Abstract:
A dual release locking system for locking and unlocking the foldable leg members of a sign supporting stand. For deployment, a locking pin can be retracted by the stepping action of a worker&#39;s foot or pulled by hand. Consequently, this same pin can be retracted for retrieval by a kicking action of a worker&#39;s foot or pulled by hand.

Description:
CROSS-REFERENCE TO RELATED APPPLICATION 
       [0001]    None 
       FEDERALLY SPONSORED RESEARCH 
       [0002]    Not Applicable 
       SEQUENCE LISTING OR PROGRAM 
       [0003]    Not Applicable 
       STATEMENT REGARDING COPYRIGHTED MATERIAL 
       [0004]    Portions of the disclosure of this patent document contain material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure as it appears in the Patent and Trademark Office file or records, but otherwise reserves all copyright rights whatsoever. 
       BACKGROUND 
       [0005]    The present invention pertains generally to the field of portable assemblies such as highway safety signs and light assemblies commonly fitted with pivoting legs to facilitate handing and storage, and more particularly-to an adjustable leg system able to accommodate uneven terrain. 
         [0006]    Several portable assemblies with pivoting legs have been developed in the art. U.S. Pat. No. 4,954,008 to Dicke discloses a quick release mechanism for locking a tubular leg member of, for example, a mounting base for outdoor signs and barriers. The quick release mechanism includes a lever arm, a pin and a resilient member. The lever arm is pivotally attached to the tubular leg. The pin passes through and extends beyond both sides of the tubular leg and loosely rides within a slot at the operating end of the lever arm. The resilient member fits beneath the handle end of the lever arm being in tensional contact with the outer surface of the leg and the bottom surface of the lever arm. To lock the leg in any position, such as in either the horizontal support position or in the upright compact position, the pin is pushed inwardly to an engaged position in the leg flange by the operating end of the lever arm. The pin is unlocked by pressing on the handle end of the lever arm which pulls the pin out of the engaged position in the leg flange. 
         [0007]    U.S. Pat. No. 5,340,068 to Sarkisian discloses a release mechanism for a locking, pivotable leg for an assembly. The release mechanism includes a release pin having an enlarged head and transmission means to transmit movement of the release pin to the locking element moving it from its operative locking position. The transmission means includes a release pin spring shoulder, a locking pin spring groove and a pin slot in the leaf spring disposed to engage these two components. Movement of the release pin causes the release pin spring shoulder to deflect the leaf spring, which deflection is transmitted into movement of the locking pin in turn disengaging the locking pin from the locking pin hole in the base bracket, allowing the leg to pivot freely. 
         [0008]    U.S. Pat. No. 5,611,509 to Kulp discloses a quick release mechanism for securing a member to a structure, such as a support leg to a sign stand. The member includes a slot having a bottom surface and the structure has a slot having an open top end. A latch member releasably attaches the member to the structure, and is adapted to extend axially through both the member and structure slots, so that a proximal portion of the latch member extends forwardly of the member slot and a distal portion of the latch member extends rearward into the structure slot. When the latch member proximal portion is actuated downwardly, its distal portion swings upwardly through the open top end of the structure slot, thereby disengaging from the structure slot and releasing the member so that it may pivot relative to the structure. 
         [0009]    These systems, when deployed, must be inverted to release the legs for folding and storage. Due to the importance of worker safety, there is a need for a simple and reliable release system that works easily and quickly. 
         [0010]    It is therefore an object of the present invention to provide a release system for locking and unlocking the foldable tubular leg members of a portable structure. The release system of the present invention can be operated by users without diverting their attention from their surroundings. 
         [0011]    A further object of the invention is to provide a dual release system. For deployment, a lock pin can be retracted by the stepping action of a user&#39;s foot or pulled by hand. The same pin can be retracted for retrieval by a kicking action of a worker&#39;s foot or pulled by hand. 
         [0012]    A further object is to provide a a dual release system that can be reliably operated by a highway worker without diverting attention away from the highway traffic adjacent to the work zone. 
         [0013]    A further object is to provide a dual release system that is appropriate for all portable traffic signs and highway lights. These and other objects of the present invention will become better understood with reference to the appended Summary, Description, and Claims. 
       SUMMARY 
       [0014]    The present invention is a dual-release locking mechanism to be used in conjunction with a sign supporting stand. The sign supporting stand comprises a mast and a plurality of upwardly foldable and radially extending legs pivoted at the bottom of the mast. Each leg is incorporated with an individual locking system, which comprises a vertical plate member disposed alongside of the leg, a first locking mechanism for engaging the leg to the plate member at various locking positions as the leg is rotated about the pivot; the first locking mechanism also disengages the leg from a locking position. The locking system further comprises a second locking mechanism for operating the first mechanism wherein the leg can be engaged to the plate member at the various locking positions. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0015]      FIG. 1  is a perspective view of the dual release locking system of the present invention in a sign supporting stand, with the legs deployed. 
           [0016]      FIG. 2  is a partial perspective view of the dual release locking system of the present invention in a sign supporting stand, with the legs folded and sign moved 
           [0017]      FIG. 3  is an enlarged fragmentary perspective view of the dual release locking system Illustrated in  FIG. 2 . 
           [0018]      FIG. 4  is an enlarged fragmentary perspective view of the dual release locking system illustrated in  FIG. 1 . 
           [0019]      FIG. 5  is an enlarged sectional view taken on line  20 - 20  of  FIG. 3 . 
           [0020]      FIG. 6  is an enlarged operated sectional view of the dual release locking system. 
           [0021]      FIG. 7  is an enlarged sectional view taken on line  30 - 30  of  FIG. 5 . 
           [0022]      FIG. 8  is an enlarged partial sectional view taken on line  10 - 10  of  FIG. 1 . 
           [0023]      FIG. 9  is an enlarged partial sectional view taken on line  40 - 40  of  FIG. 8 . 
           [0024]      FIG. 10  is a perspective view of a sign supporting stand with an alternate base having a flexible shock absorbing sprung mast. 
       
    
    
     FIGURES—REFERENCE NUMERALS 
       [0000]    
       
           1  . . . Support Stand 
           2  . . . Leg 
           3  . . . Base 
           4  . . . Mast 
           5  . . . Sign 
           6  . . . Bolt 
           7  . . . Head of the Pin 
           8  . . . Hole 
           11  . . . Direction of the Kicking Force 
           12  . . . Direction of the Pulling Force 
           13  . . . Locking Pin 
           14  . . . Supporting Block 
           16  . . . Reaction Boss 
           21  . . . Compression Spring 
           22  . . . Ring 
           23  . . . Disengaging Member 
           24  . . . Hole in the Leg 
           25  . . . Sliding wedge-faced member 
           26  . . . Engaging wedge-faced member 
           27  . . . Screw 
           29  . . . Hook 
           31  . . . Wedge Pin 
           32  . . . Slot 
           33  . . . Tension Spring 
           36  . . . Skirt 
           37  . . . Guide Edge 
           42  . . . Plate Assembly 
           43  . . . Mast Adapter 
           44  . . . Side Member 
           60  . . . Elongated Base 
           62  . . . Shock-absorbing Springs 
           64  . . . Mast of the Additional Embodiment 
       
     
       DETAILED DESCRIPTION 
       [0057]    Referring to the drawings, a preferred embodiment of sign supporting stand is illustrated and generally indicated as  1  in  FIGS. 1 through 10 . The stand  1  is preferably used for supporting traffic signs and the like. The stand  1  comprises pivot-able legs  2  which incorporate a dual-release locking system of the present invention. 
         [0058]    Referring to  FIGS. 1 and 2 , the stand  1  includes a base  3 , with legs  2 , mast  4 , and sign  5 . As arrows  11  and  12  show the direction of operation, a leg  2  is released by a user&#39;s foot engaging sliding wedge-faced member  25  with a longitudinal kicking action  11  or by hand pulling a locking pin  13  at  12 . As shown in  FIG. 2 , a folded and locked stand  1  is held vertical and its legs  2  released by the sliding wedge-faced member  25  with a vertical steeping action  11  or by hand pulling the pin at  12 . 
         [0059]    Enlarged perspective  FIG. 3  and  FIG. 4  show legs  2  pivoting on bolt  6  through base  3 . The head  7  of the pin  13  protrudes through a hole  8   c  to lock leg  2  in a vertical (zero degree) position, for storage as seen in  FIG. 3 .  FIG. 4  shows the legs  2  deployed and locked at  8   a  (90 degrees) for sitting on level ground. For uneven ground the legs  2  are deployed and locked at  8   b  (95 degrees). 
         [0060]    A novel feature of this present invention is the sliding wedge-faced member  25  which slides along leg  2  guided by a pair of skirts  36  and retained by a wedge pin  31  which rides in slot  32 . The sliding wedge-faced member  25  is pushed at  11  to slip under an engaging wedge-faced member  26  thereby lifting it and consequently the pin  13 . Turning to  FIG. 5 , a sectional view and an operated sectional view  FIG. 6  reveals a disengaging member  23  secured to the top of engaging wedge-faced member  26  by screws  27 , and extending through a hole  24  in leg  2  to fit under a compression spring  21  and a ring  22  on the pin  13  retracting said pin  13  and its end  7 . The sliding wedge-faced member  25  is returned to its original position by a tension spring  33  connected to pin  31  and to hook  29  in the leg  2 . Force  11  through the wedges is counteracted by a reaction boss  16  which is secured by a bolt and a nut inside of leg  2 . The disengaging member  23  slides and pushes against a supporting block  14  attached to the pin  13 . The block  14  in turn slides and pushes against the boss  16  allowing the pin  13  to retract without binding. 
         [0061]    Sectional view  FIG. 7  clearly shows the guide skirts  36  on the sliding wedge-faced member  25  beside leg  2 . The sliding wedge-faced member  25  has on its front face guide edges  37  to center and guide the engaging wedge-faced member  26 . 
         [0062]      FIGS. 8 and 9  show another novel feature of the present invention which is the one piece plate assembly  42  of base  3 . This plate assembly  42  is cut and formed to extend as an integral front lip. A mast adapter  43  and a side member  44  are welded between two side plates  42 . 
         [0063]    An alternative design for a base incorporating a flexible mast is shown in the perspective view in  FIG. 10 . This assembly incorporates the release mechanism of the present invention on legs  2  with an elongated base  60  and shock absorbing springs  62  connecting to the mast  64 . 
         [0064]    All features disclosed in this specification, including any accompanying claims, abstract, and drawings, may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features. 
         [0065]    Any element in a claim that does not explicitly state “means for” performing a specified function, or “step for” performing a specific function, is not to be interpreted as a “means” or “step” clause as specified in 35 U.S.C. §112, paragraph 6. In particular, the use of “step of” in the claims herein is not intended to invoke the provisions of 35 U.S.C. §112, paragraph 6. 
         [0066]    Although preferred embodiments of the present invention have been shown and described, various modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustration and not limitation.