US 20030051299 A1
A set of steps where each step is hinged to left and right stringers is disclosed. To convert the steps to a ramp, the bottom step is lifted, inverted, and laid down so that the underside of the tread of the step is exposed. Each step is lifted and laid down in the manner described above so that a ramp is formed. The top step has an additional board hinged to the underside of the tread. When the top step is inverted and laid down, the additional board is opened and laid down. The additional board acts as an extension so that the ramp reaches the floor or elevated surface to which the steps are attached. The top free edge of the additional board and the forwardmost free edge of the lower step are chamfered to provide smooth transitions from the ground to the ramp and from the ramp the elevated surface.
1. A convertible step and ramp combination comprising:
a plurality of steps including a top step and a bottom step wherein each of said steps has a top tread side and a ramp underside;
left and right stringers, and
hinge means pivotally securing each of said steps to said left and right stringers adjacent their forward edges,
whereby each of said steps can be inverted by pivoting the same about its respective hinge means to expose its ramp underside so as to form a continuous inclined surface.
2. The convertible step and ramp combination of
3. The convertible step and ramp combination of
4. The convertible step and ramp combination of
5. The convertible step and ramp combination of
 The present invention is directed toward a set of convertible steps and more particularly, toward a set of steps which converts to a ramp.
 Transporting people or freight in wheeled vehicles between various elevations is a common occurrence. Frequently, ramps are used to transport wheeled vehicles. However, ramps are usually not very aesthetically pleasing especially when they are located outside of a home. Furthermore, a ramp is not always necessary and steps may still be needed or desired. Therefore, a need arises to easily convert a set of steps to a ramp and vice versa.
 For example, U.S. Pat. No. 5,634,440 to Mogck discloses a step and ramp combination which includes a frame and steps. The steps have hangers attached thereto and rest on rods extending between the frame. In order to convert the steps to a ramp, the steps are removed and then placed at an angle by repositioning the hangers. This system, however, is intended to allow pets to climb to various elevated places and is portable. It is not intended to be incorporated into a set of steps attached to a building nor is it intended to be used by humans.
 Also, U.S. Pat. No. 4,539,781 to McCoy discloses a set of stairs which may be converted to a ramp and includes a plurality of stairway treads and a plurality of stairway risers where the treads and risers are hinged together in alternating sequence so that the stairway may be expanded into a ramp. A power means operates a mechanism to change the stairway to a ramp or the reverse. This device, however, is rather complicated and requires a great deal of machinery.
 A need exists for a permanent construction for converting a set of steps into a ramp and vice versa which is inexpensive and which is simple to use.
 The present invention is designed to overcome the deficiencies of the prior art discussed above. It is an object of the present invention to provide a set of steps which is easily and quickly converted to a ramp.
 It is another object of the present invention to provide a permanent structure which may be constructed on the outside of a building or home.
 It is still another object of the present invention to provide a prefabricated structure which may be easily transported to and attached to the outside of a building or home to become a permanent part thereof.
 In accordance with the illustrative embodiments demonstrating features and advantages of the present invention, there is provided a set of steps which converts to a ramp. Each step is hinged to left and right stringers. To convert the steps to a ramp, the bottom step is lifted, inverted, and laid down so that the bottom or underneath of the tread of the step is exposed. Each step is lifted and laid down in the manner described above so that a ramp is formed. The top step has an additional board hinged to the bottom of the tread. When the top step is inverted and laid down, the additional board is opened and laid down. The additional board acts as an extension so that the ramp reaches the floor or elevated surface to which the steps are attached.
 Other objects, features, and advantages of the invention will be readily apparent from the following detailed description of a preferred embodiment thereof taken in conjunction with the drawings.
 For the purpose of illustrating the invention, there is shown in the accompanying drawings one form which is presently preferred; it being understood that the invention is not intended to be limited to the precise arrangements and instrumentalities shown.
FIG. 1 is a front perspective view of the steps of the present invention attached to an elevated surface;
FIG. 2 is a front perspective view of the steps of the present invention converted to a ramp while attached to an elevated surface;
FIG. 3 is a right side elevational view of the steps of the present invention attached to an elevated surface;
FIG. 4 is a view similar to FIG. 3 detailing the initial process of converting the steps of the present invention to a ramp;
FIG. 5 is an enlarged view of section 5 of FIG. 4 with a portion broken away to illustrate an attaching means for the upper step;
FIG. 6 is a right side elevational view of FIG. 2 of the steps of the present invention converted to a ramp;
FIG. 7 is an enlarged cross-sectional view taken through section 7 of FIG. 6; and
FIG. 8 is an enlarged cross-sectional view taken through section 8 of FIG. 6.
 Referring now to the drawings in detail wherein like reference numerals have been used throughout the various figures to designate like elements, there is shown in FIG. 1 a set of convertible steps constructed in accordance with the principles of the present invention and designated generally as 10.
 The present invention essentially includes a set of steps which converts to a ramp. Each step 12, 14, and 16 is hinged adjacent its forward edge to right and left stringers 18 and 20 via hinges 22 a, 22 b, 24 a, 24 b, 26 a, and 26 b, respectively. (See FIGS. 1 and 2.) It should be realized that while only three steps are illustrated any number of steps may be used. Each step above the bottom i.e. top step 12 and step 14, has two cut-outs or slots 28 a, 28 b, 30 a, and 30 b, respectively, formed on the rear edge of the tread opposite the hinges. (See FIG. 1.) This allows the steps to interact with the stringers in a manner that will be described in more detail below.
 The top step 12 has an additional panel or board 32 hinged to the underside 34 of the step 12 via hinges 36 a and 36 b. (See FIGS. 2, 4 and 5.) The board 32 and the underside 34 of the top step 12 have complimentary securing or attaching means so that the board 32 is normally held to the top step 12. (See FIG. 5.) For example, the securing means may be sockets 38a and 38b formed in the bottom side 34 of the step 12 and pins 40 a and 40 b formed on the board 32 which fit into the sockets 38 a and 38 b, respectively. (See FIGS. 2 and 5.) The purpose of this board 32 will be discussed in greater detail below.
 To convert the steps to a ramp, the bottom step 16 is lifted, flipped over or inverted, and laid down so that the underside 42 of the tread 44 of the bottom step 16 is exposed. (See FIGS. 6 and 7.) The leading edge of the tread of the bottom step 16 is tapered or chamfered such as shown at 46 so that a smooth transition is created between the ground surface 48 and the bottom of the ramp. (See FIG. 2.) Each step is lifted and laid down in turn in the manner described above and independently of the other steps so that a ramp is formed. (See FIG. 4.)
 As shown best in FIGS. 6 an 7, the slots 28 a, 28 b, 30 a and 30 b formed in the tread surfaces allow the leading edges of the ramp sections to fit over the left and right stringers 18 and 20. This permits the leading edges of the ramp sections to be slightly lower so as to allow for proper alignment with the next section below.
 When the top step 12 is flipped over and laid down, the additional board 32 is released from the securing means of the step 12 and is rotated clockwise as shown in FIG. 5 about hinges 36 a and 36 b. The additional board 32 acts as an extension so that the ramp reaches the floor or elevated surface 50 to which the stairs are attached. (See FIG. 2.) The leading edge 52 of the additional board 32 is chamfered in complimentary fashion with the edge 54 of the elevated surface 50 in order to provide a smooth transition between the top of the ramp and the elevated surface 50. (See FIG. 8.)
 In order to restore the ramp to a set of steps, the process is simply reversed. That is, the top step 12 is lifted upwardly and the additional board 32 is removed from its engagement with the elevated surface 50. The additional board 32 is secured to the underside 34 of the top step 12 and together, the step and board are replaced on the stringers 18 and 20 so that the top side 56 of the tread is exposed. Similarly, the succeeding steps are lifted and flipped back into position on the stringers with the top side of each tread exposed.
 The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof and accordingly, reference should be made to the appended claims rather than to the foregoing specification as indicating the scope of the invention.