AN IMPROVED PROCESS AND APPARATUS FOR Hardening, Tempering, and ANNEALING Steel and OTHER METALS
Year: 1873

page_text: PROVISIONAL SPECIFICATION left by Samuel Shaw Lewis at the
Office of the Commissioners of Patents, with his Petition, on the
15th November 1873.
I, Samuel Shaw LEWIS, of the City and State of New York, United
States of America, now of No. 8, Southampton Buildings, London, do
hereby declare the nature of the said Invention for "AN IMPROVED
PROCESS AND APPARATUS FOR Hardening, Tempering, and ANNEALING Steel and
OTHER METALS," to be as follows:-
My Invention relates to a novel process and apparatus for hardening
steel, iron, and compounds of the same, gun metal, and phospor bronze;
it is chiefly designed for hardening, tempering, and annealing sheets or
slabs made up of layers of iron and steel combined by welding for
forming the walls of burglar-proof safes and vaults, or for employment as
defensive armour plates for war vessels and fortifications; but the said
Invention is also applicable for the hardening or tempering of machine
tools and other implements or utensils and for other like purposes.
One method of carrying my said Invention into practise consists in
subjecting the hot metal to be hardened or tempered to the action of a
cold current or blast maintained under pressure, while it acts on the

page_text: heated metal by means of a head or force checked from the delivery
or outlet so that the current or blast will press against the heated metal
and will flow past it rapidly, changing quickly the heated atoms of the
current for cold atoms and thus rapidly absorbing and carrying off the
caloric from the heated metal. The pressure is regulated by means of
valves, cocks, or other similar appliances.
I prefer to employ a current of water which may be supplied from a
head or by a pump or otherwise; I may also employ other liquids or
various fluid mixtures, and substances soluble in water may be mixed
therewith, or I may use currents or blasts of air, gas, or vapour
separately or combined with other substances.
My improved apparatus has a trough designed to receive and hold the
heated plate; this trough has an inclination so that if the cooling
medium is a liquid it may drain freely from below the lower edge of the
plate which rests on a grid or scries of bars. In recesses in the sides of
the trough are fitted two adjustable vertical plates; the said plates are
provided on their adjacent faces with pins or studs which come into
contact with the sides of the hot metal plate and keep the surfaces of
the same from the surfaces of the adjustable plates so as to permit the
cooling current to flow freely past the heated metal. These pins or
studs are longer where the cooling current first strikes the heated plate
than at the other end of said plate, thus forming passage ways which
gradually contract.
The top of the trough is provided with a cover or door which when
opened allows the heated plate to be lowered into the trough till it rests
on the aforesaid bars. Screws are coupled to the said plates to retract
them readily as well as press them toward each other; or in place of
the screws toggle joints may be used; the said toggle joints may have
their resisting pivots made movable to adapt them to operate on
plates of any thickness. At its outlet end the aforesaid trough is
provided with a suitable check or valve made adjustable to contract the
delivery from the trough to any desired extent.
If the cooling medium is to be a liquid supplied from a cistern or
reservoir or head, the inlet end of the trough is provided with a valve
or gate which is turned or opened as soon as the plate is fixed in place
and the cover closed and secured; then the liquid fills the trough
instantly, and flowing past the plate on all its surfaces abstracts its heat

page_text: very quickly and hardens or tempers the plate, discharging the abstracted
caloric with the current which escapes past the check. If the cooling
current is to be supplied by the action of a pump, fan, or bellows the
said valve or gate may be dispensed with. To keep the lower edge of
the plate from lodging on the aforesaid studs as it is lowered into the
trough suitable temporary fenders are employed.
Near the check valve in the trough I place bars against which the
end of the heated plate abuts; these bars keep the plate from being
moved along in the trough toward the check valve by the force of the
cooling current.
The water or other fluid used need not be wasted but may be collected
as it flows past the heated plate, and may be used repeatedly by being
pumped back into the elevated reservoir, which if necessary may be
supplied with ice or other refrigerating substance.