Patent Publication Number: US-6032695-A

Title: Rail plug

Description:
CROSS REFERENCES TO CO-PENDING APPLICATIONS 
     None. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a plug, and more particularly, pertains to a plug for capping or sealing an open end of a tubular rail or other tubular member. The invention has particular application in conjunction with tubular rails or railing support members on boats, but may be employed with tubular members found in any environment. 
     2. Description of the Prior Art 
     Prior art sealing plugs for closing the open ends of tubular members such as rails or railing support members have required a number of time-consuming installation steps, such as drilling of body holes in the sides of a rail or railing support members for subsequent insertion of screw, bolt or pin members through the body holes into the plug to retain the plug in the open end of the rail or railing support member. Other plugs have been secured into the open end of a rail or railing support member with adhesive, only to have the adhesive deteriorate with the passage of time and with thermal changes, thereby causing the plug to disengage itself from or become loose in the rail or railing support member. Some plugs have formed a close tolerance fit with the interior of a rail or railing support member, but with age or heating and cooling have shrunk and become loose in or disengaged themselves from the rail or railing support member. Clearly what is needed is a plug which can be installed in the open end of a rail or railing support member with a minimum of tools, or even with no tools, which does not require excessive installation labor, and which is not affected by heat, cold or adhesive or material deterioration. The present invention provides such a rail plug. 
     SUMMARY OF THE INVENTION 
     The general purpose of the present invention is to provide a plug to be used to cap or seal the open end of a tubular member such as a rail or railing support member used on a boat or in other environments. Sealing of the open ends of rails or railing support members is accomplished for a variety of reasons. Sealing of a rail or railing support member on a boat prevents one from inserting a finger into the open end of the rail or railing support member where injury could occur during boating activities. Exposed uncapped rails or railing support members present sharp edges or corners which could cause bodily harm if mistakenly contacted. Sealing also prevents insects from entering or building nests in the rail or railing support member. In the plug of the invention, a series of ramped teeth arrays are included on several adjacent sides of the plug for the purpose of frictional engagement with the interior of a rail or railing support member. The teeth are ramped or sloped to provide increasing frictional contact with various wall thickness rails or railing support members. As the plug is inserted further into the rail or railing support member, the teeth are brought into increasing flex contact with the inner surfaces of the rail or railing support member. 
     According to one embodiment of the present invention, there is provided a plug having a plurality of connected planar members extending perpendicularly from a planar surface of a cap member. These connected planar members include horizontally oriented and opposing upper and lower planar panels, vertically oriented and opposing left and right side planar panels extending between the horizontally oriented and opposing upper and lower planar panels, opposing arrays of ramped teeth located on the upper and lower surfaces of the horizontally oriented and opposing upper and lower planar panels and formed integrally therewith, and an array of ramped teeth located on the vertically oriented left side planar panel and formed integrally therewith. An indexing guide bar is located at the junction of the horizontally oriented upper planar panel and the vertically oriented right side planar panel. Together the horizontally oriented upper and lower planar panels, the vertically oriented left and right side planar panels, the indexing guide bar, and the integrally formed arrays of ramped teeth are inserted into the interior of a rail or railing support member and held therein by frictional engagement to fill and plug off the open end of the rail or railing support member. 
     One significant aspect and feature of the present invention is a one-piece plug which frictionally engages the open end of a rail or a railing support member, such as used in marine equipment. 
     Another significant aspect and feature of the present invention is the provision of opposing and adjacent arrays of ramped teeth on the plug which increasingly engage the interior of a rail or railing support member in frictional engagement. 
     Another significant aspect and feature of the present invention is a plug which remains in place even with temperature excursions. 
     Another significant aspect and feature of the present invention is a plug which can be installed with a minimum of tools, or preferably with no tools. 
     Another significant aspect and feature of the present invention is a plug whose installation is not hampered by the need for drilling of holes or installation of holding pins or screws. 
     Another significant aspect and feature of the present invention is a plug which is self-locating and self-aligning. 
     Another significant aspect and feature of the present invention is a plug which seals the open end of a rail or railing support member for prevention of bodily injury. 
     Another significant aspect and feature of the present invention is a plug which seals the open end of a rail or railing support member to prevent the entry of insects, debris, water, and other foreign objects. 
     Having thus described significant aspects and features of an embodiment of the present invention, it is the principal object of the present invention to provide a plug for capping or sealing the open end of a rail or railing support member. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other objects of the present invention and many of the attendant advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, in which like reference numerals designate like parts throughout the figures thereof and wherein: 
     FIG. 1 illustrates an isometric view of a rail plug; 
     FIG. 2 illustrates a side view of the plug; 
     FIG. 3 illustrates a top view of the plug; 
     FIG. 4 illustrates an end view of the plug; 
     FIG. 5 illustrates a side view of the plug in frictional engagement with a rail or railing support member which is shown partially and in cross section; and, 
     FIG. 6 illustrates an end view of the plug within the rail or railing support member looking in the direction of line 6--6 in FIG. 5. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 1 illustrates an isometric view of a one-piece plug 10, such as is used to seal off or close the open ends of rails and railing support members, such as, but not limited to, square or other rectangular or other geometrically configured rails or railing support members, or other structure requiring plugging or capping. The one-piece plug 10, fashioned of plastic, rubber or other such suitable material, includes a cap 12 from which a plurality of rearwardly projecting and connected planar panels extend. An upper planar panel 14 extends horizontally and rearwardly from the cap 12 and includes a horizontally aligned tapered indexing guide bar 16 having a first tapered edge 16a which is widest near the junction of the cap 12 and the first tapered edge 16a and narrowest near a second tapered edge 16b located at the inboard end of the plug 10. With respect to the centerline 20 of the plug 10, the taper of the second tapered edge 16b exceeds that of the first tapered edge 16a so that the second tapered edge 16b serves as an alignment enhancing surface for facilitating insertion of the plug 10 into open rail or railing support member ends, while the first tapered edge 16a serves as an alignment surface for deeper rail or railing support member penetration. With reference to FIGS. 1, 2 and 3, an outwardly protruding array of ramped teeth 18a-18n is located on the upper portion of the upper planar panel 14. The angle or pitch of tooth 18a with respect to the plug centerline 20 is shallower than that of teeth 18b-18n to generally replicate the same angle as presented by the second tapered edge 16b to aid in initial location and insertion of the plug 10 into an open rail or railing support member end. The angle or pitch of teeth 18b-18n with respect to the centerline 20 of the plug 10 is greater than that angle or pitch presented by tooth 18a. As illustrated in FIGS. 2 and 4, a similarly fashioned lower planar panel 22 extends horizontally and rearwardly from the cap 12; however, a lower indexing guide bar is not included. An outwardly protruding array of ramped teeth 24a-24n is located on the lower portion of the lower planar panel 22. The angle or pitch of tooth 24a with respect to the plug centerline 20 is shallower than that of teeth 24b-24n to generally replicate the same angle as presented by the second tapered edge 16b and tooth 18a to aid in initial location and insertion of the plug 10 into an open rail or railing support member end. The angle or pitch of teeth 24b-24n with respect to the centerline 20 of the plug 10 is greater than that angle or pitch presented by tooth 24a. Another outwardly protruding array of ramped teeth 26a-26n, having the same attributes and construction as the arrays of ramped teeth 18a-18n and 24a-24n, is located on the left side planar panel 28, which extends between the upper and lower planar panels 14 and 22 and vertically and rearwardly from the cap 12. Right side planar panel 30 extends between the upper and lower planar panels 14 and 22 and vertically and rearwardly from the cap 12, but does not include an array of ramped teeth. The body of the plug along the centerline can be a partially hollow interior 21 to reduce the content of polymer material or can be solid. 
     FIG. 2 illustrates a side view of the plug 10, where all numerals correspond to those elements previously described. Illustrated in particular is the arrangement of the opposing arrays of ramped teeth 18a-18n and 24a-24n and the array of ramped teeth 26a-26n which engage the interior of a rail or railing support member as shown in FIG. 5. With respect to the horizontally aligned upper planar panel 14 and the centerline 20 of the plug 10, it can be seen that, starting from the right side of the plug 10, the height of the teeth 18a-18n increases incrementally in a ramped fashion from right to left, having a maximum tooth height nearest the cap 12. The ramping of the teeth 18a-18n allows for accommodational frictional engagement with various inside dimensions of rails or railing support members. The teeth 18a-18n, being narrower at the outer teeth tip areas, flex during frictional engagement and flex in increasing degrees along the plurality of teeth 18a-18n to firmly engage the interior of a rail or a railing support member. A number of adjacent teeth in the plurality of teeth 18a-18n progressively and in unison with opposing and adjacent like teeth 24a-24n and 26a-26n grip the interior of the rail or railing support member in wedge-like fashion. 
     FIG. 3 illustrates a top view of the plug 10, where all numerals correspond to those elements previously described. Illustrated in particular are the first and second tapered edges 16a and 16b of the indexing guide bar 16. The taper of the second tapered edge 16b exceeds that of the first tapered edge 16a so that the second tapered edge 16b serves as an alignment enhancing surface for facilitating location and insertion of the plug 10 into the open rail or railing support member end, while the first tapered edge 16a serves as an alignment surface for deeper rail or railing support member penetration. 
     FIG. 4 illustrates an end view of the plug 10, where all numerals correspond to those elements previously described. 
     FIG. 5 illustrates a side view of plug 10 in frictional engagement with a rail or railing support member 32 which is shown partially and in cross section, where all numerals mentioned before correspond to those elements previously described. The rail or railing support member 32 is shown in frictional engagement with teeth 18d-18n on the upper region of the plug 10 and in frictional engagement with teeth 24d-24d on the lower region of the plug 10. Teeth 18n and 24n, having the greatest offset from the centerline 20 of the plug 10, are in flexed impingement with the interior surfaces of the walls 32a and 32b, respectively, of the rail or railing support member 32. Teeth 18e, 18d and 18c and teeth 24e, 24d and 24c tangentially impinge the interior surfaces of the walls 32a and 32b, respectively, of the rail or railing support member 32 in concert with teeth 18n and 24n and in combination to frictionally engage and secure the plug 10 to the interior of the rail or railing support member 32. From right to left, each of the impinging teeth increasingly engages the interior surfaces of walls 32a and 32b of the rail or railing support member 32 in frictional engagement. It can be seen that a rail or railing support member having a thicker wall thickness would additionally engage an increased number of teeth, such as teeth 18b and 18a and teeth 24b and 24a, for purposes of illustration, whereby engagement and flexing of an increased number of teeth would occur and increase the holding power via increased frictional engagement. Teeth 26a-26n engage the interior surface of another wall (see FIG. 6 at 32c) of the rail or railing support member 32 in a similar fashion. The plug 10 is inserted into the end of the rail or railing support member 32 until the cap 12 comes in contact with the end of the rail or railing support member 32. Thus, the plug 10 is incorporated into the end of rail or railing support member 32 to seal the end to prevent entry of fingers as well as other objects such as dirt, insects, moisture and the like. 
     FIG. 6 illustrates an end view of the plug 10 within the rail or railing support member 32 looking in the direction of the line 6--6 in FIG. 5, where all numerals mentioned before correspond to those elements previously described. Illustrated in particular are the walls 32a, 32b and 32c of the rail or railing support member 32 against the interior surfaces of which the respective arrays of ramped teeth 18a-18n, 24a-24n and 26a-26n impinge. Also shown is wall 32d of the rail or railing support member 32. Although the wall 32d can be of uniform thickness throughout, like the walls 32a, 32b and 32c, it is illustrated as having a portion of increased thickness, such as is typical of ordinary rails or railing support members commonly used on boats, such as, but not limited to, a pontoon boat. The tapered indexing guide bar 16 engages the interior surface of wall 32d in the area of lesser thickness and further aids in securing the plug 10 within the open end of the rail or railing support member 32. The different thickness portions of the wall 32d are sometimes characterized as separate walls. Therefore, a rail or rail support member of this ordinary and well-known construction is oftentimes referred to in the art as a five-wall rail or a five-wall tube. 
     Although the plug 10 is illustrated and described as being generally square in shape, the plug 10 could take on rectangular shapes other than square, could be other polygonal shapes, or could even have a geometrical shape other than polygonal for use with rails or railing support members having correspondingly shaped interiors. Also, although the plug 10 is shown as having a hollow form, it could be of solid construction. Still further, the end of the cap 12 can be substantially flat, as illustrated, or can have a rounded form. Hence, neither the precise shape nor the exact form of the plug as illustrated in the drawings shall be deemed to be limiting to the scope of the invention. 
     Various modifications can be made to the present invention without departing from the apparent scope hereof.