How do I release a block & tackle?

[Fuddy1952]

This should be simple, but I can't figure it out. My Dad had some block and tackles, all made similar to these two.
I have a great use for one now, hoisting something about 150# up for storage.
They all have a locking mechanism (a cam lock I'd call it) and I get it to hoist and mechanism holds the rope...but how do you release it???
Last picture I'm pointing in direction I was thinking you pulled it, but that just makes it lock tighter on the long pull rope!
I tried other way, still nothing.
Anyone familiar, thanks in advance!

 

[oosik]

Looks very similar to the one I have. Grab the the "pull rope" and walk away from the load. Give the pull rope a jerk - that should free up the locking mechanism.

 

[Fuddy1952]

Looks very similar to the one I have. Grab the the "pull rope" and walk away from the load. Give the pull rope a jerk - that should free up the locking mechanism.

Thanks. It was like a Chinese finger puzzle!
With spray lube and putting it in vice, it has to have tension to work, pulling rope out away from it locks rope in place like you said. With rope in close to other ropes releases catch letting rope out.

 

[Fuddy1952]

.

 

[oosik]

Yes - of course. Standing away locks it up - in close frees it up. Not the only thing I got backwards today - HA.

 

[Fuddy1952]

You got it right, I need to work on them to get them working right. They probably haven't been used in 50 years or more!