Plastic Fence Assembly

This invention relates to plastic fences and more particularly it relates to plastic fences with interlocking hollow rails and posts.

Long life fences of rail and post construction fabricated from non-decoyable materials such as plastic and concrete are known in the art, as set forth, for example in U.S. Pat. Nos. 3,700,213 to W. J. Blease of Oct. 24, 1972 and 4,289,302 to J. L. Montgomery of Sept. 15, 1981.

However, certain deficiencies exist in the prior art including features contributing to high cost, which have limited the use of such fencing construction. For example, complex dies need be made for intricate shapes involved.

It is therefore an objective of the present invention to improve the state of the art by providing low cost plastic fence construction features that produce a pleasing fence design appearance while achieving long wear maintenance free qualtities.

Other features, objects and advantages will be found throughout the following description, the claims and the drawings.

This invention therefore provides interlocking fencing rails and posts simply formed at low cost using extruded plastic members of the type available in high quantity low cost pipe production, namely soil pipe or plastic plumbing pipes. Low cost without compromise of life, appearance and installation features is achieved by novel interlocking features between posts and rails formed by very simple modification of the extruded hollow plastic tubing rail and post members.

Thus, basically both the rails and posts comprise hollow open ended extruded plastic tubings, the posts being cylindrically shaped and the rails being flattened into oval shaped members of predetermined width and thickness. The posts have a top cover cap and have cut through the cylindrical casing axially spaced oval slots for receiving the ends of mating rail members. The rails are ovel shaped of a dimension for snugly fitting the ends into the post slots. Interlocking structure is formed by simply notching the rails at a place near each end to interfit with the post casing at each end of the slots therein. Thus, the ends of the rails are flexibly deformable to manually insert a rail member slightly wider than the length of the post slot thereinto by manual deformation, so that the rail end may be pushed into the post cylinder far enough to snap the notches into registration with the cylinder casing at the ends of the slots.

In the drawings like reference characters are used for similar features in the various views to facilitate comparison, and

FIG. 1 is a perspective view of a fence post fragment embodying the invention;

FIG. 2 is a fragmentary perspective view of the interlocking joint structure between rail and post, as afforded by this invention; and

FIG. 3 is a profile view of a section of fence embodying the invention.

As seen from the drawing, a fence is constructed of a set of spaced posts 15 having ends buried below ground 14. A set of rails 16 is suspended between the posts 15. The shown fence section and post structure can be extended to provide adjoining sections and corner sections by appropriate interfitting of rails in the posts in the manner that is set forth hereinafter.

The posts 15, as best seen from FIG. 1, simply are extruded plastic hollow cylindrical pipe members having rail mounting slots 17 or elongated oval apertures through the casing at two or more axially spaced locations to support the mating rails by insertion of the rail ends thereinto. These slots may be axially along only one line to form the fence section of FIG. 3, thus forming end posts, or they may have either another set of slots diametrically opposed to continue adjacent fence sections or disposed in a plane perpendicular to the fence line to constitute a corner post. Cap 18 is a standard item. The posts may be formed of standard three or four inch diameter plastic plumbing pipe sections of polyvinylchloride or ABS which are solvent, weldable and thus the cap 18 may be a standard plumbing fixture plastic welded in place. A metal pipe could be used at higher cost, and for purposes of this invention is considered an equivalent included in the term plastic.

The rails 16, as best seen from FIG. 2, are also preferably extruded hollow plastic pipes of oval shape having open ends that register into the post slots 17. Thus, the rails 16 simulate flat boards of predetermined width and thickness, rounded into oval shape. The ability to use extruded piping for both the posts and rails avoids the necessity to use expensive dies, etc. in forming interlocking fence members. It is unexpected and unobvious to thus be able to simplify the fencing art and reduce costs over previous constructions such as that of U.S. Pat. No. 3,700,213 hereinbefore identified.

The rails 16 may be interfitted into slots 17 and plastic welded in place if desired, and need not have interlocking structure if the spacing between adjacent posts 15 is within appropriate tolerance with respect to the length of the rails 16. However, mechanically interlocking structure is simpler and thus preferred, and is easily achieved in accordance with this invention by simply cutting, dimpling or notching the rails 16 close to the end at each oval shaped edge 19 in the manner illustrated at 20. Thus, the width of the rails 16 between the edges 19 is slightly greater than the length of the slots 17 in the posts, thereby allowing the end of the rail 16 to be manually flexed and distorted enough to enter the slot 17 and slide into place interlocking the notches 20 onto the post casing at the ends 21 of the slots 17. Thus, the railing material preferably is formed of a suitable manually flexible or distortable plastic as the open end of the rail 16. After mechanically interlocking, plastic welding can occur but is not necessary, nor desirable if the fence is to be later disassembled. Thus, a strong, inexpensive, long lasting fencing assembly of good appearance is afforded by this invention, advancing the state of the art.

Therefore those novel features believed descriptive of the nature and spirit of the invention are defined with particularity in the following claims.