Ar IMPROVED DRY SLIDE FOR GAS FITTINGS.”
Year: 1875

page_text: LETTERS PATENT to John Parkes Lakin, of Birmingham, in the
County of Warwick, for the Invention of "Ar IMPROVED DRY SLIDE
FOR GAS FITTINGS.”
PROVISIONAL SPECIFICATION left by the said John Parkes Lakin
at the Office of the Commissioners of Patents, with his Petition,
on the 8th October 1875.
I, JOHN PARKES LAKIN, of Birmingham, in the County of Warwick,
do hereby declare the nature of the said Invention for "AN IMPROVED
DRY SLIDE FOR GAS FITTINGS," to be as follows :—
A tube which forms the outside of the gas fitting is provided, and is
bored to the required size in any suitable manner. There is next
provided the usual inner tube, at the top end of which I secure a
metallic piston, which has fitted upon it one, two, or more independent
bevilled edged rings, similar for the most part to metallic pistons as
used in steam engines. These rings are cut through on one side, and
are so constructed that their normal tendency is to spring outwards.

page_text: Thus, as will be understood, although these said rings become worn by
the friction caused by the sliding of the gas fitting their tendency to
spring outwards remains, and in this manner the tube in which they
work remains air-tight and the gas is securely prevented from escaping.
SPECIFICATION in pursuance of the conditions of the Letters Patent
filed by the said John Parkes Lakin in the Great Seal Patent
Office on the 7th April 1876.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
PARKES LAKIN, of Birmingham, in the County of Warwick, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eighth day of October, in the
year of our Lord One thousand eight hundred and seventy-five, in the
thirty-ninth year of Her reign, did, for Herself, Her heirs and succes-
sors, give and grant unto me, the said John Parkes Lakin, Her special
licence that I, the said John Parkes Lakin, my executors, admini-
strators, and assigns, or such others as I, the said John Parkes Lakin,
my executors, administrators, and assigns, should at any time agreo
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 IMPROVED DRY SLIDE FOR GAS FITTINGS," upon the condition (amongst
others) that I, the said John Parkes Lakin, my executors or admini-
strators, by an instrument in writing under my, or their, or one of
their hands and seals, should particularly describe and ascertain the
nature of tho 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 John Parkes Lakin, 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 (that is to say) :-

page_text: '
A tube which forms the outside of the gas fitting is provided, and is
bored or drawn to the required size in any suitable manner. There is
next provided the usual inner tube, at the bottom end of which (not at
the top end as described by mistake in the Provisional Specification) I
secure a metallic piston, which has fitted upon it one, two, or more
independent rings (which may, if desired, be bevilled), similar for the
most part to those used in the construction of metallic pistons employed
in steam engines. These rings are cut through on one side, and are so
constructed that their normal tendency is to spring outwards, inasmuch
as an intervening space is left between the two ends of each ring. Thus,
as will be understood, although although these said rings become worn
by the friction caused by the sliding of the gas fitting their tendency to
spring outwards remains, and in this manner the tube in which they
work remains air-tight, and the gas is thus securely prevented from
escaping.

page_text: understood, that without limiting myself to the precise details herein.
before contained (as these may be to some extent varied or modified
without departing from the nature of my said Invention), I desire it to
he understood that what I claim as the Invention to be protected by
the herein-before in part recited Letters Patent is the application to
dry sliding gas fittings of a metallic packing, in the manner and for the
purpose herein-before described and shewn in the accompanying
Drawings.
In witness whereof, I, the said John Parkes Lakin, have here-
unto set my hand and scal, this Sixth day of April, in the year
of our Lord 1876.
JOHN PARKES LAKIN. (L.S.)
Witness,
R. EMERY DAVIES,
Olerk to Mr. G. R. Holland,
Birmingham.