Patent Publication Number: US-2012042844-A1

Title: Handheld primer bulb structure

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to a device for transferring engine fuel, and more particularly to a handheld primer bulb structure. 
     2. Description of the Related Art 
     A handheld primer bulb is used to transfer engine fuel to an engine of a small-size engine-powered transportation tool such as a small-size boat. The primer bulb is a spherical or ellipsoidal body. Two ends of the primer bulb are respectively connected with two hoses. A user can manually compress and release the primer bulb to transfer the fuel to the engine. 
     Please refer to  FIGS. 1 and 2 . A conventional handheld primer bulb  91  is made of synthetic rubber or a mixture of synthetic rubber and polyvinyl chloride (PVC). Referring to  FIG. 2 , the shell/interface  911  of the primer bulb  91  is solely made of the aforesaid material so that the highly volatile fuel tends to permeate through the shell/interface  911  of the primer bulb  91  to the atmosphere to pollute the environment. 
     United State Coast Guard (USCG/SAE J1527) requires that the permeability of the fuel be not greater than 15 g/m 2 24 hrs. In this case, the conventional primer bulb  91  fails to meet the requirement of United State Coast Guard. 
     SUMMARY OF THE INVENTION 
     It is therefore a primary object of the present invention to provide a handheld primer bulb structure with low permeability. 
     It is a further object of the present invention to provide the above handheld primer bulb structure, which meets the requirement of environmental protection. 
     To achieve the above and other objects, the handheld primer bulb structure of the present invention includes an outer layer, an inner layer, an intermediate layer and a chamber. The outer layer is made of a thermoplastic elastic material and has the configuration of a spherical body. The inner layer is made of a fluoroplastic material (fluorocarbon polymer) and disposed on an inner face of the outer layer. The intermediate layer is disposed between the outer layer and the inner layer for affixing the inner layer and the outer layer to each other. The chamber is surrounded and defined by the outer layer and the inner layer and the intermediate layer and has two openings. 
     The present invention can be best understood through the following description and accompanying drawings, wherein: 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a conventional handheld primer bulb; 
         FIG. 2  is a sectional view taken along line A-A of  FIG. 1 ; 
         FIG. 3  is a perspective view of the handheld primer bulb structure of the present invention; and 
         FIG. 4  is a sectional view taken along line B-B of  FIG. 3 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Please refer to  FIGS. 3 and 4 . The handheld primer bulb structure  1  of the present invention at least includes an outer layer  12 , an inner layer  14 , an intermediate layer  16  and a chamber  18 . 
     The outer layer  12  is made of a thermoplastic elastic material with a mold by means of heating and molding. The thermoplastic elastic material can be rubber, polyvinyl chloride (PVC), polyurethane (PU), polyethylene (PE) or the like. The outer layer  12  can have the configuration of a spherical or ellipsoidal body. 
     The inner layer  14  is made of a fluoroplastic material (fluorocarbon polymer) with a mold by means of heating and molding. The inner layer  14  is disposed on an inner face of the outer layer  12  and has a configuration corresponding to that of the outer layer  12 . The fluoroplastic material (fluorocarbon polymer) can be polytetrafluoroethylene (PTFE), perfluoroalkoxyethylene (PFA), fluorinatedethyleneprogylene (FEP), polychlorotrifluoroethylene (PCTFE), ethylenetetrafluoroethylene (ETFE), ethylenechlorotrifluoroethylene (ECTFE), polyvinylidene difluoride (PVDF) or the like. 
     The intermediate layer  16  is disposed between the outer layer  12  and the inner layer  14  for affixing the inner layer  14  and the outer layer  12  to each other. The intermediate layer  16  can be an adhesive for adhering the inner layer  14  and the outer layer  12  to each other. Alternatively, the inner layer  14  can be affixed to the outer layer  12  in the following manners: 
     First, the inner layer  14  can be affixed to the outer layer  12  by means of a measure similar to fusion, that is, sintering. One face of the inner layer  14  (fluorocarbon polymer), which is proximal to the outer layer  12 , is heated to a high temperature. Then the inner layer  14  is compactly pressed against the inner face of the outer layer  12  and affixed thereto. 
     Second, in high vacuum condition under an electric field or plasma, the face of the inner layer  14  (fluorocarbon polymer), which is to be adhered to the outer layer  12 , is collided with ions. Accordingly, the fluorine atoms of the face are collided away and replaced with other atoms (such as oxygen). In this case, the face of the inner layer  14  is provided with strong adhesion. 
     The chamber  18  is surrounded and defined by the outer layer  12 , the inner layer  14 , and the intermediate layer  16  and has two openings  82 . 
     The inner layer  14  of the primer bulb structure  1  of the present invention is made of high-density fluoroplastic material (fluorocarbon polymer). When a user manually compresses the primer bulb to transfer the engine fuel, the permeability of the engine fuel is not greater than 15 g/m 2 24 hrs. Therefore, the primer bulb structure  1  of the present invention meets the requirement of United State Coast Guard. 
     The outer layer  12  of the primer bulb structure  1  of the present invention can have a thickness 15-20 times the thickness of the inner layer  14 . This makes the primer bulb structure  1  of the present invention have better elasticity to achieve better effect. 
     The above embodiments are only used to illustrate the present invention, not intended to limit the scope thereof. Many modifications of the above embodiments can be made without departing from the spirit of the present invention.