INSULATED SCREWDRIVERS

Shannon News, 22 March 1929, Page 3

INSULATED SCREWDRIVERS

Many a valve has been burned out, oi battery seriously damaged, by an accidental short circuit of the high tension battery through the valve filament when making adjustments to the components of a receiver. One of the most common causes of :sm:h accidents is the use of metal tools inside a cabinet in such a way rhat the body of the tool can bridge wires carrying the.high tension current it' it touches them. Whenever possible, the high tension battery should be disconnected when making such adjustments, but in some cases it is'necessary to note the result of adjustments on the operation of the receiver as they p.re made. The removal of the high tension battery then becomes impossible.

In such cases the risk of damage can be eliminated by using a screwdriver which has been insulated in such a way that it cannot cause short circuits. There are two simple ways of doing this. The first is to take a length of black insulating tape, which is treated with a rubber compound to make it slightly sticky, and bind the metal shank of the screwdriver with it, leaving only the tip of the blade exposed. The rubber binding should then be dusted with powdered chalk to cover the tacky exposed surface of the tape.

A more effective and convenient inr sulation can bo provided by obtaining a piece of thin rubber tube about a 3 long as the blade, and slightly smaller in diameter, carefully drawing it over . the blade so that it forms a tight casing. This casing will last indefinitely, and can easily be replaced if the rub--ber shows any sign of perishing.