[TheForge] [OT] Re: Cats, boots (Was: chickens)

[Bruce Freeman]

Quoins look fairly simple.  I have a jar opener that works sort of
like this -- a handle with a spur gear, meshing on opposite sides with
two racks.
For rough work, you might could use two pieces of "soft" square stock,
and a hardened "star" with pointed teeth on a T-handle between them.
Turn the T-handle and the teeth dig into the pieces of soft stock and
move them in opposite directions.

I guess a quoin uses wedge-shaped racks because it's providing
pressure in the other dimension.  But in principal it could be used
either way.

Anyway, you're right.  This is not what I had in mind.  My concept was
like splitting a piece of wood with a wood screw.  Only the split
would already be there and the pieces would be spread forcefully by
the screw.  An alternative to hammering in a wedge.

On Thu, Mar 24, 2011 at 5:37 PM, Mike Spencer <mspencer at tallships.ca> wrote:
>
> Bruce wrote:
>
>> For "wedge" read "screw" and all your objections disappear.
>
> I know this isn't what you're referring to but it's related:
>
> I was fortunate to be able to take "print shop" in 9th grade.  I
> printed up forms for a bogus laboratory that allowed me to order a lot
> of dangerous and otherwise unobtainable chemicals.  But that's another
> story.
>
> The print shop had really cool devices called quoins, pairs of iron
> wedges which, when put together on a flat surface, formed a unit with
> parallel sides and a toothed groove down the center.  The teeth formed
> a kind of diagonal rack gear.  A corresponding tip on a T-handled tool
> made a pinion.  When the hand-set type was ready to go, it was placed
> on a stone surface inside a steel frame -- a "chase" -- and the extra
> space mostly filled with blocks of polished hardwood.  But space was
> left for the quoins, which were inserted loosely and in pairs on at
> least one side and one end.
>
> Then you inserted a wrench -- the pinion-like tool -- into a quoin
> pair and twisted.  That forced the wedge-shaped halves to bypass each
> other and exert enormous force on the block of type.  When this was
> done on both sides or all around, the type was "locked in chase" and
> ready to go to the press.
>
> Alas, I've never come across any of those quoins to put in my tool box
> but I have come across some places where they'd have been handy,
> places where I wanted to exert considerable force from the inside of
> something outward but had severe space limitations.
>
> In earlier centuries, printers used wooden wedges tapped into place
> with a hammer.  The iron ones, though, always impressed me as a
> landmark of technological and blacksmitherly cleverness.
>
> I don't *think* that's way off topic.  Opinions may vary. :-)
>
> - Mike
>
> --
> Michael Spencer                  Nova Scotia, Canada       .~.
>                                                           /V\
> mspencer at tallships.ca                                     /( )\
> http://home.tallships.ca/mspencer/                        ^^-^^
>
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-- 
Bruce
NJ