CERTAIN IMPROVEMENTS IN METALLIC PISTONS
Year: 1866

page_text: LETTERS PATENT to John Booth, of Reddish, in the County of Lancaster,
Mechanic, for the Invention of "CERTAIN IMPROVEMENTS IN METALLIC
PISTONS."
Sealed the 1st March 1867, in pursuance of an Order of the Lord Chancellor,
and dated the 24th August 1866.
PROVISIONAL SPECIFICATION left by the said John Booth at the Office
of the Commissioners of Patents, with bis Petition, on the 24th August
1866.
I, JOHN ВоотH, of Reddish, in the County of Lancaster, Mechanic, do
hereby declare the nature of the said Invention for "CERTAIN IMPROVEMENTS
IN METALLIC PISTONS," to be as follows:-
My Invention is designed for the purpose of maintaining a steam-tight con-
tact between the packing rings of pistons and the interior surface of the
cylinders within which they move, and consists in the use and application of a
peculiarly constructed ring or rings which is formed so as to become elastic
and slightly compressible and from its peculiar form and being compressed it

page_text: has a constant tendency to press outwards against the internal surface of the
cylinder, and thus a steam-tight contact is effected between the surfaces.
The said ring is to be cut or made from a ring of metal or wood of somewhat
larger diameter than the interior of the cylinder so that when formed into an
elastic ring and compressed it will expand against the surface of the cylinder;
the shape into which the ring is to be cut is represented by the following
diagram
In the diagram it will be seen that the solid ring or "blank" is cut nearly
through in the direction of line a, b, the part c being left as the only con-
nection between the top and bottom parts; the spaces d, e, are then made by
cutting diagonally through each half to the line a, b, and running a portion
from the end of each half. When thus formed the original diameter of the
ring may be reduced by compression the ring being made elastic and one or
more of them may be applied to the piston block as required. I would also
remark that a spiral spring may be applied to the ends of the ring to assist in
expanding them.
SPECIFICATION filed in pursuance of the conditions of the Letters Patent,
and of an Order of the Lord Chancellor, by the said John Booth, in the
Great Seal Patent Office on the 2nd March 1867.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
BOOTH, of Reddish, in the County of Lancaster, Mechanic, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-fourth day of August, in the year of our
Lord One thousand eight hundred and sixty-six, in the twenty-ninth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said John Booth, Her special licence that I, the said John Booth, my exe-
.cutors, administrators, and assigns, or such others as I, the said John Booth,
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

page_text: vend, within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "CERTAIN IMPROVEMENTS IN METALLIC
PISTONS," upon the condition (amongst others) that I, the said John Booth,
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 Booth, 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:-
This Invention relates to metallic pistons, and consists of a metallic ring
formed of one piece of metal divided in the centre or other part of its depth by
two cuts, one inclining from left to right from the upper surface downwards
and the other inclining from right to left from the under surface upwards;
both of these diagonal or inclined cuts extend to the centre of the depth of the
ring, one cut is then made round and entirely through the thickness of the
ring horizontally from the bottom of one diagonal cut to the top of the other
leaving a portion of the ring for about the width of half its depth entire. The
ring thus cut may now have its upper and lower or self coupled halves or
sections expanded so as to give the required amount of elasticity thereto when
it may be placed in position in the piston block. By this mode of forming
the ring an equal amount of expansion is obtained on all sides and the friction
is reduced. The said ring is also free to turn as the piston works from end
to end of the cylinder and thus prevents the "fluting" which often results
from the use of ordinary packing rings.
The accompanying Drawing shews the mode of forming the ring for the
practical application of my said improvements.
EXPLANATION OF THE DRAWING.
Fig. 1 is a side view of the said improved ring, and shews the mode of dividing
it; Fig. 2 shews the same ring in plan.
a is the right hand diagonal cut downwards to the centre of the ring from
the upper surface; 6 is the left hand similar cut upwards from the under
surface; c is the portion of the ring which is left entire; d, d, is the horizontal

page_text: I claim metal rings cut and formed as herein described, or in any manner
analagous thereto by varying the depths and directions of the cuts for a
metallic spring packing for steam engine and other pistons.
In witness whereof, I, the said John.Booth, have hereunto set my hand
and seal, this Second day of March, in the year of our Lord One
thousand eight hundred and sixty-seven.