Patent Description:
In the present context, a lift-up door opening device is understood to be any of the following examples:.

Various devices are known for the lifting of doors of furniture items of the different types given above. These devices are capable of balancing the weight in each position that the door assumes during opening as a result of the user's action, without the door going to occupy its position of maximum opening (or closure) when this action is interrupted.

In addition to the undoubted ergonomic advantages of not forcing the user to close the door from its maximum opening position, these devices also offer the fact of having the characteristic of perfectly balancing the weight of the door in every position. Therefore, the weight perceived by the user is practically zero, thus giving the sensation of lightness and ease of use.

Mechanisms that meet this requirement have the disadvantage of having large overall dimensions inside the storage compartment, thus occupying spaces that are useful for the effective use of an item of furniture. This is due substantially to the need to guide and keep inside their seats the elastic elements assigned to produce the energy for balancing the weight of the door.

In the prior art, these devices, in addition to having specific cases for containing the elastic elements, have further containers designed to contain the device components and therefore also the cases themselves. This inevitably leads to an increase in the overall dimension of the device, which is in contrast with the current trend of concealing the mechanics required for movement of the doors, dictated by design reasons.

<CIT> discloses a door opening and closing device includes: a main body attached to a housing; a mounting member attached to a door; an arm pivotably provided to the main body, the arm applying force to the door via the mounting member in an opening direction and/or a closing direction; a slider provided to the main body so as to be slidable in one direction; an urging means for urging the slider in the one direction; a transmission mechanism for transmitting urging force of the urging means to the arm; and a door restraint link pivotably linked to the arm at a position away from the center of pivot of the arm, pivotably linked to the mounting member, and slidably linked to the main body.

<CIT> discloses a mechanism for moving a furniture door, apt to be placed on a lateral side of the piece of furniture and to move a door by means of a system of levers, said mechanism comprising a spring unit acting on said system of levers to balance the weight force of the door during opening, wherein said spring unit is pivotally mounted and acts directly on a main or thrust lever, mounted rotating around an axis, by means of a pin housed in a first cam slot formed in the lever and in a second cam slot placed in a fixed position with respect to the lateral side of the piece of furniture.

The object of the present invention to provide a device for opening lift-up doors that eliminates the disadvantages of the mechanisms of the prior art disclosed above.

More particularly, an object of the invention is to propose such a device that has a reduced overall thickness dimension such as to occupy a minimum space inside the item of furniture, and therefore be almost hidden in the interior of the side.

A further object of the invention is to provide such a device that ensures the balancing of the weight of the door in every position, both when opening and closing, and that avoids a sudden jerk during opening and provides a cushioning effect during closure.

A further object of the invention is to provide such a device that is simple and inexpensive to manufacture and easy to assemble and mount.

Yet another object of the invention is to provide a device for opening lift-up doors that can be used in all of the types of doors previously mentioned: upward flap opening, vertical opening, pivoting opening, packet opening.

These and other objects of the invention are achieved with the features of the appended independent claim <NUM>.

Advantageous embodiments of the invention are disclosed by the dependent claims.

Substantially, the device for lift-up opening of a door of an item of furniture according to the invention comprises a container that can be attached to the frame of the furniture item, in particular to one of the sides thereof, containing in its interior a mechanism that acts, by means of an arm, articulated to the container around a fulcrum pin, directly or indirectly on the door, wherein said arm carries an eccentric pin housed in a curved profile opening formed in the container, and capable of engaging with a cam profile of a plate slidably housed in the container, under the action of at least one spring acting between said container and said plate in the opposite direction to said cam profile, said cam profile and the action of said one at least spring balancing the weight of the door in each position during opening and closure.

Further features of the invention will be made clearer by the following detailed description, referring to one of its embodiments purely by way of a non-limiting example, illustrated in the accompanying drawings, in which:.

In <FIG> and <FIG>, solely by way of example, the device according to the invention is applied to an item of furniture with a packet lift-up door, of the type shown in <FIG>, it being understood that it can be used, without substantial modifications, for the opening of doors with a different lifting mode, as shown, for example, in <FIG>.

Referring to <FIG> and <FIG>, therein is illustrated an item of furniture, denoted overall by reference numeral <NUM>, comprising a fixed frame made up of a lower wall or shelf <NUM>, an upper wall or shelf <NUM>, two side walls or sides <NUM>, one of which is removed to show the device according to the invention, denoted by reference numeral <NUM>, and a possible back wall <NUM>. The furniture item <NUM> has a door <NUM> at the front, which in the present case is divided into two half-doors, an upper half-door 6a and a lower half-door 6b. The upper half-door 6a is pivoted to the upper shelf <NUM> of the furniture item, and the two half-doors are articulated one to the other by means of a lever mechanism <NUM>, the whole substantially in itself known and therefore not described further.

The device <NUM> according to the invention, illustrated more clearly in <FIG>, serves to balance the weight of the door <NUM> in any position during the opening and closing movement, and comprises a box container <NUM> containing a mechanism that acts on the door via an arm <NUM>, articulated to the lever mechanism <NUM>, or directly to the door.

The container <NUM> is fixed to the frame of the furniture item <NUM>, in this case to a side wall or side <NUM>, and comprises two suitably shaped half-shells, substantially identical one to the other, which, for convenience only, will be called base <NUM> and cover <NUM>, between which the various components of the mechanism are housed, and to which the arm <NUM> is pivoted.

More particularly, referring to <FIG>, the arm <NUM> is mounted in such a way as to be able to rotate freely around a pin <NUM> fixed to the container <NUM>, and carries a pin <NUM> with a roller <NUM> which is housed in a curved profile opening <NUM>, formed in the container <NUM>, and which is capable of receiving the force necessary to support the door, as will be described in greater detail here below.

Referring to the blown-up view of <FIG>, between the two half-shells <NUM>, <NUM> a plate <NUM> is arranged, in the shape of a rectangular frame, having a large window <NUM>, delimited by two longer horizontal sides (with reference to the arrangement of <FIG>) <NUM>, that are slidably housed in corresponding longitudinal guides <NUM> of the container <NUM>, and by two shorter vertical sides <NUM>, <NUM>, arranged respectively at the rear and the front part of the container <NUM>, when viewed from the front part of the furniture item.

The front side <NUM> of the plate <NUM> has a thickness increasing from the top downwards, so as to determine internally a cam profile <NUM>, which delimits the window <NUM> at the front.

The pin <NUM> of the arm <NUM>, passing through the opening <NUM> of the container <NUM>, goes to interact, via the roller <NUM>, with the cam profile <NUM> formed on the plate <NUM>, as will be described in greater detail here below.

A pair of springs <NUM> are arranged in the window <NUM> of the plate <NUM>, which are housed in respective seats <NUM> formed internally to the two half-shells <NUM>, <NUM>.

The springs <NUM> act on the one hand against abutments <NUM> provided in the half-shells, at the front end of the seats <NUM>, and on the other hand against the rear side <NUM> of the plate <NUM>, by means of abutments <NUM> and devices <NUM> for regulation of the preload of the springs.

Each device <NUM> has a pair of hexagonal nuts <NUM>, appropriately distanced one from the other, arranged on an eccentric shaft <NUM> housed in a corresponding seat <NUM> provided inside the side <NUM> of the plate <NUM>, which constitutes the centre of rotation thereof. One of the faces of the nuts <NUM> is arranged against the abutment <NUM>, on the opposite side with respect to the end of the corresponding spring <NUM>. Since the faces of the hexagonal nuts are at a different distance from the eccentric shaft <NUM>, they restrain the spring <NUM> at different preloads depending on the orientation of the device <NUM> with respect to the plate <NUM>. The ends of the eccentric shaft <NUM> are housed in corresponding longitudinal slots <NUM> provided in the half-shells <NUM>, <NUM>, and have holes for rotational actuation by means of an appropriate key.

Once the orientation of the preload adjusting devices <NUM> has been selected, the springs <NUM> act from the abutments <NUM>, fixed, to the abutments <NUM> made integral with the plate <NUM> which, as mentioned, translates along the longitudinal guides <NUM> in one direction and in the other, causing the compression/distension of the springs <NUM>.

The plate <NUM>, undergoing the action of the springs <NUM>, slides along the guides <NUM> until the particular cam profile <NUM> meets the pin <NUM> of the arm <NUM> causing rotation thereof around the pin <NUM>. During the rotation of the arm <NUM>, the roller <NUM> rolls along the cam profile <NUM>, therefore the plate <NUM>, through the action of the springs <NUM> and the appropriate shape of the cam profile <NUM> imparts on the arm <NUM> a torque that varies according to the position taken up by the roller <NUM>.

The cam profile <NUM> is designed in such a way as to give perfect balancing of the door in all its positions along the arc of opening in such a way that if the action by the user is interrupted the door is balanced and does not continue its stroke until complete opening. The same takes place during the phase of closure.

<FIG> show a sequence of configurations of the device according to the invention, starting from the condition of fully closed door to that of door fully open, in which the container <NUM> of the movement mechanism is shown without the half-shell or cover <NUM> and with parts in transparency to better show the position of the various elements.

<FIG> shows the device in the condition of closed door, in which the springs <NUM> are in a compressed condition, determined by the interference of the roller <NUM> of the pin <NUM> with the lower section of the cam profile <NUM>, i.e. the thicker part of the front side <NUM> of the plate <NUM>.

Starting from this condition, a rotation of the arm <NUM> in clockwise direction, corresponding to the direction of opening of the door, produces the sliding of the roller <NUM> of the pin <NUM> along the cam profile <NUM> of the plate <NUM>, moving to the less thick section of the side <NUM>, and allowing the plate <NUM> to move to the right under the action of the springs <NUM> which tend to distend.

As mentioned, the cam profile <NUM> and the calibration of the springs <NUM> are such as to balance the weight of the door in any position it occupies during opening.

<FIG> shows the arrangement of the mechanism in a condition of partially open door, and <FIG> in the condition of fully open door, in which the springs <NUM> are in the condition of maximum distension, established by the preload devices <NUM>.

The closure of the door, starting from the condition of <FIG>, causes a rotation anticlockwise of the arm <NUM>, with a path of the roller <NUM> inverse to the previous one, until it reaches the configuration of <FIG>.

The closure of the door takes place in a damped manner, as will now be described with particular reference to <FIG> and <FIG>.

Inside the half-shells <NUM>, <NUM> opposing arcuate housings <NUM> are provided (only one can be seen in <FIG>, and partially in transparency in the others), arranged around the openings <NUM>, in which respective arcuate plates <NUM>, which reproduce the curved profile thereof, are housed.

The plates <NUM> sandwich the sliding plate <NUM> and have respective cavities <NUM>, designed to accommodate the pin <NUM> and to be driven by it along the profile of the curved seats <NUM> during the rotation of the arm <NUM>.

During the final phase of closure of the door, the plates <NUM> compress a damper <NUM> housed between opposing seats <NUM> of the half-shells <NUM>, <NUM> and in a lower recess <NUM> of the plate <NUM>, producing the damping of the door.

From what has been disclosed, the advantages of the device of the invention appear clear, whose components, rather than being arranged in a case, in turn arranged in an external container, as is the case in the prior art, are arranged directly in the container which, suitably shaped, itself acts as guide and container for the elastic elements assigned to the lifting of the door. In this way the overall dimensions of the device are considerably reduced, which can be concealed inside the side of the furniture item.

In the foregoing, the container (<NUM>) has been described as being realised in two half-shells, although it could theoretically be realised as a single shell.

Claim 1:
Device (<NUM>) for lift-up opening of a door (<NUM>) of a kitchen, bathroom, living area furniture item, or of any furniture item in general, comprising a container (<NUM>) that can be attached to the frame of the furniture item, in particular to one of its sides (<NUM>), containing in its interior a mechanism that acts, by means of an arm (<NUM>), articulated to the container (<NUM>) around a fulcrum pin (<NUM>), directly or indirectly on the door (<NUM>), wherein said arm (<NUM>) carries an eccentric pin (<NUM>) that is capable of engaging with a cam profile (<NUM>) of a plate (<NUM>) slidably housed in the container (<NUM>), under the action of at least one spring (<NUM>) acting between said container (<NUM>) and said plate (<NUM>) in a direction opposite to said cam profile, said cam profile (<NUM>) and the action of said at least one spring (<NUM>) balancing the weight of the door in each position during opening and closure, characterised in that said eccentric pin (<NUM>) is housed in an opening (<NUM>) with curved profile that is formed in the container (<NUM>).