Improvements in and relating to Piston Packing Rings.
Year: 1891

page_text: Date of Application, 5th Mar., 1891
Complete Specification Left, 3rd Dec., 1891-Accepted, 9th Jan., 1892
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 improvements in and relating to the spring
packing rings of pistons for motive power cylinders and other purposes, and
comprises a new mode of and construction of side or tongue plates for fitting on to
the spring rings at the joints where these are cut next the junk ring and rim of the
piston where the steam or pressure-fluid most easily enters to pass into the piston ;
and which will render these joints more perfectly steam or fluid-tight than
heretofore.
The
The improvements consist in forming each of these tongue plates into and over
the cut joints of the piston rings of a parallel thickness and less than the width of
the piston ring with inner tongue end projections fitting into corresponding parallel
grooves of the same depth as the thickness of these plates, leaving a thickness of
the ring inside each plate, the parallel tongue parts preferably having semicircular
ends, and these plates may be fixed by a countersunk headed screw in one of the
rings, and in that case the projection or tongue at that end need not be so long as
in the groove in the spring end of the ring which moves on the tongue plate.
ride edges of the tongues would be segmental and parallel to the outer edge
agreeing to the working surface of the rings; and the short ends on the outside of
the plates may be square or nearly radial where they join the inner parallel tongues,
and fit their grooves of the same shape in the ring. In this way, any steam
getting in at these end joints from the outside, would first enter and act between
the outer joint of the tongues and that of the rings, and so press the plates back
against their inner bearing surface in the grooves or recesses of the piston ring,
and thus tend to make perfect fluid-tightness. In some cases the inner recessed part
in which the tongues worked may be deeper than the outer edge part. And
although I have described these plates with square checks from the inside joining
the parallel tongues, they may be made with long angled tongues instead of checked
tongues as described when made of one depth or thickness and act nearly
equivalently as to fluid-tightness, the long inner tongue ends being the distinguishing
feature of these plates. In some instances the centre part of the back of the plate
in a line with the front part within the end tongues may be made to project back
through the ring, and so have the plate level with the top surface of the ring all
through, and this part might have a flange projecting down to screw it to one end
of the rings, allowing the other freedom of spring action, instead of having the
countersunk screw on the top of the plate as is common.
Dated the 4th March 1901
W. R. M. THOMSON & Co.,
96, Buchanan Street, Glasgow, 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 particularly described and ascertained in and by the
following statement in writing, that is to say :-
This invention has reference to improvements in and relating to the packing

page_text: rings of pistons for motive power cylinders and other purposes, and comprises a
new mode of and construction of side or tongue plates for fitting on to rings at the
joints where these are cut next the junk ring and rim of the piston where the steam
or pressure-fluid most easily enters to pass into the piston and which will render
these joints more perfectly steam or fluid-tight than heretofore.
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 Figures 1 and 2 represent a
front view and plan respectively of part of two piston packing rings A. A, and their
springs B, at one of the joints Al A', with the new or improved tongue pieces a, as
fitted in accordance with my improvements. And Figure 3 is a transverse
section corresponding to and at right angles to Figure 1, as taken through the
joints A and tongue pieces a..
Referring to these drawings.-The improvements consist in forming each of the
improved tongue plates a into and over the cut joints A' of the piston rings A
of a parallel thickness as seen in Figure 1, and less than the width of the
piston ring A. at the joint part as seen in Figure 2, with inner tongue end
projections a¹, a², fitted into the corresponding parallel grooves of the same
depth as the thickness of these plates, leaving a thickness at A² of the ring A
inside each plate, the parallel tongue parts a¹ a preferably having semicircular
ends in plan view, and these plates may be fixed by a countersunk headed
screw a through them into one end of the rings A, and in that case the pro-
jection or tongue a' at that end need not be so long as the end a² in its groove
in the spring end of the ring A which moves on the tongue plate a when
expanded by its spring B. The side edges of the tongues a are made segmental
and parallel to the outer edge agreeing to the working surface of the rings A, as
seen in the plan view Figure 2; and the short check ends at a³ of the grooves on
the outsides of the plates a may be square or nearly radial where they join the
inner parallel tongues a¹ a² and fit their grooves of the same shape in the ring A.
In this way, any steam getting in at these end joints from the outside, would first
enter and act between the outer joint of the tongues a¹ a² and that of the rings A,
and so press the plates a back against their inner bearing surface in the grooves or
recesses at A' of the piston ring A, and thus tend to make perfect fluid-tightness.
In some cases the inner recessed part of the rings A, under and in which the
tongues a' a² worked, may be deeper than the outer edge part at a.
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 herein described mode of constructing piston packing rings with side
joint plates having inner tongue end projections, or extensions, substantially as set
forth and shown in the accompanying drawings.
Second. Piston packing rings formed or fitted with side joint plates having
tongue end projections or extensions, substantially as herein described, in reference
to and shown in the accompanying drawings.
Dated the 2nd December 1891.
W. R. M. THOMSON & Co,
96, Buchanan Street, Glasgow, Agents.