Tirfor mechanism

[jslacoss]

Can anyone explain to me how a tirfor winch works? Specifically, how does the mechanism "back down" a load? A diagram or a picture would be really helpful. I think I understand the theory behind it but I've never actually seen one.

Thanks for the help.

 

[vpl]

This might help:

http://www.lmgtfy.com/?q=Tirfor+winch

BTW, the US name is "Griphoist."

Patricia Lougheed

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[jslacoss]

Gee, thanks.

I have tried looking it up, the closest I've found was a partial cut-away view that didn't show much detail.

http://www.highgearsales.com/Tirfor21.html

I guess I was hoping that someone here might have a little more insight into the specifics of how does the mechanism works while lowering the load. My understanding is that it is a system involving two sets of cam-type grippers or cleats that alternately grip the wire rope with each cycle of the handle. For pulling a load, that seems simple enough.

I guess what I get hung up on is how the load could be pushed through one of these while still gripping with the other in the case of lowering or backing down a load. That makes me think that maybe my mental picture of two cam cleats is a little too simplistic, or that I'm mis-understanding how the thing is actually used.

Thanks.

 

[FeX32]

lmfao. lmgtfy is hilarious!


Fe

 

[MintJulep]

Lifting:

Grip 1, open 2, lift 1, grip 2, open 1, lower 1, repeat

Lowering:

Grip 1, open 2, lower 1, grip 2, open 1, lift 1, repeat