Abstract:
A tool for positioning a plurality of templates with respect to a curved rail includes a flexible spine that carries a plurality of templates. Each of the templates defines an opening adapted to guide a cutting tool to form a picket hole in the rail. The templates are evenly spaced along the longitudinal direction of the flexible spine so that the picket holes are evenly spaced when cut. A clamp may be associated with each template to hold the tool with respect to the rail.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   This application claims priority from U.S. patent application Ser. No. 60/461,567 filed Apr. 9, 2003; the disclosure of which is incorporated herein by reference. 

   BACKGROUND OF THE INVENTION 
   1. Technical Field 
   The present invention generally relates to methods and tools used to form the picket holes in curved fence rails. More particularly, the present invention relates to a flexible tool that automatically adjusts to the curvature of the rail to automatically position a plurality of templates at the locations for the picket holes. 
   2. Background Information 
   Low maintenance vinyl fences and vinyl decking are becoming increasingly popular as their appearance approaches traditional wood structures. These structures generally have top and bottom rails that extends between vertical posts. A plurality of spaced parallel pickets are connected to the top and bottom rails and are evenly spaced between the posts. Picket holes must be cut in the upper surface of the bottom rail and in the lower surface of the top rail to receive the pickets. In order to maintain parallel and evenly spaced pickets, the picket holes must be carefully planned and cut. When the top and bottom rails are straight, the planning and cutting is not too difficult. A router may be used with a simply template to cut the openings along the longitudinal centerline of the rails. 
   Structures with curved rails are also becoming increasingly desired given their aesthetic features and their ability to simulate traditional wooden structures. Those skilled in the art of vinyl structures have found the task of cutting picket holes in curved vinyl rails difficult. The radii of curved vinyl rails varies because of the material properties and methods of forming the curved rails. The different radii prevent a fixed template from being used to locate the picket holes. As such, the location of each picket hole must be measured manually. Once the hole location is marked, a template is position and a cutting tool, such as a router, is used to form the hole. Although this process is effective, the art desires a method and a tool for quickly and easily laying out and cutting all the picket holes in a curved rail. 
   BRIEF SUMMARY OF THE INVENTION 
   The invention provides a tool that is used to locate the picket holes on a curved fence rail. The tool automatically adjusts to the curvature of the rail while automatically positioning a plurality of templates at the proper locations for the picket holes. The tool generally includes a flexible spine with a plurality of templates mounted to the spine. In one embodiment of the invention, the tool includes a clamp aligned with each template to securely hold the curved rail with respect to the templates. 
   The invention also provides a method for forming the picket holes in a curved rail wherein the curved rail is slid into a flexible tool that automatically adjusts its curvature to the curvature of the rail. The method includes the step of fixing the position of the tool with respect to the rail and forming the picket holes in the rail. 

   
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       FIG. 1  is a perspective view of a curved fence section having a pair of curved fence rails disposed between a pair of fence posts. 
       FIG. 2  is a top plan view of the first embodiment of the tool of the present invention. 
       FIG. 3  is a bottom plan view of the first embodiment of the tool of the present invention. 
       FIG. 4  is an enlarged view of the encircled portion of  FIG. 3 . 
       FIG. 5  is a top plan view of the first embodiment of the tool and a curved rail. 
       FIG. 6  is a top plan view of the first embodiment of the tool with a curved rail clamped into the tool and ready for cutting. 
       FIG. 7  is a section view taken along line  7 — 7  of  FIG. 6 . 
       FIG. 8  is a section view taken along line  8 — 8  of  FIG. 6  showing a cutting tool ready to cut a picket hole. 
       FIG. 9  is a view similar to  FIG. 8  showing the cutting tool forming the picket hole. 
       FIG. 10  is a top plan view of the second embodiment of the tool of the present invention. 
       FIG. 11  is a section view taken along line  11 — 11  of  FIG. 10 . 
       FIG. 12  is a top plan view of the second embodiment of the tool and a curved rail. 
       FIG. 13  is a top plan view of the first embodiment of the tool with a curved rail clamped into the tool and ready for cutting. 
       FIG. 14  is a section view taken along line  14 — 14  of  FIG. 13 . 
   

   Similar numbers refer to similar parts throughout the specification. 
   DETAILED DESCRIPTION OF THE INVENTION 
   The two preferred embodiments of the tool of the invention are indicated generally by the numerals  100  and  102  in the accompanying drawings. Each tool  100  and  102  is adapted to automatically adjust itself to the curvature of a rail  104  that is placed within tool  100  or  102 . Each tool  100  and  102  is also adapted to automatically position a plurality of templates  106  with respect to rail  104  so that the picket holes may be cut into curved rail  104  without excessive, time consuming measuring. 
   Each template  106  may be a locating template that is used to mark the picket hole location or a cutting template that defines an opening sized and shaped to receive an appropriate cutting element—such as a router bit—that is designed to cooperate with the opening to cut a picket holes in a surface of rail  104 . In the preferred embodiment of the invention, each opening on each template  106  is sized to cooperate with the collar on a router bit to properly position the router bit ( FIG. 9 ) to cut a perfect opening that receives the end of a picket in a fence  10  ( FIG. 1 ). Each template  106  is designed for the picket that is intended to be used with rail  104 . Different templates  106  are used for different pickets. As such, different tools  100  or  102  may be designed for use with different pickets. Further, different tools  100  or  102  may be designed for use with different picket spacing. Tool  100  and  102  is, however, designed to work with endless degrees of curvature between the upper and lower limits of the tool. In another embodiment of the invention, the positions of the templates with respect to the tool are adjustable so that the tool may be set up for different picket spacing. 
   Each tool  100  and  102  includes a flexible spine  110  that carries templates  106  such that the opening in template  106  is properly positioned with respect to rail  104 . The opening in each template may be centered with respect to the cross sectional width of rail  104  as shown in  FIGS. 7 and 14 . 
   In tool  100 , spine  110  defines a plurality of spaced slots  111  that increase the flexibility of spine  110 . In cross section, the spine on tool  100  has a height equal to its width and may be 1½ inch by 1½ inch in cross section. In this embodiment, the spine acts as its own clamp support as shown in  FIG. 7  such that rail  104  is clamped against spine  110  with a plurality of clamps that are removed from tool  100  when all of the holes are cut in rail  104 . In tool  102 , spine  110  has a thin width compared to its height in cross section. The thin width allows spine  110  to bend without the need for slots  111 . In both embodiments, spine  110  may be fabricated for a flexible material such as plastic lumber. 
   In the second embodiment, a clamp support  112  is attached to spine  110  at each template  106 . A clamp  114  is attached to each clamp support  112  as shown in  FIG. 11  with a portion of spine  110  being disposed between clamp  114  and clamp support  112 . Clamps  114  may be securely mounted (i.e.: with threaded fasteners) to supports  112  such that clamps  114  remain in place after the holes are formed in rail  104 . The clamping force of clamp  114  is adjustable to accommodate variations in rail  104  thickness. 
   In tool  102 , a flexible cover  116  is disposed between each clamp  114  and spine  110  to protect rail  104  and spread the clamping force of clamps  114  to a wider area of rails  104 . Flexible cover  116  may also be fabricated from flexible lumber. Cover  116  has a length at least as long as the span of clamps  114  and may have a length equal to or greater than spine  110 . 
   Each template  106  may have angled sidewalls or angled corners that allow templates  106  to pivot toward each other when a sharply curved rail  104  is inserted into tool  100  or  102  as shown in  FIGS. 6 and 13 . The angles prevent the templates  106  from interfering with each other. 
   In the two embodiments of the invention shown in the drawings, the distance between each template  106  is fixed and the spacing between the template  106  hole and the spine  110  is fixed. In other embodiments of the invention, these distances may be adjustable by providing the templates with adjustable connections. 
   In use, the person needing a curved fence section  10  first forms a pair of rails  104  into the desired curve by know bending techniques. The user then inserts curved rail  104  into tool  100  or  102 . In tool  100 , the person bends tool  100  around curved rail  104  and clamps tool  100  in place as shown in  FIGS. 6  and  7 . In tool  102 , the user slides rail  104  into tool  102  and allows tool  102  to automatically accommodate the curvature of rail  104 . The user then positions one end of tool  100  or  102  with respect to rail  104  to automatically position templates  106  with respect to rail  104 . Tools  100  and  102  also allow the person cutting the holes to view the entire layout before cutting. This overview gives the user the chance to eliminate layout mistakes that would otherwise result in a scrapped piece of material. Each tool  100  and  102  may be used on a straight rail  104  having an infinite radius of curvature to a rail  104  having a radius of curvature that is small enough to cause templates  106  to interfere with each other. 
   In the foregoing description, certain terms have been used for brevity, clearness, and understanding. No unnecessary limitations are to be implied therefrom beyond the requirement of the prior art because such terms are used for descriptive purposes and are intended to be broadly construed. 
   Moreover, the description and illustration of the invention is an example and the invention is not limited to the exact details shown or described.