Abstract:
A specimen collection container having an improved sealing mechanism that provides enhanced sealing properties during transport, storage, and handling. The specimen collection container comprises a cup, cap and improved sealing mechanism. The sealing mechanism forms multiple seals between the cup and cap. In a preferred embodiment, the sealing mechanism forms primary, secondary and tertiary seals between the cap the cup. The primary and secondary seals are preferably formed between the cap and the interior surface of the cup. The tertiary seal is preferably formed between the cap and the distal edge of the cup. The first, second and third seals are sequentially formed as the cap is rotated from a first radial position at which the threads first engage each other to a second radial location at which the cap is fully closed. Each of the three seals on its own is capable of sealing the container and preventing a fluid specimen from leaking from the cup if the seal is maintained. The primary and secondary seals are constructed and arranged to seal the cup after the cup and cap are threadingly engaged independent of the amount of torque applied to the cap.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to provisional patent application No. 61/751,868, filed Jan. 12, 2013, entitled Specimen Collection Container System, and provisional application No. 61/751,937 filed Jan. 13, 2013, entitled Specimen Collection Container System, both of which are incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    This invention relates to a specimen collection container having an improved sealing mechanism. More particularly, the invention relates to a specimen collection container having an improved sealing mechanism that provides enhanced sealing properties during transport, storage, and handling. 
       BACKGROUND OF THE INVENTION 
       [0003]    It is well known that specimen containers are used to collect and transport medical samples from a collection site to various locations for analysis. The prior art teaches a wide variety of specimen containers, which are often, but not always, made from deformable plastic. Frequently, these containers are “pre-filled” with preservatives or other chemicals that are required to preserve the sample and/or initiate the analysis process. 
         [0004]    In many cases, after the container has been closed and sealed, it is subjected to significant environmental pressure changes either during shipping or handling. For example, the containers are often shipped by air freight from the manufacturer to the collection site, and/or from the collection site to a laboratory. Since the cargo area of an airplane is usually not pressured, the container is subjected to significant pressure changes during transport. Additionally, some test facilities use internal, pneumatic, tubular transportation systems to convey the containers from station to station within a test facility. These pneumatic transportation systems also subject the container to significant pressure changes. 
         [0005]    When subjected to significant pressure changes, prior art specimen containers are known to leak for a variety of reasons. For example, enhanced pressure may cause the cap to loosen, may cause distortion of a cap seal, or may cause distortion of the cap itself. Whatever the cause, leakage is unacceptable, especially when the specimen within the container is toxic or infectious. Therefore, it would be desirable to provide a specimen container having a seal mechanism that provides improved sealing under significant pressure differential during shipping or transport. 
         [0006]    In order to provide an improved seal on the specimen container, prior art devices may provide a more snug tolerance between the cap and the container, or a design that requires increased torque to fully close the lid. Some patients, especially elderly patients, may not have the hand strength to properly close the lids of such containers. Therefore, it would be desirable to provide a container having a seal mechanism that does not require excessive torque to completely close and seal the lid to prevent leaking. 
         [0007]    On most prior art collection containers, the cap must be torqued a predetermined amount, i.e., twisted past a certain angular orientation, in order to properly close and fully seal the cap to the cup. Often the patient is unsure if he/she has torque/tightened the cap sufficiently to fully engage the sealing mechanism. If the cap us under torqued, the cup will not be fully sealed. If the cap is over torqued, the threads may be stripped and/or the sealing mechanism may be damaged. Therefore, it would be desirable to provide a specimen collection container having a mechanism that provides a detectible indicator when the cap has been sufficiently torqued to properly seal the lid to the cup. 
       SUMMARY OF THE INVENTION 
       [0008]    The present invention provides a specimen collection container having an improved sealing mechanism that provides enhanced sealing properties during transport, storage, and handling. In one preferred embodiment, the specimen collection container comprises a cup, cap and improved sealing mechanism. 
         [0009]    The cup has a closed bottom end and an open upper end, a bottom surface at the closed end, sidewalls extending from the periphery of the bottom surface and terminating at a distal upper edge, and threads formed on the upper, outer surface of the side walls. The cap has a closed top end and an open bottom end, a top surface at the closed upper end, sidewalls extending from the periphery of the top surface and terminating at a distal lower edge, and threads formed on the interior surface of the side walls that compliment and engage the threads on the cup to open and close the cap on the cup. 
         [0010]    The sealing mechanism forms multiple seals between the cup and cap. In a preferred embodiment, the sealing mechanism forms primary, secondary and tertiary seals between the cap the cup. The primary and secondary seals are preferably formed between the cap and the interior surface of the cup. The tertiary seal is preferably formed between the cap and the distal edge of the cup. The first, second and third seals are sequentially formed as the cap is rotated from a first radial position at which the threads first engage each other to a second radial location at which the cap is fully closed. Each of the three seals on its own is capable of sealing the container and preventing a fluid specimen from leaking from the cup if the seal is maintained. 
         [0011]    In a preferred embodiment, the primary and secondary seals comprise a plug that extends from the cap and engages the interior surface of the cup at two separate locations. The plug is integrally formed with and extends downwardly from the top wall of the cap, and has an inner plug surface, an outer plug surface and a distal end surface. The inner plug surface has a flat, regular geometry and extends axially at an obtuse angle relative to the plane of the central portion of the cap. The outer plug surface has an irregular geometry and also extends at an obtuse angle relative to the plane of the central portion of the cap. In one preferred embodiment, the primary seal and a secondary seal comprise protrusions on the outer plug surface, which contact the inner surface of the upper portion of the sidewall of the cup. 
         [0012]    The primary and secondary seals are constructed and arranged to seal the cup after the cup and cap are threadingly engaged independent of the amount of torque applied to the cap. Therefore, the cup will be sealed even if sufficient torque has not been applied to close the cap fully and to engage the tertiary seal. 
         [0013]    The tertiary seal preferably comprises an annular seat in the cap having a shape that compliments the shape as the distal edge of cup. The annular seat is preferably integrally formed on the cap intermediate the annular plug and support bead. 
         [0014]    The collection container also preferably includes a support mechanism on the cap that engages the outer surface of the cup at support locations opposed to at least one of the seals. In a preferred embodiment the support mechanism supports the cup at locations generally opposed to the primary and secondary seals. 
         [0015]    The cap includes reinforcing means on the top surface and the sidewall. The cap reinforcing means preferably comprises a plurality of radially-projecting strengthening ribs on the interior surface of the central, circular portion, and a plurality of equally-spaced, radially-projecting gussets on the outer surface. 
         [0016]    The cup may also include reinforcing means on the sidewall. The cup reinforcing means preferably comprises a strengthening ring that extends around the periphery of the outer surface. The cup reinforcing means may also comprise a plurality of radially-extending strengthening ribs on the bottom surface. 
         [0017]    The specimen container may also include an indicator that informs the user whether or not the cap is fully closed on the cup. In one embodiment, the indicator comprises a detent mechanism that creates at least one audible click sound when the cap is fully closed. In another embodiment, the indicator is visual and includes an arrow on the cap and a series of bar on the cup, which align when the cap is fully closed. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]      FIG. 1  is an exterior, perspective view of the top cap of the collection container in accordance with an embodiment of the invention; 
           [0019]      FIG. 2  is a top plan view of the cap shown in  FIG. 1 ; 
           [0020]      FIG. 3  is a side elevation of the cap shown in  FIG. 1 ; 
           [0021]      FIG. 4  is a  FIG. 1  is an interior, perspective view of the cap shown in  FIG. 1 ; 
           [0022]      FIG. 5  is a bottom plan view of the cap shown in  FIG. 1 ; 
           [0023]      FIG. 6  is a perspective view of the cup of the collection container in accordance with an embodiment of the invention; 
           [0024]      FIG. 7  is a top plan view of the cup shown in  FIG. 6 ; 
           [0025]      FIG. 8  is a side elevation of the cup shown in  FIG. 7 ; 
           [0026]      FIG. 9  is a cross-section of the collection container showing initial engagement of the cap and cup; 
           [0027]      FIG. 10  is an enlarged section of the sealing mechanism of the collection container shown in  FIG. 9 ; 
           [0028]      FIG. 11  is a cross-section of the collection container showing intermediate (partially-closed) engagement of the cap and cup  14 ; 
           [0029]      FIG. 12  is an enlarged section of the sealing mechanism of the collection container shown in  FIG. 11 ; 
           [0030]      FIG. 13  is a cross-section of the collection container showing final (fully-closed) engagement of the cap and cup; 
           [0031]      FIG. 14  is an enlarged section of the sealing mechanism of the collection container shown in  FIG. 13 ; 
           [0032]      FIG. 15  is a perspective view of a cup in accordance with another embodiment of the invention; 
           [0033]      FIG. 16  is a side elevation of the cup shown in  FIG. 15 ; 
           [0034]      FIG. 17  is a top plan view of the cup shown in  FIG. 15 ; 
           [0035]      FIG. 18  is front elevation of the cup shown in  FIG. 15 ; 
           [0036]      FIG. 19  is a bottom plan view of the cup shown in  FIG. 15 ; and 
           [0037]      FIGS. 20-25  illustrate additional features in accordance with further embodiments of the invention. 
       
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0038]    For the purpose of illustration, there is shown in the accompanying drawings several embodiments of the invention. However, it should be understood by those of ordinary skill in the art that the invention is not limited to the precise arrangements and instrumentalities shown therein and described below. To more clearly illustrate the invention, the drawings are not necessarily to scale. 
         [0039]    A specimen collection container in accordance with one embodiment of the invention is shown in  FIGS. 1-14  and is designated generally by reference numeral  10 . An additional embodiment of the invention is illustrated in  FIGS. 15-18 . Although the invention is described below as a specimen collection container, it should be appreciated by those of ordinary skill in the art that the invention is not limited to use in connection with collection and containment of patient specimens; rather, the invention may include use of the container for collecting, storing and/or transporting fluids of any type. 
         [0040]    The container  10  generally comprises a cap and a collection cup, designated generally by reference numerals  12 ,  14 , respectively. The cap  12  and collection cup  14  have cooperatively engaging threads,  22 ,  34 , respectively. The cap  12  includes a sealing mechanism, designated generally by reference numeral  16 , which engages and seals the open end of the collection cup  14 . 
         [0041]    The cap  12  and cup  14  have cylindrical shapes with one circular closed end. As used hereinafter, the term “axially-extending” refers to the direction parallel to the central axis of the cylinder, and the term “radially-extending” refers to the direction parallel to a radius of the circular closed end of the cylinder. 
         [0042]    In an embodiment of the invention, the cap  12  has a central, top wall  18 , an annular side wall  20  extending generally transverse to the plane of the top wall  18 , and protruding threads  22  on the inner surface of the side wall  20 . The side wall  20  has a cylindrical shape, extends from the periphery of the top wall  18 , and terminates at a distal edge  20   c . As best seen in  FIGS. 1 and 2 , the top wall  18  has a raised, annular portion  18   a  on the periphery, a circular central portion  18   b , and a concave (relative to the exterior of the cap) depression  18   c  in the center of the central portion  18   b . The three portions  18   a - c  form the continuous surface of the top wall  18  of the cap  12 . 
         [0043]    Referring to  FIGS. 1 and 3 , the exterior of the side wall  20  has a textured or knurled outer surface so that the cap can be more easily gripped during rotation. In the embodiment shown in  FIGS. 1 and 3 , the exterior surface includes a plurality of equally-spaced, radially-projecting ridges or gussets  24 . The ridges  24  are preferably integrally formed on the exterior surface and may have any shape that makes the cap easier to grip during turning. The ridges  24  also stiffen the side wall  20  to prevent distortion during gripping and during significant pressure changes. 
         [0044]    In the embodiment shown in  FIGS. 1-14 , the ridges  24  are equally spaced around the entire circumference of the side wall  20 . However, the ridges  24  may be provided on less than the entire circumference of the wall  20 . In an alternative embodiment, the ridges  24  are provided around the cap circumference at select locations where a gripping force maximizes the effectiveness of the unique features of the collection container  10 , described below. 
         [0045]    In the embodiment shown in  FIGS. 1-14 , the ridges  24  extend axially only along a partial, upper portion  20   a  (relative to the top surface) of the side annular wall  20 , thereby defining a smooth, lower (relative to the top surface) band  20   b . In this embodiment, the ridges are located and opposed axial locations to the sealing mechanism  16  and stiffen the portion of the wall to which the inner sealing mechanism is attached. However, in other embodiments, the ridges  24  may extend along the entire axial length of the side wall  20 . 
         [0046]    As best seen in  FIGS. 4-5 , the interior surface of the central, circular portion  18   b  includes a plurality of radially-projecting strengthening ribs  26 , which are integrally formed in the central top wall  18  and extend axially along. In the embodiment shown in  FIGS. 1-14 , the ribs  26  extend from the outer periphery of the central portion  18   b  to the central depression  18   c . The ribs  26  provide increased rigidity to the large, flat central portion of the cap, which might otherwise deflect or deform under significant pressure changes. In the embodiment shown in  FIGS. 1-14 , the ribs  26  extend only partially into the central depression  18   c  since the shape of the central depression provides increased rigidity compared to a flat surface. However, in another embodiment, the ribs may extend fully to the center of the depression  18   c  to further increase the rigidity of the central top wall  18 . The shape and construction of the top wall  18  add rigidity to the top wall  18 , which helps prevent distortion of the cap under significant pressure change. 
         [0047]    Referring to  FIGS. 4 and 5 , the inner surface of the side wall  20  includes protruding threads  22  that cooperate with threads  34  on the outer surface of the cup  14 , described below. The threads  22  initiate at an intermediate point along the axial length of the side wall  20  and terminate at a second intermediate point below the top wall  18 . The inner annular surface above and below the threaded portion has a generally smooth interior. 
         [0048]    In the embodiment shown in  FIGS. 1-14 , the cup  14  of the collection container  10  has a central, bottom wall  30 , an annular side wall  32  extending generally transverse to the plane of the bottom wall  30 , and protruding threads  34  on the exterior surface of the side wall  32 . The side wall  32  extends from the periphery of the bottom top wall  30  and terminates at a distal edge  20   c.    
         [0049]    As best seen in  FIGS. 7 and 8 , the central bottom wall  32  has a circular, flat construction and the side wall  32  has a cylindrical shape. The outer surface of the side wall  32  has an upper (relative to the bottom wall  30 ) section  32   a , intermediate section  32   b , and a lower section  32   c . The three portions  32   a - c  form the continuous outer surface of the side wall  32  of the cup  14 . The inner surface of the side wall  32  is smooth along its entire axial length. The thickness of the side wall  32  is generally uniform along it axial length. 
         [0050]    In one embodiment, the upper section  32   a  has a smooth outer surface and an axial length of about 3.4 millimeters. The upper section  32   a  engages the seal mechanism, described below, of the cap  12 . 
         [0051]    In one embodiment, the intermediate section  32   b  has protruding threads  34  and an axial length of about 9.3 millimeters. The threads  34  cooperatively engage the threads  22  on the cap  12 . 
         [0052]    The lower section  32   c  has a smooth outer surface and an axial length of about 29.2 millimeters, although the length may vary depending on the size of the container  10 . A strengthening ring  38  extends around the periphery of the cup  14  and generally demarcates the boundary between the intermediate section  32   b  and the lower section  32   c . The ring  38  prevents distortion of the cup  14  under significant pressure changes or during installation of the cap. 
         [0053]    The sealing mechanism  16  in accordance with an embodiment of the invention is best described with reference to  FIGS. 9-14 . The sealing mechanism  16  is incorporated in the cap  12  and engages the upper section  32   a  and distal edge of the cup  14 . The sealing mechanism  16  generally comprises an annular plug  42 , an annular seat  44 , and an annular support bead  46 . In general, the annular plug  42  forms primary and secondary plug seals  52   a ,  52   b  with the interior surface of the cup  14 . The annular seat  44  has a shape that compliments and forms a tertiary seal  52   c  with the distal edge  32   d  of the cup  14 . The support bead  46  has primary and secondary supports  46   a ,  46   b  on the inner surface of the upper portion of the cup  14  at locations generally opposed to the locations of the primary and secondary seals  52   a ,  52   b.    
         [0054]    As best seen in  FIGS. 5 ,  10 ,  12  and  14 , the annular plug  42  is integrally formed with and extends axially downwardly (relative to the top wall  18 ) from the top wall  18 . The annular plug  42  includes an inner plug surface  50 , an outer plug surface  52  and a distal end surface  54 . The inner plug surface  50  has a flat, regular geometry and extends axially at an obtuse angle relative the plane of the central portion  18   b  of the cap  12 . 
         [0055]    The outer plug surface  52  has an irregular geometry and also extends generally axially at an obtuse angle relative to the plane of the central portion  18   b  of the cap  12 . The outer plug surface  52  has a primary seal  52   a  and secondary seal  52   b , which contact the inner surface of the upper portion  32   a  of the sidewall of the cup  14 . In the embodiment shown in  FIGS. 1-14 , the primary and secondary seals  52   a ,  52   b  comprise protrusions on the outer plug surface  52 . However, in alternative embodiments, the primary and secondary seals  52   a ,  52   b  may comprise separate seal elements formed in or fixed to the outer plug surface  52 . The distal end surface  54  is generally flat with rounded corners and extends between the inner and outer plug surfaces. 
         [0056]    The annular seat  44  is formed intermediate the annular plug  42  and support bead  46 . Referring to  FIGS. 10 ,  12  and  14 , the seat  44  is generally flat and extends around the periphery of the cap  12 . In the embodiment shown in  FIGS. 1-14 , the seat  44  is integrally formed on the top wall  18 . However, in alternative embodiments, the seat  44  may comprise one or more separate seat elements formed in or fixed to the top wall  18  of the cap  12 . 
         [0057]    The annular support bead  46  has an irregular geometry and also extends generally axially relative to the plane of the central portion  18   b  of the cap  12 . In the embodiment shown in  FIGS. 1-14 , the support bead  46  is integrally formed on the upper, interior surface of the side wall  20  of the cap  12 . However, in alternative embodiments, the support bead  46  may comprise one or more separate bead elements formed in or fixed to the side wall  20  of the cap  12 . 
         [0058]    The annular support bead  46  has a primary support  46   a  and secondary support  46   b , which contact the outer surface of the cup  14 . In the embodiment shown in  FIGS. 1-14 , the primary and secondary supports  46   a ,  46   b  comprise protrusions on the support bead  46 . However, in alternative embodiments, the primary and secondary supports  46   a ,  46   b  may comprise separate support elements formed in or fixed to the side wall  20  of the cap  12 . 
         [0059]    The construction and operation of the plurality of seals in the seal mechanism  16  is illustrated in  FIGS. 10 ,  12 , and  14 .  FIG. 10  illustrates the container  10  after the cap has been installed on the cup  14  and partially tightened by rotating the cap approximately ¼ of a revolution. In this first position, the primary seal  52   a  of the plug  46  first engages the inner surface of the cup  14 . In this first position, the container  10  is sealed by the primary seal  52   a.    
         [0060]      FIG. 12  illustrates the container  10  after the cap  12  has been more fully tightened by rotating the cap  12  approximately an additional ¼ revolution. In this second position, the secondary seal  52   b  also engages the inner surface of the cup  14 . The primary seal  52   a  remains in contact with the inner surface of the cup  14  but has moved axially downwardly into the cup  14 . In the second position, the primary support  46   a  also engages the outer surface of the cup  14 . In this second position, the container is sealed with both the primary and secondary seals  52   a ,  52   b.    
         [0061]      FIG. 14  illustrates the container after the cap  12  has been fully tightened by rotating the cap  12  by approximately a final ¼ revolution. In this third position, the tertiary seal  52   c  engages the distal edge  32   d  of the cup  14 . The primary seal  52   a  and secondary seal  52   b  remain in contact with the inner surface of the cup  14  but have moved axially downwardly into the cup  14 . The primary support  46   a  also remains in contact with the outer surface of the cup  14  but has moved axially downwardly. In the fully closed position, the second support  46   b  also engages the outer surface of the cup  14 . As best seen in  FIG. 12 , the primary and secondary supports  46   a ,  46   b  engage the outer surface at about the same axial location as the primary and secondary seals  52   a ,  52   b , respectively, but on opposite sides (inner vs. outer) of the upper portion  32   a  of side wall  32 . 
         [0062]    In the preferred embodiment, the cap  12  and cup  14  are preferably made from a deformable thermoplastic material such as polypropylene using known injection molding techniques. The seals and supports of the cap rely on the deformability and flexibility of the material to function properly. In  FIGS. 12 and 14 , an overlap or interference between the upper portion  32   a  of the side wall  32 , the annular plug  42  and annular support bead  46  are indicated by reference letter “I” at multiple locations. At these locations, the side wall  32  does not compress or deform. Rather, the various components of the sealing mechanism deform. However, in  FIGS. 12 and 14  the original configuration of the sealing mechanism components are shown in their original, uncompressed/deformed shape to better illustrate the locations of the several seals and supports. 
         [0063]    With respect to identifying the seals, the terms primary, secondary and tertiary are not necessarily used to denote importance or sealing capacity. Instead, the terms primary, secondary, and tertiary indicate the order in which the seals engage the side wall  32  of the cup  14  during closing of the cap  12 . 
         [0064]    The sealing mechanism  16  of the present invention has several advantages over prior art container seals. The integrity of the tertiary seal  52   c  of applicant&#39;s sealing mechanism  16  relies on a sufficient amount of torque being applied to the cap to press the distal edge  32   d  of the cup  14  into the annular seat  44  with sufficient force to form a seal. In contrast, the primary and secondary seal  52   a ,  52   b  of the sealing mechanism  16  do not rely on significant patient torque to form the seal. The primary and secondary seals  52   a ,  52   b  are formed when the plug  42  enters the opening of the cup  14 . Only a very small amount of torque is required to rotate the cap to a position wherein the primary and secondary seals  52   a ,  52   b  engage the inner surface of the cup  14 . Therefore, even if the patient does not provide sufficient torque to fully close the cap and engage the tertiary seal  52   c , the container remains sealed by the primary and secondary seals  52   a ,  52   b.    
         [0065]    In the fully-closed position, the container  14  has three separate seals and two separate seal supports. The cap  12  also has strengthening ribs  38  in the central top wall  18 . The supports and ribs prevent the cup  14  from deforming under significant pressure changes. Since the cup  14  does not deform, the upper portion  32   a  of the cup  14  does not disengage from any of the seals. 
         [0066]    In a preferred embodiment, the container  10  includes a detent mechanism that makes an audible “click” sound when the cap has been tightened sufficiently to engage all three seals of the sealing mechanism  16 . In the embodiment shown in  FIGS. 1-14 , two tabs  28  extend radially-inwardly from the inner surface of the cap proximate the distal edge  20   c . In the embodiment shown in  FIGS. 1-14 , the tabs  28  are diametrically opposed and integrally formed with the annular wall. Two detents  40  extend radially from the intermediate section  32   b  of the cup  14  below the threads  34 . In this embodiment, the detents  40  comprise integrally-formed, flexible protrusions that are axially positioned to engage the tabs  28  when the cap is tightened fully enough to engage each of the three seals. 
         [0067]    In another embodiment, shown in  FIGS. 20-25 , the detent mechanism comprises two pair of tabs, which extend radially-inwardly from the inner surface of the cap proximate the distal edge  20   c . In this embodiment, the tabs have the same construction as described above with respect to tabs  28 ; however, due to this dual construction, the tabs makes an audible “double-click” sound when the cap has been tightened sufficiently to engage all three seals of the sealing mechanism  16 . 
         [0068]    A specimen collection cup  114  container in accordance with another embodiment of the invention is shown in  FIGS. 15-19 . The cup  114  has a construction similar to the construction of the cup  14  described above. In the embodiment shown in  FIGS. 15-19 , the cup  114  has a central, bottom wall  130 , an annular side wall  132  extending generally transverse to the plane of the bottom wall  130 , and protruding threads  134  on the exterior surface of the side wall  132 . The side wall  132  extends from the periphery of the bottom wall  130  and terminates at a distal edge  120 . 
         [0069]    As best seen in  FIGS. 17 and 19 , the cup has a circular bottom wall  130  and the side wall  132  has a cylindrical shape. The outer surface of the side wall  132  has an upper (relative to the bottom wall  130 ) section  132   a , intermediate section  132   b , and a lower section  132   c . The three portions  132   a - c  form the continuous surface of the side wall  132  of the cup  114 . The inner surface of the side wall  132  is smooth along its entire axial length. The thickness of the side wall  132  is generally uniform along it axial length. 
         [0070]    The upper section  132   a  has a smooth outer surface and an axial length of about 2.5 millimeters. The upper section  132   a  is constructed to engage the seal mechanism  16  of the cap  12  described above. 
         [0071]    The intermediate section  132   b  has protruding threads  34  and an axial length of about 10 millimeters. The threads  134  are constructed to cooperatively engage the threads  22  on the cap  12  described above. 
         [0072]    The lower section  132   c  has a smooth outer surface and an axial length of about 35 millimeters, although the length may vary depending on the size of the container  10 . A strengthening ring  138  extends around the periphery of the cup  114  and generally demarcates the boundary between the intermediate section  132   b  and the lower section  132   c . The ring  138  prevents distortion of the cup  114  under significant pressure changes or during installation of the cap. 
         [0073]    In this embodiment, the ring  138  also defines a shoulder at which the diameter of the cup changes between the intermediate section  132   b  and the lower section  132   c . In this embodiment, the diameter of the lower section  132   c  is slightly smaller than the diameter of the intermediate section  132   b  and the upper section  132   a . Preferably, the lower section has a slightly tapered diameter to allow the cups to be stacked on top of each other. 
         [0074]    In the embodiment show in  FIGS. 15-19 , the cup and cap are larger than prior art specimen containers. For example, in the embodiment shown in  FIGS. 15-19 , the cup  114  has volumetric capacity of about 50 ml. Therefore, the cup  114  includes additional stiffening features, compared to the cup  14  described above, to help prevent distortion of the cup  114  during significant pressure changes. Because of the increased size of the cup, the bottom wall of the cup  114  includes a plurality of radially-projecting strengthening ribs  120 , which are integrally formed in the bottom wall  130 , and a central depression  131 . In the embodiment shown in  FIGS. 15-19 , the ribs  120  extend from the outer periphery of the bottom wall to a central depression. The ribs  121  provide increased rigidity to the large flat bottom wall of the cup  114 , which might otherwise deflect or deform under significant pressure changes. In the embodiment shown in  FIGS. 15-19 , the ribs  120  extend only partially into the central depression  131  since the shape of the central depression  131  provides increased rigidity compared to a flat surface. However, in another embodiment, the ribs may extend fully to the center of the depression  131  to further increase the rigidity of the bottom wall. 
         [0075]    The cup  114  also includes a plurality of gussets  117  on the threaded, interior, intermediate portion  132   b  of the side wall  132 . As best seen in  FIG. 15 , the gussets  117  are integrally formed on and connect both the shoulder and the inner surface of the intermediate portion  132   b . The gussets add rigidity to the cup  114 , which has a diameter much larger than prior art containers. 
         [0076]    Referring to  FIGS. 20-26 , the specimen collection container of this embodiment include a visual indicator that that informs the user whether or not the cap is fully closed on the cup. In this embodiment, the indicator is similar to the indicator disclosed in U.S. patent application Ser. No. 10/998,165 entitled Biological Specimen Collection Container, filed Jun. 23, 2005, incorporated herein by reference. The indicator comprises a arrow on the outer annular surface of the cap and a plurality of individual bars of increasing length on the outer surface of the cup. When the arrow on the cap is positioned over any one of the bars, the cap has been torqued sufficiently to fully close the cap and engage all three seals. Preferably, the user torques the cap until the arrow aligns with the longest bar on the cup. 
         [0077]    While the principles of the invention have been described above in connection with specific embodiments, it is to be clearly understood that this description is made only by way of example and not as a limitation on the scope of the invention.