Description:
BACKGROUND OF THE INVENTION
The present invention relates to playground and recreational equipment in general and, more particularly, to an improved swing seat for suspension from an overhead support.
Various types of swing seats are well known in the art including those employing some form of reinforcement, such as the swing seat described in U.S. Pat. No. 1,975,262, issued Oct. 2, 1934. Recently, attention in the swing seat art has been directed toward various plastic swing seat constructions such as those shown in U.S. Pat. Nos. 3,260,522 and 3,261,607. An example of a current plastic swing seat is the seat manufactured by the Irwin Corporation of 85 Factory Street, Nashua, New Hampshire 03060 and sold under the model nos. 3702,3712, and 3726.
These swing seats are generally rigid and in the case of the seat described in U.S. Pat. No. 3,261,607, a beam construction is used for longitudinal rigidity while lateral rigidity is obtained by means of cross-bracing.
It is a general object of the invention to provide an improved swing seat which employs a deformable arch construction to transmit vertical loads to a swing seat suspension element.
It is a specific object of the present invention to provide an improved swing seat which can be fabricated from readily available plastic materials utilizing conventional molding techniques.
It is still another object of the invention to provide an improved swing seat which is relatively stable and less tippable.
These and other objects and features of the present invention will best be understood from a detailed description of a preferred embodiment thereof, selected for purposes of illustration, and shown in the accompanying drawings in which:
FIG. 1 is a side elevation of the improved swing seat of the present invention;
FIG. 2 is a plan view of the swing seat illustrated in FIG. 1;
FIG. 3 is a bottom view of the swing seat shown in FIGS. 1 and 2;
FIG. 4 is an end view of the swing seat shown in FIGS. 1,2, and 3;
FIG. 5 is a view in cross-section taken along line 5--5 in FIG. 2;
FIG. 6 is a view in cross-section taken along line 6--6 in FIG. 2;
FIG. 7 is a view in cross-section of a portion of one end of the swing seat showing the position of a chain link swing seat suspension element;
FIG. 8 is a view in cross-section showing an alternative embodiment of the invention; and,
FIG. 9 is a view in cross-section taken along line 9--9 in FIG. 8.
Turning now to the drawings and particularly to FIGS. 1 through 4 thereof, there is shown an improved swing seat constructed in accordance with the present invention and indicated generally by the reference numeral 10. The swing seat 10 comprises a continuous walled shell 12 having an upper wall section 14 and a lower wall section 16. The upper and lower section are formed preferably from a polyethylene of either low or high density to provide a semi-rigid construction. The plastic swing seat 10 can be manufactured by a variety of techniques including injection molding, blow molding, and rotational molding. Currently available twin sheet or twin shell forming methods can also be employed.
It will be appreciated from an inspection of the drawings that the improved swing seat 10 is a unitary structure in its finished form. The swing seat 10 can be molded as a single unit or in separate sections which are subsequently fastened together to form the unitary shell structure. For example, the upper wall section 14 and the lower wall section 16 can be fabricated individually and then assembled by heat sealing, adhesive means, mechanically interlocking elements, etc., to form the finished unitary swing seat shell. The term "continuous walled" as used herein is intended to cover the characteristic of the finished shell and includes constructions in which the shell is formed as a single unit or as separate units which are subsequently fastened together by any one or a combination of the methods previously mentioned.
Looking at FIGS. 1 and 2, and the sectional views shown in FIGS. 5, 6, and 7, it can be seen that the upper wall section has a seating surface portion 18. Preferably, the seating surface portion 18 has a plurality of longitudinally extending ribs 20 which provide foot or seating grips. A plurality of drain and cooling apertures 22 are also provided in the upper wall section of the preferred embodiment of the present invention. The upper wall section apertures 22 are fluidly connected to corresponding apertures 24 in the lower wall section by a corresponding plurality of hollow vertical webs 26 each of which defines a fluid passageway 28 as shown in the sectional views depicted in FIGS. 5 through 9.
In order to provide a relatively flexible, yet stable, swing seat, the arch principle is used in the improved swing seat 10 to transmit vertical loads to a swing seat suspension element shown in generalized form in FIG. 1 and identified by the reference numeral 30. Referring to FIGS. 3,5,6,8 and 9, the lower wall section 16 defines at least one longitudinally extending arch member 32 which is positioned between the end portions 34 of the lower wall section. Preferably, the improved swing seat 10 has a plurality of longitudinally aligned, longitudinally extending arch members 32a and 32b as shown in FIGS. 3 and 5. Collectively, the two arch members 32a and 32b comprises one set of arch members. Laterally spaced from the first set of arch members, as shown in FIG. 3, are two other sets of arch members 32c-32d and 32e-32f. Lateral bracing is provided by lateral webs 33. It will be noted by examining FIGS. 3,5,6, and 9 that in both embodiments of the present invention, it is desirable to have a plurality of longitudinally extending arch members 32 which are laterally spaced from each other.
Looking now at FIGS. 5,6,8, and 9, it can be seen that the previously mentioned vertical webs 26 structurally tie together the seating surface portion 18 of the upper wall section and the arch members 32 of the lower wall section. Since the upper and lower wall sections are formed from a relatively flexible plastic material, any vertical loads imposed upon the seating surface portion 18 will tend to flatten the arch members 32. The vertical loads are transmitted by the arch members 32 to the suspension element 30 by means of the inner wall surfaces 36 of the suspension element receiving apertures 38 located in each end portion of the swing seat 10. Preferably, at least a portion of the inner wall surface 36 is shaped to conform to the shape of the suspension element 30. This can best be seen in the cross-sectional view shown in FIG. 8 which depicts the use of a flexible link chain 30 as the suspension element. A portion 36a of the inner wall surface 36 is indented to provide a cavity for a portion of one link of the chain suspension element 30.
Referring back to FIGS. 1,2, and 4 through 9, it can be seen that the end portions 40 of the swing seat extend upwardly beyond the plane of the seating surface portion 18. This structural configuration is desirable in order to increase the stability of the swing seat against rotation about its horizontal axis. Such an arrangement prevents the tippiness normally encountered with relatively flat swing seats. It is also desirable to have at least a portion 40a of the end portions curve upwardly from the seating surface 18 to provide a foot grip for the user in the standing position.