Abstract:
An extendable-retractable step system for a recreational vehicle (RV) has a step tread attached to a slider rod via side arms that include one or more locking tabs, and includes a pair of end plates having tab-receiving slots and notched slider slots that define extended and retracted positions. A method of assembling the step system and mounting same to a vehicle frame without using specially adapted tools includes the steps of mounting one of the end plates to the vehicle frame, inserting the ends of the slider rod into the slider slots, mounting the other end plate to the vehicle frame, and resting the locking tabs in the tab-receiving slots.

Description:
FIELD OF THE PRESENT INVENTION 
     The present invention relates to a step for a recreational vehicle and, more particularly, to a retractable-extendable step permitting ingress into and egress from a recreational vehicle and a method of assembling same. 
     BACKGROUND OF THE PRESENT INVENTION 
     Recreational vehicles (RVs) are a well known part of American life and come in many different configurations. Some are stand-alone units, possessing all the elements of an ordinary vehicle in addition to a living and sleeping quarters. Others must be towed behind a conventional vehicle, usually by means of a tongue-and-ball system, a hitch system, or a fifth-wheel and kingpin system. In any event, however, all RVs are characterized by their dual nature—on one hand, a living and sleeping quarters; on the other, a moving vehicle. 
     The use of the RV as a living and sleeping quarters is much enhanced by facilitating easy ingress into and egress from the interior of the RV when it is stationary. Because the floor of the RV may be quite a distance (more than a usual stepping height of 8 to 12 inches) from the ground outside the RV, a step may be provided at a level intermediate the ground and the door sill in order to ease ingress and egress. Such a step is typically mounted to the RV frame for stability and is best provided at a point somewhat outside the vertical plane formed by the side of the RV, so that a person exiting the RV may step through the door while facing forward. 
     However, a step fixed at a location outside the vertical plane formed by the side of the RV poses an obvious hazard when the RV is in motion, such as on a highway. For that reason, it is helpful to have a step that may be extended when the vehicle is stationary, and retracted when the vehicle is in motion. Various steps capable of this function have been proposed. For instance, Wonigar, U.S. Pat. No. 3,955,827, discloses a stowable step for vehicles, the stowing action of which is accomplished by a system of slotted supports and links which work to fold the step under the vehicle. The system of U.S. Pat. No. 3,955,827, however, is complicated, using many moving parts to accomplish this stowing function. Other typical systems are likewise complicated. They may require specialized tools to assemble or attach them to the frame. They may be sufficiently complicated that it is practical only to assemble the entire system at the point of manufacture, which leads to increased costs for shipping the unit or for attaching it to the RV frame. Additionally, they may be susceptible to breakdown or malfunction because of the failure of one of many parts. 
     A subsidiary problem associated with the retracting and extending function of the step is the need to keep the step in the desired position while maintaining ease of movement between the retracted and extended positions when such movement is desired. For instance, when the RV is in motion, bumps or sharp turns in the roadway might induce the step to move unexpectedly from the retracted position, creating a hazard. Alternatively, when the RV is stationary, a person stepping onto the step might be injured if the stepping force caused the step to move unexpectedly toward the retracted position. 
     It is therefore desirable to have a step that includes relatively few moving parts, that may be assembled remotely from the point of manufacture and assembled and attached to the frame without the use of specially adapted tools, and which is capable of being placed and maintained in either a retracted or extended position. 
     OBJECT AND SUMMARY OF THE PRESENT INVENTION 
     It is accordingly an object of the present invention to provide a step system of relatively simple design, which is mountable to an RV frame and is retractable and extendable as well as able to be maintained or locked in a retracted or extended position. It is a further object of the present invention to provide such a step with parts in disassembled relation, in order to minimize shipping and inventory costs, but which may be assembled without using complicated procedures or specially adapted tools. 
     It is yet a further object of the invention to provide a method of assembling a step for a recreational vehicle and mounting the step to a vehicle frame, the method being accomplished without specially adapted tools and resulting in a step that is securely mounted to the frame and movable between and lockable at retracted and extended positions. 
     Briefly summarized, the present invention includes a step mountable to an RV frame, generally including a step tread unit with a slider rod and at least one locking tab, and a pair of end plates, each slotted to receive an end of the slider rod and to receive a locking tab. The present invention further includes a method of assembling a step for an RV without using specially adapted tools, generally including the steps of mounting one of the end plates to the RV frame, inserting opposite ends of the slider rod into slider slots in the end plates, and then mounting the second end plate to the RV frame. The method of the present invention is capable of being performed by persons of limited mechanical skill and training possessing only ordinary tools, enabling it to be practiced remotely from the point of manufacture of the step. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Further features, embodiments, and advantages of the present invention will become apparent from the following detailed description with reference to the drawings, wherein: 
     FIG. 1 is a perspective view of an assembled step system in the retracted position; 
     FIG. 2 is a perspective view of an assembled step system in the extended position; 
     FIG. 3 is a perspective view of the components of the step system in exploded relation; 
     FIG. 4 is a partial perspective view of an assembled step system mounted to a recreational vehicle frame; and 
     FIGS. 5A-5D illustrate the sequence of steps of the method of the present invention. 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Referring now to the drawings, a first preferred embodiment of the present invention is shown in a retracted position in FIG.  1  and in an extended position in FIG.  2 . The step system of FIG. 1 has a step tread unit  10 , which comprises step tread  11 , upon which are affixed one or more strips  12 , which improve the safety or comfort of use of the step. Strips  12  may be formed generally of a grit-type material fused to a backing, which may be attached to step tread  11  by means of an adhesive or by any other suitable means. Alternatively, strips  12  may be formed of rubber, plastic, or a padding material. Step tread unit  10  includes a pair of side arms  14  which extend downwardly and rearwardly from opposite ends of step tread  11 . Side arms  14  may be formed as a unitary part of step tread  11 , or they may be formed from a different piece of material and attached to step tread  11  by means of rivets  16 , welding (not shown), nuts and bolts (not shown), or any other suitable attaching means. The rear ends of side arms  14  are angled upward and are formed with holes  19  to receive slider rod  20 . Slider rod  20  extends transversely behind step tread unit  10  beyond side arms  14 . Left and right end plates  22  each have a top flange  24  extending orthogonally to the main, vertical portion of the end plate  22 . Each top flange  24  has one or more holes  43 A for attaching end plate  22  to a vehicle frame  40  (FIGS.  4  and  5 B- 5 D), the attachment being accomplished using nuts and bolts, rivets, or other suitable means as more fully described hereinafter. Each end plate  22  is formed with a slider slot  28  adapted to receive an end of slider rod  20 , which extends therethrough. Slider slot  28  has a main elongate horizontal portion  32  defining a path of travel of slider rod  20  between retracted and extended positions, which are defined by a downwardly extending rear notch  30 A and a downwardly extending front notch  30 B at opposite ends of the main elongate horizontal portion  32 . 
     FIG. 2 illustrates a step system as in FIG. 1 in an extended position. Step tread unit  10  has been lifted so that slider rod  20  exits rear notch  30 A, slides along elongate portion  32 , and comes to rest in front notch  30 B, the step system thereby being in the extended position. Visible in this extended position are several features of a preferred embodiment not visible in FIG. 1. A pair of locking tabs  34 A, 34 B extend downwardly from the bottom edge of each side arm  14 . Each end plate  22  has an orthogonal bottom flange  26  extending under the path of motion of step tread unit  10 . Each bottom flange  26  has tab-receiving slots  38 A, 38 B corresponding in number and in spacing to locking tabs  34 A, 34 B, which are adapted to engage with tab-receiving slots  38 A, 38 B when the step system is in the retracted position in order to reduce the likelihood of unwanted movement of the step system out of the retracted position. Each locking tab  34 A is further disposed so as to abut the forward edge of the respective bottom flange  26  when the step system is in the extended position and slider rod  20  is received in front notch  30 B. The abutment of locking tab  34 A with bottom flange  26 , in combination with the weight of the step tread unit urging slider rod  20  to seat in front notch  30 B and the downward additional pressure of a person (not shown) stepping on step tread unit  10 , prevents unwanted movement of the step system out of the extended position. 
     Referring now to FIG. 3, the step system of FIG. 1 is shown with the members thereof in exploded relation. Step tread  11  is provided with pair of strips  12  for increasing the safety or comfort of use of the step system. A pair of side arms  14  are connectable to step tread  11  by means of rivets  16  through holes  18 A,  18 B and extend under and behind step tread  11 . Side arms  14  are each provided with a pair of locking tabs  34 A, 34 B and angle behind step tread  11  to receive, through holes  19 , slider rod  20 . Slider rod  20  is of sufficient length to extend beyond side arms  14  through slider slots  28  in end plates  22 . Slider slots  28  each comprise an elongate portion  32 , defining a traveling path of slider rod  20  between retracted and extended positions, intermediate a pair of notches  30 A, 30 B. End plates  22  are each further provided with a top flange  24  and a bottom flange  36 . Top flange  24  is formed with holes  43 A through which end plate  22  may be attached to the vehicle frame, as explained below. Bottom flange  36  is formed with tab-receiving slots  38 A, 38 B corresponding to locking tabs  34 A, 34 B. Notches  30 A, 30 B, locking tabs  34 A, 34 B, and tab-receiving slots  38 A, 38 B are disposed such that when slider rod  20  is in notch  30 , locking tabs  34 A, 34 B engage with tab-receiving slots  38 A, 38 B to prevent unwanted motion of the step system out of the retracted position. Notch  30 B, locking tab  34 A, and bottom flange  36  are further disposed such that when slider rod  20  is engaged with notch  30 B, locking tab  34 A abuts the forward edge of bottom flange  36  so as to prevent unwanted motion of the step system out of the extended position. 
     As can be seen in FIG. 3, each bottom flange is provided with two tab-receiving slots  38 A, 38 B and each side arm  14  is provided with two locking tabs  34 A, 34 B. However, it is possible to vary the number of locking tabs  34  and tab-receiving slots  38  according to the desired degree of system stability. For instance, each side arm  14  could be provided with one, three, or more locking tabs  34  and each bottom flange  36  could be provided with a corresponding number of tab-receiving slots  38 . Alternatively, only one of the side arms  14 . and one of the bottom flanges  36  could be provided with locking tabs and tab-receiving slots. It will be apparent to one skilled in the art to which the present invention relates that the particular number of locking tabs and tab-receiving slots is less important than the fact of their presence in the present invention. 
     As can also be seen in FIG. 3, end plates  22 , though oriented opposite from each other when the step system is assembled, are in a preferred embodiment identical to each other in the placement of top and bottom flanges  24 , holes  43 A, slider slots  28 , notches  30 A, 30 B, elongate portions  32 , and tab-receiving slots  38 A, 38 B. Such a design choice may yield a substantial advantage in reducing design, production, and shipping cost. 
     Referring now to FIG. 4, the step system of FIGS. 1-3 is shown in fully assembled relation, attached to frame  40  (indicated by dashed lines) of recreational vehicle  42  by means of bolts  44  and nuts  46  and placed in the retracted position. 
     It will be apparent to those skilled in the art that the simplicity of the step system of the present invention makes it suitable to a particular method of assembling the step system and attaching the step system to the frame of a recreational vehicle, the method forming part of the present invention. Referring now to FIGS. 5A-5D, the steps of the method of assembling and attaching a step to a recreational vehicle are shown in particular detail. FIG. 5A shows a step for a recreational vehicle, comprising in disassembled relation left and right end plates  22 A, 22 B, each formed with a slider slot  28  and at least one tab-receiving slot  38 , and a step tread unit  10 , generally comprising a step tread  11 , at least one locking tab  34 , and a slider rod  20  attached thereto. FIG. 5B shows left end plate  22 A being initially mounted to vehicle frame  40  by placing bolts  44  through holes  43 A,  43 B and securing with nuts  46 . FIG. 5C shows one end of slider rod  20  inserted through right end plate  22 B, and the opposite end of slider rod  20  is inserted through left end plate  22 A. FIG. 5D shows right end plate  22 B mounted to vehicle frame  40  by placing bolts  44  through holes  26 A, 26 B (best seen in FIG. 5C) and securing with nuts  46 . Locking tabs  34  (best seen in FIG. 5A) are then rested in tab-receiving slots  38 . As can be seen most clearly in FIGS. 5B-5D, the step system is, by the method of the present invention, mounted at a point of ingress into and egress from a recreational vehicle, and the assembly and mounting of the step system may be accomplished substantially simultaneously. 
     It will be apparent to those skilled in the art to which the present invention relates that the step system and method of assembling and attaching same to an RV frame are suited to a number of particular commercial advantages. First, the relative simplicity of the design reduces the costs of producing and servicing the step system. Second, providing the components of the step system in disassembled or partially assembled relation enables like individual components to be shipped together, decreasing the amount of packing space that would be wasted if the irregularly shaped step system were shipped fully assembled. Third, because the step system may be assembled and attached without the use of specialized tools, using ordinary means of attachment, it is possible for the system to be assembled and attached at points remote from the point of manufacture, making the step system suitable for offering by RV dealers or manufacturers as an optional feature or as an after-market item available to be purchased and installed by individual owners of RVs. 
     In view of the aforesaid written description of the present invention, it will be readily understood by those persons skilled in the art that the present invention is susceptible of broad utility and application. Many embodiments and adaptations of the present invention other than those herein described, as well as many variations, modifications, and equivalent arrangements, will be apparent from or reasonably suggested by the present invention and the foregoing description thereof, without departing from the substance or scope of the present invention. Accordingly, while the present invention has been described herein in detail in relation to preferred embodiments, it is to be understood that this disclosure is only illustrative and exemplary of the present invention and is made merely for purposes of providing a full and enabling disclosure of the invention. The foregoing disclosure is not intended nor is to be construed to limit the present invention or otherwise to exclude any such other embodiments, adaptations, variations, modifications and equivalent arrangements, the present invention being limited only by the claims appended hereto and the equivalents thereof.