IMPROVEMENTS IN METALLIC PACKINGS FOR PISTONS
Year: 1856

page_text: LETTERS PATENT to Robert Sam North, of Derby, in the County of
Derby, Engineer, and Ralph Peacock, of New Holland, in, the County
of Lincoln, Engineer, for the Invention of "IMPROVEMENTS IN METALLIC
PACKINGS FOR PISTONS."
PROVISIONAL SPECIFICATION left by the said Robert Sam North and
Ralph Peacock, at the Office of the Commissioners of Patents, with
their Petition, on the 4th January 1856.
We, ROBERT SAM NORTH, of Derby, in the County of Derby, Engineer, and
RALPH PEACOCK, of New Holland, in the County of Lincoln, Engineer, do
hereby declare the nature of the Invention for "IMPROVEMENTS IN METALLIC
PACKINGS FOR PISTONS" to be as follows:-
This Invention has for its object improvements in the construction and
combination of flat spiral springs and metallic rings used for packing pistons.
In the groove or space around the body of the piston, and between its uppor
and lower plates, a flat spiral spring the width of the packing space is fixed,
clipping the body of the piston, and on this flat spiral spring are placed three
metallic rings to form the packing, such rings having a tendency to expand in
diameter when permitted so to do. The first or chief ring is by preference
formed flat on its inner surface, with a rib or projection on its outer surface.
This ring fits into the groove or packing space of the piston around the flat

page_text: spiral spring, and the rib or projection on its outer surface comes against the
cylinder in which the piston works. The two other rings are flat on both
the inner and outer surfaces, and are respectively placed on the two sides of
the rib or projection on the first or chief ring, and they come flush with the
outer surface of the rib or projection on the first or chief ring, and thus their
outer surfaces and the outer surface of the rib or projection constitute the
wearing surfaces of the metallic packing. Each of the rings is cut across or
open at one part of its circumference, and these cuts or openings when tho
packing is put together are to be at a distance from each other, which is
called "breaking joint;" although the use of three rings is preferred, as above
explained, their number may be varied.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Robert Sam North and Ralph Peacock in the Great Seal
Patent Office on the 4th July 1856.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, ROBERT
SAM NORTHI, of Derby, in the County of Derby, Engineer, and RALPII PEACOCK,
of New Holland, in the County of Lincoln, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fourth day of January, in the year of our Lord
One thousand eight hundred and fifty-six, in the nineteenth year of Her reign,
did, for Herself, Her heirs and successors, givo and grant unto us, the said
Robert Sam North and Ralph Peacock, Her special licence that we, the
said Robert Sam North and Ralph Peacock, our executors, administrators, and
assigns, or such others as we, the said Robert Sam North and Ralph Peacock,
our 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 "IMPROVEMENTS IN METALLIC PACK-
INGS FOR PISTONS," upon the condition (amongst others) that we, the said
Robert Sam North and Ralph Peacock, our executors or administrators, by
an instrument in writing under our or their hands and seals, or under the
hand and seal of one of us or them, should particularly describe and ascer-
tain 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

page_text: within six calendar months next and immediately after the date of the said
Letters Patent.
NOW KNOW YE, that we, the said Robert Sam North and Ralph
Peacock do hereby declare the nature of the said Invention, and in what
manner the same is to be performed, to be particularly described and ascer
tained in and by the following statement thereof, that is to say :-
:
This Invention has for its object improvements in the construction and
combination of flat spiral springs and metallic rings used for packing pistons.
In the groove or space around the body of the piston, and between its upper
and lower plates, a flat spiral spring the width of the packing space is fixed,
clipping the body of the piston, and on this flat spiral spring are placed three
metallic rings to form the packing, such rings having a tendency to expand in
diameter when permitted so to do. The first or chief ring is by preference
formed flat on its inner surface, with a rib or projection on its outer surface.
This ring fits into the groove or packing space of the piston around the flat
spiral spring, and the rib or projection on its outer surface comes against the
cylinder in which the piston works. The two other rings are flat on both
the inner and outer surfaces, and are respectively placed on the two sides of
the rib or projection on the first or chief ring, and they come flush with the
outer surface of the rib or projection on the first or chief ring, and thus their
outer surfaces and the outer surface of the rib or projection constitute the
wearing surfaces of the metallic packing. Each of the rings is cut across or
open at one part of its circumference, and these cuts or openings when the
packing is put together are to be at a distance from each other, which is
called "breaking joint;" although the use of three rings is preferred, as above
explained, their number may be varied.
These our said improvements will be more clearly understood by reference
to the accompanying Drawings, in which the same letters of reference repre-
sent the same parts in all the Figures.
Figures 1 and 2 are sections of a piston, shewing the body of the piston,
piston rod, spring, and rings. A is the body; B, the rod; C, the spring; D,
the first or chief ring; and E, the smaller rings. It will be seen that the
smallest diameter of the spring clips the body of the piston, and the largest
diameter of the spring presses against the inside of the first or chief ring,
thereby giving an equal pressure all round the packing. In adapting this
packing to existing pistons of the ordinary form, wo shrink a ring on the four
lugs, as shewn in Figure 3. On this ring is placed the spring, clipping the
body of the piston with its smallest diameter. The rings are then placed on
the largest diameter of the spring. The spring and rings should be the same

page_text: width as the packing. space. Figure 4 is a section of the packing where four
small rings are used in conjunction with the first or chief ring..
Having thus described the nature of our said Invention, we would have
it understood that we do not confine ourselves to the exact details described;
but what we claim is,―
Firstly, the use of a spring coiled round the body of the piston, and pressing
on the rings; in the manner shown and described.
Secondly, the use of. a flanged ring D in combination with smaller rings E;
which rest on its flange, as shown and described.
In witness whereof, we, the said Robert Sam North and Ralph Peacock,
have hereunto set our hands and seals, this Second day of July, in the
year of our Lord One thousand eight hundred and fifty-six.
NADE
RALPH PEACOCK.
(L.S.)
Witness to the signing and scaling hereof
.by the said Robert Sam North,.
ROBERT THULROW,
Park Street, Derby.
Witness to the signing and scaling hereof
by the said Ralph Peacock,..
JOSHUA SWAINE SWITHINBANK, Agent,
Great Grimsby.