US2763455A - Frame construction for playgyms - Google Patents

Description

1956 D. scARAMuccn FRAME CONSTRUCTION FOR PLAYGYMS 2 Sheets-Sheet 1 Filed Dec. 16, 1952 INVENTOR.

ATTORNEYS p 1956 D. SCARAMUCCI 2,763,455

FRAME CONSTRUCTION FOR PLAYGYMS Filed Dec. 1e, 1952 2 Sheets-Sheet 2 United States Patent FRAME CONSTRUCTION FOR PLAYGYMS Domer Scaramucci, Oklahoma City, Okla.

Application December 16, 1952,'S erial No. 326,229

Claims. (Cl.287--54) This invention relates generally to swings, playgyms, gliders, etc. which include spaced pairs of supporting legs connected by a top bar and more particularly to a coupling for connecting the top bar and its supporting legs.

Couplings of this type are known in the art and due to the severe stresses to which they are subjected during use of the swings and similar equipment, have proven to be unsatisfactory because of early failure due to lack of strength, lack of rigidity of the frame, poor design, and

excessive costs due to the necessity for using castings, heavier and more complex members and .difiicult'y of manufacture of the same.

The legs and frame members of swing structures are usually tubular and in oneprior art construction, the ends of the tubular bar and legs are flattened, .aper-tured, and joined by bolts. Another construction involves the bolting of arcuate plates to the ends of the top bar and flattening and conforming the upper ends of the legs thereto and welding. In either case, the movement of a swing and particularly one of the parallel bar type, results in a strong torque tending to oscillate the top bar which flexes the flattened portions, and loosening and breakage soon results even though, in the latter case, heavier tube members must necessarily be used.

The use of short lengths of heavy tubing as sockets-for the ends of the legs and top bar is also known in various forms and differ mainly .in their fabrication, cast socket designs being excessively costly and rarely employed. Such heavy tube sockets are cut at one end to conform with the top bar, andset screws .are set in the leg sockets to retain the legs in operative position. While this more expensive construction partially eliminates the twisting and loosening at the top bar, another serious problem is created in that the twisting stresses are concentrated at the set screws. These stresses are increased by the anchoring of the legs to the ground to prevent tipping and the set screws gouge through the tubular legs and Work loose so that positive locking cannot be achieved.

Accordingly, the chief object of the present invention is to provide an improved coupling for the top bar and legs of swing and playgym structures which will obviate the disadvantages characterizing known prior art structures.

Another important object of the present invention is to provide an improved coupling which will continuously withstand the severe torsional forces acting on the top bar and legs through use of the swings without loosening or failure thereof.

A further important object is to provide an improved coupling of the type described which will act as a positive leg fastening means and also brace and steady the frame even when used with lighter tubes.

A still further important object is to provide an improved coupling for top bars and their supporting legs in which the twisting stresses transmitted from the bar will be distributed throughout the portion of the tube held by the coupling.

Another object is to provide an improved coupling of 'ice the type described which may be readily and economically manufactured vand of long life in use.

"the invention. In these showings;

Fig. 1 is a perspective view of a swing set or playgym employing the coupling comprising the present invention;

Fig. 2.15 a plan view :to an enlarged scale of the blank fromwhich the coupling is formed;

Fig. 3 is a fragmentary side elevational view showing .theformed coupling fixed in operative position on the end of the top bar;

Fig. 4 is an end :.elevationalview thereof;

Fig. 5 is a bottom view thereof;

Fig. 6 is a fragmentary perspective view thereof;

Fig. 7 is a side elevational view of a modified form .of the invention;

Fig. 8 is an end elevational view thereof;

Fig. 9 is an end elevational view of a further modification of the invention; and

Fig. 1.0 is a side elevational view of a still further modification of the invention.

Referring to Fig. 1 of the drawings, numeral 12 designates a swing set or playgym as a whole which includesa pair of .chain supported swings 14 and a parallel .b ar swing 16, all supported by .a .top tube or bar 18 connected with spaced pairs of diverging legs 20 by means of the couplings also indicated as a whole as 22. The

pairs of legs are braced intermediate their lengths by connecting bars 24. The top bar and legs are usually and preferably formed of strong steel tubing.

aligned when a .bolt 28 is slipped therethrough. A pair of diyerging leg tube receiving sockets are thus formed -.(.Fi gs. 3:6 incl.) connected by overlying spaced, intervening webs and the angle of divergenceis supplementary to the angle formed between the lines from the wing apertures to the central aperture before bending.

It will be noted that the notch 25 forms a supporting shoulder for one end of the top bar 18 which is closed by the overlapped wings 26 and the two members are welded together along their entire line of contact including the shoulder 25 and the wings 26. A second coupling 22 is similarly fixed to the other end of the tube 18.

In assembling the legs to the top bar and coupling unit thus formed, which may be done at the site of intended use of the swing, etc., the upper ends of each pair of legs are inserted in the diverging sockets formed in the couplings 22. The brace bars 24 are next fixed to the legs in order that the frame may be prestressed when the couplings are then tightened.

The tightening of the single bolt 28 of each coupling 22 draws the webs toward each other and tends to wrap the socket about each leg so that upon final tightening, the socket is held in tension about the leg which is in a state of compression. Thus, the stresses are evenly distributed throughout the leg tube and are not concentrated at any single point.

The coupling provides a prestressing of the frame which insures its continued rigidity as well as a positive leg gripping with distributed stresses. As seen in Fig. 6, the tightening of the bolt 28 sets up forces generally indicated as x which tend to close the vertex angle y formed by the legs. The forces x are adequately resisted by the brace bars 24 which is thus prestressed in compression by the tightening of the bolt and any slack is permanently eliminated. Y

The Figs. 7 and 8 disclose a slightly modified form of the invention in which the coupling 30 is stamped from a blank so shaped as not to close the end of the tube 18 but to provide a pair of notches to conform with the bottom thereof. The coupling 30 and the tube 18 are joined by welding as before and inwardly of the end of the tube; and the end may or may not be closed as desired.

Fig. 9 discloses a form of the invention which embodies the principles described but which permits, by the use of a pair of bolts 28, the accomplishment of the wrap around principle of the coupling 32 separately with respect to each leg.

The disclosure of Fig. 10 is almost identical with that of Figs. 16 incl. but differs in that the wings 26 terminate and overlap on the inside of the coupling 34 rather than on the outside as disclosed in the coupling 22.

It will now be readily apparent that the improved coupling comprising the present invention provides a continued, positive clamping of the tubular legs with an even distribution of the stresses thereto; eliminates the need of making and installing an end cap for the top bar; permits the use of lighter tube members as the sockets grip the legs evenly so as to minimize crushing, distortion or failure and through prestressing increase the rigidity of the coupling; and promotes economy in fabrication through the use of stamped plate instead of castings or specially cut heavy tubes.

It is to be understood that the forms of the invention herewith shown and described are to be taken as preferred examples of the same and that various changes in the shape, size and arrangement of parts may be resorted to without departing from the spirit of the invention or the scope of the subjoined claims.

I claim:

1. A coupling for the ends of the horizontal top tube and divergent legs of swing frames, etc. comprising a single, one-piece, elongated sheet metal body notched at the center of one long side and configured to provide edges to closely receive and conform to a portion of the walls of the top tube along an irregular line substantially angled to the axis of the tube and adapted to be welded thereto along the engaging edges, said body sheet beyond said notch defining a pair of merging but divergent leg receiving sockets directed to hold the ends of the legs against said top tube opposite the edge connections thereto, and intervening webs edge connected to the sockets and overlying and spaced apart, and means to draw said webs toward each other to tension both sockets about the leg ends.

2. The coupling of claim 1 in which said webs are integral extensions of the sheet material of the sockets and a single bolt is positioned to draw them toward each other to increase the tension about the leg ends and simultaneously apply decreasing angle of divergence tension to the sockets. I

3. The coupling of claim 2 in which one of said webs comprises overlapping portions of said sheet metal body each perforated for said bolt whereby leg gripping tension is applied separately to each socket.

4. For use in a frame for swings, etc. having a top tube, a pair of supporting divergent tubular legs and a connecting brace bar between the latter, the combination of a one-piece sheet metal coupling permanently fixed to the top tube adjacent to and covering one end thereof, said coupling having a shape to form a pair of divergent leg tube receiving sockets each substantially open where it faces the other, one edge of each opening being connected' by a continuous web and each other edge having a web extending therefrom and overlapping that from the other, said continuous and overlapping webs being spaced apart and means to draw them toward each other to clamp the leg tubes and to simultaneously tend to reduce the angle of socket divergence whereby the brace bar is placed under compression.

5. The device of claim 4 in which said coupling sheet is notched to receive and closely support the end portion of the top tube and means welding the edges of the notch to the walls of the top tube to integrate these parts.

References Cited in the file of this patent UNITED STATES PATENTS 600,276 Crosby et a1. Mar. 8, 1898 1,223,717 Mintz Apr. 24, 1917 1,380,468 Drew June 7, 1921 1,470,627 Lamplugh Oct. 16, 1923 1,949,197 Cornell Feb. 27, 1934 2,603,272 Rowand July 15, 1952 FOREIGN PATENTS 7 671,520 France Dec. 13, 1929 860,901 France n v t v Jan. 28, 1941

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