turning now to the drawings , fig1 schematically illustrates the modular playpen apparatus of the present invention , generally referenced as 10 . the apparatus includes : a plurality of vertical uprights 20 ; a series of substantially rectangular side panels 30 ; a plurality of horizontal cross bars 40 ; floor pads 50 and a center support post 60 underneath the floor pads ( shown in fig6 ). referring specifically to fig1 vertical uprights 20 are positioned a sufficient distance from each other in order to allow for a side panel 30 to fit between them . each upright 20 is a round post comprised of plastic or other suitable material , approximately 2 feet high . each upright 20 has a slot or groove 21 running along its length . this can be seen more clearly in fig2 and fig3 . the vertical side of each side panel 30 slides into one of the grooves 21 of a vertical upright 20 . each upright 20 is joined to two side panels 30 to form the enclosure shown in fig1 . although the playpen 10 can be configured as a square , as shown in fig1 there are an infinite number of configurations that can be formed by either matching different grooves 21 of different uprights 20 with different side panels 30 or by adding on additional panels 30 , uprights 20 and cross bars 40 . each upright 20 has four identical grooves 21 running along its length , in order to receive up to four side panels 30 . in an alternate embodiment , each upright 20 can have more than four grooves . this would allow for connection to more side panels 30 and cross bars 40 thereby creating many more playpen configurations . each horizontal cross bar 40 is of approximately the same length as each side panel 30 and provides structural support to the bottom , horizontal side of each side panel 30 . each end of the horizontal cross bar 40 is inserted into a vertical upright 20 , just below the bottom of groove 21 . fig3 shows the inter - connection of a side panel 30 with a vertical upright 20 . the groove 21 running down the length of the vertical upright 20 is approximately 1 / 2 - inch deep and sized to receive a vertical edge of a side panel 30 . the groove 21 does not extend the entire length of the upright 20 but terminates near the bottom to allow for the cross bar 40 to be inserted into the upright 20 . in the preferred embodiment , the groove 21 begins at the top of the vertical upright 20 and terminates near the bottom of the vertical upright 20 , above where the cross bar 40 meets the upright 20 . fig4 shows a top view of the upright - side panel connection . two side panels 30 can be slid from the top of an upright 20 within one of the grooves 21 . the length of the groove 21 corresponds to the length of each side of a side panel 30 allowing for each vertical side of a side panel 30 to be slidably secured to an upright 20 . fig6 depicts a top view of the square - shaped playpen 10 of fig1 and shows the interconnection of the side panels 30 with the grooves 21 in each vertical upright 20 . also shown is the center post 60 as it protrudes through and between the floor pads 50 . the cut - outs 51 in each corner of the floor pads 50 allow for the center post 60 to protrude between the pads thereby providing a contiguous inner surface . the top covering of the center post 60 is comprised of the same material that comprises the floor pad 50 . in this way , the floor of the playpen 10 forms a uniform surface . the actual inter - connection of the panel and upright can occur in a variety of ways . one method can be to provide a notch or downward protrusion in the bottom of the edge of the side panel 30 . this protrusion would be inserted into the upright 20 first until the protrusion reaches the terminus of the groove 21 . the remaining portion of the edge of the panel 30 can then slide into the remaining portion of the groove 21 until the panel 30 is secured therein . other methods to connect the panels 30 to the uprights 20 may include providing panels with a spring mechanism on one or both ends , a small horizontal flange on the top corner of the panel preventing the panel from dropping down into the groove , or a retractable knob similar to those used to secure accordion closet doors within closet enclosures , located at the bottom corner of each panel used in conjunction with the flange . each side panel 30 is substantially rectangular or square . its sides are generally of plastic and surround a see - through nylon mesh or netting made of standard nylon material . this allows for the young child or infant within the playpen enclosure to observe the events outside of the playpen . each side panel 30 can be easily removed by lifting it up and out of the groove 21 of the vertical uprights 20 . no tools are necessary . the easy removal of the side panels 30 does not belie the fact that the panel - upright connection is sturdy and a young child within the enclosure could not remove a panel by himself . fig5 shows the horizontal cross bar 40 of the present invention in greater detail . each horizontal cross bar 40 has a flat upper longitudinal surface 41 and a rounded lower longitudinal surface 42 . the flat upper longitudinal surface 41 has a thin protruding edge 43 running along its entire length . this edge 43 bisects the flat upper longitudinal surface 41 , thereby creating an inner and outer upper longitudinal surface . as can be seen clearly in fig5 the inner portion of the upper longitudinal surface 41 provides support to the outer edge of the floor pad 50 . for safety and aesthetic purposes , the top of the edge 43 remains below the top surface of the floor pad 50 thereby preventing the appearance of the edge within the interior of the playpen 10 . the lower horizontal side of the side panel 30 rests on top of the protruding edge 43 . each floor pad 50 is made of a sturdy plastic backing material topped by a vinyl - covered cushion , such as polyurethane foam . to accommodate the vertical uprights 20 , the floor pads 50 have an arc - shaped cut - out 51 at each of its corners . therefore , when a floor pad 50 abuts against an upright 20 or center post 60 , a contiguous surface is created , and the pads do not overlap . fig6 shows a top view of the square playpen 10 of fig1 . the cut - outs 51 can be seen wherever a floor pad 50 is positioned next to an upright 20 or center post 60 . these cut - outs 51 allow for the floor pads 50 to fit snugly within the enclosure without any spaces which may cause injury to the child . the floor pads 50 are sized such that each pad will fit snugly between the vertical uprights 20 and the protruding center post 60 . each vertical upright 20 receives an end of a cross bar 40 . in the preferred embodiment , each upright 20 has a notch of approximately the same shape as the t - shaped end 44 of cross bar 40 , below the terminus of groove 21 to receive one end of the cross bar 40 . however , other connection means may be employed to join the upright and cross bar . fig7 shows the center post 60 and its connection to four horizontal cross bars 40 . the center support post 60 is positioned substantially underneath the floor pads 50 , within the interior of the playpen 10 . the top portion of the center post 60 is covered with the same vinyl cushion material as that of the floor pads and protrudes up and between the void created by the cut - outs 51 . the four horizontal cross bars 40 connect to the center support post 60 via the same means as the cross bars 40 are connected to the uprights 20 around the perimeter of the playpen 10 , namely , the insertion of the t - shaped end 44 of the cross bar 40 into a notch in the center support post 60 . once again , other standard connecting means could be employed . the center post 60 , therefore , receives one end of the four cross bars 40 , and the four centermost uprights 20 around the perimeter of the playpen 10 receive the other end of the cross bar 40 . fig6 shows the four ( 4 ) centermost uprights around the perimeter of the playpen 10 receiving three ( 3 ) horizontal cross bars 40 each , ( two along the perimeter of the playpen and a third underneath the floor pads 50 ), while the four ( 4 ) corner uprights receive two ( 2 ) horizontal cross bars 40 . fig6 also shows the cut - outs 51 of the floor pads 50 allowing for the center post 60 to protrude between the floor pads 50 . the center support post 60 , in conjunction with the cross bars 40 , does not support the side panels 30 , but instead serves to provide support to the playpen 10 from underneath the floor pads 50 while forming a connection between the sides of the playpen 10 . the center post 60 is not noticeably discernable as only its top protrudes between the pads and it is made of the same material as the floor pads . in the preferred embodiment of the present invention , a total of eight uprights 20 , eight side panels 30 , four floor pads 50 , twelve cross bars 40 and one center support post 60 are used to create a square playpen enclosure , approximately 3 feet by 3 feet . however , as can be seen in fig8 - 11 , the components can also be reconfigured to produce an approximately 41 / 2 foot by 11 / 2 foot rectangular enclosure , or other non - conventional configurations , to conform to the contour of different sized rooms or area constraints . additional side panels , uprights and cross bars can be added to expand and alter the shape of the enclosure to adapt to available space . as shown in fig8 the playpen 10 can be configured around objects in the room . as seen in fig9 side panels 30 can be inserted into the uprights 20 to create separate enclosures . the need for a separate enclosure may be for a sleeping child who needs to be separated from the other children , or to store children &# 39 ; s shoes or extra clothing while the child plays in the larger , adjacent enclosure . a long , rectangular version of the playpen 10 may be used to near a pool , as seen in fig1 . for example , if others are in the pool , and there is not sufficient space to fit a standard playpen , the playpen 10 of the present invention can be configured to &# 34 ; wrap around &# 34 ; and follow the perimeter of the pool . this would allow the child to remain safely in the playpen , yet follow the activity in the pool . with a small amount of creativity , parents can create a variety of entertaining and practical configurations of the playpen 10 . the present invention could be used in various rooms in the home , outside in the backyard , in day - care centers , or taken on trips . the ease at which the side panels can be slid out of the elongated grooves along the length of the uprights make the present invention easy to disassemble and reassemble without the use of tools . furthermore , the horizontal cross bars can be removed from the vertical uprights with little difficulty . the entire playpen can be disassembled and transported in a travel bag . further embodiments can offer an attachable covering or canopy if the playpen were to be used outside , in inclement weather . the instant invention has been shown and described herein in what is considered to be the most practical and preferred embodiment . it is recognized , however , that departures may be made therefrom within the scope of the invention and that obvious modifications will occur to a person skilled in the art .
a modular playpen for infants and young children comprising five basic parts including a plurality of substantially rectangular side panels ; a plurality of vertical uprights slidably affixed to each end of a side panel via a longitudinal groove running the length of each vertical upright , thereby forming an enclosure ; floor pads positioned within the enclosure ; a series of horizontal cross bars removably engaged to the lower portion of each vertical upright thereby providing support to the playpen ; and a central post positioned beneath the floor pads to provide additional support to the floor pads . the modular playpen can be reconfigured in a variety of shapes to conform to space constraints , and can be assembled , disassembled and reassembled again quickly without the use of tools .