Abstract:
A climbing aid for assisting people to move up or down to different levels has steps that can be folded into attached integral handrails that circumscribe the steps when folded so that no parts extend outside of the boundaries of the handrails.

Description:
BACKGROUND OF THE INVENTION 
   This invention relates to aiding people who have difficulty elevating themselves from one level to another, as for example stepping up into and down from a van, or climbing on to an examination table in a doctor&#39;s office or hospital. More particularly my invention relates to portable steps that have handrails and are easily stowable. The handrails on prior foldable steps did not provide adequate support for handicapped or elderly people. Also, when folded, the prior steps took up too much space or had projecting components or irregular outer surfaces that made it difficult to store the folded steps in a confined space. 
   OBJECTIVES OF THE INVENTION 
   Accordingly, it is an object of this invention to provide improved foldable steps with sturdy ergonomically designed handrails that inspire confidence in people that have difficulty stepping up or down. 
   Another object is to produce portable steps that fold inside of their integral handrails so as to provide a relatively smooth exterior surface that has no jagged edges or protruding parts so that the folded steps are stowable in relatively narrow confined spaces. 
   An additional object is to provide foldable steps having handrails that have flat outer surfaces when folded so that the folded steps will lie flat in an vehicle and can have other objects stored on top of them, and the flat outer surfaces of the folded steps also allow them to be easily stored against a flat wall surface or between the flat surfaces of furniture or cabinets. 
   Another object is to provide foldable steps that present a relatively continuous, firm, substantial supporting surface upon which relatively heavy objects can be safely stored when the steps are folded. 
   Another object is to provide foldable steps with relatively smooth outer surfaces that will not mar the surfaces of things that the folded steps are slid on or against or stored on, under or against. 
   A further object is to provide compact, portable, easily stored folding steps that have substantial handrails and are relatively light weight, durable, economical, attractive, easy to use and maintain, and which do not possess defects found in similar prior art folding steps. 
   Other objects and advantages of the folding steps incorporating my invention will be found in the specification and claims and the scope of the invention will be set forth in the claims. 

   
     DESCRIPTION OF THE DRAWING 
       FIG. 1  is a perspective view of an embodiment of foldable steps in accord with this invention, showing the steps in their fully open position. 
       FIG. 2  is a perspective partially broken away view of the foldable steps, showing the steps in their partially open position. 
       FIG. 3  is a perspective view of the foldable steps, showing the steps in their fully closed position. 
       FIG. 4  is an enlarged, schematic, cross sectional view taken generally along the line  4 — 4  in  FIG. 3 . 
       FIG. 5  is a top plan view of the steps in their fully closed position. 
       FIG. 6  is a partially broken away, schematic, side view showing the steps in their open position. 
       FIG. 7  is a cross sectional view taken along the line  7 — 7  in  FIG. 6 . 
       FIG. 8  is a cross sectional view taken along the line  8 — 8  in  FIG. 6 . 
   

   DESCRIPTION OF THE INVENTION 
   The drawing shows a compact, portable, folding climbing aid  10  in accord with my invention, that may be made from strong lightweight plastic or metal, such as aluminum or titanium. The aid  10  has a first fully open expanded position, as shown in FIGS.  1  and  6 – 8 , and a second closed or folded position, as shown in  FIGS. 3–5 . 
   Aid  10  has a first upper step  11  that is located above a second lower step  12  when the aid  10  is in its open position. The step  11  has a front edge  14 , a rear edge  15 , one side edge  16 , an opposite side edge  17 , and a flat tread surface  18 . As shown in  FIGS. 2 ,  7  and  8 , front edge  14  has an attached pivoting end  19  and an unattached free end  20 , and rear edge  15  has an attached pivoting end  21  and an unattached free end  22 . The step  12  has a front edge  23 , a rear edge  24 , one side edge  25 , an opposite side edge  26 , and a flat tread surface  27 . As shown in  FIGS. 2 ,  6  an  8 , front edge  23  has an attached pivoting end  28  and an unattached free end  29 , and rear edge  24  has an attached pivoting end  30  and an unattached free end  31 . The front edge  14  of step  11  has an integral flange  32  and the rear edge  15  has an integral flange  33  extending therefrom. The front edge  23  of step  12  has an integral flange  34  and the rear edge  24  has an integral flange  35  extending therefrom. The side edges of the steps also may have integral flanges extending therefrom. The flanges  32 ,  33 ,  34 , and  35  each have a notch, respectively  36 ,  37 ,  38  and  39 , adjacent their free unattached end. 
   The aid  10  has a first handrail  40  and an essentially identical second hand rail  41 . Handrail  40  has a first leg  42  of predetermined length, a second leg  43  of lesser length, an integral slanting hand grip bar  44  connecting its legs, and an outwardly facing generally flat exterior surface  45 . Handrail  41  has a first leg  46  of predetermined length, a second leg  47  of lesser length, an integral slanting hand grip bar  48  connecting its legs, and an outwardly facing generally flat exterior surface  49 . The handrails  40  and  41  are generally square in cross section with chamfered corners. When in the aid  10  is in its expanded position, the steps  11  and  12  are horizontal and the handrails  40  and  41  are separated at the opposed side edges  16  and  17  and  25  and  26 , respectively, for easy gripping by a person stepping up or down on the steps. 
   A first flat panel beam  55  connects the legs  42  and  43  of handrail  40  and spans the distance separating these legs. Beam  55  has a flat, smooth, outwardly facing exterior surface  56  that is aligned in the same plane with the flat exterior surface  45  of handrail  40 . A second flat panel beam  57  connects the legs  46  and  47  of handrail  41  and spans the distance separating these legs. Beam  57  has a flat, smooth, outwardly facing exterior surface  58  that is aligned in the same plane with the flat exterior surface  49  of handrail  41 . A slight clearance space  59  separates the beams and steps. 
   A first integral post  60  is attached to first beam  55  and extends above beam  55 . A second integral post  61  is attached to second beam  57  and extends above beam  57 . The attached end  30  of the rear edge  15  of step  11  is pivotally connected at  62  to leg  42  above beam  55 . The attached end  29  of the front edge  14  of step  11  is pivotally connected at  63  to post  60  above beam  55 . The attached end  31  of the front edge  23  of step  27  is pivotally connected at  64  to the leg  43  of handrail  40 . The attached end  31  of the rear edge  24  of step  12  is pivotally connected at  65  to post  60  intermediate the ends of post  60 . 
   A first hollow cylindrical sleeve bushing  70  extends from an interior surface of the leg  46  toward the leg  47  above the beam  57 . A second hollow cylindrical sleeve bushing  71  extends from an inner surface of the leg  47  toward the leg  46  below the step  18 . A third hollow cylindrical sleeve bushing  72  extends from the second post  61  and is diametrically aligned with the bushing  70 . A fourth hollow cylindrical sleeve bushing  73  extends from the second post  61  and is diametrically aligned with the bushing  71 . The bushings  70  and  71  are secured in place by bolts that pass therethrough and are threaded into rivetnuts in the designated legs. The bushings  72  and  73  are held on the posts  60  and  61  by bolts that pass therethrough and are threaded into nuts. When the aid  10  is in its fully extended position, the unattached free end  22  of edge  15  of the step  18  is supported on the bushing  70  which is received in the notch  37 , the unattached free end  20  of edge  14  of the step  18  is supported on the bushing  72  which is received in the notch  36 , the unattached free end  31  of edge  24  of the step  27  is supported on the bushing  73  which is received in the notch  39 , and the unattached free end  29  of edge  23  of the step  27  is supported on the bushing  71  which is received in the notch  38 . 
   A first pivoting link  77  is pivotally connected at one end  78  to the outer side of a first rectangular prismatic support block  79  that is attached by bolts or welding (not shown) at a central location on the underside of step  11  adjacent to its rear edge  15 . The opposite end  80  of link  77  is pivotally attached to leg  46  adjacent the terminal end of the leg. A second pivoting link  81  is pivotally attached at one end  82  to a central portion of the flange  35  at the rear edge  24  of step  12  and at its opposite end  83  to a central portion of the flange  32  at the front edge  14  of step  11 . An integral tab  84  extends perpendicularly to link  81  toward step  11 . When the aid  10  is in its fully closed position, the tab  84  will bind against the edge  14  and prevent the step  12  from moving out of alignment past the step  18 . 
   A third pivoting link  88  is pivotally attached at one end  89  to the outer side of a second rectangular prismatic support block  85  that is attached by bolts or welding (not shown) at a central location on the underside of step  11  adjacent to its front edge  14 . The opposite end  90  of link  88  is pivotally attached to the post  61  below the bushing  73 . A first articulated pivoting link  91  has a long segment  92  and a short segment  93  that are pivotally connected to each other at one end at  94 . The opposite end  95  of the long segment  92  is pivotally attached to the leg  42  adjacent its terminal end. The long segment  92  of the first articulated link  91  and the link  71  are pivotally connected to each other at  96  intermediate their ends. The opposite end  97  of the short segment  93  is pivotally connected to the bushing  70 . A second pivoting articulated link  98  has a long segment  99  and a short segment  101  that are pivotally connected to each other at one end at  102 . The opposite end  103  of the long segment  99  is pivotally attached adjacent the bottom end of the first post  60 . The long segment  99  and the third link  88  are pivotally connected to each other at  104  intermediate their ends. The opposite end  105  of the short segment  101  is pivotally connected to the third bushing  72 . 
   A cylindrical stabilizer bar  106  has its opposite ends attached to the inner side of block  79  and the inner side of block  85  below step  11 . The effect of bar  106  is to interconnect the links  77 ,  81 ,  91  and  98 . This enables the bar to stabilize the aid  10  by preventing misalignment or wobbling of the links or steps. 
   When the aid  10  is in its folded position, as shown in  FIGS. 4 and 5 , all of the pivoting links, the bushings and the steps and the beams are confined within the inner edges or boundaries of the handrails  40  and  41 . There are no protruding bulges or sharp corners or edges that can mar other objects. The flat tread step surfaces  18  and  27 , the flat exterior beam surfaces  56  and  58 , and the flat exterior handrail surface  45  can all be aligned in the same plane. As shown in  FIG. 3 , these aligned planar surfaces occupy at least about 80% of the space circumscribed by the handrails. This relatively large, essentially continuous flat surface within the handrails enables the folded aid  10  to be easily slid on, against or between other flat or uneven surfaces for storing. This flat surface also is available as a firm horizontal supporting surface for holding or stacking heavy objects when the aid  10  is laid out horizontally. 
   While the present invention has been described with reference to particular embodiments, it is not intended to illustrate or describe all of the equivalent forms or ramifications thereof. Also, the words used are words of description rather than limitation, and various changes may be made without departing from the spirit or scope of the invention disclosed herein. It is intended that the appended claims cover all such changes as fall within the true spirit and scope of the invention.