IMPROVEMENTS IN METALLIC PACKING FOR PISTON VALVES to be as follows:
Year: 1884

page_text: I ALEXANDER MACLAINE of N° 1 Queens Elms, Belfast, in the County of Antrim,
ship owner do hereby declare the nature of my invention for "IMPROVEMENTS IN
METALLIC PACKING FOR PISTON VALVES to be as follows:-
"
I construct Piston Valves for steam engines with one or more packing rings each
cut through transversely in one place and each fitted with one or more coil springs
at the ends where cut through arranged to press the ends apart and expand the
packing ring circumferentially outwards-I fit each of said coil springs with a bar
or tube passing through it arranged so that the bar or tube and the coil spring can
be introduced into its place from the inside of the packing ring and made secure
with jaws and pins or other fastenings without material or injurious expansion of the
packing ring, and I may construct said packing rings with internal blocks, snubs,
or projections cast in them arranged to receive support from the piston valve body
and prevent the packing rings being injuriously driven inwards by the force of
steam or water; and I may introduce auxiliary coil or other springs between the
packing rings and the piston valve body to aid the coil springs in the circumferential
outward expansion of the packing rings.

page_text: I ALEXANDER MACLAINE of No 1 Queens Elms, Belfast, in the County of Antrim,
Shipowner, do hereby declare the nature of my invention for IMPROVEMENTS IN
METALLIC PACKING FOR PISTON VALVES and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:-
I construct the packing rings for Piston Valves each cut through transversely in
one place and fitted with one or more main coil spring or springs placed at or near
and across the ends where cut through and arranged to press the ends apart and
thus to expand the packing ring circumferentially outward; I strengthen each main
coil spring by passing a bar or tube longitudinally through it and I form a longitu-
dinal hollow or recess in the packing ring internally at each extremity, in order
that the main coil spring and its enclosed bar or tube may be introduced into
position from the inside without any material or injurious expansion of the packing
ring and I secure the main coil spring and bar or tube in position by means of
jaws and pins or other fastenings.
The thrust of the main coil spring is by preference regulated by the thickness of
a steel washer interposed between each end of such spring and the packing ring.
I also construct the packing ring with a number of internal blocks snugs or
projections cast in it so that the packing ring may receive support from the piston
valve body, and be prevented from being injuriously driven inwards by the force of
steam or water, and I may sometimes, but not necessarily, aid the main coil springs
in circumferentially expanding the packing ring outwards, by the use of auxiliary
coil or other springs introduced between the packing ring and the piston valve body
and placed in some or all of the interstices between the internal blocks snugs or
projections.
And in order that my said invention may be more fully understood I shall now
proceed to refer to the drawings upon the sheet hereunto annexed, the same letters
of reference indicating the same or corresponding parts of my packing ring
throughout all the figures.
Fig I is the plan of a packing ring for a piston valve, shewing the ring cut
through transversely in one place and fitted with a main coil spring and bar or tube
across the ends where cut through; also shewing internal blocks, and an auxiliary
coil spring placed in one of the interstices between the blocks.
Fig II is a transverse section of a portion of the body of a piston valve shewing
the packing ring and main coil spring in position.
Fig III is a sectional elevation of the face of the packing ring shewing the cut in
the ring.
Fig IV is a plan of a steel washer for receiving the thrust of the main coil
spring.
a is the cut in the ring, b is the main coil spring across the cut arranged to press
the ends of the packing ring apart and expand it circumferentially outwards, c is a
bar or tube passing through the main coil spring; d d are the jaws between which
the main coil spring and bar or tube are inserted from the inside of the packing
ring, and e e are the pins by which the same parts are secured in position; ffare

page_text: the steel washers for receiving the thrust of the main coil spring; 999 are the
internal blocks cast in the packing ring to impart to it support from the body of
the piston valve h and prevent it being driven inwards by steam or water; k is
one of the auxiliary coil springs which may be introduced into the interstices n n
for the purpose of aiding the main coil spring in the outward circumferential
expansion of the packing ring; 11 are brass tongue pieces to tighten and cover
the cut in the packing ring, and m is a steady pin to prevent the ring travelling
round.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is
First The use in steam engine Piston Valves of a packing ring fitted with a
longitudinal coil spring and bar or tube (or coil springs and bars or tubes) for
outward expansion substantially as described and shewn Figs I and II of the
drawings hereunto annexed.
Second-The use in steam engine Piston Valves of a packing arranged with
internal blocks or projections cast in it, and intervening auxiliary coil springs
together with a longitudinal coil spring and bar or tube constructed and employed
substantially in the manner and for the purposes herein before described and shewn
in Fig I of the drawings hereunto annexed; and Third-The combination and
arrangement of parts constituting the metallic expanding packing ring above
mentioned, constructed and applied substantially in the manner and for the
purposes herein before described and illustrated by the drawings hereunto annexed.
Dated this seventh day of February 1885.