In- PROVEMENTS IN SCREW BOLTS, BOLT HOLES, NUTS, AND WASHERS FOR ARMOUR- PLATED STRUCTURES.”
Year: 1869

page_text: LETTERS PATENT to William Palliser, of the Army and Navy Club,
Pall Mall, in the County of Middlesex, and Thomas English, of
Wandsworth, in the County of Surrey, for the Invention of "In-
PROVEMENTS IN SCREW BOLTS, BOLT HOLES, NUTS, AND WASHERS FOR ARMOUR-
PLATED STRUCTURES.”
PROVISIONAL SPECIFICATION left by the said William Palliser and
Thomas English at the Office of the Commissioners of Patents,
with their Petition, on the 23rd April 1869.
We, WILLIAM PALLISER, of the Army and Navy Club, Pall Mall, in
the County of Middlesex, and THOMAS ENGLISH, of Wandsworth, in
the County of Surrey, do hereby declare the nature of the said Inven-
tion for "IMPROVEMENTS IN SCREW BOLTS, BOLT HOLES, NUTS, AND WASHERS
FOR ARMOUR-PLATED STRUCTURES," to be as follows:-
Our Invention consists in the application of nuts having spherical
bearing surfaces to bolts constructed in accordance with the Invention
for which Letters Patent were granted to one of us, bearing date the
6 Dec. 1862, No. 3281, that is to say, bolts which are constructed

page_text: so that the extension due to any strain shall take place along the shank.
By the employment of such spherical nuts the direction of the bolt in
relation to the armour plate held thereby is capable of any required
change consequent upon the lateral displacement or the bulging when
struck by a projectile of any part of the armour or backing, and thus
the bolt and nut are not subjected to any cross strains from this cause.
In employing the said screw bolts constructed according to the before-
mentioned Patent we prefer to reduce the area of the shank by cutting
the screw thread (by preference of a rounded form) along the entire
length of the bolt, in which case, in place of the ordinary head of the
bolt we provide a separate head or nut with spherical bearing surface
screwed on to the end of the bolt. For the seat of such spherical nut
or head we form a corresponding recess with spherical bottom surface
in the armour plate, and for the connection of the nut with the back of
the structure we either form a similar spherical recess in the bearing
surface, or we interpose between this surface and the nut a washer
having a spherical recess or seat for the nut. If necessary we strengthen
such washer against the bursting strain caused by the spherical form of
the nut by surrounding it with a close helical coil of some ductile metal,
the connection between the washer and the coil being effected by forming
a screw thread on the circumference of the washer fitting into a corre-
sponding female thread on the coil; such thread is formed to run in the
same direction as the coil, and is of a quicker pitch than the latter. In
constructing such spherical nuts we prefer to chamfer off the inner
circumference of the nut at the bearing end, in order to distribute the
strain between the nut and bolt along several threads, and to prevent
the whole strain being applied to the bolt at one point. For screwing
the nut on or off the bolt the upper end thereof may be made polygonal
so as to be turned with a spanner, or notches or holes may be formed in
the end surface for this purpose. It is obvious that such spherical nuts
can also be employed in combination with bolts of ordinary form,
although such bolts would not be applied with such advantage as the
bolts made according to the before-mentioned Patent.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Palliser and Thomas English in the Great
Seal Patent Office on the 21st October 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, WILLIAM
PALLISER, of the Army and Navy Club, Pall Mall, in the County of
Middlesex, and THOMAS ENGLISH, of Wandsworth, in the County of
Surrey, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-third day of April, in the year
of our Lord One thousand eight hundred and sixty-nine, in the thirty-
second year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto us, the said William Palliser and Thomas English,
Her special licence that we, the said William Palliser and Thomas
English, our executors, administrators, and assigns, or such others as
we, the said William Palliser and Thomas English, our executors,
administrators, and assigns, should at any time agree with, and no
others, from time to time and at all times thereafter during the term
therein expressed, should and lawfully might make, use, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN
SCREW BOLTS, BOLT HOLES, NUTS, AND WASHERS FOR ARMOUR-PLATED STRUC-
TURES," upon the condition (amongst others) that we, the said William
Palliser and Thomas English, our executors or administrators, by an
instrument in writing under our or their hands and scals, or under the
hand and seal of one of us or them, should particularly describe and
ascertain the nature of the said Invention, and in what manner the
same was to be performed, and cause the same to be filed in the Great
Seal Patent Office within six calendar months next and immediately
after the date of the said Letters Patent.
NOW KNOW YE, that I, the said William Palliser, on behalf of
myself and the said Thomas English, do hereby declare the nature of
the said Invention, and in what manner the same is to be performed,
to be particularly described and ascertained in and by the following
statement thereof, reference being had to the accompanying Sheet of
Drawings, and to the figures and letters marked thereon, that is to
say:-
Our Invention consists in the application of nuts having spherical

page_text: bearing surfaces to bolts constructed in accordance with the Invention
for which Letters Patent were granted to one of us, bearing date the
6th Dec. 1862, No. 3281, that is to say, bolts which are constructed
so that the extension due to any strain shall take place along the shank.
By the employment of such spherical nuts the direction of the bolt in
relation to the armour plate held thereby is capable of any required
change consequent upon the lateral displacement or the bulging when
struck by a projectile of any part of the armour or backing, and thus
the bolt and nut are not subjected to any cross strains from this
cause.
In employing the said screw bolts constructed according to the before-
mentioned Patent we prefer to reduce the area of the shank by cutting
the screw thread (by preference of a rounded form) along the entire
length of the bolt, in which case in place of the ordinary head of the
bolt we provide a separate head or nut with spherical bearing surface
screwed on to the end of the bolt. For the seat of such spherical nut
or head we form a corresponding recess with spherical bottom surface in
the armour plate, and for the connection of the nut with the back of
the structure we either form a similar spherical recess in the bearing
surface, or we interpose between this surface and the nut a washer
having a spherical recess or seat for the nut. If necessary we strengthen
such washer against the bursting strain caused by the spherical form of
the nut by surrounding it with a close helical coil of some ductile metal,
the connection between the washer and the coil being effected by forming
a screw thread on the circumference of the washer fitting into a corre-
sponding female thread on the coil; such thread is formed to run in the
same direction as the coil and is of a quicker pitch than the latter. In
constructing such spherical nuts we prefer to chamfer off the inner
circumference of the nut at the bearing end, in order to distribute the
strain between the nut and bolt along several threads, and to prevent
the whole strain being applied to the bolt at one point. For screwing
the nut on or off the bolt the upper end thereof may be made polygonal
so as to be turned with a spanner, or notches or holes may be formed in
the end surface for this purpose. It is obvious that such spherical nuts
can also be employed in combination with bolts of ordinary form,
although such bolts would not be applied with such advantage as the
bolts made according to the before-mentioned Patent.

page_text: bolt A with reduced shank, the nut B of which is constructed with a
spherical bearing surface according to our Invention. The inner circum-
ference of the nut at the bearing end is by preference chamfered off, as
shewn at b, for the purposes before mentioned. For screwing the nut
on and off the end surface may have notches or recesses 6', 61, formed
therein, as shewn in the end view, Figure 2, for the introduction of a
key, or the front end of the nut may be made polygonal, as shewn in red
lines, to be turned by an ordinary spanner. The bolt may be provided
with an ordinary head at the other end, but by preference we arrange
the same as shewn at Figure 3, where the bolt A has a screw thread
formed along its entire length, and has a separate head or second nut C
screwed on its other end, which nut also has a spherical bearing surface
fitting into a recess with corresponding spherical bottom surface formed
in the armour plate D; or such separate head C and recess in the
armour plate may be formed conical or tapering, as at Figure 5. The
nut B may either bear against a spherical recess in the backing E or
against a washer F with a spherical recess, as shewn. Such washers
may be strengthened against the bursting strains put upon it by the nut
by screwing upon its outer circumference a close helical coil of ductile
metal, as shewn at G in the section of the washer at Figure 4, the screw
thread being made to run in the same direction as but of a quicker pitch
than the coil.
Having thus described the nature of our Invention, and in what
manner the same is to be performed, what we claim under the herein-
before in part recited Letters Patent is,-
First. Constructing the nuts of armour plate bolts with spherical
bearing surfaces, substantially as set forth.
Second. Chamfering off the inner circumference of the bearing end
of nuts with spherical bearing surfaces, substantially as and for the
purposes set forth.
Third. Constructing armour plate bolts having spherical nuts with a
separate head or second nut screwed on to the bolt which has a screw
thread formed along its entire length, substantially as set forth.
Fourth. Securing armour plates by means of bolts having heads with
spherical bearing surfaces fitting into recesses with spherical surfaces
formed in the armour plates, substantially as set forth.

page_text: Fifth. Constructing washers for spherical nuts with a close metal
coil screwed on to the outer circumference thereof, substantially as
described.
In witness whereof, I, the said William Palliser, have hereunto
set my hand and seal, this Nineteenth day of October, in the
year of our Lord One thousand eight hundred and sixty-nine.