IMPROVEMENTS IN PISTONS, AND RINGS FOR STUFFING BOXES
Year: 1886

page_text: We ARTHUR THOMAS ALLEN, and HENRY CAVILL Hallamshire Engineering
Works Sheffield in the County of York, Engineers, do hereby declare the nature of
our invention for IMPROVEMENTS IN PISTONS, AND RINGS FOR STUFFING BOXES
and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement, that is to say:-
Our invention is for constructing pistons and stuffing boxes in a simple and
effective manner and refers more particularly to the construction of the rings used
in such mechanical work.
And so that our invention may be fully and clearly understood we annex a sheet
of illustrative drawings.
Figs 1. 2. 3. 4. 5. 6 show the principle of our invention, being a combination of
spring and ring, having both a vertical and a lateral pressure when in use.
Fig. 7, is a sectional view of piston with the ring No 2 in action.
In carrying out our invention, we (in the case of a piston) we make the piston
block A, Fig. 7, with an annular recess or groove B, to receive the ring C, the top
of the said recess being formed by the cover D.
The top and bottom faces (a and b) of the annular recess are inclined, so that
the opening is wider than the back, or somewhat V shaped.
The ring may be made of any suitable material, such as steel, german silver, or
aluminium, of any of the cross sections shown in the sheet of drawings, or
modifications of them, embodying the principle they contain.
The rings are formed from bars of steel or other elastic material, rolled or shaped
to any of the cross sections shown, or to their equivalents, and when properly
finished are fitted in the recesses or grooves in the piston.
In Fig. 7, we have shown a ring of the section as Fig. 2 in working position in
the piston block, and being compressed to get it into the position shown, its
reacting force is twofold; first expansive force in a vertical direction, which keep
the faces c, d, of the ring, tight against the inclined faces a, b, of the piston,
second a lateral force, or tendency of the ring to escape from the narrow end of
the recess B, which consequently presses the periphery of the ring against the
cylinder E, thus there is all the action required in a piston without the use of
separate springs.

page_text: Although we have described a piston as made with one spring ring only, we may
if desirable use two springs, and the piston block may be made solid, that is
without a cover, the recess being turned out of the solid; the ring or rings may be
constructed in segments.
We consider that pistons constructed according to our invention are especially
suited for quick running Engines.
In applying our invention to stuffing boxes of Piston rods, and similar pur-
poses, we reverse the construction of the ring, and the inclined annular recess, so
that the ring shall be compressed and close upon the rod.
Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare that what
we claim is :-
In the construction and manufacture of Pistons and stuffing boxes, the use of
elastic rings of the cross sections shown in Figs 1 to 6 inclusive or their equivalent
sections, which when compressed in a tapered annular recess or groove, exert a
vertical and lateral pressure for the purpose specified, substantially as described
and illustrated.