FIELD OF INVENTION  
         [0001]    The instant invention relates to the field of convertible units for use with babies and very young children; in particular to units which may be easily converted to a crib or child&#39;s bed-side sleeping enclosure, hereinafter referred to for convenience as a “co-sleeper”, that attaches securely to the parents&#39; bed. The invention also includes a stand-alone unit for use with existing cribs.  
         BACKGROUND OF THE INVENTION  
         [0002]    Furniture and fixtures for use by babies and small children often presents a problem for parents with limited living space. For this reason it is desirable that such furniture serve more than one purpose. A bedside co-sleeper is very useful for an infant or very young child as it prevents a parent from having to get out of bed to deal with a child requiring minor attention or comforting. If the co-sleeper can then be put to other uses, the parents will save both space and the cost of other furniture. Various examples of such multi-purpose children&#39;s furniture have been patented and sold.  
           [0003]    In U.S. Pat. No. 5,349,709, issued to Cheng teaches a folding combination playpen and baby bed having an elevated floorboard. U.S. Pat. No. 5,339,470, issued to Shamie discloses a combination foldable playpen and dressing/changing table. Mariol adds an upper level to a playpen to provide a bassinet. The short legs of the upper level are inserted into openings in the top of the vertical supports of the playpen. (U.S. Pat. No. 5,553,336). U.S. Pat. No. 2,632,186, issued to Berk et al. discloses a portable combination crib and playpen. Saldana teaches a unit designed for home and travel that may be used as a support for a playpen, bassinet or baby chair (U.S. Pat. No. 2,691,176).  
           [0004]    Beside cribs that attached to the parents&#39; bed were known at the turn of the century (U.S. Pat. Nos. 5,548,005; 620,069; 1,138,451; 1,283,169; 1,267,244) but fell out of favor for many years. Recently there has been a resurgence in the practice of having babies adjacent the parents&#39; bed. Such bed-side devices are taught in U.S. Pat. No. 5,172,435 to Griffin et al.; U.S. Pat. No. 5,148,561 to Tharalson et al; and U.S. Pat. No. 5,293,655 to Van Winkle et al.  
           [0005]    It is an objective of the present invention to provide a crib that can be adapted for use as a baby co-sleeper. It is a further objective of the invention to provide a stand-alone unit that can be used to convert an existing crib to a co-sleeper. It is still a further objective of the present invention that the unit provide a means for adjusting the height of the co-sleeper unit within the crib structure so as to be adaptable for use with platform-style beds that are typically lower than conventional beds. Finally, it is an objective of the invention that the stand-alone unit be readily collapsible for transport and storage. Other features and advantages of the invention will be seen from the following description and drawings.  
         SUMMARY OF THE INVENTION  
         [0006]    The present invention addresses all of the deficiencies of prior art convertible co-sleeper inventions and satisfies all of the objectives described above.  
           [0007]    A crib convertibly adapted for use as a co-sleeper providing the desired features may be constructed from the following components. A first rigid enclosure with an open top, a floor, a front wall, and at least one surrounding wall is provided. The front wall is removably mounted to the crib and the enclosure is of a first predetermined height. A second enclosure sized to fit substantially within the first enclosure and having an open top, a bottom and at least one surrounding wall is provided. Means are provided for adjustably supporting the second enclosure within the first enclosure at at least one predetermined distance from the top of the first enclosure. A securing strap assembly for securing the crib to a parental bed is provided. When the front wall is removed from the crib, the second enclosure is supported by the supporting means, the securing strap assembly is properly positioned and the crib is secured to the parental bed the crib will serve as a co-sleeper.  
           [0008]    In a variant of the invention, a crib convertibly adapted for use as a co-sleeper may be constructed from the following components. A rigid first enclosure having an open top, a floor, a front wall, a back wall, a first side wall and a second side wall is provided. The front wall is removably mounted to the crib and the first enclosure is of a first predetermined height. A second enclosure having an open top, a floor, a front, a back, a first side and a second side is provided.  
           [0009]    First, second, third and fourth mounting rails, each of the rails having a first end and a second end are provided. The first mounting rail is affixed at its first end and its second end to the first side wall adjacent the front wall. The second mounting rail is affixed at its first end and its second end to the first side wall adjacent the back wall. The third mounting rail is affixed at its first end and its second end to the second side wall adjacent the front wall. The fourth mounting rail is affixed at its first end and its second end to the second side wall adjacent the back wall. Means are provided for adjustably mounting the second enclosure to the first, second, third and fourth mounting rails within the first enclosure at at least one predetermined distance from the top of the first enclosure. A securing strap assembly for securing the crib to a parental bed is provided. When the front wall is removed from the crib, the second enclosure is mounted within the first enclosure, the securing strap assembly is properly positioned and the crib is secured to the parental bed the crib will serve as a co-sleeper.  
           [0010]    In a further variant of the invention, the back, first side and second side of the second enclosure are of a second predetermined height and the front of the second enclosure is of a third predetermined height, less than the second predetermined height.  
           [0011]    In still a further variant of the invention, the first side and the second side of the second enclosure extend past a front edge of the first side wall and a front edge of the second side wall, respectively, for a second predetermined distance.  
           [0012]    In yet a further variant, the means for adjustably mounting the second enclosure to the first, second, third and fourth mounting rails includes first, second, third and fourth locking guide tube assemblies. Each of the locking assemblies includes a length of rigid tubing. The tubing is sized and shaped to fit slidably over one the first, second, third and fourth mounting rails. Means for attaching the locking assembly to the second enclosure, and means for releasably securing the locking assembly to one of the mounting rails are provided.  
           [0013]    The first locking guide assembly is attached to the second enclosure at an intersection of a front edge and a top edge of the first side. The second locking guide assembly is attached to the second enclosure at an intersection of a back edge and the top edge of the first side. The third locking guide assembly is attached to the second enclosure at an intersection of a front edge and a top edge of the second side. The fourth locking guide assembly is attached to the second enclosure at an intersection of a back edge and the top edge of the second side.  
           [0014]    In still a further variant of the invention, the means for adjustably mounting the second enclosure to the first, second, third and fourth mounting rails includes first, second, third and fourth guide tube assemblies. Each of the guide tube assemblies includes a length of rigid tubing. The tubing is sized and shaped to fit slidably over one the first, second, third and fourth mounting rails. Means are provided for attaching the guide tube assembly to the second enclosure. The first guide tube assembly is attached to the second enclosure at an intersection of the front edge and a bottom edge of the first side. The second guide tube assembly is attached to the second enclosure at an intersection of the back edge and the bottom edge of the first side. The third guide tube assembly is attached to the second enclosure at an intersection of the front edge and a bottom edge of the second side. The fourth guide tube assembly is attached to the second enclosure at an intersection of the back edge and the bottom edge of the second side.  
           [0015]    In yet a further variant of the invention, the means for releasably securing the locking guide tube assembly to one of the mounting rails includes a locking lever. The locking lever includes a handle portion and extends to a pivot portion and further extends to a cam portion. An orifice in the rigid tubing of the locking guide tube assembly is provided. The orifice is sized, shaped, and located to permit the cam portion of the locking lever to bear upon one of the first, second, third and fourth mounting rails.  
           [0016]    A pivot mounting is provided. The pivot mounting is affixed adjacent the orifice in the rigid tubing and is sized, shaped, and located to permit pivotal mounting of the pivot portion of the locking lever. A pivot pin is provided. The pin pivotally secures the locking lever to the pivot mounting so that the locking lever will secure the locking guide tube assembly to the mounting rail in a first position and permit the mounting rail to slide within the rigid tubing of the locking guide tube assembly in a second position.  
           [0017]    In still a further variant, the means for releasably securing the locking guide tube assembly to one of the mounting rails includes a series of orifices. The orifices are spaced along a length of each the first, second, third and fourth mounting rails. A plunger pin is provided. The plunger pin has a first end and a second end and has an operating knob at the first end and an engaging end at the second end. The engaging end is sized and shaped to fit slidably within one of the orifices in the mounting rails. A plunger pin housing is provided. The housing is affixed to the locking guide tube assembly and is sized, shaped and located to position the plunger pin orthogonal to the mounting rail so that the plunger pin will engage the orifices in the mounting rail.  
           [0018]    A return spring is provided. The return spring is located within the plunger pin housing and is sized, shaped and located to cause the plunger pin to be urged toward the mounting rail. When the operating knob is withdrawn away from the mounting rail the plunger pin will be withdrawn from one of the orifices and the mounting rail will slide within the rigid tubing of the locking guide tube assembly. When the operating knob is released the plunger pin will engage one of the orifices in the mounting rail and the locking guide tube assembly will be secured to it.  
           [0019]    In another variant, the means for releasably securing the locking guide tube assembly to one of the mounting rails includes at least two vertical slits. The slits extend from a lower end of the rigid tubing of the locking guide tube assembly upwardly for a first predetermined distance. An external tapered thread extends from the lower end of the rigid tubing upwardly for the first predetermined distance. A threaded collar is provided. The collar is sized, shaped, and located to threadedly engage the tapered thread of the rigid tubing. When the threaded collar is rotated in a first, tightening direction the vertical slits will permit the rigid tubing to bear frictionally against one of the first, second, third and fourth mounting rails. When the threaded collar is rotated in a second, loosening direction the vertical slits will permit the rigid tubing to slide over one of the first, second, third and fourth mounting rails, permitting vertical adjustment of the second enclosure.  
           [0020]    In still another variant of the invention, the securing strap assembly for securing the crib to a parental bed further includes a strap member of a length greater than twice the width of the parental bed having a first end and a second end. A resistance plate member is provided that has at least two slots vertically aligned and centrally located through which the strap member is threaded such that the first end and the second end are substantially equidistant from the plate member. A strap member receiving means is fixedly attached to the first side wall and second side wall of the crib. Attachment cooperation means are slidably engaged near the first end and near the second end of the strap member for reversible connection to the strap member receiving means. Means for adjusting a length of the strap member and fixedly tightening it after connecting the attachment cooperation means to the strap member receiving means are provided. The strap member is properly positioned when located under a mattress of the parental bed and held in place by the resistance plate member located vertically at a side of the parental bed opposite placement of the crib and the strap member is tightened so the crib is held fast to the parental bed.  
           [0021]    In yet another variant, the securing strap assembly for securing the crib to a parental bed includes first and second guide slots. The guide slots are sized, shaped and located upon the first and second side walls of the crib to constrain the strap member adjacent its first end and its second end, thereby more securely holding the crib to the parental bed.  
           [0022]    In yet a further variant of the invention, a crib convertibly adapted for use as a co-sleeper includes a rigid first enclosure. The first enclosure has an open top, a floor, a front wall, a back wall, a first side wall and a second side wall. The front wall is removably mounted to the crib. The first enclosure is of the second predetermined height. A second enclosure is provided. The second enclosure has an open top, a floor, a front, a back, a first side and a second side. First, second, third and fourth mounting rails are provided. Each of the rails has a first end and a second end. The second and fourth mounting rails are located adjacent to and bear upon the back wall of the first enclosure.  
           [0023]    A rear upper connecting rail is provided. The rear rail has a first end and a second end and is removably attached at its first end to the first end of the second mounting rail and removably attached at its second end to the first end of the fourth mounting rail. A first side upper connecting rail is provided. The first side rail has a first end and a second end and is removably attached at its first end to the first end of the second mounting rail and removably attached at its second end to the first end of the first mounting rail. A second side upper connecting rail is provided. The second side rail has a first end and a second end and is removably attached at its first end to the first end of the fourth mounting rail and removably attached at its second end to the first end of the third mounting rail.  
           [0024]    Four mounting feet are provided. Each of the feet is sized and shaped to attach to the second end of one of the first, second, third and fourth mounting rails and to grip frictionally the floor of the first enclosure. Means are provided for adjustably mounting the second enclosure to the first, second, third and fourth mounting rails within the first enclosure at at least one predetermined distance from the top of the first enclosure.  
           [0025]    A securing strap assembly is provided for securing the crib to a parental bed. When the front wall is removed from the crib, the second enclosure is mounted within the first enclosure, the securing strap assembly is properly positioned and the crib is secured to the parental bed, the crib will serve as a co-sleeper.  
           [0026]    In still a further variant, a crib convertibly adapted for use as a co-sleeper also includes at least one pair of tensioning devices. The tensioning devices have a threaded rod with a first end, a second end, and an attachment plate. The plate is orthogonaly mounted to the first end of the threaded rod. At least one pair of threaded orifices passing orthogonaly through at least two of the second and fourth mounting rails and the first and third mounting rails is provided. The orifices are sized, shaped, and located to receive threadedly the second end of the threaded rods of the tensioning devices such that the threaded rods are collinear. When the threaded rods of the tensioning devices are rotated outwardly from two of the second and fourth mounting rails and the first and third mounting rails, the attachment plates will bear against the first side wall and the second side wall of the crib, thereby stabilizing the second enclosure within the crib.  
           [0027]    In yet another variant, the tensioning device further includes a stabilizing point. The point is collinear with the threaded rod and mounted orthogonaly to the attachment plate, thereby preventing movement of the second enclosure with respect to the crib.  
           [0028]    In still a further variant of the invention, a second enclosure for use with an existing crib is provided, along with a securing strap assembly for securing the crib to a parental bed. Mounting rails for the second enclosure are secured to the first and second side walls of the crib.  
           [0029]    In yet another variation, for use with an existing crib, mounting rails for the second enclosure are free-standing and are removably attached together with a rear upper connecting rail, a first side upper connecting rail and a second side upper connecting rail. The second and fourth mounting rails are located adjacent to and bear upon the back wall of the existing crib. A securing strap assembly for securing the crib to the parental bed is also provided. In still another variant, at least one pair of tensioning devices is provided. In still another variation, tensioning devices bear upon first and second side walls of the existing crib and serve to stabilize the second enclosure within the existing crib. In a final variant, the tensioning devices include stabilizing points to prevent movement of the stabilizing devices with respect to the crib. 
       
    
    
     DESCRIPTION OF THE DRAWINGS  
       [0030]    [0030]FIG. 1 is a perspective view of a first embodiment of the invention illustrating a crib with removable front wall with a co-sleeper nest installed;  
         [0031]    [0031]FIG. 2 is a perspective view of a first enclosure crib with a removable front wall used as part of a second embodiment of the invention;  
         [0032]    [0032]FIG. 3 is a perspective view of a first embodiment of second enclosure used with the FIG. 2 crib in the second embodiment of the invention;  
         [0033]    [0033]FIG. 4 is a perspective view of the second embodiment illustrating a securing strap assembly for attachment to a parental bed;  
         [0034]    [0034]FIG. 5 is a side elevational view of the FIG. 4 embodiment illustrating the projection of the second enclosure past a front of the first enclosure;  
         [0035]    [0035]FIG. 6 is a detailed perspective view of a first embodiment of a locking guide tube assembly and a guide tube assembly;  
         [0036]    [0036]FIG. 7 is a detailed cross-sectional side view of the first embodiment of the locking guide tube assembly;  
         [0037]    [0037]FIG. 8 is a detailed cross-sectional side view of the second embodiment of the locking guide tube assembly;  
         [0038]    [0038]FIG. 9 is a detailed cross-sectional side view of the third embodiment of the locking guide tube assembly;  
         [0039]    [0039]FIG. 10 is a perspective view of the second embodiment attached to a parental bed using the securing strap assembly;  
         [0040]    [0040]FIG. 11 is a detailed perspective view of a guide slot assembly attached to a side of the crib;  
         [0041]    [0041]FIG. 12 is a perspective view of a second embodiment of a second enclosure illustrating supporting feet and rear and side connecting rails;  
         [0042]    [0042]FIG. 13 is a perspective view of a third embodiment of a second enclosure illustrating tensioning devices for attachment to a crib;  
         [0043]    [0043]FIG. 14 is a detailed perspective view of the tensioning device illustrating a stabilizing point;  
         [0044]    [0044]FIG. 15 is a front view of a third embodiment of the invention including the FIG. 13 second enclosure;  
         [0045]    [0045]FIG. 16 is a perspective view of a fourth embodiment of the invention illustrating an existing crib with the FIG. 3 embodiment of the second enclosure attached; and  
         [0046]    [0046]FIG. 17 is a perspective view of a fifth embodiment of the invention illustrating an existing crib with the FIG. 13 embodiment of the second enclosure attached. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0047]    [0047]FIG. 1 illustrates a crib convertibly adapted for use as a co-sleeper  10  providing the desired features. The crib  10  may be constructed from the following components. A first rigid enclosure  14  with an open top  18 , a floor  22 , a front wall  26 , and at least one surrounding wall  30  is provided. The front wall  26  is removably mounted to the crib  10  and the first enclosure  14  is of a first predetermined height  34 . A second enclosure  38  sized to fit substantially within the first enclosure  14  and having an open top  42 , a bottom  46  and at least one surrounding wall  50  is provided. Means  54  are provided for adjustably supporting the second enclosure  38  within the first enclosure  14  at at least one predetermined distance  58  from the top  18  of the first enclosure  14 . A securing strap assembly  60  for securing the crib  10  to a parental bed (not shown) is provided. When the front wall  26  is removed from the crib  10 , the second enclosure  38  is supported by the supporting means  54 , the securing strap assembly  60  is properly positioned and the crib  10  is secured to the parental bed  62  the crib  10  will serve as a co-sleeper.  
         [0048]    In a variant of the invention, illustrated in FIGS.  2 - 4 , a crib convertibly adapted for use as a co-sleeper  10  may be constructed from the following components. A rigid first enclosure  66  having an open top  70 , a floor  74 , a front wall  78 , a back wall  82 , a first side wall  86  and a second side wall  90  is provided. The front wall  78  is removably mounted to the crib  10  and the first enclosure  66  is of a first predetermined height  34 . As illustrated in FIG. 3, a second enclosure  98  having an open top  102 , a floor  106 , a front  110 , a back  114 , a first side  118  and a second side  122  is provided.  
         [0049]    First  126 , second  130 , third  134  and fourth  138  mounting rails, each of the rails  126 ,  130 ,  134 ,  138  having a first end  142  and a second end  146  are provided. The first mounting rail  126  is affixed at its first end  142  and its second end  146  to the first side wall  86  adjacent the front wall  78 . The second mounting rail  130  is affixed at its first end  142  and its second end  146  to the first side wall  86  adjacent the back wall  82 . The third mounting rail  134  is affixed at its first end  142  and its second end  146  to the second side wall  90  adjacent the front wall  78 . The fourth mounting rail  138  is affixed at its first end  142  and its second end (not shown) to the second side wall  90  adjacent the back wall  82 . As illustrated in FIGS. 3 and 4, means  150  are provided for adjustably mounting the second enclosure  98  to the first  126 , second  130 , third  134  and fourth  138  mounting rails within the first enclosure  66  at at least one predetermined distance  58  from the top  70  of the first enclosure  66 . A securing strap assembly  60  for securing the crib  10  to a parental bed (not shown) is provided. When the front wall  78  is removed from the crib  10 , the second enclosure  98  is mounted within the first enclosure  66 , the securing strap assembly  60  is properly positioned and the crib  10  is secured to the parental bed the crib  10  will serve as a co-sleeper.  
         [0050]    In a further variant of the invention, as illustrated in FIG. 3, the back  114 , first side  118  and second side  122  of the second enclosure  98  are of a second predetermined height  154  and the front  110  of the second enclosure  98  is of a third predetermined height  158 , less than the second predetermined height  154 .  
         [0051]    In still a further variant of the invention, as illustrated in FIG. 5, the first side  118  and the second side  122  of the second enclosure  98  extend past a front edge  162  of the first side wall  86  and a front edge  166  of the second side wall  90 , respectively, for a second predetermined distance  170 .  
         [0052]    In yet a further variant, as illustrated in FIGS. 6 and 7, the means  150  for adjustably mounting the second enclosure  98  to the first  126 , second  130 , third  134  and fourth  138  mounting rails includes first  174 , second (not shown), third (not shown) and fourth (not shown) locking guide tube assemblies. Each of the locking assemblies  174 , (not shown) includes a length of rigid tubing  190 . The tubing  190  is sized and shaped to fit slidably over one the first  126 , second  130 , third  134  and fourth  138  mounting rails. Means  194  for attaching the locking assembly  174  to the second enclosure  98 , and means  198  for releasably securing the locking assembly  174  to one of the mounting rails  126 ,  130 ,  134 ,  138  are provided.  
         [0053]    The first locking guide assembly  174  is attached to the second enclosure  98  adjacent an intersection  202  of a front edge  206  and a top edge  210  of the first side  118 . The second locking guide assembly is attached to the second enclosure  98  adjacent an intersection (not shown) of a back edge (not shown) and the top edge  210  of the first side  118 . The third locking guide assembly is attached to the second enclosure  98  at an intersection (not shown) of a front edge (not shown) and a top edge (not shown) of the second side  122 . The fourth locking guide assembly is attached to the second enclosure  98  at an intersection (not shown) of a back edge (not shown) and the top edge (not shown) of the second side  122 .  
         [0054]    In still a further variant of the invention, as illustrated in FIG. 6, the means  150  for adjustably mounting the second enclosure  98  to the first  126 , second  130 , third  134  and fourth  138  mounting rails includes first  242 , second (not shown), third (not shown) and fourth (not shown) guide tube assemblies. Each of the guide tube assemblies  242 , (not shown) includes a length of rigid tubing  258 . The tubing  258  is sized and shaped to fit slidably over one the first  126 , second  130 , third  134  and fourth  138  mounting rails. Means  262  are provided for attaching the guide tube assembly  242  to the second enclosure  98 . The first guide tube assembly  242  is attached to the second enclosure  98  adjacent an intersection  266  of the front edge  206  and a bottom edge  270  of the first side  118 . The second guide tube assembly is attached to the second enclosure  98  adjacent an intersection (not shown) of the back edge (not shown) and the bottom edge  270  of the first side  118 . The third guide tube assembly is attached to the second enclosure  98  adjacent an intersection (not shown) of the front edge (not shown) and a bottom edge (not shown) of the second side  122 . The fourth guide tube assembly is attached to the second enclosure  98  adjacent an intersection (not shown) of the back edge (not shown) and the bottom edge of the second side  122 .  
         [0055]    In yet a further variant of the invention, as illustrated in FIG. 7, the means  198  for releasably securing the locking guide tube assembly  174  to one of the mounting rails  126 ,  130 ,  134 ,  138  includes a locking lever  290 . The locking lever  290  includes a handle portion  294  and extends to a pivot portion  298  and further extends to a cam portion  302 . An orifice  306  in the rigid tubing  190  of the locking guide tube assembly  174  is provided. The orifice  306  is sized, shaped, and located to permit the cam portion  302  of the locking lever  290  to bear upon one of the first  126 , second  130 , third  134  and fourth  138  mounting rails.  
         [0056]    A pivot mounting  310  is provided. The pivot mounting  310  is affixed adjacent the orifice  306  in the rigid tubing  190  and is sized, shaped, and located to permit pivotal mounting of the pivot portion  298  of the locking lever  290 . A pivot pin  314  is provided. The pin  314  pivotally secures the locking lever  290  to the pivot mounting  310  so that the locking lever  290  will secure the locking guide tube assembly  174  to the mounting rail  126 ,  130 ,  134 ,  138  in a first position  318  and permit the mounting rail  126 ,  130 ,  134 ,  138  to slide within the rigid tubing  190  of the locking guide tube assembly  174  in a second position  318 .  
         [0057]    In still a further variant, as illustrated in FIG. 8, the means for releasably securing the locking guide tube assembly  174  to one of the mounting rails  126 ,  130 ,  134 ,  138  includes a series of orifices  322 . The orifices  322  are spaced along a length  326  of each the first  126 , second  130 , third  134  and fourth  138  mounting rails. A plunger pin  330  is provided. The plunger pin  330  has a first end  334  and a second end  338  and has an operating knob  342  at the first end  334  and an engaging end  346  at the second end  338 . The engaging end  346  is sized and shaped to fit slidably within one of the orifices  322  in the mounting rails  126 ,  130 ,  134 ,  138 . A plunger pin housing  350  is provided. The housing  350  is affixed to the locking guide tube assembly  174  and is sized, shaped and located to position the plunger pin  330  orthogonal to the mounting rail  126 ,  130 ,  134 ,  138  so that the plunger pin  330  will engage the orifices  322  in the mounting rail  126 ,  130 ,  134 ,  138 .  
         [0058]    A return spring  354  is provided. The return spring  354  is located within the plunger pin housing  350  and is sized, shaped and located to cause the plunger pin  330  to be urged toward the mounting rail  126 ,  130 ,  134 ,  138 . When the operating knob  342  is withdrawn away from the mounting rail  126 ,  130 ,  134 ,  138  the plunger pin  330  will be withdrawn from one of the orifices  322  and the mounting rail  126 ,  130 ,  134 ,  138  will slide within the rigid tubing  190  of the locking guide tube assembly  174 . When the operating knob  342  is released the plunger pin  330  will engage one of the orifices  322  in the mounting rail  126 ,  130 ,  134 ,  138  and the locking guide tube assembly  174  will be secured to it.  
         [0059]    In another variant, as illustrated in FIG. 9, the means for releasably securing the locking guide tube assembly  174  to one of the mounting rails  126 ,  130 ,  134 ,  138  includes at least two vertical slits  358 . The slits  358  extend from a lower end  362  of the rigid tubing  190  of the locking guide tube assembly  174  upwardly for a first predetermined distance  366 . An external tapered thread  370  extends from the lower end  362  of the rigid tubing  190  upwardly for the first predetermined distance  366 . A threaded collar  374  is provided. The collar  374  is sized, shaped, and located to threadedly engage the tapered thread  370  of the rigid tubing  190 . When the threaded collar  374  is rotated in a first  378 , tightening direction the vertical slits  358  will permit the rigid tubing  190  to bear frictionally against one of the first  126 , second  130 , third  134  and fourth  138  mounting rails. When the threaded collar  374  is rotated in a second  382 , loosening direction the vertical slits  358  will permit the rigid tubing  190  to slide over one of the first  126 , second  130 , third  134  and fourth  138  mounting rails, permitting vertical adjustment of the second enclosure  98 .  
         [0060]    In still another variant of the invention, as illustrated in FIGS. 4, 10 and  11 , the securing strap assembly  60  for securing the crib  10  to a parental bed  62  further includes a strap member  128  of a length greater than twice a width  132  of the parental bed  62  having a first end  136  and a second end (not shown). A resistance plate member  140  is provided that has at least two slots  144  vertically aligned and centrally located through which the strap member  128  is threaded such that the first end  136  and the second end are substantially equidistant from the plate member  140 . A strap member receiving means  148  is fixedly attached to the first side wall  86  and second side wall  90  of the crib  10 . Attachment cooperation means  152  are slidably engaged near the first end  136  and near the second end of the strap member  128  for reversible connection to the strap member receiving means  148 . Means  156  for adjusting a length of the strap member  128  and fixedly tightening it after connecting the attachment cooperation means  152  to the strap member receiving means  148  are provided. The strap member  128  is properly positioned when located under a mattress  422  of the parental bed  62  and held in place by the resistance plate member  140  located vertically at a side  426  of the parental bed  62  opposite placement of the crib  10  and the strap member  128  is tightened so the crib  10  is held fast to the parental bed  62 .  
         [0061]    In yet another variant, as illustrated in FIG. 11, the securing strap assembly  60  for securing the crib  10  to a parental bed  62  includes first  430  and second (not shown) guide slots. The guide slots  430  are sized, shaped and located upon the first  86  and second  90  side walls of the crib  10  to constrain the strap member  386  adjacent its first end  394  and its second end, thereby more securely holding the crib  10  to the parental bed  62 .  
         [0062]    In yet a further variant of the invention, as illustrated in FIGS. 12 and 15, a crib convertibly adapted for use as a co-sleeper  10  includes a rigid first enclosure  66 . The first enclosure  66  has an open top  70 , a floor  74 , a front wall (not shown), a back wall  82 , a first side wall  86  and a second side wall  90 . The front wall is removably mounted to the crib  10 . The first enclosure  66  is of the first predetermined height  34 . A second enclosure  98  is provided. The second enclosure  98  has an open top  102 , a floor  106 , a front  110 , a back  114 , a first side  118  and a second side  122 . First  438 , second  442 , third  446  and fourth  450  mounting rails are provided. Each of the rails  438 ,  442 ,  446 ,  450  has a first end  454  and a second end  458 . The second  442  and fourth  450  mounting rails are located adjacent to and bear upon the back wall  82  of the first enclosure  66 .  
         [0063]    A rear upper connecting rail  462  is provided. The rear rail  462  has a first end  466  and a second end  470  and is removably attached at its first end  462  to the first end  454  of the second mounting rail  442  and removably attached at its second end  466  to the first end  462  of the fourth mounting rail  450 . A first side upper connecting rail  474  is provided. The first side rail  474  has a first end  478  and a second end  482  and is removably attached at its first end  478  to the first end  454  of the second mounting rail  442  and removably attached at its second end  482  to the first end  454  of the first mounting rail  438 . A second side upper connecting rail  486  is provided. The second side rail  486  has a first end  490  and a second end  494  and is removably attached at its first end  490  to the first end  454  of the fourth mounting rail  450  and removably attached at its second end  494  to the first end  454  of the third mounting rail  446 .  
         [0064]    Four mounting feet  498  are provided. Each of the feet  498  is sized and shaped to attach to the second end  458  of one of the first  438 , second  442 , third  446  and fourth  450  mounting rails and to grip frictionally the floor  74  of the first enclosure  66 . Means  150  are provided for adjustably mounting the second enclosure  98  to the first  438 , second  442 , third  446  and fourth  450  mounting rails within the first enclosure  66  at at least one predetermined distance  58  from the top  70  of the first enclosure  66 .  
         [0065]    As illustrated in FIG. 10, a securing strap assembly  60  is provided for securing the crib  10  to a parental bed  62 . When the front wall  78  is removed from the crib  10 , the second enclosure  100  is mounted within the first enclosure  66 , the securing strap assembly  60  is properly positioned and the crib  10  is secured to the parental bed  62 , the crib  10  will serve as a co-sleeper.  
         [0066]    In still a further variant, as illustrated in FIGS. 2, 13 and  14 , a crib convertibly adapted for use as a co-sleeper  10  also includes at least one pair of tensioning devices  502 . The tensioning devices  502  have a threaded rod  506  with a first end  510 , a second end  514 , and an attachment plate  518 . The plate  518  is orthogonaly mounted to the first end  510  of the threaded rod  506 . At least one pair of threaded orifices  522  passing orthogonaly through at least two of the second  442  and fourth  450  mounting rails and the first  438  and third  446  mounting rails is provided. The orifices  522  are sized, shaped, and located to receive threadedly the second end  514  of the threaded rods  506  of the tensioning devices  502  such that the threaded rods  506  are collinear. When the threaded rods  506  of the tensioning devices  502  are rotated outwardly from two of the second  442  and fourth  450  mounting rails and the first  438  and third  446  mounting rails, the attachment plates  518  will bear against the first side wall  86  and the second side wall  90  of the crib  10 , thereby stabilizing the second enclosure  98  within the crib  10 .  
         [0067]    In yet another variant, as illustrated in FIG. 14, the tensioning device  502  further includes a stabilizing point  526 . The point  526  is collinear with the threaded rod  506  and mounted orthogonaly to the attachment plate  518 , thereby preventing movement of the second enclosure  100  with respect to the crib  10 .  
         [0068]    In still a further variant of the invention, as illustrated in FIG. 16, a second enclosure  98  for use with an existing crib  530  is provided, along with a securing strap assembly  58  for securing the crib  530  to a parental bed  62 . Mounting rails  126 ,  130 ,  134 ,  138  for the second enclosure  98  are secured to the first  86  and second  90  side walls of the crib  530 .  
         [0069]    In yet another variation, as illustrated in FIGS. 12 and 17, for use with an existing crib  530 , mounting rails  438 ,  442 ,  446 ,  450  for the second enclosure  98  are free-standing and are removably attached together with a rear upper connecting rail  462 , a first side upper connecting rail  474  and a second side upper connecting rail  486 . The second  442  and fourth  450  mounting rails are located adjacent to and bear upon a back wall  532  of the existing crib  530 . A securing strap assembly  58  for securing the crib  530  to the parental bed  62  is also provided. In still another variant, at least one pair of tensioning devices  502  is provided. In still another variation, tensioning devices  502  bear upon first  536  and second  540  side walls of the existing crib  530  and serve to stabilize the second enclosure  98  within the existing crib  530 . In a final variant, as illustrated in FIG. 14 the tensioning devices  502  include stabilizing points  526  to prevent movement of the stabilizing devices  502  with respect to the crib  530 .
An adjustable co-sleeper nest is described. The invention, in a first embodiment, comprises a baby crib having a removable front wall and four supporting rails attached to the back and side walls of the crib structure. A platform having a back wall, first and second side walls, and a reduced height front wall formed of flexible material is adjustably suspended from the supporting rails. A mattress pad is supported upon the platform structure within the walls of the platform. The platform and mattress pad extend beyond the side walls of the crib for a predetermined distance so that the mattress will fit snugly against the edge of a parental bed. Various means are provided for adjusting and securing the height of the co-sleeper platform. Strapping means are provided for securing the crib to the side of the parental bed. In a second embodiment, the co-sleeper nest is free-standing within an existing crib, bearing against the rear wall of the crib. Means are provided for securing the crib to the side walls of the crib as well as for strapping the crib to the parental bed. The free-standing embodiment is designed to collapse for storage and transport.