Abstract:
A plastic cap has one or more hinged flaps that cover openings in the cap, as well as a stepped sealing ring against which the top of a plastic bottle seals. The sealing ring is stepped, much like the rows of seats in a circular stadium. This stepped arrangement permits the cap to be used with many different bottle rim diameters and automatically corrects any ovality of the bottle rim by forcing it to flex into a more circular shape as it engages the steps of the stepped ring.

Description:
FIELD OF THE INVENTION  
         [0001]    This invention generally relates to hand-held plastic containers for storing and dispensing particulate matter. More particularly, it relates to such containers with a cover having a plurality of flaps for enclosing, respectively, a plurality of openings in the cover. More particularly, it relates to containers for foodstuffs having a shaker opening with a plurality of holes and/or a spooning opening with a large opening adapted to receive a common household spoon.  
         BACKGROUND OF THE INVENTION  
         [0002]    Plastic caps and receptacles for the disposable container industry suffer from certain incompatibilities. Generally speaking, they are considered interchangeable, since they have standard threads and standard major diameters. For this reason, one can expect a nominal “63 mm” cap to handily screw onto a “63 mm” receptacle. Beyond this, however, one cannot be assured of compatibility. Commercial receptacles or bottles typically have recessed shoulders adjacent to their open threaded ends to receive the threaded skirt of the cap. The goal is to screw a cap with an outer circular diameter onto a bottle with the same unrecessed outer diameter, thereby providing a cylindrical container with a constant outer diameter over its entire height. As a result, when one screws a random cap onto a random bottle, the skirt of the cap may interfere with the unrecessed portion of the bottle before the cap is screwed down. This will prevent the cap from being screwed completely down, thereby preventing the sealing surfaces of the cap from completely engaging the sealing surfaces of the bottle.  
           [0003]    In addition to this incompatibility, the diameter and width of the sealing surfaces of the bottle and cap are often different, even when they have the same nominal thread pitch and major diameter. If a manufacturer wishes to make a cap (or bottle) that can be used with the greatest range of bottles (or caps) by other manufacturers, he is compelled to make as wide a sealing surface as possible. Unfortunately, this requires additional plastic.  
           [0004]    There is another problem when manufacturing caps with wide sealing flanges: the propensity of the bottle top to buckle when screwed down too tightly. A wide flange permits force to be applied evenly to the top of bottles with warped sealing surfaces. These bottles have sealing surfaces at their mouths that are not truly circular, but are oval. By screwing a cap down firmly onto the bottle, such as with an automatic capping machine, the oval top begins to buckle, with some portions of the bottle bending inward, and some portions of the bottle bending outward. U.S. Pat. No. 4,693,399, which issued to Hickman (Sep. 15, 1987) purported to solve the ovality problem by providing the cap with a wide, flat sealing surface that was wide enough to accommodate a warped, oval-topped bottle. By providing a wide, flat surface against which the bottle could seal, the top of the bottle could be quite oval, yet there would still be sufficiently wide, flat surface against which it could seal. Unfortunately, this arrangement merely accommodated the out-of-roundness of a warped bottle. The tops of the bottles remained warped. This was an effective solution for hand-tightened caps, but was of quite limited value for machine-attached and tightened caps. Machines for attaching caps to bottles operate at high speeds. It is quite difficult to adjust them to provide a constant tightening torque. As a result the torque applied to seal a cap on bottle will vary significantly in a single production run. Given this wide range of tightening torques, the wide flange of the &#39;399 patent can actual cause bottles to buckle during capping.  
           [0005]    As the cap is tightened, the oval rim of the bottle slides against the wide, flat sealing flange, reducing friction between the rim and the wide sealing flange, making it easier to move axially inward or outward, toward or away from the central axis of the bottle. As a result of this reduced friction, the oval rim of the bottle tends to increase in ovality as the bottle is over-tightened until it either disengages from the threads or the bottle collapses.  
           [0006]    What is needed is an improved cap that can accommodate a wide range of bottle mouth diameters. What is also needed is a cap that can correct (and not accommodate) bottles with warped oval mouths and sealing surfaces. It is an object of this invention to provide such a cap.  
         SUMMARY OF THE INVENTION  
         [0007]    In accordance with a first embodiment of the invention, a circular plastic cap having a longitudinal axis is disclosed, the cap including an end cover, at least one flap integrally formed with the end cover, a cylindrical skirt integrally coupled to the end cover at one end and having a second open end configured to receive the mouth of a receptacle, and a circular sealing ring disposed inside the skirt and adjacent to the end cover, the sealing ring having a plurality of planar sealing surfaces, axially spaced apart, such that each sealing surface has a greater diameter the closer that sealing ring is to the open end of the skirt. Each sealing surface may have an axial width substantially equal to or less than an average thickness of the cap. The sealing ring may include a plurality of substantially right cylindrical surfaces coaxial with the cap disposed between adjacent sealing surfaces.  
           [0008]    Each right cylindrical surface may have a greater diameter the preceding right cylindrical surface as one approaches the open end of the skirt. The sealing ring may be fixed to the end cover. The sealing ring may or may not be fixed to the skirt.  
           [0009]    In accordance with a second embodiment of the invention, a container is disclosed, the container including a receptacle including a right cylindrical sidewall having an externally threaded upper end and a lower end, a bottom integrally formed with the sidewall and enclosing the lower end of the sidewall, wherein the upper end of the receptacle defines a mouth having a mouth sealing surface, and a circular plastic cap having a longitudinal axis, wherein the cap further comprises an end cover, at least one flap integrally formed with the end cover, a cylindrical skirt integrally coupled to the end cover at one end and having a second open end configured to receive the mouth of a receptacle, and a circular sealing ring disposed inside the skirt and adjacent to the end cover, the sealing ring having a plurality of planar sealing surfaces, axially spaced apart, such that each sealing surface has a greater diameter the closer that sealing ring is to the open end of the skirt, wherein one of the plurality of sealing surfaces is engaged with the mouth sealing surface and at least one of the plurality of sealing surfaces is not engaged with the mouth sealing surface. The end cover and the at least one flap may be configured to provide the cap with a substantially flat planar end surface. The at least one flap may be recessed into and flush with the end cover. The cap may further comprise a second flap, wherein the second flap is integrally formed with the end cover. The second flap may be recessed into and flush with the end cover. Each sealing surface may have an axial width substantially equal to or less than an average thickness of the cap. The sealing ring may include a plurality of substantially right cylindrical surfaces coaxial with the cap disposed between adjacent sealing surfaces. Each right cylindrical surface may have a greater diameter than a preceding right cylindrical surface as one approaches the open end of the skirt. The sealing ring may be fixed to the end cover. The sealing ring may not be fixed to the skirt.  
           [0010]    In accordance with a third embodiment of the invention, a method of attaching an sealing a cap to a bottle is disclosed, wherein the cap comprises an end cover; a cylindrical skirt integrally coupled to the end cover at one end and having a second open end configured to receive the mouth of a receptacle, and a circular sealing ring disposed inside the skirt and adjacent to the end cover, the sealing ring having a plurality of planar sealing surfaces, axially spaced apart, such that each sealing surface has a greater diameter the closer that sealing ring is to the open end of the skirt, and wherein the bottle comprises a right cylindrical sidewall having an externally threaded upper end and a lower end, a bottom integrally formed with the sidewall and enclosing the lower end of the sidewall, wherein the upper end of the receptacle defines a mouth having a mouth sealing surface, wherein the method includes gripping the bottle in an automatic capping machine, gripping the cap in an automatic capping machine, rotating the cap clockwise with respect to the bottle while advancing the cap toward the bottle, engaging the external threads on the bottle to the internal threads on the cap, rotating the cap until the mouth sealing surface engages a first of the plurality of sealing surfaces, further rotating the cap until the mouth sealing surface engages a second of the plurality of sealing surfaces, wherein the second of the plurality of sealing surfaces has a smaller diameter than the first of the plurality of sealing surfaces, and sealing the container against the second of the plurality of sealing surfaces. The step of further rotating the cap may include the step of guiding at least a portion of the mouth sealing surface inwardly toward the axis of the cap. The step of further rotating the cap may include the step of deforming the mouth sealing surface into a more circular shape. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]    [0011]FIG. 1 is a cross-sectional side view of a container including a cover and receptacle in accordance with the current invention showing the flaps in an open position and as dashed lines in a closed position;  
         [0012]    [0012]FIG. 2 is an orthogonal view of the cover of FIG. 1, showing the flaps in an open position;  
         [0013]    [0013]FIG. 3 is a cross-sectional view of the container of FIG. 1 showing the angled orientation of the flap skirts;  
         [0014]    [0014]FIG. 4 is a top view of the cover of FIG. 1 with the flaps in an open position;  
         [0015]    [0015]FIG. 5 is a bottom view of the cover showing the circular sealing surfaces;  
         [0016]    [0016]FIG. 6 is a partial plan view of the sealing ring of the cap (not to scale) showing each of the sealing surfaces enlarged in exaggerated form together with the rim of the receptacle, wherein the rim of the receptacle is oval and the rim has just contacted the sealing ring during tightening;  
         [0017]    [0017]FIG. 7 is a partial cross-sectional side view of the sealing ring and receptacle rim of FIG. 6 in cross-section wherein the cutting plane for the cross section is coplanar with the longitudinal axis of the receptacle and sealing ring;  
         [0018]    [0018]FIG. 8 is a partial plan view of the sealing ring of the cap (not to scale) showing each of the sealing surfaces enlarged in exaggerated form together with the rim of the receptacle as in FIGS. 6 and 7, but after the cap has been tightened and the rim has been drawn down into the sealing ring and the ovality of the rim corrected;  
         [0019]    [0019]FIG. 9 is a partial cross-sectional side view of the sealing ring and receptacle rim of FIG. 8 wherein the cutting plane of the cross-section is coplanar with the longitudinal axis of the sealing ring and the receptacle; and+ 
         [0020]    FIGS.  10 - 12  are fragmentary cross sections of the cover and receptacle along a section line that is planar with the major elliptical axis of the warped receptacle shown in FIGS.  6 - 9  as the cap is tightened on the receptacle. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0021]    Before explaining at least one embodiment of the invention in detail it is to be understood that the invention is not limited in its application to the details of construction in the arrangement of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments or of being practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein is for the purpose of description and should not be regarded as limiting.  
         [0022]    [0022]FIG. 1 illustrates a container  10  having a receptacle  12  and a cap or cover  14 . Cover  14  includes a shaker flap  16 , called a shaker flap because it covers (when closed) shaker openings  18  disposed in planar top portion  20  of the cover. Cover  14  also includes a spooning flap  22  that similarly covers a larger spooning opening  24  also disposed in top portion  20 .  
         [0023]    The cover as best seen in FIG. 2, is in the form of a substantially cylindrical portion  26 , and top portion  20  which is coupled to an upper end of cylindrical portion  26  to enclose cylindrical portion  26 . Referring to FIG. 1, which shows a portion of the cover in cross-section with the receptacle attached, threads  28  are provided on the inner surface of cylindrical portion  26  for coupling cylindrical portion  26  to the outside of the top of receptacle  12 . As seen in FIG. 1, mating threads are disposed on an outer indented top portion of receptacle  12  to engage threads  28 . Alternatively, cylindrical portion  26  may be equipped with an inner detent or a raised ring to allow it to be snap connected to the top portion of receptacle  12 . Referring to FIG. 2, an elongate recess  19  is provided in which shaker flap  16  will fit when flap  16  is in a closed position, to provide a substantially flat upper surface of top portion  20  on which a similar container can be stacked.  
         [0024]    Referring back to FIG. 1, receptacle  12  includes a substantially planar bottom portion  30  that is adapted to engage a lip  32  of cover  14 . There is a significant advantage to this feature: since the bottom portion  30  is adapted to engage lip  32 , then a plurality of containers identical to the one pictured in FIGS. 1 and 2 can be stacked one atop the other, lip  32  serving to-orient the bottom of the next higher container and so keep the containers in proper alignment when stacked. In FIG. 1, two identical containers are shown in this stacked arrangement, the bottom of the upper container being shown as dashed line  34  engaging rim  32  when the flaps of the lower container are in a closed position (shown in FIG. 1 as dashed lines when in their closed positions). It can be seen that bottom portion  30  (and hence identical bottom portion  34 ) and top portion  20  with lip  32  are adapted to engage one another. Lip  32  is disposed at an outer edge of cover  14  to engage a recess  36  at the junction of bottom  30  and wall  38  of receptacle  12 . By disposing both lip  32  and recess  36  to engage each other near the outer periphery of the container, study has shown that the containers are more easily stacked, and when stacked tend to self-center. A portion of lip  32  is preferably disposed on shaker flap  16 , spooning flap  22  as well as on the non-hinged sides of top portion  20  as can be best seen in FIG. 4. Each of these portions is preferably disposed at an outer edge of cover  14  and have substantially the same diameter. Other designs, provide orienting means disposed more closely to the center of the container, such as by providing an indentation at or near the center of the receptacle bottom that engages with an upwardly extending protrusion located near the center of the cover on which it is stacked, are more difficult to stack accurately and also tend to tip more easily. In addition, it is harder to hold tolerances on an inner indentation than an outer indentation as shown in FIG. 1. These designs have the added disadvantage of requiring an internal recess to be formed in the center of the receptacle bottom, requiring additional machining to manufacture.  
         [0025]    Referring to FIGS. 1 and 2, a plurality of oval shaker openings  18 , preferably substantially circular as shown here, are provided to allow foodstuffs within the container to be shaken out when shaker flap  16  is opened. These openings are preferably arranged not along a straight line, but along an arc. On the underside of shaker flap  16  is an arcuate flange  40  adapted to engage and seal central shaker opening  18 . This flange extends for about 30 degrees around the periphery of its mating opening  18  when in a closed position. Flange  40  engages the inner surface of opening  18  and holds the shaker flap closed.  
         [0026]    [0026]FIG. 3 shows cover  14  in cross-section along a diametral line of the cover. The cross section is perpendicular to both the shaker flap hinge  50  and the spooning flap hinge  58 . Flange  40  does not extend perpendicularly from the underside of shaker flap  16 , but downward and outward at an angle of between 9 and 25 degrees, and more preferably of between 5 and 20 degrees with respect to the longitudinal axis of container  10 . This angular relationship is particularly beneficial in that it allows the cover, including the flaps, to be readily and integrally molded as a single monolithic piece. In addition, this angle allows flange  40  to releasably lock into central opening  18  when shaker flap  16  is closed.  
         [0027]    Shaker flap  16  also includes a skirt  46  that extends downwardly from shaker flap  16 . Skirt  46  is disposed an outer edge of shaker flap  16 . Skirt  46  is indented into the cap to provide, together with the outer surface of cylindrical portion  26  a substantially right circular cylindrical wall.  
         [0028]    Skirt  46  has an indentation  48  disposed at a central outer portion of skirt  46  and is configured to receive a finger or finger nail of the user. This allows the user to grasp shaker flap  16  and readily open container  10  by lifting upward on the indentation.  
         [0029]    Skirt  46  preferably extends around cover  14  for an arcuate length of between 60 and 120 degrees (see FIG. 4). From an outward appearance, therefore, skirt  46  would appear to form between 60 and 120 degrees of the circumference of the upper part of cover  14 . This provides a significant advantage in the design of cover  14 .  
         [0030]    Since skirt  46  is arcuate, rather than straight, it is less likely to be bent over when the cover is grasped and opened, and further distributes the grasping load more evenly around the outer edge of shaker flap  16 . This allows shaker flap  16  to be made thinner and therefore to require less plastic when manufactured.  
         [0031]    Referring to FIG. 3, when the shaker flap  16  is closed, flange  40  engages an outer portion of shaker opening  18  to thereby releasably lock shaker flap  16  to top portion  20  in a closed position. While only a single flange  40  is shown in cross section in FIG. 4, each of the other openings  18  may also have a flange (not shown) to provide additional engagement surfaces and thereby hold the shaker flap closed even better.  
         [0032]    Shaker flap  16  is coupled to top portion  20  by a flexible and integrally formed hinge  50  preferably extending the entire length of shaker flap  16 .  
         [0033]    Spooning flap  22  is coupled to top portion  20  by a flexible and integrally formed hinge  58  preferably extending the entire length of spooning flap  22 . Note that, unlike certain prior art covers with hingeable flaps, hinges  50  and  58  are disposed adjacent to a diametral line of cover  14  to allow the flaps to hinge upward and toward the middle of cover  14 . In prior art covers, the hinges were formed along an outer edge of the cover, which allowed the flaps to be opened upward and outward. This caused the flap to dangle in its open position. As a result, the flap was often in the way of the material being shaken out of the container, causing the flap to be covered with the foodstuffs or other materials inside.  
         [0034]    Spooning flap  22  covers spooning opening  24 . Spooning flap  22  has a flange  52  depending from a lower surface of spooning flap  22  that engages and locks against the inside of opening  24 . As with flange  40  on the shaker flap, Flange  52  does not extend perpendicularly from the underside of spooning flap  22 , but extends at an angle, preferably between  9  and  25  degrees outward and downward away from the underside of the spooning flap.  
         [0035]    As with flange  40  of the shaker flap, by disposing flange  52  at this angle, cover  14  can be manufactured in a single piece with spooning flap  22  formed integrally with cover  14 . Flange  52  preferably has an arcuate length of between 20 and 180 degrees (shown as 20 degrees here). Over this length, flange  52  engages the inside edge of spooning opening  24  to releasably lock spooning flap  22  to top portion  20  when spooning flap  22  is in a closed position.  
         [0036]    Spooning flap  22  also includes a skirt  60  like skirt  46  of the shaker flap. Like skirt  46 , skirt  60  extends downwardly from spooning flap  22  near an outer edge of spooning flap  22  and has an arcuate shape to define an outer substantially vertical surface of cover  14  when spooning flap  22  is in a closed position. Skirt  60  has an indentation  61  disposed at a central outer portion of skirt  60  and is configured to receive a finger or fingernail of the user. This allows the user to grasp spooning flap  22  and readily open container  10 . Skirt  60  preferably extends around the circumference of cover  14  when in the closed position for an angle pi of between 100 and 150 degrees (see FIG. 4). From an outward appearance, therefore, skirt  60  would appear to form between 100 and 150 degrees of the circumference of the upper part of cover  14 . As with skirt  46  of shaker flap  16 , since skirt  60  is arcuate, rather than straight, it has greater structural strength and it is less likely to be bent over when its flap is grasped and opened, and further distributes the grasping load more evenly around the outer edge of spooning flap  22 . This allows spooning flap  22  to be made thinner and therefore to require less plastic when manufactured. Note that the arcuate length of skirt  60  is preferably greater than the arcuate length of skirt  46 . This additional arcuate length of skirt  60  therefore provides additional strength to spooning flap  22  when the user attempts to open spooning flap  22 .  
         [0037]    A recess  62  is provided in the cylindrical portion of cover  14  to receive skirt  46  of shaker flap  16 . By providing recess  62 , skirt  46  can be set into an outer surface of cover  14  when shaker flap is closed, thereby reducing the risk that skirt  46  will be accidentally jostled and caught, shaker flap  16  opened and the contents of container  10  spilled. Similarly, a recess  64  is provided in cover  14  on the opposite side of cover  14  from recess  62  to similarly receive skirt  60  of spooning flap  22  for the same reason. The effect of skirts  46  and  60  being recessed is that the skirts form a smooth and contiguous part of the outer surface of the cylindrical portion of cover  14 .  
         [0038]    The rim  70  of receptacle  12  has an upper sealing surface  72  that abuts sealing ring  74  of the cover when the cover is screwed onto the receptacle. Sealing ring  74  has several separate and distinct sealing surfaces  76 . These surfaces are flat and extend normal to the longitudinal axis of the cap. Each sealing surface is separated from adjacent sealing surfaces by cylindrical walls  78  that are circular and parallel to the longitudinal axis of the cap. Each sealing surface defines a plane that is substantially perpendicular to the longitudinal axis of the receptacle and cover. Each of these planes intersects the longitudinal axis at a different point along its length.  
         [0039]    The wide sealing surface of the &#39;399 patent discussed briefly in the Background of the Invention is intended to accommodate rather than correct the ovality of the bottle openings. By providing a wide sealing surface, the bottle opening can be quite oval, yet will engage around its entire periphery with the sealing surface, thus providing a good, although oval seal. As we noted above, this may be effective for hand-tightened caps but not for machine-tightened caps. As torque is applied to a cap with an oval bottle opening and bottle sealing surface, the walls of the bottle at its mouth that are distorted inward toward the central axis of the bottle will collapse and be forced inward. In a similar fashion, the walls of the bottle at its mouth that are distorted outward away from the central axis of the bottle, will collapse and be forced outward. Thus, when the cap is over tightened on the bottle, the mouth of an oval bottle becomes even more oval until it finally collapses. In contrast to this, the sealing surfaces of the present invention are designed to prevent the collapse of the bottle&#39;s mouth by forcing the mouth of the bottle into a circular shape. Alternatively, the mouth of the bottle becomes ever more oval as the cap is over-torqued onto the bottle. This causes the threads adjacent to the minor axis of the oval bottle mouth to pull away from the mating threads on the caps. This disengagement, in turn, causes the cap to pop off.  
         [0040]    The stepped sealing surfaces are preferable to that of the prior art since they force warped, non-circular container mouths into a circular shape as the cap is screwed down, unlike the wide sealing surface of the &#39;399 patent.  
         [0041]    In FIGS. 6 and 7, a warped bottle with an oval rim  70  and sealing surface  72  of FIGS.  6 - 7  has just been screwed into cover  14  of FIGS. 6 and 7 by an automatic capping machine. Rim  70  just contacts the outermost sealing surface  76  of cover  14  having the largest inner and outer diameter (a slight gap is shown for convenience). In a typically manufacturing line, the automatic capping machine would rotate the cover until it reached this position, at which a certain (minimal) initial resistance to rotation would exist due to contact at points  78  and  80 .  
         [0042]    The top of the bottle is in the form of an ellipse or oval and therefore rim  70  has a major axis and a minor axis. The first parts of the bottle sealing surface to contact ring  74  are the portions of the sealing surface at the opposing ends of the major axis. The endpoints  82 ,  84  of the minor axis of the sealing surface do not even contact the cover, but are suspended in space.  
         [0043]    The tightening process does not stop with this initial contact at points  78 ,  80 , however. The torque applied by automatic capping machines has not reached its preset torque limit, and hence continues rotating, tightening the cover even more firmly to the receptacle.  
         [0044]    Since there are several independent sealing surfaces  76  on the cap, arranged in a stair step fashion, the bottle contacts the cap initially at only two small points on the rim as shown in FIGS. 6 and 7. As a result of this relatively high load on two small points of rim  70 , the capping machine&#39;s additional torque causes rim  70  to deflect and bend slightly.  
         [0045]    As the cover is further screwed down, endpoints  78 ,  80  of the major axis of sealing surface  72  are deflected inward under the increasing pressure between the cover and receptacle. Eventually, rim  70  and its sealing surface  72  assume a more circular shape. As the cover is screwed down further, the endpoints  78 ,  80  of the major axis are pushed inward toward the central axis of the cover and receptacle, and the endpoints  82 ,  84  of the minor axis are deflected outward, away from the central axis. Eventually, the rim itself is circular enough (i.e. the major axis is small enough) that the rim collapses into the next smaller diameter sealing ring  76 .  
         [0046]    This new position is shown in FIGS. 8 and 9. Note that the rim is more circular, and is completely supported on the next smaller sealing surface  76 . Since the diameter of the sealing surface  72  on rim  70  is substantially the same as the diameter of the sealing surface  76  on the cover, the cover cannot be screwed any further onto the receptacle without collapsing or bending the entire rim of the receptacle. As additional torque is applied by the capping machine to rotate the cover onto the receptacle, there is no further collapse of the rim, and the torque rises quite rapidly to the torque limit of the automatic capping machine.  
         [0047]    During this final period of rotation, the two abutting sealing surfaces rotate with respect to each other. It is this relative rotation and slippage that applies the additional torque. As a result, the friction between the surfaces is reduced to sliding friction and the rim slides with respect to sealing surface. In the device of the &#39;399 patent, there is nothing to stop the deflection from causing rim  70  to warp into an extremely oval shape. As a result, the threads often pull apart and the cover pops off.  
         [0048]    In the present invention, however, there is a mechanism to prevent the additional torque from causing more ovality. The cylindrical wall  79  between sealing surfaces  76   a  and  76   b  of the cover prevents rim  70  from deflecting outward as the final torque is applied. Rim  70  is nested inside this cylindrical surface, and therefore cannot move outward into a more out-of-round condition. If it starts to move outward, it abuts cylindrical surface  79  and stops while it is still substantially circular, and before the threads of the cover and the receptacle pull away from each other and disengage.  
         [0049]    FIGS.  10 - 12  show how a receptacle rim collapses to a smaller diameter along the major axis of the receptacle&#39;s rim. FIG. 10 shows rim  70  as it approaches sealing surface  76  of cover  14 . Point  78  is one of the end points on the major diameter of the oval-topped warped receptacle. Threads  28   a  on the receptacle engage threads  28   b  on the cover. As the cover and receptacle are rotated with respect to each other receptacle  12  moves until it is in the position shown in FIG. 11, the second of the three FIGURES. In this position, the rim just contacts the sealing surface  76  (a slight gap is shown to make the drawing easier to understand). As additional torque is applied to the cap, it rotates further until it is in the position of FIG. 12 and point  78  of rim  70  collapses to the next smaller diameter sealing surface  76 . Note that the threads  28   a  and  28   b  move slightly apart. At this stage, the entire sealing surface  72  of the rim contacts sealing surface  76  of cover  14  (a slight gap is shown to make the drawing easier to understand). The rim cannot collapse inward any further when additional torque is applied, since the minor axis has increased (as shown in FIG. 8- 9 ) so that it abuts cylindrical surface  79  between two adjacent sealing surfaces  7   b.    
         [0050]    The FIGURES show how a single receptacle with a single rim diameter is sealed against the cover. The cover is not limited to a single rim diameter, however. Since there are several sealing surfaces on the cover (four of them in the embodiments illustrated herein), each having a slightly smaller diameter, the cover can be screwed onto four different receptacles with four different rim diameters. For each of these receptacles, the operation would be the same as described above: initial contact with a first sealing surface at two points on the major diameter, collapse to the next smaller sealing surface on the cover&#39;s sealing ring, and the application of a final tightening torque while the cylindrical surface prevents the rim from deflecting outward. With four different sealing surfaces and three different cylindrical surfaces between them, this cover can accommodate at least three different receptacle rim diameters—three different receptacles. The only difference in operation is that receptacles with smaller rim diameters will rest on sealing surfaces  76  that also have smaller diameters. Receptacles with larger diameter will nest on sealing surfaces  76  with larger diameters.  
         [0051]    The system therefore accommodates a variety of receptacle mouth sizes by providing several sealing surfaces against which they can seal. It also corrects the shape of warped bottles used with automatic capping machines by forcing the bottles to collapse inward until the entire sealing surface at the rim of the bottle assumes a circular shape.  
         [0052]    Thus, it should be apparent that there has been provided in accordance with the present invention an improved container that fully satisfies the objectives and advantages set forth above. Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims.