Abstract:
A vacuum lid for sealing a container. The vacuum lid is adapted to seal a container. The lid has a knob, either a twist knob or a push-pull knob, which, when twisted or pushed, forces air inside the container out through evacuation ports. This creates a vacuum inside the container, which aids in maintaining freshness of consumable foods or other substances that degrade over time in the presence of air.

Description:
BACKGROUND INFORMATION 
       [0001]    Field of the Invention 
         [0002]    The invention relates to the field of lids for food and other types of containers. More particularly, the invention relates to vacuum lids. 
         [0003]    Discussion of the Prior Art 
         [0004]    It has long been a problem to keep foods fresh, after the container has been opened. This is particularly an issue with coffee, because the very desirable aroma of the coffee dissipates when the coffee is exposed to air over a period of time. Today, coffee is typically sold in containers or packages that initially have a vacuum seal. The seal is broken, however, once the container or package is opened. 
         [0005]    What is needed is a vacuum lid that is inexpensive to manufacture and that effectively and repeatedly provides a vacuum seal on the container. 
       BRIEF SUMMARY OF THE INVENTION 
       [0006]    The invention is a vacuum lid that may be used to provide a vacuum seal on a food container or other type of container. The discussion of the vacuum lid may hereinafter refer to a food container, but it is also understood, that the lid may be used to provide a vacuum seal on containers in general, regardless of the contents. Paint, for example, is a substance that degrades when exposed to air, and providing a container with a vacuum lid would be beneficial here, too. 
         [0007]    The vacuum lid according to the invention has a housing with air ports in it. A rigid plate is assembled within the housing, such that there is an air-tight seal around the perimeter of the plate where it contacts the inner perimeter of the housing. The rigid plate is mounted such, that it is movable in a vertical direction. An actuation means, such as a twist knob or a push-pull knob, is assembled in the housing and is used to move the rigid plate downward. In so doing, air is forced from the container out through the air ports, creating a vacuum. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    The present invention is described with reference to the accompanying drawings. In the drawings, like reference numbers indicate identical or functionally similar elements. The drawings are not drawn to scale. 
           [0009]      FIG. 1  is a cross-sectional view of a twist embodiment of the vacuum lid according to the invention, showing the lid closed. 
           [0010]      FIG. 2  is a cross-sectional view of the embodiment of  FIG. 1 , showing the lid open. 
           [0011]      FIG. 3  is a elevation plan view of the lid and twist knob, showing the rigid plate beneath the lid flange. 
           [0012]      FIG. 4  is cross-sectional view of the twist knob and threaded shaft. 
           [0013]      FIG. 5  is a top plan view of the lower housing. 
           [0014]      FIG. 6  is a perspective view of the lower housing. 
           [0015]      FIG. 7  is a plan elevation view of the lower housing. 
           [0016]      FIG. 8  is a bottom plan view of the lower housing. 
           [0017]      FIG. 9  is a cross-sectional view of the push-pull embodiment of the lid according to the invention, showing the lid in a closed or sealed state. 
           [0018]      FIG. 10  is a cross-sectional view of the embodiment of  FIG. 9 , showing the lid in a closed or sealed state. 
           [0019]      FIG. 11  illustrates a container with the lid according to the invention and an activation handle for activating a bladder inside the container. 
           [0020]      FIG. 12  is a view in cross-section, showing the handle and the bladder in a container with the lid according to the invention. 
           [0021]      FIG. 13A  is a side view of the container with a flexible upper section and rigid lower section with the lid. 
           [0022]      FIG. 13B  is a cross-section view of the container with a flexible upper section that is compressed into the rigid lower section with the lid. 
           [0023]      FIG. 14  is perspective view of the lid and container with the flexible upper section and rigid lower section. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0024]    The present invention will now be described more fully in detail with reference to the accompanying drawings, in which the preferred embodiments of the invention are shown. This invention should not, however, be construed as limited to the embodiments set forth herein; rather, they are provided so that this disclosure will be complete and will fully convey the scope of the invention to those skilled in the art. 
         [0025]      FIGS. 1-10  illustrate a vacuum lid device  100  according to the invention. The vacuum lid  100  comprises an upper housing  14 , a lower housing  12 , a lid flange  141 , seal means  20 , and an actuation means  30 . The seal means  20  is assembled within the lower housing  12  and the actuation means  30  movably engages with the seal means  20 , so as to selectively create and release a seal within the lid device  100 . In the embodiment shown, the upper housing  14  and the lid flange  141  are a single integrated component. The upper housing  14  and lower housing  12  are fixedly fastened to each other after the seal means  20  and actuation means  30  have been assembled. 
         [0026]      FIGS. 1-4  illustrate a first embodiment of the lid device  100  in which the actuation means  30  is a twist mechanism;  FIGS. 5-8  illustrate details of the lower housing  12 ; and  FIGS. 9 and 10  illustrate a second embodiment, in which the actuation means is a push-pull mechanism. The lower housing  12  is common to both embodiments. 
         [0027]      FIGS. 1 and 2  show the lid device  100 , in a closed or sealed state and in an open or unsealed state, respectively. Various methods of providing a sealed connection between a lid and a container are known and any of such suitable methods may be applied here. For example, a rubber or rigid ring  50  may be used to seal the lid device  100  to a container. See  FIGS. 11 and 12 . The ring  50  is dimensioned to have a stretch fit over the edge of the container and the circumferential edge of the lid  100  and snaps into place, thereby providing an air-tight seal of the lid with the container. 
         [0028]    The lid flange  141  is fixedly connected with the upper housing  14 , which has a circumferential wall  142  that extends upward from the flange  141 . Evacuation ports  143  are provided in the circumferential wall  142 . A threaded bore  144  for receiving the actuation means  30  extends through the center of the upper housing  14 . 
         [0029]      FIGS. 5-8  illustrate details of the lower housing  12 , which encloses the seal means  20 . The lower housing  12  has a lower housing wall  121  extending upward from a horizontal base  123 . Air passageways  122  are provided in the housing wall  121  and air evacuation ports  125  provided in the base  123  as through-holes that extend through a bottom surface  124  of the base  123 . In the embodiment shown, the evacuation ports  125  are evenly spaced about the bottom surface  124 . 
         [0030]    The seal means  20  includes a main seal  21 , a first O-ring  22 , a second O-ring  23 , and a filter  25 . The O-ring fit into respective seal grooves in the lower housing  12 , as shown in  FIG. 5 . 
         [0031]    The actuating means  30  in this first embodiment is a twist mechanism that includes a twist knob  31 , a threaded shaft  33 , and a rigid plate  26  that is affixed to a lower end of the threaded shaft  33 . An easily grippable edge  32  may be provided around the perimeter of the twist knob  31 . The twist knob  31  is movably connected with the upper housing  14  by means of the threaded shaft  33  in the threaded bore  144 . by twisting the twist knob  31 , the rigid plate  26  is forced either downward against the seal means  20  in the lower housing, thereby forcing air out through the various evacuation ports  143  and creating a seal, or upward away from the seal means, thereby releasing the seal and allowing air to flow into the container. The actuation means  30  in this first embodiment is a twist knob  31  that is attached to a rigid plate  26  and a main seal  21  by means of a fastener. Twisting the knob  31  in clockwise direction forces the rigid plate  26  down against the main seal  21 . When the maximum downward motion is reached, the main seal  21  makes contact with a first O-ring  1  and a second O-ring  2 , thereby creating a seal. The rigid plate  26  ensures a uniform support for the main seal  21 . The downward motion forces air from the container up through the evacuation ports  125  in the bottom of the lower housing  12 , through the main seal/filter  25  into the upper housing  14 , where it escapes through the various evacuation ports  143 . A counter clockwise motion of the twist knob  31  breaks the seal by pulling the rigid plate  26  away from the seal means  20 . This allows air to rush through the device into the container, which then allows the container to be open easily. 
         [0032]      FIGS. 9 and 10  illustrate a second embodiment of the vacuum lid device  100 , in which the actuation means  30  is a push-pull mechanism. The lower housing  12  and seal means  20  are as described above for the first embodiment. A rigid or semi-rigid plate  26  is affixed to the upper face of the main seal  21 . The push and pull mechanism is a one way valve construction that evacuates air in the sealed container by manually pressing on the actuation means, somewhat like a bellow or a plunger. Pressing on the push-pull knob  35  causes the main seal  21  to flex, which in turn causes air to escape out from the container. 
         [0033]    This activation may also be accomplished by adding a bladder system  40  to the container. A bladder  44  lines the container and a handle  42  is connected to a plate  46 . The handle  42  extends through the lid flange and the plate  46  is provided beneath a bottom surface of the bladder  44 . See  FIGS. 11 and 12 . Pulling up on the activation handle  42  causes the bladder  44  to compress in the direction of the lid, thereby forcing air within the container to travel upward, which causes the main seal to flex upward, expelling air from the container out through the lid device  100 . A single pull on the activation handle  42  creates the seal. Pushing on the activation handle presses the bladder downward, at which point, external air flows back into the container. The main seal  21  reverts to its original position, in which it has contact with the two O-rings  22  and  23 . This effectively creates a double seal which prevents any external air from re-entering the bladder  44 . The pull knob  35  is used to manually break the seal. As the knob is pulled in an upward motion, the seal with the O-rings  22  and  23  is broken, allowing air to re-enter the bladder  44 . Once the air refills the bladder  44  the container can be easily opened. 
         [0034]    This second embodiment may also be used with a container  60  that has a flexible upper shell  62  and a rigid lower shell  64  as shown in  FIGS. 13A-14 , instead of the bladder system  40 . A connector  66  joins the upper shell  62  to the lower shell  64 . Pressing on the push-pull knob  35  causes the flexible upper shell  62  to compress as air escapes from the container until the flexible upper shell comes into contact with the contents of the container or the bottom of the rigid lower shell  64 , at which point all or nearly all air is expelled and the seal is created. Pulling on the push-pull knob  35  breaks the seal.  FIG. 13B  illustrates the lid  100  and flexible upper shell  62  pressed part way into the lower rigid shell  64 . 
         [0035]    In both embodiments, the main seal  21  and the rigid plate  26  are connected the actuation means  30 . There are various suitable ways of doing this. One way is to provide a shaft on the rigid plate that extends up into a bore in the twist knob or the push-pull knob and to fasten it with a screw or a rivet. 
         [0036]    It is understood that the embodiments described herein are merely illustrative of the present invention. Variations in the construction of the vacuum lid may be contemplated by one skilled in the art without limiting the intended scope of the invention herein disclosed and as defined by the following claims.