A casing with common padded first and second cavities holds two self-contained, battery-operated, commercial, digital-electronic pocket-calculators in a removable fashion. The "equal/repeat" keys of both calculators are brought out to calculator-embedded contacts by the manufacturer. The casing further includes a rocking rod, two micro switches, a battery and a control circuit. The control circuit develops "shorts" spaced by one second time intervals. The calculators are used as time-pre-programmed, decrementing, by seconds, time, scorekeepers as the shorting pulses are applied to the one calculator whose owner's move it is in a game of speed chess. The calculators and other parts are consumer-replaceable.

An assembly of spaced chess clocks, each present on support means flanking a chess board area, said clocks being operated by multiposition switches present on each of the flanking support means. Each flanking support means additionally has a circuit activating on-off switch, a move light to indicate that the opponent must execute a move, and a circuit activating indicator light. Each of the flanking support means may further be provided with a high intensity lamp separately operated by switch means. The multiposition switches are connected by a circuit which is responsive to like oriented switch positions where one clock is disconnected, the other clock is started, and a move light is energized to indicate that the player must execute a move whose clock has been started. Each clock is pivotally mounted to the support means so the clocks can assume a number of different viewing and non-viewing positions.

The invention relates to an electrical chess clock comprising a pair of time measuring circuits each having a digital time display device. The time measuring circuits are driven by a common pulse source which may alternately be connected to the time measuring circuits by means of a switching circuit being operated by the players. The digits of the time display device which normally indicates minutes may in certain periods of time, for example during the last minute of each hour, be shifted to indicate seconds. It is then sufficient that each time display device contains three digits.

A chess game in which the chess pieces of both colors are translucent and carry a lamp; battery, miniature radio receiver and switch responsive to the receiver which couples the lamp for energization by the battery in response to receipt of a control signal. The receivers of differently colored chess pieces are responsive to control signals of different frequencies. A control unit including a timing motor driven commutator alternately turns on a pair of radio transmitters of different frequencies for a predetermined time duration for alternately lighting the pieces of each color to indicate the time in which a move must be made.

A game apparatus including two sets of playing cards and a timing device. One of the sets of cards each includes indicia on one side thereof representative of an activity. The second set of playing cards each includes indicia which is identical to a portion of the indicia on one of the playing cards of the first set so that during the play of the game a card from the second set can be matched with a card from the first set by matching the identical indicia portions. The timing device includes an internal motor and governor which rotates a pointer on an elapsed time dial which times the period in which a player is attempting to make a matched pair of cards. The timer includes two manually actuatable levers which control the direction of rotation of the pointer. The pointer begins at a zero or reference position and rotates in one direction while the first player attempts to make a match. After a match is accomplished the player depresses one of the levers, causing the pointer to rotate in the opposite direction back toward the reference point and past the reference point if the opposing player requires a longer period of time to make a match. As soon as the opponent makes a match he then depresses the other lever causing the pointer to reverse again. This sequence is continued until all of the cards have been matched. Thereafter the timer is stopped by a master control button. The winner is determined to be the player who has used the least total time to make his matches. Since the timing device has automatically summed the differences between the players' time periods, the winner can be read directly from the dial as the one indicated to have used the least total time.