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Wrench Pattern
When one comes across an object that resembles a commercially
available item but is of such gargantuan size that it seems
unlikely to be usable, the question arises as to whether it
is merely the subject of construction whimsy or simply a technical
exercise. Such was the case when this wrench pattern was added
to the Lee Valley antique tools collection.
In some instances, the most economical manufacturing method
is the foundry system, in which a mold is created and items
are produced by pouring molten metal into the form. There
is no need to create special jigs and fixtures for machining
when a small quantity is required. The sand-casting method
is always employed for small or special runs, as well as for
unusual and complex shapes. This requires a pattern (a true
replica, allowing for shrinkage) of an item to be pressed
into a flask, removed and the resulting depression filled
with an appropriate material. In the case of this wrench,
it was probably cast steel; ordinary cast iron would not have
been a practical choice given the force the jaws would have been subjected to during use.
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Close examination shows "114" in insert numbers
placed on the pattern and a somewhat faded label below. This
barely legible label gives the following information: the
company name "H.B. Underwood", the order number
"09509", the date "11.10.16", the pattern
number "Wrench 114", "No. C.B." (unmarked)
and "No. Loose Pcs." (also unmarked) and, finally,
the "No. Wanted 9". The other side bears an incuse
stamp of the company name. The pattern is 40" long, and
the jaw opening is 6-9/16" wide.
H.B. Underwood & Co. of Philadelphia, Pennsylvania, was
in business until at least 1922. The company advertised as
makers of portable tools. Given the final size
and weight of this wrench, it would be somewhat optimistic
to describe it as portable.
D.S.
Orr
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