Improvements in and relating to Expanding Piston Rings for Machinery generally.
Year: 1891

page_text: Date of Application, 27th June, 1891-Accepted, 1st Aug.,
1891
Improvements in and relating to Expanding Piston Rings for
Machinery generally.
We, WILLIAM ARMSTRONG and JOHN WILSON SIMPSON both of Abbey Town
Silloth Carlisle Millwrights, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-
This invention has for its object the providing of expanding rings for use in
pistons, whereby the metallic packing rings in ordinary use, are made automatically
adjustable while working, thereby preventing waste of steam and power, and at the
same time making the metallic packing wear equally at all points, and consequently
much longer.
With this object we construct our expanding piston rings preferably of a band
of steel of any suitable thickness, and of the same width as the metallic packing
rings on the piston in which the same is to be used. On each end of this band of
steel, a brass or other metal casting of the required form and dimensions is firmly
affixed by means of rivets or other convenient method.
On the opposing faces of these castings or blocks any suitable number, but
preferably two, studs or projections are formed for holding a corresponding number
of spiral or other springs in their proper positions, such springs being compressed
while the ring is in its position in the piston, thus exerting an expanding pressure
on the steel band.
For the better illustration of this, our invention, we have hereunto annexed a
sheet of drawings in which,
Fig. represents our invention as it appears before being placed in position on
B, B, are the brass or other
the piston. A is the steel band forming the ring.
castings firmly affixed to the free ends of A by the rivets C, C. D D, the spiral
springs surrounding the studs or projections E. E, E, E, by which they are kept in
position, exerting the required pressure on the opposing faces of the blocks or
castings B B.
Fig. 2 is a plan of a piston having the bottom-plate removed to show the position
Fis the end of the piston rod, G the piston
of the expanding ring when in use.
block showing face for the sunk ring. Hthe expanding piston ring in position
exerting pressure on the metallic packing rings I, and also closing the gap in same
at J thus preventing the escape of steam.
By the use of our invention, the expanding ring being placed inside the ordinary
metallic packing, by exerting outward pressure thereon, causes the same to become
automatically adjustable to any inequalities in the cylinder, thus the piston works
easier, and the packing wears much longer. By being inside, they also close
the gaps in the packing rings thereby saving the waste of steam at those
points.
Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare that what
we claim is:-
The construction and use of expanding rings applied to the metallic packing in
pistons as and for the purposes herein set forth, described, and illustrated.
1
1001
GRAHAM & GRAHAM,
Agents for Applicants.