Table Leg System

None.

1. Field of the Invention

The present invention is for a folding table leg system, and more particularly pertains to a lever operated locking base for a folding table leg.

2. Description of the Prior Art

Practical table legs, such as for boats and other uses, have always been a problem. The legs have been unstable and awkward.

The present invention overcomes the problems of prior art table legs.

The general purpose of the present invention is a folding table leg system.

According to one embodiment of the present invention, there is provided a folding table leg system, including an extruded rotatable block member having an uplock groove and a downlock groove and a latch member pivotally secured between opposing support brackets. Spring members secured to the latch member bias the latch member for engagement with either a downlock or an uplock groove in the extruded rotatable block member. Actuating levers are secured to the latch member to overcome spring biased engagement of the latch member with the rotatable block member to allow rotation of the rotatable block member and an attached leg member to position the leg between a down and locked position and an up and locked position.

One significant aspect and feature of the present invention is a folding table leg system in which a table leg can be positively locked in an extended or a stowed position. A latch member is held in engagement with an uplock or downlock groove in an extruded rotatable block member by spring force.

Another significant aspect and feature of the present invention is the utilization of actuation levers to simultaneously overcome spring force engagement and to operate a latch member. A latch member pawl having a wedge shape engages either an uplock or a downlock groove in a rotatable block member. The latch member pawl has opposing grooves along its tip which act as a secondary safety catch in conjunction with arced lip members of a downlock groove.

A further significant aspect and feature of the present invention is a folding table leg system which stows in a minimum profile position.

Having thus described embodiments of the present invention, it is the principal object of the present invention to provide a folding table leg system which can lock a leg in both the down and the up position.

Other objects of the present invention and many of the attendant advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, in which like reference numerals designate like parts throughout the figures thereof and wherein:

FIG. 1 illustrates an isometric view of a folding table leg system;

FIG. 2 illustrates an exploded isometric view of a locking base;

FIG. 3 illustrates a top view of the locking base;

FIG. 4 illustrates a right end view of the locking base;

FIG. 5 illustrates an inverted cross sectional view along line 5--5 of FIG. 3 of the locking base with a main support tube in the down and locked position;

FIG. 6 illustrates the locking base of FIG. 5 and the disengagement of the pawl from the rotatable block member;

FIG. 7 illustrates the locking base of FIG. 5 with the main support tube in the up and locked position;

FIG. 8 illustrates the engagement of the pawl with the downlock groove;

FIG. 9, an alternative embodiment, illustrates the engagement of the pawl with the downlock groove where hook and latch safety catches are utilized;

FIG. 10 illustrates table legs secured in the up and locked and in the down and locked positions on a table surface; and,

FIG. 11 illustrates a comparative example of the use of the present invention to provide for space saving and use in short length tables.

FIG. 1 illustrates an isometric view of a folding table leg system 10, the present invention, including a main support tube 12, a horizontal support tube 14 aligned and secured to the main support tube 12 at a right angle, and a locking base 15. The horizontal support tube 14 includes skids 16 and 18 of metal, rubber or plastic located at the ends of the horizontal support tube 14, and an access hole 20 in alignment with the longitudinal axis of the main support tube 12. The main support tube 12 and the horizontal support tube 14 form a table leg 17 which secures to and rotates about the locking base 15.

The locking base 15 includes an extruded rotatable block member 24 and a latch member 26 each pivotally supported between left and right angled mirror image-like support brackets 28 and 30. Angled actuating levers 32 and 34, having pliable plastic end caps 36 and 38, secure to the latch member 26. The latch member 26 is spring loaded to engage either an uplock or a downlock groove in the extruded rotatable block member 24, as later described in detail.

FIG. 2 illustrates an isometric exploded view of the locking base 15 where all numerals correspond to those elements previously described. The one-piece support bracket 28 includes vertical planar members 40 and 42, an interceding horizontal planar member 44 aligned between the vertical planar members 40 and 42, and a vertical planar member 46 extending vertically from the horizontal planar member 44. The vertical planar member 46 includes an upper reinforced thicker area 48 having a horizontally aligned pivot hole 50. A plurality of recessed anchoring holes 52a-52n along the horizontal planar member 44 allow for the mounting of the support bracket 28 to the undersurface of a table by the use of appropriate fasteners.

In a like manner, the one-piece support bracket 30 is constructed in a similar fashion to include vertical planar members 54 and 56, an interceding horizontal planar member 58 aligned between the vertical planar members 54 and 56, and a vertical planar member 60 extending vertically from the horizontal planar member 58. The vertical planar member 60 includes an upper reinforced thicker area 62 having a horizontally aligned pivot hole 64. A plurality of recessed anchoring holes 66a-66n along the horizontal planar member 58 allow for the mounting of the support bracket 30 to the underside of a table by the use of appropriate fasteners.

The rotatable block member 24 includes a substantially rectangular solid-like block member 68 having an interrupted arcuate member 70 descending from one edge of the substantially rectangular solid-like block member 68 to terminate in a smaller radiused end member 72. The arcuate member 70 includes an arcuate surface 74 interrupted near its top by a horizontally aligned downlock groove 78. The arcuate surface 74 is also interrupted near the smaller radiused end member 72 by a horizontally aligned uplock groove 76. Dowel pin pivots 80 and 82, being the centers for the arcuate surface 74 and for rotation of the rotatable block member 24, extend outwardly and horizontally from the sides 68a and 68b of the block member 68 to accommodate washers 84 and 86 and horizontally aligned pivot holes 50 and 64 in the upper reinforced thicker areas 48 and 62 of the support brackets 28 and 30, respectively. A threaded hole 88 and an annular groove 90 align through the planar surface 68c in the block member 68 to mountingly accommodate and serve as a securement base for the threaded rod 92 and for the tubular edge 94 of the main support tube 12, respectively. A nut 96, illustrated in FIG. 1, gains access to the interior of the horizontal support tube 14 and the main support tube 12. A finger and hand grasping surface and area 69 of a predetermined geometrical configuration provides for rotational movement of the system.

The latch member 26 is extruded as a one-piece member which resembles the mating of two planar members, one of which includes a pawl. One such planar member 98 includes a pawl 100 extending at an angle from the planar member 98 to automatically engage either the downlock groove 78, as illustrated, or to engage the uplock groove 76 subsequent to rotational movement of the rotatable block member 24. The other planar member 102 serves as a mount for spring members 104 and 106 and actuating levers 32 and 34 which are secured by a plurality of fasteners 108a-108n passing through the spring members 104 and 106 and actuating levers 32 and 34 to secure to the planar member 102. Dowel pin pivots 110 and 112, as also illustrated in FIG. 3, extend from the thick area 114 formed by the planar members 98 and 102 to fit and align within spacer washers 116 and 118 and holes 120 and 122 in the vertical planar members 42 and 54 of the support brackets 28 and 30, respectively.

Horizontally aligned pins 124 and 126, having fluted engagement surfaces, extend between and frictionally engage the support brackets 28 and 30 to capture the rotatable block member 24 and the latch member 26 and their associated members. With additional reference to FIG. 3, the ends of pin 124 are aligned in holes 128 and 130 in vertical planar members 40 and 56, and the fluted engagement surfaces 132 and 134 at the intermediate areas of the pin 124 frictionally engage holes 136 and 138 in vertical planar members 42 and 54. In a similar fashion, the ends of pin 126 are aligned in holes 140 and 142 in the opposing ends of vertical planar members 40 and 56, and the fluted engagement surfaces 144 and 146 at the intermediate areas of pin 126 frictionally engage holes 148 and 150 in the vertical planar members 42 and 54. Pin 124, in addition to serving as a structural tie member, also serves as a spring tension facilitator. Spring members 104 and 106 extend from the latch member 26 to a position beneath the pin 124 in a manner to cause upward rotational positioning of the pawl 100, as viewed in FIG. 2, about dowel pin pivots 110 and 112 into the downlock groove 78, or alternately of the pawl 100 into the uplock groove 76. Actuating levers 32 and 34 are angled upwardly, as viewed, to clear pin 124 and to allow the user finger insertion room between the ends of the actuating levers 32 and 34 and the lower table surface so that actuation may be accomplished. A protective rubber member 22 secures to one edge of the rotatable block member 24 for stacking of tables when the horizontal support tube 14 is in the up and locked position.

FIG. 3 illustrates a top view of the locking base 15 where all numerals correspond to those elements previously described. Illustrated in particular are the horizontal pins 124 and 126 in frictional engagement with the support brackets 28 and 30 to cause capture of the rotatable block member 24 and latch member 26 therebetween.

FIG. 4 illustrates a right end view of the locking base 15 where all numerals correspond to those elements previously described.

FIGS. 5, 6 and 7 best illustrate the mode of operation of the locking base 15.

FIG. 5 illustrates an inverted cross sectional view of the locking base 15 with the main support tube 12 in the down and locked position along line 5--5 of FIG. 3, where all numerals correspond to those elements previously described. The locking base 15 secures by fasteners 152a-152n through support brackets 28 and 30 to a planar table member 154. Pawl 100, having angled sides, is illustrated in wedge-like engagement with the downlock groove 78 in the rotatable block member 24 to maintain the rotatable block member 24, and thus the horizontal support tube 14 and the main support tube 12, in the down and locked position, as illustrated. The angled sides of the pawl 100 are driven by force of spring members 104 and 106 into wedge-like contact with two opposing surfaces of the downlock groove 78, as illustrated in detail in FIG. 8.

FIG. 6 illustrates the locking base 15 of FIG. 5 with the actuating lever 32 depressed to disengage the pawl 100 from the downlock groove 78 of the rotatable block member 24 so that the rotatable block member 24, main support tube 12, and attached horizontal support tube 14 can be pivoted about the dowel pin pivots 82 and 80. The actuated position of actuating lever 32 is illustrated in dashed lines and referenced as 32a. Actuation of either actuating lever 32 or actuating lever 34 causes the latch member 26 to rotate about the dowel pin pivots 112 and 110, thereby removing the pawl 100 from influence of the downlock groove 78. Upon release of the rotatable block member 24 from the latch member pawl 100, the main support tube 12 and the horizontal support tube 14, which form table leg 17, are swung as indicated by arrow 156 toward a position parallel to the planar table member 154 to automatically engage the uplock groove 76 at the opposing end of the arcuate surface 74. Spring pressure provided by spring members 104 and 106 causes the pawl 100 to slidingly traverse the arcuate surface 74 until spring forced engagement of the pawl 100 with the uplock groove 76 is effected, as illustrated in FIG. 7.

FIG. 7 illustrates the locking base 15 of FIG. 5 having the rotatable block member 24 in the up and locked position where all numerals correspond to those elements previously described. As previously described, actuating levers 32 and 34 were previously depressed allowing disengagement of the pawl 100 from the downlock groove 78 to allow positioning of the table leg 17 parallel to the planar table member 154, as illustrated. Spring members 104 and 106 forcibly position the pawl 100 into wedge-like forced engagement with the uplock groove 76 to lock the table leg 17 in the folded and stowed position. The folded and stowed position of the table leg 17 provides for leg stowage in very close proximity to the undersurface of the table. This close-in leg stowage offers a very low profile which is highly desirable when stacking of tables incorporating the folding table leg system. Placement of the dowel pin pivots 80 and 82 at a distance from rather than closer to the table underside is of great significance with respect to obtaining a low profile leg stowage. If, for instance, a pivot point were placed at a point closer to the table undersurface or closer to the table center, stowage with a greater profile would be the likely outcome.

FIG. 8 illustrates the engagement of the pawl 100 of the latch member 26 with the downlock groove 78 of the rotatable block member 24, where all numerals correspond to those elements previously described. The pawl 100 includes surfaces 158 and 160 which are angularly displaced approximately the same amount from the pawl center line 162 to form a wedge. The tension of the spring members 104 and 106 forces the tapered and angled surfaces 158 and 160 of the pawl 100 into wedge-like engagement with horizontally extending arced lips 164 and 166. Constant force wedge-like engagement of the pawl 100 into the downlock groove 78 provides for secured rigidity of the table leg 17, without looseness or sloppiness, with respect to the planar table member 154 illustrated in FIG. 10. Arced lip 166 is located at the junction of the arcuate surface 74 and the downlock groove 78. The other arced lip 164 is located in opposition to the arced lip 166 on the planar surface 168 of the downlock groove 78. Component wear is accounted for in the design of the pawl 100 and the downlock groove 78 and adjacent areas. Should wear occur where the arced lips 164 and 166 contact the angled pawl surfaces 158 and 160, spring tension is available to drive the wedge-like pawl 100 deeper into the downlock groove 78 to ensure plumb and well secured alignment of the main support tube 12.

Arced lips 164 and 166 also provide a secondary locking function in that if excess side loads are introduced to the table leg 17, horizontally aligned groove 170 or 172 at the lower portions of pawl surfaces 158 and 160 will catch and engage arced lip 164 or 166, respectively, if the pawl 100 is forced upwardly and outwardly from the downlock groove 78 by displacement of the table leg 17 and corresponding displacement of the rotatable block member 24. This engagement prevents collapse of the table leg 17, thereby holding the table leg 17 upright in an uncollapsed position with only a slight deviation from plumb vertical alignment.

FIG. 9, an alternative embodiment, illustrates the engagement of a pawl 100 of the latch member 26 with the downlock groove 78 of the rotatable block member 24 where all numerals correspond to those elements previously described. In this illustration, hook and latch members have been incorporated in lieu of arced lips 164 and 166 and grooves 170 and 172 to effect a positive locking method should leg side loads occur. As in FIG. 8, the pawl 100 includes surfaces 158 and 160 which are angularly displaced the same amount from the pawl center line 162 to form a wedge. The tension of the spring members 104 and 106 forces the tapered and angled surfaces 158 and 160 of the pawl 100 into wedge-like engagement with horizontally extending and protruding semi-circular profile hook members 180 and 182 which resemble a half portion of the arced lips 164 and 166 of FIG. 8. The semi-circular hook member 180 is located at the junction of the arcuate surface 74 and the downlock groove 78. The other semi-circular hook member 182 is located in opposition to the semi-circular hook member 180 on the planar surface 168 of the downlock groove 78. Component wear is accounted for in the design of the pawl 100 and the downlock groove 78 and adjacent areas. Should wear occur where the semi-circular hook members 182 and 180, respectively, contact the angled surfaces 158 and 160, spring tension is available to drive the wedge-like pawl 100 deeper into the downlock groove 78 to ensure plumb and well secured alignment of the main support tube 12. Semi-circular hook members 180 and 182 also provide a positive secondary locking function in that if excessive side loads are introduced to the table leg 17, horizontally aligned semi-circular latch members 184 and 186 at the lower portions of pawl surface 160 or 158 will catch and engage the semi-circular hook member 180 or 182, respectively, if the pawl 100 is forced upwardly and outwardly from the downlock groove 78 by displacement of the table leg 17 and corresponding displacement of the rotatable block member 24. This positive hook- and latch-like engagement prevents collapse of the table leg 17, thereby holding the table leg 17 upright in an uncollapsed position with only a slight deviation from plumb vertical alignment.

FIG. 10 illustrates a table leg 17 secured to the lower planar surface of planar table member 154 of a table top 174 and erected and locked into an extended position by the locking base 15. Also illustrated is a table leg 17 folded over into a stowed position parallel to the lower planar surface of planar table member 154 and locked into the parallel position by the locking base 15.

FIG. 11 illustrates an example of the use of the present invention with a table of minimum length as compared to other style or generic leg pivot or locking devices. The location of the pivot point 81 created by the dowel pin pivots 80 (and 82) away from the bottom surface of the table top is of great importance when incorporating the folding table leg system 10. The locking base 15 is positioned to locate the table leg 17 at a fixed distance D from the edge of the table top 174 as is a generic table leg 188 and a generic hinge 190 having a pivot 192 on a generic table top 194. Each table leg 17 and 188 provides for a common and equal height H between the lower table surface and the lower part of each table leg which sets on the floor. It can be seen that the length of table leg 17, incorporated in the present invention, is shorter than the length of generic table leg 188. For sake of discussion, assume that the pivot point 81 is 2 inches from the table undersurface and the length of the table leg 17 is 24 inches, thus providing support for the bottom of the table top 174 at 26 inches above the floor. Assume that pivot point 192 of the generic table leg 194 is flush with the lower surface of the generic table top 194--both table legs 17 and 188 are then pivoted about their respective pivot points 81 and 192 toward the center of their respective table top lower surfaces. Table leg 17 swings about a 24-inch radius arc and meets the table tangent to reference line 200, while table leg 188 swings about a 26-inch radius arc to pass through the reference line 200. This distance, shown as extra distance E, is the required distance used by one generic table leg. Of course, the extra room required for two generic table legs would be twice the designated extra distance E or 2 X E. Thus, it can be seen that the folding table leg system 10, the present invention, can be utilized for use in short length tables by virtue of the ability to require less space when folded for storage. Minimum distance between two extended table legs is achieved by utilization of the present invention.

Various modifications can be made to the present invention without departing from the apparent scope hereof.