reference is made to the drawings for a description of the preferred embodiment of the present invention wherein like reference numbers represent like elements on corresponding views . the present invention is a gameboard activation / deactivation system . in the preferred embodiment , it relates specifically to a ping pong table but it can relate to any type of gameboard playing surface that needs to be level during play . the surface is deactivated to prevent unauthorized play by tilting it so that any attempt to play on the surface would be impossible . the gameboard playing surface 11 is provided with a mounting base 13 having a high side 15 and a lower side 17 in relation to said high side . the gameboard playing surface is hinged 19 to the high side of the mounting base , and in the preferred embodiment , the table surface is secured proximate along one edge thereof with a hinge connection 19 of any suitable type to the high side 15 of the base . since the width of the base is not equal to the full width of the ping pong table , the hinge connection is disposed inboard of the edge 21 of the table but parallel thereto . in a table or playing surface having a higher l / w ratio , the hinge can be mounted closer to the playing surface edge . a means is disposed in the base for raising and lowering the gameboard in response to activation and deactivation signals . this means is comprised of several elements . it includes at least one extendable cylinder 23 which engages the gameboard at a position opposite 25 to where the gameboard is hinged to the base . the cylinder ( s ) could be either a compressed gas cylinder ( one in which the normal condition is extended unless it is collapsed by force to the retracted position ) or it could be a compressed air or hydraulicly actuated cylinder which is cycled by the introduction of either compressed air or a fluid under pressure to extend the cylinder and collapsed by the release or outletting of either the compressed air or the fluid . in the preferred embodiment of the invention , a pair of compressed air cylinders 25 are provided disposed in spaced relation in the base along the length of the table to provide a more stable activation and support means for the game playing surface 11 . the pair of cylinders are secured proximate the opposite edge 27 of the table surface from the hinge connection with the base . the cylinders have a predetermined extension length whereby when they extend to the selected length , the game playing surface will be disposed level on the base . a means is provided for introducing compressed air into the cylinders upon receipt of an activation signal and for releasing compressed air from the cylinders upon receipt of a deactivation signal . in the preferred embodiment , an electric motor - driven air compressor ( not shown ) disposed inside the base is provided for generating the compressed air to extend the cylinders 25 . an electric solenoid actuated on - off switch for the compressor is activated to the &# 34 ; on &# 34 ; condition by an activation signal . in the preferred embodiment of the invention , the switch automatically switches to the &# 34 ; off &# 34 ; condition when a predetermined air pressure is reached in the cylinders after they have been fully extended . when the selected pressure is sensed by a sensor , it sends a signal to the solenoid which reverses the on - off switch to the &# 34 ; off &# 34 ; condition . a means is provided for releasing the compressed air from the cylinders upon receipt of a deactivation signal , and this is simply a solenoid controlled air release valve which is activated by an electronic deactivation signal to open the valve and allow the compressed air to escape from the compressed air cylinders . these elements are all commercially available items and are therefore not illustrated in the drawings . the means for raising and lowering the gameboard also includes a coin receiver , timer , and signal generator ( also commercially available items ) which operate in the following manner . as a coin is inserted into the coin receiver , an electronic signal is generated to activate the gameboard , and as a preselected time limit elapses without resetting of the timer by insertion of another coin into the coin receiver , a signal is generated to deactivate the gameboard . the gameboard can also be provided with an electronic scoreboard 29 which is activated by buttons secured to the edges of the table near the ends . the scoreboard could be utilized to generate the deactivation signal upon reaching a preselected score . an alternative embodiment of the invention could include compressed gas cylinders which have an electric driven jack screw whereby as the activation signal occurs the compressed gas cylinders would be allowed to expand to the preselected length raising the gameboard to the level position . upon receipt of a deactivation signal , a jack screw could be used to pull the gameboard down to the deactivated condition against the extension pressure of the gas cylinders . as a further alternative , jack screws alone could be used for raising and lowering the gameboard . it is also to be understood that the coin receiver need not literally receive legal tender but could receive substituted slugs or could be electronically activated by a control signal to indicate that authorized play can take place for predetermined lengths of time . other means for controlling the activation / deactivation signals are also within the scope of the invention but not relevant to the operation thereof . a protection means is provided to prevent foreign objects and players or small children &# 39 ; s anatomy from being trapped between the playing surface and the lower sides of the mounting base when the gameboard is deactivated . in its simplest form it is a collapsible skirt 31 secured around the lower side of the base and between the base and the playing surface . thus , it will be seen from the description of the preferred embodiment that all of the objects and advantages of the invention are achieved . while the preferred embodiment of the invention has been described in considerable detail herein , the invention is not to be limited to such details as have been set forth except as may been necessitated by the appended claims .
a gameboard activation / deactivation system which tilts the gameboard after a predeterined time to deactivate the board and raises it to level for play upon activation .