IMPROVEMENTS IN THE MODE OR MEANS OF ATTACHING OR SECURING ARMOUR PLATES TO SHIPS, FORTS, AND OTHER LIKE STRUCTURES
Year: 1876

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields, in the
County of Middlesex, Gentleman, for the Invention of "IMPROVEMENTS IN
THE MODE OR MEANS OF ATTACHING OR SECURING ARMOUR PLATES TO SHIPS,
FORTS, AND OTHER LIKE STRUCTURES." A communication from abroad by
Edouard Pierre Tardy, of Paris, in the Republic of France.
Sealed the 16th March 1877, and dated the 31st October 1876.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson at the
Office of the Commissioners of Patents on the 31st October 1876.
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN THE MODE OR MEANS OF ATTACHING OR SECURING
. ARMOUR PLATES TO SHIPS, FORTS, AND OTHER LIKE STRUCTURES." A com-
munication from abroad by Edouard Pierre Tardy, of Paris, in the Republic of
France.
In order to fasten armour plates to the surfaces or walls which they are destined
to protect various arrangements of screws and bolts are ordinarily employed. In
all these arrangements the screws or bolts pass completely through the plate, and
perforate them with a great number of holes, which considerably diminishes their
strength.
According to this Invention the plate is not completely perforated from side to
side, but only to a certain depth on the side which is in contact with the side of the
ship or other structure to be protected in such a manner as to enable one extremity
of the bolt to be screwed into or attached by any other suitable means to the said
plate, the other extremity being secured to the backing or framework supporting
the armour plate in the ordinary manner.
When the bolts are to be attached to the armour plate by screwing the diameter
of the body of the bolt may be made equal to the external diameter of the screw
thread which enters the armour plate, or the body of the bolt may be made of such
a size that it shall not exceed in diameter that of the bottom of the groove formed
by the screw, thread, in which case it is preferred to make it somewhat smaller.
In some cases when the threaded end which screws into the plate is of larger
diameter than the body the annular or surrounding space which exists between the
Paina 21

page_text: bolt and the sides of the hole in the framework or backing may be filled up by a
tube or any other suitable means; or the space may be obviated by first securing
the bolts to the plate, and then introducing the whole of them into the holes in the
side of the ship or other structure simultaneously from the exterior.
In lieu of attaching the bolts to the plate by screwing they may be secured a
thereto by forming a head on the end of each bolt, which has been previously heated
to redness, and inserting such heads in cavities in the plate, the said cavities being
formed of larger diameter at the bottom than at the top, or the bolts may be attached
in any other suitable manner.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Henry Johnson in the Great Seal Patent Office on the 23rd April
1877.
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN THE MODE OR MEANS OF ATTACHING OR SECURING
ARMOUR PLATES TO SHIPS, FORTS, AND OTHER LIKE STRUCTURES.”
A com-
munication from abroad by Edouard Pierre Tardy, of Paris, in the Republic of
France.
In order to fasten armour plates to the surfaces or walls which they are destined
to protect various arrangements of screws and bolts are ordinarily employed. In
all these arrangements the screws or bolts pass completely through the plate, and
perforate them with a great number of holes, which considerably diminish their
strength.
According to the present Invention the plate is not completely perforated from
side to side, but only to a certain depth on the side which is in contact with
the side of the ship or other structure to be protected in such a manner as to enable
one extremity of the bolt to be screwed into or attached by any other suitable means
to the said plate, the other extremity being secured to the backing or framework
supporting the armour plate in the ordinary manner.
And in order that the said Invention may be fully understood I shall now
proceed more particularly to describe the same, and for that purpose shall refer to
the several Figures on the annexed Sheet of Drawings, the same letters of reference
indicating corresponding parts in all the Figures.
Figures 1, 2, 3, & 4 illustrate different modifications of this Invention, in which
the bolts are attached to the armour plates by screws; and Figure 5 illustrates
another modification in which the bolts are attached to the armour plates without
the intervention of a screw thread.
According to the arrangement illustrated in Figure 1 the diameter of the body a
of the bolt, which passes through the framework or backing b, is made equal to the
external diameter of the screw thread c which enters the armour plate d.
In the modification shewn in Figure 2 the body a of the bolt is made of such a
size that its diameter shall not exceed that of the bottom of the groove formed by
the screw thread c, and it is preferred to make it somewhat smaller.
Figure 3 illustrates another modification resembling that last herein-before
described, but in which the annular space e existing between the bolt a and the
sides of the hole in the framework or backing b, as shown in Figure 2, is filled up
by a tube e¹ or any other suitable means.
Figure 4 illustrates another modification, according to which the formation of the
annular space herein-before referred to is obviated by first screwing the bolts into
the plate d, and then introducing the whole of them into the holes in the side of the
ship or other structure simultaneously from the exterior.
According to the modification illustrated in Figure 5, in lieu of attaching the
bolts to the armour plates by screwing, they are secured thereto by forming

page_text: head on the end of each bolt previously heated to redness, and inserting such heads
in cavities in the plate d, the said cavities being formed of larger diameter at the
bottom than at the top.
Having now described and particularly ascertained the nature of the said Inven-
tion, and the manner in which the same is or may be used or carried into effect, I
would observe in conclusion that I do not confine myself to the precise forms and
arrangements herein-before described and illustrated by the accompanying.Drawings,
as the same may be further modified without departing from the principle of the
said Invention, but what I consider to be novel and original and therefore claim as
the Invention secured to me by the herein-before in part recited Letters Patent is,
the system or mode of attaching or securing armour plates to ships, forts, and other
like structures without completely perforating the plates from side to side, substan-
tially as and for the purposes herein-before described, and as illustrated by the
accompanying Drawings.
In witness whereof, I, the said John Henry Johnson, have to this my
Specification set my hand and seal, this Twentieth day of April, One
thousand eight hundred and seventy-seven.
J. HENRY JOHNSON. (L.S.)