referring now to the drawings for the purposes of illustrating the present preferred embodiment of the invention only and not for purposes of limiting the same , fig1 - 6 show an embodiment of the toy staircase apparatus generally designated as 8 . the toy stairway 8 includes a single elongated resilient stringer 10 having generally straight generally parallel side edges 21 and 23 which is bent to form elongated first and second strip sections or elongated side rails 12 and 14 which are positioned in confronting spaced relationship with one another and define a spaced area between them . the resilient stringer 10 is formed of a flexible yet strong material that can be coiled into a compact cylinder to facilitate packaging , shipping , merchandising and storing . the material of the stringer 10 must be resilient in that it is capable of being coiled into a tight coil but will resume its uncoiled form when released . the stringer 10 is preferably plastic , but the stringer 10 may also be formed of heavy cardboard , flexible sheet metal , or other such material . when uncoiled and assembled , the flexible stringer 10 forms two side rails 12 and 14 of the stairway 8 . as shown in fig3 when uncoiled and unassembled , the flexible stringer 10 is a continuous elongated strip member , and side rails 12 and 14 become first and second portions or first and second elongated strip sections of the stringer 10 . the stringer 10 is preferably approximately 3 inches wide , 84 inches long and 0 . 040 inches thick , and coils into a cylinder approximately 5 inches in diameter and 3 inches tall , but is not limited to these particular dimensions . the length of the stringer 10 depends on the desired length and number of steps on the toy stairway 8 . eighty four inches is the preferred length for approximately six steps . the toy stairway 8 has a plurality of rigid substantially l - shaped step pieces 20 , each of which comprises a tread portion 22 formed integral at a substantially right angle with a riser portion 24 , disposed between the side rails 12 and 14 . the step pieces 20 are formed of strong material , such as plastic , heavy cardboard , flexible sheet metal , or other such material . the step pieces 20 are proportioned to fit in the spaced area between the side rails 12 and 14 to form a continuous stairway 8 . the treads 22 are approximately 5 inches wide , 5 inches deep , and 0 . 060 inches thick . the risers 24 are approximately 5 inches wide , 3 inches high , and 0 . 060 inches thick . the treads 22 and risers 24 can be constructed of different size and shape to provide a staircase for use with different size spring toys , to add a different number of steps in a given space , and / or to provide a different walking motion , as discussed below . although it is preferred that the risers 24 be as wide as the treads 22 and reach from one tread 22 to the next , it is not necessary that the risers 24 be so shaped and sized . when placed in the operable position , the side rails 12 and 14 of the flexible stringer 10 have numerous pairs of horizontal slots 16 and vertical slots 18 formed therein at right angles to one another . the treads 22 are formed with integral tabs 26 ( fig2 ) which interlockingly engage the horizontal slots 16 formed in the side rails 12 and 14 of the flexible stringer 10 so that the treads 22 are connected to the side rails 12 and 14 . the risers 24 of the step pieces 20 are formed with integral tabs 28 ( fig2 ) which interlockingly engage the vertical slots 18 formed in the side rails 12 and 14 of the flexible stringer 10 so that the risers 24 are connected to the side rails 12 and 14 . various combinations of the integral tabs 26 and 28 of the treads 22 and the risers 24 , respectively , and the horizontal slots 16 and vertical slots 18 , respectively , of the side rails 12 and 14 may be eliminated , although this may produce some loss of rigidity of the toy stairway 8 . the step pieces 20 are thus releasably connected to the side rails 12 and 14 of the flexible stringer 10 in this manner . other methods of connecting these materials to one another are well known in the art , and can be used to connect the step pieces 20 to the side rails 12 and 14 of the stringer 10 . step pieces 20 may be permanently attached to the side rails 12 and 14 after assembly through the connection of the interlocking tabs 26 and 28 with the slots 16 and 18 , respectively , or using well known attachment methods such as glue or other interlocking parts . however , such attachment limits disassembly and storage capability . the toy stairway 8 is assembled by first uncoiling the stringer 10 . the stringer 10 is then bent in the middle of its lengthwise direction to form both side rails 12 and 14 in a confronting spaced relationship . the tabs 26 and 28 on one side of one step piece 20 are fit into a horizontal slot 16 and a vertical slot 18 , respectively , in either side rail 12 or 14 . the tabs 26 and 28 on the opposite side of the step piece 20 are then fit into the corresponding horizontal slot 16 and vertical slot 18 , respectively , of the other side rail 12 or 14 . the remaining step pieces 20 are then similarly attached between the side rails 12 and 14 of the stringer . to use the toy stairway 8 , the curved end of the stringer 10 can be leaned against typical household objects of suitable size such as a chair or a coffee table . the toy stairway 8 is then in position to facilitate the &# 34 ; walking &# 34 ; motion of the spring toy . the spring toy may be &# 34 ; walked &# 34 ; down the toy stairway 8 by setting it on the top step , grasping the top of the spring toy , pulling it over and placing it on the next lower step . the lower portion of the spring toy will follow the upper portion over to the lower step , thus becoming the top portion . the momentum of traveling to the lower step , however , will carry the new upper portion over and down to the next step . this will continue for each step , with the spring toy traveling end over end down each step until it reaches the level surface such as the floor on which the toy stairway 8 is placed . spring toys are made in a variety of sizes . one typical spring toy size is approximately 31 / 2 inches in diameter and 31 / 2 tall . in effectuating the &# 34 ; walking &# 34 ; motion of a spring toy down a stairway , the tread and the riser must be of a certain size and the riser must be of a proper ratio to the tread for the spring toy to walk properly . the tread must be of a certain minimum width and depth so that the spring toy has sufficient horizontal surface on which to land . the minimum width and depth are approximately the width and depth of the spring toy itself . similarly , if the tread is too large , the spring toy will not naturally fall to the next lower tread , but will instead fall over onto the same tread and come to a rest . this maximum size depends also on the height of the riser , but generally is about three times the width of the spring toy . if the tread is too large compared to the riser , then the spring toy will not gain enough momentum to properly walk down the stairs , and will come to rest on the tread . if the tread is too small compared to the riser , then the spring toy will gain too much momentum , and the spring toy will overshoot the tread , disrupting the walking motion . the tread to riser ratio may be reduced or increased within the operable range to increase or decrease the speed of the walking motion . for a standard size spring toy , we prefer that the tread be approximately 5 inches deep and approximately 5 inches wide , and that the riser be approximately 3 inches high and approximately 5 inches wide , although other sizes and ratios of the tread and riser may work equally as well . for smaller spring toys , the tread 22 and the riser 24 may be made smaller , and for larger spring toys , the tread 22 and the riser 24 may be made larger . an additional advantage of the present embodiment is that the entire toy stairway 8 may be turned over ( not shown ) and used with a different size spring toy . when turned over , the treads 22 become risers and the risers 24 become treads . the new treads would then be approximately 3 inches deep and the new risers would be approximately 5 inches high . the smaller treads of this configuration would accommodate a smaller spring toy . as shown in fig6 the toy stairway 8 may be compactly packaged in a box 30 for shipping , merchandising or simply for storing . the toy stairway 8 is disassembled by reversing the order of assembly , as described above . the step pieces 20 are nested together and placed in the box 30 with the treads 22 facing down toward the bottom of the box 30 and the risers 24 facing one or more sides of the box 30 , although the package is most compact if all the risers 24 all face the same side of the box 30 . the flexible stringer 10 may then be coiled up and placed inside the box 30 on top of the step pieces 20 . the spring toy 32 then can be inserted inside the coiled up stringer 10 inside the box 30 . the length and width of the box will be slightly more than the dimensions of the tread 22 of the step pieces 20 , and the depth of the box 30 will be the width of the flexible stringer 10 plus the thickness of all the step pieces 20 . a typical box 30 for the preferred embodiment may be approximately 51 / 2 inches by 51 / 2 inches by 31 / 2 inches tall , and constructed of known packaging material , such as cardboard . an alternate embodiment of the present invention is partially shown in fig7 which shows the steps of the stairway formed of a one piece foldable step member 21 . the foldable step member 21 has a plurality of hingedly attached tread portions 22 &# 39 ; and riser portions 24 &# 39 ; which are formed of a rigid strong material , such as plastic or the like , and which are integrally connected by hinges 25 . each of the tread portions 22 &# 39 ; and riser portions 24 &# 39 ; are also integrally attached to form a continuous set of rigid steps . hinges 25 are typically formed of the same material as tread portions 22 &# 39 ; and riser portions 24 &# 39 ;, but are thinner and are flexible . this type of hinge mechanism is known as a &# 34 ; living hinge &# 34 ;. foldable step member 21 can be folded multiple times along hinges 25 into a stack for packaging , merchandising and storing purposes . if the tread portions 22 &# 39 ; and riser portions 24 &# 39 ; are of different dimensions , each set of tread portions 22 &# 39 ; and riser portions 24 &# 39 ; may be flattened into the same plane and the sets of tread portions 22 &# 39 ; and riser portions 24 &# 39 ; can be folded over and stacked on one another , and the thus unassembled toy stairway may be packaged in a box of corresponding rectangular cross - section ( not shown ) instead of a box of cross - section corresponding to the size of the tread portions 22 &# 39 ;. of course , other folding patterns and other - shaped boxes may be used . alternatively , multiple step members 21 of shorter length and fewer steps than the entire stairway may also be used . this step configuration may be combined with any of the stringer configurations disclosed herein . another alternate embodiment of the present invention is shown in fig8 . in this embodiment , a toy stairway 8 &# 39 ; is formed using two separate flexible stringers 12 &# 39 ; and 14 &# 39 ;, instead of a single flexible stringer 10 as shown in fig1 - 6 . like the flexible stringer 10 shown in fig1 - 6 , the flexible stringers 12 &# 39 ; and 14 &# 39 ; are formed of a flexible yet strong material , such as plastic , heavy cardboard , or flexible sheet metal , that can be coiled into cylinders which can be nested for packaging and merchandising purposes , but which will resume their uncoiled form when released . when uncoiled and assembled , the flexible stringers 12 &# 39 ; and 14 &# 39 ; form the side rails of the toy stairway 8 &# 39 ;. the step pieces 20 &# 39 ; may be the same as the step pieces 20 as shown in fig1 - 6 or step member 21 as shown in fig7 and contain horizontal and vertical tabs ( not shown ) which interlock into horizontal slots 16 &# 39 ; and vertical slots 18 &# 39 ;, respectively . this side rails configuration may be combined with any of the step configurations disclosed herein . another alternate embodiment of the present invention is disclosed in fig9 . in this embodiment , a toy stairway 8 &# 34 ; is formed using a one piece stringer 10 &# 34 ; that is foldable . the foldable stringer 10 &# 34 ; has hingedly connected fold sections 36 which are formed of a rigid strong material , such as plastic or the like , and which are integrally connected by the hinges 37 . the plurality of hinges 37 are formed integrally with fold sections 36 of plastic or like material that is typically thinner than fold sections 36 and flexible , or a &# 34 ; living hinge &# 34 ;. foldable stringer 10 &# 34 ; can be folded multiple times into a stack of the fold sections 36 for packaging and merchandising purposes . to use the foldable stringer 10 &# 34 ;, the fold sections 36 are unfolded , and then are folded at right angle hinges 38 to form side rails 12 &# 34 ; and 14 &# 34 ;. the step pieces 20 &# 34 ; are the same as the step pieces 20 as shown in fig1 - 6 or step member 21 as shown in fig7 and contain horizontal and vertical tabs ( not shown ) which interlock into the horizontal slots 16 &# 34 ; and vertical slots 18 &# 34 ;, respectively . the hinges 37 of foldable stringer 10 &# 34 ; are preferably located between each corresponding horizontal slot 16 &# 34 ; and vertical slot 18 &# 34 ; so that when in assembled position , the fold sections 36 are firmly held straight by the step pieces 20 &# 34 ; butted across the hinges 37 and the horizontal and vertical tabs ( not shown ) of the step pieces 20 interlocked into the horizontal slots 16 &# 34 ; and vertical slots 18 &# 34 ;, respectively . the foldable side rails 12 &# 34 ; and 14 &# 34 ; may also be made of two separate foldable side rails similar to the embodiment shown in fig8 . these stringer configurations may be combined with any of the step configurations disclosed herein . another alternate embodiment of the present invention is disclosed in fig1 . in this embodiment , step pieces 50 comprise only a tread portion and no riser , and have one or more tabs ( not shown ) formed integral to the step pieces 50 . numerous horizontal slots 46 are formed in the flexible stringer 40 in pairs , so that one or more tabs ( not shown ) on each side of the step pieces 50 may lock into the flexible stringer 40 on opposite sides . braces or support pieces 52 attached vertically underneath select step pieces 50 via integral tabs ( not shown ) formed in their sides that lock into vertical slots 48 formed in the flexible stringer 40 . the support pieces 52 each have a tab ( not shown ) formed in the top which fit into slots 53 formed near the front of step pieces 50 for added rigidity . this step configuration may be combined with any of the foregoing stringer configurations . fig1 discloses an alternate step design . step piece 50 &# 39 ; includes opposing flanges 51 and 51 &# 39 ;. the flange 51 is formed integral to the step piece 50 &# 39 ; at a right angle thereto in the upward direction . tabs 54 are formed integral to upward flange 51 at a right angle thereto facing away from the step piece 50 &# 39 ; the flange 51 &# 39 ; is formed integral to the step piece 50 &# 39 ; at a right angle thereto in the downward direction . tabs 54 &# 39 ; are formed integral to the downward flange 51 &# 39 ; at a right angle thereto facing away from the step piece 50 &# 39 ;. because the flanges 51 and 51 &# 39 ; are attached facing in opposite directions , step pieces 50 &# 39 ; can still be nested for compact packaging . with this step embodiment , the slots in the side rails ( not shown ) must be offset corresponding to the offset of tabs 54 and 54 &# 39 ;, respectively , so that the step piece 50 &# 39 ; is level . when tabs 54 and 54 &# 39 ; are engaged with slots in the side rails , the flanges 51 and 51 &# 39 ; are in full contact with the side rails , thus providing rigidity to the stairway , and no independent brace or support pieces are necessary . this step configuration may be combined with any of the foregoing stringer configurations . the principles , preferred embodiments and the mode of operation of the present invention have been described in the foregoing specification . however , the invention which is intended to be protected is not to be construed as limited to the particular embodiments disclosed . the embodiments are therefore to be regarded as illustrative rather than restrictive . variations and changes may be made by others without departing from the spirit of the present invention . accordingly , it is expressly intended that all such equivalents , variations and changes which fall within the spirit and the scope of the present invention as defined in the claims be embraced thereby .
a toy stairway is disclosed which may be used to play with a spring toy and which comprises elongated first and second collapsible side rails in confronting spaced relationship relative to each other , a plurality of rigid steps disposed between the first and second side rails , and means for releasably connecting the plurality of steps to the first and second side rails . each side rail may be coilable and resilient , or may be foldable and comprised of a plurality of hingedly connected fold sections . the first and second side rails preferably are formed from a single stringer having a first portion and a second portion , the stringer being made of a material to permit the stringer to bend for bringing the second portion in a confronting spaced relationship relative to the first portion to define the first and second side rails . the stringer may be made of a coilable resilient material or of a foldable material comprised of a plurality of hingedly connected fold sections . each of the rigid steps preferably comprises an l - shaped step piece having a tread portion and a riser portion , or each of the rigid steps may comprise a flat tread and the toy staircase may further comprise at least one brace portion connectable between the side rails . each of the rigid steps may comprise a tread portion hingedly attached to a riser portion , and there may be a plurality of the hingedly attached tread and riser portions hingedly attached to each other to form a continuous set of the rigid steps .