Abstract:
A collapsible loading ramp affixable to a raised surface in a non-permanent manner extending from the raised surface to the ground. The ramp is foldable by way of a hinge connecting the first ramp section to the lower ramp section. Rung units attach to the first and second ramp sections via posts and can be unattached to facilitate compact storage of the ramp pieces individually or in a compact box-like formation.

Description:
FIELD OF THE INVENTION  
         [0001]    This invention relates to a collapsible loading ramp suitable for gaining access to raised surfaces such as the bed of a pick-up truck or a raised ledge.  
         BACKGROUND  
         [0002]    Collapsible ramps provide a dual benefit. First, they provide a means of bridging the gap between a horizontal raised surface and the ground so that an object or vehicle can be moved along said ramp and be loaded on to the raised surface. Second, they can be folded or slideably compacted into themselves so as to allow for easy storage. The prior art includes several collapsible ramps that fixedly attach to a raised surface, most commonly the tailgate of a truck.  
           [0003]    Examples of prior art collapsible loading ramps are shown in Floe U.S. Pat. No. 5,538,308, Curtis U.S. Pat. No. 3,713,553 and Adaway U.S. Pat. No. 4,864,673.  
           [0004]    Floe discloses a portable ramp structure constructed by a plurality of pairs of support members having longitudinal channels for mounting a predetermined number of cross members therebetween. Retention chains with associated hooks removably attach the ramp structure to a transport vehicle.  
           [0005]    Curtis teaches a loading ramp that secures to a vertically swingable truck tail gate by mounting brackets. The ramp includes two sections hinged together to allow the ramp to fold so it can be stored in a compact form against the tailgate.  
           [0006]    Adaway discloses a collapsible ramp comprising an attachment frame, a foldable support structure mounted to the attachment frame by pivotable hinges and a telescoping deck structure of interconnected, essentially rectangular plates. The foldable support structure has longitudinal support members with foldable joints intermediate along the lengths of the members, and these members are pivotally connected to the hinge. The support members fold back on themselves to reduce the ramp to a collapsed state for storage purposes.  
         SUMMARY OF THE INVENTION  
         [0007]    The present invention provides a collapsible loading ramp which can be unassembled into pieces that can be stored conveniently. In its extended form, the ramp is removably attachable to a raised horizontal surface to provide access to the raised surface.  
           [0008]    The ramp is a collapsible folding ramp that includes two longitudinal support rails that are fixable to the edge of a raised horizontal surface against which the ramp is to be supported. The ramp further includes a plurality of support cross members that attach between the longitudinal support rails. In particular, the side rails include plurality of posts that extend upwardly therefrom and the surface panels include apertures at their side edges that engage over the posts. The panels and side rails may have several embodiments. Preferably, the panels include channels along their edges that overlie the side rails to distribute weight to the longitudinal support rails. The panel dimensions are such that they are easy to store when stacked one upon the other but are large enough to minimize the number of panels that must be mounted on the rails.  
           [0009]    The panels can be formed as rungs or alternately can have a plate surface. In one embodiment, the panels include rungs, as shown, but small plate members engage over the rungs. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]    [0010]FIG. 1 is one embodiment of the collapsible loading ramp shown mounted to the gate of a pickup truck.  
         [0011]    [0011]FIG. 2 shows the collapsible loading ramp of FIG. 1 in its extended position with perpendicular panels placed over the rungs and spaced a distance suitable to support the wheels of a vehicle to be driven up the loading ramp.  
         [0012]    [0012]FIG. 3 shows a front elevation view of a panel member.  
         [0013]    [0013]FIG. 4 shows a top plan view of a panel member.  
         [0014]    [0014]FIG. 5 shows a side view of a side rail in an extended position.  
         [0015]    [0015]FIG. 6 shows a side view of a side rail in a folded position.  
         [0016]    [0016]FIG. 7. shows a side elevation view of a side rail with a foot attachment at the lower end thereof, with the side rail shown in section.  
         [0017]    [0017]FIG. 8 shows an elevation view of the alternate means of fixing the ramp to the raised horizontal surface by way of straps.  
         [0018]    [0018]FIG. 9A shows an exploded view of a cross member.  
         [0019]    [0019]FIG. 9B shows an exploded view of another connection for a rung and side support.  
         [0020]    [0020]FIG. 10 shows a front elevation view of an assembled rung cross member.  
         [0021]    [0021]FIG. 11 shows a top plan view of an assembled rung cross member.  
         [0022]    [0022]FIG. 12 shows a front elevation view of a carrying case for the disassembled ramp.  
         [0023]    [0023]FIG. 13 shows a perspective view of the ramp pieces assembled as a box with a carrying handle.  
         [0024]    [0024]FIG. 14 shows a front elevation view of a plate member of FIG. 13.  
         [0025]    [0025]FIG. 15 shows a side elevation view of another ramp according to the present invention in its extended position, partially assembled and partially cut away.  
         [0026]    [0026]FIG. 16 shows a perspective view, partly in section, of a cross member useful in the embodiment of FIG. 15 on a rail.  
         [0027]    [0027]FIG. 17 shows a plurality of cross members of FIG. 15 in a stacked configuration. 
     
    
     DETAILED DESCRIPTION  
       [0028]    Referring now to FIG. 1 there is shown a collapsible loading ramp  11  mounted to the tailgate  12  of a pickup truck  10 . The ramp facilitates access to the bed of the truck via the tailgate. While a tailgate is shown, it is to be understood that the ramp can be used to provide access to any raised surface such as a porch, loading dock, etc.  
         [0029]    The collapsible ramp  11  includes a pair of foldable longitudinal support rails  18  and cross members  26  each including rungs  27  attached in groups and extending between a pair of side supports  22 . Cross-members  26  extend between the foldable longitudinal support rails and provide a surface for supporting movement over the ramp. Cross members  26  are mounted on support rails  18 , such that they generally extend at right angles to the long axis of the ramp. The ramp can be mounted onto the tailgate or raised surface in any desired manner. However, preferably any mounting arrangement engages the ramp to the tailgate  12  during use to prevent the ramp from working loose. In the illustrated embodiment, a mounting mechanism  14  is used which is attached at the end of each support rail  18 .  
         [0030]    While the embodiment of FIG. 1 shows the cross members formed as rungs, other cross members can be used such as solid plates or a combination thereof. For example, FIG. 2 shows the collapsible loading ramp  11  with plate members  30  fit over the rungs. Plate members  30  hook over the cross members  26  in a fixed but removable manner so as to be secure during use but easily adjustable. In the illustrated embodiment, the plate members  30  need only be slid along a rung in order to be moved to match the spacing of the tires of any vehicle that may be loaded via the ramp  11 . The plate members  30  also distribute the weight of an object being loaded evenly over a length of the rung surface. Each plate member  30  can be formed of a single length or multiple separate plate pieces, for example, an upper piece  30 B and a lower piece  30 A, as shown. The plate members each include a means for securing them to the cross members such as a hook, a clamp, a post or, as shown, ribs  31  forming a channel engageable over a rung. Plate members  30  are bent so as to be angled at one end  29 . The bent end of the plate member  29  can be upwardly positioned so as to connect with the tailgate  12  and provide an angled leadway to the tailgate  12 .  
         [0031]    [0031]FIGS. 5 and 6 show a longitudinal support rail  18  in greater detail. Longitudinal support rail  18  is formed of lower  18 A and upper  18 B portions foldably joined by a hinge  20 , which permits the rail to be folded (FIG. 6) and thereby facilitates storage. The hinge  20  is, in the illustrated embodiment, attached to the longitudinal support rail  18  by a bolted plate  38 . However, other hinge arrangements can be used as desired. A safety cable  36  is secured, as by use of rivets, to the bolted plate  38  of the hinge  20 . The safety cable  36  strengthens the hinged connection  20  and provides a secure connection between the upper  18 B and lower  18 A portions of the longitudinal support rail  18  so that the portions of the longitudinal support  18  will remain connected even in the event that the hinge breaks. A hinge secure extension  34  extends from the longitudinal support rail upper portion  18  and fits into an aperture in the longitudinal support rail lower portion  18 A when said rail is extended. Extension  34  serves to maintain the portions  18 A and  18 B in proper alignment and to distribute the stress at the hinge over a greater area.  
         [0032]    Releasable mounting mechanism  14  includes a mounting strap  16  extending from the end of each longitudinal support rail  18 . The mounting mechanism  14 , as shown, can also include a pin  14  insertable through an aperture  16   a  in each mounting strap  16 . The releasable mounting mechanism operates by securing to a raised surface which includes apertures for accepting pins  14 . In particular, the releasable mounting mechanism is operated by placing mounting straps  16  onto a raised surface, such as a tailgate or mounting ledge, and aligning apertures  16   a  with apertures in the raised surface. Pin  14  is then fit through the aperture  16   a  in the mounting strap  16  and. through the aperture in the tailgate or mounting ledge. Once inserted entirely through the aligned apertures a removable cotter pin  32  already fit through an aperture in the pin  14  acts to hold the pin  14  in place. Various other mounting means can also be utilized to mount the ramp onto a tailgate or mounting edge, such as adhering a non-slip material to the base of the mounting strap  16  so that when it is placed on the tailgate  12  the ramp is supported.  
         [0033]    [0033]FIG. 2 shows another type of mounting means employing a hooked flexible strap  41  (FIG. 8), which may be attached to the mounting strap  16  by fitting the pin  14  through both an eye  40  in the hooked strap  40  and the aperture  16   a  in the mounting strap and affixing cotter pin  32  through pin  14 . The pin  14  should be inserted through the aperture  16   a  in the mounting strap  16  upside down so that the end of the pin and the cotter pin point upwards and neither can damage the surface of the tailgate  12 . Once attached to mounting strap  16 , hooked strap  41  can be extended to secure the ramp. In particular, hooked end  42  of the strap can be engaged over an edge or around a support member and hooked onto the strap to support the ramp. In FIG. 2, one strap  41  is shown with its hooked end  42  engaged over an edge of the tailgate and the other strap is attached to mounting strap  16  but not yet engaged over an anchor point.  
         [0034]    The support rails  18  can be set at their lower end directly on the lower surface. Alternately, as shown in FIG. 7, a foot attachment  43  can be mounted to the lower portion of the longitudinal support rail  18 . A flat foot side panel  44  is affixed parallel to the longitudinal support rail lower portion  18   b  via a pin  46  which fits through an aperture in the foot side panel and an alignable aperture in the longitudinal support rail  18 A. A perpendicular attachment extends from the foot side panel  44  to the foot base  48 . A non-slip material  49  may be attached to the underside of the foot base  48 .  
         [0035]    For attachment of the cross members  26 , longitudinal support rails include a plurality of posts  24  fixedly attached to their upper surfaces. Posts  24  are sized to fit though apertures formed on the cross members  26 . Preferably, the posts  24  are sized to extend upwardly through apertures  28  but are short enough such that they do not interfere with passage over the ramp. Posts  24  are preferably angled towards to the top of the ramp so that the cross members  26 , can engage them and do not easily become disengaged from the rails when engaged over the posts  24 .  
         [0036]    One embodiment of a cross member  26  is shown in exploded configuration in FIG. 9 and in assembled form in FIGS. 10 and 11. Cross member  26  includes a pair of side supports  22  and three rungs  27  extending there between. It is to be understood that, while three rungs are shown, any number of rungs can be used on each cross member. Side supports  22  are formed as channels sized to fit over longitudinal support rails  18 . Each side support  22  includes a form, such as an aperture  28 , as shown, for securing over a post  24  on the longitudinal support rail over which it is selected to fit. As will be appreciated, the positioning, size, and number of forms on a side support  22  will be determined by the placement, spacing and size of the posts  24  on the longitudinal support rails with which the cross members are to be used.  
         [0037]    The rungs are attached to the side supports such that they can withstand application of a desired weight, such as a small tractor, without failing. Preferably, the rungs are constructed to permit a degree of flex or pivot movement between the rungs and the side supports such that they can withstand some offset between longitudinal side rails  18  while the side supports remain firmly in engagement with the posts on the side rails.  
         [0038]    In the illustrated embodiment, to assemble the cross members rungs  27  having hollow interiors can be used. A fixed post  62  and a post providing for pivotal attachment of the rung  50 , are attached to the each inner longitudinal edge of a side support  22 . Fixed posts  62  are substantially rigidly attached to side supports  22 , as by a means such as welding and thereby cause the rungs to be rigidly attached to the side supports when the rungs are secured into the fixed posts. Posts  50  can be attached to the side supports  22  by a variety of means. FIG. 9A shows rectangular posts  50  that are attached to a panel via a bolt  68  and secured with a nut  70 , such that posts  50  can pivot about the long axis of the bolt. As such, pivotal movement is permitted, as indicated by arrows a, between the rungs and the side supports, when the rungs are mounted onto the posts. FIG. 9B shows an alternative means of achieving pivotal connections between the rungs and the side supports wherein round posts  50   a  are fixedly attached, by a means such as welding, to the side supports  22 .  
         [0039]    Fixed posts  62  and posts  50  are sized so as to fit within the hollow interior of a rung  27 . In assembly, a single rung  27  is secured with a fixed post  62  at one end and a post  50  at the other end. Fixed posts  62  and posts  50  will be positioned so as to alternate along the side support  22 .  
         [0040]    A method of attaching the rungs to the fixed and posts is shown in FIG. 9A by which an aperture  64  and  52  extends through the upper and lower faces of the posts on one end of the rung and an aperture  66  and  58  extends through the upper and lower faces of the rung  27  near the opposite end of the rung  27 . When the rung  27  and the posts are fit together the apertures  64  and  52  in the posts and the rung line up to form a single hole into which a bolt  54  or  57  can be inserted and locked therein by a nut  56  or  57   a , so as to attach the cross member  60  to the post.  
         [0041]    Round posts  50   a  as shown in FIG. 9B are fitted into the open end of the rung  27 . Aperture  58  in the rung  27  is aligned with a slot  55  in the post  50   a  so that bolt  54  is inserted into the aperture and through the slot  55  and locked by a nut  56  so as to attach the cross member to the post. Slot  55  therefore permits sliding movement of the bolt and therefore, pivotal movement of the rung relative to the side support, without a simpler arrangement than that shown in FIG. 9A.  
         [0042]    Of course, fasteners, such as rivets or pins, other than bolts  54 ,  57  can be used, as desired.  
         [0043]    The ramp is foldable to facilitate storage thereof. FIGS. 13 and 14 show embodiments of means for storing the ramp when it is not in use. In particular, FIG. 13 shows a carrying case  80  in which the individual unassembled pieces of the ramp, including rails  18  and cross members  26 , can be packed. The clasps  82  on the carrying case  80  keep the case closed and the handle  84  allows for easy transportation of the stored ramp. Carrying case  80  is sized to accommodate all of the pieces of the ramp, with the rails folded about hinge  20  and the cross members  26  removed from posts  24  and stacked one upon the other.  
         [0044]    [0044]FIG. 14 shows, in partial exploded configuration, a stacked assembly of ramp pieces, including support rails  18 , cross members  26  and panels  30  formed into a box-shaped structure for transport. In this assembly, cross members  26  are stacked one upon the other with side supports  22  aligned within the stack. Support rails  18  folded around the hinge fit between the cross members in the stack. Pins  90  are inserted through aligned apertures  28  in the stacked cross members. A lock clamp  92 , or other locking means such as a spring biased detent, is provided in association with each pin  90  to releasably lock the pins through the apertures. In this embodiment, plate members  30 C are placed on the top and the bottom of the stacked cross members  26  to form a solid outer face for the box structure. Plate members  30 C are formed and sized to fit between side supports  22  with flanged ends  94  fitting down between adjacent rungs  27 . Flanged ends  94  each include an opening  96 , which can be engaged over pin  98  to secure the plates in place. A handle piece  99  can be attached to a cross member to allow the box structure to be easily transported.  
         [0045]    In this embodiment, to facilitate use of the plate members, slots  100  are formed to accommodate flanged end  94  of the adjacent plate, when the plates are mounted on the assembled ramp.  
         [0046]    The individual pieces of the ramp when unassembled can be stored in one of the manners described or in other ways such as each piece being separate from the other pieces.  
         [0047]    One person can easily collapse and extend the ramp making it possible to load or unload a machine quickly and efficiently.  
         [0048]    Referring to FIGS.  15  to  17 , there is shown another ramp embodiment according to the present invention. The ramp includes side rails  118  (only one can be seen as one is disposed behind the other) and cross members  126  (only one is shown already mounted on the rails).  
         [0049]    The side rails are formed as two parts including a first member  118 A and a channel member  118 B connected and foldable at a hinge formed by hinge pin  120 . The hinge includes a shock absorbing member which can be, for example, a rubber insert  121 , as shown or a spring that acts against compression. The shock absorbing member acts between the rail parts to bias them into a slightly folded configuration. When a load is applied to the ramp, the shock absorbers will ease rotation about the hinge and when sufficient load is applied to overcome the tension in the shock absorber, the rail parts will pivot to further straighten and extend the rail. The shock absorber provides the side rails with a slight arch, which facilitates loading of mower decks and protects the hinge components to reduce fatigue and sagging at the hinge.  
         [0050]    A safety pin or detent  117  arrangement can be provided to lock the side rails into an extended position. Any such arrangement should be selected to permit limited movement about the hinge pin, as will be needed to gain the benefit of the shock absorber.  
         [0051]    The formation of the rails as a first member and a channel member permits that when the parts are folded first member  118 A can fit into the hollow inner space  123  of the channel member. This reduces the overall folded size of the rails over a folding rail arrangement of FIG. 6. First member  118 A can be formed in any way, such as by use of a hollow tubular, a solid rod or a channel.  
         [0052]    First member  118 A and channel member  118 B of the side rails can conveniently be formed by extrusion, for example of aluminum. As such, returns  119  can be formed in the channel member to facilitate securing mounting strap  116 .  
         [0053]    Rails  118  in this embodiment include posts  124  for engaging cross members  126 . Posts  124  each include an angled head  125  under which the cross member to be engaged thereon can slid to be locked against lifting thereoff, as will be described in greater detail hereinbelow.  
         [0054]    Cross members  126  are formed to engage over posts  124  and to extend between side rails  118 . Cross members  126  each include side supports  122  and rungs  127  extending therebetween. In this illustrated embodiment, side supports  122  are formed to be reversibly mountable with either first facing side  122 A or second facing side  122 B fitting over side rails. In particular, the side supports are formed with longitudinal recesses between raised edges  129  on both sides  122 A and  122 B to fit over the side rails. This facilitates mounting of the cross members on the rails, avoiding a situation wherein the cross members are incorrectly mounted with their wrong side up on the rails.  
         [0055]    Side supports  122  include slots  128  sized to permit passage therethrough of the angled portion  125 . However, the side supports are of a thickness to slide under the angled portions to be locked against lifting off the posts.  
         [0056]    Rungs  127  are secured between side supports  122  by any durable means such as by welding, bolting or through the use of connectors  162  therebetween which, as discussed in previous embodiments, can be formed to permit some flex between the rungs and the side supports.  
         [0057]    Note that the side supports have a height that permits compact stacking for storage. In particular, the height of the side members is less than, and preferably about half, that of the rails. With reference to FIG. 17, this permits two cross members  126 ′,  126 ″ to be stacked with their side supports  122 ′,  122 ″, respectively, resting directly one upon the other and their rungs  136 ′,  136 ″ offset between adjacent cross members in the stack.  
         [0058]    While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only preferred embodiments have been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected.