1 comprises a first shaped portion 13 adapted to be coupled/uncoupled to a first striker 91 integral with the piece of furniture 8 with which the door 9 is associated. The first locking/unlocking member 1 1 further comprises a first guiding pin 31 sliding within a guiding groove 3 defined on the outer side of the second surface 62 of the main body 51 of the containment box 5. Such a guiding groove 3 (visible in figure 3) comprises a straight central section 3' and two end curved sections 3", 3"' which are developed from the straight section 3' so as to be reciprocally opposite. As explained in greater detail below, the sliding of the first guiding pin 31 in the straight section 3' is characteristic of a locking condition of the first member 1 1 to the first striker 91 , i.e. a locking condition of the first slider 10 to the piece of furniture 8. The passage of the first guiding pin 31 from the central section 3' to a first end 3" determines instead the unlocking of the first member 1 1 , i.e. the unlocking of the first slider 10 from the piece of furniture 8.

The second slider 20 comprises a second sliding body 42 which defines a first seat 25 in which the braking member 18 is housed. Such a first seat 25 comprises an opening 19 through which the pinion portion 18' of the braking member 18 protrudes, while a main portion 18" of the same, which contains viscous fluid, remains housed within the first seat 25. Such a main portion 18" has a crown gear 16 (on the other surface) arranged to be engaged/disengaged to/from a toothed portion 16" defined on the inner surface of the first seat 25. With this regard, the first seat 25 and the opening 19 are defined so as to allow the braking member 18 to move by oscillating between a meshing position and a non-meshing position. In particular, in the meshing position, the main portion 18" of the braking member 18 is integral with the second slider 20 and thus the pinion portion 18' actually exerts a braking action. On the contrary, in the non-meshing position, the main portion 18" turns along with the pinion portion 18' which does not exert a braking action as a consequence. It is noted that appropriate stop means 26 are provided in order to maintain the braking member 18 in the first seat 25.

The second locking/unlocking member 21 is coupled to the second sliding body 41 by means of second coupling means which define a second rotation axis X2 essentially parallel to the above-indicated first axis X1. In the illustrated case in point, the structure of the second locking/unlocking member 21 is substantially equivalent to that of the first locking/unlocking member 11. Therefore, the second coupling means are equivalent to the above-described first coupling means and comprise a second peg-shaped portion 82 of the second locking/unlocking member 21 and a seat 82' defined by the second sliding body 42 in which such a second peg-shaped portion 82 is inserted.

Similarly to the first member 11 , the second locking/unlocking member 21 comprises a second shaped portion 23 adapted to be coupled/uncoupled to/from a second striker 92 integral with the piece of furniture 8 with which the door 9 is associated. The second locking/unlocking member 21 comprises a second guiding pin 32 sliding inside the above-defined guiding groove 3. Similarly as provided for the first pin 31 of the first locking/unlocking member 11 , the sliding of the second pin 32 in the straight section 3' is characteristic of a locking condition of the second member 21 , i.e. a locking condition of the second slider 20 to the piece of furniture 8. The passage of the second guiding pin 32 from the central section 3' to the second end section 3"' determines a rotation of the second member 21 about the second rotational axis X2, i.e. the unlocking of the second slider 20 from the piece of furniture 8.

With reference to figure 4, it is noted that the first peg-shaped portion 81 and the second peg-shaped portion 82 of the first and said coupling means, respectively, may slide along the sliding direction X through the longitudinal opening 4 defined by the containment box 5. In essence, precisely through such an opening 4, the locking/unlocking member 1 1 , 21 can slide integrally with the two sliders 10, 20 remaining in all cases within the containment box 5 itself.

The second sliding body 42 of the second slider 20 comprises a second seat 35 in which a first constant-intensity spring 71 is housed. More precisely, the first spring 71 is formed by a foil made of metallic material, preferably steel, of constant section (twisted into a spiral), a portion of which protrudes from the second seat 35 to be connected with a connecting end 77 to the first sliding body 41 of the first slider 10. When the two sliders 10, 20 move reciprocally away, the first spring 71 is charged with elastic energy because the end 71 remains integral with the first slider 10. During the reciprocal distancing of the two sliders 10, 20 the first spring 71 is extended in the sliding direction X outside the second seat 35 in a position above the second sliding body 42 of the second slider 20 (see figure 3) to be connected to the connecting end 77 in a position above the first sliding body 41 . It is noted that the use of a constant-intensity spring like the one illustrated and described above makes the device 1 particularly reliable from the functional point of view and also extremely compact.

According to an alternative embodiment (not shown), the second seat 35 could be defined by the first slider 10. In this case, the connecting end of the spring would remain connected to the second sliding body 42 of the second slider 20.

With reference again to figures 1 and 3, it is noted that the second seat 35 is preferably arranged between the first seat 25 for housing the braking member 18 and the second seat 82' for the second peg-shaped portion 82 by means of which the second locking/unlocking member 21 is connected to the second sliding body 42. In general, according to the invention, the second seat 35 is defined so that the first seat 25 is in an intermediate position (evaluated along the sliding direction X) between the first sliding body 41 of the first slider 10 and the second seat 35. This arrangement allows to advantageously contain the longitudinal dimension of the containment box 5 since the sliders 10, 20 may reach an extremely close position when the first spring 71 is not loaded as will be apparent in the course of the description. According to the embodiment illustrated in the figures, the second sliding body 42 advantageously also comprises a third seat 36 in which a second constant- intensity spring 72 is housed structurally identical to the first spring 71. The use of two springs 71 , 72 is particularly advantageous as it allows to contain the overall dimensions of the braking device 1. Indeed, with the total required force being equal, the transversal and longitudinal dimensions of the two springs 71 , 72 can be reduced in the case in which the use of one spring only is provided.

With reference, in particular, to the exploded view in figure 1 , it is noted that a connecting end 77' of the second spring 72 is connected to the first sliding body 41 of the first slider 10 in a position adjacent to the above-indicated connecting end 77 of the first spring 71. The connection of the connecting ends 77, 77' of the springs 71 , 72 can be made by means of any fastening member 73 suited to the purpose.

With reference to figures 3 and 4, the first sliding body 41 of the first slider 10 comprises a first resting portion 46 intended to rest on the inner side of the second surface 62 of the first body 51. In particular, the expression "inner side" indicates the side of the second surface 63 facing the inner volume of the containment box 5. The first sliding body 41 also comprises a first guiding portion 47, which emerges from the containment box 5 in a position adjacent to the outer side of the second surface 62 of the main body 51 , as shown in figure 4.

Such a first guiding portion 47 increases the movement stability of the first sliding body 41 of the first slider 10, thus allowing it to maintain a portion essentially vertical with respect to the second surface 62 thus preventing it from tipping or in all cases reducing the instability which could derive from the presence of the longitudinal opening 4. The first sliding body 41 indeed rests with the first resting portion 46 on the inner side of the second surface 62 and by effect of the first guiding portion 47 rests stably adjacent to the edge 62' of the second surface 62 of the main body 51. Such an edge 62' substantially guides the sliding in longitudinal direction X of the first sliding body 41.

With reference again to figures 3 and 4, the second sliding body 42 of the second slider 20 comprises a second resting portion 46' intended to rest on the upper side of the second surface 62 of the main body 51 of the containment box 5 in manner similar to that provided for the first slider 10. The second sliding body 42 also comprises a second guiding portion 47' (indicated in figure 4), which emerges outside the containment box 5 in a position adjacent to the outer side of the second surface 62.

The second resting portion 46' and the second guiding surface 47' allow a stabile sliding of the second sliding body 42 inside the containment body 5 similar to that obtained by the first resting portion 46 and by the first guiding portion 47 for the first sliding body 41 of the first slider 10.

The operation of the braking device 1 according to the invention is described below with reference in particular to figures from 5 to 10. In particular, a possible application of the braking device 1 to a sliding door 9 of a piece of furniture 8 is described. With reference to figures 5, 7 and 9, the door 9 is actuated by means of a pair of trolleys 85 which are provided with actuating wheels sliding on longitudinal rails 82 fixed to the top of the piece of furniture 8. The trolleys 85 allow the actuation of the door 9 between a closing position, shown in figure 5, and an opening position, shown in figure 9.

The braking device 1 according to the invention is connected to the door 9 in an intermediate position between the two trolleys 85. A first striker 91 in the form of a peg is located in a first longitudinal position adjacent to the rails 92 for interacting with the first locking/unlocking member 1 1 of the first slider 10. A second striker 92 in the form of a peg is arranged in a second longitudinal position distanced from the first striker 91 by a predetermined longitudinal length L.

With reference to figures 5 and 6, in the closing position, the second peg-shaped striker 92 is inserted in the second shaped portion 23 of the second locking/unlocking member 21 of the second slider 20 so as to lock the slider 29 itself to the piece of furniture 8. Figure 6 allows to observe the position assumed by the various internal components of the containment box 5 of the braking device 1 in the closing position. As shown in this configuration, the two sliders 10, 20 are in a position close to the first side 64 of the box 5 and at an extremely short distance with respect to the longitudinal extension L1 of the containment box 5. Such a close position may be advantageously reached by virtue of the position assumed by the springs 71 ,72 with respect to the sliders 10,20 which does not limits its reciprocal approach. It is indeed noted that in the closing position the pinion portion 18' of the braking member 18 meshes with the rack 15 in a position substantially adjacent to the first sliding body 41 of the first slider 10.

As a consequence of the position of the sliders 10, 20, it is noted that the constant- intensity springs 71 ,72 are in a substantially resting condition. Furthermore, the first guiding pin 31 of the first locking/unlocking member 1 1 is inserted in the first curved end section 3' of the guiding groove 3. This in fact make the first slider 10 integral with the containment box 5. The second pin 32 of the second locking/unlocking member 21 is instead inserted in the straight section 3' of the same guiding groove 3. Such a condition in fact makes the containment box 5 (and thus the first slider 10) free to slide with respect to the second slider 20, which is locked instead by the second striker 92 to the piece of furniture 8.

As a result of an action carried out on the door, indicated by arrow F1 in figure 5, the containment box 5 (integral with the door 9) and the first slider 10 (integral with the containment box 5) sliding in the opening direction (indicated by reference V1 ) of the door 9, while the second slider 20 remains locked by effect of the second striker 92. This opening translation movement V1 determines a distancing between the two sliders 10, 20 and consequently a loading of the springs 71 , 72 the ends 77, 77' of which are connected to the first sliding body 41 of the first slider 10. It is noted that during such a translation movement the second guiding pin 32 remains static with respect to the piece of furniture 8, while the straight sector 3' of the guiding groove 3 slides with respect to the second pin 32.

The loading of the springs 71 ,72 is completed when following the sliding of the containment box 5, the second pin 32 integrates with the second end section 3"' of the groove 3, the shape of which determines a movement of the second pin 32 which translates into a rotation of the second locking/unlocking member 21 about the second rotation axis X2. Such a rotation unlocks the shaped second part 23 of the second locking/unlocking member 21 from the second striker 92, thus releasing the second slider 20 from the piece of furniture 8.

Figures 7 and 8 illustrate the braking device 1 after the second slider 20 has been released from the piece of furniture 8. With reference, in particular, to figure 8 in this second configuration the two sliders 10, 20 are both restrained to the containment box 5 and have the maximum reachable reciprocal distance.

This condition is reached by effect of the position assumed by the guiding pins 31 , 32 of the locking/unlocking members 1 1 , 21 of the two sliders 10, 20. Indeed, unlike the condition in figure 6, in this case, the second pin 32 of the second locking/unlocking member 21 is inserted in the second end section 3"' so as to make the second slider 20 integral with the containment box 5, thus preventing mutual translations between the two sliders 10, 20.

It is finally noted that in such a configuration, the pinion portion 18' of the braking member 18 meshes with the rack 15 in proximity of the end part of the same, i.e. at the maximum distance from the first sliding body 41 of the first slider 40. It is noted that the springs 71 ,72 of the braking device 1 are both loaded to the maximum.

The configuration illustrated in figures 7 and 8 is maintained until after the translation of the door 9, and thus with the approaching to the opening position, the first peg-shaped striker 91 does not engage the first shaped part 13 of the first locking/unlocking member 1 1 of the first slider 10. The occurrence of this event is accompanied by a rotation about the first axis X1 of the first locking/unlocking member 1 after which the first guiding peg 31 passes from the first end section 3" to the straight central section 3' of the guiding groove 3. This condition determines a second translation of the containment box 5 (integral with the door 9) and the second slider 20 (in this case integral with the box 5) with respect to the first slider 10 which remains locked to the piece of furniture 8. Such a second translation is accompanied by the elastic recall action of the springs 71 , 72 which release the previously stored kinetic energy.

It is noted that during the initial step of this second translation the pinion part 18' of the braking member 18 remains in all cases engaged in the rack 15. This determines a relative movement (indicated by V2) of the first seat 25 with respect to the main portion 18" of the braking member 18 contained in the same first seat 25. Such a relative movement V2 takes the crown gear 16 of the main portion 18" to mesh with the toothed portion 16" defined on the inner surface of the first seat 25. In this manner, the meshing position is reached and the pinion portion 18' may exert a braking action during the relative movement of the box 5 and the second slider 20 with respect to the first slider 10. Such a braking action is translated into a slowing down of the opening movement of the door 9 in proximity of the completion of the movement itself.

At the end of the opening, the braking device 1 assumes the configuration shown in figures 9 and 10. It is noted that the two sliders 10, 20 assume a minimum distance again similarly to the relative configuration in figures 5 and 6. In this case, however, the two sliders 10, 20 assume a position inside the containment box 5 close to the second side 64' of the first body 51 .

The operation of the device during the closing step of the door 9 (i.e. the passage from the configuration in figure 9 to that in figure 5) is essentially similar to that described above related to the opening. The closing of the door 9 occurs by exerting, for example, a force in the direction indicated by arrow F2 in figure 9. The first slider 10 is locked to the piece of furniture 8 by means of the first striker 91 which improves the movement thereof by interacting with the first locking/unlocking member 1 1 . After the action F2 on the door 9, the containment box 5 and the second slider 20 move with respect to the first slider 10, loading the springs 71 , 72 until the configuration related to figures 7 and 8 in which both sliders 10, 20 are integral with the box 5 is reached. It is noted that during the loading step of the springs 71 , 72 the pinion portion 18' meshes with the rack 15, while the crown 16 of the main portion 18" is disengaged from the toothed portion 16" of the first seat 25. Consequently, during this step, the pinion portion 18' does not exert any braking action.

When the second locking/unlocking member 21 engages with the second striker 92, then the second slider 20 is locked onto the piece of furniture 8, while the second containment box 5 and the first slider 10 integral therewith move under the bias of the springs 71 , 72 and under the braking action of the member 18. During this latter step, indeed, the crown gear 16 of the main portion 18" returns to engaging the toothed portion 16' defined in the first seat 25. In this manner, the closing movement of the door 9 in its terminal end is slowed down and the braking device 1 returns to the configuration shown in figures 1 and 2.

The technical solutions allow to fully fulfill the predetermined tasks and objects. In particular, the device according to the present invention is extremely compact and formed by a low number of components which are easy to assemble to one another. The braking device according to the invention is also reliable and functionally very versatile by virtue of the limited longitudinal dimension which allows the use thereof in a wide number of applications.

The braking device thus devised is susceptible to a number of changes and variants all within the scope of the inventive concept; furthermore, all details may be replaced by other technically equivalent ones.

In practice, any material as well as size or contingent shape may be used according to the needs and the state of the art.