FIELD OF THE INVENTION

The present invention concerns a safety device to prevent the sudden closing of a movable element, which is for example hinged or sliding with respect to a fixed element. The movable element could be, for example, the closing element of a piece of furniture or a door, of any weight and size.

BACKGROUND OF THE INVENTION

It is known that stresses of various type and great strength, such as draughts, or thrusts by the user, can cause the abrupt and violent closing of a closing element of a piece of furniture or a door, even of large sizes.

These conditions can constitute situations of potential danger, in particular if a person finds himself in proximity to the door or closing element, for example^or children whose hands can be crushed between the door and the- jamb. Furthermore, the sudden closing of a door can cause damage to the door itself or to the structure which supports it. The problem becomes particularly significant in the case of heavy metal doors, such as fire doors, armor-plated doors and compartmentation doors. In all these cases the mass of the door and the speed it can reach as it closes are decisive factors.

Even if some devices are known which allow to limit or prevent the sudden closing of doors, these have the disadvantage of being rather complex from the mechanical point of view, with a large number of components and are very bulky and not always efficient. Moreover, the known devices do not usually stop the door but only slow it down as it is closing.

From the patent application US-A-2007/0226954 a device is known to prevent a door involuntarily slamming against the corresponding fixed frame on which it is hinged. The known device, to be installed on the fixed frame, comprises a cylinder that slides axially with respect to a hollow seating, thrust toward an open position by a pair of helical springs, with a different elasticity constant and both coaxial to the cylinder itself. The gentle activation of the cylinder by the door causes the spring to be compressed with the smallest elasticity constant and enables the cylinder to slide axially as far as a closed position, with the door against the fixed frame. On the contrary, the abrupt activation of the cylinder by the door makes the spring compress with the maximum elasticity constant, and its compression blocks the cylinder, by means of the radial movement of a clamping ball associated to it and which is normally found in an annular groove of the cylinder. However, this known device has the disadvantage of being bulky and rather long, so that it needs a lot of space to be installed on the fixed frame, particularly in the direction perpendicular to the door, when the latter is closed.

Also the British patent GB 836 and the US patents 1,221,580 and 2,869, 171 describe safety mechanisms to prevent the abrupt closing of a door, all based on the axial sliding of an actuation element.

One purpose of the present invention is to make a safety device which prevents the sudden closing of a movable structure and at the same time is simple and guarantees reliability and safety.

Another purpose of the present invention is to make a safety device which comes into action and blocks the door only when force is applied to it, for example an impulsive force, higher than a determinate value and which instead remains inactive, allowing the normal closing of the movable structure, in all other cases.

Another purpose of the present invention is to make a safety device which takes up a very limited space, above all in a direction transverse to that of the movable element, when the latter is in the closed position, so that it can be easily installed in the corresponding fixed frame, on which the movable element is normally pivoted.

The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.

SUMMARY OF THE INVENTION

The present invention is set forth and characterized in the independent claim, while the dependent claims describe other characteristics of the invention or variants to the main inventive idea.

In accordance with the above purposes, a safety device according to the present invention, which overcomes the limits of the state of the art and eliminates the defects present therein, is provided to be associated to a frame of a piece of furniture or a door, which be a fire door, an armor-plated door, or a compartmentation door, or the door of a house.

According to a main characteristic of the present invention, the safety device comprises a lever mechanism, comprising, in turn, at least two levers articulated with respect to each other and at least two elastic members, with a different elastic constant.

In particular, the lever mechanism comprises at least an actuation lever and a connection lever, connected to the actuation lever in an articulated manner. The latter is pivoted on a pin and is provided to be actuated by the movable element in order to oscillate, with respect to the pin, between an open position and a closed position. The pin of the actuation lever can be fixed, or supported by the connection lever.

A first elastic member is provided to constantly apply a first elastic force on the lever mechanism, to thrust the actuation lever constantly toward the open position.

A sliding element is provided to slide in a guide between an initial position, where the sliding element is to be found when the actuation lever is in the open position, and a final position where the sliding element is to be found when the actuation lever is in a closed position.

A second elastic member is provided to apply a second elastic force, less than the first elastic force, constantly onto the mechanism lever, and to thrust the mechanism lever toward an operating condition, in which the sliding element is free to slide in the corresponding guide between its initial position and its final position.

A clamping member is provided to cooperate with the lever mechanism in order to prevent the sliding element from moving from its initial position toward its final position inside the guide, when a determinate actuation force of the impulsive type exceeding a determinate value, greater at least than that of the second elastic force, is applied suddenly by the movable element on the actuation lever.

The articulated levers and elastic members cooperate with each other so as to receive, transmit and distribute the force applied to the actuation lever of the movable element. In other words, impulsive-type forces of an entity higher than a certain threshold, applied to the actuation lever, overcome the resistance of that one of the two elastic members which functions as an elastic contrast mean, engaging the clamping member, which immediately stops the closing of the movable element. In this case, the device according to the present invention moves into the clamping position. Vice versa, forces of the non impulsive type and/or of an entity lower than the threshold, applied on the actuation lever, allow the elastic contrast mean to not yield, allowing the gentle closing of the closing element of the piece of furniture or door, and bringing the safety device into the closed position.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other characteristics of the present invention will become apparent from the following description of three preferential forms of embodiment, given as a non-restrictive example with reference to the attached drawings wherein: - fig. 1 is a plan view of a first form of embodiment of a safety device according to the present invention, in an open or loaded position;

- fig. 2 is a plan view of the safety device in fig. 1 in a clamping position;

- fig. 3 is a plan view of the safety device in fig. 1 in a closed position;

- fig. 4 is a plan view of a second form of embodiment of a safety device according to the present invention, in an open or loaded position;

- fig. 5 is a plan view of the safety device in fig. 4 in a clamping position;

- fig. 6 is a plan view of the safety device in fig. 4 in a closed position;

- fig. 7 is a plan view of a third form of embodiment of a safety device according to the present invention, in an open or loaded position;

- fig. 8 is a plan view of the safety device in fig. 7 in a clamping position;

- fig. 9 is a plan view of the safety device in fig. 7 in a closed position.

DETAILED DESCRIPTION OF THREE PREFERENTIAL FORMS OF

EMBODIMENT

With reference to figs. 1, 2 and 3, a first form of embodiment of a safety device 10 according to the present invention is described, which can be used to prevent the sudden closing of a movable element, not shown in the drawings, which can be for example a closing element of a piece of furniture or a door, even of considerable size. The safety device 10 comprises a lever mechanism 20, which, in turn, comprises an actuation lever 1 1 and a connection lever 18.

The actuation lever 1 1 is pivoted at one of its ends, by means of a fixed pin 12, to a fixed support 13, provided to be mounted for example on the fixed frame on which the movable element is hinged.

The actuation lever 1 1 comprises, on the side opposite that of the pivoting, a contact end 14, provided to enter into contact with the movable element. The latter is provided to apply an actuation force F on the contact end 14.

The connection lever 18 is pivoted at one of its ends to the actuation lever 1 1 , by means of an articulation pin 15. The opposite end of the connection lever 18 is provided with a sliding element 21, which, in this case, is a peg provided to slide inside a guide slot 23 made in the fixed support 13. The guide slot 23 in this case is shaped like an L, so as to define a sliding cavity 27 and a clamping cavity 26, communicating and orthogonal with respect to each other.

The sliding element 21 is normally held in an initial position, shown in fig. 1 , by a first elastic member, which in this case is a helical spring 25, taut between the fixed support 13 and the actuation lever 1 1. In the example shown here, the helical spring 25 applies a first elastic force Rl, in the order of some tens of Newtons, for example about 20 N, on the actuation lever 11.

The connection lever 18 is provided to be thrust, by means of the sliding element 21, by a second elastic member, which in this case is a leaf spring 30, anchored to the fixed support 13 by means of an attachment element of a known type. In this way, the leaf spring 30 constantly applies a second elastic force R2, which is much less than Rl, for example about 1 N, on the sliding element 21. The second elastic force R2 normally holds the sliding element 21 in an operating condition which allows it to slide along the sliding cavity 27.

The safety device 10 as described heretofore functions as follows.

When the movable element (for example a door or a closing element of a piece of furniture) is open, the safety device 10 is in an open position, or loaded position shown in fig. 1. In this position the helical spring 25 holds the actuation lever 1 1 substantially orthogonal to the connection lever 18, as the sliding element 21 is temporarily against the corner of the guide slot 23 formed by the two sliding 27 and clamping 26 cavities. When a determinate impulsive-type actuation force F exceeding a determinate value, greater than that of the second elastic force R2, is applied suddenly by the movable element onto the actuation lever 11, the safety device 10 moves into the clamping position shown in fig. 2 and prevents the movable element from slamming against the corresponding fixed frame. Indeed, the impulsive-type actuation force F, higher than a certain threshold and applied to the actuation lever 11, overcomes the resistance of the leaf spring 30 and not that of the helical spring 25. Consequently, the sliding element 21 is thus inserted inside the clamping cavity 26 and stops the rotation of the actuation lever 1 1 with respect to its fixed pin 12, and therefore that of the movable element. In this case, the actuation lever 1 1 and the connection lever 18 remain substantially orthogonal with respect to each other.

On the contrary, when the movable element closes gently and applies a determinate actuation force F, less than that of the second elastic force R2, onto the contact end 14 of the actuation lever 1 1, the safety device 10 does not block, and moves into a closed position shown in fig. 3. Indeed, in this case, the leaf spring 30 does not yield, so that the sliding element 21 can slide along the sliding cavity 27 as far as a final position, allowing the gentle closing of the closing element of the piece of furniture or of the door in contact with the actuation lever 1 1. In this case, the connection lever 18 is disposed substantially parallel to the actuation lever 1 1, and both the levers 1 1 and 18 are contained inside the fixed support 13.

The helical spring 25 allows to return the safety device 10 to the loaded position at the moment when the closing element of the piece of furniture or the door is reopened.

In accordance with a second form of embodiment of the present invention, a safety device 1 10 (figs. 4, 5 and 6) comprises a lever mechanism 120 which in turn comprises an actuation lever 1 1 1 and a connection lever 1 18.

The actuation lever 1 1 1 is pivoted with one end on a fixed pin 112 of a fixed support 1 13, provided to be mounted on the fixed frame for example on which the movable element is hinged.

The actuation lever 1 1 1 comprises, on the side opposite that of the pivoting, a contact end 1 14, provided to enter into contact with the movable element. The latter is provided to apply an actuation force F on the contact end 1 14. The rotation in a clockwise direction of the actuation lever 1 11 is limited by a stop element 1 16, anchored to the fixed support 113.

The mechanism lever 120 also comprises an intermediate lever 1 17, which has one of its ends articulated on a peg 115 of the actuation lever 1 11 and the opposite end articulated on a peg 127 of the connection lever 1 18. The end of the connection lever 1 18 opposite the one where there is the peg 127 is connected to a block 121, by means of a peg 122. The block 121, which acts as a sliding element, is provided to slide along a rectilinear guide slot 123, by means of the peg 122 and an auxiliary peg 124, between an initial position, shown in fig. 4, and a final position, shown in fig. 6. The presence of the auxiliary peg 124 guarantees that the motion of the block 121 is rectilinear. Normally the block 121 is maintained in its initial position by a helical spring 125, fixed, at its opposite end, to the fixed support 113. The helical spring 125 constitutes the first elastic member, able to apply the first elastic force Rl.

The connection lever 118 is provided with a toothing 128, provided to engage with a corresponding fixed toothing 129, solid with the fixed support 1 13.

The connection lever 118 is provided to enter into contact with a leaf spring 130, which constitutes the second elastic member able to apply the second elastic force R2. The leaf spring 130 is anchored to the fixed support 1 13 by means of a fixed element of the known type.

The safety device 1 10 as described heretofore functions as follows.

When the movable element (for example a door or a closing element of a piece of furniture) is open, the safety device 1 10 is in the open position, or loaded position, as shown in fig. 4. In this position the actuation lever 1 1 1 is substantially orthogonal to the intermediate lever 1 17. Moreover the toothing 128 is slightly distanced from the fixed toothing 129.

When a determinate impulsive-type actuation force F exceeding a determinate value, greater than that of the second elastic force R2, is applied suddenly by the movable element on the actuation lever 1 1 1, the safety device 1 10 moves into the clamping position shown in fig. 5 and prevents the movable element from slamming against the corresponding fixed frame. In fact the impulsive-type actuation force F, higher than a certain threshold and applied to the actuation lever 111, first overcomes the resistance of the leaf spring 130 and not that of the helical spring 125. Consequently, the toothing 128 of the connection lever 1 18 engages with the fixed toothing 129, immediately blocking the rotation of the actuation lever 1 1 1 in an anti clockwise direction around its own fixed pin 1 12 and consequently stopping the closing of the closing element of the piece of furniture or the door.

In this case the actuation lever 1 11 and the intermediate lever 1 17 remain substantially orthogonal with respect to each other.

On the contrary, when the movable element closes gently and applies a determinate actuation force F, less than that of the second elastic force R2, on the contact end 1 14 of the actuation lever 1 1 1, the safety device 1 10 does not block and moves into a closed position shown in fig. 6. In fact, in this case, the leaf spring 30 does not yield, so that the toothing 128 does not engage with the corresponding fixed toothing 129 and the block 121 can slide linearly, in its operating condition, until it moves into its final position, allowing the gentle closing of the closing element of the piece of furniture or the door in contact with the actuation lever 1 1 1. In this case the intermediate lever 1 17 and the connection lever 1 18 are disposed substantially parallel to the actuation lever 11 1, and all three levers 11 1, 1 17 and 118 are contained within the fixed support 13.

The helical spring 125 allows to return the safety device 10 back into the loaded position, at the moment when the closing element of the piece of furniture or the door is re-opened.

In accordance with a third form of embodiment of the present invention, a safety device 210 (figs. 7, 8 and 9) comprises a lever mechanism 220 which in turn comprises an actuation lever 21 1 and a connection lever 218.

The actuation lever 211 comprises a central part which is pivoted on a pin 215, which is mounted at a first end 218a of the connection lever 218. The latter, in turn, is pivoted with its second end 218b, opposite the first end 218a, on a fixed pin 212 of a fixed support 213, provided to be mounted for example on the fixed frame on which the movable element is hinged.

At a first end 221a of the actuation lever 211 a contact wheel 214 is mounted, provided to enter into contact with the movable element. The latter is provided to apply an actuation force F to the contact wheel 214, and therefore to the actuation lever 21 1.

At a second end 21 1b of the actuation lever 21 1 a sliding element 21 1 is mounted, which in this case is a peg provided to slide inside a guide slot 223, similar to the slot 23 in the first form of embodiment, and made in the fixed support 213. In fact, the guide slot 223 is also L shaped, so as to define a sliding cavity 227 and a clamping cavity 226, communicating and orthogonal with respect to each other.

The sliding element 221 is normally held in an initial position, shown in fig. 7, by a helical spring 225, disposed coaxial to the fixed pin 212 and compressed between the fixed support 213 and the connection lever 218. The helical spring 225 represents the first elastic member of the safety device 210, able to apply the first elastic force Rl .

A leaf spring 230, which constitutes the second elastic member able to apply the second elastic force R2, is anchored to the fixed support 213 and is provided to cooperate with the sliding element 221 in order to keep it in the initial position, in an operating condition.

The safety device 210 as described heretofore functions as follows.

When the movable element (for example a door or a closing element of a piece of furniture) is open, the safety device 210 is in the open position, or loaded position, shown in fig. 7. In this position the helical spring 225 holds the actuation lever 21 1 substantially orthogonal to the connection lever 218, since the sliding element 221 is temporarily thrust by the leaf spring 230 against the corner of the guide slot 223 formed by the two sliding 227 and clamping 226 cavities. When a determinate impulsive-type actuation force F exceeding a determinate value, greater than that of the second elastic force R2, is applied suddenly by the movable element on the actuation lever 211, the safety device 210 moves into the clamping position shown in fig. 8 and prevents the movable element from slamming against the corresponding fixed frame. In fact the impulsive-type actuation force F and higher than a certain threshold, applied to the actuation lever 21 1, makes the latter rotate in an anti-clockwise direction with respect to its pin 215, because it overcomes first the resistance of the leaf spring 230 and not that of the helical spring 225. Consequently the sliding element 221 is inserted inside the clamping cavity 226 and stops the rotation of the actuation lever 21 1 with respect to its pin 215, and therefore also that of the movable element with respect to the fixed frame. In this case the actuation lever 21 1 and the connection lever 18 remain substantially orthogonal with respect to each other.

On the contrary, when the movable element closes gently and applies a determinate actuation force F, less than that of the second elastic force R2, on the end 21 1a of the actuation lever 21 1, the safety device 210 does not block and moves into a closed position shown in fig. 9. In fact, in this case, the leaf spring 230 does not yield, so that the sliding element 221 remains in its operating condition and can slide freely along the sliding cavity 227 until it moves to its final position, allowing the gentle closing of the closing element of the piece of furniture or of the door in contact with the actuation lever 211. In this case the connection lever 218 is disposed substantially parallel to the actuation lever 21 1, and both levers 21 1 and 218 are contained within the fixed support 213.

The helical spring 225 allows to return the safety device 210 back into the loaded position, at the moment when the closing element of the piece of furniture or the door is re-opened.

Also in the second safety device 1 10 and in the third safety device 210 the first elastic force Rl is in the order of about 20 N and the second elastic force R2 is in the order of about 1 N.

It can be noted that in all three forms of embodiment, the lever mechanism 20, 120, 220 described above is completely inside the space defined by the fixed support 13, 1 13, 213, respectively, when the actuation lever 1 1, 1 1 1, 21 1 is in the closed position.

It is clear that modifications and/or additions of parts may be made to the safety device 10, 1 10, 210 as described heretofore, without departing from the field and scope of the present invention.

It is also clear that, although the present invention has been described with reference to some specific examples, a person of skill in the art shall certainly be able to achieve many other equivalent forms of safety device, having the characteristics as set forth in the claims and hence all coming within the field of protection defined thereby.