Patent Publication Number: US-6991550-B1

Title: Climbing steps for playground structure

Description:
FIELD OF THE INVENTION 
   The invention relates to children&#39;s playground equipment, and more particularly to climbing steps for playground equipment. 
   BACKGROUND OF THE INVENTION 
   Playground equipment often includes an elevated platform on which children can play, and from which they can access slides and other equipment. Typically, there are steps connected to the elevated platform so that children can climb up to the elevated platform from ground level. 
   SUMMARY OF THE INVENTION 
   The invention provides an improved climbing steps construction that is easy to assemble and install, and that is well-suited for the needs of the children using the steps. 
   More specifically, the invention provides a climbing steps rail set including a first molded plastic rail having a lower end configured to rest on a lower support surface, an upper end configured to be coupled to an elevated support structure, and a first plurality of apertures formed in the rail and configured to receive respective first ends of steps to be supported by the rail set. The rail set further includes a second molded plastic rail having a lower end configured to rest on the lower support surface, an upper end configured to be coupled to the elevated support structure, and a second plurality of apertures formed in the rail and configured to receive respective second ends of the steps to be supported by the rail set. 
   In one aspect of the invention, each of the rails includes a graspable handrail extending substantially the entire length of the rail from the lower end to the upper end. In another aspect of the invention, each of the rails includes a recessed pocket adjacent each of the plurality of apertures for facilitating the insertion of a fastener into a step received in the aperture. In yet another aspect of the invention, each of the rails includes a strengthening cavity formed in the rail. 
   The invention also provides a playstation including an elevated support structure positioned above a lower support surface, and climbing steps coupled to the elevated support structure for allowing a user to climb from the lower support surface to the elevated support structure. The climbing steps include a first molded plastic rail having a lower end configured to rest on the lower support surface, an upper end configured to be coupled to the elevated support structure, and a first plurality of apertures formed in the rail. The climbing steps further include a second molded plastic rail having a lower end configured to rest on the lower support surface, an upper end configured to be coupled to the elevated support structure, and a second plurality of apertures formed in the rail. Additionally, the climbing steps also include a plurality of steps positioned intermediate the first and second rails. Each step includes a first end received in a corresponding one of the first plurality of apertures, and a second end received in a corresponding one of the second plurality of apertures. 
   In one aspect of the invention, the width of the climbing steps is variable depending on the length of the plurality of steps positioned intermediate the first and second rails. In another aspect of the invention, the rails form about a sixty degree angle with the lower support surface. In yet another aspect of the invention, each of the rails has a body thickness along a substantial portion of the rail and a mounting portion at the upper end that is thinner than the body thickness. A transition between the body thickness and the thinner mounting portion defines a shoulder configured to align the rail for mounting to the elevated support structure. In yet a further aspect of the invention, the elevated support structure includes first and second generally vertical members. The shoulder of the first rail is generally aligned with an edge of the first generally vertical member and the shoulder of the second rail is generally aligned with an edge of the second generally vertical member. 
   Other features and advantages of the invention will become apparent to those skilled in the art upon review of the following detailed description, claims, and drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a partial perspective view of a playstation including climbing steps embodying the invention. 
       FIG. 2  is an exploded perspective view of the climbing steps shown in  FIG. 1 . 
       FIG. 3  is a right side view of the climbing steps shown in  FIG. 1 . 
       FIG. 4  is a section view taken along line  4 — 4  of  FIG. 3 . 
       FIG. 5  illustrates the rails of the climbing steps without assembled steps. 
   

   Before one embodiment of the invention is explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or being carried out in various ways. Also, it is understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including”, “having” and “comprising” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. 
   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 1  illustrates a playstation  10  of the type typically used by children for recreational play. The playstation  10  includes a plurality of legs  14  (only one is shown) that support an elevated support structure or platform  18  above a lower support surface, such as the ground  22 . As shown, a slide  26  may be coupled to the playstation  10  to allow children to slide from the platform  18  down to the ground  22 . While not shown, other rides and climbing features (e.g., swings, monkey bars, etc.) can also be coupled to the playstation  10 . 
   A set of climbing steps  30  is coupled to the playstation  10  to provide a way for children to climb from the ground  22  up to the platform  18 . Of course, the climbing steps  30  can also be used to climb from the platform  18  back down to the ground  22 . As best illustrated in  FIG. 2 , the climbing steps  30  are constructed of first and second one-piece, molded plastic rails  34 ,  38 , respectively, which receive and support a plurality of steps  42  therebetween. In the illustrated embodiment, the rails  34 ,  38  are molded from a suitable plastic using a conventional blow molding technique. Of course, other suitable molding techniques (e.g., rotational molding) can also be used. 
   In the illustrated embodiment, the first rail  34  forms the left side of the climbing steps  30 , while the second rail  38  forms the right side of the climbing steps  30 . The first and second rails  34 ,  38  are substantially mirror images of one another, but are not interchangeable. In other words, the first rail  34  must be used as the left side rail of the climbing steps  30  and the second rail  38  must be used as the right side rail of the climbing steps  30 . This facilitates construction and installation of the climbing steps  30  in that there is only one way to assemble the climbing steps  30  based on the construction of the rails  34 ,  38 . Furthermore, by having distinct left and right rails, the assembled climbing steps  30  are more aesthetically pleasing. Of course, those skilled in the art will understand that the rails  34 ,  38  could also be modified such that each rail could be used as either a left-side or a right-side rail. 
   Each rail  34 ,  38  includes a first or lower end  46  configured to rest on the ground  22 , and a second or upper end  50  configured to be coupled to the platform  18 . Each rail  34 ,  38  further includes an inner surface  54  and an outer surface  58 . As best shown in  FIG. 4 , the inner and outer surfaces  54 ,  58  are spaced apart to define a rail body thickness T b  that is generally constant over a substantial portion of each rail  34 ,  38 . In the illustrated embodiment, the upper end  50  of each rail  34 ,  38  defines a mounting portion  62  that is thinner than the rail body thickness T b  and that includes a plurality of apertures  64  configured to receive fasteners  66  (see  FIG. 1 ) for securing the mounting portions  62  to respective first and second generally vertical members  70 ,  74  of the playstation  10 . It should be noted that the vertical members  70 ,  74  could also extend to the ground  22  in a manner similar to the leg  14 . 
   As best shown in  FIG. 3 , the transition between the portion of the rail  38  having the rail body thickness T b  and the mounting portion  62  defines a shoulder  78  configured to align the rail  38  for mounting to the generally vertical member  74 . As shown in  FIG. 1 , the generally vertical members  70 ,  74  are constructed of standard 4″×4″ lumber. To align the mounting portions  62  of the rails  34 ,  38  for mounting, the rails  34 ,  38  are positioned as shown in  FIG. 1  such that the shoulders  78  are generally aligned with and potentially even abut an outer edge or surface of the members  70 ,  74 . Of course, the vertical members  70 ,  74  could also be made of other size lumber (e.g., 2″×4″s), in which case the shoulders  78  of the rails  34 ,  38  may not physically abut the vertical members. Nonetheless, the shoulders  78  will provide a visual alignment guide for positioning the mounting portions  62  properly with respect to the vertical members. The location of the apertures  64  on the mounting portions  62  is also selected such that the rails  34 ,  38  can be mounted to vertical members of differing sizes. 
   As shown in  FIGS. 2 and 5 , each rail  34 ,  38  further includes a plurality of apertures  82  sized and configured to receive a respective end of a step  42 . In the illustrated embodiment, the apertures  82  are each sized to receive an end of a step  42  constructed of standard 2″×6″ lumber. As illustrated in the figures, the rails  34 ,  38  each include four, generally equally-spaced apertures  82 , with the lower three apertures  82  extending completely through the rails  34 ,  38 , and the upper-most aperture  82  not extending completely through the rails  34 ,  38 . Of course, all of the apertures  82  could extend completely through the rails  34 ,  38 , or likewise, none of the apertures  82  need extend completely through the rails  34 ,  38 . 
   As shown in  FIG. 1 , the top step  42  is positioned in the rails  34 ,  38  such that its upper surface is generally aligned with the upper surface of the platform  18 . With this configuration, the top step  42  forms an extension to the platform  18  that facilitates climbing and descending the climbing steps  30 . Of course, the top step  42  need not be level with the upper surface of the platform  18 , and in an alternative embodiment, the platform  18  can be located above the top step  42  such that the child takes an additional step up from the top step  42  to reach the platform  18 . 
   Additionally, the number of apertures  82  in each rail  34 ,  38  can vary depending upon the desired number of steps  42  and the rails could receive and/or be modified to receive other sizes of steps  42  as well (e.g., 2″×4″s, 2″×10″s, etc.). However, benefits to using standard 2″×6″ lumber as opposed to smaller 2″×4″ lumber include larger horizontal stepping surfaces for a child&#39;s feet and reduced horizontal gaps between successive steps. It should also be noted that the steps  42  need not be constructed of wood, but can alternatively be constructed of other suitable materials, such as plastics. 
   Each rail  34 ,  38  also includes a recessed pocket  86  adjacent each aperture  82 . The recessed pockets  86  facilitate the insertion of fasteners  90  (e.g., screws or nails—see  FIG. 2 ) into the ends of the steps  42  to secure the ends of the steps  42  to the respective rails  34 ,  38 . To assemble the steps  30 , a first end of a first step  42  is inserted into an aperture  82  in the first rail  34 . This procedure is repeated for each step  42 . Next, the second end of each step  42  is inserted into the corresponding aperture  82  in the second rail  38 . The fasteners  90  are inserted into the respective ends of the steps  42  within the recessed pockets  86  to secure the steps  42  in place with respect to the rails  34 ,  38 . 
   The rails  34 ,  38  each also include molded-in strengthening cavities  94  formed between the apertures  82 . A strengthening cavity  94  is also formed on each rail  34 ,  38  below the lower-most aperture  82 . In the illustrated embodiment, the strengthening cavities  94  are generally oval-shaped adjacent the inner surfaces  54  and taper to an apex  96  (see  FIG. 4 ). The cavities  94  are oriented substantially vertically. Of course, any suitable cavity shape and orientation can be used, and the number and location of the cavities  94  can be varied as desired. 
   As shown in  FIG. 3 , the rails  34 ,  38  are configured such that when mounted to the vertical members  70 ,  74 , the rails form an angle α of about sixty degrees or less with the ground  22 . In the illustrated embodiment, the angle α is about sixty degrees. Each of the rails  34 ,  38  is further constructed to include an integrally-formed graspable handrail  98  that extends substantially the entire length of the rail  34 ,  38  from the lower end  46  to the upper end  50 . The handrail  98  is configured to meet ASTM F 1148-00 requirements for handgrasps, and provides a readily graspable component that a child  100  (see  FIG. 4 ) can grasp through the entire climb or descent of the climbing steps  30 . As best illustrated in  FIG. 4 , the handrail  98  is formed to include oppositely facing undercut portions  99  such that the child&#39;s fingers and thumb can wrap around a portion of the handrail  98  for improved grasping. 
   The rails  34 ,  38  provide great flexibility for varying the overall width of the climbing steps  30 . As illustrated in  FIG. 1 , the assembled climbing steps  30  have an overall width of about twenty-four inches. This enables the four steps  42  to be cut from a single, eight-foot length of standard 2″×6″ lumber. However, the overall width of the climbing steps  30  can be easily varied to any desired width dimension simply by using the appropriate length of wood for the steps  42 . 
   The fact that the climbing steps  30  can be constructed at the site of the playstation  10 , as opposed to being either pre-assembled or a single, molded unit further facilitates the ability to package the rails  34 ,  38  in a compact manner. As shown in  FIG. 5 , the rails  34  and  38  can be positioned and packaged such that the respective inner surfaces  54  engage one another. The inner surfaces  54  can each include interlock members in the form of a protrusion  102  and a recess  106 . As seen in  FIG. 5 , the first rail  34  includes a protrusion  102  positioned near the lower end  46  and a recess  106  positioned near the upper end  50 . The second rail  38  includes a protrusion  102  positioned near the upper end  50  to mate with the recess  106  in the first rail  34 , and a recess  106  positioned near the lower end  46  to mate with the protrusion  102  on the first rail. These interlocking members help orient the rails  34 ,  38  with respect to one another and substantially prevent relative movement (e.g., sliding) between the rails  34 ,  38  when placed together for packaging. Of course, the specific locations, configurations, and numbers of interlocking members can be varied as desired. 
   The lower end  46  of the rails  34 ,  38  is also designed to facilitate storage and display of the rails  34 ,  38  prior to assembly. As best shown in  FIG. 3 , the lower end  46  of each rail  34 ,  38  includes an angled surface  110  that is inclined from the remainder of the lower surface configured to rest on the ground  22 . The angled surface  110  is generally normal to long edges of the rails  34 ,  38  such that when the rails  34 ,  38  are standing generally vertically (i.e., the long edges of the rails are oriented generally vertically), the angled surface  110  provides a generally horizontal surface capable of supporting the rails  34 ,  38  in that generally vertical orientation. This feature is particularly useful for the storage and display of packaged rail sets in retail stores. 
   Various features of the invention are set forth in the following claims.