CERTAIN IMPROVEMENTS IN METALLIC PISTONS
Year: 1854

page_text: LETTERS PATENT to William Brunton, of Camborne, in the County of
Cornwall, Civil Engineer, for the Invention of "CERTAIN IMPROVEMENTS
IN METALLIC PISTONS."
Sealed the 8th December 1854, and dated the 20th June 1854.
PROVISIONAL SPECIFICATION left by the said William Brunton at the
Office of the Commissioners of Patents, with his Petition, on the 20th
June 1854.
I, WILLIAM BRUNTON, do hereby declare the nature of the said Invention
for "CERTAIN IMPROVEMENTS IN METALLIC PISTONS" to be as follows:-
These improvements consist in tightening up the piston rings, whenever
required, without the labour of taking off cylinder cover and junk ring of piston,
at the same time securing equal pressure on each spring or other power re-
quired to force out the piston rings during the said process of tightening, thus
effecting saving in the time and labour required for taking off cylinder cover
and junk rings, making fresh joint, &c.; and also in the perfect security there
will be in baving each spring or other power increased equally, (which cannot
be effected by hand,) thereby ensuring an equal pressure over the whole piston
ring, and in consequence the even wear of the inside of the cylinder.
In illustration of the nature of the said Invention, I now stato that the
above may be effected by having a plug grooved to correspond in number

page_text: with the springs in the piston, fitting into a holo in the centre of piston; the
bolts which are connected to the springs rest in these grooves. When the
piston is first inserted, they are placed in the deepest part of the groove or
bottom of inclined or wedge-like part.
Through the plug a screw is inserted, having a conical collar, which is
fitted and ground into the inside of the junk ring, a square lead to the screw
going through and extending some 14 inch outside of junk ring. In the centre
of the cylinder cover 1 have a hole, large enough to insert a box spanner,
which would fit the head of screw extending out of junk ring, into which hole
a plug is inserted when the engine or other machine is at work. When the
piston requires tightening up, the plug in cylinder cover is taken out, and a
box spanner inserted; and by unscrewing the screw which is in the plug in
centre of piston, the plug is made to return inwards, and the bolts attached
to the spring forced to a greater distance from the centre of piston by the
inclined grooves in the said plug, thus tightening up the springs. In
vertical engines, or other machines where the piston is accessible only from
the top, a centre screw and plug cannot be placed, but I insert four or more
screws, according to the number of springs in piston working in wedges, thus
tightening the rings, upon the same principle as above.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Brunton in the Great Seal Patent Office on the
18th December 1854.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
BRUNTON, of Camborne, in the County of Cornwall, Civil Engineer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twentieth day of June, in the year of our Lord
One thousand eight hundred and fifty-four, in the eighteenth year of
Her reign, did, for Herself, Her heirs and successors, give and grant
unto me, the said William Brunton, Iler special licence that I, the said
William Brunton, my executors, administrators, and assigns, or such others
as I, the said William Brunton, 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

page_text: Britain and Ireland, the Channel Islands, and Isle of Man, an Invention for
"CERTAIN IMPROVEMENTS IN METALLIC PISTONS," "pon the condition (amongst
others) that I, the said William Brunton, by an instrument in writing under
my hand and seal, 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 Brunton, do hereby declare
the nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement, that is to say :-
The nature of this Invention, as heretofore described in the Provisional
Specification already filed, is now re-stated in manner following (viz') :—
My improvements consist in a method by which the piston rings of metallic
pistons can be tightened up, whenever required, without the labor of taking
off the cylinder cover and junk ring of the piston, at the same time in-
suring equal pressure upon each spring or other power required to force
out the piston rings during the said process of tightening, thus effecting the
saving in time and labor required in taking off the cylinder cover and
junk rings, making fresh joints, &c.; and also in the perfect security there
will be in having each spring or other power increased equally, (which
cannot be effected by hand,) thereby insuring an equal pressure over the
whole piston ring, and in consequence the even wear of the inside of the
cylinder. The method by which the above is performed is having a plug
fitting into a round hole in the centre of the piston, which plug is grooved
with the same, number of grooves as there are springs in the piston, and
which grooves are not cut parallel with the outside of the plug, but deep at
one end and run out to nothing at the other, forming an inclined plane or
wedge; the bolts which are connected to the springs rest in these grooves.
When tho piston is first inserted, they are placed in the deepest part of the
groove or bottom of the incline. Through the plug a screw is inserted,
having a conical collar, which is fitted and ground into the inside of the junk
ring of piston, a square head to the screw going through and extending some
one and half inch outside the junk ring. In the centre of the cylinder cover I
have a hole, large enough to insert a box spanner, which would fit the head of
screw extending out of junk ring, into which hole a plug is inserted when the
engine or other machine is at work. When the piston requires tightening up,
the plug in cylinder cover is taken out, and a box spanner inserted; and by
unscrewing the screw which is in plug in centre of piston, the plug is made to

page_text: retire inwards, and the bolts attached to springs are forced to a greater distance
from the centro of piston by the inclined grooves in the said plug, thus
tightening up the springs.
In vertical engines, or other machines where the piston is accessible only
from the top, a centre screw and plug cannot be placed, but I insert four
or more screws (according to the number of springs in piston) working
in wedges, thus tightening the rings, upon the same principle as before
mentioned.
In the accompanying Drawing a, a, shew the piston rings, and e, e, the
springs as used in a locomotive engine; f, f, tightening bolts, ensuring equal
pressure upon the said springs c, c; the said tightening bolts f, f, working in
the incline grooves d, d, being pushed outwards from the centre of the piston
by the descent of the plug 6 in the hollow in the top of the piston rod c, and
which descent is caused and regulated by the screw 9 working through the
plug b, as already explained in the foregoing Specification.
Having now described the nature of the said Invention, and in what manner
the same is to be performed, I hereby further declare that, with regard to the
said Invention above described and illustrated by the accompanying Drawing,
I do not claim the arrangement and construction of the piston rings (a, a,) or
the springs (c, e); but I do claim the method of insuring equal pressure
upon the said springs (e, e,) by means of the tightening bolts (f,f), and the
other arrangements conjoined therewith, when employed and used for the
purposes herein-before set forth, as constituting my said Invention.
In witness whereof, I, the said William Brunton, have hereunto set my
hand and seal, this Thirteenth day of December, in the year of our
Lord One thousand eight hundred and fifty-four.
Witness to the signature of Wm. Brunton,
EDWIN E. PAGE,
WM BRUNTON. (L.B.)
Camborne, Cornwall.