Abstract:
The invention provides a shot glass or similar cup for drinking have an outside wall that tapers downwardly outward. The design allows for nesting of cups and thermal insulation of the fluid containing chamber. For aesthetic purposes, construction is with transparent plastic and an array of rings protruding into the inner chamber enhances the appearance of liquids poured therein.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application claims priority from U.S. Provisional Application No. 60/633,359, filed on Dec. 3, 2004; U.S. Provisional Application No. 60/634,953, filed on Dec. 10, 2004; U.S. non-provisional application No. 11/255,572, filed on Oct. 21, 2005; and U.S. design application Nos. 29/241,046 and 29/241,047, both filed on Oct. 21, 2005, all of which are incorporated herein by reference in their entirety. 
     
    
     TECHNICAL FIELD  
       [0002]     The invention relates to drinking vessels.  
       BACKGROUND  
       [0003]     For serving alcoholic beverages, a drinking vessel, commonly know as a shot glass, has been known for some time. These contain a fluid volume that can range from about ⅞ oz. (26 ml) to 1.75 oz (52 ml), with the middle of the range being more common. Typically, these are made of glass of thicknesses ranging from about 1/16 in. (1.5 mm) to as much as ¼ in (6 mm) and the thickness may be variable. The overall height ranges form about 2-3 in. (51-76 mm) with an average diameter ranging from about 1.5-2 in. (38-51 mm). To aid being picked up and held in a hand, the outside walls usually taper upwardly outward. To prevent tipping, some shot glasses are provided with a lower base that is massive compared to the glass and contents. The weight of glass shot glasses ranges from about 2-4 oz. (55-110 g).  
       SUMMARY  
       [0004]     Disclosed, is drinking cup that may be used as an improved shot glass with a chamber having a bottom connected to a chamber side wall extending upwardly from the bottom and terminating in an upper rim that forms the periphery of a generally open top and having a separate supporting side wall extending downwardly from the upper rim with an outward taper and extending at least to the level of the chamber bottom and terminating in a support rim that supports the cup. In a preferred embodiment, the support side wall has slope of about 7 degrees so that pouring fluids into the chamber without tipping the cup is facilitated.  
         [0005]     In one embodiment, the support rim is disposed at least about 0.1 in. (2.5 mm) below the chamber bottom so that the chamber is thermally insulated from a table.  
         [0006]     In another embodiment, there is an array of projections disposed along the chamber wall and projecting into the chamber. These projections preferably have cross sections that are chordal segments of a circle whereby an optical illusion of enlargement is created. Preferably the chordal segments project into the chamber by an amount in the range of 0.002-0.007 in. (0.05-0.2 mm) and, still more preferably, the projected amount is about 0.007 in (0.2 mm) whereby the optical illusion is enhanced.  
         [0007]     In a preferred embodiment, the cup has an inner outline and outer outline matched geometrically match so that two or more cups can be nested in a stack. Preferably, there are nesting stops disposed between the chamber wall and the supporting wall so that 100% nesting is prevented but at least 60% is allowed.  
         [0008]     Although not a limitation on the invention, typically, the liquid volume of the chamber is in the range of about 1 oz. (30 ml) to 1.5 oz. (45 ml) for use as a shot glass.  
         [0009]     In another preferred embodiment, the chamber has a bottom connected to a chamber side wall extending upwardly from the bottom and terminating in an upper rim that forms the periphery of a generally open top. In this one, there is no separate supporting side wall, but the chamber side wall has an outer side that extends downwardly with an outward taper.  
         [0010]     This last embodiment can be produced with all the variations of the separate supporting wall embodiment except for nesting.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]     These and other features, aspects, and advantages of the invention will become better understood after inspection of the following description, claims, and appended drawings wherein:  
         [0012]      FIG. 1A  illustrates a top plan view of a reverse taper drinking cup;  
         [0013]      FIG. 1B  illustrates a cross-section of the cup shown in  FIG. 1A ;  
         [0014]      FIG. 1C  illustrates a bottom plan view of the cup shown in  FIG. 1A ;  
         [0015]      FIG. 1D  illustrates a side elevation view of the cup shown in  FIG. 1A ;  
         [0016]      FIG. 1E  illustrates an enlarged portion of the cross section shown in  FIG. 1B ;  
         [0017]      FIG. 2A  illustrates a cross section of another embodiment of the invention without the space and inter-wall cavity shown in  FIG. 1B ;  
         [0018]      FIG. 2B  illustrates a cross section of still another embodiment of the invention without the surface effects shown in  FIG. 2A ;  
         [0019]      FIG. 2C  illustrates a cross section of another variation which is the embodiment in  FIG. 2B  with the addition of a space;  
         [0020]      FIG. 3A  illustrates a top plan view of a serving tray for one or more of the drinking cups illustrated in  FIGS. 1B and 2C ; and  
         [0021]      FIG. 3B  illustrates a cross-section of the serving tray illustrated in  FIG. 3A . 
     
    
     DETAILED DESCRIPTION  
       [0022]     The invention will now be described with reference to the drawings.  FIG. 1A  shows a top plan view of the invented drinking cup having a chamber  12  with a side wall  18  leading to a top rim  22  that connects to wall  24 . (Herein, “top” and “bottom” refer to the usual gravity determined orientations that apply when drinking cups are used.)  
         [0023]      FIG. 1B  shows a cross section of the cup  11  having the chamber  12  with bottom  14  connected to the side wall  18  on which are surface effects  20  (discussed further below) leading up to the top rim  22 . This is in turn supported by support wall  24  that terminates in a bottom rim  26 . Normally, unless picked up, the cup rests on bottom rim  26 . (The dimple  16  in the center of bottom  14  is a typical injection point when injection molding is used to make the part.) Below chamber  12  is an elevation space  28  and to the side is an inter-wall cavity  30 .  
         [0024]     Preferably, the outline of the outside of the cup  11  substantially matches the outline of the inside of the cup surrounding elevation space  28  and inter-cavity chamber  30 . This makes it possible to nest cups and save on storage space. However, if there is an exact match, separating cups can be difficult due to an attraction between cups. The rib  32  extending below rim  22  between walls  18  and  24  in the notch  30  prevents the apex of the rim  22  from being inserted all the way into the notch  30  of another cup. Preferably, there should be at least three ribs equally spaced around the circumference of the notch  32  as illustrated in the bottom view in  FIG. 1C .  
         [0025]      FIG. 1D  shows a side elevation view with the top rim  22  and a bottom rim  26 . The knurled band  34  is not essential, but provides a finger gripping surface.  
         [0026]     It is well know that, for consumer items, injection molded plastic parts can be made with lesser production costs than many other methods. Typically, a cavity inside a mold having two dies is injected with hot plastic that is allowed to cool and the two dies are pulled apart to let the plastic part fall out. This is not possible for all designs. As is very well known, the dies must define a plane (or planes) through the part that, when viewing the part perpendicularly away from the plane in both directions, no overhanging structure is encountered. The perimeter of such a plane is defined as a parting line. When a cross section of the part is viewed edge-on to the parting line, it forms a single straight line from one extreme edge of the cross-section to the other with no overhangs or undercuts perpendicular to the parting line on either side of it. For any given cross section, CAD/CAM software is available to determine a parting line, if one exists. Thus, a parting line is a geometric construct that limits the design of the part.  
         [0027]     Without the surface effects  20 , the cup illustrated in  FIG. 1B  has a parting line that runs across the bottom, tangent to the rim  26 . This makes it possible to use injection molded plastic construction.  
         [0028]     As is well known by injection molders, to separate the part from the dies, the angle that walls make with respect to the parting line, called draft angles, are preferably at least 0.5°, more preferably 3°. ( FIG. 1B  illustrates draft angles of about 7°.) At the same time, it is highly desirable that, when the two dies are separated, the part is pulled out of the “A” side of the die with the “B” side of the die and then ejected from the B side. The almost universal solution is to provide a small inconspicuous projection, know as a puller, into the B die that provides a slight undercut of about 0.002-0.003 in. (0.05-0.075 mm). Even with the undercut, a thin walled plastic part will deform enough to be ejected from the B die. For this particular design, for some reason, one ring in the volume  12  was found to be not quite enough. It was estimated that two or three rings would be. However, it was decided that it might look interesting to have a continuous complete array  20  of projections cover the entire inside wall to produce a distinctive washboard appearance.  
         [0029]      FIG. 1E  is a 10X cross-sectional enlargement of the circled portion of  FIG. 1B . On the wall  18 , there is an array of projections  21  spaced apart by flat portions of the wall  19 . The need to eject the part from the B die places a limit on how far the projections  21  can extend from the flat portion  19 . The larger the draft angle or slope of the wall  18 , the greater this can be.  
         [0030]     A working example was constructed from injection molded polystyrene. This had a liquid volume of about 1.25 oz. (37 ml). The overall diameter across the top rim  22  was about 1.8 in. (46 mm) and across the bottom rim  26  was about 2.2 in. (56 mm). The rim-to-rim height was about 1.75 in. (44 mm). The overall diameter of the inner chamber was about 1.5 in. (38 mm). It should be straightforward to obtain any desired volume by varying the dimensions.  
         [0031]     In this example, the projections of array  21  were chordal segments of a circle with base of 1/32 in. (0.8 mm) and a projection into chamber  12  of 0.007 in. (0.2 mm). These were spaced on 1/16 in. (1.6 mm) centers so that flat portions of the wall  19  between projections were also 1/32 in. (0.8 mm). The slope of walls  18  and  24  were both about 7°. This reduced the undercut due to the projections to about 0.002 in. (0.05 mm). Fortunately, even with the large number of undercutting rings, the part could still be ejected from the B die.  
         [0032]     In this working example, the thickness of bottom  14  and walls  18  and  24  were all about 0.05 in. (1.3 mm) thickness. The weight of the part was only about 0.7 oz. (20 g).  
         [0033]     Informal tests were run by pouring various fluids into the shot glass. In spite of the light weight, it was very stable and did not tip in response to fluid momentum. Also, surprisingly, when filled with fluid, the chamber  12  looked larger than expected. Most likely, this is due to the array  20  having some sort of optical properties.  
         [0034]     The invention has various other advantages over what is currently available. An example of a non-obvious one is the following. The air space  28  below the chamber  12  acts as a good thermal insulator against the environment. Combined with the thin walls, the fluid in chamber  12  can be kept at a more constant temperature.  
         [0035]     Although the inventors prefer injection molding, consideration should be given to thermoforming as a construction method. It is believed that this would produce a less expensive, but less durable and less attractive cup. When made from injection molded plastic, two materials can be considered. So-called crystal polystyrene is inexpensive and easy to work, but not as durable as polycarbonate. This art is fairly well developed and making the cup should present no difficulty to anyone with ordinary skill in it.  
         [0036]     The shot glass could be made from glass, but the thickness of walls  18  and  24  would usually be more than that shown or indicated and the weight of the cup greater. One of the advantages of the invention is that it is stable, in spite of its light weight. The cup could be made from a variety of materials as this is not critical in some applications.  
         [0037]     Although not essential, the substantially matching inner and outer outlines mean that cups can be stacked. This reduces storage space requirements. The function of the ribs  36  to space apart nested cups can be provided with protrusions in a variety of places on the cup.  
         [0038]      FIG. 2A  illustrates a cross section of another embodiment  11 A of the invention without the space and inter-wall cavity shown in  FIG. 1B . In this case, the base  44  and walls  46  are solid and this design cannot be nested. However, the wall  46  retains the non-traditional downward outward taper of the previous embodiments. Since this design is heavier, it might be advantageous to use the knurled ring  34  that was illustrated in  FIG. 1D . One potential problem is that he projections of the array  20  may have to be reduced because the walls are thicker and less flexible.  
         [0039]      FIG. 2B  illustrates a cross section of still another embodiment  11 B of the invention without the array  20  shown in  FIG. 2A .  
         [0040]      FIG. 2C  illustrates a cross section of another variation  11 C which is the embodiment in  FIG. 2B  with the addition of a space  48  in the bottom base  44 . The use of this particular space is discussed next.  
         [0041]     Another major advantage of some of the embodiments has to do with the difficulty that serving persons have in carrying drinks to patrons in crowded bars. When trays are used, as is often the case, there is always a chance of tipping the serving containers off the tray and losing the drink or worse, drenching a patron.  FIGS. 3A &amp; 3B  illustrate a solution to this problem that may be unique to this shot cup design. As show in  FIG. 3A , a tray  50  is provided that can securely transport one or more cups  11 . In the figure, there is one cup in the center and six disposed on a circle  52 , but the layout is not critical.  FIG. 3B  shows a cross-section with bosses  54  and  58  disposed around the base of the tray  50 . As can be seen, the bosses are shaped to match the inside space  28  of cup  11  or space  48  of cup  11 C. Higher bosses could be used, if necessary.  
         [0042]     Having described the best modes of the invention, several variations can be mentioned. First, the slope of the walls need not be 7°. When made with injection molded plastic, draft angles as small as 0.5°, can theoretically be used. However, a small draft angle would produce a more vertical taper that may not be as stable and would reduce the amount that projections could extend form the inside walls. A nested design may be difficult. On the other hand, slopes much larger than 7° could be clumsy to hold in a hand.  
         [0043]     Second, the cup need not be circular. For example, ovals or polygons could be used. The walls need not be a single segment, but could be stepped as long as undercuts were not too large for molding. Of course, metals cups made on a lathe would have a different set of constraints.  
         [0044]     Third, with respect to nesting, the cups illustrated herein nest up to about 60%, i.e., 40% of a one cup protrudes from the cup below.  
         [0045]     Lastly, although the working example only had a fluid volume of 1.25 oz., the same principles could be applied to larger cups of several ounces or more.  
         [0046]     Having described various embodiments, those skilled in the art will be able to produce equivalents that are within the scope of this invention which is limited only by the appended claims.