[0001] The present patent application refers to a system used to automatically push furniture
drawers or any other pull-out structure for furniture, such as columns or shelf/basket-holding
racks, to end of opening and closing travel.
[0002] Patent protection is also extended to the furniture provided with the system of the
invention.
[0003] The purpose of the invention is to find a solution to a problem that has recently
drawn the attention of furniture manufacturers, with special reference to modular
kitchens. In addition to ordinary drawers, modular kitchen units are often fitted
with shelf-holding metal frames that slide on horizontal guides, in such a way that
they can be partially or totally pulled out of the unit to make loading and unloading
operations easier.
[0004] This type of units is normally closed with a door fixed on the front of the bearing
structure and designed to follow the alternate opening and closing travels of the
structure that slides on telescopic guides.
[0005] The aforementioned problem refers to perfect closing of pull-out structures: perfect
closing should be ensured with requiring the user's special attention to avoid causing
a violent shock at the end of the closing travel, which may stress the pull-out structure,
and especially the front covering panel, whose borders engage with the borders of
the walls of the unit in which the pull-out element is contained.
[0006] To avoid the aforementioned elements, the user should gently push the pull-out element
along its entire closing travel, without pushing it too strongly; however, low acceleration
might not be sufficient to guarantee complete closing, while high acceleration would
cause a dangerous shock at the end of the closing travel.
[0007] Based on the aforementioned considerations, automatic devices used to guarantee perfect
closing of pull-out elements for furniture have been devised recently.
[0008] Although of different construction, these devices have the same operating principle
based on a spring that automatically engages with the pull-out element in the last
section of the closing travel, designed to bring it to the end of the travel.
[0009] The spring actuates in combination with a shock-absorbing means, usually an hydraulic
cylinder, designed to oppose the action of the spring to ensure slow and gentle closing
to the end of the travel.
[0010] The opening travel of the pull-out element is entirely entrusted to the user, who
initially exerts sufficient force to load the return spring, which automatically disengages
from the pull-out element and remains loaded after the first section of the opening
travel.
[0011] The known devices are not designed or able to control and manage the last section
of the opening travel, which may cause the same inconvenience described above, in
case of brisk opening of the pull-out element with a violent stop at the end of the
travel.
[0012] In such a case, the most stressed elements would be the stops located on the telescopic
sliding guides and the fixing elements of the front covering panel, where the driving
force exerted by the user's hand is discharged.
[0013] Based on the above considerations, a system has been devised to automatically guarantee
complete closing and opening of pull-out elements, ensuring soft closing and opening
thanks to the absorbed braking action opposed to the force that pushes the pull-out
element at the end of the opening or closing travel.
[0014] Another purpose of the invention is to devise a system that guarantees stable balance
of the pull-out element in maximum opening position.
[0015] This additional result has been achieved thanks to the fact that the pull-out element
is subject to a modest expulsive action, after reaching the end of the opening travel,
to oppose the backward motion of the pull-out element in case of accidental push or
shock.
[0016] The system of the invention makes use of ordinary gas springs located in intermediate
position between the furniture frame and pull-out element.
[0017] In the preferred embodiment of the system of the invention, the gas spring is placed
between the furniture frame and the pull-out element frame; however, the desired result
can also be achieved by fixing the gas spring to any other structure that slides with
the pull-out element, such as the rod of the telescopic guide that is directly fixed
to the pull-out element frame.
[0018] Gas springs are composed of a cylinder, whose stem constantly receives the expulsive
action of the compressed air contained in the cylinder, with the possibility of adjusting
the power of the said action by changing the air pressure.
[0019] The expulsion travel of the stem is opposed by the resistance caused by oil seeping
between two adjacent chambers inside the cylinder, it being provided with small overflows
in one direction and large overflows in the opposite direction, in such a way that
the oil flow from one chamber to the other one does not generate appreciable resistance
when the stem is pushed inside the cylinder and vice versa.
[0020] According to the system of the invention, the cylinder of gas springs is fixed to
the furniture frame near the opening by means to a first horizontal pivoting pin,
while the end of the stem in extended position is fixed to the pull-out element frame
or to any other structure that slides together with the pull-out element by means
of a second horizontal pivoting pin.
[0021] In order to open or close the pull-out element, the user must exercise a traction
or push force on the pull-out element only for a first section of the travel, that
is to say the section that corresponds to the insertion of the stem inside the cylinder
and ends with a dead point, in which the cylinder is in a vertical position that corresponds
to the maximum retraction of the stem.
[0022] After the dead point, the stem starts to extend and automatically continues extension
under the expulsive action of the air, whose pressure reaches the maximum pressure
in the said dead point.
[0023] After the dead point, the compressed air pushes the pull-out element until it reaches
complete opening or closing, thus guaranteeing soft stop at the end of the travel,
thanks to the braking action that intervenes always and only during the extension
of the stem.
[0024] For major clarity, the description of the system of the invention continues with
reference to the enclosed drawings, which are intended for purposes of illustration
only and not in a limiting sense, whereby:
- Fig. 1 is a diagrammatic axonometric view of a unit sectioned with a vertical plane,
provided with the system of the invention to move a pull-out element housed inside
the unit, of the type composed of a rack, shown in completely inserted position inside
the unit;
- Fig. 2 is basically the same as Fig. 1, except for the fact that it shows the pull-out
rack in completely extracted position from the unit;
[0025] With reference to the aforementioned figures, the system of the invention makes use
of ordinary gas springs (1) positioned between the bearing structure of the unit (2)
and the frame (3) of the pull-out element (4). In the aforementioned figures, the
pull-out element (4) consists in a rack formed of a rectangular metal frame, composed
of two transversal rods (4a) and two uprights (4b), provided with hooks (4c) used
to support wire baskets, not shown, overhanging on the front of the frame, which lays
and slides on a vertical plane, near one of the sides (2a) of the unit (2).
[0026] Telescopic guides (5) are positioned between the pull-out element (4) and the side
(2a), whose sliding rod is fixed to the transversal rods (4a), while the bearing track
of the guide (5) is fixed to the side (2a).
[0027] According to the system of the invention, the cylinder (1 a) of the gas springs (1)
is fixed to the side (2a) of the unit (2) by means to a first horizontal pivoting
pin (6), while the end of the stem (1 b) in extended position is fixed to the frame
of the pull-out element (4) frame by means of a second horizontal pivoting pin (7),
after bringing the pull-out element (4) at the end of the opening or closing travel.
[0028] In this case, the stem (1 b) is fixed to the frame of the pull-out element (4) on
the lower transversal rod (4a).
1. System used to automatically push pull-out elements of furniture units to the end
of the opening and closing travel, characterised in that it makes use of ordinary gas springs (1) positioned between the frame of the unit
(2) and the pull-out element (4), in such a way that the last section of the closing
and opening travel of the pull-out element (4) is carried out automatically under
the absorbed action exercised by the gas springs (1) during extension.
2. System used to automatically push pull-out elements of furniture units to the end
of the opening and closing travel, as defined in claim 1, characterised in that the gas springs (1) are positioned between the frame of the unit (2) and the frame
of the pull-out element (4).
3. System used to automatically push pull-out elements of furniture units to the end
of the opening and closing travel, as defined in claim 1, characterised in that the gas springs (1) are positioned between the frame of the unit (2) and a structure
that slides together with the pull-out element (4).
4. System used to automatically push pull-out elements of furniture units to the end
of the opening and closing travel, as defined in claim 3, characterised in that the gas springs (3) are positioned between the frame of the unit (2) and the telescopic
rod (5) fixed directly to the frame of the pull-out element (4).
5. Furniture unit housing one or more pull-out elements that slide on guides, characterised in that it is provided with gas springs (1) positioned between the furniture unit (2) and
pull-out element (4) to automatically push the pull-out element (4) to the end of
the opening and closing travel, according to the system described in the four preceding
claims.