in and
Year: 1887

page_text: Date of Application, 14th Feb., 1887
Complete Left, 20th Oct., 1887
Complete Accepted, 22nd Nov., 1887
I ROBSON BROWN marine engineer of Belle Vue Crescent, Tyne Dock, South
Shields in the county of Durham do hereby declare the nature of this invention to
be as follows:-
For improvements in and connected with pistons.
The springs (A & B) are placed between the packing ring & body of the Piston,
the spiral springs (B) being compressed by the junk ring, and these spiral springs
pressed laterally on the flat-corrugated springs (A), 'the whole giving outward pressure
to the packing ring.

page_text: COMPLETE SPECIFICATION.
Improvements in and Connected with Pistons.
I, ROBSON BROWN of Belle Vue Crescent, Tyne Dock, South Shields, in the County
of Durham, Marine Engineer, do hereby declare the nature of this invention and
in what manner the same is to be performed to be particularly described and
ascertained in and by the following statement :-
My invention relates to the ineans whereby pistons are made steam tight in the first 5
instance, and so maintained against the wearing of the packing rings radially, and
consists of springs, of peculiar formation, so applied that they exert a radial pressure
outward against the packing ring or rings and that the adjustment of the piston cover
or "junk-ring," by screwing it down, will exert a pressure upon the springs, or some
of them, which causes the circle to expand radially with a uniform pressure behind
the packing ring or rings thus insuring equal wear between it and the interior of the
cylinder.
The peculiar form of the springs and the manner of their application will be clearly
understood by reference to the drawings filed with my Provisional Specification since
filing which I have had practical results so satisfactory that I do not propose to alter
the form nor the disposition of the springs.
The springs are applicable to any of the ordinary existing pistons, whether with
single or double packing rings, but the drawing shews them in a piston having a
single packing ring of the entire depth between the flange and "junk-ring" as now
very generally fitted for both high and low pressure pistons.
2
Referring to the drawings filed with my Provisional Specification Fig. 1. is a
sectional plan and Fig. 2. a sectional elevation of the piston. Fig. 3 shews, in plan
and elevation, one of the flat corrugated springs A, curved to the diameter of the
inside of packing ring, and Fig. 4 an elevation and end view of a portion of one of
the spiral springs B which, being compressed and inserted at intervals between the 2
springs A, exert their elastic pressure to enlarge their circle, force outward the
packing ring, with uniform pressure all round, against the inside of the cylinder and
when wear takes place the "junk-ring," being screwed down, compresses them in the
direction of their depth and thus extends their length and restores the requisite
pressure against the packing ring to force it out against the cylinder.
"
The radial pressure is exerted equally at all points of the circle and is distributed
over the entire depth of the packing ring so that it has no tendency to
" cant over
and thus cause unequal wear and leakage between its edges and the piston flange or
"junk-ring."
ย

page_text: Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed declare that what
I claim is
The application to pistons of springs, substantially of the forms described and
shewn, the combined action of which will give uniform radial pressure to expand the
packing ring or rings and insure equal wearing and steam tight contact, between the
packing ring and the cylinder, and provide for adjustment by screwing down
the "junk-ring."