Patent Publication Number: US-2011070106-A1

Title: Air compressor structure

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to an air compressor structure, and more particularly to one having a main body, a fixing plate and a cap member which are secured together with fasteners to increase its strength so as to minimize vibration when the compressor is working and to prevent the compressor from leakage through an air passage and a chamber. 
     2. Description of Prior Art 
     A conventional air compressor comprises a cylinder, a cap member, and a valve located between the cylinder and the cap member to prevent air from backflow into the cylinder. US Patent Publication No. 20090104052 titled “Pump Improvements” discloses a cylinder, a valve connected with the cylinder, and an air tight cap coupled on the valve to prevent air from backflow into the cylinder. However, there are some shortcomings in this application. When a plunger in the cylinder is activated by a motor, it generates a vast vibration which causes a leakage of air from a gap between the air tight cap and the cylinder or a gap between an air tube and a lid. The valve prevents the air form leakage, but it cannot help the air tight cap and the cylinder to operate in a stable status. 
     SUMMARY OF THE INVENTION 
     The purpose of the present invention is to improve the leakage caused by vibration during operation. 
     According to the present invention, there is provided an air compressor structure, comprising: 
     a main body having a pair of cylinders, each of the cylinders comprising a plunger therein and a fixture on an outer wall thereof, the fixture having a pair of first threaded holes thereon; 
     a fixing plate comprising a handle and a pair of fixing portions extending from two sides of the handle, the pair of fixing portions corresponding to the pair of cylinders, each fixing portion comprising a fixing section and a recess thereon, the fixing section having a first air sealing ring thereon and being mounted in one of the cylinders of the main body, a second air sealing ring being provided in the recess, the fixing portion being formed with an air hole and a stop plate disposed on top of the air hole, the fixing portion further having a slot thereon and a pair of first lugs which has a pair of second threaded holes corresponding in position to the first threaded holes of the fixture; 
     a cap member comprising a tube having an air passage therein, a pair of third air sealing rings at two ends of the tube, and a pair of lids attached to the pair of third sealing rings at the two ends of the tube, the pair of lids corresponding to the pair of fixing portions of the fixing plate, the lids each covering one of the fixing portions and being against the second air sealing ring, the lids each comprising a chamber interconnecting with the air passage of the tube, a stud corresponding to the slot of the fixing portion, and a pair of second lugs corresponding to the pair of first lugs, the second lugs having a pair of third threaded holes corresponding to the first threaded holes and the second threaded holes; and 
     fasteners inserting through the third threaded holes, the second threaded holes, and the first threaded holes, respectively, to secure the cover member and the fixing plate to the main body. 
     It is the primary object of the present invention to provide an air compressor structure, which uses the fasteners inserting through the first, the second, and the third threaded holes, respectively, to secure the cap member, the fixing plate and the main body together so as to minimize vibration when the compressor is working and to prevent the compressor from leakage through the air passage and the chamber. 
     It is another object of the present invention to provide an air compressor structure, which uses the engagement of the slot of the fixture portion and the stud of the lid to enhance the strength of the cap member and the fixing plate as well as the stability of the cap member, the fixing plate and the main body. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of the present invention; 
         FIG. 2  is an exploded view of the present invention; 
         FIG. 3  is an exploded view of a cap member of the present invention; 
         FIG. 4  is a partially sectional view of the present invention; 
         FIG. 5  is a cross-sectional view showing fasteners inserting through first threaded holes, second threaded holes and third threaded holes to secure the cap member, a fixing plate and a main body of the present invention; and 
         FIG. 6  is a cross-sectional view of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to  FIG. 1  thru  5 , the air compressor structure of the present invention comprises a main body  1 , a fixing plate  2 , a cap member  3 , and fasteners  4 . 
     The main body  1  has a pair of cylinders  11 . Each cylinder  11  comprises a plunger  12  therein and a fixture  13  on an outer wall thereof. The fixture  13  has a pair of first threaded holes  14  thereon. 
     The fixing plate  2  comprises a handle  21  and a pair of fixing portions  22  extending from two sides of the handle  21 . The pair of fixing portions  22  corresponds to the pair of cylinders  11 . Each fixing portion  22  comprises a fixing section  221  and a recess  222  thereon. The fixing section  221  has a first air sealing ring  23  thereon and is mounted in the cylinder  11  of the main body  1 . A second air sealing ring  24  is provided in the recess  222 . The fixing portion  22  is formed with an air hole  25  and a stop plate  26  disposed on top of the air hole  25  as a cover to prevent air flow through the air hole  25  into the cylinder  11 . The fixing portion  22  further has a slot  27  thereon and a pair of first lugs  28  which has a pair of second threaded holes  281  corresponding in position to the first threaded holes  14  of the fixture  13 . 
     The cap member  3  comprises a tube  31  having an air passage  311  therein, a pair of third air sealing rings  32  at two ends of the tube  31 , and a pair of lids  33  attached to the pair of third sealing rings  32  at the two ends of the tube  31 . The pair of lids  33  corresponds to the pair of fixing portions  22  of the fixing plate  2 . Each lid  33  covers the fixing portion  22  and is against the second air sealing ring  24 . Each lid  33  comprises a chamber  331  interconnecting with the air passage  311  of the tube  31 , a stud  34  corresponding to the slot  27  of the fixing portion  22 , and a pair of second lugs  35  corresponding to the pair of first lugs  28 . The second lugs  35  have a pair of third threaded holes  351  corresponding to the first and second threaded holes  14 ,  281 . 
     The fasteners  4  are inserted through the third threaded holes  351 , the second threaded holes  281 , and the first threaded holes  14  to secure the cover member  3  and the fixing plate  2  to the main body  1 . 
     When the present invention is in use, as shown in  FIG. 6 , the plungers  12  are operated in the cylinder  11 . Between each cylinder  11  and each fixing portion  22  of the fixing plate  2 , the first air sealing ring  23  on the fixing section  221  is used to prevent the air from leakage through each cylinder  11 . Between each lid  33  of the cover member  3  and each fixing portion  22  of the fixing plate  2 , the second air sealing ring  24  in the recess  222  is used to prevent the air from leakage through the chamber  331 . Between the air passage  311  of the cover member  3  and each lid  33 , the third air sealing ring  32  is used to prevent the air from leakage through the air passage  311 . The operation of the plungers  12  in the cylinders  11  causes a vast vibration which may change the positions of the cylinders  11 , the fixing plate  2  and the cap member  3  and result in air leakage. With the engagement of the stud  34  of each lid  33  and the slot  27  of each fixing portion  22 , the strength of the cap member  3  and the fixing plate  2  is enhanced. When the plungers  12  are reciprocated in the cylinders  11 , the air in the cylinders  11  is compressed and expanded along with the movement of the plungers  12 , which generates different vibrations of the two cylinders  11 . The handle  21  is adapted to conduct the different vibrations of the cylinders  11  at respective ends so as to stabilize the two cylinders  11 . The fasteners  4  are inserted through the third threaded holes  351 , the second threaded holes  28  and the first threaded holes  14  to lock the second lugs  35 , the first lugs  28 , and the fixture  13  together, which increases the stability of the assembly and prevents the cylinders  11  of the main body  1 , the fixing plate  2  and the cap member  3  from moving their positions caused by the different vibrations of the cylinders  11 .