Patent Publication Number: US-6659302-B2

Title: Leak proof coffee mug lid

Description:
TECHNICAL FIELD 
     The present invention relates to coffee mug lids in general. More specifically to a lid that has a spring loaded, gasketed valve that opens when a finger twist knob is rotated permitting coffee to be released from the mug and sealed when rotated in reverse. 
     BACKGROUND ART 
     Previously, many types of lids have been used in endeavoring to provide an effective means to enclose a coffee mug or cup. In the past coffee mugs and cups are normally sealed by the use of a resilient cover that snaps over a rim on the top and must be manually removed and replaced. Some mugs have lids that include some type of valve or release mechanism permitting the user to seal the mug when not in use. 
     A the prior art listed below did not disclose any patents that possess any of the novelty of the instant invention, however the following U.S. patents are considered related: 
     
       
         
           
               
               
               
               
             
               
                   
                   
               
               
                   
                 Patent Number 
                 Inventor 
                 Issue Date 
               
               
                   
                   
               
             
            
               
                   
                 Des. 346,933 
                 Denny et al. 
                 May. 17, 1994 
               
               
                   
                 Des. 362,156 
                 Goto et al. 
                 Sep. 12, 1995 
               
               
                   
                 Des. 362,369 
                 Bridges 
                 Sep. 19, 1995 
               
               
                   
                 Des. 373,051 
                 Kramer et al. 
                 Aug. 27, 1996 
               
               
                   
                 Des. 386,948 
                 Wissinger 
                 Dec. 02, 1997 
               
               
                   
                 Des. 396,777 
                 Inoue 
                 Aug. 11, 1998 
               
               
                   
                 Des. 398,187 
                 Parker 
                 Sep. 15, 1998 
               
               
                   
                 Des. 411,713 
                 Bridges 
                 Jun. 29, 1999 
               
               
                   
                 Des. 416,757 
                 Ginuntoli 
                 Nov. 23, 1999 
               
               
                   
                 Des. 425,758 
                 Freed 
                 May. 30, 2000 
               
               
                   
                 4,754,888 
                 Letsch et al. 
                 Jul. 05, 1988 
               
               
                   
                 5,249,703 
                 Karp 
                 Sep. 05, 1993 
               
               
                   
                 5,918,761 
                 Wissinger 
                 Jul. 06, 1999 
               
               
                   
                   
               
            
           
         
       
     
     Letsch et al. in U.S. Pat. No. 4,754,888 discloses a carafe with an inner container surrounded by a casing. The inner container and the casing have an opening at the top which may be closed by a separate plug. The plug and opening in the container and casing are shaped such that it is possible to fill or empty the inner container while the plug is still in the opening. The plug and container both have mating grooves that provide opposed flow paths into and out of the container. The container also includes a basin around the top for receiving coffee from a coffee maker and the plug has openings to provide a flow path from the basin into the container interior. 
     Karp in U.S. Pat. No. 5,249,703 teaches a travel mug that includes a container and a lid in combination. The container has a handle and an annular lip that has an annulus capable of forming a seal with the top side of the annular lip. A cylindrical well in the lid has a vertical dividing wall such that the lid may be readily rotated by hand. The retaining arms extend from the underside of the lid and engage the underside of the annular lip to pull it into tight abutment. Diametrically opposed gaps in the lip act as passageway for the retaining arms. Similarly diametrically opposed notches in the lid align with the gaps to allow liquid to be poured from the container. 
     U.S. Pat. No. 5,918,761 issued to Wissinger is for an insulated container and cover combination that has an outer container shell terminating at an opening with a surrounding edge. An inner container shell is nested within the outer container shell and has an opening surrounded by a continuous edges in abutment with the surrounding edge. The inner container shell is spaced inwardly and is out of contact with the outer shell. A cover mounting assembly is attached to the outer shell adjacent to the opening. A single seal, made of elastomeric material, has a sealing surface disposed at the interface of the shells. Locating rings define the removable cover mounting assembly and locate the single sealing ring on the inner and outer shells. 
     For background purposes and as indicative of the art to which the invention is related reference may be made to the remaining cited design patents. 
     DISCLOSURE OF THE INVENTION 
     Many types of mug lids are in common use today particularly with the wide acceptance of stainless steel and dual wall plastic mugs in a myriad of configurations. Liquids such as coffee, tea and hot chocolate etc. are often carried in mugs throughout the day and even when traveling in vehicles. Song with the difficulty of keeping the liquid hot, spillage is probably the larger obstacle to overcome. 
     It is therefore a primary object of the invention to provide the public with a lid that is continually, sealed until manually opened by a deliberate act of twisting a finger knob. This invention provides a liquid tight seal, under spring pressure, with a gasket continually forced onto a valve seat such that if the mug is inadvertently tipped over no liquid will be released from the mug. There are many other types of lids available in today&#39;s market that have openings with covers but if tipped over, particularly if they remain horizontal, have a tendency to leak and spill coffee or other staining liquids onto the surface. Most lids in this category have sliding valves that are operated by hand or small caps that hinge out of the way however true liquid tight seals are uncommon or require extensive manual manipulation to accomplish such a union. 
     An important object of the invention is that it is easy to understand its operation as one simply rotates the finger twist knob in a clock wise direction and the lid opens and stays open until it is twisted in the reverse direction when the lid automatically reverts to its normally closed and sealed position with the spring tension assuring a tight seal. Indicia located on the top of the dome indicate the position of the valve in a universal manner with symbols or written words in the language used. 
     Another object of the invention is that the mug may be used in any orientation, that is to say, once the valve is opened the mug may be turned in any direction relative to the handle and the coffee or liquid is always available around the lip. This object is realized by the use of a series of outlet ports completely around the raised lip of the lid. The liquid always remains level therefore if the mug is tipped in the drinking attitude the liquid will flow from the appropriate set of ports regardless of where the handle is positioned. 
     Yet another object of the invention is its ability to be cleaned easily. Cleaning is particularly simple as the lid may be emerged in water and cleaning inside is a simple matter of allowing the water to dissolve the residue inside. The valve may be open or closed during this cleaning procedure however it is more thorough if the lid is in the open position as the interface of the gasket to the lid body seat would be cleaned. The compression spring is fabricated of stainless steel and the balance of the lid is thermoplastic which will not rust or deteriorate. 
     Still another object of the invention is that it has few moving parts which interface with each other and the material has ample structural integrity to eliminate breakage and undue wear. 
     A final object of the invention is that it easy to manufacture since few parts are used and it is not difficult to assemble making it cost effective to produce. 
    
    
     These and other objects and advantages of the present invention will become apparent from the subsequent detailed description of the preferred embodiment and the appended claims taken in conjunction with the accompanying drawings. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a partial isometric view of the preferred embodiment. 
     FIG. 2 is a side elevation view of the preferred embodiment. 
     FIG. 3 is a top elevation view of the preferred embodiment. 
     FIG. 4 is a bottom view of the preferred embodiment. 
     FIG. 5 is a partial isometric view of the coffee mug lid body of the preferred embodiment, completely removed from the invention for clarity. 
     FIG. 6 is a partial isometric view of the compression spring of the preferred embodiment, completely removed from the invention for clarity. 
     FIG. 7 is a partial isometric view of the valve plate of the preferred embodiment, completely removed from the invention for clarity. 
     FIG. 8 is a partial isometric view of the valve seat gasket of the preferred embodiment, completely removed from the invention for clarity. 
     FIG. 9 is a partial isometric view of the finger twist knob of the preferred embodiment, completely removed from the invention for clarity. 
     FIG. 10 is a partial isometric view of the push ring gasket of the preferred embodiment, completely removed from the invention for clarity. 
     FIG. 11 is a fragmentary plan view of the top of the lid body illustrating the open/closed indicating symbols. 
     FIG. 12 is a partial isometric view of the valve guide plate of the preferred embodiment, completely removed from the invention for clarity. 
     FIG. 13 is an exploded isometric view of the preferred embodiment. 
    
    
     BEST MODE FOR CARRYING OUT THE INVENTION 
     The best mode for carrying out the invention is presented in terms of a preferred embodiment. This preferred embodiment is shown in FIGS. 1 thorough  13  with the coffee mug lid  20  comprising a lid body  22  that has a centralize aperture  24  therethrough. The aperture  24  includes a number of valve positioning indexing shoulders  26  located on the side walls of the aperture  24 . The lid body  22  also includes a plurality of outlet ports  28  that are located adjacent to the periphery of the body for dispensing liquid or coffee therefrom as shown in FIG.  3 . 
     The body  22  is configured with a peripheral raised lip  30  on the outside and is shaped with a centrally positioned recessed dome  32  on the top surface. The outlet ports  28  are aligned in a circle between the lip  30  and the dome  32  with the apex of the dome containing the centralized aperture  24 . A valve seat  34  is formed into the bottom of the body  22  and provides a uniform sealing surface underneath. 
     A plurality of threads  36  are formed around a lower side of the lid body  22  and provide a convenient interface with like threads on a conventional coffee mug. Indicia  38 , preferably in the form of a raised circular symbol and a raised circular symbol with a dot in the middle, indicate the position of being open or closed. Other types and shapes of symbols or lettering may optionally be employed, in the language of use, for position indication. The lid body aperture  24  includes a plurality of attachment finger slots  40 , as illustrated in FIG. 5, that are indented into the body  22 . 
     A valve guide plate  42  is utilized to provide a stabilization and direction to the lids moving parts. The guide plate  42  is shown by itself in FIG.  12  and includes a push ring guide bore  44  in the middle. The guide plate  42  is disposed within a bottom portion of the centralized aperture  24  and an upstanding spring retaining boss  46  is integrally built into the guide plate  42  with the guide bore  44  forming the inside surface of the boss  46 . 
     The guide plate boss  46  has a compression spring  48  disposed upon the bosses outside diameter to provide the force for sealing liquid within the coffee mug when in the lid is in the closed position. The compression spring  48  is fabricated of stainless steel and is well known in the art and is readily available. The valve plate  42  includes a plurality of attachment fingers  50 , preferably three, as shown in FIG. 12, with the fingers interfacing with the body finger slots  40  in the aperture  24  of the lid body  22 . 
     A gasketed valve plate  52  has a push ring  54  that protrudes upwardly from the center of the valve plate  52 . The push ring  54  is slideably positioned within the guide plate push ring guide bore  44  and centers the valve plate  52  within the coffee mug lid  20 . The valve plate  52  has a valve seat gasket groove  56  on a bottom lower portion of the valve plate  52  and a push ring gasket groove  58  is located in the push ring  54 . A valve seat gasket  60  is retained in the valve seat gasket groove  56  and a push ring gasket  62  is retained in the push ring gasket groove  58 . The valve seat gasket  60  seals the valve plate  52  to the body  22  when coffee mug lid is in a closed position. The push ring gasket  62  seals the valve plate  52  to the guide plate  42  forming a leak proof joint when the lid is in the closed position. 
     The valve seat gasket  60  and the push ring gasket  62  may be formed of a resilient material including natural rubber, synthetic rubber and flexible thermoplastic, including silicone, neoprene, and viton or the like. 
     A spring loaded finger twist knob  64  is rotatably located within the top portion of the centralized aperture  24 . The twist knob  64  includes a plurality of manual rotation tabs  66  protruding from the knobs top providing a gripping surface to rotate the twist knob  64  with ones fingers. Further the twist knob  64  has a plurality of outwardly protruding positioning lugs  68  interfacing with the lid body aperture indexing shoulders  26  for limiting and controlling rotational movement of the knob an also for holding the knob  64  in place in the aperture  24 . 
     The lid body  22 , valve guide plate  42 , valve plate  52  and said finger twist knob  64  are formed of a thermoplastic such as of cellulose, phenolic, phenylene oxide, polycarbonate, polyester, polyethylene, polypropylene, polystyrene, acetyl, polyester, phenylene oxide, polymide or poly vinyl chloride. 
     In operation, the coffee mug lid  20  is screwed onto a conventional coffee mug and functions as follows: when the twist knob  64  is rotated within the indexing shoulders  26 , the valve plate  42  is urged down, against spring compression, disengaging the valve plate  42  from the lid body  22  creating a flow path around the valve plate  42  and through the outlet ports  28 . The opening of the flow path permits coffee, or the liquid within the mug, to be supplied to the user. When the twist knob  64  is rotatably reversed the valve plate  42  returns to its at rest position with gasketed securement of liquid, in a leak proof manner, within the mug. 
     It should be noted that when the lid  20  is assembled and the twist knob  64  is permanently attached to the valve plate  52 , the spring  48  is compressed forcing continual intimate engagement of the valve seat gasket  60  to the valve seat  34  on the bottom of the lid body  22  effectively sealing the liquid in the mug. The seal is only broken when the finger twist knob  64  is rotated as indicated by the position of the rotation tabs  66  in relation to the indicia  38 . It may be clearly seen that the operation is easy and obvious in its functional procedure. 
     While the invention has been described in complete detail and pictorially shown in the accompanying drawings, it is not to be limited to such details, since many changes and modifications may be made to the invention without departing from the spirit and scope thereof Hence, it is described to cover any and all modifications and forms which may come within the language and scope of the appended claims.