Improvements in or relating to Packing-arrangements for Producing Fluid-tight Joints.
Year: 1894

page_text: Date of Application, 11th Aug., 1894
Complete Specification Left, 8th June, 1895-Accepted. 27th July, 1895
PROVISIONAL SPECIFICATION.
Improvements in or relating to Packing-arrangements for Producing
Fluid-tight Joints.
We, HENRY CHARLES PLATTS, and THOMAS LOWTHER, both of Hughesoffka,
Government of Ekaterinoslaff, South Russia, Engineers, do hereby declare the
nature of this invention to be as follows:-
This invention consists in improvements in or relating to packing-arrangements
for producing fluid-tight joints, and its principal object is to produce an improved
packing-arrangement suitable for the pistons and similar devices of steam, blowing,
and other engines, whereby the packing, whilst being kept in close contact with
the surface with which it is sought to obtain a fluid-tight joint, may be yet caused
to press very lightly thereon, thus, ensuring a minimum of friction and enabling
comparatively light springs to be used, so that the weight of pistons and similar
devices and the wear of the packing and the cylinders thereof may be very
materially reduced.
A packing-arrangement according to this invention comprises one or more, belts
(which may be of flexible material) of suitable thickness and width held in a
suitable groove or grooves in the periphery of the piston or similar device
(hereinafter referred to as the piston). The belt (or each of them if several are
used) is of such a length that one of its ends overlaps the other; and it is pressed
outwards in all directions towards the cylinder-wall by means of springs of helical,
zig-zag, or other suitable form, which are arranged in one or more circumferential
rows on the inner side of the belt and are inserted between, and retained by means
of projections attached to the belt. These projections may be conveniently formed
by angle or T-pieces fastened to the belt by bolts, rivets, or any other suitable
means provided on both sides of their projecting part with horns or other devices
for the purpose of holding in place the ends of the springs. The effect of the
action of the springs (which may or may not be in compression) is to keep the
packing interposed between the cylinder-wall and the belt constantly in close
contact with the wall of the cylinder by means of a gentle pressure at many points
produced by the pressure transferred from spring to spring in combination with
that produced locally by individual springs.
The number of rows of springs employed may vary according to circumstances.
When more than one row are used, it is preferred, in order to obtain a more
uniform and effective pressure against the cylinder-wall, that the retaining-
projections of one row shall not be arranged opposite those of adjacent rows or in
other words so that the springs in one row shall break joint with those in the
adjacent row. The rows of springs may either be continuous, the terminal
projections of the belt being connected by a spring or springs of suitable length;
or be broken, either by the omission of one or more of the springs that connect the
terminal projections or by that of one or more of the other springs, an arrangement
of advantage in cases in which the wear of a cylinder has not been uniform. In
cases where it is desirable that little room should be taken up by the springs
between the belt and the piston, the springs may be made of a somewhat elliptical
or Hattened form in cross-section.
The belt may be modified by making it in several sections; in this case each
section may overlap an adjacent section, or each section may be hinged to adjacent

page_text: sections and one of the ends of the terminal sections forming the ends of the belt
made to overlap the other. In some cases the belt itself may be used as the
packing; but for convenience of renewal and repair it is preferable to employ one
or more rings of packing, either metallic or non-metallic, between the belt and the
cylinder-wall. The non-metallic packing that it is preferred to use is composed of
a woven fabric the warp of which consists of asbestos and the weft of wool; or
vice versa. This packing may also be used in making fluid-tight joints according to
other methods.
Improvements in or relating to Packing-arrangements for Producing
Fluid-tight Joints.
We, HENRY CHARLES PLATTS, and THOMAS LOWTHER, both of Hughesoffka,
Government of Ekaterinoslaff, South Russia, Engineers, 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 :-
This invention consists in improvements in or relating to packing-arrangements
for producing fluid-tight joints, and its principal object is to produce an improved
packing-arrangement suitable for the pistons and similar devices of steam, blowing,
and other engines, whereby the packing, whilst being kept in close contact with
the surface with which it is sought to obtain a fluid-tight joint, may be yet caused
to press very lightly thereon, thus ensuring a minimum of friction and enabling
comparatively light springs to be used, so that the weight of pistons and similar
devices, and the wear of the packing and the cylinders thereof, may be very
materially reduced.
A packing-arrangement according to this invention comprises one or more belts
(which may be of flexible material) of suitable thickness and width, held in a
suitable groove or grooves in the periphery of the piston or similar device
(hereinafter referred to as the piston). The belt (or each of them if more than one
are used) is of such a length that one of its ends overlaps the other; and it is
pressed outwards in all directions towards the cylinder-wall by means of springs of
helical, zig-zag, or other suitable form, which are arranged in one or more
circumferential rows on the inner side of the belt and are inserted between and
retained by means of projections on the belt. These projections may be con-
veniently formed by angle or T pieces fastened to the belt by bolts, rivets, or any
other suitable means and provided on both sides of their projecting part with horns
or other devices for the purpose of holding in place the ends of the springs. The
effect of the action of the springs (which may or may not be in compression before
being placed in position around the piston, but should always be in compression
when finally in position) is to keep the packing interposed between the cylinder-
wall and the belt, constantly in close .contact with the wall of the cylinder by
means of gentle pressure at many points produced by the pressure transferred
from spring to spring in combination with that produced locally by individual
springs.
The number of rows of springs employed may vary according to circumstances.
When more than one row are used, it is preferred, in order to obtain a more
uniform and effective pressure against the cylinder-wall, that the retaining-
projections of one row shall not be arranged opposite those of the adjacent row or

page_text: rows, or, in other words, that the springs in one row shall break joint with those in
the adjacent row or rows. The rows of springs may either be continuous, the
terminal projections of the belt being connected by a spring or springs of suitable
length, or be broken, either by the omission of one or more of the springs that
connect the terminal projections, or by that of one or more of the other springs, an
arrangement of advantage in cases in which the wear of a cylinder has not beeu
uniform. In cases where it is desirable that little room should be taken up by the
springs between the belt and the piston, the springs may be made of a somewhat
elliptical or flattened form in cross-section.
The belt may be modified by making it in several sections; in this case each
section may overlap an adjacent section, or each section may be hinged to adjacent
sections and one of the free ends of the terminal sections forming the ends of the
belt be made to overlap the other. In some cases the belt itself may be used as
the packing but for convenience of renewal and repair it is preferable to employ
one or more rings of packing, either metallic or non-metallic, between the belt and
the cylinder-wall.
In the accompanying illustrative drawings,
Fig. 1 represents a partial section, taken circularly along the line a a of Fig. 2,
through a piston provided with a packing arrangement according to this
invention;
Fig. 2 a partial radial section along the line
of Fig. 1 ; and
Fig. 3 a partial cross-section on the line cc of Fig. 1.
Figs. 4, 5, and 6 show, in back elevation, side elevation, and plan respectively,
one of the projections or devices between which the springs are inserted.
The remaining figures are hereinafter referred to.
1. is a belt of flexible material, such as arranged within an annular groove 2* in
the periphery of a piston 2 and made of such a length that one of its ends 1ª
overlaps the other 1. It is pressed outward in all directions towards the cylinder-
wall 3 by coiled springs 4 arranged in three circumferential rows on the inner side
of the belt 1 and retained in place by means of projections 5 which are formed (see
Figs. 4, 5, and 6) of tee-shaped pieces of suitable material such as metal, fastened
to the belt 1 by rivets 6 and each provided on both sides of its projecting part 5ª
with horns 7 for the purpose of holding in place the ends of the springs. 8 is a
packing ring composed of woven packing-material, but this packing ring may be.
constructed of metal also.
The springs may or may not be in compression before the belt is bent around
and placed within the piston, by which means they will of course be placed in
compression. By giving the springs an initial compression, that is, by using
springs the ordinary length of which is such that when engaged with the horns 7
of the projections 5 whilst the belt is off the piston, they will be in a state of
compression, which is the arrangement preferred, the belt can, when in use, be
caused to exert a greater pressure on the packing 8 than will be the case when the
springs have no such initial compression. The central portion of each spring will
naturally, when put into compression, assume a curve in some direction or the
other, but the spring should be prevented from curving out sideways or towards.
the other springs, when more than one row are employed. For this purpose the
middle part of each spring is arranged to pass through a guide which may be made
channel shape in cross section and is rivetted or otherwise attached to the inner
side of the belt. By reason of its tendency to curve in some direction each spring
when compressed may be caused to curve either towards the piston body or towards
the belt 1. The natural tendency of the springs to become curved on being
subjected to compression can therefore be utilized to assist in making the belt 1
press more effectively on the packing, either by making the central portion of the
springs press against the piston body as shown at the right hand side of Fig. 3; or
against the belt and thus on the packing as shown in the left hand side of Fig. 3..
The former plan is useful in the case of horizontal engines, for causing the bottom
springs to raise the body of the piston and so prevent it from riding upon the

page_text: bottom portion of the cylinder wall, the springs in this case being suitably
constructed that is to say made of sufficiently stiff wire and the ends adapted to
bear well upon the tee-pieces, and being compressed sufficiently to effect the purpose
aimed at.
By the construction and arrangement described, it will be seen that while the
action of each set or chain of springs 4 is continuous, it is at the same time local,
each spring exerting an independent and separate pressure upon a definite
corresponding and adjacent part of the belt 1 and packing 8. Consequently light
springs can be used and the packing caused to press very lightly against the wall
of the cylinder, thereby enabling a tight joint to be obtained with a minimum of
friction and weight of the packing arrangement.
In the arrangement represented in Figs. 1, 2 and 3, the springs 4 are shown as
helical or coiled springs of circular form in cross-section. Where it is desirable
that the coiled springs should take up little room between the body of the piston
and the belt 1, they may be made of a flattened or oval form in cross-section, as
shown in Fig. 7; or a zig-zag form of spring such as shown respectively in side
elevation and cross section in Figs. 8 and 9 may be used. In the latter case, the
ends of the springs may be formed as shown at 4* (Fig. 8) to enter tubular
projections 7 on the projecting devices 5 attached to the belt 1.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to he performed we declare that what we
claim is :-
1. In a packing-arrangement a flexible or other belt or packing made in one or
in seotions in combination with a number of helical, zig-zag or other suitably
shaped springs arranged circumferentially between the belt or packing and the
piston or body carrying the same, the springs being adapted to force the belt or
packing towards the surface with which a fluid-tight joint is to be formed and
being located between, and retained in place by, projections so that each spring
can act independently of the others, substantially as herein described.
2. A packing-arrangement of the kind specified in Claim 1, in which the ends
of the springs are retained in position by angle or tee-shaped pieces 9 provided
with horns 11, substantially as hereinbefore described with reference to the
accompanying drawings.
3. Our improved packing-arrangement constructed arranged and operating as
herein before described with reference to the accompanying illustrative drawings,
whether the springs be of helical or other form as set forth.
Dated this 8th day of June 1895.
Dated this 8th day of June 1895.
For the Applicants,
W. LLOYD WISE,
46 Lincoln's Inn Fields, London, W.C., Chartered Patent Agent..