SUSPENDED CONSTRUCTION AND PREPARING METHOD THEREOF

Abstract: The interior suspension/support structure for inflatable items such as mattresses, pillows, rubber boats, lifejackets, etc., is mfd. by the attaching a pair of synthetic material sheets to the inner surfaces of the sheets of the inflatable body of the same double-layer construction, in such a way as to form suspended loops. These loops are then joined together by stitching and serve to prevent unwanted expansion of the inflatable body when inflated.

Description: TECHICAL FIELD This invention relates to a core structure for holding down an inflation of mattress, pillow case, rubber boat, life preserver and the like according to the precharacterising portion of claim 1. Such a core structure, is for instance known from the GB-A-774,719. BACKGROUND TECHNIQUE In the core structure of air mattress and the like, an inflation is held down generally by an I-beam system (FIG.3), X-beam system (FIG.4) and deformed X-beam system (FIG.5). In case of producing a boat, mattress, life preserver and the like by filling air in its inside with artificial leather like cloth sheets produced by pasting the cloth sheet made of Nylon, cloth and the like and the sheet made of vinyl, urethane, rubber and the like together, in order to secure an air cushioned portion in a proper thickness by holding down its inflation, the upper and lower artificial leather like cloth sheets 3 were directly fused (FIGS.4 and 5), ore core elements or members 4 were used which were produced by pasting both end portions of the core members 4 to the upper and lower artificial leather like cloth sheets 3 by means of an adhesive (FIG.3) whereby a core structure was produced. However, in the mattress and the like of the core structure of the conventional systems, when it was used for many years during which an anticipated load F was applied, the fused portion or the pasted together portion 10 was cut causing a leakage of air filled therein, and particularly, in case of using the core of the I-beam system, the pasted together portion (bonded surface) of the artificial leather like cloth sheet and the core member was peeled and lost the capability of holding down the inflation in some cases. Let us explain this phenomenon by referring to FIG.3, in which is shown that in case of the mattress of the I-beam structure, if the load F was applied to the upper portion of the mattress, a force F′ worked towards the outside around the periphery of an air chamber 8. Also, in case that the load F was higher than the anticipated value, the force F′ was accordingly increased on the periphery of the air chamber 8. As a result, the bonded surface 10 of the core member 4 was peeled from the artificial leather like cloth sheet or the cut started from the pasted together portion. Also, in case of the mattress of the X-beam structure, similar to the I-beam system , if the load f was applied in the direction of the upper part, there was the effect that the force F′ worked towards the outside around the periphery of the air chamber so that the fused surface portion 10 was broken and cause of a leakage of air from the air chamber 8. The deformed X-beam structure had the similar drawback. However, in the case of the air mattress, air pillow case and the like, the load F was not too big and also, the pneumatic pressure F′ of the air chamber 8 was not required to be a high pressure so that the holding down of the inflation of an air cushioned portion could be materialized by the core structure of the conventional system, but the product required to have a high pneumatic pressure of the air chamber with extremely high load F was not suitable, for example, to be used as the core member in a buoyance adjusting apparatus for scuba diving, life preserver and the like. This invention has been made in view of the foregoing points, and its object is to provide a core structure for air filled product capable of withstanding a large load and internal pressure. DISCLOSURE OF THE INVENTION The core according to this invention has a structure, as shown in a cross section of FIG.1, in which in the middle portions of the upper side and lower side artificial leather like cloth sheets 3 formed by pasting the sheets 2 made of the urethane, vinyl and the like and the insides of the cloth sheets 1 made of Nylon, cloth and the like together, a pair of core elements or member 4 of a double layer structure identical with the leather cloth sheets 3 is disposed, and both end portion 5 of the core elements 4 are fused to the upper side leather cloth sheet 3 and the lower side leather cloth sheet 3, and the center portions 6 of the core members 4 are sewn together with the yarn 7 to couple a pair of core members 4. Two pieces of core members 4 are sewn and coupled with the yarn at the location of the middle portions 6 so that even when the larger pneumatic pressure F′ is applied in the periphery of an air chamber 8, they do not separate from their coupled portions. Also, since the artificial leather like cloth sheet 3 and the end portion 5 of the core member 4 are fused in a face-to-face manner, the frictional contact is generated on the fused surfaces of the artificial leather like cloth sheet 3 and the core element or member 4 by the tensile forces A and B in the opposite directions if the larger pneumatic pressure F′ is applied into the air chamber. For this reason, even if a considerable pneumatic pressure is applied to the artificial leather like cloth sheet 3 and the core member 4, they do not separate from their fused portions. Since the core structure according to this invention is constituted in such a manner that the force of the bonded portion of the core member with the leather cloth sheet is held down by the surface, the strength of the bonding force is increased by several ten folds as compared to the core structure of the conventional products. In case of the high frequency fusing of the upper side and louver side leather cloth sheets of the air filled product, the fusing coupling of a pair of core members can be carried out simultaneously in one process. When the length of the yarn of the coupled portions of a pair of core members or the length of the core members, is adjusted the length of the fused and coupled portions of the core members and the length of the yarn of the coupled portions of the core members are also respectively properly adjusted, whereby an inflation of the air filled product can be controllably changed. Since the strength of the bonding force is increased by several ten folds as compared to the conventional products using heretofore the urethane sheet layer in the buoyance adjusting apparatus, it can be replaced now by a low cost vinyl sheet layer. Furthermore, a remarkable feature is that there is no danger that air leaks outside of the air chamber in case that the yarn sewn coupled portion is broken by some chance so that it is particularly suitable for life preservers and the like. BRIEF DESCRIPTION OF THE DRAWINGS FIG.1 and FIG.2 are cross sections of a core element or member according to this invention, FIGS.3 through 5 show the core structure of a conventional system, FIG.3a being its perspective view, FIG.3b being its lateral cross section, FIG.3c being a partially enlarged view of FIG.3b, FIG.4a being its perspective view, FIG.4b being its lateral cross section, FIG.4c being a partially enlarged view of FIG.4b, FIG.5a being its perspective view, and FIG.5b being its lateral cross section. MOST PREFERRED EMBODIMENTS OF THE INVENTION The core structure and the method of its manufacture according to this invention will be described in the following on the basis of the embodiments illustrated in FIGS.1 and 2. FIG.1 is a cross section of a core structure according to this invention used in a buoyance adjusting apparatus for use in scuba diving, and shows a condition before air is filled, and FIG.2 is a cross section similar to FIG.1 and shows a condition when air is filled. In the scuba diving, a buoyance adjusting apparatus is an important device for easy work several ten meters below the sea level. This buoyance adjusting apparatus is generally constituted in such a manner that the inside of the artificial leather like cloth sheet 3 of a coupled layer structure consisting of the outside layer 1 being a Nylon cloth sheet and the inside layer 2 being a thin sheet made of urethane. This buoyance adjusting apparatus is provided with a core structure functioning to avoid or keep small an inflation of an air chamber 8 to enable an easy movement in the water. The conventional core structure was made by the deformed X-beam system as shown in FIG.5, and an explanation is provided by referring to the part of this invention shown in FIG.1, in which the upper and lower side artificial leather like cloth sheets 3 were fused directly by high frequency by means of respective urethane sheet layers 2. The buoyance adjusting apparatus fed air into the air chamber 8 for the adjustment of buoyance as the diver dived deeper below the water level. For this reason, in the deep diving condition, the larger pneumatic pressure F′ worked towards the outside of the air chamber 8 so that in the case of the conventional core structure, the fused portion of the urethane sheet layer 2 was peeled or was broken in some cases. As the core according to this invention, the structure is provided as the core member in which a pair of artificial leather like cloth sheets 4 made of double layers, (a urethane sheet layer 2′ and a Nylon cloth sheet layer 1′) of identical structure as compared to the leather cloth sheet 3 is provided inside of the air chamber 8. In the case, a pair of core members 4 is sewn by a sewing machine and coupled with a yarn 7 at their middle portions 6, and both end portions 5 of the core members 4 are fused and coupled with the urethane sheet layer 2′ of the core element or member 4 and the urethane sheet layer 2 of the leather cloth sheet 3. As the filling amount of air in the air chamber 8 is increased, as FIG.2 shows, the pneumatic pressure F′ works strongly towards the outside against the upper side and lower side leather cloth sheets 3 and a pair of core members 4 forming the periphery of the air chamber 8. However, the core structure of this invention is constituted in such a manner that a pair of core members 4 is sewn and coupled with a yarn 7, the coupled portions are not easily broken even if the strong pneumatic pressure F′ is applied to the coupled portions of a pair of core members 4. Also, in this case, the tensile forces A and B of opposite directions work on the fused surfaces of the artificial leather like cloth sheet 3 and the core member 4 to effect the peeling of the fused portions but there is an advantageous point that the surface fusing of the leather cloth sheet 3 and the core member 4 are not easily subjected to the peeling apart by a shift in the lateral direction mentioned above. Accordingly, when the core structure according to this invention is uved, even if a strong pneumatic pressure F′ is applied to the inside of the air chamber 8, the core member 4 hardly breaks. The core structure according to this invention can be manufactured by sewing and coupling a pair of core members 4 made of double layers, a Nylon cloth sheet layer 1′ and a urethane sheet layer 2 with a yarn 7 at the center portions 6 by setting the respective Nylon sheet layers 1′ inside in the first place, disposing a pair of coupled core members at a desired portion of an air chamber where the core members are located, and applying a pressure with high frequency to the upper side leather cloth sheet 3 in the direction of the upper part, and fusing both end portins 5 of the core members 4 to the upper side and lower side leather cloth sheets 3. The core structure according to this invention can be applied to the air filled product made of a single layer film sheet of rubber or synthetic resin and the like. In this case, the core members according to this invention can be made of a single layer film sheet of indentical material or an artificial leather like cloth sheet prepared by pasting the the single layer film sheet and cloth sheet layer together. Also, a pair of core members can be coupled by providing rivet holes on the coupled portions and riveting instead of the coupling with yarn sewing. INDUSTRIAL UTILIZATION By the way, the core structure according to this invention is particularly suitable for holding down or keeping small the inflation by particularly strong pneumatic pressure. For example, bouyance adjusting apparatus for rubber boat, scuba diving, and life preserver and the like.

Claims: 1. A core structure for holding down or keeping small the inflation of an air filled product made of soft plastics or rubber such as a mattress, the core structure comprising a pair of core members (4) arranged in an air chamber (8) which is formed by an upper and lower artificial leatherlike cloth sheet (3), whereby the core members (4) are fixed at their both end portions (5) to the upper and lower side sheets (3) while their middle portions (6) are sewn together with a yarn (7) for coupling the upper and lower sheets (3), characterised in that the sheets (3) are formed by pasting a first layer (2) made of urethane, vinyl or the like and a second layer (1) made of nylon, cloth or the like together, that the core members (4) are made of a double layer structure (1′,2′) identical to the structure of the sheets (3), that layers (1,1′,2,2′) of the same kind oppose each other in a face to face manner and that the core members (4) are fused at their both end portions (5) to the upper and lower side sheets (3) respectively. 2. A method of manufacturing a core structure for holding down the inflation of a product filled with air and made of soft plastics or rubber such as a mattress or the like, the method comprising coupling a pair of core members (4) each having a double layer structure formed by a first, cloth sheet layer (1′) and a second sheet layer (2′) made of urethane, vinyl or the like, the coupling being achieves by sewing with a yarn (7) the middle portions (6) of the first and second layers (1′2′) together with the first layers (1′) orientated inwards, disposing a pair of core members (4) in the middle portions of an upper side artificial leatherlike cloth sheet (3) and a lower side artificial leatherlike cloth sheet (3) prepared by pasting the insides of the cloth sheets (1) and a sheet (2) made of urethane, vinyl or the like together, applying a pressure with high frequency to the upper side artificial leatherlike cloth sheet (3) in the direction of the upper part, and fusing both end portions (5) of the core members (4) with the upper side and lower side artificial leatherlike cloth sheet (3).

Inventors: MIWA, FUKUICHI K. K. SANKO VINYL KOGYOSHO
Applicants: KABUSHIKI KAISHA SANKO VINYL KOGYOSHO
Application year: 1987
Main classification: A47C27
IPC codes: B63C9, A47G9, B63C7, B63C11, A47C27