Elextrolux floor brush.
No! There's a problem here, but most likely it's a quick fix.
The coupling that holds it to the wand or hose handle should turn completely, and there should be no squeek, or click!
Take a screwdriver, and remove the bottom brush assembly, there's a rubber gasget, I think that's the problem. It's most likely worn out, and pressing on the coupling. There might also be dirt in there, take it apart and have a look. You should also give it a squirt of WD-40 before you reassemble it.
This tool was first introduced with the model XXX in 1937 and was in production till the introduction of the model E which was about 1955, so no doubt it's gotten a lot of use.
Take it apart, see what you find, and let me know.
Alex Taber.