Abstract:
Disclosed is an intuitively operable rotation mechanism for a flip top table that includes an offsetting feature that provides aligned table legs when the table is in a use configuration while offsetting the legs when they are in a storage configuration. By offsetting the table legs in storage configuration, the height of the table legs can be more than one half of the length of the table. This feature is of particular importance for folding tables that are positioned at a standing height.

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to a folding leg mechanism, and more particularly to a folding leg mechanism that offsets the folded table legs when in a storage configuration while aligning the legs when in a use configuration. 
     BACKGROUND OF THE INVENTION 
     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 
     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 and an offsetting mechanism that provides aligned table legs when the table is in a use configuration and offset table legs when in a storage configuration. By offsetting the table legs in storage configuration, the height of the table legs can be more than one half of the length of the table. This feature is of particular importance for folding tables that are utilized by standing persons. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a lower perspective view of a table with legs in a use configuration. 
         FIG. 2  is a bottom view of a table with legs in a use configuration. 
         FIG. 3  is a side view of a table with legs in a use configuration. 
         FIG. 4  is a bottom view of a table with legs that have been moved to an offset position, but not a storage position. 
         FIG. 5  is a side view of a table with legs that have been moved to an offset position, but not a storage position. 
         FIG. 6  is a bottom view of a table with legs that have been moved to an offset storage position, but have not been secured in the storage position. 
         FIG. 7  is a bottom perspective view of a table with legs that have been moved to an offset storage position, but have not been secured in the storage position. 
         FIG. 8  is a bottom perspective view of a table with legs that have been secured in an offset storage position. 
         FIG. 9  is a bottom view of a table with legs that have been secured in an offset storage position. 
         FIG. 10  is a perspective view of a folding mechanism with a leg between a use and storage configuration. 
         FIG. 11  is a side perspective view of a folding mechanism with a leg between a use and storage configuration. 
         FIG. 12  is a second perspective view of a folding mechanism with a leg between a use and storage configuration. 
         FIG. 13  is a bottom view of a folding mechanism with a leg between a use and storage configuration. 
         FIG. 14  is a bottom perspective view of a folding mechanism secured in a use configuration. 
         FIG. 15  is a bottom view of a folding mechanism secured in a use configuration. 
         FIG. 16  is a side view of a folding mechanism secured in a use configuration. 
         FIG. 17  is a second side view of a folding mechanism secured in a use configuration. 
         FIG. 18  is a perspective view of a table leg highlighting the protrusion between the spring and the ring of pins. 
         FIG. 19  is a side view of a table leg showing the protrusion and the ring of pins. 
         FIG. 20  is an upper perspective view of a rotation mechanism with the top portion of the rotation mechanism removed. 
         FIG. 21  shows a top view of a rotation mechanism with a table leg locked in a use configuration. 
         FIG. 22  shows a top view of a rotation mechanism with a table leg offset from the use configuration. 
         FIG. 23  shows an isolated side view of the cylindrical sheet. 
         FIG. 24  is a perspective view of a rotation mechanism isolated from a table leg. 
         FIG. 25  is a second perspective view of a rotation mechanism isolated from a table leg. 
         FIG. 26  is a side view of a rotation mechanism isolated from a table leg. 
         FIG. 27  is a bottom view of a rotation mechanism isolated from a table leg. 
         FIG. 28  is a bottom perspective view of a rotation mechanism adapted to secure a table leg with a single vertical portion. 
         FIG. 29  is a bottom view of a rotation mechanism adapted to secure a table leg with a single vertical portion. 
         FIG. 30  is schematic view of a table top with rotation mechanisms. 
     
    
    
     DETAILED DESCRIPTION 
     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 having 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. 
       FIGS. 1-3  show views of a table top  5  secured to table legs  10  via rotation mechanisms  15 . The first vertical portions  20  of the distinct table legs are aligned along a geometric plane  30  and are equidistant from a linear horizontal edge  35  of the table top when the table legs  10  are in a use configuration. While not required, the illustrated table system is symmetrical such that each table leg  10  has a second vertical portion  40  that is aligned along another geometric plane  45  and the second vertical portions  40  located near, and equidistant from a second edge  50  of the table top  5 . The first vertical portion  20  of the table leg  10  is separated from the second vertical portion  40  by a horizontal portion  55  that passes through the rotation mechanisms  15 . 
     In  FIGS. 4 and 5 , the two table legs have been slid through the rotation mechanisms  15  such that the first vertical portion  20  of one leg is substantially further away (a first distance  60 ) from the edge  35  than the first vertical portion  20  of the other leg (a second distance  65 ). The first distance  60  is substantially greater than the second distance  65  in that the difference between the two distances produces a significant chance in the position of the circular collar and protrusion along the axis of rotation of the table leg. The difference between the first distance  60  and the second distance  65  is greater than the width  70  of the first vertical portion  20  to facilitate the legs over lapping upon each other. 
       FIGS. 6 and 7  show the table legs of  FIGS. 4 and 5  having been rotated such that the vertical portions ( 20  and  40 ) of the table legs  10  are located adjacent to the table top  5 . The table legs  10  in  FIGS. 6 and 7  are not secured in a storage configuration and the two first vertical portions  20  of the table legs are separated from the linear horizontal edge  35  by the first distance  60  and the second distance  65 , respectively. Since the differences of the first distance  60  and the second distance  65  is greater than the width  70  of the first vertical portion  20 , there is a slight gap  75  between the two first vertical portions  20 . 
       FIGS. 8 and 9  show the tables of  FIGS. 4-7  in a folded and secured position. The first vertical portions  20  of the two table legs  10  have moved closer to each other such that the gap shown in  FIGS. 6 and 7  between the table legs has been removed or substantially reduced. The movement of the table legs towards each other causes features in the rotation mechanisms  15  to secure the table legs in the storage position. To disengage the table legs from the storage position or configuration, the legs are moved away from each other to disengage the locking features in the rotation mechanisms. 
       FIGS. 10 through 13  show an isolated view of the rotation mechanism  15  interacting with a table leg  10 . The rotation mechanism includes a base  100  or plate adapted to be secured to the table top. In the illustrated example, the base  100  has a substantially rectangular shape, however it should be appreciated that other shapes such as circular or polygonal may be utilized. The base  100  may include holes or openings through which fasteners (such as screws) pass through and interconnect with the table top. Flanking the base  100 , and extending away from the table top, are a first sidewall  105  and a second sidewall  110 . A locking ring  115  or locking wall also extends downward away from the table top and is rigidly secured to the base  100 . The locking ring  115  includes a circular aperture  120  through which the horizontal portion  55  of the table leg  10  slides. The circular aperture  120  is substantially defined by the circumference of the horizontal portion  55  of the table leg and allows the table leg  10  to both slide through the circular aperture  120  and rotate within the aperture. Surrounding the circular aperture  120  are a plurality of openings  125  that extend through the locking ring  115 . As with the circular aperture  120 , the openings  125  extend through the locking ring  115  parallel to the axis of rotation  130  of the table leg. As shown in the figures, the openings  125  are substantially smaller than the circular aperture  120 . While the openings  125  are shown as circular, it should be appreciated that the openings  125  may be a variety of shapes. Between the locking ring  115  (locking wall) and the first sidewall  105  is a cylindrical sheet  135  or cylindrical piece partially circumscribing the horizontal portion  55  of the table leg, and located between the horizontal portion  55  and the base  100  of the rotation mechanism  15 . The cylindrical sheet  135  is substantially concentric with the horizontal portion  55  such that there is a substantially constant separation between the cylindrical sheet  135  and the horizontal portion  55 . At the rotation mechanism  15 , the table leg  10  includes a circular collar  140  with a diameter greater than the circular aperture  120 . While the diameter of the circular collar  140  is greater than that of the circular aperture  120 , the circular collar  140  has a smaller radius of curvature than the cylindrical sheet  135 . From the circular collar  140 , a plurality of pins  145  extend, parallel to the axis of rotation  130 , towards the locking ring  115 . The pins  145  have shapes that are substantially defined by the shape of the openings  125 , and are slightly smaller than the openings such that they are able to be secured within the openings  125  when the table legs are in a use configuration. In one embodiment, the ends of the pins are slightly tapered to facilitate them entering into the openings and providing a fine adjustment to the rotational configuration of the table legs. The interconnection of the pins  145  in the openings  125  provides additional stability to the table legs when the table is in use. However, the pins  145  are not secured in the openings  125  of the locking ring  115  when the table legs are secured in a storage configuration. Located between the first sidewall  105  and the circular collar  140  is a spring  150  that acts to bias the circular collar  140  towards the locking ring  115 . While the illustrated example shows a refined compact rotation mechanism, it should be appreciated that the spring  150  may be located distant from the remainder of the rotation mechanism. Highlighted in  FIG. 11 , the illustrated first sidewall  105  and the second sidewall  110  are asymmetric relative to the axis of rotation  130  of the table leg. Each of the sidewalls ( 105 ,  110 ) has a long edge  155  extending from the horizontal portion  55  of the table leg to the base  100 , and a short edge  160  extending from the table leg to the base  100 . The asymmetrical shape of the sidewalls allows for the horizontal portion  55  of the table leg to be positioned closer to the edge of the table top. The overlapping nature of the table legs allows for substantially longer table legs to be utilized than would otherwise be feasible. By positioning the horizontal portions of the table legs closer to the edge of the table top, the stability of the table while in a use configuration is increased. 
       FIGS. 14 through 17  illustrate the rotation mechanism  15  where the circular collar  140  is pressed against the locking ring  115  such that the pins  145  are secured within the openings  125 . The spring  150  continues to press the circular collar  140  towards the locking ring  115  to prevent the table legs from accidentally disengaging from the use configuration.  FIG. 16  is a side view of the rotation mechanism that shows the cylindrical sheet  135  with a track  165  that surrounds a protrusion  170  of the horizontal portion  55  of the table leg that is radially aligned to the axis of rotation of the table leg.  FIG. 17  highlights the profile of the second sidewall  110  that has a concave surface  175  between the long edge  155  and the short edge  160 . The concave surface  175  is substantially defined by the circumference of the table leg, and may act to further secure the table leg to the table top  5 . The first sidewall  105  also includes a similar concave surface that is defined by the circumference of the horizontal portion of the table leg. 
       FIGS. 18 and 19  show a portion of the table leg and spring in isolation. The circular collar  140  fully circumscribes the horizontal portion of the table leg. The spring  150  is located near the circular collar  140  and the protrusion  170  is located between the spring  150  and the circular collar  140 . While the protrusion  170  is located between the collar and spring in  FIG. 18 , it should be noted that the protrusion  170  extends directly from the circular collar  140  in  FIG. 19 . The protrusion  170  is aligned along a radius  180  of the axis of rotation  130  such that the protrusion has a length that is defined by a line extending perpendicularly from the axis of rotation  130 . 
       FIGS. 20 through 23  highlight the track  165  in the cylindrical sheet  135  of the rotation mechanism. The base  100  of the rotation mechanism  15  has been removed to better illustrate the cylindrical sheet  135 . The track  165  of the cylindrical sheet  135  includes a cylindrical portion  185  that rotationally extends along a geometric arc with the axis of rotation  130  as the center point. From the cylindrical portion  185  of the track  165  a first linear portion  190  extends perpendicularly away from the cylindrical portion  185  parallel to the axis of rotation  130  of the table leg. A second linear portion  195  also perpendicularly extends away from the cylindrical portion  185  distant from the first linear portion  190 . The first linear portion  190  extends a first distance  200  while the second linear portion only extends a second distance  205 . The difference between the first distance  200  and the second distance  205  is approximately one half of the width  70  of the table leg such that when the table legs are in a storage configuration they are kept in close proximity to each other. When the table legs are in the use configuration, the protrusion  170  is at the end of the first linear portion  190  of the track  165  that is closest to the locking ring  115  while when the table legs are in the storage configuration the protrusion  170  is located at the end of the second linear portion  195  that is closest to the locking ring  115 . The spring in the rotation mechanism acts to bias the protrusion  170  towards the locking ring  115  (locking wall). To change the legs from a use configuration to a storage configuration (or vice versa), the legs are moved against the spring until the protrusion  170  is able to enter the cylindrical portion  185  of the track  165 . Only once the protrusion has reached the cylindrical portion  185  of the track  165  are the table legs able to be rotated. The legs are then rotated until the protrusion reaches the opposite linear portion of the track at which point further rotation of the leg is not possible. Once at the opposite linear portion, the spring biases the protrusion  170  towards the locking ring  115  and the linear portion prevents rotation of the table leg. If the table legs are in the use configuration, the pins of the circular collar and the openings in the locking ring also act to prevent rotation of the table legs. 
       FIG. 23  shows a side view of the cylindrical sheet  135 . A first geometric radius  181  and a second geometric radius  182  perpendicularly extend from the axis of rotation  130  through the centers of the first linear portion  190  and the second linear portion  195 , respectively. The first and second geometric radiuses ( 181 ,  182 ) are at a right angle to each other such that one quadrant  183  about the axis of rotation  130  is defined by the two radiuses. The cylindrical portion  185  of the track  165  fully spans the quadrant  183  defined by the two radiuses. By spanning a single quadrant, the cylindrical portion  185  of the track  165  allows the table legs to be rotated 90 degrees, and no more. 
       FIGS. 24 through 27  show an isolated view of the rotation mechanism  15  without the horizontal portion of the table leg or the spring. Without the table leg, the circular aperture  120  of the locking ring  115  is shown having a diameter that is substantially similar to the concave surface  175  of the second sidewall  110 . The first sidewall  105  also has a concave surface that is substantially similar to the circular aperture  120  of the locking ring  115 . The illustrated cylindrical sheet  135  is shown having a half circular shape, however it should be appreciated that in an alternate embodiment the cylindrical sheet fully encloses a portion of the horizontal portion of the table leg. In another embodiment, the cylindrical sheet is less than half a circle in circumference, and in yet another embodiment, the cylindrical sheet has a circumference that is only slightly larger than the cylindrical portion of the track. In  FIGS. 24-27 , the base  100  is shown as being asymmetrical about the cylindrical sheet  135 , however in another embodiment the base  100  is symmetrical. Additionally, the base  100  may be composed of several components that act to secure the rotation mechanism to the table top. 
       FIGS. 28 and 29  show an alternate embodiment of a rotation mechanism adapted to secure a table leg with a single vertical portion. The rotation mechanism shown in  FIGS. 28 and 29  has all the components of the rotation mechanism shown in  FIGS. 1 through 27  with the addition of a second locking ring  115  located adjacent to the first sidewall  105 . The second locking ring acts primarily as a guide surface for the horizontal portion of the table leg and prevents wobble of the leg. To reduce wobble, the first and second locking rings are preferably spaced as far from each other as possible. As shown in  FIG. 28 , the first and second locking rings  115  include openings  125 . The openings  125  of the second locking ring do not interact with the pins  145  of the table leg and may be omitted. However, to reduce the variety of pieces that need to be manufactured, it is expected that at in at least some embodiments all of the locking rings will be created with openings  145 . In the illustrated example, the locking rings  115  are identical to each other and provide the rotation mechanism with a refined appearance; however, it should be appreciated that in other embodiments the two locking rings may have substantially different shapes from each other. 
       FIG. 30  shows a schematic view of two rotation mechanism secured to a table top  5 . The table top has a first linear horizontal edge  35 , and the rotation mechanisms each have cylindrical sheets  135  with tracks having cylindrical portions  185 , first linear portions  190 , and second linear portions  195 . In mechanism show in the upper portion of the figure, the first linear portion  190  and the second linear portion  195  are both a first length  210  from the linear horizontal edge  35 . They are equidistant from the edge. In comparison, the first linear portion  190  of the lower rotation mechanism is a second length  215  from the linear horizontal edge  35  while the second linear portion  195  is a third length  220  from the edge. The third length is substantially greater than the second length. In the upper rotation mechanism, a spring would bias the protrusion away from the linear horizontal edge  35 , while the lower mechanism would have a spring biasing another protrusion on the table leg towards the linear horizontal edge  35 . 
     The inventors contemplate several alterations and improvements to the disclosed invention. Other alterations, variations, and combinations are possible that fall within the scope of the present invention. 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.