Abstract:
A step assembly that is specifically adapted to assist pets in reaching and/or descending from elevated surfaces is provided. The step assembly has two sidewalls having a plurality of openings in which pegs formed on the sides of individual treads and risers are engaged. The pegs are removably insertable into the openings and include protrusions which create an interference fit upon insertion. Because the treads, risers and side walls are joined by interlocking pegs and openings, the step assembly can be flat packed for shipping, and is easily assembled and disassembled for transportation and/or cleaning.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application 60/908,772, filed Mar. 29, 2007, which is incorporated herein by reference as if fully set forth. 
     
    
     BACKGROUND 
       [0002]    The present invention relates generally to portable steps that are light-weight, easy to assemble and disassemble, flat shippable, and in particular, to portable steps suitable for use by domestic animals in the home, such as small or medium sized dogs, to allow access to various elevated surfaces, for example, a sofa or a bed. 
         [0003]    Domestic animals frequently have difficulty moving safely and comfortably between various elevations. Small pets may not be physically able to reach higher elevations because of their overall size. Further, as pets age and develop health problems, they also may have difficulty reaching elevated surfaces that they were once able to reach, such as couches, chairs, sofas, and beds. 
         [0004]    When a pet is not able to reach an elevation by themselves because of size or age, they must instead receive assistance from their owners or have access to an assisting structure. Pet owners are not always available, or in some cases, are incapable of lifting a pet to an elevated surface due to physical limitations. Further, lifting a pet is not always desirable as many pets do not like to be held or lifted. 
         [0005]    While devices such as ramps and steps are known, they are often heavy or bulky, making them difficult to transport and manipulate once assembled. Alternatively, these devices are not sturdy enough for use by larger pets as well as being generally difficult to assemble and disassemble for transportation or cleaning purposes. 
         [0006]    Therefore, it would be desirable to have a stair assembly which was constructed of a light-weight material and could be easily assembled and/or broken down for transportation or cleaning. It would be further desirable to provide a stair assembly that is specifically adapted for use by pets to prevent slipping and allows for comfortable and confident usage. 
       SUMMARY 
       [0007]    The present invention provides a step assembly specifically adapted to assist pets in reaching and/or descending from elevated surfaces. The step assembly has two sidewalls, each having a plurality of openings in which pegs formed on the sides of individual treads and risers are engaged. The pegs are removably insertable into the openings and include protrusions which create an interference fit with the wall of the opening upon insertion. Because the treads, risers and sidewalls are formed from individual pieces joined by interlocking pegs and complementary shaped openings, the step assembly can be flat packed for shipping, and is easily assembled and disassembled for transportation and/or cleaning. 
         [0008]    In a preferred embodiment, the sidewalls, treads and risers are preferably formed as blow molded polymeric parts. This provides a light-weight, stable construction that not only reduces shipping costs, but also allows for easier manipulation by a pet owner once assembled. The treads are sloped downwardly and have an anti-slip material attached to the top surface(s) thereof. This not only provides a more ergonomic arrangement for the pet, but also reduces the chance of a pet slipping while negotiating the steps. Further, the anti-slip material is preferably removably attached to allow removal for cleaning or replacement due to wear. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    The foregoing summary, as well as the following detailed description of the preferred embodiments of the invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there are shown in the drawings embodiments which are presently preferred. It should be understood, however, that the invention is not limited to the precise arrangements shown. 
           [0010]      FIG. 1  is a perspective view of a portable step in accordance with a first embodiment of the invention taken from the front-right side. 
           [0011]      FIG. 2  is a perspective view of the portable step of  FIG. 1  taken from the rear-left side. 
           [0012]      FIG. 3  is a top view of the portable step of  FIG. 1 . 
           [0013]      FIG. 4  is a left side elevational view of the step of  FIG. 1 . 
           [0014]      FIG. 5  is an enlarged detail view showing the peg-hole connection utilized in the portable step according to the invention. 
           [0015]      FIG. 6  is an exploded view of the tread used to form the portable step of  FIG. 1 . 
           [0016]      FIG. 7  is a bottom view of the tread of  FIG. 6 . 
           [0017]      FIG. 8  is a front elevational view of the step of  FIG. 6 . 
           [0018]      FIG. 9  is a cross-sectional view taken along lines  9 - 9  in  FIG. 7 . 
           [0019]      FIG. 10  is a side elevational view of the right sidewall used in the portable step of  FIG. 1 . 
           [0020]      FIG. 11  is an elevational view of the inner skin of the sidewall of  FIG. 10 . 
           [0021]      FIG. 12  is an elevational view of the left sidewall used in the portable step of  FIG. 1 . 
           [0022]      FIG. 13  is an elevational view of the inner skin of the sidewall in  FIG. 12 . 
           [0023]      FIG. 14  is a perspective view of a riser used to form the portable step of  FIG. 1 . 
           [0024]      FIG. 15  is a front elevational view of the riser of  FIG. 14 . 
           [0025]      FIG. 16  is a top view of the riser of  FIG. 14 . 
           [0026]      FIG. 17  is an enlarged side view showing the pegs on the ends of the riser of  FIG. 14 . 
           [0027]      FIG. 18  is a perspective view of a support bar used to assemble the step of  FIG. 1 . 
           [0028]      FIG. 19  is an enlarged end view of the support bar of  FIG. 18 . 
           [0029]      FIG. 20  is a perspective view of a step according to a second embodiment of the present invention. 
           [0030]      FIG. 21  is a rear-left perspective view of the step of  FIG. 20 . 
           [0031]      FIG. 22  is a rear-right perspective view of the step of  FIG. 20 . 
           [0032]      FIG. 23  is a front perspective view of the step of  FIG. 20 . 
           [0033]      FIG. 24  is a right side elevational view of the partially assembled step according to  FIG. 20 . 
           [0034]      FIG. 25  is a right side elevational view of the right sidewall used to form the step of  FIG. 20 . 
           [0035]      FIG. 26  is an elevational view of the inside skin of the sidewall of  FIG. 25 . 
           [0036]      FIG. 27  is a left side elevational view of the left sidewall used to form the step of  FIG. 20 . 
           [0037]      FIG. 28  is a perspective view of the tread used in the step of  FIG. 20 . 
           [0038]      FIG. 29  is a bottom perspective view of the tread of  FIG. 28 . 
           [0039]      FIG. 30  is a side elevational view of the tread of  FIG. 28 . 
           [0040]      FIG. 31  is an enlarged potion of the sidewall of  FIG. 27  showing the formation of the openings used to assemble the steps according to the present invention. 
           [0041]      FIG. 32  is an enlarged view of the inner skin section of the sidewall shown in  FIG. 31  showing the formation of the openings used to assemble the steps in the present invention. 
           [0042]      FIG. 33  is an enlarged cross-sectional view through one of the openings in the sidewall. 
           [0043]      FIG. 34  is an enlarged detail view of a peg on a tread, riser, or support bar. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0044]    Certain terminology is used in the following description for convenience only and is not considered limiting. Words such as “front”, “back”, “top” and “bottom” designate directions in the drawings to which reference is made. This terminology includes the words specifically noted above, derivatives thereof and words of similar import. Additionally, the terms “a” and “one” are defined as including one or more of the referenced item unless specifically noted. In the drawings, “(TYP)” has been used to indicate that an element number is “typical” for all instances of a particular element where more than one of the elements are shown (for example the opening  20  designated as “(TYP)” in  FIG. 1 ). 
         [0045]    The preferred embodiments of the present invention will be described with reference to the drawing figures where like numerals represent like elements throughout. 
         [0046]    Referring to  FIGS. 1-4 , a portable step  10  in accordance with the first preferred embodiment of the present invention is shown. As can be seen most clearly in  FIGS. 1 and 2 , the step  10  includes a right sidewall  12  and a left sidewall  14 , each having a plurality of connection openings  20  extending therethrough. Two individual treads  22  and two risers  40  are connected between the sidewalls  12 ,  14  using pegs  34 ,  54 , respectively, which extend from each side of the treads  22  and risers  40  that engage in the openings  20 . Additionally, as shown in detail in  FIG. 2 , a support bar  60  with pegs  61  is connected between the sidewalls  12  and  14  at the back, bottom corner of each for additional support. 
         [0047]    As shown in  FIG. 1 , preferably the treads  22  are angled downwardly between an angle of approximately 5° and 15°, more preferably between an angle of 8° and 12°, and most preferably at an angle of 10° with respect to horizontal. Additionally, the treads  22  preferably have a depth of approximately twice the height of a riser  40 . In the first preferred embodiment, the risers  40  are approximately five inches tall and the treads have a depth of approximately 10 inches or more. This ratio can vary such that the depth of the tread  22  is preferably between 1.5 and 2.5 times a height of the riser  40 . Preferably, the risers  40  and treads  22  have a curved profile at the front of each step to allow for easier use. 
         [0048]    Referring to  FIGS. 6-9 , the construction of the tread  22  is shown in detail. The tread  22  is preferably formed from a blow molded polymeric material and includes a top skin  24  and a bottom skin  26 . A depression  25  is preferably provided in the top skin  24  for mounting of an anti-slip material  30 , such as a piece of carpet, rubber, or any other suitable material. In a preferred embodiment, the anti-slip material  30  is attached through hook and loop type textile fastening strips, such as VELCRO®, with the hook and loop textile fastening strips of one type  29  being located on the top skin  24 , preferably in further recesses  33 , and opposing hook and loop type textile fastener strips  32  being located on the anti-slip material  30 . 
         [0049]    The pegs  34  preferably extend from the edge walls  28  on either side of the tread  22 . The pegs  34  are preferably constructed with an enlarged cylindrical shoulder  35  adjacent to the base and include an enlarged diameter end section  36  having tabs  37  located at approximately the 3 o&#39;clock and 9 o&#39;clock positions. Preferably, two pegs  34  are provided on each side of the tread  22 . 
         [0050]    Referring to  FIGS. 7-9 , the bottom skin  26  of the tread  22  preferably includes stiffening depressions  27  located therein. The stiffening depressions  27  provide support for the top skin  24  as shown most clearly in  FIG. 9  and provide additional stiffness for the tread  22 . 
         [0051]    While the preferred embodiment of the tread  22  is preferably blow molded from polypropylene, those skills in the art will recognize that the tread  22  could be formed from other materials and by other means, and that one key feature of the present invention is to provide the releasably engageable pegs  34 , preferably having the indicated configuration for assembly of the treads  22  with the sidewalls  12 ,  14 . 
         [0052]    Referring to  FIGS. 10-13 , the sidewalls  12 ,  14  are shown in detail. The sidewalls  12 ,  14  each include an outer skin  15  and an inner skin  16 . The openings  20  are defined through the outer and inner skins  15 ,  16  of both sidewalls  12 ,  14 . The openings have a continuous wall that extends between the inner and outer skins  15 ,  16 . As shown in  FIGS. 10 and 12 , recesses  21  are provided on both sides of the openings  20  in corresponding positions to the tabs  37  of the pegs  34  for a first set of the openings, and in corresponding positions to the tabs  57  of the pegs  54  for a second set of the openings. As shown in  FIGS. 11 and 13 , each of the openings  20  has a circular shoulder  19  defined therein which corresponds to the shoulder  35  at the base of the pegs  34  of the tread as well as to the shoulders  55  and  62  on the pegs  54  and  61  of the risers  40  and support bar  60 , which are described in further detail below. The circular shoulder  19  in the opening  20  preferably provides a snug fit for the pegs  34 ,  54 ,  61  so that a good weight transferring connection is provided. Preferably, the pegs  34 ,  54 ,  61  can be pressed through the openings  20  and the tabs  37 ,  57  and  64  can engage behind the shoulder  19  in the openings  20  to hold the treads  22 , risers  40  and support bar  60  to the sidewalls  12 ,  14 , as shown in  FIG. 5 . 
         [0053]    The sidewalls  12 ,  14  are preferably also blow molded from polypropylene, although other materials and/or methods of fabrication can be utilized. The blow molded configuration allows the continuous wall defining the openings  20  between the inner and out skins  15 ,  16  to flex for assembly and disassembly. 
         [0054]    Referring to  FIGS. 14-17 , one of the risers  40  is shown in detail. The risers  40  are preferably also formed from blow molded polymeric material, preferably polypropylene, and include a front skin  42  and a back skin  44 , shown best in  FIG. 2 , with an edge wall  46  extending between the front skin  42  and back skin  44 . Pegs  54 , which are similar to the pegs  34  as described above, extend from both sides of the riser  40 . The peg  54  includes the circular shoulder  55  located at the base and an enlarged end  56  having tabs  57  located at the 12 o&#39;clock and 6 o&#39;clock positions. The openings  20  in the sidewalls  12  and  14  include corresponding recesses  21 , as indicated in detail in  FIGS. 10 and 12 . The shoulders  55  provide a snug fit with the circular recesses that define the shoulder  19  in the inner skins  16  of the side walls  12  and  14 , as discussed above. 
         [0055]    Preferably, as shown in  FIG. 2 , the back skin  44  of the riser  40  includes stiffening depressions  45  to provide added stiffness to the risers  40 . It is envisioned that these stiffening elements, including those formed on the sidewalls and treads, are not limited to being formed as depressions. Similar contours including ribs, protrusions, and other suitable forms may be utilized to accomplish the desired stiffening effect. 
         [0056]    While it is preferred that the risers  40  are formed from blow molded polymeric material, those skilled in the art will recognize that the risers  40  can be formed from other suitable materials and/or other construction methods. 
         [0057]    Referring to  FIGS. 18 and 19 , the support bar  60  is shown in detail. The support bar  60  preferably includes pegs  61  at each end. The pegs  61  have the same configuration as the pegs  34  and  54  for the treads  22  and risers  40 , respectively. This includes the shoulder  62  which is adapted to fit into the circular recess formed by the shoulder  19  of the openings  20  in the inner skin  16  of the sidewalls  12 ,  14 . An enlarged end  63  with tabs  64  is similarly provided for engagement through the openings  20 . 
         [0058]    Preferably, the support bar  60  is formed from a polymeric material, such as polypropylene, and may include stiffening ribs or recesses  66  which extend longitudinally along the support bar  60  for added stiffness. 
         [0059]    In the preferred embodiment, the material used for the treads, sidewalls, risers and support bar is polypropylene having a wall thickness of about 0.1 inches. However, other polymeric or non-polymeric materials could be utilized, and the hollow wall construction is not required, although preferred. Other light-weight solid or sandwiched panel constructions could also be employed. 
         [0060]    In order to assemble the portable step  10 , preferably sidewalls  12  and  14  are provided along with two of the treads  22 , two of the risers  40  and one support bar  60 . Preferably, the pegs  34  of each tread  22  are pressed into the corresponding openings  20  of the left sidewall  14  and the pegs  54  of the risers  40  are similarly pressed into the openings  20  of the left sidewall  14 . One end of the support bar  60  is similarly inserted into the corresponding opening  20  in the left sidewall  14 . The right side wall  12  is then positioned over the pegs  34 ,  54  and  61  of the treads  22 , risers  40  and support bars  60 , respectively. By pressing the sidewalls  12 ,  14 , toward one another, the pegs  34 ,  54 ,  61  pass through the inner shoulders  19  of the openings  20  and the tabs  37 ,  57 ,  64  engage behind the shoulder  19  and are aligned in the recesses  21 , visible in the outer skins  15  of the sidewalls  12 ,  14 . The anti-slip material  30 , such as pieces of carpet can be applied to the treads  22  using the hook and loop type textile fastening strips  29 ,  32 . 
         [0061]    This provides a light weight step which is suitable for use by pets for climbing to and from an elevated surface, with the extended treads which are sloped downwardly providing ease of use and creating less trepidation in the pet as it moves up and down the portable step  10 . 
         [0062]    Referring now to  FIGS. 20-24 , a second embodiment of a step  100  in accordance with the present invention is shown. The second embodiment of the step  100  has three treads  122  and three risers  140  located between two sidewalls  112 ,  114 . The second embodiment of the step  100  is similar to the first embodiment of the step  10  in its construction and similar parts have been identified with similar element numbers for ease of reference. 
         [0063]      FIGS. 21 and 22  show rear perspective views of the step  110  indicating the location of the sidewalls  112 ,  114 , the treads  122 , the risers  140  and the support bar  160  connected at the rear bottom corners of the sidewalls  112 ,  114 . As shown, the sidewalls  112 ,  114 , treads  122  and risers  140  are all preferably formed of a polymeric material, preferably by blow molding, and include stiffening depressions in the inner skins which are not apparent in normal use. As shown in  FIG. 23 , preferably anti-slip material  130 , such as pieces of carpeting are affixed to the treads  122 , preferably using hook and loop type textile fastening strips  129 , shown in  FIG. 28  and corresponding strips on the underside of the anti-slip material  130 , similar to the strip  32  described above in connection with the first preferred embodiment. 
         [0064]    Referring to  FIG. 24 , a partially assembled right side elevational view of the second embodiment of the step  100  is shown. Specifically, the left sidewall  114  is shown with the treads  122 , risers  140  and support bar  160  connected via the respective pegs  134 ,  154  and  161  inserted in the corresponding openings  120  in the sidewall  114 . As discussed above in connection with the first embodiment of the step  10 , the right sidewall  112  is then placed over the partially assembled step as shown in  FIG. 24  with the upwardly directed pegs  134 ,  154  and  161  being aligned with the corresponding openings  120  in the right side wall  112 , and the assembly is then pressed together such that the pegs  134 ,  154 ,  161  extend through the openings  120  and the enlarged diameter ends  136 ,  156 ,  163  with the tabs  137 ,  157  and  164  engage behind the shoulders  119  of the openings. 
         [0065]    Referring to  FIGS. 25 and 26 , the right sidewall  112  is shown in detail with the outer skin  115  shown in  FIG. 25  and the inner skin  116  shown in  FIG. 26 . Stiffening depressions  117  are provided in the inner skin  116  for added stiffness to the sidewall  112 . The recesses  121  for the tabs of the pegs are shown in  FIG. 25  and the shoulders  119  in the openings  120  are shown most clearly in  FIG. 26 . 
         [0066]      FIG. 27  illustrates the left sidewall  114  with the outer skin  115 . The inner skin  116  of the left sidewall  114  is similar to the inner skin  115  of the right sidewall  112 , as shown in  FIG. 22  as well. 
         [0067]      FIGS. 28-30  show the construction of the tread  122  which includes the hook and loop type textile fastening strips  129  located in recesses  133  as well as the recess  125  in the upper skin  124  for the anti-slip material  130 . The construction of the pegs  134  with the circular shoulder  135  at the base along with the enlarged diameter end  136  with tabs  137  is also clearly illustrated. The construction of the tread  122  is similar to the tread  22  and preferably the ratios of tread depth to riser height are as discussed above, although in the second preferred embodiment, the tread  122  is only approximately 9 inches deep at the sidewalls as opposed to the tread  22  of the first embodiment of the invention being approximately 11 inches deep at the sidewalls. 
         [0068]    The construction of the risers  140  is the same as that of the risers  40  discussed above and accordingly has not been repeated. 
         [0069]    Referring to  FIGS. 31 and 32 , an enlarged detail of a portion of a sidewall  12 ,  14 ,  112 ,  114  is shown in the area of an opening  20 ,  120 .  FIG. 31  shows the outer skin of the sidewall  12 ,  14 ,  112 ,  114 , wherein the shoulder  19 ,  119  within the opening  20 ,  120  is clear as well as the recesses  21 ,  121  for receiving the tabs located at the ends of the pegs  34 ,  54 ,  61 ,  134 ,  154 ,  161 . Referring to  FIG. 32 , the inner skin of the sidewalls  12 ,  14 ,  112 ,  114  is illustrated at the opening  20 ,  120 . Here the enlarged diameter of the opening  20  which corresponds to the diameter of the shoulder  35 ,  55 ,  63 ,  135 ,  155 ,  163  at the base of the pegs  34 ,  54 ,  61 ,  134 ,  154 ,  161  is shown. 
         [0070]    In the preferred embodiment, the shoulder  35 ,  55 ,  63 ,  135 ,  155 ,  163  at the base of the peg has a diameter of about 0.70 inches and corresponds to the diameter of the opening in the inner skin of the sidewall  12 ,  14 ,  112 ,  114 . The shoulder  19 ,  119  in the opening  20 ,  120  has an inside diameter of approximately 0.68 inches. The peg has a diameter of approximately 0.62 inches at the intermediate portion and the enlarged diameter end of the peg has a diameter of approximately 0.65 inches. The tabs  37 ,  57 ,  64  on the ends of the peg extend to an effective diameter of approximately 0.69 inches. While the approximate dimensions from the preferred embodiments of the steps  10 ,  100  have been given, those skilled in the art will recognize that other dimensions can be utilized in order to form the connections between the treads, risers, support bars and sidewalls in order to form the steps  10 ,  100 . 
         [0071]      FIGS. 33 and 34  provide enlarged detail cross-sections of the openings  20 ,  120  and the pegs  34 ,  54 ,  134 ,  154 . The pegs  61 ,  161  are of the same construction as well. 
         [0072]    An advantage of the steps  10 ,  100  according to the present invention is that the treads and sidewalls are generally flat and can be easily flat packed and the risers are only slightly curved also allowing for generally flat packing for shipping. Due to the hollow wall construction, the steps  10 ,  100  according to the invention provide exceptional strength while maintaining a light weight that allows not only for lower costs for shipping but also easier handling by the ultimate end user. 
         [0073]    Additionally, the peg and opening connection used by the steps  10 ,  100  according to the invention allow for repeated assembly and disassembly for cleaning and/or storage. The removable anti-slip material  30 ,  130  is also easily removable for cleaning and/or replacement. 
         [0074]    While the preferred embodiments have been described with two or three steps, the invention can be applied to steps having a different number of treads and risers, and for steps of various widths and heights, and the invention is not limited to the two preferred configurations noted above. The present invention is also not limited to a step assembly for use by pets, and combinations described herein may be used with any construction that aids in moving between different heights. 
         [0075]    Having thus described in detail several embodiments the present invention, it is to be appreciated and will be apparent to those skilled in the art that many physical changes, only a few of which are exemplified in the detailed description of the invention, could be made without altering the inventive concepts and principles embodied therein. It is also to be appreciated that numerous embodiments incorporating only part of the preferred embodiment are possible which do not alter, with respect to those parts, the inventive concepts and principles embodied therein. The present embodiment and optional configurations are therefore to be considered in all respects as exemplary and/or illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all alternate embodiments and changes to this embodiment which come within the meaning and range of equivalency of said claims are therefore to be embraced therein.