Field of Search:
52/182,188,190,191 182/90,194,228
Other References:
Klondike Band Campers by Standard Camping Trailer Co., P.O. Box 355, Parkville, Minnesota..
Description:
SUMMARY OF THE INVENTION
The stair units form a stairway of a compact construction that is without any end or back openings so as to eliminate any accidental slipping of a foot from the ends and rear side of a tread section. Adjacent stair units are secured together and to the stairway side members by bolt assemblies which, on being tightened, automatically align and lock together the stair units and the side members. The stairway is thus adapted to be easily assembled in a minimum of time by one man. Further, by virtue of their one-piece construction, the stair units may be nested together for shipping and storage purposes so as to appreciably reduce not only space requirements but also the number of parts to be handled.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a playground slide shown in assembly relation with a stairway that includes the stair units of this invention;
FIG. 2 is an enlarged fragmentary longitudinal sectional view of the stairway taken substantially along the line 2--2 of FIG. 1;
FIGS. 3 and 4 are enlarged sectional detail views taken on the lines 3--3 and 4--4, respectively, of FIG. 2;
FIG. 5 is a plan view of the one-piece stair unit of this invention; and
FIG. 6 is a foreshortened enlarged exploded perspective view of adjacent stair units illustrating the superposed relation of adjacent sides thereof in the stairway.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1 of the drawing, the stair unit 10 of this invention is shown embodied in a stairway 11 that forms part of a playground unit 12 illustrated as a slide. The stairway includes a pair of transversely spaced side members 13 for supporting the stair units 10.
As shown in FIGS. 5 and 6, each stair unit 10 is of a one-piece construction and includes a tread section 14, a riser section 16 and end sections 17. The tread section and riser section are relatively arranged to form an included angle of about ninety (90°) degrees and the end sections 17 are of a triangular shape extended between and connected to corresponding ends of the tread and riser sections. The top sides of the riser sections 16 and end sections 17 and the front side of the tread section 14 lie in a common plane normal to the end sections 17 so that the stair unit 10 is of a generally trough shape with closed ends. The rim of this trough shape body member has a marginal flange 18 located in such common plane and projected laterally outwardly from the upper sides of the riser and end sections, and from the front side of the tread section.
The marginal flange 18 is of a generally rectangular shape in top plan view (FIGS. 5 and 6) and has formed in each corner thereof a bolt receiving opening 19 of a square shape. The stairway side members 13 are of a channel shape in transverse cross section arranged with their open sides faced inwardly toward each other. The top leg or side 21 of each channel member 13 is formed with bolt receiving holes 22 (FIGS. 2 and 3) which are spaced longitudinally a distance apart corresponding to the spacing of the holes 19 transversely of a stair unit 10.
In the assembly of the stairway 11, and as best appears in FIG. 6, a pair of stair units 10 are arranged in a side by side relation with the upper end of a riser section 16 of a lower stair unit adjacent the forward end of a tread section 14 on a next upper stair unit. When thus arranged, the portion 23 of the flange 18 corresponding to or projecting from the tread section 14 is arranged in a superposed relation with the portion 24 of the flange 18 corresponding to the riser section 16 of a next lower stair unit 10. This superposed relation of the adjacent flange portions 23 and 24 is defined by the alignment of the corner holes 19.
The opposite pairs of sides of each hole 19 extend longitudinally and transversely of the stair units 10. As a result, when the holes 19 in the adjacent flange portions 23 and 24 are in full registration with each other adjacent stair units 10 are arranged in relative transverse and longitudinal alignment. This alignment is automatically obtained by bolts 26 (FIGS. 3 and 4), each of which include a dome-shaped head 27, a shank 28 and a locking member 29 adjacent the underside of the head section 27. The section 29 is of a square shape in transverse cross section and of a size to be snugly received within aligned holes 19 in adjacent flange portions 23 and 24. With the section 29 inserted within the aligned holes 19, to a position defined by the engagement of the underside of the head 27 with the top surface of the flange portion 23, the shank 28 is extended outwardly and downwardly from the hole 19 in the adjacent flange portion 24. Adjacent stair units 10 are thus locked against relative longitudinal and transverse movements by the coacting engagement of the locking member 29 with the side walls of the aligned holes 19 in the adjacent flange portions 23 and 24.
As previously mentioned, the bolt holes 22 in the upper sides or legs 21 of the channel members 13 are spaced a distance apart corresponding to the distance between holes 19 oppositely arranged transversely of a stair unit 10. With the bolt shanks 28 extended through the bolt holes 22, the stair units are rigidly attached to the side members 13 by nuts 31 engageable with the under side of the channel member legs 21.
With only the heads 27 of the bolts 26 exposed above the side members 13, the stairway 11 is free of any protruding obstructions. In this respect it is to be noted that the exposed shanks 28 and nuts 31 are substantially enclosed by the stair unit end sections 17 and web section 32 of the side channel members 13 (FIG. 4). Also, as clearly shown in FIG. 6, the tread section 14 is closed at the ends and rear side thereof by the end sections 17 and riser section 16, respectively, so as to completely eliminate any accidental slippage of a foot off of a tread section.
It is to be understood that a stair unit 10 is readily variable as to size and that the angular relation between the tread section 14 and riser section 16 may also be varied. A stair unit 10 may be of a cast construction or formed from a single piece of a sheet metal material.
Although the invention has been described with respect to a preferred embodiment thereof, it is to be understood that it is not to be so limited since changes and modifications can be made therein which are within the full intended scope of this invention as defined by the appended claims.