[ my drawing ]
>>
>> /\ /\
>> #| |X X| |#
>> # \/ X X \/ #
>> XXXXXXX XXXXXXX
>> XX XX
>> XX -> this way XX <- this way
>> XX XX
>>
>> Where # is the sliding jaw, and the Xs are the wrench, including the
>> fixed jaw. The arrows are showing direction of handle travel.
>Uh, did you mean to show the *wrong* way to use a "Whitworth" (cresent)
>wrench? This is just the opposite of what I've always believed is the
>"right way", so that the "sliding jaw is getting less of the load" where
># is the sliding jaw.
Ok, as someone else pointed out to me, it isn't really "less of the
load", it's keeping the load parallel to the direction of travel of
the sliding jaw. In turning the wrench, you want the sliding jaw to
be contacting the bolt on its lower corner (relative to the above
picture). I'm terrible at drawing ascii pictures, but I'll try
again.
/ \
/ #/ \X
/ #|a |X
V #| |X
#|b |X
<- #\ /X
# \ / X
## \ / XX
XXXXXXXXXXX
You want the jaw to be applying force at (b), not (a). THis means
the slding jaw is getting a force similar to the lower arrow, not the
upper one.
>(er, that is, *If* I were ever to use one, I'd never use anything like a
>Cresent wrench on any of *my* cars! ;-)
They work great on the oil lines, other BSP fittings. I use them on
occasion for large nuts, and they're especially useful for
tightening regulators and attachments on gas cylinders.
andy
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