In 1933, Phillips obtained the rights to a socket screw invented by John Thompson that had a cross-slotted rather than slit head. To turn the screw, one had to use a tool that resembled an arrow ...

it’s almost impossible to get that screw out with a common Phillips-head or flat-blade (slotted) screwdriver. Even worse, the odds of removing the screw decrease each time the screwdriver slips ...