IMPROVEMENTS IN STEAM AND OTHER PISTONS
Year: 1883

page_text: LETTERS PATENT to Alexander Mac Laine of Belfast in the County of Antrim
in Ireland for an Invention of IMPROVEMENTS IN STEAM AND OTHER PISTONS
PROVISIONAL SPECIFICATION left by the said Alexander Mac Laine at
the Office of the Commissioners of Patents on the 11th August 1883.
ALEXANDER MACLAINE of Belfast in the County of Antrim in Ireland
IMPROVEMENTS IN STEAM AND OTHER PISTONS
My Invention has reference to certain arrangements by which I impart to the
metallic packing rings of Steam and other Pistons a double expansion movement
and for which I have procured the Letters Patent N° 408 and the Provisional
Protection N° 2802 both of the present year 1883 and is especially applicable to
the arrangements comprised in said Provisional Protection.
I modify said arrangements by inserting gun-lock, C or other springs inside the
packing rings above mentioned (and described in my previous specifications) so as to
aid the Coil springs (therein also described) in expanding the packing rings
circumferentially against the inner surface of the cylinder.
I place such springs by preference at or near to the part of the packing ring
which is diametrically opposite the transverse cut and coil spring described in my
previous specifications but I may use a number of such springs extending further
round the packing ring and may dispense with the coil spring altogether and may
place one or more of such gun-lock, C or other springs at each end of the packing
ring where cut through in substitution for the coil spring.

page_text: "
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Alexander Mac Laine in the Patent Office on the 5th February
1884.
ALEXANDER MACLAINE of Belfast in the County of Antrim in Ireland
"IMPROVEMENTS IN STEAM AND OTHER PISTONS
"
My invention has reference to certain arrangements by which I impart to the
metallic packing rings of steam and other pistons a double expansion movement
and for which I have procured the Letters Patent N° 408 and N° 2802 of the said
year one thousand eight hundred and eighty three and the same is especially, but
not exclusively, applicable to the arrangements described in the Final Specification
filed pursuant to the conditions contained in said Letters Patent N° 2802.
I modify said arrangements by inserting Gunlock C. or other short springs inside
the metallic packing rings above mentioned (and described in the specifications
filed pursuant to the conditions contained in the several Letters Patent hereinbefore
referred to) so as to aid the coil springs (therein also described) in expanding the
packing rings circumferentially against-the inner surface of the cylinder.
I place the Gunlock C. or other short springs afore mentioned by preference at
or renr to the-part-of-the-packing ring which is diametrically opposite to the
transverse cut and coil spring described in my previous Final Specifications but I
may use a number or series of such springs extending at intervals further or
entirely round the packing rings and may dispense with the coil spring altogether
or I may place one or more of such springs-at-the-ends of the packing ring where.
cut through in substitution for the coil spring.
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 compound apparatus
throughout all the drawings and figures described in and annexed to this and my
several other Final Specifications herein before mentioned.
Fig. I. 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 Bat
steel springs in the recess formed between the packing rings and confined (on one
side) between the outside and inside flanges and (on the other) between the outside
flauges and the body of the piston on the inside.
Fig. II. is a plan of a piston, partly in section, having the junk ring removed
and shewing (among other parts) a metallic 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 be introduced, if desired, and used to prevent the packing ring
travelling round the piston and a number or series of C. springs placed at intervals
entirely round the packing ring except the portion across which a coil spring
extends.
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

page_text: 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
shown 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 are the coil springs; c c are the bars or tubes
through the coil springs; d d are the pins which secure the coil springs and bar's or
tubes in the grooves or between the jaws formed on the packing rings; e is the
junk ring; fis the body of the piston; gg are the jaws on the packing rings;
hh the steel washers by which the pressure of the coil spring is adjusted; kk the
flat waved or corrugated springs; the doubled over ends of the flat springs ;
mm are the flanges on the outside and inside edges of the packing rings; n. n. are
the blocks cast on the packing rings; oo are the C springs placed at intervals
round the packing ring to aid the coil spring; and p is the pin through the ovalled
hole in the packing ring by which it may if desired be prevented from 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 Gunlock, C. or other similar short springs except when the same
are used in conjunction with double expansion flanged or recessed packing rings
with wave springs between, expanding them in the direction of the longitudinal
axis of the cylinder and are arranged specially and employed in the manner
hereinbefore described nor do I claim the use of any of the separate mechanical
parts which form the compound automatic apparatus employed by me but I claim
1 The use in steam and other pistons of double expansion packing
rings arranged with Gunlock, C. or other similar short springs
constructed and employed substantially in the manner and for the
purposes hereinbefore described and referred to and shewn in Fig. II.
of the drawings hereunto annexed and
2ndly The combination and arrangement of parts constituting the
compound automatic elastic metallic packing ring above mentioned
constructed and applied substantially in the manner and for the
purposes herein before described and referred to and illustrated by the
drawings hereunto and to the herein before mentioned previous Final
Specifications respectively annexed.
In Witness whereof I the said Alexander MacLaine have hereunto set my hand
and seal this first day of February in the year of our Lord one thousand eight
hundred and eighty four.
Signed and Sealed in presence of
ATERRA