Locking mechanism for folding legs

#1. Field of the Invention

#This invention relates to foldable support legs for tables, chairs, portable staging, risers, or other similar portable equipment requiring foldable legs for supporting a surface. More particularly, the present invention relates to an improved locking mechanism for folding legs which is simpler and stronger than other similar mechanisms.

#2. Related Art

#FIG. 1A is an underside pictorial view of a table provided with a leg locking mechanism according to the present invention, showing two different configurations for connecting the table legs, and wherein the selectively releasable engagement mechanism for the dual leg configuration includes a buckling rod deflecting mechanism.

#FIG. 1B is an underside view of the table of FIG. 1 wherein the selectively releasable engagement mechanism for the dual leg configuration includes a tension member deflecting mechanism.

#FIG. 2 is a pictorial view of a rotary coupler and base according to the present invention, showing the angularly spaced, radial teeth of the coupler.

#For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the exemplary embodiments illustrated in the drawings, and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended. Any alterations and further modifications of the inventive features illustrated herein, and any additional applications of the principles of the invention as illustrated herein, which would occur to one skilled in the relevant art and having possession of this disclosure, are to be considered within the scope of the invention.

#Viewing FIG. 1A, the invention is shown in use with a table 10, which is shown inverted for clarity. It will be apparent that the present invention is suitable for use with a wide variety of items other than tables, such as chairs, portable stage platforms, risers, and any other support surface requiring foldable support legs. The table 10 typically has a leg assembly 12 comprising two legs 14a and 14b rigidly connected by a crossbar 16. The top end of each leg 14a and 14b includes a coupler 18, which is joined to a base 20, which in turn is affixed to an angle bracket 22, which is securely affixed to the underside 24 of the table 10. Alternatively, the base may be affixed to a table runner (see, e.g., 174 in FIG. 6), which may be integral with the table top, or may comprise a separate element attached to the table. The couplers 18 and bases 20 together form a rotary coupler which is configured to lock together only at desired angular orientations, preferably including an extended position wherein the legs extend generally perpendicularly from the underside of the table, as shown, and a folded position wherein the legs are parallel to the underside 24 of the table 10 (shown in dashed lines in FIG. 1A). It will be apparent that the base 20 and angle bracket 22 may be configured as a single unit, thus allowing the rotary coupler to be directly affixed to the underside of the table.

#Referring to FIGS. 2 and 3, the coupler 18 comprises a circular face 26 which is oriented generally perpendicularly to the long axis of the leg 14, and includes a plurality of radial teeth 28 comprising a series of ridges and valleys. The teeth 28 have flattened top surfaces, are preferably non-uniform in width, and are designed to mate with a set of radial teeth 30, comprising a series of ridges and valleys having an oppositely corresponding mating configuration to the teeth 28, which are formed on a circular face 32 of the base 20. The coupler 18 and base 20 are preferably formed of glass-filled injection molded plastic. This material is inexpensive, and lends itself well to large scale production. It also has a high strength-to-weight ratio and allows close control of tolerances during manufacture.