Abstract:
The present invention provides a method of collecting a liquid sample using a leak proof, air tight plastic container device. The method comprises placing the sample in the container device, the device comprised of a container, a lid, a lid groove containing a gasket therein which covers and tightens over the rim of the container, a lid flange, and a thin hook in the container containing a second gasket compressed by the lid flange when the lid is closed over the container; and sealing the sample in the container device by engaging the internal screw threads of the lid with the external screw threads of the container and rotating the lid until resistance to rotation is encountered. The method further comprises transporting the sample to a site for analysis, whereby no leakage of the liquid sample and no air seepage into or out of the container occur during transport.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a divisional of application Ser. No. 14/732,709, filed Jun. 6, 2015, which is incorporated herein by reference in its entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to medical laboratory equipment and, in particular, to an improved, leak proof, air tight, cost-effective liquid specimen plastic container. 
       BACKGROUND OF THE INVENTION 
       [0003]    Body fluids, such as urine, routinely are taken from individuals by medical personnel for laboratory analysis. The typical specimen is collected at one location, such as a medical doctor&#39;s office or hospital, and then transported to a clinical laboratory site where the specimen is subjected to analysis. The specimen usually is collected in a plastic container that is shipped in the same container. The laboratory site may be quite distant from the collection site and the specimen container often is forwarded by mail, including air mail. To maintain the integrity of the sample it is necessary that the specimen container be leak proof and air tight to prevent fluid loss and possible air contamination during handling while in transport, especially when subjected to reduced atmospheric pressure that may occur during air transport. 
         [0004]    Conventional plastic specimen containers with removable lids for medical purposes are not completely leak proof and air tight. Plastic specimen containers which purport to be leak proof and/or air tight usually include intricate sealant design features which can be costly to manufacture, or require sealant materials placed over external areas of the container where the container and its lid engage, without which complete fluid retention and air-tightness in the container cannot be ensured. Complete sealant properties are especially necessary when the plastic container is stored for an extended period of time, where it is likely that the plastic container will undergo slight deformations in shape due to temperature and pressure changes, resulting in fluid leakage as well as slow air seepage into and out of the container. 
         [0005]    A need exists, therefore, for an improved plastic container for collection and transport of medical specimens which is completely leak proof and air tight for extended periods of time and under varying temperatures and atmospheric pressure without the need for costly manufacturing sealant design features or additional external sealant materials. 
       SUMMARY 
       [0006]    The present invention fulfills this need by providing an improved, cost-effective, plastic medical specimen container device that is completely leak proof and air tight for extended periods of time and environmental conditions, such as mechanical stressors and varying temperature and atmospheric pressure. 
         [0007]    In particular, the present invention provides a leak proof, air tight, plastic specimen container device comprising a container and a lid. The container is comprised of a circumferential sidewall having an inner surface and an outer surface, an upper rim of the side wall, and a bottom. Projecting into the interior of the container from the inner surface of the circumferential side wall located downwardly from the upper rim is a hook. The hook contains a gasket therein. A plurality of external screw threads projects downwardly from the upper rim on the outer surface of the circumferential side wall. The lid comprises an outer side and an inner side and a peripheral edge. A plurality of indentations project downwardly from the outer side of the peripheral edge, and a plurality of internal screw threads project downwardly from the peripheral edge of the inner side. Located on the inner side of the lid adjacent to the peripheral edge is an annular groove having a lid gasket therein. Adjacent to the annular groove is an annular flange on the inner side adjacent to the annular groove. 
         [0008]    The lid of the container device is configured to rotatably screw on to the outside of the container by engagement of the internal screw threads of the lid with the external screw threads of the container. The lid flange is configured to insert into the hook when the lid is rotatably screwed on to the container. When the lid is closed on the container, the container gasket is compressed by the lid flange and the lid gasket is compressed by the upper rim of the container. The compression of the lid gasket and the container gasket completely seals the lid onto the container to prevent any leakage of the liquid sample from the interior of the container and any air seepage into or out of the interior of the container. 
         [0009]    The volume capacity of the liquid contents of the container device may be, without limitation, 500 ml down to 40 ml, with all sizes in-between decreased from 500 ml in 20 ml increments. 
         [0010]    The present invention also provides a method of collecting a liquid sample comprising placing the liquid sample in the leak proof, air tight, plastic specimen container device described above, and sealing the liquid sample in the container by engaging the internal screw threads of the lid with the external screw threads of the container, and rotating the lid in a screw-type fashion until resistance to the rotation is encountered. The method further comprises ensuring leak proof, air tight transport of the liquid sample during transport from the site of specimen collection to a different site for laboratory analysis. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    A fuller understanding of the invention can be gained from the following description when read in conjunction with the accompanying figures, where like reference numerals refer to identical or functionally similar elements throughout the separate views, which illustrate some, but not the only and exclusive, examples of embodiments of the invention and, as such, the figures disclosed herein are to be considered illustrative rather than limiting. In the drawings: 
           [0012]      FIG. 1  is a front view of the plastic specimen container device shown with the lid in a closed position on the container in accordance with an embodiment of the invention; 
           [0013]      FIG. 2  is a perspective sectional view taken along line  2 - 2  of  FIG. 1 ; 
           [0014]      FIG. 3  is an enlarged view of section  3  encircled in  FIG. 2 ; 
           [0015]      FIG. 4  is a front view of the plastic specimen container device shown with the lid in a partially opened position on the container in accordance with an embodiment of the invention; 
           [0016]      FIG. 5  is a perspective sectional view taken along line  5 - 5  of  FIG. 4 ; 
           [0017]      FIG. 6  is an enlarged view of section  6  encircled in  FIG. 5 ; 
           [0018]      FIG. 7  is a top view of the inner surface of the lid of the plastic specimen container device in accordance with an embodiment of the invention; 
           [0019]      FIG. 8  is a sectional view taken along line  8 - 8  of  FIG. 7 ; and 
           [0020]      FIG. 9  is an enlarged view of section  9  encircled in  FIG. 8 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0021]    Referring now to the drawings, the invention comprises an improved, leak proof, air tight, cost-effective, plastic container device  10  for collecting and transporting liquid specimens for laboratory analysis. 
         [0022]    As shown in  FIGS. 1-6 , the leak proof, air tight, plastic container device  10  includes a generally circular container  12  and a generally circular lid  14  that closes over and seals the container  12  (closed container shown in  FIGS. 1-3 ; open container shown in  FIGS. 4-6 ). The container  12  comprises an interior for holding a liquid sample, the interior bounded by a circumferential side wall  44 , which has an outer surface  16 , an inner surface  18 , and a base  30 . As best seen in  FIGS. 3 and 5 , the upper end of the side wall  44  terminates in an upper rim or edge  20  that is continuous with the outer surface  16  and the inner surface  18  of the container  12 . Projecting downwardly from the upper rim  20  on the outer surface  16  of the container  12  are a plurality of annular external screw threads  22  oriented generally perpendicular to the side wall  44  of the container  12  (best seen in  FIGS. 4 and 6 ). Continuous with the inner surface  18  of the upper rim  20  is a hook  34  located downwardly from the upper rim  20  for receiving a gasket therein (best seen in  FIGS. 3 and 6 ). In an embodiment, the hook  34  is generally L-shaped hook. 
         [0023]    As shown in  FIGS. 2 and 5 , the lid  14  includes an outer side  24  and an inner side  26 . The periphery of the lid  14  projects downwardly from the outer side  24  of the lid  14  to form a shoulder which contains a plurality of indentations  28  oriented generally perpendicular to the outer side  24  of the lid  14 . In use, the plurality of indentations  28  facilitates gripping the lid  14  when opening and closing the container  12 . As shown in  FIG. 8 , adjacent to the periphery of the lid  14  on the inner side  26  is an annular groove  38  which protrudes slightly on the outer surface  24  of the lid  14  to form an annular bulge  46  (best seen in  FIGS. 3, 6 and 9 ). As shown in  FIG. 9 , the groove  38  is a configured to receive a lid gasket  40  therein. Adjacent to the annular groove  38  is an annular flange  42 . When the lid  14  is closed over the container  12 , the lid gasket  40  in the annular groove  38  sits atop, completely covers, and is compressed upon the upper rim  20  of the container  12  to form a tight seal. The annular flange  42  inserts into the hook  34  in the container  12  which contains the container gasket  36  (best seen in  FIGS. 3 and 6 ). Projecting downwardly from the periphery of the lid  14  on the inner side  26  are a plurality of annular internal screw threads  32  oriented generally perpendicular to the inner side  26  and the outer side  24  of the lid  14  (best seen in  FIGS. 6, 8 and 9 ). The internal screw threads  32  of the lid  14  are configured to be complementary to and engage the external screw threads  22  of the container  12  so that the lid  14  rotatably closes on to the container  12  when moved in a direction parallel to the engaged screw threads. When resistance is encountered to rotation of the lid  14  on to the container  14 , the container is effectively leak proof and air tight with the contents of the container  14  being completely sealed therein. 
         [0024]    In an embodiment, the plastic container device  10  of the invention has a liquid capacity of 120 ml having the following dimensions: diameter of the lid  14  ranges from about 4.0 cm to about 8.0 cm; length of the lid screw threads  32  and the container screw threads  22  range from about 1.0 cm to about 2.0 cm; length of the container  12  from the bottom  30  of the container  12  to the bottom of the container screw threads  22  ranges from about 5.0 cm to about 8.0 cm; thickness of the container  12  from the inner side wall  16  to the outer side wall  18  ranges from about 0.5 mm to about 2.0 mm; length of the hook  34  from the upper rim  20  of the container  12  to the bottom of the hook ranges from about 1.0 cm to about 2.0 cm; outer width of the hook  34  ranges from about 2.0 mm to about 6.0 mm; diameter of the concave portion of the hook  34  ranges from about 1.0 mm to about 3.0 mm; length of the lid flange  42  ranges from about 0.5 cm to about 1.5 cm; width of the lid flange  42  ranges from about 1.0 mm to about 3.0 mm; and width of the container gasket  36  and the lid gasket  40  ranges from about 1.0 mm to about 3.0 mm. 
         [0025]    In another embodiment, the plastic container device  10  has a liquid capacity of 120 ml with the following dimensions: diameter of the lid  14  is about 6.0 cm; length of the lid screw threads  32  and the container screw threads  22  is about 1.5 cm; length of the container  12  from the bottom  30  of the container  12  to the bottom of the container screw threads  22  is about 7.0 cm; thickness of the container  12  from the outer side wall  16  to the inner side wall  18  is about 1.3 mm; length of hook  34  from the upper rim  20  of the container  12  to the bottom of the hook is about 1.5 cm; outer width of the hook  34  is about 4.0 mm; diameter of the concave portion of the hook  34  is about 2.0 mm; length of the lid flange  42  is about 1.0 cm; width of the lid flange  42  is about 2.0 mm; and width of the container gasket  36  and the lid gasket  40  is about 2.0 mm. 
         [0026]    In other embodiments of the invention, the volume capacity of the plastic container device  10  may be 500 ml, 480 ml, 460 ml, 440 ml, 420 ml, 400 ml, 380, 360 ml, 340 ml, 320 ml, 300 ml, 280 ml 260 ml, 240 ml, 220 ml, 200 ml, 180 ml, 160 ml, 140 ml, 100 ml, 80 ml, 60 ml or 40 ml, with dimensions for each volume capacity plastic container device increased or reduced proportionate to the dimensions disclosed above for the 120 ml plastic container device  10 . 
         [0027]    Suitable materials for manufacturing the container  12  and lid  14  include polymeric materials, which include, without limitation, polystyrene, polypropylene, polyethylene glycol, or any other suitable plastic material that has strength and durability. 
         [0028]    Container and lid gaskets  36 ,  40  for use in the invention may be made from any suitable material, such as elastomers commonly used to manufacture gaskets, which includes, without limitation, rubber gaskets configured as O-rings. The shape of the gaskets  36 ,  40  may be, without limitation, rectangular, circular, D-shaped, or X-shaped. In an embodiment, the gaskets  36 ,  40  are rectangular. In an embodiment, the size of the two gaskets  36 ,  40  is identical. In another embodiment, the size of the two gaskets  36 ,  40  is different, with the container gasket  36  having a smaller size than the lid gasket  40 . In all embodiments, the container gasket  36  and the lid gasket  40  used in the invention have a shape that provides for complete contact with their mating surfaces, i.e., the upper rim  20  and the lid flange  42 , respectively. 
         [0029]    During use, after a liquid sample is collected in the interior of the container  12 , the lid  14  is closed over the container  12  by engagement of the complementary screw threads  22 ,  32  and rotatable movement of the lid  14 . In use, when the lid  14  is being closed over the container  12 , first the lid gasket  40  in the annular groove  38  mates with, and is compressed upon, the upper rim  20  of the container  12  to form a tight seal. Then, the annular flange  42  inserts into the hook  34  in the container  12  which contains the container gasket  36 , which is compressed by the flange  42  to form a second tight seal. The lid flange  42  is configured to fit tightly in the hook  34  of the container  12  due to the lid flange  42  having a width that is substantially the same as the inner width of the hook  34 . Further, the container gasket  36  used in the invention has a width that is substantially the same as the inner width of the container hook  34 . 
         [0030]    Importantly, therefore, when the lid  14  is closed over the container  12 , the lid gasket  40  and the container gasket  36  form two independent, internal, tight seals so that the contents of the container is completely leak-proof and air tight. Further, in the event that the plastic container  12  and/or lid  14  is deformed in shape due to temperature or pressure changes in the environment, or because the plastic container  12  is stored for an extended period of time, because the gaskets  36 ,  40  are tightly compressed in their respective locations, the integrity of the leak proof and air tight seal is maintained, even from gradual air seepage into or out of the container  12 , which typically occurs over time. The important advantage of the present invention, therefore, is the ability to completely seal the liquid contents of the container  12  from any leakage out, and from any air seepage into and/or out, of the container  12  for extended periods of time, due to the two internal, independent seals, and from environmental conditions, such as mechanical stressors, rigors encountered during transportation, especially air transport, and fluctuations in temperature and atmospheric pressure. 
         [0031]    While the invention has been particularly shown and described with reference to embodiments described above, it will be understood by those skilled in the art that various alterations in form and detail may be made therein without departing from the spirit and scope of the invention, as defined by the appended claims.