IMPROVE- MENTS IN MANUFACTURING CURVATED ARMOUR PLATES AND OTHER IRONWORK, AND IN MACHINERY OR APPARATUS EMPLOYED THEREIN
Year: 1863

page_text: PROVISIONAL SPECIFICATION left by William Littell Tizard at the
Office of the Commissioners of Patents, with his Petition, on the 4th
March 1863.
I, WILLIAM LITTELL TIZARD, of Birmingham, in the County of Warwick,
Engineer, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN MANUFACTURING CURVATED ARMOUR PLATES AND OTHER IRONWORK, AND
IN MACHINERY OR APPARATUS EMPLOYED THEREIN," to be as follows:-
These improvements consist in a new mode of making curved or crooked
iron and steel plates, beams, and other metalwork, whereby uniform strength
and tenacity of the inner and outer sides of the curve are ensured.
By the usual mode of bending iron the convex part of the curve is unduly
stretched and the fibre of the metal often broken and at the same time its
opposite or concave side is compressed by the operation to such a degree, as
to crush the fibres into a heterogeneous mass, this deterioration increases with
the extent of the curve and also with the thickness of the plate or other iron-
work so maltreated. These two adverse and equally destructive effects are
entirely prevented by my present Invention which I proceed to describe.
Instead of bending the iron plate or other metalwork after it is rolled to
its requisite thickness, as has been the universal practice heretofore, I bend a
number of thin plates, either hot or cold, to their necessary curvatures and
forms by means of an ordinary iron plate bending machine, the outside plate
having a greater radius than the inner, and the same object is observed
with all the intermediate plates. The two outside plates are provided with
projections or fins which are made to lap over the edges of the whole, to

page_text: keep them together, but if other clamps are used they are unnecessary.
These thin plates are piled one on the other in due order and subjected to a
welding heat in an ordinary furnace, and then welded together without
materially altering their respective shapes during the process. The pile of
plates is placed into the furnace on its edge, but this position may be changed
with proper appliances for removal. The welding process is effected by one or
other of the following means:-
First, by the mass being passed when in a welding state through three,
four, or more pairs of rolls, which are placed in a curvilinear position (in
relation to each pair), each pair of rolls being made adjustable to suit the
various curves and thicknesses of the plates to be made.
Secondly, by the mass being subjected to similar squeezing between a large
roll and three, four, or smaller rolls which are made to revolve near the periphery
of the large roll the distances of the small rolls therefrom are regulated to suit
the thickness of the metal by means of raising and depressing screws similar
to those on ordinary rolls. The diameter of the large roll corresponds with the
inner radius of the curved plate, and is reduced or enlarged by removing or
adding the segments of a cylinder which are bolted on the core or smallest
cylinder. The spur wheel on the large roll works a pair of "idle wheels
which communicate motion to the small front roll. The spur wheel on the
small leading roll occasionally requires changing with the diameters of the
large roll, the speed of the latter (not revolutions, but number of feet it
travels per minute) being always a little less than the former in consequence
of the greater length of the outer curve of the plate. These rolls may be
worked vertically, but not necessarily so. For small crooked hollow and flat
work, I sometimes use presses and either their bed plates or top tools may be
worked by any known power, steam, hydraulic, screw, or wedge, the right
application of which to the above purposes is known to an ordinary mechanic.
Ribbons of iron might be wound round and welded on to each other and thus
form the tyres of railway and other wheels.