TECHNICALFIELD The present invention relates to an air cushion applicable to all products requiring cushions, and more particularly, to an air cushion capable of naturally supporting the human body along contours thereof, performing a multi-cushioning function of reducing a hard feel, and additionally giving different cushioning effects to respective parts of the human body.

BACKGROUND ART Cushions are required in a group of products including sofas, chairs, mattresses, seats and the like. Among them, certain products such as mattresses and sofas should be susceptible to cushioning sensitivity by nature. In particular, since mattresses should provide an optimum comfortable condition for a deep sleep by nature, spring mattresses or latex mattress satisfying such a condition are widely used. However, a spring mattress provides a superior supporting force, which is used to support the human body, but has a disadvantage in that it exhibits poor comfort. In addition, a latex mattress exhibits good comfort but has a disadvantage in that it provides a poor supporting force. To supplement these disadvantages of the mattresses, a hybrid type mattress in which the features of such spring and latex mattresses are combined is often used. However, there are problems in that the hybrid type mattress is very expensive and also too bulky to be easily moved. Therefore, an air mattress is recently popularized instead of these conventional mattresses. It is considered that a general air mattress has an inflated shape by injecting air into a single cell in the same manner as a balloon. Such a simple air mattress has many disadvantages in that it severely surges to deteriorate stability, such severe surging due to movement of a sleeping user may affect another sleeping user next thereto so that the air mattress cannot be applied to a large mattress for a double bed or a queen size bed, the simple air mattress gives only an extremely strong or weak cushioning force depending on the amount of filled air to deteriorate stability, and it cannot support the human body in balance. That is, the simple air mattress does not sufficiently meet basic requirements of a mattress. In particular, considering the traditional sleeping habit of Koreans familiar with the Korean under-floor heating system, a hard mattress is more preferred to a soft mattress. Thus, most Koreans generally tend to inject a great deal of air into a cell in order to make a mattress hard. Such a hard mattress decreases a cushioning force, so that the waist of a user who lies down on the bed comes off the surface of the air mattress. Thus, the mattress cannot support the waist as a whole, leading to lumbago in the user. Meanwhile, in case of using the air mattress in a soft state, the waist does not come off the surface of the mattress, but a so-called hammock phenomenon in which the hip is sunk too much occurs, which is also a cause of the occurrence of lumbago.

DISCLOSURE OF INVENTION

TECHNICAL PROBLEM Accordingly, the present invention is conceived to solve the problems in the prior art. An object of the invention is to provide an air cushion, which can naturally support the human body along contours thereof, perform a multi-cushioning function of reducing a hard feel, and give different cushioning effects to respective parts of the human body.

TECHNICAL SOLUTION According to the present invention for achieving the object, there are provided: (1) An air cushion, including an air injection tube with a valve at its one end, a flexible blocking tube contained in the air injection tube and having a valve at its one end, and a plurality of air cells each of which has one end connected to the air injection tube to communicate therewith, comprising: a housing including a plurality of pockets partitioned by elastic baffles so that the air cells can be individually inserted into the pockets. (2) An air cushion, comprising: first and second air injection tubes each of which has a valve at one end thereof; first and second flexible blocking tubes which are contained in the first and second air injection tubes, respectively, and each of which has a valve at one end thereof; a plurality of first and second air cells connected to the first and second air injection tubes to communicate therewith, respectively; and a housing having a plurality of pockets partitioned by elastic baffles so that the first and second air cells are individually inserted thereinto alternately in a lateral direction. (3) An air cushion, including an air injection tube with a valve at its one end, a flexible blocking tube contained in the air injection tube and having a valve at its one end, and a plurality of air cells each of which has one end connected to the air injection tube to communicate therewith, comprising: a housing with the respective cells inserted thereinto, wherein the housing is constructed by coupling a plurality of unit pockets, which are made of a fabric and take the shape of a rectangular case, to one another by means of coupling means selected from the group consisting of a zipper, a Velcro tape, a button and a hook. (4) An air cushion, comprising: first and second air injection tubes each of which has a valve at one end thereof; first and second flexible blocking tubes which are contained in the first and second air injection tubes, respectively, and each of which has a valve at one end thereof; a plurality of first and second air cells connected to the first and second air injection tubes to communicate therewith, respectively; and a housing with the first and second air cells inserted thereinto, wherein the housing is constructed by coupling a plurality of unit pockets, which are made of a fabric and taking the shape of a rectangular case, to one another by means of coupling means selected from the group consisting of a zipper, a Velcro tape, a button and a hook. (5) An air cushion, comprising: an air injection tube with a valve at its one end, a flexible blocking tube contained in the air injection tube and having a valve at its one end, and a plurality of air cells each of which has one end connected to the air injection tube to communicate therewith, wherein the surface of each of the air cells has a double-ply structure in which an outer sheet made of a fabric and an inner sheet made of a synthetic resin are overlapped together. (6) An air cushion, comprising: first and second air injection tubes each of which has a valve at one end thereof; first and second flexible blocking tubes which are contained in the first and second air injection tubes, respectively, and each of which has a valve at one end thereof; and a plurality of first and second air cells connected to the first and second air injection tubes to communicate therewith, respectively, wherein the surface of each of the first and second air cells has a double-ply structure in which an outer sheet made of a fabric and an inner sheet made of a synthetic resin are overlapped together. (7) An air cushion, including an air injection tube with a valve at its one end, a flexible blocking tube contained in the air injection tube and having a valve at its one end, and a plurality of air cells each of which has one end connected to the air injection tube to communicate therewith, wherein the air cushion is constructed to be connected to another air cushion in such a manner that a pair of air cushions are oppositely disposed in a line in a state where ring portions of the opposite air cushions are staggeredly arranged, and a cushioning member is inserted into the staggeredly arranged ring portions. (8) An air cushion, comprising: air cells arranged in parallel, the air cells being filled with a fluid; a plurality of cushioning members interposed between the respective air cells; and upper and lower cover sheets bonded to upper and lower surfaces of the air cells.

ADVANTAGEOUS EFFECTS According to the present invention, the human body can be naturally supported along contours thereof, a multi-cushioning function of reducing a hard feel can be performed, and the degree of cushioning can be adjusted to meet user's taste or body conditions through regulation of air pressure in each cell.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 shows an air cushion according to a first embodiment of the present invention. Fig. 2 is a cross sectional view showing a coupled state of the air cushion of Fig. 1. Fig. 3 is a sectional view taken along line I-I of Fig. 2. Fig. 4 is a view showing an installation state of a first cushioning member. Fig. 5 is an enlarged view showing both the installation state and a compressed state of the first cushioning member. Fig. 6 is a view showing an installation state of an air injection tube. Fig. 7 is a sectional view taken along line H-II of Fig. 6. Fig. 8 is a view showing an installation state of a second cushioning member. Fig. 9 is a view showing the process of forming a ring portion. Fig. 10 is a sectional view taken along line IH-III of Fig. 9. Fig. 11 is a view showing a state where air is injected into an air cell. Fig. 12 is a view showing a state where the air cell is blocked. Fig. 13 is a view showing a deformed state of the air cell upon application of an external force thereto. Fig. 14 shows an air cushion according to a second embodiment of the present invention. Fig. 15 is a cross sectional view showing a coupled state of the air cushion of Fig. 14. Fig. 16 shows an air cushion according to a third embodiment of the present invention. Fig. 17 shows an air cushion according to a fourth embodiment of the present invention. Fig. 18 shows an air cushion according to a fifth embodiment of the present invention. Fig. 19 is a view showing the process of manufacturing an air cell according to the present invention. Fig. 20 shows an air cushion according to a sixth embodiment of the present invention. Fig. 21 is a sectional view taken along line IV-IV of Fig. 20. Figs. 22 to 27 are views showing the other processes of manufacturing an air cell. Figs. 28 to 32 are views showing the process of coupling air cells to upper and lower cover sheets.

<Explanation of reference numerals for designating main components in the drawings> 3: Air cell 3c: Inner sheet 3d: Outer sheet 4, 5, 6: Cushioning member 7a, 7b: Upper and lower cover sheets 11 : Elastic baffle 10: Housing 12: Pocket 20: First cushioning member 21 : Second cushioning member

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the accompanying drawings, Fig. 1 shows an air cushion according to a first embodiment of the present invention, Fig. 2 is a cross sectional view showing a coupled state of the air cushion of Fig. 1, Fig. 3 is a sectional view taken along line I-I of Fig. 2, Fig. 4 is a view showing an installation state of a first cushioning member, Fig. 5 is an enlarged view showing both the installation state and a compressed state of the fist cushioning member, Fig. 6 is a view showing an installation state of an air injection tube, Fig. 7 is a sectional view taken along line II-II of Fig. 6, Fig. 8 is a view showing an installation state of a second cushioning member, Fig. 9 is a view showing the process of forming a ring portion, Fig. 10 is a sectional view taken along line III-III of Fig. 9, Fig. 11 is a view showing a state where air is injected into an air cell, Fig. 12 is a view showing a state where the air cell is blocked, Fig. 13 is a view showing a deformed state of the air cell upon application of an external force thereto, Fig. 14 shows an air cushion according to a second embodiment of the present invention, Fig. 15 is a cross sectional view showing a coupled state of the air cushion of Fig. 14, Fig. 16 shows an air cushion according to a third embodiment of the present invention, Fig. 17 shows an air cushion according to a fourth embodiment of the present invention, Fig. 18 shows an air cushion according to a fifth embodiment of the present invention, Fig. 19 is a view showing the process of manufacturing an air cell according to the present invention, Fig. 20 shows an air cushion according to a sixth embodiment of the present invention, Fig. 21 is a sectional view taken along line IV-IV of Fig. 20, Figs. 22 to 27 are views showing the other processes of manufacturing an air cell, and Figs. 28 to 32 are views showing the process of coupling air cells to upper and lower cover sheets.

Air Cushion of First Embodiment Refer to Figs. 1 to 13. An air cushion includes an air injection tube 1 with a valve v at its one end, a flexible blocking tube 2 that is contained in the air injection tube and has a valve v at its one end, and a plurality of air cells 3 each of which has one end connected to the air injection tube to communicate therewith. The air cushion of the present invention further comprises a housing 10 including a plurality of pockets 12 partitioned by elastic baffles 11 so that the air cells 3 can be individually inserted into the pockets. The elastic baffle 11 serves to partition an inner space of the housing 10 and to give an additional multi-cushioning function in addition to cushioning forces of the air cells by exhibiting an elastic action according to deformation of the air cells 3 caused by an external force. These functions will be described in detail later. At this time, each of the elastic baffles 11 may be formed in a single ply or multiple (or many) plies. In case of multiple plies, it is possible to create another cushioning force in addition to the elastic baffles by inserting first cushioning members 20 such as airbags or sponges between the plies of the baffles, as shown in Fig. 4. In addition, it is possible to adjust a cushioning force by changing the cushioning strength (hardness), shape or configuration of each of the first cushioning members 20 during manufacturing processes thereof. Moreover, all cushioning members that will be described later, including the first cushioning members, may employ sponges or airbags well known in the art but are not limited thereto. Various kinds of cushioning materials may be applied thereto. Particularly, in case of an airbag 20a, as shown in Fig. 4, an inlet/outlet hole 20a' is formed at the airbag, a fluid injection tube 20b is installed to the inlet/outlet hole, a fluid control valve 20c is installed at a connection between the fluid injection tube and the air bag to control the amount of fluid injected into the airbag, a pump 2Od is installed at one side of the fluid injection tube 20b to inject and discharge a fluid, and a controller 2Oe for controlling the pump is installed. Thus, since the amount of fluid injected or discharged into/from the airbag 20a can be controlled by means of the controller, a cushioning force can be ultimately controlled. Such a configuration is commonly applied to all the following embodiments. Meanwhile, assuming that the air cells 3 are applied to a mattress and arranged such that longitudinal directions thereof intersect the height of a user, the air cells are grouped into several regions according to parts of the human body supported by the air cells, and the widths b of the air cells may be changed by region. At this time, as for important matters upon determination of the widths of the air cells, if air cells with a small width are densely arranged, the air cells can be deformed to finely conform to a concave part (e.g., the waist) or a convex part (e.g., the hip) of the human body. Thus, the air cells positioned in such a region should have small widths b (see regions A and B of Fig. 3), whereas other parts that do not require fine deformation may have relatively large widths. Since such changes in the widths of the air cells 3 should be related to the widths of the pockets of the housing 10, the widths b ' of the pockets should be determined on the same basis as the widths of the air cells. At this time, it should be noted that the heights h and h ' of the air cells 3 and the pockets 12 should be constant regardless of regions. This is because inconstant heights cause the surface of the air cushion itself to undulate, thereby increasing uneasiness. Besides, the air injection tube 1 and each of the air cells 3 may be made integrally with or separately from each other. In case of the separated type, they are detachably connected to each other by means of a connector c. This structure is useful when the air cell is replaced. Further, a lower portion of one end of the air cell 3 is provided with an embedment groove 3a in which the air injection tube 1 is embedded. Thus, the air injection tube can be effectively installed without protruding outwardly. In addition, the other end of the air cell 3 is folded upwardly or outwardly and bonded to itself to form a ring portion 3b. A second cushioning member 21 such as an airbag or a sponge is inserted into the ring portion. The second cushioning member creates a multi-cushioning function in the same manner as the elastic baffle 11 and the first cushioning member 20. Reference numeral 30 that has not yet been described indicates an edge finish material for finishing the edge of the air cushion. Here, since the edge finish material is to confine the outline of the air cell, it should have some degree of rigidity but not be too stiff. In addition, to ensure binding of the edge finish material to the housing 10, the housing is provided with binding bands 10a that in turn wrap and are coupled to the periphery of the edge finish material. At this time, an elastic or inelastic material can be used for the binding bands 10a. Alternatively, the binding bands 10a may be formed at the air cells 3 as shown in Fig. 7. The air cushion of the first embodiment constructed as above is used as follows. The respective air cells 3 are individually inserted into the pockets 12 of the housing 10. Then, air is injected through the valve v of the air injection tube I9 the respective air cells 3 communicating with the air injection tube are filled with air at once. When a suitable amount of air is filled in the respective air cells, the valve of the air injection tube is closed and air is then injected into the blocking tube 2 through the valve v of the blocking tube 2. At this time, if air is sufficiently filled in the blocking tube such that air pressure therein is greater than that in the air injection tube, inlets of the respective air cells are blocked by means of the inflated blocking tube 2. Thus, the air cells do not communicate with one another. When the air filling operation is completed, the air cushion can be used as a mattress. Thus, if a user lies down on the air cushion, the air cells 3 directly subjected to the user's weight are compressed in a vertical direction. Each of the compressed air cells 3 exhibits compensation lateral expansion P as much as the compressed volume. However, since the air cell is restrained by restriction pressure -P of other adjacent air cells, it is not extremely collapsed at any region. Thus, there is no phenomenon in which the hips droop. In addition, since air cells that support the hips and the waist have small widths b and are arranged densely, they are deformed to conform to the contours of the hips and the waist so that they can support these parts closely without any gap therebetween, thereby relieving lumbago while a user sleeps thereon. At this time, since deformation of the air cells 3 is limited between adjacent air cells 3 due to the restriction pressure -P, some users may feel that the degree of cushioning thereof is somewhat hard. However, since cushioning forces are provided in two or multiple stages by means of the elastic baffles 11, the first cushioning members 20, the second cushioning member 21 and the binding bands 10a, which are positioned between the air cells 3, such a hard feel can be eliminated.

Air Cushion of Second Embodiment Refer to Figs. 14 and 15. An air cushion of the second embodiment is substantially similar to the air cushion of the first embodiment, except that a pair of assemblies each of which comprises an air injection tube, a blocking tube and air cells are inserted into the housing 10 at opposite sides of the housing such that air cells 3-1 and 3-2 of the assemblies are alternately arranged, respectively. Here, one assembly comprises a first air injection tube 1-1, a first blocking tube 2-1 and first air cells 3-1, and the other assembly comprises a second air injection tube 1- 2, a second blocking tube 2-2 and second air cells 3-2.

Air Cushion of Third Embodiment Refer to Fig. 16. Although an air cushion of the third embodiment is identical to the aforementioned embodiments in that it comprises an air injection tube, a blocking tube and air cells (not shown), it is distinguishable therefrom in that a housing 10 is not an integral type but an assembly type. In other words, the housing 10 is constructed by consecutively connecting individual unit pockets 10-1, which are made of a fabric and take the shape of a rectangular case, to one another using coupling means such as zippers 10-2, sewing, Velcro tapes, buttons and hooks. Here, since the coupling means exhibit poor appearance if they are exposed to the outside, it is preferred that shields 10-3 for concealing the coupling means be provided at portions of the unit pockets 10-1 where the coupling means are installed. More preferably, cushioning members 10-4 are disposed in spaces s between the unit pockets 10-1.

Air Cushion of Fourth Embodiment Refer to Fig. 17. An air cushion of the fourth embodiment is identical to the aforementioned embodiments in that it comprises an air injection tube and a blocking tube (not shown). However, it is distinguishable therefrom in that a housing is integrated into air cells. That is, contrary to the first to third embodiments, there is no housing in this embodiment, and the surface of each of the air cells 3 has a double-ply structure composed of an inner sheet 3c and an outer sheet 3d. The inner sheet 3c is made of a synthetic resin and the outer sheet 3d is made of a textile, and the inner and outer sheets are then thermally welded. In addition, shields 3e are formed, as coupling means, at respective edges of the air cells 3 in the same manner as the third embodiment to connect the air cells to one another. More preferably, cushioning members 4 are disposed in spaces s defined by the shields between the air cells 3.

Air Cushion of Fifth Embodiment Refer to Fig. 18. An air cushion of the fifth embodiment is constructed such that two or more air cushions can be connected to each other. This air cushion is characterized in that an air cushion A and an air cushion B having the same configuration as the first embodiment are oppositely disposed, ring portions 3b of the air cushion A and ring portions 3b' of the air cushion B are arranged staggeredly, and a cushioning member 5 is sequentially inserted into the staggeredly arranged ring portions 3b and 3b'. This embodiment is useful for implementing a wide air cushion. As for a mattress, for example, this embodiment enables enlargement of a single size mattress into a double, queen or king size mattress. Meanwhile, blow molding is used for manufacturing the air cells employed in the first to fifth embodiments. In the blow molding, as shown in Fig. 19, a blow B surrounded by a raw material for the air cells is interposed between two left and right molds Ml and M2, and air is then injected into the blow so that the raw material comes into close contact with inner surfaces of the two molds by means of discharge forces of the air, thereby forming desired air cells.

Air Cushion of Sixth Embodiment Refer to Figs. 20, 21, 22 to 27, and 28 to 32. The sixth embodiment proposes a kind of air cushion that can be mass-produced. Thus, the structure of this air cushion is concise and simple. As for the specific structure, the air cushion comprises a plurality of air cells 3 that are a completely closed type or an unclosed type with inlets, a plurality of cushioning members 6 interposed between respective adjacent air cells, and upper and lower cover sheets 7a and 7b bonded to upper and lower surfaces of the air cells. Reference numeral 8 indicates an outer cover. Each of the air cells 3 is constructed such that a rectangular raw sheet 3 f made of vinyl or a similar material is folded in half onto itself as shown in Fig. 22, and the overlapped edges are thermally welded and sealed as shown in Figs. 23 and 24. At this time, a portion of the edges to be sealed is not welded to be used as an inlet/outlet for a fluid. As for the formation of the inlet/outlet, a welding prevention tape 3g is attached or a tube is installed to a portion of the edges of the raw sheet before the raw sheet 3f is folded in half and the edges are welded. Then, remaining portions except the portion where the welding prevention tape is attached are thermally welded. When the welding prevention tape is removed, the inlet/outlet is formed at the portion where the welding prevention tape was positioned. Thereafter, as shown in Fig. 24, both surfaces of the thermally welded raw sheet 3f are pulled in directions designated by arrows shown in the figure so as to make a substantially hexahedral shape, as shown in Fig. 25, in such a manner that a welded portion 3h of each of three sides is positioned at the center of a corresponding surface of the hexahedron. In this state, respective corners are thermally welded in a direction intersecting a long side 3f (a direction designated by dotted lines in Fig. 25), thereby forming upper and lower triangular flaps 3i and 3j as shown in Fig. 26. When both the welding process and the flap forming process are completed, a fluid is injected into the air cells 3. The air cells expand to make a perfect three- dimensional hexahedron. Upon combination of the upper and lower cover sheets 7a and 7b with the hexahedral air cells 3, each of the air cells that has been expanded through injection of the fluid into the air cell 3 as shown in Fig. 27 is automatically transferred using a conveying machine such as a conveyor 9. At this time, the air cells are transferred in a state where the cushioning members 6 are interposed between adjacent air cells as shown in Fig. 28. Next, an adhesive b is applied on the upper surfaces of the respective air cells 3 being transferred, as shown in Fig. 29. The upper cover sheet 7a wound around a roll or the like is then consecutively attached to portions where the adhesive is applied, as shown in Fig. 30. In addition, as shown in Figs. 31 and 32, while the air cells 3 are transferred in an inverted state, the lower cover sheet 7b is attached in the same way as the attachment of the upper cover sheet.

INDUSTRIAL APPLICABILITY According to the present invention described above, the human body can be naturally supported along contours thereof, a multi-cushioning function of reducing a hard feel can be performed, and the degree of cushioning can be adjusted to meet user's taste or body conditions through regulation of air pressure in each cell.