Abstract:
The present invention relates to a system for coupling cylindrical sections to form an assembly of thermal or similar containers, where coupling to form the assembly is effected by an internally threaded connecting ring, normally carried at the base of an upper section, to the exteriorly threaded upper circumference of a lower section. The sections may be separated from one another internally to define chambers of discrete volume by screwing an exteriorly threaded section-separating into the upper and/or lower end of each cylindrical section.

Description:
BACKGROUND OF THE DISCLOSURE 
     Previous to this invention there is no known coupling system of cylindrical sections for containers which provides the advantages of this one. 
     Cylindrical containers presently known in the market are generally of two types: a first formed entirely of a single unitary longitudinally extensive wall which encompasses a defined volumetric capacity, and a second formed of container sections coupled together to define either a single enclosed volume or a plurality of smaller enclosed, divided volumes (see U.S. Pat. Nos. 2,326,414 and 4,444,324). 
     SUMMARY OF THE INVENTION 
     The present invention is concerned with a novel mechanism for coupling two or more containers of the second type. Conventional coupling mechanisms of this second type have proven undesirable because they offer little or no airtightness or stability between the joined or coupled areas. Moreover, uncoupling of the adjoining sections may be achieved inadvertantly upon mere rotation of one section relative to the other section, thus resulting in loss of contents within the sections. 
     The coupling system of the present invention overcomes all the disadvantages of the conventional coupling systems by the provision of a coupling ring disposed externally of, and carried by, one section for connecting the one section to a second section. In this way, precise and hermetic connections of different sections can be achieved with the use of internal connecting rings, and assembly of the container is achieved via threaded external rings. The invention also contemplates varying the container&#39;s volumetric capacity as desired, by screwing in internal separation caps or internal connecting rings, thus respectively decreasing or increasing the number of sections practically without limit. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will be best understood by referring to the following detailed description when considered in conjunction with the accompanying drawings in which: 
     FIG. 1 illustrates a side sectional view of one container section; 
     FIG. 2 illustrates an upper plan view of the holding ring of the present invention assembled with the external ring; 
     FIG. 3 shows a side sectional view of the external ring; 
     FIG. 4 shows a side sectional view of two joined sections; 
     FIG. 5 shows a side sectional view of two joined sections and an internal section separating cap; 
     FIG. 6 illustrates a side sectional view of an assembly of containers with internal caps and internal connecting rings; and 
     FIG. 7 shows a side view of the assembled container. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring first to FIG. 1, the specific form for each container section can be appreciated from the illustrated lateral cross-sectional view taken through the container longitudinal axis of symmetry. Section walls 1 exhibit, at upper and lower regions, a thickness of smaller dimension than the thickness of the walls at middle regions. The upper region defines an internal thread 2 and an external thread 3. The lower region of the section is essentially identical in form to the upper region, except that the external threaded surface is replaced with a circumferential opening 4. This opening is preferably, but not necessarily, of rectangular shape, and houses the holding ring 5 of the external ring 6. The holding ring 5 rotates freely together with the threaded external ring relative to the immediately adjacent lower section wall, while being axially held within the opening of that section. 
     The specific features of the coupling between the external ring 6 and the holding ring 5 can be more clearly observed with reference to FIG. 2. The holding ring presents a longitudinally extensive cylindrical form and includes about its external surface equidistantly spaced, radially inwardly projecting grooves with outwardly projecting projections 8 therebetween 7. External ring 6 includes, on its inner surface, equidistantly spaced, substantially identical threaded-projections 7a and grooves 8a which are correspondingly configured with the grooves 7 and projections 8 of holding ring 5 for receipt therein with a substantially perfect fit. The upper region of the external ring 6 (see FIG. 3) defines a threaded formation 15 which extends continuously through the internal surface of said ring. The projections 8 of the holding ring 5 assemble with the longitudinal grooves 8a of the external ring, with the grooves 8a terminating at the upper threaded region. The specific coupling between the threaded external ring 6 and the holding ring 5 permits this assembly to rotate upon screwing or unscrewing the external ring relative to the lower section to be connected, while simultaneously permitting longitudinal movement of the external ring, either upwards or downwards, relative to the holding ring, where such downward movement is limited by the upper threaded region 15 of external ring 6, while upward movement of the external ring with respect to the holding ring 5 unscrewed next from the upper external threaded area of its respective section permits removal of the ring 5 from the container section opening 4. 
     Connection of lower and upper cylindrical sections when using internal separating caps 11 is effected by first screwing each cap 11 into its respective upper and lower container section at the internally threaded region, and then bringing the externally threaded upper region 3 of a lower section into engagement with the holding ring and external ring assembly mounted at the lower region of an upper section and rotating the assembly to screw the external upper region of the lower section thereinto. By so doing, the lower section moves longitudinally with respect to the holding ring and both sections are joined in perfect longitudinal alignment. On the other hand, connection of upper and lower cylindrical sections is first effected, when using an internal connecting ring 9 (FIG. 4) by screwing ring 9 into one of the lower section upper region or the upper section lower region, and then screwing the other section&#39;s threaded region onto the threaded portion of the ring 9 projecting from the section within which it is first screwed. Thereafter, the external ring 6 including the holding ring is rotated about the upper section while simultaneously being urged longitudinally downwardly along the upper section toward externally threaded region 3 so that as ring 6 is rotated, region 3 is screwed into the ring 6 and the two sections are securely affixed together. External ring 6 therefore acts as a double fixation element which prevents either section from being accidentally unscrewed. 
     Referring more particularly to FIG. 4, there is shown a side sectional view of two sections transversely cut in their middle area, illustrating the essentials of the coupling system for the cylindrical sections. 
     The internal ring 9, circumferentially threaded throughout its external surface, is first screwed into the lower internal threaded surface of the upper section and then screwed into the upper internal threaded surface of the lower section, perfectly joining both sections and hermetically sealing their interior through the rubber seal rings 10 which adhere against the internal walls of the sections. This latter joining of the ring 9 with the upper internal threaded surfaceof the lower section is followed by rotation of the external ring 6 for effecting a screw-attachment to the external surface of the lower section 3. This internal ring 9 allows for volumetrical communication between both sections. 
     In viewing FIG. 5, as well as FIG. 4, an appreciation of the coupling system, incorporating the section-separating internal ring 9 section-enlarging internal cap 11, can be obtained. Like the ring 9, cap 11 includes a circumferentially threaded external surface which fits the lower or upper internal thread of each section. 
     Each cap 11 is configured to screw precisely into the lower internal threads of an upper section and the upper internal threads of a lower section, and therefore separate the volumetrical cavities of the sections which are connected. 
     Each cap 11 screws into its respective section individually, pressing with its upper or lower edge that section&#39;s seal packing 10, which preferably is in the form of a ring. 
     FIG. 6 depicts the container with three coupled sections as well as a base and the respective capping portion 13. The base 12 is essentially cylindrical, and presents a threaded surface exteriorly of its upper circumference which can be assembled with the threaded external holding ring 6 associated with an upper section. Additionally base 12 performs the function of permitting the internal rings 9 or section separating caps 11 to be stored when they are not being used. The cap or personal use container 13, which presents a circumferentially threaded surface in its lower area 14, couples to the container section located therebelow by being screwed on the upper circumferentially threaded region of that section. As shown in FIG. 6 the two uppermost sections are connected by an internal connecting ring 9 having a circumferentially external threaded surface, while the next lower section and the section above to which it is secured includes the internal separating caps which in turn limit and separate the internal communication of both sections. 
     FIG. 7 shows the container&#39;s shape after the sections have been assembled. 
     It will be obvious to those skilled in the art that various changes may be made without departing from the scope of the invention and the invention is not to be considered limited to what is shown in the drawings and described in the specification.