VENTILATED BODY SUPPORT

Abstract: A body-supporting device forming the seat (1) and/or the backrest (15) of a chair and adapted to avoid sweating caused by the thermal insulation of the chair is characterized by the fact that at least those sections (2) of the exterior surface of the device that form the support surfaces for parts of the body of a person sitting in the chair are made of air-permeable material. At least one opening (11) to the exterior is arranged in said device to communicate with the interior side of said air-permeable sections (2). A suction device capable of producing a negative air pressure, such as a suction turbine, may be connected to said opening. The interior of the body-supporting device is so arranged that, when a suction device is thus connected and is running, air that is exterior to said support surfaces will be drawn through the air-permeable sections (2) and via the interior of the body-supporting device and out of it through said opening (11), in order to remove heat radiated by the body of the person, in particular from the region between said parts of the body and the air-permeable sections, and to cool the latter by means of the airstreams thus created.

Description: VENTILATED BODY SUPPORT FIELD OF THE INVENTION AND PRIOR ART This invention applies to a body-supporting device forming the seat and/or back rest of a chair, its purpose being to avoid sweating caused by the thermal insulation of the chair. The term "chair" is used to cover all types of furniture intended for sitting thererin, such as vehicle seats in all kinds of vehicles, office chairs and domestic arm chairs. This should be born in mind, as the invention is described below aε it would be applied to the driver's seat of a conventional vehicle. Every driver who has driven a car in hot weather, for example during the summer holiday period, has certainly experienced great problems with the sweating that takes place from those parts of the body that bear upon the driver's seat. This is because the chair, upon the body surfaces in contact with the chair, acts as an termal insulator substantially obstructing and reducing the capability of the body to emit heat by radia¬ tion. The consequence is that other parts of the body must contribute more to meet the requirements of the body to be cooled by heat radiation. To achieve this it is common to open one or more windows, which results in draughts and negative consequences for health and and has a very small positive influence. However, if the temperature in the car is high enough, the body cannot loose enough heat; by radiation without sweating. In this case the sweating will be particularly noticeable where the body is in cotact with the chair, aε an effective barrier to vapour diffusion is formed between the body and the support surfaces of the chair, making evaporation more difficult and causing these parts of the chair to become wet with sweat, which stick to shirts, trousers and other items of clothing and cause severe discomfort. This phenomenon occurs even if the seat covers are made of material that can "breathe", avoiding non-permeable material such aε leather. In order to avoid the above disadvantages a driver's seat incorporating ducts in which cold air is circulated by a pump connected to the chair has been proposed. It is true that the circulation of the cold air inside the chair makes an increase of the heat radiation of the body from those surfaces that are in contact with the chair possible, but in practical trials with this type of chair it was found that the solution was unusable: the test drivers found after driving a vehicle with a cooled chair for some hours that their backs had become so chilled that they were unable to rise from the chair without assistance. Accordingly, the chair in question had no future. BRIEF DESCRIPTION OF THE INVENTION The purpose of this invention is to construct a device of the type diεcuεεed above, which would make it poεsible to εit comfortably in a chair without the problems mentioned above of conventional chairs, but without any negative effects upon the health of the person sitting in the chair. According to the invention this purpose is achieved by provi¬ ding a device of the type defined in the introduction with the features defined in the characterizing part of the appended claim 1. A device according to the invention πa.es it poεεible to suck air through those support εurfaceε of me chair with which the body of a person sitting in a chair would be in contact, by which means sucked air will pass close to the contact surfaces of the seated person's body, thus cooling them in a comfortable way and keeping them dry. It has been found that in the device according to the invenntion the heat flow from those parts of the body forming the contact surfaces to the chair may be just as high aε if the perεon were freely standing up, the value of the heat flow beeing naturally dependent on the internal construction of the device and on the suction effect utilized of the suction device in use. Furthermore, the support surfaces of the device are capable of absorbing the sweat produced, if any, and moisture that may be produced between the body and the support surfaces, thus maintaining the support surfaces dry and cool despite of this thanks to the air stream passing. Other advantageous features of the invention and the advantages thereof will be made apparent in the following description of a preferred embodiment of the invention, and in the dependent claims, one being that several features have the purpose of achieving aε effective and aε localised a suction effect aε possible, thus utilising minimum effect in the suction device. BRIEF DESCRIPTION OF THE DRAWINGS With reference to the appended drawings, below follows a deεcription of a preferred embodiment of the device according to the invention cited aε an example. In the drawings: fig 1 is a sectional view of a preferred embodiment of the invention as applied to the seat of the driver's seat of a vehicle, in which the central porticr of the seat has been removed for clarity, fig 2 is a perspective view of a seat constructed according to the invention, in which external parts have been removed to illustrate some of the details of the interior of the device important for the function of the device according to the invention, and fig 3 is a perspective view of a driver's seat contructed according to the invention, compressed by the weight of a person seated on it, in which a section has been taken across the seat. DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION The following is a description of a body-supporting device which forms both seat and backrest of a chair, but it is quite possible that only the seat or only the backrest of a chair would be provided with such a device, if thiε were desirable. In the present case the chair is identical with the body-sup¬ porting device, and the shorter term may be used for the latter. Fig 1 εhows how the seat 1 of a chair is constructed according to the invention, the backrest being constructed in a corres¬ ponding way. The section 2 which form supporting εurfaceε for partε of. the body of a perεon sitting in the chair are made of an air-permeable material, preferably and in this example of wool. At the sides and the front of the seat, the wollen layer 2 is sewn onto an airtight layer 3, such as plastic or leather, which covers the sides and underside of the seat. The interior of the seat will now be described and to better illustrate hov the seat is constructed, the component partε shown in fig 2 are not depicted in their correct relative scale, and for gaining further clearness layers which in reality are superposed in close contact with each other have beer, εpaced apart. Immedia¬ tely beneath the wollen layer 2 iε = layer 4 with conducting circuits for electrical heating of rr.e εeat cushio . Beneath the electrical heating layer 4 is a εecond wollen layer 5, εimilar to the firεt one. The wollen layerε are preferably about 5 mm thick. The εecond wollen layer 5 is tightly con¬ nected to the airtight layer 3, so that all air penetrating through the outer wollen layer must pasε through the second wollen layer 5 in order to reach the interior of the seat. Beneath the second wollen layer 5 is a bag 6 of virtually airtight material. The bag, in this example, is made of an elastic sheet rubber material, perforated in the direction of the second wollen layer by a number of holes 7 with a diameter of preferably about 20 mm. The elastic sheet rubber material tightly encloses and is in close contact with elementε arranged in the bag. Immediately inside that εide of the sheet rubber material 6 that is directed towards the support surfaces of the seat is a firεt layer 8 of fibrous material,here a disc of horsehair. Beneath the horsehair layer 8 is arranged a porous body 9 of foamed plaεtic. The thickness of the foamed plaεtic body iε about 100 mm when not compressed. Beneath the foamed plastic body 9 is placed a εecond horεehair layer 10. The bag 6 haε an opening 11 close to the εecond horεehair layer 10 and towards the side of the seat, to which iε attached a preferably flexible tube 12 which protrudes from the εeat and iε connected to the negative pressure εide of a suction turbine 13 (εee fig 2). The function of the device deεcribed above will now be explai¬ ned. When the suction turbine 13 iε powered up it createε a negative preεεure at the opening 11 in the perforated sheet rubber material 6. The sheet rubber material is tightly bearing under tension against the εideε of the foamed plaεtic body, whereby the poreε cloεe to those εurfaceε of the foamed plaεtic body are sealed, so that no air car. arrive to the opening 11 without paεεing through the foamed plastic body 9. Both horse¬ hair layerε 8, 10 are permeable tc ai: . as iε the porous foamed plaεtic body 9 itself, and they have a tendency to distribute a concentrated negative air preεsure uniformly over a larger area. This fact and the action of the suction turbine create a negative air pressure substantially evenly distributed over the upper side of the porous body, aε indicated by the small arrows 14. This evenly distributed negative air pressure provides substantially the same suction effect at each of the holes 7 in the perforated sheet rubber material 6. Reference is now made also to fig 2. The holes 7 in the εheet rubber mateial are arranged in a pattern which substantially corresponds to the shape of the projection on the seat and the backrest of those parts of the body that would normally beat- thereupon. Thus the holes in the seat, εeen from above, are arranged in the form of a letter U, correεponding tc the extenεion of the tighε and buttockε of a person εitting ir. the chair. The εheet rubber material arranged for the backrest is perforated along a line εubstantially corresponding tc the spinal column of the person. The suction-equalising device formed by the perforated sheet rubber material and its contents causes substantially equal amounts of air to be drawn through the wollen layers 2 and 5 in the vicinity of each of the holes. Wollen layer 2 will spread the suction effect somewhat, εc that it iε applied to a larger area of the support surfaces of the seat and would correspond to a direct projection of the corre¬ sponding holes 7. The effect of this is that a coherent area corresponding to the support surfaces against which a perεon'ε thighε and buttockε bear will have air drawn through it. By thiε means, those parts of the body in contact with the seat will be cooled by the passage of the air and kept dry. A very good and appropriately large transport of heat from these contact surfaceε of the body can thereby take place. The εuction-equalising arrangement not only produce air streams evenly distributed over the relevant εurfaceε, but alεo enεureε by meanε of the diεpoεal of the holes " that the εuction effect iε limited tc theεe contact εurfaces . Through the latter fact εuction is avoided where it iε completely εuperfluouε, which makeε poεεible a great economy of power, so that the εuction turbine can run at a rate as low aε poεsible and be made aε silent as poεεible. Ideally, the noiεe made by the εuction turbine should not be audible by a perεon εitting in the chair. Thiε aim iε more easily achieved if a εuction turbine is mounted in the baggage space of the vehicle, but also other locations, such as in the engine compartment, are possible, if there is space. It should be noted, however, that the "noise" of the suction turbin is at such a low lewel that it could also be mounted in the εame air εpace, close to the chair. Prefe¬ rably, it should be possible to regulate the speed of rotation of the suction turbine, so that it can be adjuεted according to the conditionε, of temperature, clothing, etc. Fig 2 shows how the backrest 15 and seat 1 of a chair according to the invention each are composed by a suction-equalising device, and each device has an opening, through a .branching connected to the εame tube 12 leading to a suction turbine 13. It would also be poεεible, though hardly to be recommended, to conεtruct backreεt and εeat aε one piece, uεing the εame perforated, bag forming εheet .rubber material in the construc¬ tion of the backreεt aε well aε the εeat. Fig 3 εhowε how the εeat 1 will be compressed by the weight of the person εitting on it. It iε clearly εhown how the foamed plaεtic body 9 iε thereby deformed and also has a shock-absor¬ bing and comfort-enhancing funtion. The first horsehair layer 8 prevents those parts of the perforated εheet rubber material that are under compresεive load from making direct contact with the upper side of the foamed plastic body, which would other¬ wise seal the surface pores and cauεe an uneven diεtribution of negative air preεεure. The preεence cf the firεt fibrouε layer 8 iε therefore neceεεary, while it would be poεεible, though not recommended, to omit the second rirrouε layer 10. The plastic εheet rubber material bag is a very important feature of the present invention. It eliminates the need for air channels or tubes inside the chair. This is a great advantage, aε air channels can easily be closed by the loads exerted thereon by a person εitting in the chair, and air tubes seriously decrease the sitting comfort, so that it will be uncomfortable to sit in the chair for any length of time. The device according to the invention iε oεt uεeful at ambient temperatureε between 18 and 38 C: The invention iε not in any way limited to the preferred embodiment deεcribed above, but a man εkilled in the art εhould without difficulty be able to find out a number of poεεible odificationε, whithout thereby departing from the baεic idea of the invention. It would be poεεible, for example, to replace the suction turbine by any other suitable suction device. The electrical heating layer could be omitted if this was desirable, in which place only one w r ollen layer would be necessary. Although it has been found very advantageous to use wool as the air-permeable material for the support surfaces in question, it will be feasible to uεe any other material with εimilar proper- tieε.. The virtually airtight material enclosing the sides, underside and back of the chair could be omitted and replaced by an air-permeable layer, although it would then be advisable to retain a layer of such a virtually airtight material around the air-permeable portionε at leaεt in the region of said support εurfaceε in order to avoid suction of air from portions against which parts of the body of a person do not bear. The foamed plaεtic and the horεehair of the porous body and the fibrous layer, reεpectively, could be replaced by any other material with εimilar propertieε. The opening for the tube to the suction device could be located to the wollen layer if this was desirable, but it would then be necessary to arrange some kind of airtight duct inside the bag emerging close to the underside of the foam plastic body and there creating a negative air pressure. It would also be possible to locate said opening directly under the εeat and the rearεide of the backrest, respectively, or give it any other suitable location. Although a U-εhape and a line, respectively, are preferred fcr the patterns formed by the holes in the perforated member, other patterns would alεo be feaεable, although they would net be nearly aε effective.

Claims: Patent claims 1. A body-εupporting device forming the εeat (1) and/or the backreεt (15) of a chair and arranged to avoid sweating cauεed by the thermal inεulating capacity of the chair, c h a r a c t e r i z e d in that at least those sections (2) of the exterior surface of the device that form εupport sur¬ faces for parts of the body of a person εitting in the chair are made of a material that iε eaεily permeated by air, that at leaεt one opening (11) to the exterior is arranged in εaid device to communicate with the interior side of said air-per¬ meable sections (2), that the suction device (13) that iε capable of creating a negative air preεεure, εuch aε a εuction turbine, iε connectable to εaid opening and that the interior of the body-εupporting device iε so arranged that a εuction device, when connected and running, will cause air that is exterior to said support surfaces to be drawn through the air-permeable sections (2), via the interior of the body-εup¬ porting device and out of it through said opening (11), in order to remove heat radiated by the body of the perεon, in particular from the region between the relevant partε of the body and the air-permeable εectionε, and to cool the latter by meanε of the air-εtreams generated. 2. A device according to claim 1, c h a r a c t e r i z e d in that at least the exterior sufaceε of the body-εupporting device adjacent to εaid support εurfaceε are made of subεtan- tially airtight material, εo that virtually all air to be drawn to εaid opening (11) will paεε the εectionε forming εupport εurfaceε. 3. A device according to claim l or 2, c h a r a c t e r i ¬ z e d in that in its interior a suction-equalizing arrangement (6-10) is arranged to create a substantially even diεtribution cf the negative air pressure generated by the suction device (13), over the inner side of the air-permeable sections (2) forming εupport surfaces. 4. A device according to claim 3, c h a r a c t e r i z e d in that the suction-equalizing arrangement comprises a perforated member (6) of subεtantially airtight material, εo placed that the air drawn by the suction device (13) through the air-per¬ meable sections (2) must pasε through the holeε of the per¬ forated member (7) in order to reach εaid opening (11). 5. A device according to claim 4, c h a r a c t e r i z e d in that the holeε (7) of the perforated member are located close to the sections forming εupport surfaces, and that the holes (7) are εo arranged that they together form a pattern that εubstantially correεpondε to the shape of the projection onto the εeat (1) and/or backreεt (15) of thoεe partε of the body intended to bear thereupon, εo that in the caεe that the body-εupporting device form a seat a U-shaped pattern corres¬ ponding to the shape formed by the thighs and buttockε of a perεon, and in the caεe that it forms a backreεt, a line correεponding to a projection of the spinal column of the person onto the backreεt, is formed, whereby the air suction iε concentrated to but evenly distributed over those partε of εaic εectionε forming εupport εurfaceε intended to be covered by partε of the body of a perεon εitting in the chair. 6. A device according to claim 5, c h a r a c t e r i z e d in that the suction-equalizing arrangement compriεeε a porouε, air εtream diverging body (9) εuch aε a body of foamed plastic, so arranged that the air drawn through the holeε (7) of the perforated member must pasε through the porouε body (9) in order to reach said opening (11), that the porouε body (9; preεentε a firεt large εurface facing said holeε (7), and that the porouε body iε deεigned to creat÷ a negative preεεure (14) uniformly diεtributed over the last rentioned εurface εo as to apply εuch an effect equally to all c: the holeε (7,. 7. A device according to claim 6, c h a r a c t e r i z e d in that the firεt layer (8) of fibrouε material, preferably horsehair, iε located between the perforated member (6) and εaid firεt surface of the porouε member (9), so that bearing of the perforated member (6) againεt thiε surface and thereby sealing of the surface pores of the porous member iε avoided and the air drawn towards said opening must pasε through the fibrous material (8). 8. A device according to claim 7, c h a r a c t e r i z e d in that a εecond layer of fibrouε material iε located onto a εecond large εurface of the porouε body (9) turned in the oppoεite direction to the first εurface, and that the bag preεentε εaid opening (11) to which the εuction device (13) may be connected on the εame εide of the porous body (9) aε the εecond layer (10) of fibrouε material iε located, εo that thiε dispoεal and the tight bearing of the perforated member (6) againεt said arrangement prevent air from by-pasεing the porouε member (9) and lead to that air drawn from the exterior of the εectionε (2) forming support surfaceε to the opening (11) muεt paεε through the porouε body (9). 9. A device according to any of the preceeding claimε , c h a - r a c t e r i z e d in that the air-permeable material (2) iε wool. 10. A device according to claim 8, and forming both εeat (1) and backreεt (15) of a chair, c h a r a c t e r i z e d in that both εeat and backrest contain, interior to the air-per¬ meable sections (2), a perforated bag (6) containing an asεert- bl of fibrouε layerε (8, 10) and a foamed plaεtic body (9), each bag having an opening (11) for connection to a εuction device (13), and that the openings are located reεpectively at the lower part of the backreεt and at the rear of the εeat on the same side of the chair εo aε tz enable εimpie connection of both elaεtic bags (6) to the εame suction device (13 .

Inventors: TENNSTEDT CHRISTER, WYON DAVID, TENNSTEDT, CHRISTER, WYON, DAVID
Applicants: TENNSTEDT CHRISTER, WYON DAVID, TENNSTEDT, CHRISTER, WYON, DAVID
Application year: 1988
Main classification: A47C7
IPC codes: A47C7