Need help figuring this out

I have this dumbwaiter pulley system, the smaller is where the cable for the dumbwaiter car goes over and then goes to the counterweight. When the small pulley is turned it rests on a threaded rod which causes it to press against the gear and ratchet that locks it up and prevents it from turning further. If you turn the big pulley (this would be where the loop of rope is attached that you pull to raise and lower the dumbwaiter) it unscrews the smaller pulley pulling it away from the ratchet wheel and allowing it to turn. The problem with this is this mechanism only locks up in one direction if I try turning the smaller pulley and the other direction the whole thing spins freely. The pulley would need to lock up in both directions either to hold everything stationary when the dumb- waiter wants to drift down when loaded or when the dumbwaiter car is empty and the heavier counterweight wants to pull it up. Here is a video I made  

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https://youtu.be/nYzFT2y67IQ?is=Jh3y-eyD90Vq\\\_Tgn

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I can't seem to find any patents from the energy elevator company addressing how the system is supposed to work the closest one I found was this but I don't know if it works the same.

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https://patents.google.com/patent/US950828A/en?q=(Dumbwaiter)&num=25&oq=Dumbwaiter&sort=old&page=7 I still can't figure out how it locks up when not utilizing the ratchet wheel.

HELP can't figure this out.