IMPROVEMENTS IN DOWNTON'S.. SHIP BILGE PUMPS AND FIRE ENGINES
Year: 1862

page_text: LETTERS PATENT to Josiah Stone, of High Street, Deptford, and of
Dowgate Hill, London, for the Invention of "IMPROVEMENTS IN DOWNTON'S..
SHIP BILGE PUMPS AND FIRE ENGINES."
Sealed the IIth November 1862; and dated the 15th May 1862.
PROVISIONAL SPECIFICATION left by the said Josiah Stone at the Office
of the Commissioners of Patents, with his Petition, on the 15th. May
1862.
I, JOSIAH STONE, of High Street, Deptford; and of Dowgate Hill, London;..
do hereby declare the nature of the said Invention for "IMPROVEMENTS IN-
DOWNTON'S SHIP BILGE PUMPS AND FIRE ENGINES," to be as follows:-
My Invention relates to the construction of the crank cams and cam bows,
and the arranging of the same in such a manner that the wear and tear is.
much reduced, noise in working prevented, and the pumps made to work:
more evenly and smoothly. I make the shape of my crank cams as heretofore,.
that is, a triangle with curved sides and the angles rounded off, as shewn in
Fig. I; these cams I place within the crank arms radiating from the centre-
of rotation of the crank shaft in such a manner that one of the projections-
of each cam points directly towards the centre of rotation of the crank shaft,-
as shewn in Fig. 2, the radial lines c, c, c, cutting through the centre of
each cam, that is to say, through the centre of one of its sides and through

page_text: the centre of the rounded angle opposite thereto; and I make my cam bows
of such a shape that when the crank in rotating shall bring each cam in
the position shewn in Fig. 3, that is, when it has completed the downward
stroke, and at the instant of commencing the upward stroke, it shall glide
roller wise round projection of cam bow "A" with scarcely any perceptable
friction until it has completed one-third of the upward stroke, the friction of
the remaining two-thirds of the stroke will then be thrown on the projection
of cam bow "A" and projection of cam "b." The cam bows between the
points "a, a," I make of the same radius as the circle described by the
rotation of the crank, so that when the point of cam marked "6" has passed
the part of cam bow marked "a," the upward stroke is completed, and it
passes on from "a to a" without raising or depressing the buckets or pistons,
by which means the vacuum caused by the upward stroke of the buckets or
pistons has sufficient time to fill before the downward stroke has commenced;
also by disposing the cams in the manner herein-before described, and
assuming them to be modified triangles, the downward pressure on the buckets
or pistons caused by the elastic force of the air contained in the air chamber
is thrown upon their sides from " to 6" while passing from "a to a," as
shewn in Fig. 4, instead of upon their rounded points as in the old method,.
by which means the durability of the parts is increased in proportion to the
difference in the areas of the surfaces liable to friction. The stroke of the
buckets or pistons is preserved in the same proportion, for although the parts
b, b," (see Fig. 4, may be considerably worn by long usuage, the stroke will.
not bo' materially lessened.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Josiah Stone in the Great Seal Patent Office on the
15th November 1862.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOSIAHI
STONE, of High Street, Deptford, and of Dowgate Hill, London, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fifteenth day of May, in the year of our Lord
One thousand eight hundred and sixty-two, in the twenty-fifth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Josiah Stone, Her special licence that I, the said Josiah Stone, my
exccutors, administrators, and assigns, or such others as I, the said Josiah

page_text: Stone, my 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
DOWNTON'S SHIP BILGE PUMPS AND FIRE ENGINES," upon the condition (amongst
others) that I, the said Josiah Stone, my executors or administrators, by an
instrument in writing under my, or their, or one of their bands and seals,
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 Josiah Stone, do hereby declare the
nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement:-
My Invention relates to the construction of the crank cam and cam bows,
and arranging the same in such a manner that the wear and tear is much
reduced, noise in working prevented, and the pumps made to work more
evenly, smoothly, and economically, and tending to keep the pumps in good
working condition for a much longer period than by any former method.
In order that my Invention may be thoroughly understood, I will proceed
to describe the Drawings hereunto annexed, and forming part of this
Specification. I make the shape of my crank cams as heretofore, that is, a
triangle with curved sides and the angles rounded off, as shewn in Fig. I.
These cams I place within the crank arms radiating from the centre of
rotation of the crank shaft, in such a manner that one of the projections of
each cam points directly towards the centre of rotation of the crank shaft,
as shewn in Fig. 2, the radial lines C, C, C, cutting through the centre of each
cam, that is to say, through the centre of one of its sides and through the
centre of the rounded angle opposite thereto; and I make my cam bows of
such a shape that when the crank in rotating shall bring each cam in the
position shewn in Fig. 3, that is, when it has completed the downward stroke,
and at the instant of commencing the upward stroke, it shall glide roller wise
round projection of cam bow "a" with scarcely any perceptible friction until
it has completed one-third of the upward stroke, the friction of the remaining
two-thirds of the stroke will then be thrown on the projection of cam bow
"a" and projection of cam "b." The cam bows between the points " a, a,"
I make of the same radius as the circle described by the rotation of the

page_text: crank, so that when the point of cam marked "6" has passed the part of cam
bow marked "a," the upward stroke is completed, and it passes on from
"a to a" without raising or depressing the buckets or pistons, by which means
the vacuum caused by the upward stroke of the buckets or pistons has
sufficient time to fill before the downward stroke has commenced; also by
disposing the cams in the manner herein-before described, and assuming them
to be modified triangles, the downward pressure on the buckets, or pistons
caused by the elastic force of the air contained in the air chamber is thrown
upon their sides from " to 6". while passing from "a to a," as shewn in
Fig. 4, instead of upon their rounded points as in the old method, see Fig. 5,
by which means the durability of the parts is increased in proportion to the
difference in the areas of the surfaces liable to friction. The stroke of the
buckets or pistons is preserved in the same proportion, for although the parts
"b, b," see Fig. 4, may be considerably worn by long usage, the stroke will
not be materially lessened.
Having now fully described my Invention, and shewn the manner I propose
to carry the same into practical effect, I would have it understood that what
I claim as new, and my Invention, is the placing the cams within the arms of
the crank in the position before described, that is to say, in such a manner
that one of projections of each cam is pointing directly towards the centre
of rotation of the crank shaft, and so that a straight line passing through centre
of such projection and centre of side of cam opposite thereto shall be
perpendicular to centre of rotation of the crank shaft.
In witness whereof, I, the said Josiah Stone, have hereunto set my
hand and seal, this Twenty-ninth day of October, in the year of our
Lord One thousand eight hundred and sixty-two.
Witness,
FREDERICK PHILIP PRESTON,
Counter Hill,
Deptford, S.E.
JOSIAH STONE. (L.S.)