IMPROVEMENTS IN THE CONSTRUCTION OF METALLIC PISTONS
Year: 1884

page_text: We JOHN QUALTER and EDWARD HALL of the Railway Foundry Barnsley in
the county of York Mechanical Engineers do hereby declare the nature of our
invention for "IMPROVEMENTS IN THE CONSTRUCTION OF METALLIC PISTONS " to
be as follows :-
--
This invention has for its object improvements in the construction of metallic
pistons in which steel or like expansible packing rings are used to keep the piston
face in contact with the cylinder of steam or like engines.
Our invention is designed to construct a simple metallic piston, the metallic
packing rings of which can be adjusted without removing the "junk ring" or
cover of the piston proper.
We arrange a split ring of steel or like resilient metal in a suitable channel or
groove in the body of the piston and fit over it at intervals lugs or bosses carrying
Laminated C-springs such as described in Letters Patent granted to the said
John Qualter and one George Bower in 1862, No. 940, pressing against the wedge-
shaped packing rings.
To expand these springs and so act on the packing rings we, according to our
invention, bevel the ends of the aforesaid split ring in opposite directions and
between the oppositely inclined faces of the ends of the split ring we insert a
wedge (in some cases we can use two or more wedges) moving on a screwed pin or
bolt in a box or case in which the wedge is free to alide vertically and the ends of
the split ring to slide horizontally. Lock nuts are fitted on the bolt or pin and a
guard cap or nut advantageously screws over the whole into a seating in the
junk ring or cover. To adjust the packing rings this guard cap or nut is
removed when the lock-nutted pin or bolt can be reached by a spanner or key and
the wedge raised or lowered, thus expanding or contracting the split ring and thus
acting on the C-springs operating the packing rings.
"
We prefer to use laminated C-springs but if desired single C or spiral springs
might be used or other suitable springs.
Instead of the wedge being drawn up to expand the ring it can be pressed down
for the same purpose in which case it is reversed as compared with the last
arrangement and the ends of the ring of course oppositely bevelled.
It can be forced down by a screwed bolt carrying a short cone-headed pin fitting
a recess in the top of the wedge the bolt passing through a nut in the “junk
ring."
Or we can arrange the wedge to slide horizontally instead of vertically and
bevel or form the ends of the split ring accordingly.
Deted this fourteenth day of November 1881

page_text: We JOHN QUALTER and EDWARD HALL of the Railway Foundry Barnsley-in
the county of York Mechanical Engineers do hereby declare the nature of the
said invention for IMPROVEMENTS IN THE CONSTRUCTION OF METALLIC PISTONS
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
j
This invention has for its object improvements in the construction of metallic
pistons in which steel or like expansible packing rings are used to keep the piston-
face in contact with the cylinder of a steam or like engine.
Our invention is designed to construct a simple metallic piston the metallic
packing rings of which can be adjusted without removing the "junk ring” or
cover of the piston proper.
And in order that our invention may be understood and carried into practical
effect we have caused to be annexed to this specification the accompanying sheets
of drawings and now refer to the figures and letters of reference marked thereon.
Fig. 1. Sheet 1. is a plan of a piston with part of the junk-ring or cover broken
away.
Fig. 2. section of same on x-Y.
Fig. 3. Elevation of the wedge adjusting the ring.
We arrange a split ring A of steel or like resilient metal in a suitable channel or
groove B in the body of the piston C and fit over it at intervals lugs or bosses D
carrying laminated springs E, such as described in Letters Patent granted to the
said John Qualter and one George Bower in 1862, No. 940, pressing against the
wedge shaped packing rings.
To expand these springs E and so act on the packing rings we, according to our
invention bevel the ends F, F, of the aforesaid split ring A in opposite directions,
and between the oppositely inclined faces of the ends of the split ring we insert a
wedge G (in some cases we can use two or more wedges) moving on a screwed pin
or bolt in a box or case I in which the wedge G is free to slide vertically and
the ends F, F, of the split ring A to slide horizontally.
Lock nuts J, J, are fitted on the bolt or pin H and a guard cap or nut K
advantageously screws over the whole into a seating L in the junk ring or cover M.
To adjust the packing rings N, N, O this guard cap or nut is removed when
the loak-nutted pin or bolt H can be reached by a spanner or key and the wedge G
raised or lowered expanding or contracting the split ring A and thus acting on the
C-springs operating the packing rings N, N¹, O.
We prefer to use laminated C-springs as described but if desired single C or
spiral springs might be used or other suitable springs.
Sheet 2 shews a very obvious modification of our invention in which the position
of the wedge G is simply reversed it being pressed down instead of drawn up to
expand the ring the ends F, F, of the ring A being bevelled to suit,
The Figures correspond to those on Sheet 1, and the various letters apply as
before with the following exceptions.

page_text: •
The nut or bolt K¹ screwing into the seating L in the junk ring is formed with
a short cone-headed pin P fitting a recess Q on the top of the wedge G (or the
pin could be in the wedge and the recess in the bolt).
A square or like. hole R is made in the bolt K¹ to fit in a key to turn same.
Instead of making the wedge G to slide in a vertical plane it could be made to
slide horizontally or diagonally to expand the ring A as will be well understood,
and we do not bind ourselves to the precise method of operating the wedge to
expand or contract the ring A though we prefer those shown.
If the wedge is arranged to slide horizontally or diagonally the ends F, F¹, of
the split ring A must be formed to suit. In all these figures S, S, are the holdfast
bolts securing the junk ring or cover to the piston body T.
The ring A may be made in two or more sections if desired that is we may use
two or more thin split rings, abutting one on the other or one stout ring, and, also,
the wedge G may be a conical one instead of a flat one if desired and be guided
suitably and fit the ends F, F, of ring A formed to suit, the various details being
arranged to correspond.
For a large piston we may use a ring or rings A split in two or more portions or
segments and use two or more wedges.
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
Firstly. The method of adjusting the packing rings of inetallic pistons as herein-
before described consisting in providing a split ring or rings (such as A) capable of
being expanded or contracted by a wedge or wedges (such as G) set up by suitable
means, such split ring or rings being arranged to press or abut on intermediate
springs E interposed between the same and the packing rings and so adjust the
said packing rings by the expansion or contraction of the split ring or rings A by
the said wedge or wedges.
I
Secondly. In a metallic piston the use of the split ring or rings A formed with
bevelled or inclined ends F, F¹, moving in a box or guide I and in combination
with a wedge G and means for adjusting the same, the said ring or rings A by
means of collars or lugs D or otherwise abutting on springs E interposed between
the same and the packing rings of the piston substantially as and for the purposes
described.
DL: 10LL
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