Improvements in the Construction of Pistons for Steam and other Engines and Pumps.
Year: 1897

page_text: Date of Application, 21st July, 1897-Accepted, 21st Aug., 1897
COMPLETE SPECIFICATION.
Improvements in the Construction of Pistons for Steam and other
Engines and Pumps.
We JOHN DERBYSHIRE and REUBEN DERBYSHIRE of Hall Cottage Longton, in the
County of Stafford, Engineers, 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 improvements in the construction of pistons for
steam and other engines, and pumps.
For this purpose, two metallic rings are made for each piston, by preference of
cast iron. They are made eccentric in form to vary in width and thickness as
various sized cylinders may require, the rings to fit each other either parallel or
cone shaped, the outside of the inner ring, to be the size of the inside of the outer
ring. When put together the thin part of one ring must adjoin the thick part of
the other ring, so that they will be of equal thickness at any point the rings are
cut through in the thin part of each, and such a portion taken out of each as may
be suitable or necessary to give the spring or reflex to properly fit the cylinder, the
taper rings will tend to take up any possible wear between the flanges of the
piston; the inner ring may be cut square across, but the outer ring cut at an angle.
In the thick part of the inner ring a tongue, or tongues, is fixed to form a stop for
steam, or water, and keep the rings in their relative positions, the outer ring being
slotted to fit upon the tongue. These rings will suit for steam pistons air pumps,
or water pumps, the rings will not crinkle but be a true circle under compression,
they may be blocked in the piston, or compressed by a band so as to be put in the
cylinder, rings so made will retain their elastic force for years; when the outer
ring is worn through, the inner ring will still be of use.
Fig. 1. A plan of rings before compression.
Fig. 2. A side view, showing angle cut, and tongue.
Fig. 3. A section of rings, the inner joint open.
Fig. 4. A plan of rings compressed.
Fig. 5. A side view compressed, angle cut, and tongue.
Fig. 6. A section of rings compressed, the inner joint close.
Figs. 7 and 8. Section of taper rings and tongue, open and close.
Figs. 9 and 10. Section of parallel rings and tongue, open and close.
Having now particularly described and ascertained the nature of this our
invention and in what manner the same is to be performed, we declare that what
we claim is:-
The making of two metallic rings for each piston or bucket, preferably of cast
iron, eccentric in form; the rings to be fitted together, either parallel or taper, the
thin part of one ring to the thick part of the other ring, each ring cut, and a portion
taken out of the thinnest part of each, a tongue or tongues let in the thick part of
the inner ring to make a tight joint, and keep the rings in their relative positions.

page_text: they are compressed to the proper size and put in the piston or cylinder,
substantially as described and shown by the drawings.
1411
T.1007
JOHN DERBYSHIRE.
REUBEN DERBYSHIRE.