Abstract:
A snap-fit arrangement for joining component parts, such as tubular sections and fittings includes a male coupling and a female coupling. A portion of the male coupling extends from one component part and includes cantilever prongs with enlarged heads. The exposed portion of the male coupling and prong heads are structured and disposed for insertion into another component part and through the female coupling until the prong heads exit the inner end of the female coupling and snap outwardly into locked engagement, thereby releasably connecting the two component parts.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention is directed to snap fit attachment structures and, more particularly, to a snap fit arrangement using a male coupling and female coupling with interlocking cantilever prongs for joining component parts in the assembly of an article of manufacture.  
         [0003]     2. Discussion of the Related Art  
         [0004]     Many products are packaged and shipped by the manufacturer to stores in a collapsed form in order to reduce shipping costs as well as warehouse storage and store shelf space. In many instances, the product remains collapsed in its original packaging until sold to a consumer. In particular, furniture items (e.g. tables, cabinets, bookcases, shelving, shoeracks, etc.) are typically shipped to stores in a box consisting of an array of individual parts packaged neatly in a compact package. Instructions and hardware for assembling the item are typically included in the box. To save shelf space and reduce costs, many stores sell items of this nature to the end consumer in the original manufacturer&#39;s box. This also allows the consumer to more easily transport the item in their automobile to their home or other destination where the item will be assembled and used. The cost saved by the manufacture and store by eliminating assembly is typically passed on to the consumer, along with the task of assembling the item. Depending upon the item and the manner of installation, the consumer may need tools, supplies, (e.g. glue, hardware, etc.) and various equipment to complete the assembly. This can make the task more difficult and frustrating, particularly if some or all of the needed tools and supplies are not provided by the manufacturer.  
         [0005]     The ability to assemble articles of manufacture without use of tools, hardware, glue, etc. is extremely convenient and particularly attractive to the average consumer who typically possesses minimal skills, patience and the tools needed to assemble an article with the use of hardware such as screws, bolts, nuts, and the like.  
         [0006]     Snap-in or snap fit connection of component parts is probably the most common method of easy, do-it-yourself assembly that avoids use of tools, hardware, glue, etc. However, the overall strength of the assembled structure is sometimes compromised when using a snap fit method of connection.  
         [0007]     Accordingly, there remains a need for a snap fit arrangement and method for joining two or more components together in the assembly of an article of manufacture which is rigid, strong and avoids the need for special tools and hardware. Moreover, there is a need for a high strength snap fit arrangement which joins tubular sections to various fittings and which can be adapted for use in the assembly of a wide variety of items such as, but not limited to, shelf supports, tables, chairs, cabinets, shoe racks, merchandise stands in stores, sign supports, animal cages, barricades and the like without the need of any tools, hardware, glue or additional supplies.  
       OBJECTS AND ADVANTAGES OF THE INVENTION  
       [0008]     With the foregoing in mind, it is a primary object of the present invention to provide a structural arrangement for joining tubular sections and fittings without the use of tools, hardware or other materials.  
         [0009]     It is a further object of the present invention to provide a structural arrangement for joining pipe sections to various fittings without the use of tools, adhesives or other materials.  
         [0010]     It is still a further object of the present invention to provide a structural arrangement for snap fit connection of pipe sections and fittings in the assembly of an article, such as a table, shoe rack, shelf support or the like.  
         [0011]     It is still a further object of the present invention to provide a structural arrangement for joining pipe sections and fittings without the use of tools or adhesives and, wherein the joined pipe sections and fittings are separable from one another for subsequent collapsing, reassembly or reconfiguration.  
         [0012]     It is still a further object of the present invention to provide a structural arrangement for snap fit joining of pipe sections and fittings in the assembly of an article, and wherein the snap fit structural arrangement is adapted for repeated joining and separation of the component pipe sections and fittings.  
         [0013]     It is yet a further object of the present invention to provide a snap fit arrangement for joining PVC component parts together in an assembly of an article of manufacture which is rigid, strong and avoids the need for tools, hardware, glue and other material and equipment.  
         [0014]     These and other objects and advantages of the present invention are more readily apparent with reference to the following detailed description and accompanying drawings.  
       SUMMARY OF THE INVENTION  
       [0015]     The present invention is directed to a snap-fit structural arrangement for joining tubular sections and fittings in the assembly of an article (e.g. table, shoe rack, shelf support, etc.) includes a male coupling and a mating female coupling. The male coupling includes a first end portion sized for snug fitted frictional receipt within an open port of a fitting and an opposite second end portion of reduced exterior dimension to form a shoulder between the first and second end portions. Two or more prongs are integrally formed with the second end portion and are flexible inwardly towards a hollow axial core. The female coupling is hollow and has a tapered end and an exterior dimension that is sized for snug fitted, frictional receipt within the open end of a pipe section. A flange on the opposite end of the female coupling limits travel through the pipe section and butts against the open end when fully inserted. The second end portion of the male coupling is sized and configured for axial passage through the female coupling until enlarged heads on the prongs exit the tapered inner end of the female coupling. The outer sides of the enlarged heads are tapered to promote insertion and passage of the second end portion of the male coupling through the female coupling, with the prongs being urged inwardly from a relaxed state by the interior wall surface of the female coupling. Upon exiting the inner end of the female coupling, the enlarged prong heads release outwardly to the relaxed state so that an underside of the enlarged head engages the inner end of the female coupling, thereby releasably locking the male coupling to the female coupling. The underside of the enlarged prong heads is angled so that a sufficient outward pulling force on the male coupling will result in inward flexing of the prongs and release of the prong heads from the end of the female coupling, thereby permitting removal of the male coupling. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]     For a fuller understanding of the nature of the present invention, reference should be made to the following detailed description taken in conjunction with the accompanying drawings in which:  
         [0017]      FIG. 1  is an exploded perspective view of the snap fitting of the present invention, including a male coupling and a female coupling shown in relation to a pipe section and a four way fitting;  
         [0018]      FIG. 2  is an isolated cross-sectional view showing the male coupling in snap fit attachment to the female coupling and joining the pipe section to the fitting;  
         [0019]      FIG. 3A  is a side elevational view of the female coupling of the present invention;  
         [0020]      FIG. 3B  is a side elevational view of the male coupling of the present invention;  
         [0021]      FIG. 4A  is a cross-sectional view taken along the line indicated by the arrows  4 A- 4 A in  FIG. 3A ;  
         [0022]      FIG. 4B  is a cross-sectional view taken along the plane indicated by the arrows  4 B- 4 B in  FIG. 3B ; and  
         [0023]      FIG. 5  is an isolated cross-sectional view showing the male coupling in snap fit attachment with the female coupling. 
     
    
       [0024]     Like reference numerals refer to like parts throughout the several views of the drawings.  
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0025]     The snap fit assembly of the present invention is shown throughout  FIGS. 1-5  and is generally indicated as  10 . The snap fit assembly  10  is particularly suited for joining tubular segments or pipe sections (e.g. PVC pipe sections) to either other pipe sections or fittings (e.g. L-shaped, T-shaped, cross shaped, 3-way, 4-way, etc.) for interconnection between pipe sections or as terminal ends of pipe sections (e.g. end caps). The use of fittings is particularly desirable to provide added strength and rigidity to an assembled article, such as a table, shoe rack, shelf support or the like. Use of fittings between the pipe sections further provides for multi-directional attachment of the pipe sections in the assembly of the particular article of manufacture.  
         [0026]     In a preferred embodiment, the snap fit assembly  10  includes a male coupling  20  and a female coupling  30 . The preferred arrangement is to fit the male coupling  20  within the one or more open ends  24  of a particular fitting, such as the 4-way fitting  22  shown in  FIG. 1 . The female coupling  30  is preferably fitted within the open ends  34  of tubular pipe sections  32 . As described hereinafter, the male and female couplings are cooperatively structured and disposed for snap fit, abutting attachment of the pipe sections  32  to the one or more fittings  22  in the assembly of an article.  
         [0027]     The male coupling  20  has a hollow interior  40  between opposite open ends  41 ,  42 . The structure of the male coupling surrounding the hollow interior is formed to include a plug portion  50  and a connector portion  60 . The plug portion has a larger outer cross-sectional dimension (e.g. outer diameter) compared to the outer cross-sectional dimension of the connector portion  60 , thereby forming a shoulder or abutment surface  52  at the juncture where the outer dimensions of the plug and connector portions abruptly change. The outer dimension of the plug portion is specifically sized for congruent, snug fit within the open end of the fitting  22  or a pipe section section  32  so that an outer surface  54  of the plug portion is disposed in frictional engagement with an inner surface  26  of the fitting or pipe section, thereby providing a press fit without the use of adhesives. It should be noted, however, that use of adhesives is contemplated within the scope of the invention and, may be desirable in some instances. In one preferred embodiment, the male coupling  20  is integrally molded with the fitting  22  as a single piece.  
         [0028]     In the example shown in the drawings, one end zone  56  of the plug portion  50  is tapered to promote insertion of the plug portion within the open end of the fitting. When fully inserted in the fitting, the end of the plug portion engages an abutment shoulder  28  within the interior of the fitting, thereby insuring that the shoulder  52  between the plug portion  50  and connector portion  60  is positioned in flush alignment with the open end surface  29  of the fitting  22 .  
         [0029]     The connector portion  60  is defined by a tubular wall  62  which extends from the shoulder  52  to the distal end  58 . The tubular wall has an outer surface  64  and in inner surface  66 . A pair of oppositely disposed prong members  70  are integrally formed with the wall of the connector portion between a pair of parallel open ended slots  72  extending longitudinally from the distal end  58  and terminating prior to the shoulder  52 . The arrangement of the slots  72  provides an integrated flex joint which permits the prongs  70  to flex inwardly and outwardly relative to the wall structure of the connector portion upon application of an external force to heads  76  of the prongs. The heads  76  are formed with an angled face  77  and catch surface  78  which protrude outwardly beyond the exterior dimensions of the wall structure  62  when the prongs  70  are in a relaxed state.  
         [0030]     The female coupling  30  is provided with a hollow interior  80  extending between opposite open ends  84 ,  86  to define a through passage. A main central portion  82  of the female coupling  30  is sized and configured for congruent, snug fit within the open end  34  of the pipe section  32  so that an outer surface  88  of the female coupling is disposed in frictional engagement with an inner surface  35  of the pipe section. An inner end zone of the female coupling  30  is provided with an exterior tapered dimension  90  to promote insertion of the female coupling within the open end  34  of the pipe section  32  for snug, press fit attachment thereto. In a preferred embodiment, no adhesives are required for attachment of the female coupling  30  to the pipe section  32 . It is noted, however, that use of adhesives is contemplated within the scope of the invention and, in some instances, it may be desired to use an adhesive substance to fix the female coupling to a pipe section. In the one preferred embodiment, the female coupling  30  is integrally molded with the pipe section  32  as a single piece.  
         [0031]     In the example shown in the drawings, the opposite end of the female coupling is provided with an annular flange  92  surrounding the open end  84 . An underside surface  93  of the annular flange buts against the end of the pipe section when the female coupling is fully inserted therein. Accordingly, the annular flange  92  serves as a stop member to limit the distance of insertion of the female coupling  30  within the open end  34  of the pipe section  32 .  
         [0032]     The through passage formed between the opposite open ends  84 ,  86  of the female coupling is specifically sized and configured to permit sliding receipt of the connector portion  60  of the male coupling  20  therethrough. The angled face  77  of the heads  76  of the prongs  70  promotes insertion of the prongs and the wall structure  62  of the connector portion through the open end  84  of the female coupling  30 . As the connector portion  60  travels through the female coupling, the prong members  70  are urged inwardly from the relaxed position with the angled face  77  of the prong members engaging the interior surface  87  of the female coupling. The distance between the opposite ends  84 ,  86  of the female coupling is precisely equal to the distance between the shoulder  52  on the male coupling and the juncture between the angled face  77  and catch surface  78  of the prong heads  76 . Thus, when the connector portion  60  of the male coupling  20  is fully inserted and received through the female coupling  30 , the entire angled outer face  77  of the prong members  70  exits the inner open end  86  of the female coupling, thereby allowing the prong members  70  to return to their relaxed position. As the prong members move outwardly to their relaxed position, the catch surface  78  of each of the prong heads  76  engages a beveled inner surface  96  at the end  86  of the female coupling to thereby lock the male coupling  20  to the female coupling  30 . As seen in  FIGS. 2 and 5 , interlocking of the male and female couplings serves to join the pipe section in flush fitted attachment with the open end of the fitting. The angled arrangement of the catch surface  78  on the prong heads and the beveled inner surface  96  of the female coupling allows for removal and separation of the male coupling from the female coupling upon application of a sufficient outward force which pulls the fitting  22  and pipe sections  32  in opposite directions along their common axis.  
         [0033]     While the instant invention has been shown and described in accordance with a preferred and practical embodiment thereof, it is recognized that departures from the instant disclosure are contemplated within the spirit and scope of the present invention.