Abstract: A transmission brake disengagement apparatus for mounting on a drag racing car having a transmission brake safety switch and an infrared radiation actuated starting switch for providing an electrical signal to effect the disengagement of an electrically actuated transmission brake of a drag race car.

Abstract: A circuit for decreasing the engine speed of a drag racer for a selected interval during a race has a programmable first down counter for setting the time the interval begins, a programmable second down counter for setting the duration of the interval and a clock connected to both counters.

Abstract: A circuit for disengaging an electrically actuated transmission brake of a racing car has a bank of transistors in series with the brake to hold the brake on at the beginning of a race. The bases of the transistors are connected through normally open contacts of a relay to the emitter of a transistor that can be turned on or off by an optoisolator and the brake is connected through diodes to the relay coil to isolate the transistor bases once the brake has been disengaged. The optoisolator is connected, through diodes, to the zero count terminals of two clocked, programmable counters either of which will turn the optoisolator off at the end of a count. Reset terminals of both counters are connected to the outputs of a flip-flop to disable one counter and toggling of the flip-flop is effected by closing normally open contacts of a second relay to complete a circuit between the flip-flop input and a voltage regulator output through a Schmitt trigger.

Abstract: Apparatus for measuring length of an elongate cable. A frame having a hole therethrough includes a pair of rollers mounted for rotation thereon. The circumferences of the rollers are rollingly engaged with one another over the hole and a cable which is to be measured is held between the rollers and passed downwardly through the hole thereby rotating the rollers. A magnet is mounted on one of the rollers adjacent the circumference thereof. Mounted on the frame adjacent the circumference of the roller having the magnet mounted thereon is a magnetically-activated switch which closes each time the magnet passes thereby. The switch provides an input to a transmitter which generates a signal including pulses indicative of the number of rotations of the wheel having the magnet mounted thereon.

Abstract: Apparatus for controlling a brake on a drawworks having cable wound thereon. A tension gauge detects the tension in the cable which is displayed on a switch gauge. A pulse generator provides periodic pulses to one side of a relay having a set of normally open contacts. When the tension is at or above a preselected level, the other side of the relay is grounded. The relay contacts pulse a pneumatic relay which is connected to a ram that operates the drawworks brakes. When tension is at or below a preselected level, a second pneumatic relay is actuated for maintaining the ram in a brake activating condition. A switch is connected to a third pneumatic relay, which in turn is connected to the ram to permit manual brake activation and deactivation.