Improvements in Piston Springs and in the Method of Producing the same.
Year: 1887

page_text: Date of Application, 13th July, 1887.
Complete Left, 26th Aug., 1887:
Complete Accepted, 27th Sept., 1887.
Improvements in Piston Springs and in the Method of Producing
the same.
I RICHARD TONGE of Alderley Edge in the County of Chester, Merchant, do hereby
declare the nature of this Invention to be as follows:-
My Invention relates to the metallic pistons principally used in steam machinery
but applicable for use in pumps or for other similar uses as is well understood. The
said pistons are provided with metal rings which derive a yielding elastic support
from metal springs. In early forms of such pistons the packing rings were supported
by means of a spiral spring which was made of cast iron and turned and cut to its
finished form in a lathe. It is to such pistons that my Invention relates my intention
being to simplify and cheapen the production of the springs and at the same time to
increase their efficiency. To this end I form each piston ring from spring steel of a
round square oval rectangular or other suitable section. I bend a rod of such steel
into a spiral form and reduce the metal at the two ends of the spiral by turning in a
lathe or by suitable means so as to obtain two flat surfaces parallel with each other
and forming right angles with the axis of the spring. The spring so formed is by
preference hardened and tempered in order that it may retain its elasticity
permanently or for a considerable time. Such springs retain their elasticity for a
much longer period than the ordinary cast iron springs.
DUTTON & FULTON,
1, St. James Square, Manchester,
Agents.

page_text: COMPLETE SPECIFICATION.
Improvements in Piston Springs and in the Method of Producing
the same.
I RICHARD TONGE of Alderley Edge in the County of Chester, Merchant, 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 and
accompanying drawings:
My Invention relates to the metallic pistons principally used in steam machinery
but applicable for use in pumps or for other similar uses as is well understood. The
said pistons are provided with metal rings which derive a yielding elastic support from
spirally formed metal springs. To cheapen the production and increase the efficiency
of such piston springs I form them from steel of a round dee shape oval or other
suitable section. I bend a rod of such steel into a spiral form and reduce the metal at
the two ends of the spiral by turning in a lathe or by suitable means so as to obtain
two flat surfaces parallel with each other and forming right angles with the axis of the
spring. The spring so formed is hardened and tempered in order that it may retain
its elasticity permanently or for a considerable time.
And in order that my said invention may be properly understood I will now pro-
ceed more particularly to describe the same with reference to the annexed sheet of
drawings.
Fig. 1 of the said drawings is a cross section of a metallic piston fitted with a
spring made in accordance with my invention. Fig. 2 is a plan view of the piston
with the cover removed so as to show the spring in position. Fig. 3 is a view of my
improved spring removed from the piston. The piston is composed of two parts a and b
secured together in any suitable manner. An annular recess c is formed in the
piston and in this recess are placed the elastic metallic packing rings d. e.
Beneath
the rings d. e is situated the spirally coiled spring to which iny invention relates.
When the spring is apart from the piston it is of the appearance indicated at Fig. 3
but when forced into the groove è in the piston and surrounded by the packing
rings d. e it is pressed more closely together and exerts both an outward or radial pressure
and a pressure which in a piston moving in a vertical direction would be upward and
downward thus pressing the rings d. e. into steam or fluid tight contact not only with
the interior of the cylinder but also with the two opposed sides of the recess.
springs similar in character to that constituting my invention and composed of flat
steel or cast iron coils it has been found that the extended frictional contact between
the flat backs of the spiral coils and the interiors of the packing rings d. e militates
greatly against the preservation of an easy elastic contact between the spring and the
rings and in a flat and comparatively thin steel or iron coil the upward and downward
pressure on the rings is necessarily very weak but these objections are obviated by the
employment of the springs made from round steel. As will be observed when looking
at Fig. 1 my improved spring is made from a steel rod of a circular section. The
In

page_text: steel rod is coiled upon a mandril and is afterwards turned or ground at both ends so
as to present flat surfaces on each side of the spring. The spring is then tempered
and is ready for use. When the spring is in position the aforesaid flat surfaces come
in contact with and press against the inwardly projecting lip or flange on each of the
rings d. e. the spring being so turned or ground that contact exists between the ends
of the spring and the flanges on the rings almost all the way round when the spring
has been forced into position in the piston. The ground or flattened ends of the
spring are indicated at in Fig. 3 and appear as the unshaded portion of the
spring in Fig. 2. It will be observed on reference to Fig. 1 that the rounded
backs of the coils of the spring press upon the interiors of the rings d. e.
In virtue of the round section of the spring coil the contact between the rings and the
rounded backs of the coils is very limited and consequently there is no danger of the
easy working of the spring and coils being impeded by excessive frictional contact or
of the rings and spring sticking together and destroying each others elasticity as is
frequently the case when springs of the well known flat section are used. My
improved spring is also capable of imparting a greater thrust in the direction of
movement of the piston than the flat spring and therefore packs the rings better
against the sides of the recess in the piston or against the piston block and the junk-
ring or cover. As the improved spring is made from ordinary round rod steel and is
not subjected to any special rolling, shaping or other preparatory or finishing operation
other than the flattening of the ends as aforesaid, such springs can be produced in a
very speedy and economical manner. Of course it will be evident that as a salient
advantage of my improved spring is that the coils have a rounded back so as to
effect a very limited contact with the rings, I might use any section of steel, other
than a round section, which would have a similar effect. For example I might use
steel of a half round section as shown at Fig. 4 or of a triangular section with one
angle rounded off as at Fig. 5 or a dee section such as indicated by Fig. 6. or a semi-
tubular section as at Fig. 7 or any other similar section which would have the
useful effect set forth. The recess in the piston may be of the form indicated in
Fig. 1 or may have ledges to support the packing rings d. e as described and
shown in the specification of Letters Patent No. 11447 granted to me on the ninth
day of September 1886.
Having now particularly described and ascertained the nature of the said invention
and in what manner the same is to be performed I declare that what I claim is :-
(1) In piston or plunger packing springs of the indicated nature that is to say
composed of spirally coiled steel, coiling the said springs from a rod or bar of
steel of a circular, semi-circular, triangular or other suitable section in such a
manner as that the tempered and finished spring when ground or otherwise
flattened at the ends and placed in position in the piston will present rounded narrow
or limited contact surfaces to the interior of the surrounding elastic packing rings so
as (inter alia) to avoid excessive frictional contact between the rings and the spring
substantially as hereinbefore described and shown.
(2) A spirally coiled piston or plunger spring of the indicated nature and made
from steel of one of the indicated sections for the purposes and substantially as herein-
before described and shown.
1000
DUTTON & FULTON,
1, St. James Square, Manchester,
Agents.