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BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention pertains to supporting devices such as those used to support roadway signs and barriers to advise nearby motorists and bystanders of construction sites and other hazards. The present invention also pertains to quick release mechanisms for deploying the supporting device. 
     2. Description of the Related Art 
     There has been increasing demand for warning and advisory information concerning worksite activities. For example, organizations charged with safety concerns have come to increasingly appreciate the effectiveness of lightweight temporary sign stands to warn oncoming motorists of nearby work activities. Typically such lightweight sign stands are made to be collapsible for compact storage. In order to complement the sign stand, the sign panels are made of lightweight foldable material. Such completed sign stand assemblies may be conveniently stored in work vehicles, available for ready deployment, thereby bypassing the need to withdraw the sign stand assemblies at a remote location and to schedule their delivery to the worksite. Such sign stand assemblies have offered a great advantage for work operations which last only a day, or part of a day. Work situations of this type present unique demands not associated with long term projects, since motorists will not encounter the worksite on a repeated basis and thus will not have the benefit of past experience as a forewarning. It is important that the sign stand assemblies offer reliable advisory and instructional assistance, particularly for motorists traveling at highway speeds. Sign stand assembles located adjacent a highway must withstand wind gusts generated by moving vehicles as well as wind gusts occurring at outdoor locations, which are usually unabated, especially for multiple lane highway constructions. 
     Substantial advances have been made in the art of lightweight collapsible sign stand assemblies. For example, commonly assigned U.S. Pat. No. 4,954,008 has been met with ready commercial acceptance and has been recognized not only for its provision of a strong reliable sign stand support, but has also been found to offer substantial labor savings when the sign stand is deployed, and again when the sign stand is collapsed for storage, after use. U.S. Pat. No. 4,954,008 provides a quick release mechanism located at the point where support legs are pivotally secured to a base for supporting the sign mast. The quick release mechanism is operated by depressing a lever arm in order to allow free rotating of the support leg with respect to the remainder of the sign stand assembly. 
     Frequently, sign stand assemblies must be erected or taken down in inclement weather. At times, the combination of wind gusts occurring during inclement weather and a sudden pressure burst from nearby traffic can substantially complicate a worker&#39;s task. 
     SUMMARY OF THE INVENTION 
     In researching ways in which sign stand assemblies can be improved, it has been discovered that different workers find manipulation of one type of quick release mechanism to be easier in a particular situation than other types of quick release mechanisms. 
     Improvements in sign stand assemblies are continually being sought. It is an object of the present invention to provide quick release mechanisms having different types of actuating motions associated with the deployment or storage of support legs pivotally mounted to a support base. 
     Another object of the present intention is to provide sign stand assemblies having improved stronger joinder of support legs to a support base. 
     A further object of the present invention is to provide support bases and quick release mechanisms therefor constructed from a minimum number of inexpensive components. 
     These and other objects of the present invention are provided in a foldable supporting device comprising: 
     a base member including a plurality of support flanges having respective outer peripheries; 
     a plurality of legs pivotally mounted to respective support flanges for pivotal movement between operational and storage positions; 
     said legs defining a slot for receiving portions of a respective support flange outer periphery as the leg is pivoted between unfolded and folded positions; 
     the outer peripheries of the support flanges defining at least one locking recess; 
     a plurality of locking pins extending through respective legs, the locking pins having an elongated double-ended body with an enlarged head at one end lying outside the leg and an exposed portion at the other end extending beyond the leg; 
     the locking pins carried by the legs so as to be positioned adjacent.the support flange outer periphery and so as to be movable between a locked position received in the locking recess and an unlocked position outside of the locking recess; 
     a plurality of spring bias means carried on respective legs so as to urge the locking pin body into the recess to lock the leg against pivoting about the support flange; and 
     the locking pin movable out of the recess when the exposed portion is deflected so as to oppose the force of the spring bias means. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a spring bias member according to the principles of the present intention; 
     FIG. 2 is a fragmentary perspective view of a sign stand support base; 
     FIG. 3 is a side elevational view thereof; 
     FIG. 4 top plan view thereof; 
     FIG. 5 is a side elevational view of the spring bias member; 
     FIG. 6 shows a portion of FIG. 4 on an enlarged scale; 
     FIG. 7 is a view similar to that of FIG. 6 showing actuation of the locking pin thereof; 
     FIG. 8 is a fragmentary view showing a self centering locking pin arrangement; 
     FIG. 9 is a view similar to that of FIG. 8 but showing a different s centering arrangement for the locking pin; 
     FIG. 10 is a perspective view of a sign stand according to the pent invention; 
     FIG. 11 is a fragmentary perspective view of an alternative spring bias arrangement. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to the drawings, and initially to FIGS. 1-4, a foldable supporting device is generally indicated at  10 . The foldable supporting device includes a support base  12  and a plurality of support legs  14 . In the preferred embodiment, four support legs are employed, as shown in FIG.  4 . Two of these support legs have been omitted from FIG. 2 for clarity of illustration. 
     In the preferred embodiment, support base  12  is provided as a weldment including side plates  14  and a floor member  16 . Side plates  14  are preferably formed as a monolithic stamping of sheet metal material. Side plates  14  are stamped to form a pair of support flanges  20  extending from an intermediate upright wall  22 . The upright wall  22  is joined to floor  16  by a metallurgical joinder  24  by welding, brazing or the like conventional joining technique. In the preferred embodiment shown in FIG. 10, the support base  12  is covered by a hood member so as to enclose one or more springs for biasing an upright sign mast extending above the support base. Another example of the hood and sign mast arrangement is shown in commonly assigned U.S. Pat. No. 4,954,008, the disclosure of which is hereby incorporated by reference as if fully set forth herein. 
     As will be seen, for example in FIG. 2, legs  14  are of preferably rectangular, most preferably square tubing which are bifurcated or split at one end by an elongated notch  28 . If desired, legs of cylindrical or other shape can be used. The notch  28  is dimensioned to receive the support flanges  20  of support base  12 . Preferably, the support flanges  20  are of generally planar configuration, although other configurations may be employed for the support flanges  20 . As can be seen in the right hand portion of FIG. 2, the support flanges  20  are provided with an aperture  30  and recesses  32 , 34  spaced about an outer periphery  46  of the support flange. Pivot shafts in the form of bolt fasteners  40  pass through apertures  30  as well as complementary apertures formed in the legs  14 , so as to pivotally join the legs to corresponding support flanges  20 . The notches  28  are dimensioned so as to clear the outer periphery of the support flange allowing the legs to swing between opened and storage positions illustrated in solid lines and phantom lines, respectively, in the left hand portion of FIG.  3 . The leg  14  shown in the foreground portion of FIG. 2 is fixed in the open or deployed position extending at a relatively small acute angle to a support surface. The leg  14  shown in the background portion of FIG. 2 is locked in a closed or storage position, generally upright, at a normal angle to a support surface. 
     In the preferred embodiment, the peripheral portion  35  of flange  20  is made part circular and the notch  28  formed in leg  14  for receiving the flange is closely spaced with respect to the support flange outer periphery, as indicated in the background portion of FIG.  2 . The notch  28  in the foreground portion of FIG. 2 is shown exaggerated in length for illustration purposes. With a close sliding fit of the flange  20  within leg  14 , the leg receives continuous wobble-free support from the flange at all points of its operation between open and closed positions. If desired, the notch  28  can be made considerably larger than that needed to receive flange  20  and an optional sleeve or insert can be fitted within notch  28 , although this has not been found necessary in the preferred embodiment, as illustrated. 
     Referring to FIG. 4, a portion of a sign panel  46  supported by mechanism  10  is shown in phantom. The areas designated by the numeral  50 , herein the “inside portions” between sign legs  14  is located facing the planar faces of sign panel  46 . Spring strips  52 , one for each leg  14 , are located in these inside areas. The “outside portions” between support legs  14  are designated by the reference numeral  54  and generally are located facing an edge of sign panel  46 . 
     As shown in FIGS. 2 and 3, for example, the legs  14  are movable between an open or unfolded position shown at the bottom of FIG. 2 and a folded or storage position shown in the upper corner of FIG.  2 . FIG. 3 shows, in its right hand portion, a leg  14  intermediate the deployed and storage positions which correspond to notches  32 ,  34 , respectively. Turning now to FIGS.  1  and  5 - 7 , a locking or detent mechanism for releasably securing the legs in either of the storage or deployment positions will now be described. As shown, a locking pin  60  is provided for each leg. As can best be seen in FIGS. 5-7, the locking pin  60  has a generally cylindrical body  62  and an enlarged head  64 . 
     With reference to FIG. 2, it can be seen that legs  14  are of generally hollow tubular construction with opposed side walls  14   a  facing the “interior” of the support device and  14   b  facing outside of the support device so as to be visible when standing to one side of the support device, in the manner depicted in FIGS. 3 and 10. With reference to FIGS. 6 and 7, a hole  70  is formed in sidewall  14   a  of leg  14  and is closely dimensioned with respect to the cross-section of the body  62  of pin  60 . As can be seen in FIG. 6, the pin body  62  extends through a slot  72  formed in leg sidewall  14   b.  Preferably, pin body  62  is dimensioned so as to extend a substantial amount beyond leg wall  14   b  with an exposed free end suitable for grasping to operate the locking arrangement of the support device. 
     As can be seen in FIG. 2, for example, locking pin  60  extends through a slot  72  formed in the outboard wall  14   b  of leg  14 . As can be seen for example in FIG. 7, while the end of locking pin  60  adjacent head  64  is free only to pivot or rock, the free end  62  of locking pin  60  is free to swing an arc, being limited by the dimension of slot  72 . As illustrated in FIG. 7, free end  62  of locking pin  60  is swung to its furthest, unlocked position. With additional reference to FIG. 2, the legs  14  are freed to pivot about their respective support flanges  20  with the support flanges passing through slot  28  formed in the legs  14 . As previously mentioned, recesses or detents  332 ,  34  are formed in each support flange  20 . FIG. 6 shown locking pin  60  engaged in a lower recess  32  of support flange  20 , thus preventing rotation of the leg about threaded fastener  40 . The location of hole  70  and the lengthwise dimension of slot  72  are chosen such that, with locking pin  60  swung to its furthest unlocked position shown in FIG. 7, interior portions of the locking pin body clear the support flange thereby allowing leg  14  to pivot about threaded fastener  40 . 
     With reference to FIG. 7, unlocking of pin  60  from support flange  20  allows leg  14  to be swung in an upward direction. If desired, the locking pin can be released by the operator once the leg is unlocked, thereby allowing the locking pin to travel across the outer surface  36  of the support flange as the leg is swung to its upright storage position. On attaining the desired upright position, locking pin  60  falls into the recess  34  under bias force of spring  52 , thereby securely locking the leg in a storage position. In the storage position (as shown in the upper left hand portion of FIG.  2  and in phantom in the left hand portion of FIG.  3 ), an upward deflection of the free end  62  of locking pin  60  will release the leg to fall toward its open position under the force of gravity. With sufficient travel of leg  14 , the locking pin  60  carried with the leg will be urged into the lower recess  32  under force of spring strip  52 . 
     With reference to FIGS. 5-7, it will be observed that spring  52  operates only on the enlarged head  64  of the locking pin. This arrangement provides substantial manufacturing advantages since springs internal to hollow legs  14  can be eliminated. Some operators of support devices prefer to visually observe operation of spring bias members and an advantage is obtained with the present invention, in the regard, as can be seen by comparing the position of spring  52  in FIGS. 6 and 7. 
     A further important advantage is obtained with the present invention in that the enlarged head  64  of the locking pin is substantially enclosed by the flat, smooth faced outer surfaces of spring strip  52 . As can be seen for example in FIG. 2, the spring strips  52  are located in the “inside” surfaces of the legs  14 , areas which are typically maintained clear of unwanted obstructions which may interfere with operation of the spring strips. 
     If further “shielding” of enlarged head  64  is desired, the arrangement shown in FIG. 11 can be employed where sidewalls  98  are added to spring strip  52 . As will be appreciated, the bias means shown in FIG. 11 can be readily formed using conventional metal stamping techniques. The sidewalls  98  are received in slots  102  formed in leg wall  14   a.  If desired, the slots  102 ,  92  can be merged to form a single continuous U-shaped slot and sidewalls  98  can extend to stop limit  82 . In general, this extra degree of shielding has been found unnecessary. 
     With reference to FIG. 1, additional protection for the spring strip  52  can be provided with an optional hook or L-shaped stop limit  82 , preferably formed as part of the stamping of bias member  52 . A first part  84  of stop limit  82  travels within a slot  92  formed in leg wall  14   a.  The slot guides the position of leg  84  as spring strip  52  is expanded. 
     A second part  86  of stop limit  82 , in extreme excursions of the locking pin will contact the leg wall  14   a  in the manner indicated in FIG. 7, thus effectively preventing disengagement of the free end of spring strip  52  from leg  14 . 
     The optional stop limit  82  of spring strip  52  also operates to prevent unwanted rotation of the spring strip and thereby further ensures that the enlarged head  64  of the lock pin will remain covered. If desired, other anti-rotation arrangements can be provided. For example, with reference to FIG. 5, an optional hole  94  can be formed in leg  14  to receive a projection (not shown) extending from the secured or closed end of the spring strip. For example, a finger-like portion (not shown) can extend from spring strip  52  adjacent threaded fastener  40 , with the free end of the finger being inserted in hole  94 . 
     As a further alternative, the round hole  94  shown in FIG. 1 can be replaced with a hole having an elongated, square or other non-round edge. For example, a pair of opposed elongated slots can extend outwardly from round hole  94  to receive a pair of complementary-shaped locking ears extending from the enlarged head of threaded fastener  40 . 
     As an optional provision, enlarged head  64  of locking pin  60  can be provided with a pair of anti-rotation ears  112  received in slots  114  formed in sidewall  14   a  of arm  14 . As shown in FIGS. 8 and 9, ears  112  are arranged in diametrically opposed positions and are configured to promote rocking or pivoting of the locking pin, with the exposed portion of the locking pin constrained to travel within a plane. The anti-rotation ears may operate alone to limit travel of the free end of the locking pin within a plane, or they may cooperate with elongated slots  72  in this regard. 
     Referring now to FIG. 10, a sign assembly  200  includes a flexible sign panel  202  mounted on an upright support  24  which spans the upper and lower corners of the sign panel. The remaining horizontal corners of the sign panel are supported by a cross member (not visible) attached to upright  204 . Upright  204  is releasably joined to a base fitting  206  which includes a hood  208  partially enclosing a coil spring  210 . The spring  210  and hood  208  are mounted between upright walls  22  of foldable supporting device  10 . In FIG. 10, the operator  220  is located on the “outside” portions of legs  14  with the operator&#39;s foot  222  located immediately adjacent the protruding portions  62  of locking pin  60 . Thus, it is possible for the operator to engage exposed portion  62  with a shoe tip. 
     An advantage is offered by the present invention in restricting travel of the locking pin to a single direction. With reference to FIG. 6, it will be observed that locking pin  60  is, in its locked position, biased against one end  72   a  of slot  72 . Thus, an operator who is not intimately familiar with the supporting device can safely nudge the exposed portion of the locking pin to determine the direction of travel permitted to it. If, with reference to FIG. 6, the operator should attempt to move the exposed portion  62  of the locking pin to the right, the locking pin will be supported by end  72   a  of slot  72  which will prevent unintended damage. The operator will then be prompted to move the locking pin in the opposite direction, as shown in FIG. 7, which, with sufficient travel of the locking pin free end, will free the leg for travel to the folded position. If desired, the length of slot  72  can be chosen such that, with reference to FIG. 7, the locking pin will be constrained from slot  72  from over travel, and this alone may be sufficient to prevent over-bending of flat spring  52 . As mentioned, the flat spring can also be provided with the hook-shaped stop limit, described above. 
     The drawings and the foregoing descriptions are not intended to represent the only forms of the invention in regard to the details of its construction and manner of operation. Changes in form and in the proportion of parts, as well as the substitution of equivalents, are contemplated as circumstances may suggest or render expedient; and although specific terms have been employed, they are intended in a generic and descriptive sense only and not for the purposes of limitation, the scope of the invention being delineated by the following claims.

Summary:
A quick release mechanism for a sign stand base having support legs pivotally joined to a support flange. The support legs are notched to receive the support flange. A locking pin extends through the support leg and is positioned so s to selectively interfere with an outer periphery of the support flange. The locking pin is mounted for rocking or swiveling motion within the support leg and can be moved out of contact with the support flange, thereby allowing the support leg to pivot with respect to the support flange. A flat spring strip secured to an outer surface of the support leg biases the locking pin to a position engaging the support flange.