Abstract: A mechanical anti-theft device of the type applied to the steering wheel of an automotive vehicle which automatically ratchets to it's applied position without necessity of key lock actuation is provided with several security enhancing features which cumulatively prevent or make the device exceedingly difficult to unlock using conventional burglary tools or lock picking techniques. The features include configuring the ratchet teeth of the telescoping rod member in a way which minimizes any attempt to deactivate the lock unless the key is used. In combination with the ratchet teeth configuration, the lock pawl mechanism is configured to include an arcuate, transversely extending apex edge line or surface which cooperates with or is sized to be coincident with the rod members circumference to prevent a wedge, shim or pick from being readily easily inserted between pawl and ratchet tooth to force a retraction of the pawl.

Abstract: An electronic alarm is disclosed for use in a moving vehicle which generates ultrasonic sound for preventing animals from moving into the path of the vehicle. The device includes a simplified driver circuit for generating electrical impulses in the form of square waves having constant peak-to-peak voltages. The driver generates the square waves with periodic, sequentially increasing wave frequencies followed by sequentially decreasing wave frequencies. A coupling transformer converts the square waves into electrical sine wave voltages having high peak-to-peak voltages to cause a piezo-electric transducer to emit intense, ultrasonic sounds of periodically increasing frequencies followed by periodically decreasing frequencies simulating the warble effect of a siren without excessive heating and premature failure of the transducer. The ultrasonic warble effect confuses the animal to prevent inadvertent movement by the animal into the oncoming vehicle's path without injury to the animal.