Air cushion for shock absorption

Abstract

An air cushion for shock absorption according to the present invention, comprises a flexible and elastic foam material capable of restoring an air cell thereof to its original shape and size under a static pressure transformable by an impact force, a cover made of a soft non-porous material for closely enclosing the foam material in the inside thereof, a discharge valve formed in the cover for discharging an air in the inside of the air cell of the foam material to the atmosphere when the air cell is subject to the shock, and one or more intake valve formed in the cover separately from the discharge valve for intaking the atmosphere to the air cell when the air cell is restored to its original size and shape after impacted. When shocked or restored, the shock can be efficiently absorbed by selectively operating the discharge valve and intake valve and differing their volumes from each other. Thus, the articles, for example notebook computer, which are easily broken and damaged in performance, can be more perfectly protected by the air cushion.

What is claimed is:  
     
         1 . An air cushion for shock absorption comprising: 
 a flexible and elastic foam material capable of being restored to its original shape and size under static pressure after being subjected to an impact force;    a cover made of a soft non-porous material for closely enclosing and sealing the foam material;    at least one discharge valve formed in the cover for discharging air in the inside of the air cells of the foam material to the atmosphere when the air cushion is impacted; and    at least one intake valve formed in the cover for intaking the atmosphere to the air cells when the air cushion is restored to its original size and shape after being impacted.    
     
     
         2 . The air cushion of  claim 1 , wherein the cover is divided into an upper cover and a lower cover, each of which has flanges surrounding ends thereof, the discharge valve comprising a porous binder on the mating flanges, the atmosphere and the inside of the air cushion being in communication with each other through fine holes formed in the flanges and porous binder, which are formed when a suture is used to stitch the mating flanges, the fine holes being originally formed in the porous binder and the flanges.  
     
     
         3 . The air cushion of  claim 1 , wherein the discharge valve comprises a porous part in one portion of a lateral face of the cover.  
     
     
         4 . The air cushion of  claim 3 , wherein the porous part in the one portion of the lateral face of the cover includes a plurality of fine holes.  
     
     
         5 . The air cushion of  claim 3 , wherein the porous part is formed by cutting an area on the cover and attaching an additional porous material to the cut portion.  
     
     
         6 . The air cushion of  claim 1 , wherein the intake valve is constructed as a one-way valve, which is closed when the air cushion is subject to the shock but opened when the air cushion is restored.  
     
     
         7 . The air cushion of  claim 1 , wherein the intake valve comprises: 
 an opening formed in the bottom of the cover;    a valve plate attached to the internal bottom of the cover at one end thereof for vertical movement depending on a difference between the pressure inside the air cushion and the atmospheric pressure to open or close the opening; and    a recess formed in a bottom of the flexible foam material for receiving a valve plate, the recess providing appropriate space for the vertical open-and-close operation of the valve plate.    
     
     
         8 . The air cushion of  claim 7 , wherein the valve plate is made of a soft nonporous material, and wherein the valve plate is in close contact with the bottom of the cover due to a positive pressure generated inside the air cushion when the air cushion is compressed by a shock, thereby closing the opening, whereas a freely moving end of the valve plate is detached from the bottom of the cover due to a negative pressure generated inside the air cushion when the compressed air cushion is restored to its original size and shape, thereby causing the opening to allow the passage of air into the air cushion.  
     
     
         9 . The air cushion of  claim 7 , wherein the valve plate discharges internal air to the outside, through fine holes originally formed in the valve plate material itself, when the foam material is shocked by closing the opening due to the internal pressure generated, and the valve plate intakes the atmosphere to the air cushion through the opening when the flexible foam material is restored to its original size and shape by forcing open the opening when the freely moving end thereof is detached from the bottom of the lower cover due to the difference between a negative pressure generated inside and an atmosphere pressure.  
     
     
         10 . The air cushion of  claim 1 , wherein the cross sectional area of the intake valve for air communication is greater than the cross sectional area of the discharge valve for air communication.  
     
     
         11 . An air cushion for shock absorption comprising: 
 a flexible and elastic foam material capable of being restored to its original shape and size under a static pressure but being transformable by an impact force;    a cover made of a soft porous material for closely enclosing the foam material and functioning as an air discharge valve in communication with the inside of the air cushion and the atmosphere through fine holes formed in the porous material; and    one or more intake valves formed in the cover for intaking the atmosphere into the air cushion when the air cushion is restored to its original size and shape.    
     
     
         12 . The air cushion of  claim 11 , wherein the cross sectional area of the one or more intake valves for air communication is greater than the cross sectional area of the discharge valve.  
     
     
         13 . The air cushion of  claim 11 , wherein the air cushion includes a support member attached to an outer face of the lower cover for supporting the air cushion structure, the surface of the support member being made of a porous fiber for achieving smooth air communication through the opening of the intake valve on the lower cover.  
     
     
         14 . An air cushion for shock absorption comprising: 
 a flexible and elastic foam material capable of being restored to its original shape and size under a static pressure after being subjected to an impact force;    a cover divided into a lower cover in close contact with a bottom of the foam material, and an upper cover attached to the lower cover and closely covering portions other than the bottom of the foam material, at least one out of both covers made of a soft porous material for functioning as an air discharge valve in communication between the air cushion and the atmosphere through fine holes formed in the porous material; and    one or more intake valves formed in the lower cover for intaking the atmosphere into the air cushion when the air cushion is restored to its original size and shape after being subjected to the shock force,    wherein the intake valve comprises an opening formed in a bottom of the lower cover, a valve plate attached to an internal bottom of the cover at one end thereof and made of a soft material for opening and closing the opening by virtue of a vertical movement of the other freely moving end thereof, and a valve plate receiving recess formed in the bottom of the flexible foam material for providing appropriate room for the vertical open-and-close operation of the valve plate.    
     
     
         15 . The air cushion of  claim 14 , wherein the cross sectional area of the intake valve for air communication is greater than the cross sectional area of the discharge valve for air communication.  
     
     
         16 . The air cushion of  claim 14 , wherein the air cushion includes a support member attached to an outer face of the lower cover for supporting the air cushion structure, the surface of the support member being made of a porous fiber for achieving smooth air communication through the opening of the intake valve on the lower cover.  
     
     
         17 . An air cushion for shock absorption comprising: 
 a flexible and elastic foam material capable of being restored to its original shape and size under a static pressure but being transformable by an impact force;    a cover made of a soft non-porous material for completely sealing the foam material;    one or more intake valves formed in a lower cover for intaking the atmosphere into the air cushion when the air cushion is restored to its original size and shape after being subjected to an impact force;    wherein the cover is divided into the lower cover in close contact with a bottom of the foam material, and an upper cover fusion spliced on a top of the lower cover for closely enclosing portions other than the bottom of the foam material,    wherein the one or more intake valves comprise an opening formed in a bottom of the lower cover, and a valve plate attached to an internal bottom of the cover at one end thereof for opening and closing the opening by virtue of a vertical movement of a freely moving end thereof, and a valve plate receiving recess formed in the bottom of the flexible foam material for providing room appropriate for the vertical open-and-close operation of the valve plate,    wherein the valve plate is made of a porous material for discharging internal air to the outside, through fine holes originally formed in the valve plate material itself, when the foam material is shocked by closing the opening due to the internal pressure generated, and for intaking the atmosphere to the air cushion through the opening when the flexible foam material is restored to its original size and shape by opening the opening when the freely moving end thereof is detached from the bottom of the lower cover due to the difference between a negative pressure generated inside and an atmosphere pressure.    
     
     
         18 . The air cushion of  claim 17 , wherein the cross sectional area of the intake valve is greater than the cross sectional area of the discharge valve.  
     
     
         19 . The air cushion of  claim 17 , wherein the air cushion includes a support member attached to an outer face of the lower cover for supporting the air cushion structure, a surface of the support member made of a porous fiber for achieving smooth air communication through the opening of the intake valve on the lower cover.  
     
     
         20 . An air cushion for shock absorption comprising: 
 at least one shock-absorbing member, wherein the shock-absorbing member comprises a porous material having interstices for receiving air, wherein the porous material is capable of being deformed by an impact force, and wherein the material is capable of being restored to its original shape and size after being subjected to the impact force;    a cover for enclosing the shock-absorbing member, wherein the cover is made of a nonporous material;    at least one air discharge valve, formed in the cover, for discharging air from the shock-absorbing member into the atmosphere when the air cushion is subjected to an impact force;    at least one air intake valve, formed in the cover, for allowing air to pass from the atmosphere into the inside of the cover for filling the interstices of the shock-absorbing member, thereby restoring the shock-absorbing member to its original size and shape after the shock-absorbing member has been subjected to an impact force; and    wherein the at least one air intake valve is a one-way valve.