Abstract:
A sipper cup ( 10 ) includes a valve ( 16 ), when the valve ( 16 ) is not deformed, the valve is in an “off” position, so that no substantial liquid flows, even if the cup is turned upside down.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates to a child&#39;s sipper cup which functions as a weaning aid. The closure for the cup has a valve which is opened with bite or lip pressure, thus preventing the use of a nursing motion to withdraw fluid. The valve is comprised of a flexible material having a durometer hardness range of 60-90 Å.  
       BACKGROUND INFORMATION  
       [0002]     The transition from bottle or breast feeding to drinking from a cup is often a difficult transition for a child. The mechanics of drinking from a cup are initially difficult, and there is the loss of pleasure derived from nursing. To facilitate this transition, it would be useful to have a sipper cup which provides something of the feel of a nipple, yet requires bite or lip pressure rather than a nursing motion to remove fluid from a cup. In nursing, the tongue musculature moves in a backward-forward peristaltic (wave-like) motion, and the tongue must protrude beyond the gums for effective suckling. When bite or lip pressure is required to remove fluid from the cup, nursing is prevented, as bite or lip pressure blocks the tongue from protruding beyond the gums.  
         [0003]     Some cups have been designed with valves that open by pressure of the lips. For example, U.S. Pat. Nos. 4,782,975, 4,828,141 and 4,946,062 disclose a valved spout for a container closure lid. The opening of the valve is a slit and is normally in a closed position. The slit opens by the application of force laterally to the edge of the valve. The valve is formed of flexible and resilient material such as synthetic rubber compositions.  
         [0004]     U.S. Pat. No. 5,730,336 discloses a valve for a flexible liquid container that can be opened by application of pressure from a user&#39;s lips or teeth. The valve comprises an elongated hollow body ending in a diaphragm having at least one slit, the slit being the opening through which liquid is dispensed. When pressure is applied, the slits open and allow fluid to be expelled from the container.  
         [0005]     U.S. Pat. No. 4,350,260 discloses a lid for a drinking cup, the lid comprising a mouthpiece extending upwardly from one peripheral edge of the lid. The mouthpiece fits within the user&#39;s mouth and has a valve that is operable by pressure from the user&#39;s lips or teeth, and which controls the flow of liquid from the container.  
         [0006]     U.S. Pat. No. 6,202,877 discloses a container closed by a lid having a flexible gasket which opens upon application of bite or lip pressure to the gasket.  
         [0007]     However, various problems can be seen in the design of these cups. The valve may prevent complete emptying of the contents of the cup, leading to the possibility of bacterial contamination or the like. The valve may also not prevent leakage when the cup is overturned or dropped by the child. With prolonged use over time, the opposing sides of the valve which form the slit will fail to fully close, leading to further leakage of the cup. Additionally, the cup lid and valve must be comprised of a material that is flexible enough to allow a young child to open the cup with bite or lip pressure, yet be designed in a manner that discourages or prevents nursing from the valve.  
       SUMMARY OF THE INVENTION  
       [0008]     The present invention solves the above need by providing a closure for a sipper cup having a valve that aids in weaning a child from a bottle or breast to a cup. The valve is made from a flexible material such as a thermoplastic elastomer—olefin mixture having unique properties suitable for a child&#39;s cup. The durometer hardness of the flexible material must be within the range of 60-90 Å. Other flexible materials such as natural or synthetic rubbers and silicone may also be used, as long as they have the desired durometer hardness. The valve is openable by bite or lip pressure only. That is, the nursing action of an infant, which produces a 8-10 in. Hg vacuum, will not produce a significant fluid flow. Additionally, the top of the valve, which bows outward when in use, is designed in such a way to ensure complete emptying of the cup, thus preventing contamination. The valve also minimizes leakage or spills if the cup is dropped or overturned.  
         [0009]     It is an object of the present invention, therefore, to provide a sipper cup that aids in weaning a child from a bottle or breast to a cup.  
         [0010]     It is an additional object of the invention to provide a sipper cup that can be operated by pressure of the lips or gums.  
         [0011]     It is a further object of the invention to provide a sipper cup that is comprised of a material having suitable properties for use in a child&#39;s cup.  
         [0012]     These and other objects of the invention will become apparent from the following drawings, the detailed description and the appended claims. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]     The invention is further illustrated by the following non-limited drawings in which:  
         [0014]      FIG. 1  is an isometric view of the closure with a closed valve.  
         [0015]      FIG. 2  is an isometric view of the closure with an open valve.  
         [0016]      FIG. 3  is a cross-sectional view of the closure taken along line  3 - 3  in  FIG. 2 .  
         [0017]      FIG. 4  is an isometric view of the closure on a container.  
         [0018]      FIG. 5  is a cross-sectional view of an alternate embodiment of the closure.  
         [0019]      FIG. 6  is an enlarged cross-sectional view of the closure taken along line  3 - 3  in  FIG. 2  (when spout is in relaxed position).  
         [0020]      FIG. 7  is an enlarged cross-sectional view of the closure taken along line  3 - 3  in  FIG. 2  (when spout is in pinched position).  
         [0021]      FIG. 8  is a cross-sectional view of the closure taken along line  4 - 4  in  FIG. 2 . 
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0022]     As shown on  FIGS. 1 and 2 , a closure  10  for a drinking cup  1  ( FIG. 4 ) includes a skirt  12 , an end wall  14 , and a valve  16 . The skirt  12  depends from the end wall  14 , extending in a downward direction. As shown on  FIG. 3 , the end wall  14  has a first, outer side  18  and a second, inner side  20 . An opening  22  extends through the end wall  14 . Optionally, the end wall  14  has a small opening  58  ( FIG. 1 ) to ease the flow of liquid from the cup and prevent formation of a vacuum. The skirt  12  includes a means to engage the drinking cup  1 . As shown in  FIG. 3 , the means to engage the drinking cup  1  is a lip  24  that is structured to engage a ridge on the cup. The means to engage the drinking cup  1  may be any common coupling structure, such as a snap-fit or screw-on lid.  
         [0023]     The valve  16  is disposed about the opening  22 . The valve  16  extends from the end wall first, outer side  18 . The valve  16  has a first transition portion  30 , an elongated flexible body  32 , a second transition portion  34 , a top  36 , and a slit  38 . The top  36  can be flat, domed or concave, as any shape that can be made compatible with the valve is suitable. The top  36  includes two flexible portions  40 ,  42  ( FIG. 1 ), each about 4 to 5 mm in width and having an outer area,  40 A,  42 A ( FIG. 8 ), a thickened internal bridge  40 B,  42 B ( FIG. 8 ) of a width between about 1 to 2 mm, preferably 0.1 to 0.2 mm, and an inner area  40 C,  42 C ( FIG. 8 ) of a width about 0.5 to 3.5 mm, preferably 1.3 to 1.8 mm. The slit  38  is disposed between the internal bridge  40 B,  42 B and inner areas  40 C,  42 C. The slit  38  is about 5.5. mm long. The outer areas  40 A,  42 A and inner areas  40 C,  42 C of the flexible portions  40 ,  42  have a thickness of not more than about 1.5 mm and not less than about 0.5 mm; preferably the outer areas  40 A,  42 A of the flexible portions and the inner areas  40 C,  42 C have a thickness of about 1.0 to 1.2 mm. The thickened internal bridge has a thickness of about 1.0-2.0 mm, more preferably 1.6 to 1.9 mm, most preferably 1.7 to 1.85. With these dimensions, the flexible portions  40 ,  42  are less likely to become warped after use. Thus, the valve  16  is able to maintain the sealing function longer. In addition, the thickened internal bridge  40 B,  42 B in combination with an inner area  40 C,  42 C of reduced thickness provides the valve with a “snap-back” return upon closing, without loss of flexibility. As used herein, the term “flexible portion” will be used to denote the entire flexible portion of the top of the closure,  40 ,  42 , on either side of the slit  38 , including the thickened internal bridge portions  40 B,  42 B, and the outer areas  40 A,  42 A and inner areas  40 C,  42 C of thinner dimension.  FIGS. 6, 7  and  8  show this aspect of the invention in more detail.  
         [0024]     The flexible portions  40 ,  42  are structured to move between a closed position ( FIG. 1 ) and an open position ( FIG. 2 ). In the closed position, the flexible portions  40 ,  42  have one edge  44 ,  46  abutting the other flexible portion edge  44 ,  46 . That is, the edges  44 ,  46  abut each other and are bisected by the slit  38 . As detailed below, in the second position, the flexible portions  44 ,  46  are bowed outward so that the slit  38  is wider. Both the first transition portion  30  and the second transition portion  34  are slanted away from the end wall  14 .  
         [0025]     The valve  16  is made from a flexible material which is preferably a thermoplastic elastomer—olefin polymer material, although other materials having the desired durometer hardness described below, such as natural or synthetic rubbers or silicone-based materials, are contemplated as being within the scope of the present invention. The elongated, flexible body  32  is preferably shaped as an oval, having two opposing long sides  50 ,  52  and two opposing short sides  54 ,  56 . The slit  38  extends between the long sides  50 ,  52 . In this configuration, when bite or lip pressure, such as could be applied by a child, is applied to the long sides  50 ,  52  of the elongated flexible body  32 , as shown in  FIG. 2  by arrows L-L, the two flexible portions  40 ,  42  move from the first, closed position to the second open position. That is, when a compressive pressure is applied to the oval long sides  50 ,  52 , the flexible portions  40 ,  42  bow outward thereby making slit  38  wider. The nursing action of an infant or child, more specifically the 8-10 Hg vacuum applied in nursing from a breast or bottle, will not produce significant fluid flow from the valve, distinguishing the valve as a true weaning invention. Additionally, as can be seen in the figures, and in particular  FIG. 2 , the design of the valve, that is, having a top  36  in the closed position and flexible portions  40 ,  42  which bow outward in the open position, ensures that substantially all liquid can be removed from the cup when the valve is in the open position. In other words the valve does not “trap” any liquid within the cup.  
         [0026]     As shown in  FIG. 4 , the closure  10  is structured to engage a cup  1 . The cup  1  has a body  2  is structured to hold a liquid. The body  2  cup has a bottom  3 , a sidewall  4 , and an upper opening (not shown). The cup  1  includes a coupling means, such as a thread (not shown) that is structured to engage lip  24 . When the closure  10  is joined to a cup  1 , the cup  1  acts as a sipper cup or weaning aid.  
         [0027]     The material of the valve and cup lid is preferably a thermoplastic elastomer—olefin polymer mixture which imparts unique properties to the sipper cup. For example, the material is rigid enough to allow the lid of the cup to be screwed or snapped onto the cup itself, and yet flexible enough to enable a 10-month old infant to deform the valve with bite or lip pressure. The material also has good tear resistance, so that pieces of the material will not come off in the child&#39;s mouth. This is very important, as it provides an additional safety feature to the cup.  
         [0028]     Preferably, the thermoplastic elastomer—olefin mixture will have a durometer hardness in the range of about 60-90 Å, as measured by the Shore A scale. Any material having a durometer hardness in this range would be suitable for use in the present invention. This hardness range will result in a material having the desired properties discussed above. More preferably, the durometer hardness will be about 75-85 A; and most preferably the durometer hardness will be about 78-80 A.  
         [0029]     The material used in the lid and valve can also be described in terms of the force required to deform the elastomer and cause the valve to open. As the sipper cup is intended for use by a child in the age range of about 10 months to 3 years, the force required to deform the valve must be within the capabilities of a child in this age range. Typically, this will be about 1.5-9.0 newtons, preferably about 4.0-5.0 newtons.  
         [0030]     Any thermoplastic elastomer—olefin mixture can be used, as long as it provides the desired durometer hardness. Suitable thermoplastic elastomers include, for example, those sold under the Versaflex tradename by GLS Corporation of McHenry, Ill. Most preferred is the thermoplastic elastomer sold under the tradename of Versaflex CL-40, by GLS Corporation.  
         [0031]     Similarly, any olefin polymer can be used, as long as it results in a material having the desired durometer hardness. Suitable olefins include, but are not limited to, polyethylene, polypropylene, polyisobutylene, polymethylpentene, and other similar olefins. Most preferred is polypropylene, as it results in a material of superior properties. Preferably, the thermoplastic elastomer and the olefin will be mixed in a ratio of about 8 parts elastomer to about 2 parts olefin, however, the ratio may be between from 6.5-9.5 parts elastomer to about 0.5-3.5 parts olefin. The components are mixed as is well known in the art of injection molding. After the mixture is obtained, the material can be molded in the above described design by methods known in the art.  
         [0032]     An alternate embodiment of the closure  110  is shown in  FIG. 5 . In this embodiment, the end wall  114  and the skirt  112  are separate pieces. The skirt  112  includes a generally circular central opening  111  and a flange  113  that extends radially inward. The end wall  114  is sized to be smaller than the diameter of the skirt  112 , but larger than the generally circular central opening  111 . Thus, the end wall  114  is structured to engage the flange  113 . A seal  115  may be disposed between the end wall  114  and the flange  113 . When the closure  110  engages the drinking cup  1 , the end wall  114  is biased towards the flange  113  thereby making a generally water-tight interface. The valve  116  is disposed on the end wall  114 . The valve  116  is similar to the valve  16  described above.  
         [0033]     Whereas particular embodiments of this invention have been described above for purposes of illustration, it will be evident to those skilled in the art that numerous variations of the details of the present invention may be made without departing from the invention as defined in the appending claims.