Abstract:
The apparatus is a height adjustment assembly for a child&#39;s changing table with support tubes inserted into sockets at the top of a supporting structure such as a play yard. A height adjustment fixture external to the support tubes rests on top of the supporting structure and has a vertical series of recesses such as slots or holes and a ring through which the changing table&#39;s support tube slides. The changing table has an attached latching device that locks into the recesses to hold the table at several heights above the supporting structure. Alternate embodiments include a structure in which the height adjustment fixture contains the latching device and the recesses are in the changing table.

Description:
[0001]     This application is based upon U.S. Provisional Patent Application Ser. No. 60/535,083 filed Jan. 8, 2004. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     This invention deals generally with changing tables for infants, and more specifically with a height adjustment apparatus for a changing table installed on top of a structure such as a child&#39;s play yard.  
         [0003]     Children&#39;s playpens, now more often called play yards, are a commonly available accessory for use with infants and small children. It is not at all unusual for parents to take a folding play yard along on a trip or visit in order to provide a space for the child to play and sleep. There is also another accessory for children that is just as vital, but not taken out of the child&#39;s home as frequently. That is a changing table or bassinet.  
         [0004]     However, there are now available some changing tables that simply attach to a play yard and therefore are not at all difficult to take out of the home along with the play yard. Most of these tables take advantage of the height of the sides of the play yard and are attached to the top of the play yard sides.  
         [0005]     U.S. Pat. No. 5,339,470 to Shamie discloses one such combination playpen and changing table that re-hangs the bottom of the playpen from short straps attached to the horizontal top rails of the playpen in order to provide a somewhat higher surface for changing the child. U.S. Pat. No. 5,553,336 to Mariol uses a different approach by providing a complete assembly that resembles a second layer of the play yard that fits into wells on the top four corners of the play yard. Another type of changing table available is supported off one corner of a play yard, and it is rotated beyond the walls of the play yard when not in use.  
         [0006]     The problem with all such arrangements is that they furnish only one height for the changing table, and that one height, which is keyed to the existing height of the play yard walls, is usually too low for an adult to use with comfort, because adults of average height must bend down to the level of the changing table. Furthermore, any changing table with a single pre-designed height can not possibly suit all adults.  
         [0007]     It would be very beneficial to have an uncomplicated changing table that attaches to the top of a play yard and is easily adjustable to accommodate adults of different heights.  
       SUMMARY OF THE INVENTION  
       [0008]     The present invention provides a simple structure for attaching a height adjustable changing table to the top of a play yard or other structure. To accept the support structure of the changing table, the play yard or other supporting structure requires only that a socket with an open top be attached to an upper edge of the supporting structure. It is probably most convenient and most stable if two sockets are mounted near two upper corners of a play yard. A vertical support for the changing table then fits into each socket, and both the changing table and the entire height adjustment assembly are attached to the changing table without any further modification to or addition of internal structures for either the play yard support or the changing table support.  
         [0009]     The changing table support is attached to the changing table structure by conventional means such as rivets or screws, and the height adjustment assembly fits within the changing table structure, but the height adjustment assembly is external to both the support on the changing table and the socket on the play yard.  
         [0010]     The main part of the height adjustment assembly of the preferred embodiment is a height adjustment fixture that contains three sections. One section is a coupling, which in the preferred embodiment is a ring that is horizontally oriented as it fits around the changing table vertical support just below the location where the changing table support protrudes out of the changing table. An extension oriented parallel to the axis of the coupling ring is attached to and slightly offset from the coupling ring and contains the other two sections of the fixture. The second section is a cylindrical tube, the axis of which is parallel to the axis of the coupling ring and the axis of the changing table support. This tube fits within the changing table, and into a cylinder integrated into the changing table structure. The tube slides within the cylinder to maintain alignment between the changing table and the third section which is a rack assembly.  
         [0011]     The rack assembly is a linear strip attached to the outside of the cylindrical tube, with the linear strip containing a series of slots and separating lands so that it resembles the rack of a gear and rack assembly. In one embodiment of the invention, a gear mounted on the changing table engages the lands, and turning the gear raises or lowers the changing table.  
         [0012]     The preferred embodiment of the invention uses a spring loaded lever that engages the slots, but permits the height of the changing table to be manually lifted or lowered when the lever is pushed to move its latching end out of the slots.  
         [0013]     The particular benefits of the height adjustment assembly of the invention are simple structure, inexpensive manufacturing, ease of use, and attachment to any supporting structure with nothing more than the addition of one or two tubular sockets at the top of the supporting structure. In particular, there is no requirement to put holes in any of the tubular structure of the supporting structure or install complex locking mechanisms within the supports of either the changing table or the supporting structure to which it is attached. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]      FIG. 1  is a partial sectional side view of the height adjustment assembly of the preferred embodiment of the invention installed within a changing table that is shown atop a play yard.  
         [0015]      FIG. 2  is a perspective view of the height adjustment fixture of the preferred embodiment of the invention of  FIG. 1 .  
         [0016]      FIG. 3  is a side view of an alternate embodiment of the height adjustment assembly of the invention.  
         [0017]      FIG. 4  is a perspective view of another alternate embodiment of a height adjustment assembly of the invention.  
         [0018]      FIG. 5  is a perspective view of the coupling and latch assembly of the alternate embodiment of  FIG. 4 .  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0019]      FIG. 1  is a partial sectional side view of height adjustment assembly  10  of the preferred embodiment of the invention installed within changing table  12  shown atop play yard  14 , and  FIG. 2  is a perspective view of height adjustment fixture  11  of the preferred embodiment of the invention. The view of height adjustment fixture  11  in  FIG. 2  is from the opposite side of the view shown in  FIG. 1  in order to better show the structure of height adjustment fixture  11 .  
         [0020]     Height adjustment fixture  11  of  FIGS. 1 and 2  includes a series of at least two slots  16  alternating with lands  18  which, when installed within changing table  12 , are aligned in a vertical orientation. Slots  16  and lands  18  are formed on support structure  20 , and tube  22  is attached to support structure  20  on surface  24  opposite lands  18 . Height adjustment fixture  11  also includes coupling ring  26  which is attached to support structure  20  at the end of support structure  20  remote from opening  21  of tube  22 . Coupling ring  26  is attached to support structure  20  at surface  28  which is the surface most remote from lands  18 , so that axis  27  of coupling ring  26  is parallel to axis  23  of tube  22  and to axis  31  of changing table support  30 , and coupling ring  26  has no interfering structures on either side of it along its axis  27 .  
         [0021]     As shown in  FIG. 1 , the clearance on both sides of coupling ring  26  permits height adjustment fixture  11  to be installed within changing table  12  and perform its function although it need not be permanently attached to changing table  12 . For changing table  12  to accommodate height adjustment fixture  11 , changing table  12  itself needs three structures. One is changing table support  30  which can be a basic tube structure that is used to attach most accessories to supporting structures such as play yard  14 . Changing table support  30  is attached to changing table  12  by any conventional means such as hole  32  and fasteners  34 .  
         [0022]     The attachment of changing table  12  to play yard  14  is also conventional in that holding fixture  36  with socket  38  is attached to play yard  14  at an upper location, such as adjacent to a corner where horizontal rail  40  is attached to vertical support  42 . Socket  38  in holding fixture  36  can then accept any simple rod or tube, such as changing table support  30 , as long as the tube is of smaller diameter than socket  38 . However, such simple holders for accessory structures provide no height adjustment since the lower part of the accessory structure would merely sit upon holding fixture  36 .  
         [0023]     The simple structure of height adjustment fixture  11  furnishes a vital part of the height adjustment with no modification of either support  30  or holding fixture  36 . In the preferred embodiment shown in  FIG. 1 , height adjustment fixture  11  is shown installed in changing table  12 . This is accomplished by slipping coupling ring  26  over changing table support  30  so that the bottom surface  29  of coupling ring  26  rests upon holding fixture  36 . Tube  22  of height adjustment fixture  11  then fits into a socket concentric with tube  22  within changing table  12  and aids in aligning height adjustment fixture  11  with changing table  12 . Tube  22  also holds spring  44 . Spring  44  is a compression spring, which is shown with dashed lines in  FIG. 1  and inserted within tube  22  in  FIG. 2 , has its upper end against an inner surface of changing table  12 , and serves to overcome any friction between tube  22  and its socket. Spring  44  thus assures that height adjustment fixture  11  continues to rest on holding fixture  36  of play yard  14  as changing table  12  is raised.  
         [0024]     In regard to stability and alignment, it is worthwhile to note that the most typical installation of height adjustment assembly  10  of the present invention is in pairs with one on each of two supports  30  located at opposite ends of changing table  12 . The two supports are installed into holding fixtures  36  located near adjacent corners of play yard  40 . Such an arrangement provides an appropriate length for the changing table and does not require any locking apparatus to prevent supports  30  from rotating within fixture  36 .  
         [0025]     Height adjustment assembly  10  requires one more device attached to changing table  12 . That is lever  46  which holds changing table  12  in one of the height positions provided by slots  16 . Lever  46  rotates around pivot point  48  when lever handle  50  is pushed toward lands  18 , and as lever  46  rotates, latch  52  moves out of the slot  16  in which it is lodged. This permits changing table  12  to be manually raised or lowered. When lever handle  50  is released, spring  54  forces lever handle away from slots  16 , thus moving latch  52  into an available slot  16 . Since height adjustment assemblies are typically installed near the ends of changing table  12 , and when pushing lever handle  50  the user&#39;s hands are in contact with the underside of changing table  12 , it is not at all difficult to operate two lever handles simultaneously and also raise or lower changing table  12 .  
         [0026]      FIG. 3  is a side view of alternate embodiment  60  of the height adjustment assembly of the invention. Support structure  20 , tube  22 , and coupling ring  26  of height adjustment assembly  60  are identical to and serve the same function as the same parts of height adjustment fixture  11  in  FIGS. 1 and 2  so they are identified by the same numbers. The difference in height adjustment assembly  60  is in the recess and land structure. Alternating slots  62  and lands  64  of height adjustment assembly  60  are constructed to operate as rack  61  in conjunction with gear  66  so the spacing of lands  64  must match the spacing of teeth  68  on gear  66 . The height adjustment is then accomplished by rotating gear  66  in the appropriate direction.  
         [0027]     Gear  66  is mounted upon and attached to the changing table (not shown in  FIG. 3 ) in a manner similar to lever  46  of  FIG. 1 , so that as gear  66  literally climbs up rack  61 , the changing table is raised. This eliminates the requirement to manually lift the changing table to adjust the height.  
         [0028]     Gear  66  can be rotated by any conventional means. One rotating device is shown in  FIG. 3 . Knob  70  is mounted on surface  72  of the changing table (not shown) and drives gear  66  by conventional linking means  74  either directly or through a reduction drive. One requirement for any height adjustment assembly is that it have some sort of latching device to prevent the changing table from moving down with increased weight. The latching device is provided for height adjustment assembly  60  at knob  70 . Knob  70  includes latch  76  that is pushed outward by spring  78  and moves into slots  80  to prevent both knob  70  and gear  66  from turning unless latch  76  is pulled into knob  70  by moving tab  79  against spring  78 . Latch  76  is only one of many conventional devices to permit locking knob  70 . Another such device is a tab on a spring loaded shaft that mates with slots around the shaft unless moved axially to disengage the tab from the slots for turning the shaft.  
         [0029]      FIG. 4  is a perspective view of another alternate embodiment of a height adjustment assembly  84  of the invention with only partial structure  86  of the changing table shown. Similar to the changing table  12  of  FIG. 1 , changing table structure  86  has changing table support  88  attached so that support  88  can be installed into a holding fixture (not shown) on the supporting structure upon which it will be supported. The essential difference between height adjustment assembly  84  and height adjustment assembly  10  of  FIG. 1  is that latches  90  are integrated with coupling  92  into coupling and latch assembly  94 . Coupling and latch assembly  94  thus minimizes the number of parts and simplifies the design of changing table structure  86 . All that is required within changing table structure  86  are socket  96  (shown with invisible lines) within which coupling and latch assembly  94  fits and holes  98  to mate with latches  90 . As with height adjustment assembly  10  of  FIG. 1 , height adjustment assembly  84  permits changing table support  88  to slide within coupling  92  when latches  90  are depressed, and changing table structure  86  and the entire changing table are raised as coupling and latch assembly  94  slides within socket  96 . Releasing latches  90  then permits them to mate with other holes  98  and hold the changing table at a different height.  
         [0030]      FIG. 5  is a perspective view of coupling and latch assembly  94  of height adjustment assembly  84  of  FIG. 4 . Latches  90  are mounted upon spring  100  so that simply pressing latches  90  in toward the center of support structure  102  flexes spring  100  and releases the latches from holes  98  in changing table structure  86  ( FIG. 4 ). This simple mechanism on support structure  102  eliminates the need for an external latching mechanism on the changing table. It should be understood that the rectangular configuration of support  102  and the use of pairs of latches  90  and twin holes  98  ( FIG. 4 ) are not vital to the function of height adjustment assembly  84 , and many other configurations of these structures can be used.  
         [0031]     The invention thus provides a convenient and easily manufactured height adjustment for a changing table used in conjunction with a play yard or any other supporting structure, and it requires no complex modification of the supporting structure or the changing table supports because the height adjustment assembly is external to those supports.  
         [0032]     It is to be understood that the form of this invention as shown is merely a preferred embodiment. Various changes may be made in the function and arrangement of parts; equivalent means may be substituted for those illustrated and described; and certain features may be used independently from others without departing from the spirit and scope of the invention as defined in the following claims. For example, springs other than leaf spring  54  as shown can be used, or height adjustment fixture  11  can use holes or any other type of recesses within support structure  20  instead of slots  16 , and the latch can be a spring loaded retractable pin instead of pivoting latch  52 . Furthermore, neither the changing table support nor the coupling of the height adjustment assembly need to have cylindrical cross sections, nor the coupling even be a ring, as long as they mate, can be assembled together, and the support can move within the coupling.