How does the tightening mechanism work on a hard hat.


How does the tightening mechanism work on a hard hat.

In: Engineering

I expect there are several different models of hard hat out there, so my explanation might not be of use to you, but with the ones I’m used to:

The head doesn’t rest directly against the hard outer shell of the helmet but rather a mesh or piece of cloth connected to a ring around the outer edge of the helmet which is in turn connected to the shell. This ring isn’t actually a closed loop but rather a strip of metal (or plastic) that is bent into one with the ends overlapping slightly. It is held in place by a knob that, upon turning, moves the overlapping ends further in one direction or the other, effectively changing the size of the circle. Think about it like adjusting a belt or wristwatch, only with a cogwheel instead of a pin and a hole.

Then there are also mechanisms to adjust the chin strap in various places, though they all operate on the same principle as most places where you adjust the length of a strap: The strap gets broken up into two parts, one of the parts gets directly connected to a piece of plastic and the other gets looped through said piece of plastic in a way that presses against itself to prevent accidentally moving. You can then adjust the length by pulling/ pushing the looped part by hand.