Patent Publication Number: US-6341464-B1

Title: Siding panel with interlock

Description:
This application is a continuation of U.S. patent application Ser. No. 09/053,475, filed Apr. 1, 1998 now U.S. Pat. No. 6,065,260. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates generally to a panel with an elongated, normally horizontal interlock useful for holding overlapping panels in engagement and presenting a pleasing ornamental appearance. More particularly, it is concerned with a panel having an improved interlock structure which provides improved attachment, increased durability, and greater rigidity to the panel. 
     2. Description of the Prior Art 
     Vinyl and metal siding is used to provide a decorative and protective sheathing over buildings. The siding is typically nailed to the underlying structure, with successive overlapping courses of siding panels nailed to the building walls. Most typically, the siding presents the appearance of clapboards in lapping arrangement which provides a decorative appearance and sheds rain or other moisture. 
     It is desirable to provide an interlock structure to connect adjacent overlapping siding panels. A decorative siding interlock panel is shown in U.S. Pat. No. Design 382,351, which provides a panel which includes an interlock but hides the interlock from the view of an observer when applied to a building. While this siding panel design has ornamental advantages, it is believed that structural improvements would enhance the performance of the panel in use. 
     Thus, there has developed a need for a siding panel which is not only attractive, but also provides improved rigidity, durability, and interlocking performance. 
     SUMMARY OF THE INVENTION 
     These objects have largely been solved by the siding panel of the present invention. That is to say, the siding panel hereof retains the attractive appearance of the prior art panel, but yields improved performance and resists damage during installation by providing a superior interlock design. 
     The siding panel hereof is preferably formed as an elongated panel presenting a nailing strip along the top with a receiver positioned just below the nailing strip in normal orientation. The receiver is configured to present a recess formed by bending the panel to project forwardly of the surface of the underlying structure and then returning in a pair of lower and upper bends forming a serpentine loop. A stretch portion of the panel projects downwardly and adjacent the surface of the underlying structure from the serpentine loop. One or more stretches extend downwardly to the bottom of the panel, which is provided with a projection for insertion in snap-fitting relationship with the receiver. The projection is formed by bending the panel inwardly toward the structure from the lowermost stretch, providing a second bend extending normally upwardly, and a third or return bend forming a hairpin with the free leg oriented normally downwardly and away from the top of the panel. 
     The projection preferably has a greater transverse dimension than the clearance between the lower bend and the stretch portion of the panel located above and adjacent thereto, so that an interference fitting is created. As a result, a positive and audible “snap” sound is created when the projection moves past the clearance into the receiver. Moreover, the free leg serves to bias the projection against the receiver of the next upper panel, to enhance the holding power of the connection. Because of this holding relationship, as the panel forming a part of an adjacent and upper course has its projection inserted into the receiver of the lower panel already nailed in place, the installer may use the interlock thereby created to hold the panel in position while retrieving a level, hammer or other tool before nailing the upper panel in place. This greatly facilitates the installation of the panels and reduces labor. Moreover, the configuration of the interlock permits easy discoinection between adjacent panels by simply pulling downwardly on the uppermost panel to release the connection. As an added benefit, the improved panel configuration has been found to provide substantial improvements in rigidity in resisting deflection of the panel, wherein testing has revealed improvements of up to 40% for 12 foot length panels. In addition, the rounded edge of the projection is less likely to catch or bind during insertion into the receiver, and less likely to break since the free edge, which typically thins out during manufacturing, is oriented away from the direction of insertion. 
     As a result, a superior panel is provided which provides both qualitative and quantitative levels of improvement over prior art panels. The benefits noted above and other improvements will be readily apparent to those skilled in the art with reference to the drawings and the attached description. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a foreshortened perspective view of a siding panel in accordance with the present invention in its normal horizontal orientation, showing the nailing strip along the top of the panel and the projection along the bottom of the panel; 
     FIG. 2 is a side elevational view of the siding panel hereof, showing the receiver located below and forwardly of the nailing strip; 
     FIG. 3 is an enlarged fragmentary side elevational view of adjacent overlapping upper and lower panels of the present invention, showing the lower panel nailed to a supporting structure and the upper panel positioned for insertion of its projection into the receiver of the lower panel; and 
     FIG. 4 is an enlarged fragmentary side elevational view similar to FIG. 3, showing the projection of the upper panel fully inserted into the receiver of the lower panel in interlocking engagement. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to the drawing, a siding panel  10  in accordance with the present invention is preferably manufactured as single elongated article from a unitary sheet of synthetic resin such as polyvinyl chloride. One preferred technique is extruding the panel  10  which is shaped by passing through dies to achieve the desired configuration. The panel presents a front side  12  which may be embossed with a pattern such as simulated woodgrain and a back side  14  which typically lacks such embossing. Broadly speaking, the panel presents a nailing strip  16 , a receiver  18 , at least one and preferably a plurality of stretches  20  and  22 , and a base  24  having a projection  26 . The panel  10  hereof is described in its typical generally horizontal orientation as shown in FIG. 1, but may also be oriented vertically or at other angles as desired. 
     The nailing strip  16  is positioned uppermost on the panel  10  and includes a substantially flat span extending downwardly from edge  28 , the strip  16  presenting a plurality of perforations  30  therein. The perforations  30  are typically elongated horizontally to permit expansion and contraction along the length of the panel  10  due to changes in temperature. The receiver  18  is positioned just below the nailing strip  16  to allow adjacent panels  10 A and  10 B to overlap as shown in FIGS. 3 and 4, thereby aiding in shedding precipitation. The receiver  18  includes a forward bend  32  to provide space for folding of the panel  10  to receive a projection  26  of an adjacent panel, and a curved face  34  which combine to present an ornamentally pleasing configuration. The curved face  34  extends normally downwardly to an outer hairpin bend  36  which routes the following arc segment  38  upwardly and toward the nailing strip  16  as shown in FIG.  2 . The outer hairpin bend  36  includes an inner edge  40 . Arc segment  38  continues in a curved presentation to liner bend  42  which ends in first stretch  20 . A serpentine loop  44  is presented by outer hairpin bend  36 , arc segment  38  and inner bend  42 , with a recess  46  presented thereby. A gap G between inner edge  40  and first stretch  20  has a reduced transverse dimension which is smaller than the transverse dimension of the widest dimension R within the recess  46 . 
     The first stretch  20  continues downwardly toward the base  24 . A second stretch  22  is normally located below the first stretch  20 , and is staggered below the first stretch by a lap  50 . Stretches  20  and  22  are shown in a conventional straight clapboard presentation, but may be provided in other well-known presentations such as dutch lap or ship lap stylings. Lap  50  is intended to present the appearance of clapboard wood siding and includes a nose  52 , a shelf  54  and a trough  56 . Base  24  is positioned at the bottom of second stretch  22 , and configured to be similar in appearance to lap  50  when panels  10 A and  10 B are interlocked and viewed facing the front side  12 . 
     The base  24  includes an elbow  58  and a rearwardly projecting base leg  60 . Crook-shaped projection  26  extends upwardly toward nailing strip  16  from the base curve  62  at the rear portion of base leg  60 . The projection  26  includes a flange  64  and a cantilever leg  66  which is oriented opposite the flange  64  and joined thereto by a return bend  68 . Return bend  68  causes the angle between the flange  64  exiting the base curve  62  and the tip  70  at the end of cantilever leg  66  to be more than 90 degrees, and preferably more than 180 degrees. The flange  64  is curved at its upper end  72  adjacent return bend  68 , causing projection  26  and base curve  62  to have a serpentine appearance. 
     The configuration of projection  26  and receiver  18  is complemental to permit interlocking of overlapping panels  10 A and  10 B as illustrated in FIGS. 3 and 4, where the panel  10 A is shown fixed to a supporting structure  74  such as a building by nails  76  inserted through projections  30  and pounded into the structure  74 . In FIG. 3, the projection  26  of the upper panel  10 B is shown moving upwardly just prior to locking into the receiver  18  of lower panel  10 A. The cantilever leg  66  is flexing toward flange  64  to permit the projection  26  to move past gap G. The unflexed transverse dimension P of projection  26  is normally greater than the dimension G of gap, but by flexing the return bend  68  and the bending of cantilever leg  66  toward the flange  64 , the projection  26  is able to slide into the recess  46  in receiver  18  as shown in FIG.  4 . The curved upper end  72  of flange  64  facilitates the movement of projection  26  past gap  48 , and because return bend  68  presents an outside convex surface  78  and is located uppermost on the projection  26  as it moves into receiver  18 , entry of the projection is facilitated and not hindered by any sharp edge. Further, the tendency of the tip  70  to thin out as it leaves the mold is of less importance as the return bend  68  enters the recess  46  first and thereby acts as a leading edge effectively protecting the tip  70  at the trailing end of the projection. 
     After entry of the projection  26  into the recess  46  in interlocking relationship as shown in FIG. 4, the cantilever leg  66  flexes back to its original position to further facilitate a good interlocking relationship. Cantilever leg of uppermost panel  10 B provides a biasing force away from the first stretch  20  of panel  10 A and thus serves to restore the unflexed transverse dimension P and thus resist downward movement of the panel  10 B out of interlocking engagement with panel  10 A. This permits the installer to let go of the upper panel  10 B temporarily while it remains attached to the lower panel  10 A. The strip  16 , receiver  18 , stretches  20  and  22 , base  24  and projection  26  extend substantially the length of the panel  10 , which are typically available in elongated lengths of twelve feet, sixteen feet or even longer. 
     It may thus be seen that without materially changing the outward appearance from that shown in U.S. Pat. No. Design 382,351, a superior panel  10  is provided with improved rigidity, interlocking, and protection during connection.