BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an end elevational view of a folding table in a use position according to the principles of the present invention;
FIG. 2 is an end elevational view of the folding table shown in FIG. 1 in a folded position;
FIG. 3 is a side elevational view of the folding table shown in FIG. 1 in the use position;
FIG. 4 is a side elevational view of the folding table shown in FIG. 1 in the folded position;
FIG. 5 is a bottom plan view of the table top and a portion of the folding linkage for the folding table shown in FIG. 1;
FIG. 6 is a detail view of a portion of the linkage for the folding table shown in FIG. 1; and
FIG. 7 is a detail view of a portion of the frame and the slot for the folding table shown in FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings and in particular to FIGS. 1 and 2, there is shown a folding table, generally designated 10. The table 10 includes a folding tabletop 12 that folds from a use position wherein the tabletop 12 is horizontal as shown in FIGS. 1 and 3, to a folded storage position wherein the tabletop 12 is substantially vertical, as shown in FIGS. 2 and 4. The tabletop 12 typically mounts on a support frame 14 that rolls on casters 16. The casters 16 provide for easy portability. In a preferred embodiment, the casters 16 are lockable so that the table 10 can be secured at a position for use or storage. The frame 14 includes vertical upright structures 40 at opposite ends of the table. The upright structures 40 mount to an associated arcing lower frame member 42 having the casters 26 mounted thereon. The lower frame member 42 may be removably mounted to the uprights 40 for more compact shipping. Longitudinal frame members 44 extend lengthwise and connect the frame upright structures 40. It can be appreciated that the frame 14 is configured so that when the tabletop 12 is folded to a use position as shown in FIGS. 2 and 4, the lower frame members 42 slide beneath the cross members 44 and the tables 10 may be closely nested for storage with the generally vertical tabletops 12 arranged in parallel close to one another.
To facilitate folding, the table 10 includes a pair of linkages 20, one associated with each vertical frame structure 40. Each linkage 20 includes a first member 22 mounted to an underside of the tabletop 12, as shown most clearly in FIGS. 6 and 7. A longitudinal slot 24 is formed in element 22. The slot 24 has a substantially straight main portion, but includes an end portion 26 that extends upward from the main section of the slot 24 in a slightly upward arcing manner. The end portion 26 extends at an angle of approximately 25 degrees in a preferred embodiment. However, it has been found that satisfactory performance has also been achieved when the end portion 26 is at an angle of 20 degrees to 30 degrees from the main portion of the slot 24. A follower 32 mounts on a bracket 48 at the top of the vertical frame structure 40 and acts as a pivot for the tabletop 12. The follower 32 rests in the slot 24 and moves from the endmost point of the end portion 26 in the use position to the opposite end of the slot 24 in the storage position while the tabletop 12 pivots. The intersection of the main straight portion of the slot 24 with the end portion 26 forms a toggle point 28 that retains the follower 32 in the end portion. In the use position, the follower 32 is securely positioned at the extreme tip of the end portion 26.
The linkages 20 are configured so that the follower 32 cannot accidentally be moved from the use position due to the geometry of the slot 24. In order to actuate the linkage 20 and move the tabletop 12 from the use position to the storage position, it is necessary to lift the edge of the tabletop 12 opposite the end portion 26. The lifting moves the end portion of the slot 26 up and allows the follower 32 to move past the toggle point 28 along the lowered edge of the end portion 26. The tabletop 12 and the linkages 20 may then fold to the folded storage position as shown in FIGS. 2 and 4. It can be appreciated that bumping or sitting on any of the edges of the tabletop 12 does not accidentally fold the tabletop 12. The geometry of the slot end portion 26 prevents the follower 32 from being jarred or sliding beyond the toggle point 28 and prevents accidental folding.
Each of the linkages 20 also includes an arm 30 mounted to the first linkage element 22 at the underside of the tabletop and to an upright member 40. The arm 30 provides guidance and support to the tabletop 12 during folding while the tabletop 12 pivots and slides on the follower 32. As the linkage 20 is safe and reliable and prevents accidental folding, a tabletop 12 weighing more than conventional tops may be utilized. A heavier tabletop 12, having a granite, marble or another designer finish, may weigh more and lead to folding at a faster than desired speed. Therefore, a damper 34, such as a gas spring or gas springs, may be added to one or both of the linkages 20 to control folding between the storage position and the use position. The use of a tabletop 12 having a heavier designer finish provides an improved appearance that may eliminate the need for tablecloths. This speeds setup and take down and saves laundering costs. During folding, the weight of the tabletop 12 causes the tabletop to pivot and slide on the slot 24, thereby lowering to the folded position on its own, as shown in FIG. 2. A stop 36, shown in FIGS. 5 and 6, is engaged by the arm 30 and prevents the tabletop 12 from folding too far and causing damage or leading to the table 10 inadvertently tipping over. In the embodiment shown, the bushing 36 surrounds the follower 32 and provides a larger diameter and protects the follower 32 from damage.
Actuation of the table 10 between the folded and unfolded positions is simple and safe according to the present invention. From the unfolded position as shown in FIGS. 2 and 4, the lower edge of the tabletop 12 is simply lifted upward. The lifting and folding motion causes the follower 32 to move along the slot 24 past the toggle point 28. The lifting and folding motion also moves the arm 30 from a substantially vertical position toward an inclined position extending outward from the frame uprights 40. The gas spring or springs 34 move toward a horizontal position and retract as the tabletop 12 is folded. The follower 32 moves along the slot 24 and passes into the end portion 26 until reaching the extremity of the end portion 26 of the slot 24. At this position, the tabletop is horizontal and the table 10 is configured for usage. As pressure applied downward to any of the edges does not fold the table 10, a weight placed on the tabletop 12 does not pose any accidental folding danger. The tabletop 12 is supported on the frame uprights 40 and held by the arm 30 and the follower 32 engaging the end of the slot. Accidental bumping cannot move the follower 32 sufficiently far along the end portion of the slot 26 to pass the toggle point 28.
To fold the table 10, the edge of the tabletop 12 opposite the end portion 26 is lifted upward pivoting and sliding on the followers 32. The top 12 must be lifted and folded until the follower 32 passes the toggle point 28. This occurs when the tabletop is lifted approximately 4 degrees. The folding motion is assisted by the damper 34 and guidance is also provided by the arm 30. Once the follower 30 passes the toggle point 28, the tabletop 12 will fold to the use position under its own weight. The top continues to fold until the arm 30 engages the stop or bushing 36 as shown in FIGS. 2 and 4. It can be appreciated that the angle, arc and length of the end portion 26 is important so that the follower 32 cannot be moved inadvertently to the straight portion of the slot 24. It can be appreciated that the angle of the end portion 26 cannot be too great and offer too much resistance as an operator may accidentally tip the table 10 over while lifting. Conversely, the length of the end portion 26 must not be too short and the angle too flat or the follower 32 may pass too easily past the toggle point 28. Testing provided an optimal angle of approximately 25 degrees between the end portion 26 and the main portion of the slot 24. The present invention provides a table and folding linkage that provides for safe, simple and reliable folding of the tabletop between the use and storage positions not possible with prior folding tables.
It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
Patent Application
20080017082
