Without a brake, they are not suitable for lifting, only for pulling.

Looking at some patents and studying the puller a little more I guess I
have a clearer picture of how the "Weston brake system" operates.
Mines has a 4" diameter ratcheting pawl that is not keyed to the shaft.
Surrounding the pawl are two friction discs, this assembly is pressed
together by a cam system which is keyed to the shaft.

I was initially surprised that such a small surface area could control
6000# of weight, but when I thought about it some more I guess thats
about the same surface area on the front disc brake pads on a small
car.

It's a pretty neat mechanism.

Aloha, Russell