Abstract:
A system for attachment to a child&#39;s crib combining a side rail and a ramp structure that serve to prevent the child from rolling out during sleep, and at the same time provide a means for the child to climb or crawl into or out from the crib. Components include a side rail fixed to the crib at each end by removable straps or the like, and rigidly connected to a pair of legs that slide between the mattress and box spring of the crib. A generally larger ramp component extends pivotally outward and downward from the side rail component to a point in contact with the floor. Embodiments include multiple hinged components within the ramp system to allow alternate positioning of the ramp (in whole or in parts) in an extended or a collapsed configuration.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates generally to furniture and furnishings for baby nurseries and child bedrooms. The present invention relates more specifically to a rail and ramp system for attachment to a child&#39;s crib or bed that allows intended movement by the child to and from the crib or bed. 
   2. Description of the Related Art 
   Growing children progress rapidly through the use of a sequence of furniture and furnishings designed to provide a safe and comfortable sleeping environment for the child. A baby might initially be provided with a cradle as a sleeping environment when little or no movement of the child is anticipated during the night. Very quickly, however, the child graduates into a crib as a sleeping environment before eventually moving into a child or adult sized bed. The time period over which a child might utilize a crib can vary greatly depending upon the activity level of the child. Some children remain relatively docile, with limited movement, well past the age of two. Other children, however, become quite mobile and active as early as one year old, to the extent that a standard crib environment no longer comfortably or safely accommodates them. 
   Many crib manufacturers recommend that at a certain age one side of the crib be either removed or lowered as the structure of the crib might accommodate. Many cribs incorporate sliding side rails that allow the side to be lowered, either temporarily for intermittent movement in and out of the crib, or permanently as the child&#39;s age and activity level might merit. Some manufacturers recommend removing the sliding front panel when the child becomes mobile enough to get his or her arms fully over the top of the panel. The reasoning behind this recommendation is that even if the child falls from the crib, it is better to fall from mattress height than to have the child scale the front panel and fall from the panel height. Unfortunately, the simple raising or lowering of a side rail does not always accommodate the needs of many children who are active at a very young age. In addition, the lowered side rail, for many cribs, often provides inadequate side rail protection for the child when sleeping at night. All too often the height above the mattress is either too high for the child to easily access the crib when awake, or too low, such that the child might roll out from the crib while sleeping at night. 
   Some effort has been made in the past to provide for an intermediate solution to the problem of a young but active child in a crib sleeping environment. These efforts have generally been directed at providing for removable rails that could be positioned on the side of the crib in association with the mattress, or in some cases on the side of a child&#39;s bed in association with the mattress. In general, however, these mattress stabilized rail systems have either been too short or too long for a particular crib, i.e. they either extend beyond the posts of the crib or leave a significant and often unsafe opening in the side. In addition, these temporary and removable side rails fail to address the problem of providing easy access to the bed by the child who may be very mobile, but still not very tall, while at the same time providing for the safe containment of the child during sleep. Some of these efforts in the past include the following: 
   U.S. Pat. No. 5,781,945, issued to Scherer et al. entitled Portable Foldable Bed Rail. This patent describes a rail with two legs intended to be slid underneath the mattress and to hingedly support an oblong rail with hinged, collapsible end sections. The patent does not, however, address the concerns associated with variations in the height of the child, and facilitating movement in and out of the crib or bed. 
   U.S. Pat. No. 5,761,756, issued to Nowak et al. entitled Portable Bed Rail. This patent likewise describes a rail system that includes a pair of legs hingedly attached to the rail barrier, and intended to be slid under the mattress for support. The rail barrier component between the mattress legs is comprised of rigid telescoping poles that may be extended in length. Covering these poles and forming the barrier between them is a flexible fabric cover. 
   U.S. Pat. No. 329,663, issued to McMurray entitled Safety Attachment for Beds and Berths. This patent describes an early design disclosing a rail system with a pair of legs intended to be slid between the mattress and box spring, and hingedly supporting a rail on the side of the bed. The system includes a lower section that adds to the stability of the rail by insertion into a lower side support rail of the bed frame. A standard set of parallel slats form the rail barrier. 
   U.S. Pat. No. 4,178,645, issued to Cosme entitled Safety Bed. This patent describes a bed rail system having a pair of support legs inserted between the mattresses of the bed and being distinguished by a fold-down front rail structure. The generally tubular frame provides hinges at each end of the rail system that allow the usually upright rail to be folded down into a fully lowered and flat position against the side of the bed. Suitable locking mechanisms for maintaining the rail in an upright position are described. The complete disengagement of the rail from the leg components is also anticipated. 
   U.S. Pat. No. 5,596,776, issued to Huang entitled Collapsible Safeguard Rail Structure. This patent describes an assembly of tubular sections and hinged joints that provide a completely collapsing side rail for a bed. A pair of under-mattress legs is provided at each end, which supports an upright assembly of rail tubes. A midpoint in the rail system is likewise provided with hinged joints, which permit the rail not only to be folded against the mattress legs, but also to fold in half for compact storage. 
   U.S. Pat. No. 5,745,936, issued to Van McCutchen et al. entitled Safety Bed with Dual Purpose Side Panels. This patent describes an entire bed structure with side panel barriers extending along the entire length of the bed. The barriers are pivotally attached to a side component of the bed along its entire length. The patent anticipates raised, lowered, and intermediate positions for the side panels. 
   U.S. Pat. No. 5,671,490, issued to Wu entitled Collapsible Bed Rail Structure. This patent describes yet another collapsible rail system that incorporates a pair of between-mattress legs that are foldable against a generally rectangular rail frame that incorporates a flexible fabric barrier. Joints in the middle of the rectangular frame allow for the frame itself to be folded in half after collapsing the rail against the support legs. 
   U.S. Pat. No. 5,519,905, issued to Bernstein et al. entitled Bed Side Rails. This patent describes a rigid rail system intended to partially cover the side of a child&#39;s bed. Between-mattress legs are hingedly attached to the side rail in a manner that permits the complete lowering of the side rail from an upright position to a lowered and flat against the bed position when the rail is not in use. The rail itself comprises a rigid structure that is generally not collapsible or variable in length or height. 
   U.S. Pat. No. 5,577,277, issued to Sundberg et al. entitled Collapsible Bed Side Rail. This patent describes a generally rigid set of components intended to be attached together (as opposed to being hingedly folded) to form a side rail with between-mattress support legs. The rail barrier itself divides into two sections which compactly integrate the leg and support systems into a single compact storage unit. 
   U.S. Pat. No. 6,134,731, issued to Thom et al. entitled Adjustable Support Apparatus. This patent describes a partial wall rail barrier for a bed. The rail is intended primarily for older individuals, and provides a handle structure to be grasped by the person in bed in order to assist with lifting themselves to an upright position. 
   U.S. Pat. No. 6,453,490, issued to Cardinale entitled Bed Safety Guard. This patent is directed primarily to the between-mattress support structures and describes a system whereby the between-mattress legs extend entirely across the mattress to an attachment point on the opposite side of the bed. This arrangement is intended to provide improved support that prevents the rail from being dislodged or pushed away from the bed by the occupant. 
   U.S. Pat. No. 5,640,726 issued to Fichner-Rathus entitled Safety Rail for Sleeping Beds. This patent likewise describes a side rail system with between-mattress legs that extend completely across the mattress to an opposite side of the bed. Adjustments to both the cross mattress components and the side bed components allow for a tight fit on a variety of mattress structures. The rail itself is described as a rectangular frame with a mesh or fabric barrier. 
   While many attempts have been made in the past to provide removable rail systems, some of which are foldable into a lowered position, few if any of the devices provide for the needs of the intermediate aged child that is still young enough to utilize a crib as a sleeping environment, and yet active and mobile enough to be able to enter and exit the crib on their own. Rails currently available for retail purchase are typically either too short or too long to completely enclose a crib mattress. Those that are too short are intended to allow the child access to and from the crib when awake, but then leave the opening for the child to fall from while sleeping. Those that are too long cannot be safely used with cribs because the under-mattress support legs do not appropriately engage the mattress and are therefore not stable. In general, these rails do not permit the child to safely enter or exit the crib. The two goals of (1) providing a safe sleeping environment and (2) providing an accessible sleeping environment for the young, but active child, are simply not met by any system described in the prior art. It would be desirable therefore to have a removable rail system that positions a rail of adequate height on the side of a mattress so as to prevent a child from rolling from the crib during sleep, while at the same time providing a mechanism or component that allows the child to “scale” the rail from the outside of the crib so as to enter the crib to sleep. It would further be desirable for such a system to be safely attachable to or removable from the crib frame, and yet rigid enough upon attachment to be climbed upon by the child. 
   SUMMARY OF THE INVENTION 
   It is therefore an object of the present invention to provide a system that combines a side rail and a ramp structure that are attachable in combination to a crib or a bed in a manner that prevents the child in the crib or bed from rolling out during sleep, and at the same time provides a means for the child to climb or crawl from outside the crib, up to the railing, and over the railing so as to access the mattress of the crib or bed to go to sleep. The various preferred embodiments of the present invention each include a side rail component that is fixed to the crib or bed at each end by removable attachment straps or the like, and is rigidly connected to a pair of leg extensions that slide between the mattress and box spring of the crib or bed. A generally larger ramp component extends pivotally outward and downward from the side rail component to a point in contact with the floor on which the crib or bed is positioned. The angle and dimensions of the ramp are such as to permit an active child to crawl up the ramp to a point to where it becomes easy to climb over the rail on the side of the crib or bed. Various preferred embodiments of the present invention incorporate multiple hinged components within the ramp system so as to allow the alternate positioning of the ramp (in whole or in parts) in an extended configuration or a collapsed configuration against the crib or bed. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of a first embodiment of the present invention shown attached to a crib of standard configuration. 
       FIG. 2  is a detailed perspective view of the structure of the first preferred embodiment of the present invention shown in  FIG. 1 . 
       FIG. 3  is a reverse perspective view showing means for attaching the present invention to a crib of standard configuration. 
       FIG. 3A  is a detailed view of the attachment means shown generally in  FIG. 3 . 
       FIG. 4A  is a detailed view of an alternate attachment joint for connecting the ramp component of the present invention to the rail component. 
       FIG. 4B  is a second detailed view of the alternate removable connection joint shown in  FIG. 4A . 
       FIG. 5  is a perspective view of a second preferred embodiment of the present invention shown attached to a crib of standard configuration, the ramp component of the invention having a hinged feature. 
       FIG. 6  is a perspective view of the second preferred embodiment shown in  FIG. 5 , here in a folded configuration. 
       FIG. 7  is a detailed perspective view of the structure of the second preferred embodiment shown in  FIG. 5 . 
       FIG. 8  is a perspective view of a third preferred embodiment of the present invention shown attached to a crib of standard configuration, the ramp component having multiple ramp sections. 
       FIG. 9A  is a perspective view of the third preferred embodiment shown in  FIG. 8 , here in a folded configuration. 
       FIG. 9B  is a perspective view of the third preferred embodiment shown in  FIG. 8 , here in a partially folded configuration. 
       FIG. 9C  is a perspective view of the third preferred embodiment shown in  FIG. 8 , here in an alternate partially folded configuration. 
       FIG. 10  is a detailed perspective view of the multiple ramp sections embodiment of the present invention shown in  FIG. 8 . 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Reference is made first to  FIG. 1  for a brief description of the implementation of a first embodiment of the present invention on a standard crib enclosure.  FIG. 1  shows crib  10  as a typical crib enclosure with one removable side, leaving a mattress  11  surrounded on three sides by the crib end panels and side railing and open on a fourth side for placement of the present invention. Ramp/rail assembly  12  is positioned and attached to crib  10  as shown in  FIG. 1 . Ramp/rail assembly  12  includes rail sub-assembly  14  which is positioned directly onto crib  10  through the use of attachment bands  18   a  and  18   b . The mechanism for attachment in this manner is described in more detail below with reference to  FIGS. 3 and 3A . 
   Ramp/rail assembly  12  also comprises ramp sub-assembly  16  which extends downward and away from rail sub-assembly  14  positioned on crib  10 . Ramp sub- assembly  16  is comprised of ramp frame sub-assembly  22  and ramp surface  20 . 
   In the preferred embodiment shown in  FIG. 1 , ramp frame sub-assembly  22  is made up of semi-rigid tubular components joined together to form a generally rectangular frame as indicated in the drawing. Ramp surface  20  is positioned over and around ramp frame sub-assembly  22  so as to provide a light-weight, flexible surface to the rectangular plane defined by ramp frame sub-assembly  22 . As indicated in  FIG. 1 , ramp surface  20  may be a fabric material, most preferably an open mesh fabric constructed of soft polyester fibers, that is stretched across ramp frame sub-assembly  22 , around the individual edge components of ramp frame sub-assembly  22 , and sewn (or snapped, zipped, etc.) back onto itself or the ramp frame sub-assembly to form a secure platform made of fabric. 
   As shown in  FIG. 1 , ramp sub-assembly  16  is pivotally connected to rail sub-assembly  14  in a manner described in more detail below. In this configuration, the two primary components of ramp/rail assembly  12  define a first vertical plane comprising rail sub-assembly  14  and a second horizontally-angled plane defined by ramp sub-assembly  16 . The child may utilize the ramp/rail assembly  12  of the present invention by crawling up or down the ramp sub-assembly  16  of the device. The height of rail sub-assembly  14  is sufficiently low such that the child may readily enter the crib enclosure or exit the crib enclosure if such is the intent. Rail sub-assembly  14  is, however, sufficiently high as to prevent the child, when asleep or partially asleep, from unintentionally falling out of crib  10 . In this manner, the ramp/rail assembly  12  of the present invention provides an easy and safe means for a child to enter or exit crib  10 , when such is the child&#39;s intent. 
   Reference is now made to  FIG. 2  for a more detailed description of the structure of ramp/rail assembly  12  of the present invention as shown in  FIG. 1 . Once again ramp/rail assembly  12  is comprised of rail sub-assembly  14  and ramp sub-assembly  16 . The additional components not shown in  FIG. 1 , but which make up part of ramp/rail assembly  12 , include mattress legs  24   a  and  24   b . These mattress legs  24   a  and  24   b  are capped respectively with leg caps  25   a  and  25   b . Mattress legs  24   a  and  24   b  are attached to rail sub-assembly  14  in a manner described in more detail below and are utilized for the purpose of helping to stabilize rail sub-assembly  14  in its attachment to crib  10 . Mattress legs  24   a  and  24   b  are inserted and positioned below mattress  11  (shown in  FIG. 1 ) and in conjunction with attachment bands  18   a  and  18   b  serve to stabilize and position rail sub-assembly  14  on crib  10 , closely adjacent to mattress  11 . 
   As indicated above, ramp sub-assembly  16  is made up of ramp frame sub-assembly  22  and ramp surface  20  (not shown in  FIG. 2  for clarity). Ramp frame sub-assembly  22  is made up of a generally rectangular set of tubular components and joint connectors as shown. These components include ramp side braces  36   a  and  36   b , ramp base brace  37 , and ramp center brace  34 . Ramp base corner joints  26   a  and  26   b  serve to connect ramp side braces  36   a  and  36   b  to ramp base brace  37 . Ramp base center joint  28  serves to connect ramp center brace  34  to ramp base brace  37 . 
   Ramp frame sub-assembly  22 , and therefore ramp sub-assembly  16 , is connected to rail sub-assembly  14  by way of ramp top corner pivot joints  30   a  and  30   b  and ramp top center pivot joint  32 . Ramp top corner pivot joints  30   a  and  30   b , as well as ramp top center pivot joint  32 , are designed to position and fix ramp sub-assembly  16  side-to-side on rail sub-assembly  14 , but to permit the angular rotation of ramp sub-assembly  16  up and down in pivoting relationship to the plane of rail sub-assembly  14 . In other words, the corner and center pivot joints allow the user to lift ramp sub-assembly  16  and additionally allow variability in the height of the crib to which the present invention is mounted. 
   Rail sub-assembly  14  is comprised of rail top brace  45 , rail center brace  47 , and rail base brace  46 , all of which are in generally parallel, coplanar relationship to one another. Extending between rail top brace  45  and rail center brace  47  are a plurality of rail bars  38 . The base of rail sub-assembly  14  is made up of rail side braces  40   a  and  40   b  which are connected to rail top brace  45  by way of rail top joints  42   a  and  42   b , and are connected to rail base brace  46  by way of rail base joints  44   a  and  44   b . Rail side braces  40   a  and  40   b  are connected to rail center brace  47  by way of rail side joints  48   a  and  48   b.    
   As identified above, the pair of mattress legs  24   a  and  24   b , are connected to rail base brace  46  by way of mattress leg joints  50   a  and  50   b . In the preferred embodiment, these mattress leg joints  50   a  and  50   b  are fixed both laterally on rail base brace  46  and pivotally fixed (non-rotational) so as to facilitate the rigid placement of rail sub-assembly  14  adjacent the mattress of the crib. 
   Finally, additional support within rail sub-assembly  14  is provided by rail center brace support joints  52   a ,  52   b ,  54   a , and  54   b , which extend between and fix in parallel relationship, rail center brace  47  and rail base brace  46 . 
   Reference is now made to  FIG. 3  for a brief description of the use of attachment bands  18   a  and  18   b  in facilitating the fixed positioning of ramp/rail assembly  12  of the present invention on crib  10 . In this reverse view, and in the detailed view shown in  FIG. 3A , rail sub-assembly  14  of ramp/rail assembly  12  is positioned adjacent the mattress within crib  10 , but inside the posts or legs of crib  10  as shown. In this manner some rigidity is immediately obtained by the pressure of being positioned between the edge of the mattress, and the inside faces of the legs or posts of the crib. It is clear from  FIG. 3  that the dimensions of rail sub-assembly  14  of the present invention are dependent upon the dimensions of crib  10 , and derive from the distance between the center points of the interior faces of the legs or posts of the crib. In this manner, safe and secure placement and positioning of rail sub-assembly  14  is possible. 
   As shown in  FIG. 3A , rail side brace  40   b  and rail sub-assembly  14  are positioned against the interior face of the crib leg or post as shown. Attachment band  18   b  is wrapped around both rail side brace  40   b  and the leg or post of crib  10  as indicated. This attachment, in combination with the use of mattress legs  24   a  and  24   b  described above, provides a sufficiently rigid means for positioning the present invention on the crib. Attachment band  18   b  is, in the preferred embodiment, a “hook and loop” material type strap that may be wrapped back on itself to provide a secure but removable attachment point. Alternate methods for fixing rail sub-assembly  14  to the leg or post components of crib  10  are anticipated based upon the example of the attachment strap  18   b  shown. It is understood that the detail shown in  FIG. 3A  is repeated on the opposite end of crib  10  in a mirrored fashion. 
   Reference is now made to  FIGS. 4A and 4B  for a detailed description of one method for removably attaching ramp sub-assembly  16  of the present invention to rail sub-assembly  14 .  FIGS. 4A and 4B  show an alternate attachment joint that would replace ramp top corner pivot joints  30   a  and  30   b , all as shown in  FIG. 2 . Ramp top center joint  32  would likewise be modified into a partially open hook configuration, similar to the attachment joint structure shown in  FIGS. 4A and 4B  but without the closure mechanism. Under some circumstances it may be desirable to allow the user to completely remove ramp sub-assembly  16  from rail sub-assembly  14  for a variety of reasons, including more direct access to the side of the crib. The pivot joint structures shown in  FIGS. 4A and 4B  are designed to permit this separation of the components of the present invention. In  FIG. 4A , releasable top pivot joint  60  is shown comprised of release handle  62 , joint yoke  64 , and joint jaw  66 . Release handle  62  and joint jaw  66  are pivotally connected to joint yoke  64  by means of joint pivot bolt  68 . Release handle spring  69  is positioned in association with this pivot joint. Releasable top pivot joint  60  is positioned on ramp side brace  36   a  (in this example) and serves to replace ramp top corner pivot joint  30   a , shown in  FIG. 2 . In this manner, ramp side brace  36   a  is releasably attachable to rail center brace  47  of rail sub-assembly  14 . Rail center brace  47  is received into joint yoke  64  and maintained there, initially, by the downward weight of ramp sub-assembly  16 . Movement of release handle  62 , and therefore joint jaw  66 , closes joint jaw  66  around rail center brace  47  to adequately secure the pivoting joint.  FIG. 4B  shows in greater detail the manner in which the release of release handle  62  closes joint jaw  66  around rail center brace  47  so as to hold rail center brace  47  captive within joint yoke  64 . 
   The above described first preferred embodiment of the present invention is designed to used by a child that is capable of climbing or crawling up the ramp component to the rail component and thereafter climbing over the rail component into the crib to sleep on the mattress. When the child wakes from sleep and wishes to exit the crib, the present invention provides such an exit. The child, when awake and alert, is capable of climbing over the rail component to land on the ramp component. The ramp component is sized and angled so that the child crawling or “falling” from over the rail component would be stopped in his or her vertical descent by the ramp platform material and would be slow to slide down the ramp because of the friction the surface provides. In this manner the child may exit to the floor from the otherwise too high crib mattress surface without the assistance of an adult. The ramp may be left permanently positioned on the side of the crib for this purpose or may be removed as needed if it is configured with the releasable connector joints described in  FIGS. 4A and 4B . 
   Reference is now made to  FIGS. 5–7  for a detailed description of a second preferred embodiment of the present invention. Ramp/rail assembly  12  shown in  FIG. 5  is designed to have a folding function that permits the user to move ramp sub-assembly  16  into a planar position adjacent the side of crib  10 , so as to allow the user more direct access to the crib. The folded configuration of this embodiment is shown in  FIG. 6 .  FIG. 5  discloses the extended configuration of the embodiment, wherein ramp/rail assembly  12  is made up of folding ramp sub-assembly  70 , which itself is comprised of folding ramp lower frame sub-assembly  72 , and folding ramp upper frame sub-assembly  74 . Joints that are described in more detail below connect folding ramp lower frame sub-assembly  72  to folding ramp upper frame sub-assembly  74  and permit the folding or bending of folding ramp sub-assembly  70  in a manner that allows it to be flatly positioned against the side of crib  10  as shown in  FIG. 6 . 
   Reference is now made to  FIG. 7  for a detailed description of the specific components that make up the second preferred embodiment shown in  FIG. 5  and  FIG. 6 . It should be noted that rail sub-assembly  14  in this embodiment remains structured exactly the same as rail sub-assembly  14  in the initial preferred embodiment mentioned above. Folding ramp sub-assembly  70  once again is comprised of folding ramp lower frame sub-assembly  72  and folding ramp upper frame sub-assembly  74 . Folding ramp lower frame sub-assembly  72 , itself is comprised of ramp lower side braces  76   a  and  76   b , as well as ramp lower center brace  78 . Ramp lower base brace  79  is essentially identical to ramp base brace  37  shown in the first embodiment described above. Folding ramp upper frame sub-assembly  74  is comprised of ramp upper side braces  80   a  and  80   b , as well as ramp upper center brace  82 . Ramp upper side braces  80   a  and  80   b  are respectively connected to ramp lower side braces  76   a  and  76   b  by means of ramp brace hinges  84 . Ramp upper center brace  82  is likewise connected to ramp lower center brace  78  by means of a ramp brace hinge  84 . Ramp brace hinges  84  are constructed so as to fold in the direction indicated in the drawings, such that folding ramp upper frame sub-assembly  74  may be rotated upward, thereby drawing in folding ramp lower frame sub-assembly  72  into the coplanar position described above. The hinges  84 , however, are structured so as to alternately (and normally) bring the ramp lower side braces  76   a  and  76   b  into alignment with ramp upper side braces  80   a  and  80   b  (likewise with center braces  82  and  78 ) and to remain rigid in that position preventing the further bending or collapsing of the frame downward. Such hinges structured to stop once the alignment described above has occurred, are well known in the art. 
   The above described second preferred embodiment of the present invention finds practicality where the parent or caregiver finds it necessary to frequently access the side of the crib to attend to the child. In so far as the ramp, in its lowered position, would likely serve as a barrier to close access, the second embodiment provides a folding ramp that almost entirely eliminates the “protrusion” that the extended ramp would provide on the side of the crib. The hinge structure, and its location on the ramp frame, is such that the ramp may be folded upward with the appropriate force being exerted inward on the lower edge of the ramp towards the crib. In this manner, the adult or care giver may generally fold the ramp by pushing against the lower edge of the ramp with their foot. Extending the ramp again can be accomplished by drawing the lower edge of the ramp out again from the crib and allowing gravity to pull the ramp sections once again into an inclined plane configuration. Hinges of the type that bend in only one direction (and provide stiff resistance to bending in the opposite direction) are well known in the art. 
   Reference is now made to  FIGS. 8 ,  9 A,  9 B,  9 C and  10  for a detailed description of a third alternative preferred embodiment of the present invention. In  FIG. 8 , ramp/rail assembly  12  is seen once again to be comprised of rail sub-assembly  14 , but instead of a single ramp sub-assembly attached to rail sub-assembly  14 , a dual folding ramp structure is disclosed. This dual folding ramp system is comprised of dual-folding ramp right sub-assembly  90 , and dual-folding ramp left sub-assembly  96 . Dual-folding ramp right sub-assembly  90  is comprised of dual-folding ramp right lower frame sub-assembly  92 , and dual-folding ramp right upper frame sub-assembly  98 . Likewise, dual-folding ramp left sub-assembly  96  is comprised of dual-folding ramp left lower frame sub-assembly  94 , and dual-folding ramp left upper frame sub-assembly  100 . The manner in which the assemblies of the dual-folding ramp structure fold with respect to one another is identical to that described above in the second preferred embodiment utilizing hinges  84 . In this case, however, two separate folding ramps are positioned so as to permit the user to either fold both ramps at the same time, or a single ramp at a time. These various folding configurations are shown in  FIGS. 9A ,  9 B, and  9 C.  FIG. 9A  shows the dual folding ramp system wherein both dual-folding ramp right sub-assembly  90  and dual-folding ramp left sub-assembly  96  are each folded into coplanar relationship with rail sub-assembly  14 , close to the side of crib  10 .  FIG. 9   b  shows dual-folding ramp right sub-assembly  90  extended into its ramp configuration while dual-folding ramp left sub-assembly  96  remains folded against the side of crib  10 . In the opposite configuration,  FIG. 9   c  discloses dual-folding ramp left sub-assembly  96  extended and dual-folding ramp right sub-assembly  90  folded against the side of crib  10 . 
   Reference is finally made to  FIG. 10  for a detailed description of the additional components incorporated into the structure associated with the above described dual-folding ramp system. Here again, rail sub-assembly  14  is identical to the rail sub-assembly described above with respect to the first and second preferred embodiments. Dual-folding ramp right lower frame sub-assembly  92  is made up of right ramp lower side brace  110   a , right ramp lower base brace  111   a , and right ramp lower center brace  112   a . Likewise, dual-folding ramp left lower frame sub-assembly  94  is made up of left ramp lower side brace  110   b , left ramp lower base brace  111   b , and left ramp lower center brace  112   b . The joints for connecting the center and side braces described above include right ramp lower center base joint  114   a , left ramp lower center base joint  114   b , right ramp lower corner base joint  116   a , and left ramp lower corner base joint  116   b.    
   The dual-folding ramp right upper frame sub-assembly  98  is comprised of right ramp upper center brace  118   a  and right ramp upper side brace  122   a . The dual-folding ramp left upper frame sub-assembly  100  is comprised of left ramp upper center brace  118   b  and left ramp upper side brace  122   b . The joints for connecting the center and side braces of dual-folding ramp right upper frame sub-assembly  98  and dual-folding ramp left upper frame sub-assembly  100  include right ramp upper side pivot joint  120   a , left ramp upper side pivot joint  120   b , right ramp upper center pivot joint  124   a , and left ramp upper center pivot joint  124   b.    
   The third preferred embodiment described above finds practicality where both use of the ramp and direct access to the side of the crib are desired. Although it is obviously necessary for the railing of the present invention to extend down the entire length of the open side of the crib, it is not typically necessary for the ramp to be this wide. The third embodiment therefore provides for a system that accommodates both the use of the ramp by the child and access to the side of the crib by the adult. The process of folding or extending each ramp section is the same as with the second embodiment described above but may be accomplished with both ramp sections together or each ramp section independently. The division of the ramp may be into two sections (as shown) or may be more under certain circumstances. Likewise the division of the ramp may be into equal sections (as shown) or unequal under certain circumstances. In any event, the third embodiment provides versatility in user configuration of the ramp component of the present invention. 
   Although the present invention has been described in conjunction with a number of preferred embodiments, those skilled in the art will recognize further alterations of the structures described that still fall within the scope of the invention as defined by the claims that follow. For example, but without limitation, the components of the frame structures of the invention as described are generally shown as round tubular sections. Those skilled in the art will recognize that longitudinal sections of a solid nature and/or of alternate cross-section (such as square) are possible. Likewise, the material from which these frame sections might be constructed could be any of a number of rigid or semi-rigid compositions available for such longitudinal elements. For example, but again without limitation, the tubular sections might be constructed of strong (schedule  40  or greater) PVC pipe sections or may be constructed of metal tubular components. Those skilled in the art will recognize the balance required between rigidity and flexibility in selecting the most appropriate materials. Finally, again without limitation, the construction of the platform that provides the climbing surface in the present invention may be from any of a number of different materials from a coarse mesh to a tightly woven fabric. Comfort and strength will generally govern the choice of material for the platform.