There mightn’t be any reason to connect the hat known as the cloche with the bell for which it’s named, given the resemblance of their shapes. The similarity may end there. Unless you want to make a silly cheap pun and say that the hat kind of rings a bell for some reason.
More productive, probably, to just work on drawing curves by sketching a figure wearing a cloche and simply exaggerating the resemblance a little bit more by simplifying the shapes to an extreme. Whether it’s quite characteristic of my style of drawing or not, it might be that I tend to like drawing curvy forms just because the arm and hand action that creates them is comfortable and pleasing to me when I draw.
The long and the short of it is that practice may make me better at drawing, but it also makes me happy as an activity in itself and for its own sake, and drawing curved forms feels pleasant and encourages me to draw more. And that, if I’m in the mood to draw curved forms, why then, drawing a cloche hat is a handy way to get into the process.
Shallow, I know. What do you expect from a person who makes cheesy puns in public and draws in a particular style merely because it feels nice!