阅读说明：本技术 用于自动关闭/开启滑门或百叶窗的系统 (System for automatically closing/opening sliding doors or shutters ) 是由 路西安诺·巴茄堤 于 2018-02-02 设计创作，主要内容包括：一种用于自动关闭/开启孔口(P)的系统,其包括：至少一个关闭元件(D),其可在平面中在关闭位置与开启位置之间滑动,在所述关闭位置中,所述孔口(P)关闭,且在所述开启位置中,所述孔口(P)开启；以及至少一个线性致动器(1),其与所述至少一个关闭元件(D)操作性地联接,以使所述至少一个关闭元件从所述开启位置和所述关闭位置中的一个自动地返回到所述开启位置和所述关闭位置中的另一个。所述线性致动器(1)包含限定轴线(X)的至少一个护套(10)和可相对于所述至少一个护套(10)往复滑动的至少一个杆(20)。所述线性致动器(1)包含固定元件和可移动元件,所述固定元件和所述可移动元件中的一个包含所述至少一个护套(10),所述固定元件和所述可移动元件中的另一个包含所述至少一个杆(20)。所述系统进一步包含用于滑动所述线性致动器(1)的所述可移动元件的至少一个导轨(120),所述至少一个导轨限定基本上平行于所述轴线(X)的滑动方向(d)。(A system for automatically closing/opening an orifice (P), comprising: at least one closing element (D) slidable in a plane between a closed position, in which said orifice (P) is closed, and an open position, in which said orifice (P) is open; and at least one linear actuator (1) operatively coupled with said at least one closing element (D) to automatically return said at least one closing element from one of said open position and said closed position to the other of said open position and said closed position. The linear actuator (1) comprises at least one sheath (10) defining an axis (X) and at least one rod (20) reciprocally slidable with respect to said at least one sheath (10). The linear actuator (1) comprises a fixed element and a movable element, one of the fixed element and the movable element comprising the at least one sheath (10) and the other of the fixed element and the movable element comprising the at least one rod (20). The system further comprises at least one guide rail (120) for sliding the movable element of the linear actuator (1), said at least one guide rail defining a sliding direction (d) substantially parallel to the axis (X).)

1. A system for automatically closing/opening an orifice (P), comprising:

at least one closing element (D) slidable in a plane between a closed position, in which said orifice (P) is closed, and an open position, in which said orifice (P) is open;

at least one linear actuator (1) operatively coupled with said at least one closing element (D) to automatically return said at least one closing element from one of said open position and said closed position to the other of said open position and said closed position;

wherein the linear actuator (1) comprises at least one sheath (10) defining an axis (X) substantially parallel to said plane and at least one rod (20) reciprocally slidable with respect to said at least one sheath (10);

wherein the linear actuator (1) comprises a fixed element and a movable element, one of which comprises the at least one sheath (10) and the other of which comprises the at least one rod (20), the movable element of the linear actuator (1) being interconnected with the at least one closing element (D) so as to slide along the axis (X), the system further comprising at least one guide rail (120) for sliding the movable element of the linear actuator (1), the at least one guide rail (120) defining a sliding direction (D) substantially parallel to the axis (X);

wherein said at least one rod (20) has an end cylinder (21) inserted tightly into said at least one sheath (10) and an opposite end (22) external to said at least one sheath and reciprocally slidable along said axis (X) or an axis parallel thereto between a position proximal to said at least one sheath (10) and a position distal to said at least one sheath;

wherein the at least one sheath (10) comprises a motion-promoting member (40) acting on the at least one rod (20) to move the opposite tip (22) from the other of the distal or proximal position to the other of the distal or proximal position when the opposite tip (22) is moved from the other of the distal or proximal position to the one of the distal or proximal position;

wherein said movement promoting means comprise at least one elastic element (40) operatively connected with said at least one sheath (10) and with said at least one rod (20), said at least one rod (20) being hollow inside, said at least one elastic element (40) being placed inside said at least one rod (20);

wherein the at least one sheath (10) further comprises a damping member (18', 18", 260, 18', 18", 50) acting on the at least one rod (20) to damp the movement of the opposing tip (22) when the opposing tip moves from the one of the distal or proximal positions to the other of the distal or proximal positions;

wherein the damping member (18', 18", 260, 18', 18", 50) is active when the opposite tip (22) returns from the distal position to the proximal position;

wherein the tip cylinder (21) divides the at least one jacket (10) into at least one first and second variable volume compartments (18', 18"), the damping member (18', 18", 260; 18', 18", 50) comprising a working fluid placed in at least one of the at least one first and second variable volume compartments (18', 18");

wherein the working fluid is a pneumatic fluid, the at least one first and second variable volume compartments (18', 18") being not in fluid communication with each other and each being in fluid communication with the external environment.

2. System according to claim 1, wherein the movable element of the linear actuator (1) comprises the at least one sheath (10), the fixed element of the linear actuator (1) comprises the at least one rod (20), the sliding means comprise at least one pair of sliders (110, 111) to be coupled with the at least one sheath (10).

3. The system according to claim 1, further comprising a hollow elongated profile (130) comprising said at least one guide rail (120), said linear actuator (1) being inserted hidden within said elongated profile (130).

4. System according to claim 3, wherein said at least one closing element (D) further comprises a frame, said elongated profile (130) being inserted within or being an integral part of said frame.

5. System according to claim 4, wherein said hollow elongated profile (130) is placed above said at least one closing element (D).

6. The system according to claim 1, wherein the at least one sheath (10) comprises an end (13") proximal to the opposite end (22) of the at least one rod (20) and an end (13') distal thereto, the at least one sheath (10) comprising a first member (160) at the distal end (13') for interoperability connection with the at least one resilient element (40), the at least one rod (20) comprising a second member (250) at the opposite end (22) for interoperability connection with the at least one resilient element (40);

wherein said at least one elastic element comprises at least one coil spring (40), said first operative connection member comprising a first threaded element (160) fixed at said distal end (13') and interconnected with one end (41') of said coil spring (40), said second operative connection member comprising a second threaded element (250) fixed at said opposite end (22) and interconnected with the other end (41') of said coil spring (40).

7. The system of claim 1, wherein one of the at least one first and second variable volume compartments (18', 18") is expanded by at least partially filling with the working fluid and the other of the at least one first and second variable volume compartments (18', 18") is contracted when the opposite tip (22) is moved from the one of the distal position or the proximal position to the other of the distal position or the proximal position, and wherein the other of the at least one first and second variable volume compartments (18', 18") is expanded and the at least one first and second variable volume compartments (18'; 18") is contracted when the opposite tip (22) is moved from the other of the distal position or the proximal position to the one of the distal position or the proximal position, 18") to cause the working fluid to at least partially flow out, the damping member (18', 18", 260; 18', 18", 50) further comprises means (260; 50).

8. The system of claim 1, wherein the pneumatic working fluid is ambient air blown from or into the external environment.

9. The system of claim 8, wherein the one of the at least one first and second variable volume compartments (18', 18") is in fluid communication with the external environment via the control member (50), the control member including a valve member (50) configured to allow aspiration of the pneumatic working fluid from the external environment when the opposing tip (22) moves from the one of the distal or proximal positions to the other of the distal or proximal positions, and to allow controlled blowout thereof when moved in a reverse direction.

10. The system of claim 9, wherein the valve member (50) comprises a valve body (160, 170) having a first opening (51) in fluid communication with the external environment and a second opening (54) in fluid communication with said one of the at least one first and second variable volume compartments (18', 18"), the valve member (50) further comprising a valve plug (57) selectively acting on the first opening (51) to allow the pneumatic working fluid to be sucked/blown from/out to the external environment.

11. The system of claim 10, wherein the valve plug (57) is movable between a first operative position away from the first opening (51), in which a flow cross-section of the pneumatic working fluid entering the one of the at least one first and second variable volume compartments (18', 18") has a first predetermined size, and a second operative position contacting the first opening (51), in which the flow cross-section of the pneumatic working fluid blown out of the one of the at least one first and second variable volume compartments (18', 18") has a second size lower than the first size.

12. The system of claim 11, wherein the first and second openings (51, 54) comprise through-pins (56) slidably inserted therethrough to define respective first and second alignment holes.

Technical Field

The present invention is generally applicable to the technical field of mobile systems and in particular relates to a system for opening/closing an aperture, comprising a linear actuator slidable integrally with a door, a door leaf or the like.

Background

It is well known that there are two main types of linear actuators, namely hydraulic or pneumatic linear actuators.

In both cases, the actuator must be connected to a supply line of working fluid (oil or compressed air).

This clearly implies the disadvantage of using a working fluid to deal with all the problems involved. These kinds of actuators are therefore not suitable for several non-industrial applications, such as the movement of sliding doors or door leaves.

Compression and traction gas springs are also known. In these kinds of springs, once the spring is pushed or pulled to the working position, a gas, usually nitrogen, is used to bring the rod back to its rest position.

A known disadvantage of these kinds of springs is that they tend to be expelled over time, forcing their periodic replacement. Furthermore, since the rod is to oppose the gas when the rod is compressed or pulled, the pressure of the gas increases, and as a result, the force necessary to move the rod increases.

Disclosure of Invention

The object of the present invention is to overcome at least partially the above drawbacks by providing a linear actuator with high functionality, constructional simplicity and low cost characteristics.

Another object of the present invention is to provide a system for opening/closing a sliding door or leaf which always requires the same force to move the sliding door or leaf, regardless of the position of the sliding door or leaf.

Another object of the present invention is to provide a system for opening/closing sliding doors or leaves which requires minimum maintenance.

Another object of the present invention is to provide a system for opening/closing sliding doors or leaves which has limited overall dimensions.

Another object of the present invention is to provide an actuator which ensures automatic closing/opening of the door or leaf from the open/closed position.

Another object of the present invention is to provide a system for opening/closing a sliding door or leaf which ensures a controlled movement of the sliding door or leaf.

Another object of the present invention is to provide a system for opening/closing a sliding door or leaf with a minimum number of components.

These objects, as well as others which will become more apparent hereinafter, are achieved by an open/close system with a closing element according to what is described, illustrated and/or claimed herein.

The dependent claims describe advantageous embodiments of the invention.

Drawings

Further characteristics and advantages of the invention will be more apparent when considering the detailed description of some preferred but not mutually exclusive embodiments of the system 1, illustrated as a non-limiting example by means of the accompanying drawings, in which:

fig. 1a and 2a are schematic views of an embodiment of a system 100 for closing an aperture P by means of a sliding door D moved by a preferred non-exclusive embodiment of a linear actuator 1 in a closed door position D and an open door position D, respectively;

fig. 1b and 2b are schematic views of an embodiment of the linear actuator 1 of fig. 1a and 2a in a door closed position D and a door open position D, respectively;

fig. 3 is an exploded view of an embodiment of the linear actuator 1 of fig. 1a and 2 a;

fig. 4a and 4b are sectional views of the ends 13 "and 13', respectively, of the tubular element 11 of the embodiment of the linear actuator 1 of fig. 1a and 1b in the closed door position D;

fig. 5 is a cross-sectional view of the end 13 "of the tubular element 11 of the embodiment of the linear actuator 1 of fig. 2a and 2b in the door open position D;

fig. 6 is a cross-sectional view of the tip 13 "of the tubular element 11 of another embodiment of the linear actuator 1 with the tip 22 in a distal position;

FIG. 7 is a cross-sectional view of the distal end 13' of the tubular element 11 of another embodiment of the linear actuator 1 of FIG. 6 with the distal end 22 in a proximal position;

fig. 8a and 8b are enlarged schematic views of an embodiment of the system 100 of fig. 1a and 2a, showing the linear actuator 1 in a door closed position D and a door open position D;

figures 9a and 9b are cross-sectional views of the embodiment of the linear actuator 1 shown in figures 8a and 8b in the closed door position D and the open door position D, respectively;

fig. 10 is an exploded view of another embodiment of the linear actuator 1;

fig. 11A and 11B are sectional views of the embodiment of the linear actuator 1 of fig. 10 with the door leaf D in the closed position and the open position, respectively;

fig. 12 is an exploded view of a second embodiment of the linear actuator 1;

fig. 13A and 13B are sectional views of the embodiment of the linear actuator 1 of fig. 12 with the door leaf D in the closed position and the open position, respectively.

Detailed Description

With reference to the mentioned figures, a linear actuator 1 is described, which is adapted to linearly move any object, mechanism or system. The linear actuator may act directly or indirectly by means of a pulley or transfer mechanism.

In a preferred but not mutually exclusive embodiment of the invention, the linear actuator 1 can be used in a system 100 for closing/opening an orifice P by means of a closing element D movable between an open position and a closed position.

In general, the aperture P may be any opening made in any fixed support structure, and the closing element D may be of any kind, such as a door, a leaf, a hatch, a blank door, etc. Likewise, the closing element D can move in any movement, either linearly along a sliding plane or rotationally about a rotation axis.

In the latter case, the linear actuator 1 may act as a door closer or hinge device, or may be an integral part thereof. The closing element D may be a door, a door leaf or the like.

For example, as shown in fig. 1a and 2a, the aperture P may be a passage made in the wall W, and the closing element D may be a sliding door in a plane defined by the door itself between a closed position shown in fig. 1a and an open position shown in fig. 2 a. Preferably, in the open position, the closing element D can be completely open.

Fig. 1b and 2b show the linear actuator 1 in a position corresponding to fig. 1a and 2a, respectively.

On the other hand, the aperture P may be a passage made in a frame, for example a frame of a refrigerated cabinet, and the closing element D may be a sliding door leaf.

In general, the linear actuator 1 may comprise a sheath 10 defining an axis X and a rod 20 movable therefrom between a retracted position, for example shown in fig. 1b, and an extended position, for example shown in fig. 2 b.

In the following, even though the sheath 10 is described as an element movable with respect to the fixation rod 20, it is understood that the opposite situation may occur, i.e. the rod may be moved with respect to the fixation sheath, without thereby going beyond the scope of protection of the appended claims.

It should also be understood that even if a single rod 20 and a single sheath 10 are provided in the embodiment shown, the linear actuator 1 may comprise a plurality of sheaths and/or a plurality of rods, since it may be coupled to other actuators, for example gas springs of known type, without thereby going beyond the scope of protection of the appended claims.

In any case, the moving element of the linear actuator 1, i.e. the sheath 10, in the embodiment shown in the figures, can be connected to the sliding door D, while the fixed element, i.e. the rod 20, in the embodiment shown in the figures, can be fixed to the wall W.

Thus, the sheath 10 will slide integrally with the door between its open and closed positions.

For this purpose, sliding members, such as two or more slides 110, 111, can be provided, operatively engaged in one or more guides 120 defining a sliding direction d substantially parallel to the axis X defined by the sheath.

Advantageously, the sliders 110, 111 may be coupled to, for example slidably inserted on, the tubular element 11 of the linear actuator 10.

In this way a compact and simple way of achieving a functional linear actuator is obtained.

These features allow it to be a hidden elongated or internally open C-shaped tubular member 130 that can be inserted into or be an integral part of a door frame or false ceiling.

Preferably, the profile 130 with the linear actuator 1 can be positioned above the sliding door D. On the other hand, it can also be positioned transversely to the door D or even lower than it, using suitable return means such as pulleys and ropes.

The linear actuator 1 that can be used in the system 100 can be of any type.

In a preferred but not mutually exclusive embodiment of the system 100, particularly illustrated in fig. 3 to 7, the actuator 1 may have the characteristics described below.

Even though in the remaining description the linear actuator 1 is described for moving the sliding door D, it is understood that the linear actuator 1 may have any use without thereby going beyond the scope of protection of the appended claims.

As mentioned above, in the description of the present invention, the concept of sliding between the rod 20 and the sheath 10 and the opposing parts must be understood in an relative, rather than absolute, manner. Thus, even if for the sake of simplicity it is proposed that the rod 20 slides with respect to the sheath 10, it must be understood that the sliding between these parts is reciprocal and with respect to each other.

In the embodiment shown in fig. 1a to 5, the retracted position of fig. 1b, which corresponds to the door-closed position D, corresponds to the rest position of the linear actuator 1, i.e. the position in which the linear actuator 1 itself is not subjected to stress by external forces.

On the other hand, the extended position of fig. 2b, which corresponds to the door open position D, corresponds to the working position of the linear actuator 1, i.e. the position in which the linear actuator 1 is subjected to stress due to the force that the user gives to the door to open it. From this position, the linear actuator 1 automatically closes the door D, or likewise, the linear actuator 1 automatically returns to its rest position.

In this embodiment, the linear actuator 1 therefore acts in traction.

Advantageously, the rod 20 may comprise an end cylinder 21 and an opposite end 22, both of which can naturally slide integrally with each other along the axis X by means of the rod 20. Thus, the end cylinder 21 will slide between the rest position and the working position.

It will be understood that in the case of a rod bent or having a suitable shape, the tip 22 can slide along an axis substantially parallel to the X-axis, without thereby departing from the scope of protection of the appended claims.

The terminal cylinder 21 can slide tightly inside the jacket 10 by means of a gasket 23 of known type. The opposite end 22 is slidable outwards from the sheath 10 between a position proximal to the sheath (corresponding to the rest position shown in fig. 1 b) and a distal position thereof (corresponding to the work position shown in fig. 2 b).

The sheath 10 may comprise a tubular element 11 defining its side walls, an end cap 12 tightly screwed at an end 13' of the tubular element 11 and a closing element 14 tightly screwed at the other end 13 "of the tubular element 11.

The rod 20 can be inserted through the opening 15 through the wall 14' of the closing element 14.

Advantageously, the stem 20 and the tubular element 11 can be mutually configured so that the bottom wall 16 of the end cap 12 contacts the terminal cylinder 21 when the terminal end 22 is in the proximal rest position, as shown in particular in fig. 4b, for example.

The end cylinder 21 may divide the jacket 10 into first and second variable volume compartments 18', 18 "that are fluidly independent of each other, i.e., compartments that are not fluidly connected to each other and do not exchange any fluid.

When the tip 22 is in the rest position as shown, for example, in fig. 1b, the variable volume compartment 18' has a minimum volume and the variable volume compartment 18 "has a maximum volume, the reverse occurs when the tip 22 is in the working position as shown, for example, in fig. 2 b.

Since the end cap 12 is tightly screwed into the tubular element 11 and the end cylinder 21 is tightly inserted into the tubular element, the compartment 18' is fluidly isolated, i.e. any fluid cannot enter/exit therefrom.

On the other hand, compartment 18' is under vacuum, since bottom wall 16 of end cap 12 is in contact with end cylinder 21 when end 22 is in a rest position, such as shown in fig. 1b, in particular, as shown in fig. 4 b. Thus, in this position, the volume of the compartment 18' corresponding to its minimum volume is substantially zero, as is the pressure inside it.

For this purpose, screwing of the end cap 12 can be carried out when the end cylinder 21 is already at the end 13' of the tubular element 11. This occurs when the tip 22 is in a proximal rest position such as shown in fig. 1 b. In fact, by inserting the terminal cylinder 21 through the terminal 13", it is possible to evacuate substantially all the air from the compartment 18', which is then blocked with the end cap 12.

In this way, it is ensured that the compartment 18' is maintained under vacuum without the aid of an external vacuum pump or component.

However, it is understood that it may be possible to place the compartment 18' under vacuum in any way, for example by connecting it to an external pump or vacuum member, without thereby departing from the scope of protection of the appended claims.

Advantageously, the compartment 18 "may be in fluid communication with the external environment. In this way, the compartment 18 "may be at atmospheric pressure, i.e. at the pressure of the external environment.

Based on the above, in the closed door position shown in fig. 1a, the tip cylinder 21 is held against the bottom wall 16 of the tip plug 12, and thus the tip 22 is held in a rest position proximal to the sheath 10.

Once the user opens the shutter D, i.e. when the tip 22 moves from the rest position proximal to the sheath 10 to its working position distal thereto, the compartment 18' expands to increase in volume up to a maximum volume, while the compartment 18 "contracts to decrease in volume up to a minimum volume.

In doing so, the user is to oppose the vacuum present in compartment 18', which ensures that the same force will always be required to open sliding door D, regardless of its position. At the same time, the compartment 18 "discharges the air present therein into the external environment.

Once the user has the door D in the open position, the vacuum present in the compartment 18' will suck the rod 20, automatically returning the tip 22 towards the rest position proximal to the sheath 10, returning the tip cylinder 21 against the end cap 12 and automatically closing the sliding door D. Thus, the compartment 18 "will be filled with air from the outside environment.

Due to the fact that the compartment 18' is considered empty, the linear actuator 1 guarantees constancy of the force required to open/close the door D from its position.

It is also evident that the linear actuator 1 is extremely functional and that its construction and assembly are simple and economical.

In fact, the assembly will take place as described above: the rod 20 is inserted via the tubular element 11, the end cap 12 is screwed at the end 13 'of the tubular element as mentioned above to obtain the compartment 18' under vacuum, and the closing element is screwed in correspondence with the opposite end 13 "after the closing element 14 is inserted on the end 22 of the rod 20 via the opening 15.

The assembly will then be completed by: the elastic diaphragm 24 is mounted on the rod 20 and inserted into the seat 26, the axial movement of which is blocked by means of a stop ring 25, which may be, for example, a Seegerring.

Since the number of constructional components is minimal, such as those in reciprocal movement, the linear actuator will require minimal maintenance and will ensure a long service life.

The linear actuator 1 has a minimum of dimensions, making it suitable for any application, such as moving sliding doors or sliding door leaves, as better described below.

The simplicity of the linear actuator 1 will always ensure automatic closing/opening of the door or door leaf from the open/closed position.

In a preferred but not exclusive embodiment of the invention, the closing element 14 may comprise means for controlling the inflow/outflow of the air flow from the variable volume compartment 18 "to control the force required to open the shutter D and/or its closing speed.

It is understood that the control means may also be configured for only one of the above mentioned functions, and in particular for controlling the force required to move the cylindrical element 21 from the rest position to the working position or controlling the speed of pumping the cylindrical element towards the closed position, without thereby going beyond the scope of protection of the appended claims.

To this end, generally speaking, first and second lines may be provided for fluidly connecting the variable volume compartment 18 "with the external environment and the valve member acting thereon.

In the embodiment shown in fig. 1a to 5, the first fluid connection line may be defined by the through opening 15 and a portion of the duct 19.

In this fluid connection line, when the terminal cylinder 21 is moved from the rest position to the working position, the air present in the compartment 18 "will pass through the through opening 15, enter the duct 19 via the opening 19" and exit via the outlet 19'. It is clear that when the terminal cylinder 21 is sucked from the working position to the rest position, the air will perform a reverse movement, entering via the opening 19' to reach the expansion compartment 18 ".

On the other hand, the second fluid connection line may be defined by the opening 15, the seat 26 and the annular gap 27 between the stop ring 25 and the rod 20.

In this fluid connection line, when the terminal cylinder 21 is moved from the rest position to the working position, the air present in the compartment 18 "will reach the outlet 27 when moving through the through-going 15 and the seat 26, while when the terminal cylinder 21 is sucked from the working position to the rest position, the air will make a reverse movement, entering via the annular gap 27 to reach the expansion compartment 18".

The valve means can be defined by an abutment 26 which will act as a valve abutment for the axial movement of the elastic diaphragm 24 which will act as a plug for the through-going 15 when the end cylinder 21 is sucked from the working position to the rest position and will abut against the stop ring 25 when the end cylinder 21 is moved from the rest position to the working position, in any case allowing the air flow.

In other words, during opening of the shutter D, the air present in the constricted compartment 18 "will pass freely through the duct 19 and the annular gap 27, whereas during closing of the shutter D, the air will pass exclusively through the duct 19 to reach the expanded compartment 18".

By appropriately dimensioning the above components, it will be possible to control both the force required to open the sliding door D and its closing speed. In particular, the force required to open the sliding door D can be determined by the diameter of the end cylinder 21.

In order to adjust the diameter of the end cylinder, suitable adjustment means, such as adjustment particles 30, may be provided for adjusting the flow cross section. In this way, it will be possible to adjust the inflow of air into duct 19 via opening 19' when drawing terminal cylinder 21 from the working position to the rest position, thus adjusting the speed of return to the closed position of shutter D.

For this purpose, the conditioning particles 30 can have a control end 31' accessible from the outside by the operator and a working end 31 ″ acting in the duct 19.

It is understood that the control member described above may be applied to any linear actuator, preferably of the pneumatic type, without thereby departing from the scope of protection of the appended claims.

For example, the above-mentioned control means may be applied to, or may comprise, gas springs of known type.

In another embodiment of the linear actuator 1, as shown for example in fig. 6 and 7, the rest position of the tip 22 may correspond to a position distal to the sheath 10, as shown for example in fig. 6, while the working position of the tip 22 may correspond to a position proximal to the sheath 10, as shown for example in fig. 7.

In this embodiment, the compartment 18 "may be fluidly isolated and vacuum, while the compartment 18' may be fluidly connected to the external environment to remain at atmospheric pressure.

For this purpose, when the end 22 is in the rest position, the end cylinder 21 of the rod 20 can abut against the closing element 14, and in particular against the stop wall 14' of the closing element, whereas when the end 22 is in the working position, the end cylinder 21 of the rod 20 can remain spaced from the bottom wall 16 of the end cap 12 to clear the opening 19 "of the duct 19.

In this way, the volume and pressure of the compartment 18 "are substantially zero when the tip 22 is in the rest position.

This embodiment will work in reverse of the embodiment shown in fig. 1 b-5, and therefore will work in compression rather than traction.

In fact, once the user has compressed the rod 20 from the extended rest position towards the retracted work position, the compartment 18 "will suck the same rod, bringing it back to the rest position.

Fig. 10 to 13B show other embodiments of the linear actuator 1, which can be used in the opening/closing system 100 described above.

More specifically, these embodiments are particularly suitable for the sliding movement of a closing element D having a limited length, such as a door of a refrigerated cabinet or a door of a shower cubicle.

Even though in the remaining description the linear actuator 1 is described for moving a sliding door leaf D, it is understood that the linear actuator 1 may have any use without departing from the scope of protection of the appended claims.

As mentioned above, in the description of the invention, the concept of sliding of the rod 20 with the sheath 10 and the counter-part must be understood in an opposite, rather than absolute, manner. Thus, even if for the sake of simplicity it is proposed that the rod 20 slides with respect to the sheath 10, it must be understood that the sliding of these parts is reciprocal and with respect to each other.

As is apparent from fig. 10 to 13B, the embodiment of the actuator 1 shown therein may have the same various characteristics as the embodiment shown in fig. 3 to 7.

Accordingly, unless otherwise specified, it is intended that the features described above with respect to the embodiments shown in fig. 3 through 7 also exist in the embodiments of fig. 10 through 13B.

As better specified in the rest of the description of the invention, these last embodiments differ from the embodiments shown in figures 3 to 7, in that there are movement promoting members 40 of the lever from the working position to the rest position and pneumatic or hydraulic damping members of this movement.

In the embodiment shown in fig. 11A and 13A, the linear actuator 1 is in a rest position, which may, but need not, correspond to a closed door leaf D position.

On the other hand, in the embodiment shown in fig. 11B and 13B, the linear actuator 1 is in the working position, which may, but need not, correspond to a fully or partially open door leaf D position.

As mentioned above, in the embodiment of fig. 10-13B, the linear actuator 1 may include a motion-promoting means, such as a resilient element 40 and more specifically a coil spring, operatively connected with both the sheath 10 and the rod 20 to return the tip 22 from the distal position to the proximal position when the tip moves from the proximal position to the distal position.

It should be understood that even if in the remaining description of the invention reference is made to the elastic element 40 and more precisely to the coil spring, the linear actuator 1 may comprise any movement promoting means, for example hydraulic, magnetic or pneumatic, without thereby departing from the scope of protection of the appended claims.

In a preferred but not exclusive embodiment, the rods 20 may be internally hollow, with the tubular wall 230 defining an internal chamber 240 in which the coil spring 40 may be housed.

There may also be means for operatively connecting the coil spring 40 to the same sheath 10 and rod 20 (e.g. respective threaded elements 160 and 250), respectively.

Threaded element 250 may be threaded into rod 20 at end 22, and threaded element 160 may be threaded into sheath 10 at end 13'.

It will be appreciated that in the embodiment of the linear actuator 1 shown in fig. 11A and 11B, the threaded element 160 may be screwed into the hollow cap 170, into the sheath 10 to provide a valve body, as better shown further.

On the other hand, in the embodiment of the linear actuator 1 shown in fig. 13A and 13B, the threaded element 160 can be screwed directly into the sheath 10 by means of its radially expanded portion 160'. It is obvious that also in this case the threaded element 160 can be made in several pieces, as for example in the embodiment of fig. 4A and 4B.

In this way, the sliding of the tip 22 from the proximal position to the distal position will correspond to the loading of the spring 40, which will return the same tip 22 towards the rest position.

By suitably selecting the relative dimensions of the threaded elements 160, 250 and the spring 40, it will be possible to mutually fix them in a simple and effective manner, so that the linear actuator 1 is extremely easy to mount.

In this case, in fact, it will be possible to screw the ends 41' and 41 "of the spring 40 onto the elements 160 and 250, while ensuring a long-lasting fixation.

Independently of the presence or absence of the coil spring 40, in the embodiment of fig. 10 to 13B, the sheath 10 may comprise a damping member acting on the rod 20 to damp the movement of the tip 22 when it moves from the distal position to the proximal position.

In the embodiment shown in fig. 10 to 11B, the damping member may be of a pneumatic type, while in the embodiment shown in fig. 12 to 13B, the damping member may be of a hydraulic type.

In any case, the damping member may comprise a working fluid located in at least one of the variable volume compartments 18', 18 ". Thus, regardless of its nature, the working fluid will act on the rod 20 to dampen its movement.

In particular, in the embodiment shown in fig. 10-11B, a pneumatic working fluid, in particular ambient air, is drawn into the compartment 18' as the tip 22 moves from the proximal position to the distal position.

The compartment 18' is then expanded by filling with air, while the other compartment 18 "will contract and expel the air present in the external environment through the opening 15. In order to obtain a damping effect, the two compartments 18', 18 "may be isolated from each other, i.e. not in fluid communication with each other. On the other hand, each of the two compartments 18', 18 "may be in fluid communication with the external environment.

Then, as the tip 22 moves from the distal position to the proximal position, air will be expelled from the compartment 18' in a controlled manner so as to obtain a damping effect.

In the embodiment shown in fig. 12-13B, a hydraulic working fluid, in particular oil, fills the entire sheath 10 and is transferred from compartment 18 "to compartment 18' as the tip 22 passes from the proximal position to the distal position.

Thus, the compartment 18 'will expand by filling with oil, while the other compartment 18 "will contract by draining the oil originally present in the same compartment 18'. In order to obtain a damping effect, the two compartments 18', 18 "may be in fluid communication with each other.

Then, as the tip 22 moves from the distal position to the proximal position, the oil will be expelled from the compartment 18' in a controlled manner to be transferred into the compartment 18 "in order to obtain a damping effect.

To achieve controlled discharge of the working fluid, suitable control means may also be provided which may comprise a cylindrical valve element 260 in the case of the hydraulic working fluid embodiment shown in fig. 12 to 13B or valve member 50 in the case of the pneumatic working fluid embodiment shown in fig. 10 to 11B.

In particular, with reference to the pneumatic embodiment shown in fig. 10 to 11B, the valve member 50 may comprise a valve body formed by a threaded element 160 and a hollow cap 170, which may present a first opening 51 implemented in the end cap 53 in fluid communication with the external environment via the openings 52', 52 "and a second opening 54 in fluid communication with the compartment 18' via the two openings 55', 55".

This embodiment of the valve body is particularly advantageous because, in practice, the threaded element 160 is an integral part of the same valve body and is the means for securing the coil spring 40.

In the openings 51, 54, a through bolt 56 is slidably inserted, so that between each opening and the same bolt 56, a calibrated hole is defined, suitably sized to define a damping effect. In this way, by appropriately selecting the relative dimensions of the plug 56 and the openings 51, 54, it will be possible to vary the damping effect.

The latch 56 is free to pass through the openings 51, 54 to protect it from foreign objects or dust.

A plug 57 may also be provided in the valve body, movable between a first operating position, shown for example in fig. 11B, remote from the opening 51, in which the extension of the flow section of the oil entering the compartment 18 'may be greater than the extension of the flow section of the oil coming out of the same compartment 18' defined when the plug 57 is in a second operating position, shown for example in fig. 11A, in which it is in contact with the first opening 51.

On the other hand, with reference to the embodiment of oil shown in fig. 12 to 13B, the cylindrical valve element 260 can be inserted onto the stem 20 so as to slide freely and tightly along the axis X.

In particular, as the cylindrical valve element 260 moves along the axis X, it can come into contact with the stop ring 270 and the end cylinder 21 mounted on the tubular wall 230.

More specifically, as the tip 22 moves from the distal position to the proximal position, the cylindrical valve element 260 can come into contact with a stop ring 270 to be pushed toward the tip 13', as shown, for example, in fig. 13A.

On the other hand, upon reverse movement, the cylindrical valve element 260 may come into contact with the tip cylinder 21 to be pushed toward the tip 13", as shown, for example, in fig. 13B.

During this movement, the cylindrical valve element 260 will determine the resistance of the tip 22 to movement in both directions, i.e. for example the resistance felt by the user during opening of the door leaf D or the resistance against its closing.

For this purpose, along the tubular wall 230, a first port 28 'and a second port 28 "can be provided, the second port being substantially larger in size than the first port, both interposed between the stop ring 270 and the tip 22 and between the same stop ring 270 and the distal tip 13', respectively.

Both ports 28 'and 28 "may be in fluid communication with compartment 18" and compartment 18' via the interior chamber 240 of the stem 20.

During movement of the cylindrical valve element 260, the stop ring 270 prevents the same cylindrical valve element 260 from reaching the port 28' so that it is always free.

On the other hand, when the tip 22 is moved from the distal position to the proximal position, the stop ring 270 will push the cylindrical valve element 260 to selectively cover the port 28", as shown, for example, in fig. 13A.

Thus, during this step, the oil can pass exclusively through the port 28', which has an extremely small size, which will provide a small flow section and a corresponding high resistance of said oil.

On the other hand, during reverse movement, oil may pass through both ports 28', 28", thus providing a much larger oil flow cross section and thus a corresponding minimum resistance.

By appropriately dimensioning the ports 28', 28 "and appropriately spacing them from the cylindrical valve element 260, it may be possible to vary the damping effect of the actuator 1.

Also in this case, to minimize overall size, the spring 40 may be placed in the interior chamber 240 of the stem 20.

From what has been described above, it is apparent that the invention achieves the intended objects.

The invention is susceptible of numerous modifications and variations, all of which are within the inventive concept expressed in the appended claims. All the details may be replaced with other technically equivalent elements and the materials may differ according to requirements without departing from the scope of the invention.

While the invention has been described with particular reference to the accompanying figures, the reference numerals used in the description and claims are used to improve the understanding of the present invention, and do not constitute any limitation on the scope of the protection claimed.