IMPROVEMENTS IN THE MANUFACTURE OF BALLS TO BE USED FOR THE GAME OF LAWN TENNIS
Year: 1876

page_text: LETTERS PATENT to Robert Hammond, of Hayes, in the County of Middlesex,
for the Invention of "IMPROVEMENTS IN THE MANUFACTURE OF BALLS TO BE
USED FOR THE GAME OF LAWN TENNIS."
Sealed the 21st November 1876, and dated the 26th May 1876
PROVISIONAL SPECIFICATION left by the said Robert Hammond at the Office
of the Commissioners of Patents on the 26th May 1876.
ROBERT HAMMOND, of Hayes, in the County of Middlesex. "IMPROVEMENTS IN
THE MANUFACTURE OF BALLS TO BE USED FOR THE GAME OF LAWN TENNIS."
This Invention consists in certain improvements in the manufacture of balls to
be employed in the game of lawn tennis, whereby the necessity of sewing or
stitching is entirely avoided, whilst the balls are rendered wholly impervious to
moisture.
For the manufacture of the balls a sheet of woollen or cotton fabric is provided
and laid over hot metallic cylinders, a layer or layers of india-rubber in solution
being then applied to the surface thereof and spread thereon by the ordinary
and well-known means and appliances, pressure being used for the purpose of
consolidating and firmly uniting the india-rubber with the woven fabric employed.
Instead of a woven fabric being used as before mentioned woollen flock may be
used, in which case the same is spread upon hot plates and then india-rubber
in solution applied thereto, pressure being then exerted thereon to consolidate
the same, until the requisite thickness has been attained. The sheets having
"double
been thus prepared are allowed to cool, and are cut into pieces of a
tongue" shape, two of such pieces when the respective edges thereof are placed
together forming a ball. The pieces thus cut are afterwards seasoned, and then
fitted into metallic moulds formed of hemi-spherical portions, and in which is placed
a sufficient quantity of sulphur in powder for the vulcanization of the india-rubber.
The moulds are then subjected to hydraulic or other pressure, so as to bring the
respective hemi-spherical parts into close contact, and whereby the edges of the

page_text: double tongue-shaped pieces will be caused to adhere. The moulds with the balls
contained therein are then placed in a valcanising chamber (the nature of which is
well known and understood) and permitted to remain therein until the india-rubber
is sufficiently vulcanized.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Robert Hammond in the Great Seal Patent Office on the 25th Novem-
ber 1876.
ROBERT HAMMOND, of Hayes, in the County of Middlesex.
"IMPROVEMENTS IN
THE MANUFACTURE OF BALLS TO BE USED FOR THE GAME OF LAWN TENNIS."
My said Invention consists in certain improvements in the manufacture of balls
to be employed for the game of lawn tennis, whereby the necessity of sewing or
stitching is entirely avoided, whilst the balls are rendered wholly impervious to
moisture.
One mode of manufacturing. balls in accordance with my said Invention is as
follows: A sheet of woollen, cotton, or other suitable woven fabric is provided, the
same being laid over hot metallic cylinders. A layer or layers of india-rubber in
solution, mixed with the requisite quantity of sulphur for the process of vulcanizing
(as will be well understood), is or are then applied to and spread over the surface of
the fabric by the ordinary and well-known means and appliances so as to obtain
any proper or desired thickness, such pressure as may be necessary being used for
the purpose of consolidating and firmly uniting the india-rubber with the woven
fabric employed. The sheet having been thus prepared is laid on a table, and is
cut by means of cutting punches or shears into pieces or segments of a double
tongue shape, two of such pieces when the respective edges thereof are brought
into contact and fitted and united together by means of a solution of india-rubber
forming a hollow ball. The ball thus made is placed in a strong metallic mould
composed of hemi-spherical portions, which are firmly screwed together, and then
placed in the vulcanizing apparatus or steam boiler and allowed to remain therein
at a temperature of 280° Fah. or thereabouts for the india-rubber to become
well and sufficiently vulcanized, as will be well understood by persons conversant
with such manufactures. When removed from the moulds the hollow balls become
firm and permanently elastic, and are then inflated to the degree of hardness
required for the purpose for which they are to be used.
Instead of a woven fabric being used as before mentioned another mode of
manufacturing the hollow balls in accordance with my said Invention is as follows:-
A sheet of india-rubber is spread and cut as before described into segments, and the
Whilst the balls
edges thereof caused to adhere by means of india-rubber solution.
""
which have been so formed, and before they are moulded, and when in a "tacky
state, a coating of ground flock, or cork, or sawdust is applied thereto by means of
a-brush. The hollow balls are then placed in an oven or drying chamber in which
they are dried by the application of heat. They are then placed in the moulds and
vulcanized as before described.
Having thus declared and ascertained the nature of my said Invention and in
what manner the same is to be performed, I would observe in conclusion that I do not
claim the manufacture of ordinary india-rubber hollow balls made with india-rubber
alone, but what I consider novel and original, and therefore claim as constituting the
Invention secured to me by the said herein-before in part recited Letters Patent
are,―
1st. The manufacture of hollow inflated india-rubber balls moulded and vul-
canized and covered with a woven fabric, substantially as and for the purposes
herein-before described and set forth.

page_text: 2ndly. The manufacture of hollow inflated india-rubber balls covered with
ground flock, or cork, or sawdust, and moulded and valcanized, substantially as and
for the purposes herein-before described and set forth.
In witness whereof, I, the said Robert Hammond, have hereunto set my hand
and seal, this Twenty-fourth day of November, in the year of our Lord One
thousand eight hundred and seventy-six.
Witness,
FRED. TAPLIN,
Auctioneer,
68, St. John's Wood Road. .
N.W.
ROBERT HAMMOND. (L.S.)