IMPROVEMENTS IN SPRINGS
Year: 1855

page_text: PROVISIONAL SPECIFICATION left by the said John Macintosh at the
Office of the Commissioners of Patents, with his Petition, on the 12th
September 1855.
1, JOHN MACINTOSH, of Great Ormond Street, in the County of Middlesex,
do hereby declare the nature of the said Invention for "IMPROVEMENTS IN
SPRINGS to be as follows:-
This Invention has for its object means of constructing springs for carriages
and other uses, and consists of rendering and employing membranous tissues
or skins flexible and air-proof by saturating in glycerine, and in forming and
enclosing membrane containing air into metal chambers, in such a manner
that by forcing a plunger into chamber, compresses the air without leakage
or strain on the membrane, and thus will greatly improved air springs be
produced.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Macintosh in the Great Seal Patent Office on the
12th March 1856.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
MACINTOSH, of Great Ormond Street, in the County of Middlesex, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twelfth day of September, in the year of our Lord
One thousand eight hundred and fifty-five, in the nineteenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said John Macintosh, Her special licence that I, the said John
Macintosh, my executors, administrators, and assigns, or such others as J, the
said John Macintosh, 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 "IMPROVE-
MENTS IN SPRINGS," upon the condition (amongst others) that I, the said John
Macintosh, 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 John Macintosh, 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 fol-
lowing statement, reference being had to the Drawing hereunto annexed (that
is to say):-
My Invention consists in a new arrangement of air springs. I prepare
membraneous tissue or skins in glycerine, or in glycerine and gelatine mixed
with water, so as to render them pliable and impervious to air, or air-tight.
The skin or membraneous tissue is formed into a bag and put into a cylinder;
a plunger is then inserted into the cylinder, and made to act upon the bag.
This forms an elastic air spring, as shewn in longitudinal section in the accom-
panying Drawing.
A. is the cylinder; B, the plunger; C, the bag. When the plunger is acted

page_text: upon by the buffers of a railway carriage (or otherwise), the air bag is com-
pressed and forms an elastic spring. It will be at once evident that by this
arrangement of air spring all leakage is avoided, and the peculiar rolling action
of the bag prevents any undue wear in the material. In lieu of a bag, I
sometimes fix a diaphragm of similar material in the cylinder, and allow the
plunger to act upon the same. I do not confine myself to the material
specified in the manufacture of the air bag; any other suitable material may
be used.
In witness whereof, I, the said John Macintosh, have hereunto set my
hand and seal, this Twelfth day of March, in the year of our Lord
One thousand eight hundred and fifty-six.
JOHN MACINTOSH. (L.S.)