Double shell structure for air pumps

Abstract

A double shell structure for air pumps has an outer shell and an inner shell housed in the outer shell for installing an air pump body. The double shell structure can effectively reduce noise leakage resulting from air pump operation.

I claim:  
     
         1 . A double shell structure for air pumps comprising an outer shell and an inner shell housed in the outer shell, the outer shell and the inner shell being interposed by a hollow space therebetween, the inner shell having a hollow housing chamber for installing an air pump body such that noise resulting from operation of the air pump body is reduced from leaking through the inner shell and the outer shell.  
     
     
         2 . The double shell structure for air pumps of  claim 1 , wherein the outer shell includes an outer upper lid and an outer base.  
     
     
         3 . The double shell structure for air pumps of  claim 1 , wherein the inner shell includes an inner upper lid and an inner base.  
     
     
         4 . The double shell structure for air pumps of  claim 3 , wherein the inner base has a lateral side which has at least one notch forming thereon.  
     
     
         5 . The double shell structure for air pumps of  claim 3 , wherein the inner upper lid has a downward recess which has a lid peripheral rim slightly larger than the outer peripheral rim of the inner base.  
     
     
         6 . The double shell structure for air pumps of  claim 5 , wherein the inner base has a top rim in contact with a soft pad, and the inner upper lid being covered on the soft pad to achieve a tightly sealing.  
     
     
         7 . The double shell structure for air pumps of  claim 6 , wherein the inner upper lid has an opening to allow an air inlet duct to run through.  
     
     
         8 . The double shell structure for air pumps of  claim 7 , wherein the soft pad and the inner upper lid are interposed by a thin sheet which has an opening to couple with a lower section of the air inlet duct.  
     
     
         9 . A double shell structure for air pumps comprising an outer shell and an inner shell housed in the outer shell, the outer shell and the inner shell being interposed by a hollow space therebetween, the inner shell having a hollow housing chamber for installing an air pump body, the outer shell having an outer upper lid which has an inner side forming a downward rim surrounding a recess for housing a soft pad to allow the outer upper lid to cover the top rim of the inner shell to increase tightly fastening effect.  
     
     
         10 . The double shell structure for air pumps of  claim 9 , wherein the inner shell has at least one notch to allow an air discharge duct to run through.