Improvements in Metallic Piston-packing.
Year: 1891

page_text: Date of Application, 24th Dec., 1891
Complete Specification Left, 24th Sept., 1892-Accepted, 3rd Dec., 1892
PROVISIONAL SPECIFICATION.
Improvements in Metallic Piston-packing.
We SYDNEY ASLINE WARD Tudor Place, Sheffield, in the County of York,
Engineer, and WILLIAM ROADHOUSE, Norfolk Park, Engineer, both of Sheffield
in the County of York do hereby declare the nature of my invention to be as
follows
:-
This invention of improvements in the metallic packing of pistons has for its object.
to produce a compensating and yet a practically solid piston.
We propose therefore to construct a piston as follows; between the block face
and cover faces of the piston which are held apart in the usual manner by the piston
block, we fit two cut rings one being wider than the other, say for example in the
proportions of 2 or 3 to 1.
The outer edges of both rings are square to fit against the faces of the block
and cover, but their adjacent or inner edges are bevilled and fit together in such a
manner that when the main ring is expanded it rises up the inclined face of the.
narrow ring, or otherwise it causes the narrow ring to expand.
This movement of the ring on its inclined face or edge applies the vertical pressure.
against the block and cover faces.
To cause the main ring to expand we use a compensating resisting coil of flat
steel or other suitable metal, coiled upon itself in any required number of coils.
The object of this coiled resistance is to expand the main ring alone with the.
requisite force, but on account of the frictional contact between the various coils,.
compression is practically impossible, and thus we construct a practically solid
piston.
The breadth of the metallic coil before mentioned corresponds with the width of
the main ring, and does not act against the narrow ring, which if desirable may be
extended towards the interior for the coil to rest upon.
Dated the 23rd day of December 1891.
ROBT. F. DRURY, C.P.A.,
Bank Buildings, George Street, Sheffield, Agent for Applicants.
COMPLETE SPECIFICATION.
Improvements in Metallic Piston-packing.
We SYDNEY ASLINE WARD, Tudor Place, Sheffield in the County of York,.
Engineer, and WILLIAM ROADHOUSE, of Heeley Sheffield aforesaid, Engineer,
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 of improvements in the metallic packing of pistons has for its
object to produce a compensating action in what is practically a solid piston.
The annexed sheet of drawings shows the piston packing in perspective, with the
rings held apart to show the bevilled faces.
The packing is held in the usual manner between the inner faces of the piston
block and the cover.
>
It consists of two metal rings, A. and B, preferably made of cast iron, the
lower ring marked B, being of greater width than A, in the proportion, for
example of two to one, or thereabouts, and each ring is provided with a glut or
stopping piece C.

page_text: The outer edges of each ring are square to fit against the face of the block and
the cover, and their inner or adjacent edges are bevilled as seen and fit upon one
another.
The spring D, is made of flat steel, coiled upon itself in any required number of
coils but usually two or three coils are sufficient for the purpose, and we prefer to
make it of steel of sufficient hardness as not to require hardening, in which operation
springs are often cracked, or otherwise injured.
This spring is made of the same width as the broader ring B, so as not to
act upon the narrow ring A, the object of the coiled spring being to expand the
broad ring with the requisite force to compensate for the wear, but owing to the
frictional contact of the several coils upon each other, compression of the spring is
practically impossible.
The smaller ring A, is expanded by the pressure upon the bevilled faces or
edges before mentioned, when the main ring B, is expanded, and this action of the
inclined faces also applies the vertical pressure between the faces of the block
and cover.
Having now particularly described and ascertained the nature of our invention
and the manner in which the same may be carried into practice, we declare that
what we claim is :-
1-A metallic piston-packing consisting of a broad ring B, and a narrow ring A,
having their adjacent edges bevilled, and in contact, in combination with a flat coiled
spring of two or more coils D, acting only against the broad ring B for the purpose
specified, substantially as hereinbefore described, and with reference to the annexed
drawings.
2-A metallic piston packing consisting of two cut rings having their adjacent
edges bevelled, in combination with a closely coiled spring of flat steel acting
against the inner periphery of one of the rings substantially as hereinbefore described
and shown.
Dated the 23rd day of September 1892.
ROBT. F. DRURY, C.P.A.,
Bank Buildings, George Street, Sheffield, Agent for Applicants.