This invention relates to jogging apparatus and particularly to portable jogging apparatus.
Background and Summary of the Invention
It has heretofore been proposed that exercise or jogging apparatus be provided which permits the person exercising to run in place. Generally such apparatus has comprised a frame and a mat or other resilient surface mounted directly to the frame or mounted on the frame by elastic cords or tension springs, much in the manner of trampolines. It has also heretofore been suggested that a jogging surface can be provided by a solid elastomeric body. Both types of such apparatus are typified in U.S. Pat. Nos. 3,004,623, 3,892,403, 4,037,834, 3,634,895 and 3,641,601.
Among the objectives of the present invention are to provide an approved jogging apparatus which includes a tightly tensioned mat that has a larger usable area within the frame, more uniformly distributes the load to the frame, is lower in cost, can have controlled energy absorption by the proper selection of materials, is safer in that it does not utilize open spaces between the mat and the frame, has a sturdy, safe supporting structure and is foldable for shipment and storage.
In accordance with the invention, the jogging apparatus includes a frame having an elastomeric body bonded thereto and the mat bonded to the body such that the elastomeric body is under shear and holds the mat tightly stretched in biaxial tension. The jogging apparatus further includes legs that are pivoted to the frame and are normally extended outwardly and downwardly but can be folded inwardly within the confines of the frame. The legs are mounted by a construction which tends to urge the legs yieldingly outwardly when they are extended and tends to urge the legs yieldingly inwardly when they are folded inwardly.
Description of the Drawings
FIG. 1 is a plan view of the jogging apparatus embodying the invention.
FIG. 2 is a side elevational view of the same.
FIG. 3 is a fragmentary part sectional plan view on an enlarged scale of a portion of the jogging apparatus shown in FIG. 1.
FIG. 4 is a fragmentary sectional view taken along the line 4--4 in FIG. 3.
FIG. 5 is a cross sectional view of a portion of an elastomeric body used in the jogging apparatus prior to assembly.
FIG. 6 is a side elevational view of a leg of the jogging apparatus prior to assembly.
FIG. 7 is a partly diagrammatic view of the leg in extended and folded position.
FIG. 8 is a fragmentary sectional view similar to FIG. 4 showing the leg in folded position.
Description
Referring to FIGS. 1-4, the jogging apparatus 10 embodying the invention comprises a tubular frame 11 that preferably has a long or major axis and a short or minor axis. The frame 11 in its preferred form is generally rectangular and preferably comprises an ellipse having arcuate corners and curved sides blending in with the arcuate corners in the manner of a fifth order super ellipse.
As shown in FIG. 4, the tubular frame 11 is square in cross section and a elastomeric body 12 is bonded to the top surface and outside surface thereof. The elastomeric body 12 is hollow in cross section and preferably includes a top wall 13, a bottom wall 14 and inner and outer side walls 15, 16. The elastomeric body also includes a lip 17 that extends upwardly and inwardly from the area of juncture of the outer side wall 16 and top wall 13 and an upwardly extending annular bead 18 that extends upwardly from the bottom wall 14 between side walls 15, 16 (FIG. 5). The body 12 preferably extends around the entire top surface of the frame and preferably comprises one piece with its ends abutting to form a continuous annular body. Alternatively, body 12 may comprise a plurality of pieces in abutting or spaced relation to one another.
In its unloaded or undeformed state, the elastomeric body assumes the configuration shown in FIG. 5 so that the inner wall 15 and the outer wall 16 extend upwardly and outwardly and the lip 17 extends upwardly and inwardly. The body 12 further includes a vertical lip 12a extending downwardly from the area of juncture of the outer side wall 16 and bottom wall 14.
A mat 19 of flexible material is adhered to the top wall 13 of the elastomeric body and loads the elastomeric body in shear as shown in FIG. 4 such that the inner wall 15 and the outer wall 16 are generally vertical. As a result, the mat is stretched tightly.
The elastomeric body 12 is made of a resilient elastic material such as rubber or urethane having a high tear resistance and is preferably extruded. A satisfactory material has a durometer of 40-60 on the A scale. The mat 19 may comprise a polypropylene woven fabric. Suitable adhesives comprise urethane or other well-known adhesives.
In assembly of the jogging apparatus, the body 12 is bonded to the frame 11. More specifically, the bottom wall 14 is bonded to the top surface of frame 11 and the lip 12a is bonded to the outer surface of frame 11. The body 12 is then loaded or deformed radially inwardly, as by a band or clamp, bringing inner and outer side walls 15, 16 into vertical position. The periphery of mat 19 is then inserted between top wall 13 and lip 17, the lip is forced downwardly on the mat and the mat is bonded to the body 12. After the bonding, the load on the body 12 is released and the mat is thereby stretched in biaxial tension due to the tendency of the body 12 to return to its original configuration. The body 12 thus is placed under shear.
In accordance with the invention, the structure provides a large exercise area in a simple low cost manner without having space between the jogging surface and the frame thereby making the jogging apparatus safer.
Referring to FIGS. 3-5, legs 21 are provided at circumferentially spaced points on the frame, preferably at the arcuate corners, and are supported on the frame by brackets 22 which are generally U-shaped. A layer 21a of elastomeric material is positioned between each bracket and the bottom and inner and outer side walls of the frame 11 and is bonded thereto as by adhesive.
Each bracket 22 includes radially inwardly extending ears 23a, 23b. Each leg 21 is preferably made of a spring tempered metal rod that is bent in a U shape defining legs 24a, 24b which in the extended position have vertical portions 25a, 25b, horizontal portions 26a, 26b engaging the undersurface of the bracket 22 on the frame, and a downwardly and outwardly inclined portion 27a, 27b joined to a ground engaging portion 28. The legs 24a, 24b further include outwardly extending horizontal portions 29a, 29b that are pivoted to ears 23a, 23b.
As shown in FIG. 3, the axes of the openings in ears 23a, 23b through which the portions 29a, 29b extend lie in the same plane parallel to the plane of mat 19. In addition, the axis of the opening in bracket 23b is displaced radially inwardly of the axis of the opening in bracket 23a (FIGS. 3, 4). Portion 26a is shorter than portion 26b and portion 27a is longer than portion 27b so that in the untensioned state the portion 29b is displaced laterally or radially inwardly and is lower or not in the same horizontal plane as viewed in elevation (FIG. 6). As a result, when each leg is mounted in its respective bracket, it is placed under tension due to the stressing of the leg to bring portions 29a, 29b into the same plane. More specifically, a force couple is produced. When the leg is extended, this stress tends to urge the leg outwardly or counterclockwise as viewed in FIGS. 4 and 7 bringing portions 26a, 26b into engagement with the underside of bracket 22. However, when the leg is folded inwardly, it moves across an axis between the portions 29a, 29b so that the stress tends to urge the leg inwardly or clockwise as viewed in FIGS. 4 and 7 bringing it into the broken line position shown in FIG. 7 or the solid line position shown in FIG. 8 yieldingly urging portion 28 against the underside of mat 19.
In this fashion, the frame is supported at points beyond the periphery of the frame 11 providing a stable jogging surface.
In order to facilitate shipment or storage by making the package small, the legs 21 can be folded inwardly within the plane of the jogging apparatus as shown in FIG. 8.
In use, the legs 21 are extended and the jogging apparatus is placed on a floor. The resilience of the spring legs and the layer 21a permit sufficient resiliency to accommodate lack of flatness in the floor. As a result, the jogging apparatus will not rock or be unstable even before user steps on mat 19.