EP2651264A1

EP2651264A1 - Device for active ventilation of a seat

Info

Publication number: EP2651264A1
Application number: EP11819151.9A
Authority: EP
Inventors: Michal Sorm
Original assignee: Individual
Current assignee: Individual
Priority date: 2010-12-13
Filing date: 2011-12-08
Publication date: 2013-10-23
Also published as: WO2012079546A1

Abstract

A device for active ventilation of a seat arranged on a lower portion (1) of the seat having a seat part (2) movably mounted on a bearing member (12) and being air permeable at least in the region of a ventilated area (21), comprising as essential features at least one blade (3), rotatably mounted on the seat part (2) or on the lower portion (1), which blade is kinematically associated with the seat part (2) or the lower portion (1) of the seat in such an arrangement that the rotation axis (32) of the blade (3) is situated closer to the point of action (221) of the force exerted by an actuating element (22), kinematically associated with the seat part (2), than to the point of gravity of the area (33) of the blade (3). According another alternative embodiment the seat part (2) is rotatably mounted about at least one rotary axis 01 on the bearing member (12), the ventilation chamber (4) is limited by one movable wall (3), which movable wall (3) is rotatably coupled to the end of a longer arm of a single-armed or two-armed transmission lever (35) rotatably mounted on the lower portion (1), whereby the end of a shorter arm of the transmission lever (35) is directly or by means of a kinematic link coupled to the seat part (2).

Description

Device for active ventilation of a seat TECHNICAL FIELD

The invention relates to a device for active or forced ventilation of seats designed for furniture and transport means.

DESCRIPTION OF PRIOR ART

It is generally known that in the recent time the persons executing sedentary work are susceptible to increased health discomfort.

Other medical problems occurring with the persons executing sedentary work, specifically with men, is the overheating of the organism in the crotch area, which may result in reduced performance and consequently increased unease and even in decreased reproduction capacity. Many manufacturers resolve this by available means as well. The working chairs are fitted with maximum air permeable materials which enable to partially eliminate such a situation. But since the air wormed up by the sitting person tends to move upwardly, such natural circulation is obstructed by the body of the sitting person and therefore said problem may not be resolved by application of specific materials to the seat part. The only solution of this situation resides in applying forced air circulation by which the wormed up air is replaced by a colder air to establish in this way the thermal comfort. The forced circulation does not require a separately cooled air since the air to be replaced is wormed up to 36 °C and the required effect may be attained by the ambient air with the supposed temperature from 20 to 30 °C. The manufacturers have begun to solve this problem and specifically in the car industry certain solutions have been already applied. For example DE102009013257 discloses a solution residing in incorporation of small fans into the upholstered seat, where the fans promote forced air circulation under the sitting person. US 2006273646 brings a solution according to which a temperature controlled air is introduced inter the seat by an external ventilator. Although the above described and other similar solutions are efficient, they may be effectively applied to the seats used in automobiles, which do not encounter such problems as a connection to an energy source or air distribution system. For solitary situated furniture items, such systems are less appropriate. For example JP2271807 teaches a solution according to which an external vacuum pump is connected to a working l chair to provide air circulation. However, the mobility of seating is thus reduced. Other generally known solutions reside in the principle under which the sitting person alternatively loads and unloads the sitting area by flexibly deforming certain areas of the seat part. The seat part is provided by small elastic chambers, which when loaded deliver the air contained therein and when unloaded draw in new air to accomplish air circulation. A disadvantage of such a design is that the volume of the replaced air is equal to the volume reduced by the deformation of chambers. In order to preserve sufficient comfort of the sitting person said deformation is too small to satisfy required air replacement. The same disadvantage of a small volume of the replaced air is inherent in the solution according to CN1745682 by which a rigid, vertically movable and spring supported seat is connected to a chamber of variable volume. Upon loading the seat by the sitting person, the springs are pressed down and the seat part presses downwardly the chamber along the same distance to deliver the air into the seat part. For avoiding the effects of various weight categories, the springs and the chamber shall dispose of an adequate vertical reserve for its operating path, to prevent permanent compression of the chamber by heavier users. For this reason, an arrangement of the chambers in series above each other in order to increase the volume of the air replaced is impossible since the structural high of such a seat would become esthetically unacceptable for practical purposes.

The object of the present invention is to provide a device which is not susceptible to differences in weight of sitting persons, which does not require external energy source or external air supply and which exploits the movements of the seat part for a transmission controlled driving a blade or a rigid movable wall. Another object of the invention is to provide such an arrangement of ventilation chambers and blade drive that upon even minimum deviation of the seat part from the equilibrium position many times higher volume of the replaceable air is available than according to the known solutions.

SUMMARY OF THE INVENTION

The above discussed drawbacks are overcome and said objects are accomplished by a seat with a forced air ventilation according to the preamble of the first patent claim comprising as essential features a seat part permeable at least at the ventilated areas, and is movably mounted on a lower portion and which upon change of the center of gravity of the sitting person is tilted or displaced from the equilibrium position and through a kinematic link brings in motion a blade or similar device which transports a colder air surrounding the seat into the wormed up and ventilated areas of the seat part contacted by the sitting person or optionally draws the wormed up air from such areas.

Such design enables to ensure thermal comfort of the seat by exploiting actual weight of the sitting person only and by changing the center of gravity of the sitting person. A satisfactory thermal comfort may be reached by execution of only few cycles per hour what complies with the determined purpose of the movable seats for healthy seating and prevention from adverse affecting the human motion apparatus.

It is advantageous if the seat part is movably mounted on the lower portion with the possibility to deviate from its equilibrium position and by deviation from the equilibrium position to actuate through its actuating element a blade. Such blade is rotatably mounted at a point situated closer to the rotary axis of the blade than to the center of gravity of the blade effective area. Such configuration enables to make use of even a small change of the position of the seat part due to the change of the center of gravity of the sitting person for a great change in the position of the blade. This dependency is directly proportional to the distance of the actuating element and the center of gravity of the blade area from the rotary axis of the blade (lever arms - lever transmission).

It is also advantageous if the blade is rotatably mounted under the seat part and its operating path is situated in the free space or inside a half-open chamber. Such arrangement enables to make use of a solution, which is very simple in respect of the manufacturing process.

It is useful, if certain parts of the chamber are integrated into the seat part and the pedestal. Such arrangement makes possible to make use of a solution, which is simpler in respect of the manufacturing process.

It is further advantageous if the blade is rotatably mounted under the seat part and its operating path is situated inside a closed chamber provided with valves. Such a structure enables to increase the efficiency of individual working cycles of the device since the most of the volume of the air in the chamber, except for leakage loss, is supplied to the desired location.

It is useful if the blade is coupled to a chamber which has a form of a compressible below of a variable volume and which is provided with valves. This design enables to substantially increase the efficiency of individual cycles since the leakage loss is avoided and higher air discharge pressure may be applied.

It is also beneficial if the chamber has a form of a compressible below of a variable volume with a movable wall constituted by a blade. A single blade may operate in two chambers whose suction and discharge action is effected in the reverse order. Such embodiment makes also possible to substantially increase the efficiency of individual working cycles of the device and confers also a structural advantage.

The above discussed drawbacks are furthermore overcome and said objects are accomplished by a device for forced ventilation of a seat part according to the preamble of the sixth patent claim comprising as essential features a seat part rotatably mounted about at least one rotary axis 01 on a bearing member, a ventilation chamber limited by one movable wall, which movable wall is rotatably coupled to the end of a longer arm of a single-armed or two-armed transmission lever rotatably mounted on a lower portion of the seat, whereby the end of a shorter arm of the transmission lever is directly or by means of a kinematic link coupled to the seat part.

Such structure makes possible that a relatively small tilting motion of the seat part from the equilibrium position causes, due to the application of the transmission lever, relatively long motion of the rigid movable wall of the ventilation chamber and consequently a great change in its volume when compressed or expanded. This solution makes a large volume of the drawn in and delivered air available for ventilation of the seat part.

It is also advantageous, when the ventilation chambers are arranged on either side of the rotary axis 01 , where each of the ventilation chambers is limited by one wall movable in vertical direction and attached along its perimeter to deformable peripheral walls, whereby the rigid movable wall is rotatably coupled to the end of the longer arm of the respective transmission lever. Such structure enables formation of greater number of ventilation chambers in the space between the seat part and the lower portion of the seat, which chambers are operated by tilting motion of the seat to various directions, for example back and forth, to the left and to the right.

Further, it is useful if the rigid movable wall is rotatably coupled on both its opposite lateral edges to the ends of the longer arms of the transmission lever for tilting about the axis 03.

This structure provides for reliable displacement of the movable wall of the ventilation chamber by means of a pair of transmission levers.

It is also suitable if the kinematic link is formed as a vertical actuating element exposed to tensile and compressive stress.

Such a structure is preferably applicable to the seat parts made of inflexible material, the lateral edges of which are coupled to the upper ends of the vertical actuating elements and the lower ends of which are coupled to the transmission levers.

It also useful if the kinematic link is constituted by a balance beam secured to a pivot at its central point, which pivot is rotatably mounted on the bearing member, whereby the seat part is secured to the pivot and the upper ends of the actuating elements are coupled to the ends of the balance beam.

This structure is preferably applicable to the seats made of a slightly flexible material, the edges of which, when loaded by a heavier person, bend downwardly and the actuating elements, and consequently the transmission levers, also moves downwardly without causing any tilting motion of the seat part.

It is further advantageous if the upper part of the bearing member is formed as bearings for rotatable mounting the pivot or pivots of the tilting seat part.

Such structure is most simple from the technological point of view.

It is also useful if the actuating element has a form of a connecting rod.

Such embodiment ensures reliable transmission of both the compressive and tensile forces from the seat part to the transmission lever controlling the delivery and drawn in motion of the rigid movable wall in the ventilation chamber. It is also suitable if the pairs of transmission levers disposed on both the left and the right half portions of the seat are mutually fixedly connected by a shaft situated in the rotation axis 02 of the levers.

This configuration results in saving of one balance beam and two actuating elements for controlling the transmission levers.

According to another advantageous embodiment, the movable wall is constituted by a separation wall placed between two sectors of the ventilation chambers arranged above each other.

Such structure enables formation of two sectors of ventilation chambers situated above each other whereby the changes of their volumes are produced by movement of only one rigid movable wall.

Further it is also advantageous if the axis of the rotatable coupling of the movable wall to the transmission levers is identical with a neutral axis of the moment of inertia of the rigid wall.

Such embodiment ensures substantially horizontal position of the rigid movable wall upon its forcible movement.

BRIEF DESCRIPTION OF THE DRAWINGS

Certain embodiments of the invention are schematically illustrated by way of accompanied drawings. For the sake of clarity, certain figures fail to show springs, valves or optionally air piping or distribution systems. In the drawings:

Fig. 1a shows a 1^st alternative embodiment in the equilibrium position;

Fig. 1b shows the 1^st alternative embodiment in the position at maximum tilting angle;

Fig. 2a shows a 2^nd alternative embodiment in the equilibrium position;

Fig. 2b shows the 2^nd alternative embodiment in the position at maximum tilting angle;

Fig. 3a shows a 3^th alternative embodiment in the equilibrium position;

Fig. 3b shows the 3^th alternative embodiment in the position at maximum tilting angle;

Fig. 4 shows an orifice plate in neutral position;

Fig. 5 shows a cross-sectional view of the 5^th alternative embodiment of the seating device with the seat part in equilibrium position;

Fig. 6 shows a cross-sectional view of the 5^th alternative embodiment of the seating device with the seat part in a tilting position; Fig. 7 is a perspective view of the doubled ventilation chamber;

Fig. 8 is a detail of Fig. 5 on large scale;

Fig. 9 is a schematic view of the 6^th alternative embodiment of the seating device.

DETAILED DESCRIPTION OF THE EMBODIMENTS 1^st alternative embodiment

Figures 1a and 1 b show a 1^st alternative embodiment of the invention, where the seat part 2 is rotatably mounted on a bearing member 12 of a pedestal of a lower portion 1. In this embodiment, the bearing member 12 is a radial bearing 121 (or it may have a form of a ball journal or a trust swing bearing, etc.) with the orientation in the direction of the possible tilting action of the seat part 2 to the left or to the right side of the sitting person (optionally with a backward or forward orientation). A half-open chamber 41 is located between the seat part 2 and the lower portion 1. This chamber is constituted by a directing board 11 , lower portion 12 and the wall 24 of the seat part 2, which only directs the flow of the air to a ventilated area 21 of the seat part 2. An actuating element 22 is secured to the seat part 2 or is incorporated in the seat part 2 (as a boss or projection).

Upon tilting motion of the seat part 2 from its equilibrium position, the actuating element 22 actuates a blade 3 by an impulse of force at a point of action 221 close to the rotation axis 32. The blade is constituted by a large thin plate and is coupled to the lower portion 1. By the effect of impulse of force, the blade 3 is caused to slightly tilt about its rotation axis 32 so that its point of gravity carries on a longer path than the actuating element 22 of the seat part 2. In this way the blade 3 draws off the air under the seat part 2. When returning to the starting position by the force of a non-shown spring, the blade discharges a fresh air through the half-open chamber 41 to the ventilated area 21. The blades 3 with non-shown springs, the actuating element s 22 and the half-open chambers 41 are installed on either side of the tilting seat part 2 and operate in reverse order. Fig. 1 a shows the equilibrium position, where both the blades 3 take the position of their upper dead center, Fig. 2b illustrates the position of the seat part 2 at the maximum tilting angle to the left side with the left air blade 3 at the bottom dead center . 2 alternative embodiment

Figures 2a and 2b show a 2^nd alternative embodiment of the invention, where the seat part 2 is supported by the bearing member 12 of the lower portion 1. In this embodiment, the tilting action of the seat part 2 is effected by a set of tilting props 122 arranged in the way of parallelogram and enabling the tilting of the seat part 2 to the left or right side of the sitting person (optionally with a backward or forward orientation). The seat part 2 is provided with the actuating element 22 (a projection or boss), which, when the seat part 2 is shifted laterally, applies pressure on the second arm of the blade 3 at the point of action 221. The blade 3, which is rotatably mounted on the lower portion 1 turns slightly about its rotation axis 32 and with this motion the blade 3 discharges air from the stabile fixed chamber 4 into the distribution system 6 through a discharge valve 5 which is directed to the ventilated area 21 of the seat part

3. At the same time a fresh air is drawn in from the other side of the blade 3 through an inlet valve 51 to the second sector of the chamber 4. The chamber 4 has a wedgelike shape and is limited by immovable walls 44 of a solid material and its internal dimensions correspond to the motion trajectories of the marginal points f the blade 3. The blade 3 moving inside the chamber 4 divides the chamber 4 into two sectors of a variable volume each of which is provided with an inlet valve 51 and is connected to the air distribution system 6 including the discharge valve 5.

When the seat part 2 returns to the equilibrium position due to the movement of the sitting person, the blade returns to its starting position by action of a non-shown spring to deliver the drawn in fresh air from the chamber 4 to the distribution system 6 and through the discharge valves 5 to the ventilated area 21. The blades 3 of the chamber

4, discharge valves 5, inlet valves 51 and air distribution system are installed in pairs under the seat part 2 on both the left and the right side of the seat part 2 in reverse order. Fig. 2a illustrates the equilibrium position, where both the blades 3 are situated at their bottom dead center . Fig. 2b illustrates the position with the maximum deviation of the seat part 2 to the left side, where the left blade 3 is in its upper dead center. On the blade 3 the center of gravity 31 is shown whose calculated position is significant for the calculation of the transmission of the impulse of force produced by the seat part 2 to the impulse of force produced by the blade 3 with respect to the air.

3^th alternative embodiment

Figures 3a and 3b show another alternative embodiment of the invention, where the seat part 2 with the ventilated area 21 is mounted on the bearing member 122 of the pedestal of the lower portion 1. In this embodiment, the bearing member 12 has the form of a ball journal 124 ( optionally of a radial or trust swing bearing). The actuating element 22 is secured to the seat part 2 and the blade 3 is rotatably mounted on the actuating element 22. When the seat part 2 deviates from its equilibrium position, the actuating element 22 exerts a force impulse to the blade 3 at the point of action 221. and the blade 3 rotates about its rotation axis 32 from the bottom dead center to the upper dead center. At the area of its rotation axis 32, the blade 3 is supported by a retaining edge 13 of the lower portion 1. Deformable peripheral walls of the chamber 4 of variable volume are attached to perimeter of the blade 3. The immovable solid chamber walls 44 are attached to the lower portion 1 or to the seat part 2 respectively. Upon motion of the blade the air in the chamber 4 is discharged to the distribution system 6 through the discharge valves 5 directed to the ventilated area 21 and simultaneously, the previously compressed chamber 4' expands and draws the fresh air inside through the inlet valve 51. When the blade 3 is returning to its starting position by action of a non-shown spring, the actions of the chambers 4 and 4' are exchanged. The blades 3, chambers 4 and 4', actuating elements 22 and retaining edges 13 are installed in pairs under the seat part 2 in reverse order. Fig. 4a shows the equilibrium position, where the blades 3 are in their bottom dead center and Fig. 4b shows the situation with the maximum deviation of the seat part 2 to the right side, where the blade 3 takes its upper dead center position.

4^th alternative embodiment

Figure 5 shows an example of the embodiment provided with simple regulation of the air supply into the ventilated area 21 of the seat part 2. The ventilated area 21 is constituted by a system of ventilating holes 25 with the air flow rate regulated by a slidably mounted orifice plate 7. The orifice plate 7 has regulating orifices 71 whose size is identical with the size of the air vents in the ventilated area of the seat part 2. The sliding path of the orifice plate 7 is defined by guide bars 73. The displacement of the orifice plate 7 is actuated by the sitting person by means of a handle 72. In this way it comes to complete, partial or no overlapping the ventilating holes 25 with regulating orifices 71. The slidably mounted orifice plate 7 may be substituted by a rotatably mounted orifice gauge which structure is however more complicated. 5 alternative embodiment

As may be seen from the attached drawings 5 to 8, the seat consists of a seat part 2 provided at least in its central area with ventilating holes 25 to create a ventilated area 21 of the seat part 2. The seat part 2 is mounted for tilting motion about the rotary axis 01 on a rigid bearing member 12, which is connected to a lower portion 1 of a tub-like shape created by peripheral walls 11. Ventilation chambers 4, or bellows, of variable volume are displayed substantially symmetrically on either side of the bearing member 12. Their function is to draw in the ambient air by expanding their internal volume and to discharge the accumulated air by reducing their volume into an air permeable portion of the ventilated area 21. Each ventilation chamber 4 is limited by a single, substantially horizontally situated rigid movable wall 3, which is attached along its perimeter to deformable peripheral walls 43. In the illustrated embodiment, the peripheral walls 43 are attached to the perimeter of the rigid immovable wall 44, which is located opposite the rigid movable wall 3. As shown in the illustrated examples, the ventilation chambers 4 are disposed on either side of the bearing member 12, i.e. on its left side and its right side. As shown in Fig. 7, each ventilation chamber is divided by the rigid movable wall 3 into upper and lower sector. The immovable wall 44 of the lower sector of the ventilation chamber 4 is attached to the bottom of the lower portion 1 and the immovable wall of the upper sector of the ventilation chamber 4 is attached to the upper part of the peripheral walls 11 of the lower portion 1. The ventilation chambers 4 are connected to the atmosphere by suction holes provided with inlet valves 51 and by means of discharge valves 5 to the space under the ventilated area 21 , either directly or by means of an air distribution system 6. Advantageously, both the inlet valves 51 and discharge valves 5 may be formed as flaps. Both the inlet and discharge valves are incorporated in the immovable rigid walls 44. The movable wall 3 is on its lateral opposite edges rotatably coupled to a longer arm of a respective transmission lever 35. The outer ends of both the single-armed levers 35 arranged in pairs are rotatably mounted about a rotation axis 02 on the lower portion 1 , specifically on its upwardly directed peripheral wall 11 if the lower portion 1 has the tub-like shape. Adjacent to the outer end or the rotation axis 02, i.e. on its shorter arm, the transmission lever 35 is coupled with the substantially vertically disposed actuating element 22. The upper end of the actuating element 22 is coupled to the seat part 2 at the point close to the edge of the seat part 2, which upon the tilting motion of the seat part 2, performs a relatively long movement in vertical direction. The closer the lower end of the actuating element 22 is coupled to the outer end of the transmission lever 35, or to its rotation axis O2, i.e. the shorter is the arm, the longer displacement of the movable wall is achieved upon the motion of the actuating element 22. In the present example, the actuating element 22, which is exposed to both the tensile and compressive stress is in the form of a connecting rod but according to the invention it may take another form, for example of a little rigid but still flexible element capable to transfer the tensile and compressive stress even when slightly deflected.

According to Fig. 5, the seat part 2 loaded by a (not shown) sitting person is in its equilibrium horizontal position. The transmission levers 35 and the rigid movable walls 3 take also approximately horizontal position. The upper and lower sectors of the ventilation chamber 4 contain approximately the same volume of the air previously drawn in. If the sitting person moves to the left side, its center of gravity is displaced and the seat part 2 tilts about the rotary axis O1 from the equilibrium position counterclockwise to the left side, as shown in Fig. 6. Consequently, the actuating elements 22 move the left transmission lever 35 downwardly and the right transmission lever 35 upwardly, whereby the left transmission lever urges the rigid movable wall 3 downwardly. Simultaneously, the air volume in the lower sector of the ventilation chamber 4 is discharged through the discharge valve 5 and the air distribution system 6 into the space under the ventilated area 21 and further over the ventilating holes 25 of the seat part 2 to the sitting person. At the same time, the volume of the left upper sector of the ventilation chamber 4 is forcibly expanded and the ambient atmospheric air is drawn in through the inlet valve 51 provided in the upper immovable wall 44. Simultaneously, air is drawn inside the lower sector of the ventilation chamber 4 on the right side of the seating device through the inlet valve 51 in the lower immovable wall 44 and the air collected in the upper sector of the ventilation chamber 4' is discharged through the discharge valve 5 of the upper immovable wall 44 in the space under the ventilated area 21. The space under the ventilated area 21 between the upper immovable walls and the seat part 2 is separated from the ambient atmosphere by a rubber seal 26. If the seating person moves to the opposite side, i.e. to the right, the seat 2 tilts clockwise to the right and the left actuating element 22 pushes the left transmission lever 35 upwardly. Simultaneously, the left movable rigid wall 3 moves upwardly and the right actuating element 22 tilts the right transmission lever 35 downwardly, while the right rigid movable wall 3 is shifted downwardly. The air in the left upper and the right lower sector of the ventilation chamber 4' is discharged to the ventilated area 21 and the ambient air is drawn inside the left lower and the right upper sector of the ventilation chamber 4. Accordingly, any change in the position of the seating person produces forced ventilation of the ventilated area 21 of the seat part 2 and improves the thermal comfort of the seating person.

The above-described 5^th alternative embodiment, where the actuating element 22 is coupled by its upper portion directly to the seat part 2, is suitable for rigid, substantially inflexible seat parts 2.

6^th alternative embodiment

When a less rigid seat part 2 is applied the marginal area of which may be, due a greater weight of the seating person, flexibly bent downwardly, it is not appropriate to couple the actuating elements 22 to the marginal area of the seat part 2 since both the transmission levers 35 could be moved downwardly until they engage a lower abutment point and consequently the tilting of the seat part 2 about the axis 01 and the movement of the movable walls would be disabled. In this event, the 6^th alternative embodiment, as schematically illustrated in Fig. 9, is more appropriate. Here, the medium rigid portion of the seat part 2 or a connecting flange of the seat part 2 is secured to a pivot 14, rotatably supported by a bearing of the bearing member 12. A balance beam 15 is secured at its central point to the end of the pivot 14, while the outer ends of the balance beam 15 are coupled with the actuating elements 22. If the front transmission levers 35 are connected to the rear transmission levers 35 by a shaft 36 along the rotation axis 02 then only one front balance beam with two actuating elements 21 may procure sufficient movement of the movable walls 3.

In order to avoid twisting of the immovable wall 3 of the ventilation chamber 4, i.e. to maintain it in approximately horizontal position, the coupling points for transmission levers 35 are created on the opposite edges of the immovable wall 3 in the neutral axis of the moment of inertia of the area of the movable wall 3. The axis of the rotatable coupling of the movable wall 3 to the transmission levers 35 is then identical with the neutral axis of the moment of inertia of the movable wall 3.

According to another possible embodiment, the bearing member 12 is constituted by bearings provided in the lateral walls of the lower portion 1 of tub-like shape and the pivots of the seat part 2 are supported by bearings.

The lower portion 1 of the seat is supported by a non-shown pedestal, which may be constituted by one central leg or more legs respectively. It is to be understood that according to the invention, the seat part 2 may be tilted about a number of rotary axes 01, for example laterally, forwardly or backwardly and in this way it may operate more ventilation chambers 4. It is also possible to create the transmission lever 35 as a two-armed lever having its shorter arm located opposite the longer arm with respect to the rotation axis 02. It is essential, that the tilting motion of the seat part 2 is transformed to the shorter arm of the transmission lever 35, which is rotatably mounted on the lower portion 1 and that the longer arm causes displacement of the movable wall 3 in the ventilation chamber 4.

Claims

1. A device for active ventilation of a seat arranged on a lower portion (1) of the seat having a seat part (2) movably mounted on a bearing member (12) and being air permeable at least in the region of a ventilated area (21),

characterized in that

at least one blade (3) is rotatably mounted on the seat part (2) or on the lower portion (1), which blade is kinematically associated with the seat part (2) or the lower portion (1) of the seat in such an arrangement that the rotation axis (32) of the blade (3) is situated closer to the point of action (221) of the force exerted by an actuating element (22), kinematically associated with the seat part (2), than to the point of gravity of the area (33) of the blade (3).

2. The device for active ventilation of a seat according to claim 1 , wherein the blade (3) is situated in a free space under the seat part (2) or in a half-open chamber (41).

3. The device for active ventilation of a seat according to claim 1 , wherein the blade (3) is situated in a solid closed chamber (4) provided with a discharge valve (5) and an inlet valve (51).

4. The device for active ventilation of a seat according to claim 1 , wherein the blade (3) forms a movable wall (41) of the chamber (4) of a variable volume or the blade (3) is connected to the movable wall (41).

5. The device for active ventilation of a seat according to claim 1 ,2, 3 and 4 wherein the chamber walls (44) of the chamber (4) or the half-open chambers (41) are incorporated into the lower portion (1) or the seat part (2).

6. A device for forced ventilation of a seat comprising a seat part (2) with at least one air permeable ventilated area (21) and arranged movably relative to a lower portion (1) of the seat on at least one bearing member (12) supported by the lower portion (1), whereby at least one ventilation chamber (4) of variable volume is located between the seat part (2) and the lower portion (1) to draw in the ambient air upon enhancing its volume and to discharge the draw in air upon reducing its volume to ensure ventilation of the ventilated area (21) of the seat part (2),

characterized in that

the seat part (2) is rotatably mounted on the bearing member (12) about at least one rotary axis 01 , the ventilation chamber (4) being limited by one movable wall (3) , which movable wall (3) is rotatably coupled to the end of a longer arm of a single-armed or two-armed transmission lever (35) rotatably mounted on the lower portion (1), whereby the end of a shorter arm of the transmission lever (35) is directly or by means of a kinematic link coupled to the seat part (2).

7. The device for forced ventilation of the seat according to claim 6 wherein the ventilation chambers (4) are arranged on either side of the rotary axis 01 , where each of the ventilation chambers (4) is limited by one movable wall (3) movable in vertical direction and connected along its perimeter to deformable peripheral walls (43) whereby the movable wall (3) is rotatably coupled to the end of a longer arm of the respective transmission lever (35).

8. The device for forced ventilation of the seat according to claim 7, wherein the rigid movable wall (3) is rotatably coupled on both its opposite lateral edges to the ends of the longer arms of the transmission levers for tilting about the axis 03.

9. The device for forced ventilation of the seat according to claim 6, wherein the kinematic link is formed as a vertical actuating element (22) exposed to tensile and compressive stress.

10. The device for forced ventilation of the seat according to any of the preceding claims 6 to 8, wherein the kinematic link is formed as a balance beam (15) secured to a pivot (14) at its central point, which pivot is rotatably mounted along the rotary axis (01) on the bearing member (12), whereby the seat part (2) is secured to the pivot (14) by its central portion and the upper ends of the actuating elements (22) are coupled to the ends of the balance beam (15).

11. The device for forced ventilation of the seat according to any of the preceding claims 6 to 10, wherein the upper part of the bearing member (12) is formed as bearings for rotatable mounting of the pivot (14) or pivots (14) of the seat part (2).

12. The device for forced ventilation of the seat according to any of the preceding claims 9 to 11 wherein the actuating element (22 has a form of a connecting rod.

13. The device for forced ventilation of the seat according to claim 10, wherein the transmission levers (35) disposed on both the left and the right half portion of the seat are mutually fixedly connected by a shaft (36) situated in the rotation axis 02 of the transmission levers (35).

14. The device for forced ventilation of the seat according to claim 8, wherein the rigid movable wall (2) is constituted by a separation wall placed between two sectors of the ventilation chambers (4,4") arranged above each other.

15. The device for forced ventilation of the seat according to claim 8 wherein the axis (O3) of the rotatable coupling of the movable wall (3) to the transmission levers (35) is identical with a neutral axis of the moment of inertia of the rigid wall (3).