Abstract:
The present invention provides an improved latching mechanism for table legs. While maintaining the benefits of standard folding mechanisms, the mechanism of the present invention also achieves many benefits including improved table rigidity, an intuitively operable release mechanism, an easily constructed mechanism with as little as three molded pieces and a spring, a single release action to release the mechanism from both a “use” and “folded” configuration, and four spatially separated latching points for each of the “use” and “folded” configurations. Additionally the present invention provides a mechanism meets or exceeds government and industry standards while having a refined appearance.

Description:
CROSS-REFERENCE TO COPENDING APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Patent Application 61/374,787 entitled “Flip and Fold Mechanism” filed Aug. 18, 2010 by Michael John Ensley, the contents of which are herein incorporated by reference; this application also claims any benefit available from U.S. patent application Ser. No. 12/917,665 filed Nov. 2, 2010. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates generally to a latching mechanism, and more particularly to a latching mechanism for a table leg latch assembly having improved stability, robustness, and ease of manufacture. 
       BACKGROUND OF THE INVENTION 
       [0003]    Folding tables are commonly used in commercial and residential settings where tables are intermittently needed, or the tables need to be moved on a regular basis. Tables in a storage configuration take up less space and are often stackable on other folded tables, thus reducing the amount of storage space needed. Latching mechanisms have been used to lock the table legs in either a storage or use configuration, however these mechanisms often do not provide sufficient rigidity and may cause the table to wobble. Additionally, latching mechanisms often involve numerous small interconnected pieces that may jam due to the buildup of dirt and debris, or be damaged when the tables are transported or stored. 
       SUMMARY OF THE INVENTION 
       [0004]    The present invention provides an improved latching mechanism for tables with foldable legs. While maintaining the benefits of standard mechanisms, the mechanism of the present invention also achieves many benefits including an intuitively operable release mechanism, a single release action for both the “use” and “storage” configurations, improved table rigidity with two spatially separated latching points in both the “use” and “storage” configurations, a robust design that requires as little as three separate manufactured pieces. Additionally the present invention provides a mechanism that meets or exceeds government and industry standards and has a refined appearance. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]      FIG. 1  is a side perspective view of a table leg folding mechanism in a use configuration. 
           [0006]      FIG. 2  is a side perspective view of the table leg folding mechanism of  FIG. 1  in a storage configuration. 
           [0007]      FIG. 3  is a side perspective view of a base for a table leg folding mechanism. 
           [0008]      FIG. 4  is a front perspective view of a base for a table leg folding mechanism. 
           [0009]      FIG. 5  is a side perspective view of a latch for a table leg folding mechanism. 
           [0010]      FIG. 6  is a front perspective view of a latch for a table leg folding mechanism. 
           [0011]      FIG. 7  is a bottom perspective view of a rotor for a table leg folding mechanism. 
           [0012]      FIG. 8  is a top perspective view of a rotor for a table leg folding mechanism. 
           [0013]      FIG. 9  is a side view of a rotor for a table leg folding mechanism. 
           [0014]      FIG. 10  is a side perspective view of a cable release for a table leg folding mechanism. 
           [0015]      FIG. 11  is a top perspective view of a cable release for a table leg folding mechanism. 
           [0016]      FIG. 12  is a side perspective view of the latch and rotor of the table leg folding mechanism of  FIG. 1  in a use configuration. 
           [0017]      FIG. 13  is a side perspective view of the latch and rotor of the table leg folding mechanism of  FIG. 1  in a storage configuration. 
           [0018]      FIG. 14  is a side view of the latch and rotor of the table leg folding mechanism of  FIG. 1  in a use configuration. 
           [0019]      FIG. 15  is a side view of the latch and rotor of the table leg folding mechanism of  FIG. 1  in a storage configuration. 
           [0020]      FIG. 16  is a side view of the latch and rotor of the table leg folding mechanism of  FIG. 1  in a transitional configuration between a use configuration and a storage configuration. 
           [0021]      FIG. 17  is a side perspective view of a right circular cylindrical arc. 
           [0022]      FIG. 18  is a rear perspective view of the table leg folding mechanism of  FIG. 1  in a use configuration. 
           [0023]      FIG. 19  is a rear perspective view of the table leg folding mechanism of  FIG. 1  in a storage configuration. 
           [0024]      FIG. 20  is a side view of the table leg folding mechanism of  FIG. 1  in a use configuration. 
           [0025]      FIG. 21  is a side view of the table leg folding mechanism of  FIG. 1  in a storage configuration. 
           [0026]      FIG. 22  is a front view of the table leg folding mechanism of  FIG. 1  in a use configuration. 
           [0027]      FIG. 23  is a front view of the table leg folding mechanism of  FIG. 1  in a storage configuration. 
           [0028]      FIG. 24  is a rear view of the table leg folding mechanism of  FIG. 1  in a use configuration. 
           [0029]      FIG. 25  is a rear view of the table leg folding mechanism of  FIG. 1  in a storage configuration. 
           [0030]      FIG. 26  is a side see through view of the table leg folding mechanism of  FIG. 1  in a use configuration. 
           [0031]      FIG. 27  is a perspective view of the table leg folding mechanism of  FIG. 1  in a use configuration secured to a table leg. 
           [0032]      FIG. 28  is a perspective view of the table leg folding mechanism of  FIG. 1  in a storage configuration secured to a table leg. 
           [0033]      FIG. 29  is a perspective view of the table leg folding mechanism of  FIG. 1  in a storage configuration secured to a table leg. 
           [0034]      FIG. 30  is a perspective view of a plurality of table leg folding mechanisms of  FIG. 1  in a storage configuration, wherein each mechanism of  FIG. 1  is secured to both a table leg and a tabletop. 
           [0035]      FIG. 31  is a perspective view of a plurality of table leg folding mechanisms of  FIG. 1  in a use configuration, wherein each mechanism of  FIG. 1  is secured to both a table leg and a tabletop. 
           [0036]      FIG. 32  is a top perspective view of a leg folding mechanism that includes a cable release device. 
           [0037]      FIG. 33  is a top perspective view of a leg folding mechanism that includes a cable release device, wherein the mechanism is shown without the base and rotor for illustrative purposes. 
           [0038]      FIG. 34  is a perspective view of a plurality of leg folding mechanisms that each includes a cable release device. 
           [0039]      FIG. 35  is a top perspective view of a table secured to a plurality of leg folding mechanisms that each includes a cable release device, wherein all of the cables extend to a central box. 
       
    
    
     DETAILED DESCRIPTION 
       [0040]    The present invention may be used with any type of leg and any type of top surface and is particularly suited for tables and applications requiring a lightweight, rigid, and robust mechanism with an intuitively operated release action. The improved folding mechanism may be used with objects with folding legs such as chairs and tables, stadium seating or benches. However, for descriptive purposes, the present invention will be described in use with a table. 
         [0041]      FIGS. 1-2  show views of a folding mechanism  10  having a base  15 , a rotor  20  adapted to be secured to a table leg, and a latch  25 . The rotor  20  and the latch  25  are both rotatably secured to the base at unique locations such that the rotor  20  and the latch  25  have unique axes of rotation.  FIG. 1  illustrates the folding mechanism in a use configuration and  FIG. 2  illustrates the folding mechanism in a storage configuration. The rotor  20  and the table leg are rotated approximately 90 degrees relative to the base between the storage and use configurations. In both the use and storage configurations, the latch and portions of the base hold the rotor and table leg in the use or storage configuration. The latch may be selectively withdrawn from the rotor to enable the rotor to transition from the use or storage configurations. 
         [0042]    A spring  27  forces the latch  25  towards the rotor  20  to prevent the latch from accidentally disengaging from the rotor. In addition to helping keep the rotor in the storage or use configurations, when the rotor is transitioned from the storage configuration to the use configuration (or from the use configuration to the storage configuration) the springs acts to automatically interlock the latch with the rotor once the rotor has been rotated to one of the orientations. Although a tension spring extending between the latch and rod is show in the illustrated example, various other devices and configurations may be used to force the latch to rotate towards the rotor. For example, a compression spring between the base and the latch may act to rotate the latch. Alternatively, a torsion spring may be wrapped around the axis of rotation for the latch such that is presses upon both the base and the latch. 
         [0043]    A base, shown isolated in  FIGS. 3 and 4  for clarity, is configured to be rigidly secured to a structure, such as a table top, through a fastener such as screws, nails, or an adhesive. The base includes two walls  30  that flank and are rotatably secured to the rotor  20  and parts of the latch  25 . The walls  30  extend from an expanded table mount  35  and taper towards a leg end  40  of the wall. The expanded area of the table mount provides a large contact surface between the latching mechanism and the tabletop that helps to improve the stability of the table. In one embodiment, the table mount portion  35  of the base includes a plurality of apertures through which screws or nails are passed through to secure the base to a tabletop. 
         [0044]    In the illustrated example, walls  30  are tapered down to a width that is substantially similar to the width of the rotor. Additionally, the taper of the walls provides a smoothed surface and reduces the number of sharp edges and snag points on the latching mechanism. In the embodiment of the base shown in  FIGS. 3 and 4 , the walls include a first set of holes  42  adapted to rotatably connect to the rotor and a second set of holes  45  adapted to rotatably connect to the latch. The walls illustrated in  FIGS. 3 and 4  also include base protrusions  50  adapted to contact the rotor and prevent rotation of the rotor in both the storage and use configurations. In an alternate embodiment of the base, the wall may include a third set of holes adapted to receive a rod that extends between the two walls and, like the protrusions, acts to prevent rotation of the rotor in both the use and storage configurations. 
         [0045]    In the illustrated example of the base, the table mount portion  35  of the base includes an extended groove  55  that extends parallel to the interior sides of the two walls. The extended groove may act to receive a portion of the rotor and provides an additional contact area when the latching mechanism is in a storage configuration. Additionally, the extended groove may be structured to receive a portion of a table leg and thus allow the table leg to be folded closer to the tabletop when the table is in the storage configuration. 
         [0046]    The base, the latch, and the rotor may be constructed from a wide variety of materials such as plastics, metals, natural materials, and composite materials. Materials contemplated by the inventor include molded glass, fiberglass, nylon, glass material, metal, cold rolled steel, hot rolled pickled and oiled steel, stamped steel, stamped aluminum, carbon/nylon reinforced textile sheets, amarid, polyester, and carbon fiber. For components created by an injection molding process, the resins contemplated by the inventor include epoxy, unsaturated polyester, urethane acrylate, vinyl ester, phenol, polyurethane, a thermoplastic resin, nylon 6, nylon 66, nylon 12, PBT, PET, polycarbonate, polyacetal, polyphenylene sulfide, polyether ether ketone, polyether sulfide, polyphenylene oxide, modified polyphenylene oxide, polypropylene, polyvinyl chloride, ethylene-vinyl acetate copolymer, polystyrene, acrylonitrile-butadiene-styrene copolymers (ABS), 6, 11, 12, 6-6 and 6-10 polyamides, poly(ether amide) sequenced copolymer, fluorinated polymers, polysulfone, polyethersulfone, polycarbonate, polyetheretherketone, polyphenylene sulfur, polyetherimide, and polyphenylene ether. Coatings such as polytetrafluoroethylene (Telfon®) may be used in the first set of holes  40  and the second set of holes  45  of the base in order to reduce friction when the latching mechanism is transitioned from a use configuration to a storage configuration. 
         [0047]    A latch, shown isolated in  FIGS. 5 and 6  for clarity, includes a main section  60  between a first sidewall and second sidewall  70 . In the illustrated example, each of the sidewalls includes a sidewall protrusion  75  that is adapted to rotatably connect into the second set of holes in a base of the latching mechanism. Each sidewall  70  also includes a catch  80  configured to interconnect with a rotor. A handle  85  extends from the main section and provides an area for a user to grasp in order to disengage the latch from the rotor. Also extending from the main section  60  of the latch is a torsion section  90  with a spring aperture  95  adapted to be secured to a spring that pushes or pulls the latch towards the rotor. The torsion section  90  also includes a cable release aperture  97  adapted to be secured to a wire release mechanism that allows a user to remotely disengage the latch from the rotor or simultaneously disengage multiple latches from multiple rotors. In the illustrated example of the latch, the handle and intersections of the sidewalls and main section are curved to provide a refined appearance and also to reduce the number of sharp edges on the latching mechanism. 
         [0048]    A rotor, shown isolated in  FIGS. 7-9  for clarity, includes a primary section  100  between two curved end walls  105 . Each curved end wall  105  includes an end wall protrusion  110  adapted to be rotatably secured into one of the holes in the first set of holes of the base. The rotor, when secured to the base, is configured to rotate around an axis of rotation  115  extending between the end wall protrusions of the rotor. The primary section  100  and a latching surface  120  cooperate to circumscribe the curved end walls of the rotor. Each of the latching surfaces includes an inner radial surface  125  that is located at substantially an arc of a first right circular cylinder  127  having a central axis at the axis of rotation  115  and a first radius  130 . Each of the latching surfaces  120  also includes an outer radial surface  135  located at substantially on an arc of a second right circular cylinder  137  having a central axis at the axis of rotation  115  and a second radius  140 . In the illustrate example of a rotor, the arcs of the circular cylinders have central angle of approximately 80 degrees. In other embodiments of rotor, the arcs of the circular cylinders have central angles of at least 30 degrees. 
         [0049]    Between the inner radial surface  115  and the outer radial surface  135  on each latching surface  120  is a first protrusion surface  142  adapted to interlock with the protrusion or rod of the base. On the latching surface  120 , between the inner radial surface  125  and the primary section  100  is a second protrusion surface  143  adapted to interlock with the protrusion or rod of the base. In the illustrated embodiment, the first protrusion surface  142  and the second protrusion surface  143  are each substantially defined by a plane that includes the axis of rotation  115  such that the intersections of the first protrusion surface and both the inner radial surface and outer radial surface are substantially perpendicular. Each latching surface  120  also includes a notch area  145  with an opening  146  that is distant from both the first and second protrusion surfaces ( 142  and  143 ) and located between the outer radial surface  135  and the primary section of the rotor. The notch area is configured to interlock with the catch of a latch. The arc length of the inner radial surface is substantially longer than the height of the catch  80  and the width of the base protrusion such that the catch and base protrusions are not able to individually contact both the first and second protrusion surface  142  and  143  simultaneously. 
         [0050]    The primary section of the rotor may include a plurality of leg apertures  150  configured through which fasteners may be used to secure a table leg to the rotor. The rotor may also include a groove protrusion  152  that is configured to interlock with the main groove of the base when the latching mechanism is in a storage configuration, and a latch protrusion  153  that is configure to be adjacent to the latch when the rotor is in the use configuration. 
         [0051]    A cable mechanism  160 , shown isolated in  FIGS. 10 and 11  for clarity, having a cable stand  165  holding a cable housing  170  with a cable  175 . The cable stand  165  may be secured to the base to enable a user to disengage the latch from the rotor without directly contacting the latch. The cable stand  165  includes a cable aperture  180  through which a portion of the cable housing is secured. The cable aperture is sized to prevent the cable housing from moving towards the latch when the cable is pulled. A washer, disc  185 , or other object with a diameter larger than the diameter of the cable release aperture in the latch, may be secured to the end of the cable to pull on the latch when the cable is pulled. Alternatively, the cable may be secured directly to the latch. In the illustrated example, the cable stand includes screw apertures  190  through which fasteners may be threaded to the base of the latching mechanism. However, in other embodiments, the cable stand may be secured to the base using adhesive or another fastener that does not require the use of apertures in the cable stand  165 . 
         [0052]    In  FIGS. 12-15 , a cable mechanism, latch and rotor are shown isolated for clarity with a latching rod  200 , a rotor rod  205 , and a protrusion rod  210  configured to extend between walls of the base. The latch  25  is secured to, and rotates about, the latching rod  200 . The rotor  20  is secured to, and rotates about, the rotor rod  205 . The protrusion rod  210  is configured to contact either the first or second protrusion surface of the rotor when the latching mechanism is the storage configuration ( FIGS. 13 and 15 ) or use configuration ( FIGS. 12 and 14 ). 
         [0053]      FIG. 16  illustrates the latch and rotor of  FIGS. 12-15  in an intermediate configuration between the use configuration and the storage configuration. The latch has been rotated from the first position shown in  FIGS. 12-15  to a second position that allows the rotor to rotate between the storage and use configurations. 
         [0054]      FIG. 17  illustrates an example of a right circular cylindrical arc  154  having a third radius  155  from a central axis  156  and an arc length  157  that is equal to twice the third radius  155  times Pi times the central angle  158  divided by 360 degrees. In an exemplary embodiment of the invention, the inner and outer radial surfaces of the latching surface of the rotor are substantially defined by and encompass a circular cylindrical arc. 
         [0055]      FIGS. 18-25  show additional views of the latching mechanism in both the storage and use configurations.  FIG. 26  shows a side-see through view of the latching mechanism further illustrating the relationships between the latch, the rotor, and the base. 
         [0056]      FIGS. 27-29  illustrate a latching mechanism connected to a table leg  215 . In the illustrated example, the table leg  215  only connects to a portion of the leg apertures  150 . The primary section of the rotor may include more apertures than needed for a single leg in such that various styles of table legs may be connected to a single style of latching mechanism. 
         [0057]      FIGS. 30 and 31  illustrate four latching mechanisms  10  of  FIG. 1  securing four table legs  215  to a tabletop  220 . In the illustrated example, four latching mechanisms are secured to the table top, however fewer or additional latching mechanisms may be used. 
         [0058]      FIGS. 32 and 33  illustrate a latching mechanism that is remotely operable via a cable mechanism. A cable  175  passes through both the cable aperture in the cable stand and the cable release aperture  97  in the latch and acts to draw the latch toward the cable stand and away from the rotor. 
         [0059]      FIGS. 34 and 35  illustrate multiple latching mechanisms on a tabletop  220  that each has a cable mechanism that allows a user to disengage the latch from the rotor without directly contacting the latch. The cable mechanisms are connected to a cable pull  225  that simultaneously pulls multiple cables and allows a user to simultaneously disengage multiple latches from multiple rotors. 
         [0060]    The inventor contemplates several alterations and improvements to the disclosed invention. The latching and release mechanisms may further include protective and/or decorative coatings such as paint. Other alterations, variations, and combinations are possible that fall within the scope of the present invention. For example, a spring may be added between the base and the rotor so that the mechanism will automatically transition from a “use” position to a “folded” position when the latch is released from the rotor. Although various embodiments of the present invention have been described, those skilled in the art will recognize more modifications that may be made that would nonetheless fall within the scope of the present invention. Therefore, the present invention should not be limited to the apparatus described. Instead, the scope of the present invention should be consistent with the invention claimed below.