Improvements in Pistons for Steam, Hydraulic, Gas, or Air Engines.
Year: 1889

page_text: Date of Application, 14th Feb., 1889
Specification Accepted, 16th Mar, 1889
Improvements in Pistons for Steam, Hydraulic, Gas, or Air
Engines.
We CHARLES THOMAS DAVENPORT and EDWARD JOHN HORSLEY both of Elworth
Sandbach in the County of Chester 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 relates to improvements upon the construction of pistons for
which Letters Patent were granted to the said Edward John Horsley dated
3rd day of December 1886 No. 15799 the objects of the present invention being to
simplify and economize the construction of such pistons and to reduce the number
and weight of the parts employed.
The nature of our said invention and the manner in which the same is to be
performed or carried into practical effect will be readily understood on reference to
the Sheet of drawings hereunto annexed and the following explanation thereof.
Fig. 1. is a sectional view (shown partly in elevation) of a piston and packing
constructed according to our invention and Fig. 2. is a plan view of the same.
a represents the end of the piston rod, & the block or body of the piston which we
make lighter and more open than heretofore and c the junk-ring. d is the centre piece
which we make with a double inclined plane as before. We dispense with the sliding
plates (marked A, on the drawings of Specification No. 15,799 before referred to)
using only the packing rings e and for the purpose of causing the steam (water, gas,
or air as the case may be) to act directly against the faces of such packing rings so as
to cause them to be expanded by pressure against the double inclined centre piece d
we reduce the external diameter of the junk ring c and of the corresponding flange b
of the block b so that the steam water, gas, or air has free access to the external
face of each packing ring e so as to force them against the inclined surface of the centre
piece d.
And in order to keep the joint of the ends of the said rings e steam water, gas, or
air tight we remove the "bit" from the outside of the ring where it is usually placed,
and we apply the same to the inner edge thereof as shown on the drawings whereby
echioin a nerfactly tight joint.

page_text: Having now particularly described and ascertained the nature of our said Inven-
tion and in what manner the same is to be performed we declare that what
we claim is :-
First the improved construction of pistons for steam, hydraulic, gas, or air engines
substantially as hereinbefore described and illustrated by the drawings annexed.
Secondly we claim the combination in pistons of the two packing rings, the centre
piece with double inclined plane, and the reduction of the diameter of the junk ring
and the flange of the block or body so that the steam, water, gas, or air shall have
direct access to the external face of the said rings substantially in the manner and for
the purpose herein before particularly set forth, and
Thirdly we claim the removal of the "bits" or "stop pieces," from the external face
to the internal face of the packing rings for the purpose described.
GEORGE DAVIES,
4, St. Ann's Square, Manchester,
Agent for the Applicants.