Abstract:
A sealing cover includes a cover coupling with a seal ring which has two blades to form a double sealing effect. Thus a container can be sealed by the cover more securely and the opening of the container can be maintained intact. The cover also has a coupling opening and a plurality of air vents. The coupling opening is coupled with an air permeable parasol valve which can release air to facilitate capping of the cover on the opening of the container. Through an air suction means the container can be vacuumed.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This is a National Phase Application in the United States of International Patent Application No. PCT/CN2007/001937 filed on Jun. 20, 2007 in China. The entire disclosures of the above patent applications are hereby incorporated by reference. 
     FIELD OF THE INVENTION 
     The present invention relates to a sealing cover and particularly to a sealing cover that is simply structured and adaptable to be used on containers formed in various shapes and made from different materials and is vacuum-enabled. 
     BACKGROUND OF THE INVENTION 
     A conventional sealing cover adopted for use on containers of varying openings, such as an example of a container  10  shown in  FIG. 1  that has a round opening, mainly includes a cover  20  to cap a top rim  11  at the opening of the container  10 . The cover  20  has an annular groove  23  at a location in contact with the top rim  11 . A sealing pad  24  is provided in the groove  23 . When the top rim  11  is wedged in the groove  23  it forms a close contact with the sealing pad  24 . 
     The container  10  also has a plurality of jutting anchor portions  12  on an outer side close to the top rim  11 . The cover  20  has the perimeter coupled with latch ledges  21  which can be rotated relative to the cover  20 . Each of the latch ledges  21  has at least one aperture  22  corresponding to one anchor portion  12 . When the cover  20  is mounted onto the opening of the container  10 , the latch ledge  21  may be depressed towards the anchor portion  12  to allow the aperture  22  to be passed through by the anchor portion  12  to form a latched condition. Thus the cover  20  can tightly cap the opening of the container  10 . By tightly compressing the sealing pad  24  in the groove  23  through the top rim  11  the internal space of the container  10  is isolated from the exterior to form a sealed condition. 
     However, after repetitive latching and rotating when in use for a period of time, the latch ledges  21  are prone to break or fracture at the joined locations. While increasing the thickness at the joined locations can reduce the risk of breaking or fracturing, to latch and disengage the latch ledges  21  when in use require a greater effort. It also is not operable single-handed. Moreover, the design of the anchor portions  12  makes the opening of the container  10  difficult to maintain a desired integrity. For instance, when the opening is circular, the apertures  22  of the latch ledges  21  have to be aligned accurately with the anchor portions  12  to form a tight coupling. It is not convenient in practice. 
     To solve the aforesaid problem, another type of cover  40  has been developed as shown in  FIG. 2 . A container  30  with a round opening also is used as an example to mate the cover  40 . The container  30  has a smooth top rim  31  at the opening location. The cover  40  is located above the top rim  31 . The cover  40  has an annular jutting portion  43  at a lower side and a lower surface around the annular jutting portion  43  to form a top coupling portion  41 . The top coupling portion  41  has one spot extended outwards to form a moving flange  42 . The annular jutting portion  43  has an outer diameter slightly smaller than the inner diameter of the opening of the container  30  and an annular groove  44  surrounding an outer wall thereof. A blade type sealing ring  45  is provided to be wedged in the groove  44  with a portion exposed outside. The sealing ring  45  has an air vent  46  in the center on a selected location. 
     When the cover  40  is caped on the top rim  31  of the container  30 , the annular jutting portion  43  is squeezed in an inner side of the opening of the container  30 . The air in the container  30  is discharged through the air vent  46  to allow the annular jutting portion  43  and the sealing ring  45  to be inserted by squeezing and compression until the top coupling portion  41  is in contact with the top rim  31 . And the exposed sealing ring  45  is squeezed between the annular jutting portion  43  and the inner wall of the container  30  to isolate the internal space of the container  30  from the exterior to form a sealed condition. Through the moving flange  42  the cover  40  can be easily moved upwards and separated from the opening of the container  30 . 
     While the blade type sealing ring  45  allows the opening of the container  30  to maintain the original shape, the air vent  46  for air discharging damages the sealing effect. Moreover, the sealing covers previously discussed provide only sealing function, but do not provide vacuuming function for the interior of the container. 
     SUMMARY OF THE INVENTION 
     The primary object of the present invention is to provide a sealing cover to be used on a container without the need of providing jutting anchor portions thereon. Sealing elements also do not need air vents. It can form a sealed condition for containers with any shape of opening. The sealing effect is more secured. The shape of the container opening also can be maintained intact. When in use there is no alignment problem, thus is more convenient. 
     Another object of the invention is to provide a sealing cover that also can provide vacuuming function. Through a vacuum means the air in the container can be drawn out to form a vacuum condition in the interior. The invention also provides a double seal ring design to make sealing effect more secured to maintain the vacuum condition in the container. Therefore goods held in the container have a longer preservation period. 
     The invention provides a cover to seal a container. It has the following features: an annular jutting portion is provided at a lower side of the cover to be inserted in an opening of the container with a top coupling portion formed on the periphery thereof; an annular seal ring is provided to surround the annular jutting portion that has two blades extended outwards to form a first seal ring fastened to the surface of the top coupling portion and a second seal ring close to the top end of the annular jutting portion; a coupling opening is formed on the surface of the cover which has at least one air vent around the coupling opening; and an air permeable parasol valve is provided and installed on the coupling opening. 
     In one aspect the annular jutting portion has an outer diameter slightly smaller than the opening of the container so that after the annular jutting portion is inserted in the opening the second seal ring is squeezed between the annular jutting portion and an inner wall of the container to isolate the internal space of the container from the exterior to form a sealed condition, and the first seal ring is squeezed between the top coupling portion and the top rim of the opening of the container. 
     In another aspect the top coupling portion further has an annular groove surrounding the jutting annular portion to be wedged in by the first seal ring so that the top coupling portion and the surface of the first seal ring form a flat surface. 
     In yet another aspect the air permeable parasol valve includes a flange blade covering the upper side of the air vent, a depressing portion located above the flange blade and a retaining portion located below the flange blade to be coupled with the coupling opening to fasten the air permeable parasol valve. 
     In yet another aspect the air permeable parasol valve provides air discharge function to facilitate capping of the cover on the container opening. And an air suction means can be disposed to draw the air in the container through the air permeable parasol valve to vacuum the interior of the container. Through the first seal ring a secured sealing effect can be achieved without the concern of deformation that might occur to the second seal ring. And the vacuum condition in the container can be maintained securely by the cover. 
     In yet another aspect the top coupling portion has a moving flange extended from a selected location to facilitate upward removing of the cover to separate the cover from the container opening. 
     In yet another aspect the depressing portion and the flange blade are joined at a juncture which has an indented bending trough formed thereon to facilitate warping up of the flange blade to be moved away from the air vent. 
     In yet another aspect the cover has an indented recess on the top surface with the coupling opening formed thereon to facilitate installation of the air suction means to perform air drawing operation. 
     By means of the construction set forth above, the invention provides at least the following advantages: through the double sealing structure of two blade types seal rings the exterior of the container does not have to provide jutting means for anchoring, and there is no restriction on the shape of the container opening; no alignment for coupling is needed when in use; and operation is easier. Through the air permeable parasol valve which can release air, no air vent is required on the seal rings. Thus an improved sealing effect can be achieved. Through the air permeable parasol valve the air in the container can be drawn out through an air suction means to form a vacuum condition in the container. 
     In addition, as the second seal ring squeezed between the annular jutting portion and the inner wall of the container might be deformed after vacuuming and result in air leakage, the first seal ring can provide a more secured sealing effect due to a tighter compression between the cover and the container after vacuuming. Hence any gap that might occur between the annular jutting portion and the inner wall of the container and due to thickness accuracy of the second seal ring does not make significant impact to the overall sealing effect. Hence the problem of air leakage resulting from the second seal ring after vacuuming can be overcome. Fabrication also is simpler. 
     The foregoing, as well as additional objects, features and advantages of the invention will be more readily apparent from the following detailed description, which proceeds with reference to the accompanying drawings. The embodiments discussed below are merely for illustrative purpose, and shall not be deemed as the limitation of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded view of a conventional sealing cover and a container. 
         FIG. 2  is an exploded view of another conventional sealing cover and a container. 
         FIG. 3  is a perspective view of the sealing cover of the invention. 
         FIG. 4  is an exploded view of the sealing cover of the invention. 
         FIG. 5  is a sectional view of the sealing cover of the invention. 
         FIG. 6  is a sectional view of another embodiment of the sealing cover of the invention. 
         FIG. 7  is a sectional view of the sealing cover of the invention coupling with a container in a use condition. 
         FIG. 8  is a sectional view of the sealing cover of the invention coupling with a container in a use condition for vacuuming. 
         FIG. 9  is a sectional view of the sealing cover of the invention coupling with a container in a use condition for releasing pressure. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Please refer to  FIGS. 3 ,  4  and  7 , the sealing cover according to the invention aims to be used on a cover  100  to seal a container  300 . The cover  100  includes features as follow: an annular jutting portion  130  located at a lower side thereof to be coupled with an opening of the container  300 . The annular jutting portion  130  has a top coupling portion  110  on the periphery that further is extended to form a moving flange  120  at a selected location to facilitate moving upward of the cover  100  to be separated from the opening of the container  300 . 
     The annular jutting portion  130  is surrounded by a seal ring  200  at an outer side. The seal ring  200  has two blade type rings extended outwards including a first seal ring  210  and a second seal ring  220 . The first seal ring  210  is fastened to the surface of the top coupling portion  110  and the second seal ring  220  is close to a top end of the annular jutting portion  130  (also referring to  FIG. 5 ). In practice the top coupling portion  110  further has a groove  111  surrounding the annular jutting portion  130  to be wedged in by the first seal ring  210  so that the top coupling portion  110  and the surface of the first seal ring  210  form a flat surface (referring to  FIG. 6 ). 
     The jutting annular portion  130  has an outer diameter slightly smaller than the inner diameter of opening of the container  300  so that after the annular jutting portion  130  is inserted in the opening of the container  300  the second seal ring  220  is squeezed between the annular jutting portion  130  and an inner wall of the container  300 . The first seal ring  210  also is squeezed between the top coupling portion  110  and a top rim  310  at the opening of the container  300  so that the internal space of the container  300  is isolated from the exterior to form a sealed condition. 
     The cover  100  has a coupling opening  102  on the surface and at least one air vent  103  around the coupling opening  102 , and an air permeable parasol valve  160  coupled on the coupling opening  102  to control air intake and discharge between the container  300  and the exterior. The air permeable parasol valve  160  includes a flange blade  161  formed at a width to cover an upper side of the air vent  103  to be in contact closely with the surface of the cover  100 , a depressing portion  162  above the flange blade  161  and a retaining portion  163  below the flange blade  161  to be inserted into the coupling opening  102 . For assembly the air permeable parasol valve  160  is forcefully inserted in the coupling opening  102  through the retaining portion  163  which is latched on a lower side of the cover  100  to form anchoring. Moreover, the depressing portion  162  and the flange blade  161  are joined at a juncture which has an indented bending trough  164  to allow the flange blade  161  to be easily bent and warped upwards through the depressing portion  162  so that the flange blade  161  can be separated from the air vent  103  at the upper side to allow the interior of the container  300  to communicate with the exterior. 
     Referring to  FIG. 7 , to cap the cover  100  on the opening of the container  300 , insert initially a portion of the annular jutting portion  130  in the opening of the container  300 , the second seal ring  220  is squeezed between the annular jutting portion  130  and the inner wall of the container  300 . At this moment the pressures inside and outside the container  300  are unbalanced, hence it is difficult to cap the cover  100  and the annular jutting portion  130  cannot be fully inserted in the opening of the container  300 . Through the air release function of the air permeable parasol valve  160 , the depressing portion  162  can be depressed to warp the flange blade  161  upwards, and the pressures inside and outside the container  300  can be balanced through the air vent  103  of the cover  100 . Then the annular jutting portion  130  and the second seal ring  220  can be inserted continuously through the opening of the container  300  until the first seal ring  210  at the top coupling portion  110  presses the top rim  310  of the opening of the container  300 . When the depressing portion  162  is released the cover  100  isolates the internal space of the container  300  from the exterior to form a sealed condition through the first seal ring  210  and the second seal ring  220  that are made from elastic material. 
     Refer to  FIG. 8 , the cover  100  further has an indented recess  101  on an upper surface with the coupling opening  102  formed thereon. A hand-driven air suction means  400  can be mounted on the recess  101  to draw air. During vacuuming (such as drawing air through the hand-driven air suction means  400  on the recess  101 ) the flange blade  161  is lifted upwards due to airflow movement so that the air in the container  300  can be drawn out through the air vent  103 . When the interior of the container  300  has reached a desired vacuum condition, and air drawing operation is no longer needed, the flange blade  161  on the air permeable parasol valve  160  rests closely on the upper side of air vent  103  under pressure to maintain the interior of the container  300  in a desired vacuum condition. Hence goods held in the container  300  can have a longer preservation time period. Moreover, as the second seal ring  220  squeezed and deformed between the annular jutting portion  130  and the inner wall of the container  300  could create air leakage in the vacuum condition, the first seal ring  210  is squeezed and compressed more tightly between the top coupling portion  110  and the top rim  310  of the container  300  in the vacuum condition, hence any gap that might exist between the annular jutting portion  130  and the inner wall of the container  300 , and the thickness accuracy of second seal ring  220  do not have significant impact to the vacuum condition. As a result, air leakage problem through the second seal ring  220  can be prevented. The double layers sealing structure thus formed also can be fabricated easier. 
     Refer to  FIG. 9  for the invention in a condition to release the pressure. When there is a desire to open the cover  100 , depress the depressing portion  162  of the air permeable parasol valve  160 . The flange blade  161  is deformed under the downward pressure of the depressing portion  162  to be separated from the air vent  103  on the recess  101 . Then external air can smoothly enter the container  300 , and the cover  100  can be opened easily. 
     The sealed cover of the invention can be used on various sizes of containers. Air in a large container can be directly drawn out while smaller containers held in the large container can release the air to the large container to be drawn out through the large container. Thus the containers located inside and outside can be vacuumed as desired. 
     While the preferred embodiments of the invention have been set forth for the purpose of disclosure, modifications of the disclosed embodiments of the invention as well as other embodiments thereof may occur to those skilled in the art. Accordingly, the appended claims are intended to cover all embodiments which do not depart from the spirit and scope of the invention.