Improvements in and relating to Piston Packing Rings.
Year: 1888

page_text: Date of Application, 15th Nov., 1888
Complete Specification Left, 13th Aug., 1889-Accepted, 14th Sept., 1889
PROVISIONAL SPECIFICATION.
Improvements in and relating to Piston Packing Rings.
I, JAMES MENZIES, of 52 Mount Street, Glasgow, Lanarkshire, Engineer, do
hereby declare the nature of my Invention to be as follows :-
This Invention has reference to and comprises improvements in spring packing
rings of pistons for motive power cylinders and other purposes, and which will be
more simple in construction and efficient in action than those heretofore in use,
enabling the tension on the spring rings to be adjusted as required.
while
According to my invention I use a series of segmental helical springs preferably
of the eliptical or flat form, fitted in sections round the periphery of the piston
within the usual two sets of packing rings. By my improvements I form at the ends
of each of the sections of holical springs a wedge piece or pin with a stem fitting
within the coil of the spring, and having a head projecting out at each end of spring,
said head being formed of a duplex dovetail, rounded, or other equivalent shape, to
fit into corresponding shaped grooves or recesses in double blocks or projecting parts
secured to or formed on the inner surface of the periphery of the packing rings at
suitable distances apart opposite each other, as also having the springs acting between
the joints where these are cut. This arrangement would make the pressure of the
springs to act when the usual junk ring is screwed down, in the longitudinal or
reciprocating line of the piston, to press the two sets of rings against the junk ring
and inner turned flange of the piston, and without unduly compressing them against
the inside of the cylinder in which the piston is fitted, so as to avoid needless wear on
the cylinder. When the tension of any of the helical spring sections gets diminished,
these sections can be lengthened and tightened up or compressed by placing washers
round the stems of tho pressing heads between these and the springs, or by sub-
stituting longer projecting heads within their ends to bear against the projecting
parts formed on the inside surfaces of the rings round the periphery of the piston.
Dated this 11th November 1888.
W. R. M. THOMSON & Co.,
Agents.
COMPLETE SPECIFICATION.
Improvements in and relating to Piston Packing Rings.
I, JAMES MENZIES, of 52 Mount Street, Glasgow, Lanarkshire Engineer, do hereby
declare the nature of my said invention, and in what manner the same is to be
performed to be particluarly described and ascertained in and by the following
statement in writing, reference being had to the accompanying Sheet of Drawings,
and to the letters and figures marked thereon, that is to say :-
This Invention has reference to and comprises improvements in spring packing
rings of pistons for motive power cylinders and other purposes, and which will be
more simple in construction and efficient in action than those heretofore in use, while
enabling the tension on the spring rings to be adjusted as required.
And in order that my said invention and the manner of performing or carrying
the same into effect or practice may be properly understood, I have hereunto appended
an explanatory Sheet of Drawings, in which the same reference letters are used to
indicate corresponding parts in all the figures where shown. Figures 1 and 2 are a
transverse section and a plan of the two rings of piston, the former taken on the
line 11 of the latter, and constructed in accordance with one arrangement of my
improvements. Figures 3 and 4 are a corresponding internal section and plan of

page_text: the joint part A' of the rings A A to an enlarged scale, showing a slight modifi-
cation from that shown in Figures 1 and 2. Figure shows an edge and side view
of one of the springs a detached, and Figure 6 a corresponding edge and side view
of one of the pressing stem heads or pins 6, 61, for inserting into the ends of the
springs a and acting on the angled surfaces A¹ of the rings A and pressing these
out against the flange A and junk ring of the piston, both of these Figures being
drawn to a large scale corresponding to Figures 3 and 4.
Referring to theso Drawings, according to my invention I use a series of segmental
helical springs a preferably of the eliptical or flat form, fitted in sections round the
periphery of the piston within the usual two sets of packing rings A. A. By my
improvements I fit within the ends of each of the sections of helical springs a a wedge
piece or pressing head with a stem & fitted within each end of the spring a and
having the head projecting out at each end of spring, said head being formed of
a duplex bevelled shape on its outer end preferably rounded in plan to fit into
corresponding shaped reverse angled grooves or recesses A³, in projecting parts A",
formed on the inner surface of the periphery of the packing rings A at suitable
distances apart opposite each other, as also having the springs a acting between the
joints at A, where these are cut, and where the usual brass or other plates A³ are
fitted on the faces. This arrangement makes the pressure of the springs a to act
when the usual junk ring is screwed down, in the longitudinal or reciprocating line
of the piston, to press the two sets of rings A A, against the inner turned flange of
the piston and its junk ring to maintain tight joints between these, and also to press
the rings out circumferentially against the working surface of the cylinder, sufficient
to keep them tight, without undue wear on the cylinder. When the tension of any
of the helical spring sections a gets diminished, as say the one a¹ fitted in the space
where the joints A³ are formed in the rings A, these spring sections a can be
lengthened and tightened up or compressed by placing a washer or washers a² of
any required thickness round the stems 6' of the pressing heads 6 between these and
the springs a, or by substituting longer projecting heads b within their ends to bear
against the angled grooves A of the projecting parts A" formed on the inside
surfaces of the rings A round their inner periphery, and so expand the rings A to any
desired circumferential distance and pressure of resilience of spring, and any
desired pressure of the rings outwards from each other.
Referring to the modification shown in Figures 3 and 4 which is particularly
applicable for the pistons of high pressure cylinders, this shows the application and
use of a segmental clip or clamp plate C C4, inserted in a recess in the two
rings AA, at their joint parts A' inside the spring a with clip heads C¹, having
sufficient play at the projections c of the heads in their recesses to allow the rings A
to be sprung out circumferentially to any desired distance as shown particularly in
Figure 8 where the spring a is removed for that purpose, but in case of neglect on
the part of the attendant to the adjustment, would prevent them from springing
further, and also to prevent undue wear of the rings and the working surface of the
cylinder within; and these projections c on the heads C¹ could be filed or reduced
from time to time to adjust the wear and expansion desired.
For gas engine pistons, which are only single acting, and in which only one
expanding ring is usually employed, I would make the acting angle on the ends of
the pressing out stem heads bb' straight, and all in one direction, acting on similar
reverse angled grooves A' on the projections A" of the ring A, so that as the junk
ring screwed this up, or the pressure came upon the junk ring, it would ensure
tightness of the ring on the outer joint, and on the working-surface of the cylinder.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
First. The construction, or arrangement and combination of the parts of piston
packing rings fitted with a series of segmental helical springs, with pressing out
blocks and fittings at their abutting ends, and acting laterally and circumferentially

page_text: on the rings, substantially as and for the purposes herein described in reference to
and shown in the accompanying Drawings.
Second. In piston spring packing rings, the fitting of duplex angled or wedge
pressing out blocks or pins at the ends of each or any of the sections of helical springs,
the steins of the blocks fitting within the coils of the springs, and the duplex angled
heads acting against corresponding angled grooves or projections on the inner
surface of the packing rings, all substantially as and for the purposes herein described,
in reference to and shown in the accompanying Drawings.
W. R. M. THOMSON & Co.,
96, Buchanan Street, Glasgow, Agents.