IMPROVEMENTS IN STEAM AND OTHER PISTONS
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by the said Alexander Mac Laine at the
Office of the Commissioners of Patents on the 6th June 1883.
ALEXANDER MACLAINE of Belfast in the County of Antrim in Ireland.
IMPROVEMENTS IN STEAM AND OTHER PISTONS
I provide the piston with two or more metallic Packing rings cut through
transversely in one or more places and I impart to such rings a double expansion
movement by means of coil springs placed at or near and across the ends of the
rings in order to press such ends apart in a circumferential direction and by means
of two or more flat springs placed at intervals around the circumference of and
between the packing rings in order to press such rings apart in the direction of the
longitudinal axis of the cylinder; And I provide the inside of the packing rings
with ribs blocks snugs or other projections so arranged that the rings may thereby
receive support from the body of the piston and resist the force of the steam or
water.
I prefer to use only two packing rings each having one transverse cut and being
fitted with a coil spring through which I pass a bar or tube in order to strengthen
it and maintain its position and I arrange the inside of the rings with grooves and
pins or other fastenings by which the coil spring and bar or tube may be
introduced into and secured in position without any material or injurious
expansion of the ring.
I also prefer to enclose the flat springs between the packing rings in recesses
formed by constructing flanges on the outer and inner edges of the packing rings
or I may provide such flange on the outer edge only and employ the body of the
piston to confine the springs on the inner side.
And I may make the ends of the flat springs thick or furnish them with a
bend or angle or otherwise arrange them with a foot or stop to prevent the springs
from shifting

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Alexander Mac Laine in the Great Seal Patent Office on the
4th December 1883.
ALEXANDER MACLAINE of Belfast in the County of Antrim in Ireland
* IMPROVEMENTS IN STEAM AND OTHER PISTONS"
The object of my invention is to provide steam and other pistons with durable
and efficient elastic metallic packings having a double expansion movement by
means of modifications of and additions to the automatic apparatus for which [
have obtained Letters Patent bearing date the twenty fifth day of January in this
present year and numbered 408
I provide the piston with two or more metallic packing rings cut through
transversely in one or more places as described in the specification filed under the
condition in said Letters Patent of the twenty fifth day of January last contained
and I impart to such rings a double expansion movement by means of coil springs
placed at or near and across the ends of the packing rings in order to press
such ends apart and expand the rings in a circumferential direction as in said
specification also mentioned and by means of two or more flat springs placed at
intervals around the circumference of and between the packing rings in order to
press such rings apart in the direction of the longitudinal axis of the Cylinder;
and I construct the packing rings with ribs blocks, snugs or other projections cast
in them arranged so as to receive support from the body of the piston and resist
the force of the steam or water drawing them inwards
I use only two packing rings each having one transverse cut and being fitted
with a coil spring as above mentioned. Through the Coil spring I pass a bar or
tute in order to strengthen it and maintain it in position and I arrange the inside
of the packing rings with grooves or jaws by which the coil spring and bar or tube
may be introduced from the inside and placed in position without any material or
injurious expansion of the ring and I secure them in such position by means of
pins or other fastenings
The pressure of the coil spring is by preference adjusted by the use of a steel
washer of requisite thickness at each end of the spring
I also employ in order to press the packing rings apart in the direction of the
longitudinal axis of the cylinder, two or more flat steel springs having two or more
waves or corrugations in each spring and being placed at intervals round the
circumference of and between the packing rings and cuclosed within recesses
formed on the contiguous surfaces of the packing rings by constructing flanges on
the outside and inside edges of the rings or I may provide such flange on the
outside edge of the ring only and employ the body of the piston to confine the
springs on the inner side. And I thicken or double over the ends of the flat
springs or I furnish them with a bend or angle or otherwise arrange them with a
foot or stop approximating to the width and depth of the recess to prevent such
springs from slipping or shifting
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 corr sponding parts of any compound apparatus
throughout all the figures.
Fig 1 is a sectional elevation of a piston shewing, among other parts, the flanged
packing rings with blocks cast in them the coil springs with bars or tubes, the that
steel springs in the recess formed between the packing rings and confued (on one
side) between the outside and inside flanges and, (on the other) between the
outside flanges and the body of the piston on the inside
Fig II is a plan of a piston having the junk ring removed and shewing, among

page_text: other parts, a packing ring with blocks cast in it the coil spring with a bar or tube
through it, steel washers jaws and securing pins, and a pin which may if desired
be introduced and used to prevent the packing ring travelling round the piston
Fig III is an enlarged detail of Fig I shewing the packing rings with blocks, the
junk ring and the wave spring confined in the recess between the outside flanges
and the body of the piston
.
Fig IV is also an enlarged detail of Fig I shewing the packing rings with blocks,
the securing pin, the coil spring and bar and the wave spring confined in the recess
between the outside and inside flanges of the packing rings
Fig V is an enlarged detail of Fig II shewing the position and application of
the pin which may be introduced to prevent the packing ring travelling round the
piston
Fig VI is also an enlarged detail of Fig II shewing a packing ring with jaws for
receiving the coil spring and bar or tube and the pins for securing them in the
jaws, the coil spring with a bar or tube through it and the steel washers to adjust
the pressure of the coil spring; and
Fig VII is an enlarged sectional detail shewing, in elevation, the same parts as
shewn in Fig VI and also the flat steel waved or corrugated springs with doubled
over ends in the recess formed between the packing rings
a. a. are the packing rings; b. b. the coil springs; c. c. the bars or tubes through
the coil springs; d. d. the pins which secure the coil springs and bars or tubes in
the grooves or between the jaws formed on the packing rings; e is the junk ring;
f the body of the piston; g. g. are the jaws on the packing rings; h. h. the steel
washers by which the pressure of the coil spring is adjusted; k. k. the flat waved
or corrugated springs; l. l. the doubled over ends of the flat springs; m. m. the
flanges on the outside and inside edges of the packing rings; n. n. the blocks cast
on the packing rings; and p is the pin through the ovalled hole in the packing
ring which prevents it travelling round the piston
Having now described the nature of my said invention and in what manner the
same is to be performed I would have it to be understood that I do not claim the
exclusive use of transversely cut and flanged or recessed packing rings with grooves
or jaws, flat springs with waves or corrugations and doubled over ends, bends,
angles or feet, coil springs with bars or tubes through them, junk rings and steel
washers except when the same are constructed and arranged specially and employed
in the manner hereinbefore described, nor do I claim the use of pistons or cylinders
nor of any of the separate mechanical parts which form the compound automatic
apparatus employed by me but I claim"
First The use in steam and other pistons of double expansion packing rings
arranged with coil springs and bars or tubes introduced from the inside
and secured in grooves or jaws, and constructed and employed substan-
tially in the manner and for the purposes herein before described and
shewn in Figs I. III. IV and VII
Secondly The use in steam and other pistons of double expansion packing rings
arranged with a flange or flanges for confining the springs and constructed
and employed substantially in the manner and for the purposes herein-
before described and shewn in Figs I. III. IV and VII of the drawings
hereunto annexed.
Thirdly The use in steam and other pistons of double expansion packing rings
arranged with ribs, blocks, snugs or other projections and constructed
and employed substantially in the manner and for the purposes herein-
before described and shewn in Figs I. II. III and IV of the drawings
hereunto annexed
Fourthly The use in steam and other pistons of flat steel springs having waves
or corrugations and arranged with doubled over ends, bends, angles feet
or stops and enclosed or confined between the packing rings substantially
in the manner and for the purposes herein before described and shewn in
Figs 1. III, IV and VII of the drawings hereunto annexed and

page_text: Fifthly The combination and arrangement of parts constituting the compound
automatic elastic packings above mentioned, constructed and applied
substantially in the manner and for the purposes herein before described
and illustrated by the drawings in Figures I. II. III. IV. VI and VII on
the sheet hereunto annexed
In Witness whereof I the said Alexander MacLaine have hereunto set my band
and seal this First day of December in the year of our Lord One thousand eight
hundred and eighty three
Signed and Sealed
in presence of
WILLIAM MARK CRAIG
Clerk to Hyndman & Dickson
Belfast Solicitors
ALEXANDER MACLAINE (L.S.)