IMPROVEMENTS IN THE MANU- FACTURE OF INDIA-RUBBER MATS
Year: 1874

page_text: LETTERS PATENT to Isaac Blue Harris, of Castle Mills, Fountain-
bridge, Edinburgh, for the Invention of "IMPROVEMENTS IN THE MANU-
FACTURE OF INDIA-RUBBER MATS."
Sealed the 25th March 1875, and dated the 7th October 1874.
PROVISIONAL SPECIFICATION left by the said Isaac Blue Harris
at the Office of the Commissioners of Patents, with his .Petition,
on the 7th October 1874.
I, ISAAC BLUE HARRIS, of Castle Mills, Fountainbridge, Edinburgh,
do hereby declare the nature of the said Invention for "IMPROVEMENTS IN
THE MANUFACTURE OF INDIA-RUBBER MATS," to be as follows:-
India-rubber door mats for wiping or cleaning the feet have heretofore
been constructed chiefly in two ways, namely (1), from sheets of rubber
perforated with holes of suitable size and form, and (2) from sheets or
plates of rubber with cells impressed in their surfaces to suitable
depths.

page_text: The defect common to those mats arises from the top surfaces of the
portions of rubber forming the perforations or holes in the one and the
cells in the other being necessarily left continuous, and my present
Invention has for its object the construction of mats free from such
defect, and consists in forming a series of closely set conical or other
shaped projections rising from a sheet of rubber forming the ground
work of the mat, and made in a piece with and thereby holding these
projections.
This form is easily produced by means of a mould, one of the sides
of which is provided with cells corresponding to the projections intended
to be formed on the surface of the mat, into which cells so much of the
rubber (forming the mat) is driven in the process of moulding. That
portion of the rubber which is not driven into those cells forms the
groundwork or back of the mat, and may have any desired thickness.
By this means a much more perfect mat is produced, and moreover, such
mat may be bent round a circular or curved block of wood or metal,
thus admitting of an efficient india-rubber mat for cleaning the sides of
the feet being constructed.
t
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Isaac Blue Harris in the Great Seal Patent
Office on the 6th April 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ISAAC
BLUE HARRIS, of Castle Mills, Fountainbridge, Edinburgh, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Seventh day of October, in the
year of our Lord One thousand eight hundred and seventy-four, in
the thirty-eighth year of her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Isaac Blue Harris, Her
special licence that I, the said Isaac Blue Harris, my executors, ad-
ministrators, and assigns, or such others as I, the said Isaac Blue
Harris, my executors, administrators, and assigns, should at any time

page_text: agree with, and no others, from time to time and at all times there-
after 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 Inven-
tion for "IMPROVEMENTS IN THE MANUFACTURE OF INDIA-RUBBER MATS,"
upon the condition (amongst others) that I, the said Isaac Blue Harris,
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 imme-
diately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Isaac Blue Harris, do hereby declare
the nature of my said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the
following statement, reference being had to the Drawing hereunto
annexed, and to the letters and figures marked thereon (that is to
say) :-
India-rubber door mats for wiping or cleaning the feet have heretofore
been constructed chiefly in two ways, namely (1), from reticulated sheets
of rubber, and (2) from sheets or plates of rubber with cells impressed in
their surfaces to suitable depths.
The defect common to such mats arises from the rubbing surfaces
being unbroken or continuous, and my present Invention has for its
object the construction of mats free from such defect and consists
in a mode of forming them with a series of closely set conical or
other shaped projections rising from a sheet of rubber forming the
ground work of the mat, and made in a piece with and thereby holding
these projections.
In the accompanying Drawing Fig. 1 shews in plan view the mould
which I employ for forming mats, and Fig. 2 is a longitudinal section.
of the same with the parts used in connection therewith for manu-
facturing the mat..
Fig. 3 is a partial plan view on an enlarged scale of the mould, and
Fig. 4 shews in section a portion of the mat made therein.
:

page_text: a, a, is the mould plate through which a series of conical holes, set
at about equal distances apart, are made. These holes form cells
for receiving the plastic india-rubber compound, and they are made.
completely through the metal to ensure the expulsion of the air there-.
from when the india-rubber is pressed into the mould, and of any
residual air as well as of any gas that may be generated by heat during
the process of vulcanization, a provision of the utmost importance in the
successful production of mats with insulated projections on their rubbing:
surfaces. The mould plate a is set in a chase of cast iron b, and it is.
secured therein by filling pieces 6¹ and wedges, which form a raised wall
around the mould plate a..
In using the mould thus constructed I place it upon a press plate
as at c, Fig. 2, interposing between this plate and the mould a layer
of cloth. I then insert in the mould a sheet of plastic india-rubber
of any desired thickness, and over this I lay a piece of cloth to receive
the pressure of the follower plate d of the press, and prevent the india-
rubber adhering thereto.
When pressure is applied to the plastic material through the follower
plate, it will be forced into and caused to fill the conical cells of
the plate a, expelling at the same time any air contained therein
through the holes in the bottom of the plate, and through the cloth
on which the mould is bedded. By this means a perfect cast of the
mould will be ensured.
It only now remains to submit the moulded mass to heat for the
purpose of effecting the change- known in the trade as vulcanizing..
For this purpose I clamp the mould between two plates c, c', and submit
the whole to steam heat in any approved and well-known manner, and
I thus obtain a strong and efficient mat which may be used on a flat
surface like ordinary mats; or may if desired be bent around a circular
or curved block of wood or metal to form a mat suitable for cleaning the
sides and heels of muddy boots.
Having now set forth the nature of my Invention of "Improvements
in the Manufacture of India-rubber Mats," and explained the manner
of carrying the same into effect, I wish it to be understood that under
the above in part recited Letters Patent I claim, the manufacture of

page_text: india-rubber mats with insulated projections on their rubbing surface,
substantially in the manner above described.
In witness whereof, I, the said Isaac Blue Harris, have hereunto
set my hand and seal, the First day of April, in the year of our
Lord One thousand eight hundred and seventy-five.
I. B. HARRIS. (L.S.)