AN IMPROVEMENT IN CASTING THE BEARINGS OR BRASSES OF MACHINERY
Year: 1856

page_text: LETTERS PATENT to William Watson Hewitson, of Headingley, near
Leeds, for the Invention of "AN IMPROVEMENT IN CASTING THE BEARINGS
OR BRASSES OF MACHINERY."
Sealed the 29th April 1856, and dated the 14th February 1856.
PROVISIONAL SPECIFICATION left by the said William Watson Hewitson
at the Office of the Commissioners of Patents, with his Petition, on the
14th February 1856.
I, WILLIAM WATSON HEWITSON, of Headingley, near Leeds, do hereby
declare the nature of the Invention for "AN IMPROVEMENT IN CASTING. THE
BEARINGS OR BRASSES OF MACHINERY," to be as follows:-
This Invention consists of an improvement in casting the bearings or brasses
of machinery; for which purpose, the proper mixture of copper, tin, and zinc
is run into metal or chill moulds, in place of the moulds heretofore used.
O SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Watson Hewitson in the Great Seal Patent Office
on the 14th August 1856.
TO ALL TO WHOM THESE PRESENTS SHALL COME; I, WILLIAM
WATSON HEWITSON, of Headingley, near Leeds, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fourteenth day of February, in the year of our

page_text: Lord One thousand eight hundred and fifty-six, in the nineteenth year
of Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said William Watson Hewitson, Her special licence that I, the said
William Watson Hewitson, my executors, administrators, and assigns, or such
others as I, the said William Watson Hewitson, 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 "AN IMPROVEMENT IN CASTING THE BEARINGS OR BRASSES OF MA-
CHINERY," upon the condition (amongst others) that I, the said William Watson
Hewitson, my executors or administrators, by an instrument in writing
under my, or their, or one of their hands 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 William Watson Hewitson, 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, that is to say:-
This Invention consists of an improvement in casting the bearings or
brasses of machinery; for which purpose, the proper mixture of copper, tin,
and zinc is run into metal or chill moulds, in place of the moulds heretofore
used.
Having thus stated the nature of my said Invention, I will proceed more
fully to describe the manner of performing the same.
It is found that bearings or brasses of machinery composed of copper, tin,
and zinc, which have been cast in either dry or green sand moulds (particularly.
when the bearings or brasses are large), in cooling, the different metals, in place
of being intimately mixed, arrange themselves in groups, and separate more or
less from each other, and the bearings are liable to wear more quickly. Now,
I have discovered that bearings composed of like compounds of copper, tin, and
zine, if cast in metal moulds, or in contact with metal, the combined metals of
the bearings remain more intimately mixed, the bearings last longer and wear
better than when cast in ordinary sand moulds. In making bearings according
to my Invention, I have not thought it generally necessary to apply the metal
surfaces in the moulds to other parts of a brass or bearing than those parts
which are to receive and bear the shaft or axis or other part of a machine;

page_text: and I find it desirable that the chills or metal surfaces should be thinly coated
or washed over with loam, and heated to about 200° Fht. The chills or metal
surfaces are preferred to be of iron, and perforated with small holes, say, from
th to th of an inch in diameter, for the passage of air and vapour. In
preparing a mould for a bearing or brass, I make that portion of the mould
which is to produce the exterior portions of the bearing or brass, of sand, as
heretofore; but for that part of the mould which is to produce the wearing or
bearing surface of the brass I make of metal, and I prefer that such chill or
metal portion of the mould should be as thick as the intended casting, though
a thinner chill may be used. In some cases, particularly when casting
cylindrical bearings or brasses, I have used chills or metal surfaces both for
the inside or wearing surface and for the outside of such bearings, and such
may be the case when casting other forms of brasses or bearings for machinery.
By thus casting bearings or brasses of machinery with metal or chill surfaces,
it will be found that the metals (copper, tin, and zinc,) of which they are
composed are more intimately combined, and that they present a much finer
and more uniform surface to the shaft, axle, or part of machinery working
therein or thereon than can be obtained when such like compounds of metal
are cast into bearings or brasses of machinery in sand moulds without metal or
chill surfaces.
In witness whereof, I, the said William Watson Hewitson, have here-
unto set my hand and seal, this Thirteenth day of August, in the year
of our Lord One thousand eight hundred and fifty-six.
25 Witness,
JNO. COOK,
4, Old Square,
Lincoln's Inn.
WM W. HEWITSON. (L.S.)