Patent Publication Number: US-6988586-B1

Title: Apparatus with locking hinge convertible between creeper and stepladder configurations

Description:
This application is a continuation-in-part of my pending U.S. application Ser. No. 10/706,020, filed Nov. 12, 2003. 

   TECHNICAL FIELD 
   This invention relates to apparatus for supporting an individual and selectively alternatively employable as either a creeper or as a stepladder. 
   BACKGROUND OF THE INVENTION 
   Stepladders and creepers are well known devices. Conventionally, these devices are separate entities and are employed separately. This of course requires separate purchases. Furthermore, each device occupies its own storage space. 
   As will be seen below, the apparatus of the present invention incorporates platform portions hingedly interconnected to provide either a stepladder configuration or a creeper configuration. A search of the prior art located no such arrangement. There are, however, patents which show the general concept of folding creepers per se; namely, U.S. Pat. No. 6,095,532, issued Aug. 1, 2000, U.S. Pat. No. 5,947,489, issued Sep. 7, 1999, U.S. Pat. No. 6,059,298, issued May 9, 2000, U.S. Pat. No. 4,889,352, issued Dec. 26, 1989, and U.S. Pat. No. 2,611,417, issued Sep. 23, 1952. 
   The search also located U.S. Pat. No. 5,072,955, issued Dec. 7, 1991, relating to a mechanic&#39;s helper (not a creeper) and step platform, U.S. Pat. No. 6,105,719, issued Aug. 22, 2000, directed to a user-configurable mechanic&#39;s stool, and U.S. Patent Application Publication No. U.S. 2002/0125662, published Sep. 12, 2002. Articulated ladders enabling the ladders to fold and assume different configurations are also known, some of which utilize locking hinges generally. See the following patent publications: U.S. Pat. No. 4,925,329, issued May 15, 1990, U.S. Pat. No. 4,540,306, issued Sep. 10, 1985, U.S. Pat. No. 5,022,118, issued Jun. 11, 1991, U.S. Pat. No. 4,645,371, issued Feb. 24, 1987, U.S. Pat. No. 5,026,198, issued Jun. 25, 1991, U.S. Pat. No. 5,058,239, issued Oct. 22, 1991, U.S. Pat. No. 4,577,986, issued Mar. 25, 1986, U.S. Pat. No. 4,770,559, issued Sep. 13, 1988 and PCT Application No. WO 00/43627, published Jul. 27, 2000. However, such prior art articulated ladders are not convertible into creepers, nor is there any known prior art which incorporates the unique locking hinge structure disclosed herein in a convertible creeper/stepladder arrangement. 
   In summary, there is no teaching or suggestion in the prior art, whether taken alone or in combination, of the apparatus disclosed and claimed herein for supporting an individual and selectively alternatively employable as either a creeper or a stepladder. 
   DISCLOSURE OF INVENTION 
   The present invention relates to apparatus of unitary construction for supporting an individual and selectively alternatively employable as either a creeper or a stepladder. The apparatus incorporates a platform including a generally planar first platform portion and a generally planar second platform portion, each of the first and second platform portions having a top surface and a bottom surface and proximal and distal ends. 
   A pair of spaced locking hinges hingedly connect the proximal end of the first platform portion to the proximal end of the second platform portion. The first and second platform portions are selectively movable relative to one another about the at least one hinge to form either a creeper configuration wherein the first and second platform portions are substantially co-planar or a stepladder configuration wherein the first and second platform portions define an angle therebetween of less than 180 degrees and more than 0 degrees. 
   The locking hinges selectively alternatively lock the first and second platform portions against relative movement when in either said stepladder configuration or in said creeper configuration. Each locking hinge includes a first locking hinge member affixed to one of said first and second platform portions and a second locking hinge member affixed to the other of said first and second platform portions. Each locking hinge also includes a pivot element extending between and through the first and second locking hinge members. 
   The first and second locking hinge members are selectively pivotally movable relative to one another about the pivot element. Lock structure is employed for selectively alternatively locking the first and second locking hinge members together against pivotal movement about the pivot element when the first and second platform portions are in either the creeper configuration or the stepladder configuration. 
   The apparatus also includes wheels projecting downwardly from the bottom surfaces of the first and second platform portions for supporting the apparatus when the first and second platform portions are in the creeper configuration. At least one of the first and second platform portions defines foot holes for receiving the feet of an individual climbing the apparatus when the first and second platform portions are in the stepladder configuration. 
   Other features, advantages and objects of the present invention will become apparent with reference to the following description and accompanying drawings. 

   
     BRIEF DESCRIPTION OF DRAWINGS 
       FIG. 1  is a top, perspective view of the apparatus of the present invention configured as a creeper; 
       FIG. 2  is a greatly enlarged, perspective view of a locking hinge of the apparatus in the position assumed thereby when the apparatus is in a creeper configuration; 
       FIG. 3  is a top, perspective view of the apparatus when configured as a stepladder; 
       FIG. 4  is an exploded, perspective view of the locking hinge shown in  FIG. 2 ; 
       FIG. 5  is a top view of the locking hinge; 
       FIGS. 6 and 7  are side, elevational views of the locking hinge when the apparatus is configured as a creeper and showing lock structure thereof in two different positions; 
       FIG. 8  is a cross-sectional view taken along line  8 — 8  in  FIG. 5  showing components in the  FIG. 6  condition; 
       FIG. 9  is a view similar to  FIG. 8 , but showing components in the  FIG. 7  condition; 
       FIG. 10  is a view similar to  FIG. 2 , but showing the locking hinge locked in stepladder configuration; 
       FIG. 11  is a side, elevational view of the locking hinge in stepladder configuration; 
       FIG. 12  is a view similar to  FIGS. 8 and 9  showing lock structure components in stepladder configuration; and 
       FIGS. 13 and 14  are perspective views of selected portions of an alternative embodiment of the invention in alternative relative positions. 
   

   BEST MODE FOR CARRYING OUT THE INVENTION 
   Referring now to  FIGS. 1–12 , apparatus constructed in accordance with the teachings of the present invention is illustrated and is for the purpose of supporting an individual and selectively alternatively employable as either a creeper (also known as a mechanic&#39;s creeper) or a stepladder. 
   The apparatus includes a platform  10  including a generally planar platform portion  12  and a generally planar platform portion  14 . Platform portion  12  has a top surface  16  and platform potion  14  has a top surface  18 . The platform portions  12 ,  14  also have bottom surfaces. The platform portions may be formed of any suitable material, for example molded plastic or metal. The top surfaces  16 ,  18  are slightly concaved or dipped to provide comfort for an individual lying on the apparatus when in its creeper configuration, as will be described in more detail below. In the arrangement shown, the concavity of top surface  16  is slightly less than the concavity of top surface  18 . 
   The proximal ends  24 ,  26  of the platform portions  12 ,  14 , respectively, are hingedly connected by locking hinges  30  of identical construction but mirror images of one another. Locking hinges  30  enable the first and second platform portions to be releasably locked against relative movement when either in a stepladder configuration or in a creeper configuration. The locking hinges  30  will be described in detail below. 
   The platform portions are selectively movable relative to each other about the spaced locking hinges  30  to form either a creeper configuration (shown in  FIG. 1 ) wherein the platform portions  12 ,  14  are substantially co-planar or a stepladder configuration (shown in  FIG. 3 ) wherein the platform portions define an angle therebetween of less than 180 degrees and more than 0 degrees. 
   Casters including caster wheels  40  project downwardly from the bottom surfaces of the platform portions for supporting the apparatus when the platform portions are in the creeper configuration. In the arrangement illustrated, there are four caster wheels  40  projecting downwardly from each platform portion to provide stability. 
   The platform portions  12 ,  14  include a plurality of upwardly projecting fenders  42  defining fender interiors accommodating portions of the caster wheels  40 . The fenders further define side fender opening  44  which provide clearance for the casters to swing freely and also to provide access to the casters for replacement, repair, etc. In the arrangement illustrated, the casters are pivotally connected to the tops of the fenders by threaded connectors projecting through the fender tops. 
   The platform portion  12  defines elongated rectangular shaped foot holes  50  for receiving feet of an individual (not shown) climbing the apparatus when the platform portions are in the stepladder configuration. 
   Support surface engagement projections such as rubber pegs  52  project from the distal ends of the platform portions for engaging a floor or other support surface to support the apparatus when the platform portions are in the stepladder configuration to resist slippage of the apparatus on the support surface. A headrest  60  projects upwardly from platform portion  14  to add to the comfort of the user. 
   FIGS.  2  and  4 – 12  disclose one of the locking hinges  30 . Locking hinges  30  selectively alternatively lock the first and second platform portions against relative movement when either the stepladder configuration or in the creeper configuration. 
   Each locking hinge includes a locking hinge member  70  affixed to platform portion  12  by suitable mechanical fasteners and locking hinge member  72  similarly attached to platform portion  14 . 
   A pivot element in the form of pivot bolt  74  extends between and through locking hinge members  70 ,  72 , being secured in place by a nut. The locking hinge members  70 ,  72  are selectively pivotally movable relative to one another about pivot element  74 . FIGS.  2  and  5 – 9  show the locking hinge members  70 ,  72  in alignment, the configuration thereof when the apparatus is utilized as a creeper.  FIGS. 10–12 , on the other hand, show the locking hinge members  70 ,  72  angled relative to one another, the configuration thereof when the apparatus forms a stepladder. 
   Locking hinge member  72  includes a plate  76  having a circular-shaped outer peripheral wall and spaced, angled notches  78 ,  80  projecting inwardly from the outer peripheral wall. 
   Locking hinge member includes a projection  82  disposed side-by-side with the plate  76 . Projection  82  is bifurcated, i.e. the projection includes two spaced projection portions defining a gap receiving the plate. The projection portions are disposed on opposed sides of the plate to stabilize the plate against wobbling or sideways movement. 
   The locking hinge member  70  also includes lock structure for selectively alternatively locking hinge members  70 ,  72  together against pivotal movement about the pivot element  74  when the platform portions  12 ,  14  are either in the creeper configuration or the stepladder configuration. 
   The lock structure includes a lock element  88  pivotally mounted on platform portion  12  by a stud  90  comprising a component of locking hinge member  70 . A nut is threadedly secured to the distal end of stud  90 . A spacer (not shown) may be employed on the stud to maintain a predetermined distance between lock element  88  and platform portion  12 . 
   Lock element  88  has a closed distal end  92  in the form of a lock element end wall positioned at the end of a channel  94  which receives plate  76 . The closed distal end or wall  92  is selectively positionable in notches  78 ,  80 . 
   Biasing structure is associated with lock element  88  to bias closed distal end  92  towards the plate. More particularly, a manually engageable member  96  is affixed to lock element  88  and is utilized to pivot lock element  88  into and out of engagement with the plate  76  as desired. Once the closed distal end  92  exits the notches, pivoting of the locking hinge members is readily accomplished. Manual release of the member  96  allows entry of the closed distal end of the lock element into the notch with which it is aligned.  FIGS. 6–9  and  12  provide illustrations of this activity. 
   The lock element  88  is continuously biased so that the closed distal end thereof is urged toward the plate. Biasing is accomplished by means of a coil compression spring  98  disposed about a hollow boss  100  having a notch  102  at the upper end thereof. The notch accommodates member  96  at all times to provide stability thereto. 
     FIGS. 13 and 14  show another embodiment  10 A of the invention. In this embodiment platform portion  12 A has a bottom  120  and a top  122  defining a recess therebetween slidably accommodating a closure plate  124 . Closure plate  124  has closure plate openings  126  which conform to foot holes  50 A formed in the platform portion  12 A. The closure plate openings  126  communicate with foot hole openings  50 A when the apparatus is employed as a stepladder (the situation in  FIG. 13 ). 
   When the apparatus  10 A is to be used as a creeper, handles  128  are used to slide the closure plate  124  to the position shown in  FIG. 14  in which the foot holes  50 A are covered by the solid portion of the closure plate. This provides a more comfortable surface for supporting a person employing the apparatus in its creeper mode.