Patent Publication Number: US-7220185-B2

Title: Height-adjustable game table

Description:
FIELD OF THE INVENTION 
   This invention relates to a game table. More particularly, this invention relates to a game table having an adjustable base structure for allowing adjustment of the height of the table&#39;s top. Specifically, in its preferred embodiment, this invention relates to an air hockey table with a playing surface on the tabletop that can be quickly and effortlessly adjusted by the players. 
   BACKGROUND AND OBJECTS OF THE INVENTION 
   Many recreational games are played upon a tabletop. Many tables are specifically designed to serve as a playing surface for a particular game, which game is played upon the table&#39;s top. Typical of these tables and games are pool tables for playing pool, ping-pong tables for playing ping pong, craps tables for playing craps, and air hockey tables for playing air hockey. Many of these table surfaces are large, bulky and heavy. 
   In such games as are played on these tables, it is generally optimal that the playing surface be located at a height that is comfortable for the players. Each table is designed so that the tabletop&#39;s height is set to best suit players of average height, but this tabletop height may be awkward for players of above or below average height. 
   U.S. Pat. No. 3,988,021 discloses a game table of the prior art that is provided with a pair of articulate leg structures and means for adjusting the height of the tabletop. The disclosed means includes a ratcheting mechanism that the player can use to adjust the table&#39;s height. The mechanism is cumbersome and burdensome, and requires an inordinate amount of time and effort by the user. If a player realizes during initial play that the height of the table is not optimal for his height, the player must interrupt the game, leave his playing position, and crawl dangerously underneath the heavy tabletop to actuate the ratcheting mechanism and lift the heavy top against gravity into a position that he cannot see until he returns to his playing position at tableside. It can be appreciated that it might take several attempts for the player to find a position that is optimal. It would be impractical to expect players to use this arrangement to modify the table&#39;s height for only a single or a few games of play. 
   It is therefore desirable and an object of the present invention to provide a game table adapted to allow players an alternative mechanism to adjust the tabletop to a height that is optimized to the players&#39; heights. 
   Due to the size and weight of tabletops in general, it is an additional object to provide such a game table that allows such adjustment quickly and effortlessly. 
   It is a further object to provide such a table in which the height adjustment mechanism is so quick and effortless to operate that players may conveniently optimize the tabletop&#39;s height for even a single game of play. 
   It is still a further object to provide such a table that allows a single player to adjust the table height from a position that approximates his playing position so that he can instantly evaluate the new height without trial and error. 
   Further, it is an additional object to provide such a table in which the height adjustment mechanism maintains the levelness of the tabletop. 
   The above and other objects are addressed by the following embodiments of the present invention. 
   SUMMARY OF THE INVENTION 
   The present invention is a game table having an instant and effortless adjustment mechanism for allowing users of various heights to raise and lower the tabletop to an optimal height for their game playing. The game tables and adjustment mechanisms of the present invention represent a significant advance in the state of the art by allowing the game players, while remaining in their playing positions, to adjust the tabletop to an optimal height, and to do so while maintaining the tabletop&#39;s levelness. The game tables and adjustment mechanisms of the present invention further advance the art by providing a height adjustment mechanism that is so fast and easy as to inspire players to adjust the tabletop to an optimal height before or even during each game of play. 
   The present invention is disclosed in two equally preferred embodiments. In a first embodiment, a pair of telescoping towers supports the top of an air hockey table. The towers serve as legs for the table and allow the top to be raised and lowered while remaining horizontal. Pressurized air pistons in each of the towers extend between and exert a force between the floor and the tabletop to counter-balance the weight of the tabletop and allow it to be freely lifted and lowered while seeming to be virtually weight-free to the player. Pedal-operated lock and release mechanisms are positioned at the bases of the towers facing the ends of the table where the players would normally stand during play. These pedals allow the players to release the normally locked mechanisms and lift or lower the table with the touch of a finger, and to lock the table into the most desirable of a number of discrete heights, all while standing in their normal playing positions at the ends of the table. Such a mechanism could easily be adapted to any game-playing table regardless of the weight of the tabletop, such as pool table, simply by employing an appropriately strong air piston. 
   In a second embodiment, two diverging pairs of legs are positioned under the top of an air hockey table. A pressurized air piston extends between and exerts a force between one of the pairs of legs and the tabletop to counter-balance the weight of the tabletop and allow it to be freely lifted and lowered while seeming virtually weight-free. The leg pairs are connected by gearing so that, as the top is raised and lowered, the angle between the table top and each pair of legs changes equally to maintain the tabletop&#39;s horizontal disposition. A hand-operated lock and release mechanism is positioned at the underside of the tabletop at an end where a player would normally stand during play. This allows a player to release the normally locked mechanism and lift or lower the table with the touch of a finger, and to lock the table at any one of an infinite number of heights, all while standing in a normal playing position at an end of the table. Such a mechanism could also be easily adapted to many game playing tables. 
   A complete appreciation for the various features and advantages of the present invention will be had by those skilled in the appropriate arts upon review of the following complete description of these two most preferred embodiments. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of an air hockey table in accordance with a first preferred embodiment of the invention showing a player (in phantom lines) in a typical playing position and actuating the pedal-operated lock and release mechanism; 
       FIG. 2A  is a cutaway view of a tower of the table of  FIG. 1  with the lock and release mechanism in its normally locked position and the tower adjusted for the highest tabletop position; 
       FIG. 2B  is a cutaway view of the tower of  FIG. 2A  with the lock and release mechanism pushed into its unlocked position; 
       FIG. 2C  is a cutaway view of the tower of  FIGS. 2A and 2B  with the lock and release mechanism returned to its normally locked position and the tower adjusted for the lowest tabletop position; 
       FIG. 3  is a cross-sectional view through the tower of  FIGS. 2A–2C  with the lock and release mechanism shown in its normally locked position and the tower adjusted for the highest tabletop position and the mechanism shown in phantom pushed into its unlocked position; 
       FIG. 4  is a side view of an air hockey table according to a second preferred embodiment of the invention with the tabletop shown in its highest position and shown in phantom in its lowest position; 
       FIG. 5  is a top perspective view of the table of  FIG. 4  with the tabletop exploded from the base assembly; 
       FIG. 6A  is an exploded view from below of the table of  FIG. 4 ; 
       FIG. 6B  is a close-up view of a typical rolling foot of the table of  FIG. 4 ; and 
       FIG. 6C  is a close up exploded view of the hand-operated actuator of the lock and release mechanism of the table of  FIG. 4 . 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION 
   Referring now to the drawings,  FIG. 1  through  FIG. 3  depict an air hockey table  100  having a tabletop  102  which is adapted with a horizontally disposed playing surface  104 . The perimeter of the tabletop includes a retaining wall  106  to keep the game puck (not shown) on the playing surface. A player  108  normally stands at each end  110  of the table as shown in phantom in  FIG. 1 . 
   The tabletop  102  is supported by two towers  114 . Each tower is comprised of a stationary lower inner tower member  118 , which remains on the floor  120  and a vertically movable upper outer tower member  124 , which is rigidly connected to the tabletop  102 . The lower inner tower members  118  fit loosely within the upper outer tower members  124  to allow the upper tower members to be raised and lowered relative to the lower members with no substantial tilting or twisting. 
   Rigid U-shaped pedal support  126  is pivotally connected to and disposed within the lower inner tower member  118 . Support  126  includes pedal  128 , pivot bar  130 , and locking elements  134 . The pedal support is free to swing about the pivot bar, which is pivotally connected to tower member  118 . The pedal support is biased by extension spring  136  into the “locked” position shown in  FIGS. 2A and 2C , wherein locking elements  134  protrude through openings  138  in the upper outer tower member  124  to deny the raising and lowering of member  124  relative to member  118 . 
   When pedals  128  of both towers  114  are pushed inwardly by each player&#39;s foot  140  into the “released” position of  FIG. 2B , locking elements  134  are moved out of openings  138  and tower member  124 , and therefore the tabletop  102  to which tower  124  is rigidly attached, is free to be raised and lowered. 
   It is anticipated that numerous alternatives to the locking elements shown may be substituted within the scope of the invention; for instance, such locking elements may take the form of magnets, which are brought against the upper outer tower member during the “locked” position. Or the locking elements may be in the form of cylindrical pins protruding from the U-shaped pedal support into round holes in the upper outer tower member. In whatever form, the locking elements need simply to create interference that denies relative vertical movement between the upper and lower tower members in order that they serve their intended purpose within the scope of the invention. 
   Further, it is anticipated that the U-shaped pedal support with its locking elements and pedal could be disposed within the upper outer tower member and could move up and down with that upper outer tower member. Provided that the locking action denies relative vertical movement between the upper and lower tower members and therefore to the tabletop, the essence of this feature of the invention is realized. 
   Air piston  144  is pre-pressurized and therefore adapted to exert an upwardly and downwardly extending force between the lower inner tower member  118  and upper outer tower member  124 . This force offsets the weight of the tabletop  102  to minimize the effort required to raise and lower the tabletop. Alternatively, a compression spring or some similar counter-balancing means may be used in place of the air piston to offset the weight of the tabletop. 
   As can be seen in  FIG. 1 , player  108  may easily push pedal  128  into the “released” position of  FIG. 2B  without moving substantially from his typical playing position. Having done so, both players can raise the tabletop  102  with the assistance of the lifting force of piston  144  to counter-balance the tabletop&#39;s weight, or can lower the tabletop with the assistance of gravity to offset the piston&#39;s force, all while remaining in their normal playing positions. By simply removing the foot  140  from pedal  128 , as the tabletop nears the desired vertical position, the tabletop will become locked into that position. This allows the players to remain in their normal playing positions and thereby more conveniently select a tabletop height that is most optimal for playing. 
   Because the array of openings  138  are at the same vertical locations on both upper outer tower members, the tabletop is automatically leveled into a horizontal position after repositioning. 
   Turning now to  FIGS. 4 through 6C , another air hockey table  200  is shown according to a second preferred embodiment of the invention. Tabletop  202  rests on a support structure  204  that comprises frame  206  and two pairs of support legs; free leg pair  208  and locking leg pair  210 . Leg pairs  208  and  210  are pivotable relative to frame  206  to effectively raise and lower frame  206 , and therefore raise and lower tabletop  202  from floor  120 . Leg pairs  208  and  210  are connected to each other by gearing  212  to ensure that their angular relationships to frame  206  are always equal, thereby ensuring that the tabletop  202  remains in a substantially horizontal disposition as it is raised and lowered. 
   Air piston  244  is pre-pressurized and therefore adapted to exert an upwardly and downwardly extending force between the tabletop  202  and the locking leg pair  210  at cross member  214 . This force offsets the weight of the tabletop  202  to minimize the effort required to raise and lower the tabletop. Valve  220  locks piston  244  in its present state of extension when the valve is in its “locked” position and releases the piston to be free to extend under its own pressure or to be compressed when the valve is in its “released” position. 
   When valve actuator  228  is pushed downwardly by a player&#39;s hand (not shown), valve  220  is caused into its “released” position, and the player can raise the tabletop  202  with the assistance of the lifting force of piston  244  to counter-balance the tabletop&#39;s weight, or can lower the tabletop with the assistance of gravity to offset the piston&#39;s force, all while remaining in his typical playing position. By simply removing his hand from actuator  228 , as the tabletop reaches the desired vertical position, the tabletop will become locked into that position. This allows the user to remain in a normal playing position and thereby more simply select a position that is most optimal for playing. 
   As the tabletop  202  is lifted and lowered and the angular relationship of leg pairs  208  and  210  to frame  206  is changed, the lower portions  230  of each leg are accordingly forced closer together or farther apart. Rollers  232  at the bottom ends of each leg allow the legs to roll smoothly on the floor as the relationship of the legs changes. 
   In an alternative embodiment (not shown) of the above-described table, the free leg pair is replaced by a second locking leg pair, including a second valve and air piston. In such an embodiment, two players standing at opposite ends of the table, both in their usual playing positions, simultaneously actuate the valves at their ends and cooperate to lift or lower the tabletop together. Such an embodiment is, of course, within the scope of the present invention. 
   It is also anticipated that there could be various arrangements for the two pairs of support legs of the second preferred embodiment while remaining within the scope of the invention. For instance, the legs pairs might be adapted to fold during the “released” position of the valve to effectively increases or reduce their heights. In such arrangement, the air piston may be disposed between the folding points of the leg pairs or may remind as disclosed above, between the locking leg pair and the tabletop. 
   Or the leg pairs may be disposed in a criss-crossing configuration, pivotally connected near to their mid-points and adapted at their top ends for horizontal movement relative to the tabletop as the angle between the leg pairs is adjusted to cause the vertical movement of the tabletop. 
   As can be appreciated, the present invention may take many forms without departing from its intended scope, that being a tabletop lifting and lowering mechanism that 1) counterbalances the weight of the tabletop, making lifting and lowering less laborious, 2) maintains the levelness of the tabletop despite its vertical repositioning, 3) allows one or more players to remain in their playing positions during the raising and lowering process, and 4) thereby makes practical and convenient the proper height re-adjustment of the game surface prior to every game of play. 
   Further, the present invention is sturdy, simple and can be easily fabricated. And the invention can be used in connection with game tables of various types. 
   It should therefore be understood that the scope of the invention should only be limited by the following claims.