Improvements in the Manufacture of Armour-plates.
Year: 1892

page_text: Date of Application, 17th Dec., 1892
Complete Specification Left, 18th Sept., 1893-Accepted, 21st Oct., 1893
PROVISIONAL SPECIFICATION.
[Communicated from abroad by HAYWARD AUGUSTUS HARVEY, of 455, Main
Street, Orange, New Jersey, United States of America, Mechanical
Engineer.]
Improvements in the Manufacture of Armour-plates.
I, HENRY HARRIS LAKE, of the Firm of Haseltine, Lake & Co. Patent
Agents, 45 Southampton Buildings, in the County of Middlesex, do hereby
declare the nature of this invention to be as follows:-
My invention relates to improvements in the manufacture of armour-plates, and
particularly to improvements in the process of producing decrementally-hardened
armour plates set forth in the Specification of prior Letters Patent dated
29th September 1891, No. 16,544 and granted to Henry Harris Lake.
The object of my said invention is to diminish the cost of producing a number of
Buch decrementally-hardened armour-plates, by effecting the decremental car-
burization of two or more plates simultaneously in a single heated chamber, instead
of preparing each plate in a separate chamber and by a separate operation.
According to one method of carrying my invention into practice I dispose within
the heating chamber the plates, and the carburizing and decarburizing material to
operate thereon, in such a manner that the said plates are separated from each
other by layers of carburizing and decarburizing material, in the following
manner :-
A layer of carburizing material is arranged between the contiguous faces of
pairs of plates so as to effect the decremental carburization of both the said faces
simultaneously, and each pair of plates is enclosed, or is separated from adjacent
pairs, by decarburizing material, so that decarburization of the outer face, or back,
of each plate in a pair of plates occurs simultaneously with the decremental
carburization of the front of each plate.
The heating chamber in which the said series of plates is placed, has a layer of
decarburizing material spread over the floor thereof, and upon the said layer the
lowermost plate of the series is laid upon its back. Succeeding plates, separated
from each other and from the said lowermost plate by layers of carburizing and
decarburizing material disposed as aforesaid, are then placed in the chamber. A
covering of sand, clay or other suitable material is placed above the said series of
plates and layers to prevent access of air thereto, and upon the said covering a
weighty layer of fire-brick is placed, to press the carburizing and decarburizing
material and the plates into close contact with each other. This is an important
feature of the process and it will be clearly seen that the weight of the plates and
of the successive layers of carburizing and decarburizing material assists to exert
and maintain the said pressure.
The carburizing and decarburizing material in contact with the faces and backs of
the plates may be arranged to come into contact with such portions of the sides or
edges of the plates as it is desired to affect thereby.
It is obvious that for the decarburizing material disposed as hereinbefore described,
1 may substitute either neutral material, or carburizing material. In the former
instance one side only of the plate will be operated upon, and in the latter case
both sides of the plate will be carburized.
The operation of raising the heating chamber and its contents to the high
temperature which is an essential condition of the process, takes, under ordinary
conditions of working, slightly longer thau if only one plate were dealt with at a
time, but the treatment of the series of plates, subsequent to the production of the

page_text: said high temperature, occupies no longer time than the like treatment of one plate.
It is therefore evident that by the use of the process hereinbefore explained, a very
considerable saving of expense will result, inasmuch as two or more armour plates
can be produced in a period but little longer than that hitherto occupied in the
production of one plate, and by the use of plant of dimensions very little greater 5
than the dimension of the plant required for the production of plates singly.
Dated this 17th day of December 1892.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Armour-plates.
1, HENRY HARRIS LAKE, of the Firm of Haseltine, Lake & Co., Patent
Agents, 45 Southampton Buildings, in the County of Middlesex, do hereby
declare the nature of this invention and in what manner the same is to be
performed to be particularly described and ascertained in and by the following
statement:
My invention relates to improvements in the manufacture of armour-plates, and
particularly decrementally-hardened armour plates such as those set forth in the
Specification of prior Letters Patent dated 29th September 1891, No. 16,544, and
granted to Henry Harris Lakė.
The object of my said invention is to diminish the cost of producing a number
of such decrementally-hardened armour-plates by effecting the decremental car-
burization of two or more plates simultaneously in a single heated chamber, instead
of preparing each plate in a separate chamber and by a separate operation.
In order that my said invention may be clearly understood I will now proceed to
describe the same with reference to the accompanying drawing, which illustrates in
longitudinal vertical section a charged heating-chamber with its contents arranged
according to oue method of carrying my invention into practice.
A is the heating chamber, B B are the plates.
According to one method of practising my invention a layer of carburizing
material C is arranged between the contiguous faces B' of pairs of plates, and each
pair of plates is enclosed or is separated from adjacent pairs, by decarburizing
material D which is in close contact with the back B of each plate.
In charging the chamber A in which the said series of plates is placed, a layer
of decarburizing material is spread over the floor thereof, and upon the said layer
the lowermost plate of the series is laid upon its back. The succeeding plates,
separated from each other and from the said lowermost plates by layers of
carburizing and decarburizing material disposed as aforesaid, are then placed in the
chamber. The top layer of carburizing or decarburizing material will prevent
access of air to the plates and the succeeding layers, and upon the said top layer a
covering of fire-brick F or other suitable material is placed to thoroughly seal and
render air-tight the said chamber A. The employment of pressure is an important
feature of the process and it will be clearly seen that the weight of the plates on
the successive layers of carburizing and decarburizing material exerts and maintains
a very great pressure which acts to keep the said plates in the closest possible
contact with the carburizing and decarburizing material; the said material is
pressed into close contact with the uppermost plate of the series by the weight of
the aforesaid layer of fire-brick.
The carburizing and decarburizing material in contact with the faces and backs
of the plates may be arranged to come into contact with such portions of the sides
or edges of the plates as it is desired to affect thereby.
The chamber and its contents after being thus charged are raised to a very high
temperature, and maintained thereat for the required length of time, so that the

page_text: decremental carburization of both the contiguous faces B¹ of each pair of plates,
and decarburization of the outer faces B' of each pair, occurs simultaneously.
It is obvious that for the decarburizing material disposed as described with
reference to the drawing, I may substitute either neutral material, or carburizing
material. In the former instance one side only of the plate will be operated upon,
and in the latter case both sides of the plate will be carburized.
The operation of raising the heating chamber and its contents to the high
temperature which is an essential condition of the process, takes, under ordinary
conditions of working, slightly longer than if only one plate were dealt with at a
time, but the treatment of the series of plates, subsequent to the production of the
said high temperature, occupies no longer time than the like treatment of one
plate. It is therefore evident that by the use of the process hereinbefore explained,
a very considerable saving of expense will result, inasmuch as two or more armour-
plates can be produced in a period but little longer than that hitherto occupied in
the production of one plate, and by the use of plant of dimensions very little
greater than the dimensions of the plant required for the production of a single
Harvey plate.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, as communicated to ine
by my foreign correspondent, I declare that what I claim is :-
In the manufacture of armour-plates the treatment of two or more plates
simultaneously in a heating-chamber so as to produce a decremental carburization
of the same for the purposes specified.
1000
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.