IMPROVEMENTS I PISTONS
Year: 1877

page_text: LETTERS PATENT to John George Cameron, of the Town and County
Kingston-upon-Hull, Engineer, for the Invention of " IMPROVEMENTS I
PISTONS
"
Sealed the 7th December 1877, and dated the 13th June 1877.
PROVISIONAL SPECIFICATION left by the said John George Cameron at
the Office of the Commissioners of Patents on the 13th June 1877.
JOHN GEORGE CAMERON, of the Town and County of Kingston-upon-Hull,
Engineer. IMPROVEMENTS IN PISTONS."
"
My Invention relates to pistons for steam, air, water, and other fluids, and its has
for its object providing an efficient packing, which shall be compensating and
equable or uniform in its action upon the packing rings.
i
In carrying out my Invention in order to effect this object, I employ for
exercising pressure upon the packing ring a corrugated spring, constructed either
in one piece or in two or more lengths or segments, secured together or arranged
by butt joints or otherwise, so as to work in unison as a connected whole. This
spring is fitted in the body of the piston, so as to leave a free space or clearance
between its internal salient portions and the periphery of that portion of the body.
which the spring surrounds for the purpose of utilizing the whole of the elasticity
of the latter to act upon the packing rings without any impediment to such elastic
action by the contact of the body of the piston with the internal portions of the
spring.
The tension of the spring may be adjusted by the insertion of packing strips at
the meeting or junction points of the spring or of its segments, the effect of the
introduction of one or more of such compensating strips being distributed uniformly
throughout the whole extent of the spring.
In the case of pistons having V shaped packing rings, the spring may be
provided at its external salient points with blocks, which at their exterior fit the
interior of the packing rings, and are slotted for the reception of the spring-set.
screws being employed for maintaining the spring. in position therein...

page_text: The junction of the ends of the spring or of its segments may also be effected by
means of fish plates with slots or other provision for longitudinal adjustment or
compensation, and a wedge or other plate may be interposed between the two ends
of the spring or of its segments, for the facility of adjusting the tension of the
spring on fitting the piston, and for future adjustment to compensate for wear by 5
the insertion of filling strips or otherwise.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John George Cameron, in the Great Seal Patent Office on the 13th
December 1877.
JOHN GEORGE CAMERON, of the Town and County of Kingston-upon-Hull,
Engineer. "IMPROVEMENTS IN PISTONS."
My said Invention relates to pistons for steam, air, water, and other fluids, and it
has for its object providing an efficient packing, which shall be compensating and
equable or uniform in its action upon the packing rings.
In carrying out my said Invention in order to effect this object, I employ for
exercising pressure upon the packing ring or rings an annular corrugated spring,
constructed either in one piece or in two or more lengths or segments, secured
together or arranged by butt-joints or otherwise, so as to work in unison as a
connected whole. This spring is fitted in the body of the piston, so as to leave a
free space or clearance between its internal salient portions and the periphery of s
that portion of the body which the spring surrounds for the purpose of utilizing the
whole of the elasticity of the latter to act upon the packing rings without any impedi-
ment to such elastic action by the contact of the body of the piston, or any other
part with the internal portions of the spring.
The tension of the spring may be adjusted on fitting the piston by the insertion
of packing strips, pins, or wedges, at the meeting or junction points of the spring
or of its segments, the effect of the introduction of one or more of such strips, pins,
or wedges being distributed uniformly throughout the whole extent of the spring.
This arrangement also offers facilities for future adjustment by the interposition of
filling strips or otherwise in order to compensate for wear, and maintain the initial;
tension.
Ι
The junction of the ends of the spring or its segments may be effected by means
of fish plates with slots or other provision for the said adjustment or compensation.
In the case of pistons having V shaped packing rings, I may employ, at the parts
where the external salient portions of the spring occur, blocks so constructed as to
fit at their exterior the interior of the packing rings, and slotted, grooved, or
recessed for the reception of the spring, set screws being added, if necessary, for
maintaining the spring in position.
And in order that my said Invention may be fully understood, I shall now
proceed more particularly to describe the same, and for that purpose shall refer to
the several Figures on the annexed Sheet of Drawings, the same letters of reference
indicating corresponding parts in all the Figures.
Figures 1 and 2 of my Drawings represent respectively a vertical section and
sectional plan of a piston with a corrugated spring fitted thereto, according to one
modification of my said Invention.

page_text: . Figures 3 and 4, Figures 5 and 6, Figures 7 and 8, Figures 9 and 10, and Figures
11 and 12, are similar views to Figures 1 and 2, but drawn to a larger scale of a
portion of a piston illustrating five other modifications of my said Invention.
Figures 13, 14, and 15, are detail sectional views illustrating various modes of
fitting or connecting the ends of the spring or its segments, and packing the
same.
A is the body of the piston, and B the packing ring or rings between which and
the body A I provide an annular chamber a for the reception of a corrugated spring
C, the corrugations of which run parallel, or nearly so, with the axial line b, b, of
the piston. The chamber a and the spring C are made of such relative dimensions
that a free space or clearance is left between the internal salient portions c of the spring
and the body A of the piston, whilst the external portions & of the spring act upon
the packing ring or rings B, either directly, as shewn in Figures 1, 2, 3, 4, 5, and 6,
or through the intervention of intermediate blocks D, as illustrated in Figures
7, 8, 9, 10, 11, and 12.
When plain packing rings B are employed, as in the arrangement shewn in
Figures 1 and 2, I use a plain corrugated spring, the external salient portions d of
which act directly upon the packing ring. When, however, angular packing rings
are adopted, as in the other examples illustrated, the spring may be either bent
inwards at the top and bottom, at the parts where the external salient portions d
occur, as shown at d³, d', Figures 3 and 4, or be formed at the parts situate between
the internal salient portions c with conoidal projections or horns d. (Figures 5 and 6),
so as to fit and act against the angular portions e of the rings B in such a manner
as to exercise vertical as well as outward pressure thereon, or in lieu of these
arrangements intermediate blocks D may be used, as shewn in Figures 7, 8,
9, 10, 11, and 12, and herein-before referred to. These intermediate blocks
may be arranged in various ways, several examples of which I have given in my
Drawings. In Figures 7 and 8 they are represented as formed with their inner
faces concave for the reception of the external salient portions of the spring
In the arrangement shewn in Figures 9 and 10, the blocks D are slotted at f for the
reception of the springs which pass through them, set screws g being employed
for maintaining the spring in position therein.
In the modification illustrated by Figures 11 and 12, the blocks D are formed with
conoidal recesses or cavities at their inner side, in which fit conoidal projections <
provided on the spring.
In all cases the spring is either constructed in one piece, as shewn in Figure 2, or
in two or more lengths or segments secured or fitted together so as to form practically
one spring.
The junction of the ends of the spring or of its segments may be effected by
means of a fish plate, as shewn at in the detail Figure 13, the holes at i in the plate
through which the attaching screws k pass being made elongated so as to admit of
the ends 1, 2, of the spring being separated to the requisite distance for the intro-
duction of filling strips for the purpose of adjusting its tension, or the ends of the
spring may be bent back, as shewn at 1, 2, in Figure 14, or fitted with angle irons m,
as shewn in Figure 15, the spring ends or the angle irons, as the case may be,
being suitably shaped for the reception between them of a wedge or filling piece
7, by adjusting which and inserting additional strips, if necessary, the tension of
the spring may be regulated on fitting the piston, and subsequently in order to com-
pensate for wear and maintain the initial tension. -
In all cases the effect of the introduction of one or more wedges, filling pieces, or
strips becomes distributed uniformly throughout the whole extent of the spring,
which is thus equable in its action upon the packing rings. By reason, moreover,
of the free space or clearance left between the internal salient portions of the
spring and the periphery of that portion of the body of the piston which the
spring surrounds, the whole of the elasticity of the latter is utilized to act upon the
packing rings without any impediment to such elastic action by the contact of the
body of the piston, or of any other part with the internal portions of the spring.

page_text: Having now described and particularly ascertained the nature of my said
Invention, and the manner in which the same is or may be used or carried into
effect, I would observe, in conclusion, that I am aware that it has previously been
proposed to employ a corrugated spring or springs for exercising pressure upon the
packing or rings of a piston, and therefore to this feature in itself I lay no claim;
but what I consider to be novel and original, and therefore claim as the Invention
secured to me by the herein-before in part recited Letters Patent is, the employ-
ment in pistons of an annular corrugated spring, constructed either in one piece or
in lengths or segments fitted or secured together, so as to form practically one
annular corrugated spring, the corrugations of which run parallel, or nearly so, with
the axial line of the piston, and the tension of which is adjustable at will; in
combination with a packing ring or rings with or without the intervention of inter-
mediate blocks, and with a piston body arranged in such a manner that an annular
space or clearance shall be left on the inner side of the spring in order to admit of
the free action of the latter, and thus render available the whole of its elasticity in
exercising an equable or uniform pressure upon the packing ring or rings, all
substantially as herein-before described, and illustrated by the accompanying
Drawings.
In witness whereof, I, the said John George Cameron, have to this my
Specification set my hand and seal, the Seventh day of December, One:
thousand eight hundred and seventy-seven.