Improvements in Packing Springs for Pistons and Plungers.
Year: 1887

page_text: Date of Application, 12th Jan., 1887
Complete Left, 2nd Mar:, 1887:
Complete Accepted, 5th Apr., 1887.
PROVISIONAL SPECIFICATION.
.Improvements in Packing Springs for Pistons and Plungers.
We HENRY LANCASTER and RICHARD FLETCHER CHRISTMAS TONGE of the firm
of Lancaster and Tonge of Withington Street, Pendleton, Manchester, in the County
of Lancaster Engineers, do hereby declare the nature of this Invention to be as
follows
Our said Invention relates to metallic springs which are employed to press the
packing rings of pistons, pump buckets, plungers and the like against the interior of
ihe cylinder or pump barrel so as to prevent the steam or other fluid from passing the
piston or plunger when working, as is well understood. In a certain type of piston
the packing rings are expanded by a coiled helical spring which is situated in an
annular recess or groove formed in the piston. The piston packing rings surround
and enclose the spring and are expanded outward thereby. This class of spring has
however the drawback that in the larger size of pistons the depth of the recess or
groove holding the spring is excessive and is the cause of inconvenience. We have
therefore devised a novel form of spring which has all of the advantages of the
ordinary helical spring but which, occupies considerably less depth when applied to
the piston. The improvement consists in coiling the spring to a D form in section
instead of the ordinary circular shape the improved spring being thus practically of a
semi-circular instead of a circular section. When laid into the groove in the piston
block the flat side of the D shaped spring lies parallel with the bottom of the groove
while the semicircular portion presses upon the packing rings, so as to force them
outward and apart in the manner at present effected by the spring of circular section.
Our improved spring thus occupies a space or radial depth of not much more than
the half of the space at present occupied by similarly applied springs of a circular
section:
H
1007
DUTTON & FULTON;
1, St. James Square, Manchester,
Agents.

page_text: COMPLETE SPECIFICATION.
Improvements in Packing Springs for Pistons and Plungers.
We HENRY LANCASTER and RICHARD FLETCHER CHRISTMAS TONGE of the firm
of Lancaster and Tonge of Withington Street, Pendleton, Manchester, in the County
of Lancaster, 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 and accompanying drawings :-
Our said Invention relates to metallic springs which are employed to press the
packing rings of pistons, pump buckets, plungers and the like against the interior of
the cylinder or pump barrel so as to prevent the steam or other fluid from passing the
piston or plunger when working, as is well understood. In a certain type of piston
the packing rings are expanded by a coiled helical spring which is situated in an
annular recess or groove formed in the piston. The piston packing rings surround
and enclose the spring and are expanded outward thereby. This class of spring has
however the drawback that in the larger size of pistons the depth of the recess or
groove holding the spring is excessive and is the cause of inconvenience. We have
therefore devised a novel form of spring which has all of the advantages of the ordinary
helical spring but which occupies considerably less depth when applied to the piston.
The improvement consists in coiling the spring to a D form in section instead of the
ordinary circular shape the improved spring being thus practically of a semi-circular
instead of a circular section. When laid into the groove in the piston block the flat
side of the D shaped spring lies parallel with the bottom of the groove while the
semicircular portion presses upon the packing rings so as to force them outward and
apart in the manner at present effected by the spring of circular section. Our
improved spring thus occupies a space or radial depth of not much more than the half
of the space at present occupied by similarly applied springs of a circular section.
And in order that our said invention may be properly understood we will now
proceed more. particularly to describe the same reference being had to the annexed
sheet of drawings.
Fig. 1 of the said drawings is a cross sectional view of a steam piston composed
mainly of two parts viz: the piston block A and the junk ring B.
Fig. 2 is a view of the piston at right angles to Fig. I with the junk ring B
removed so as to show more clearly the spring c and the rings d.
C
In Fig. 2 part of the spring e is removed to show the rings & more clearly. The
packing rings d are contained in the groove e formed in the periphery of the piston
and the spring, which is also situated in the groove e and beneath the packing rings d
presses the rings, outward and apart as is well. understood. In pistons of the type
illustrated in the drawings and in similar types wherein the pressure on the packing
rings is imparted by means of a coiled spring, the groove e to contain the spring and
rings has sometimes to be made of excessive depth where a circular coiled spring is
used. To reduce the depth of the spring and consequently the depth of the groove e

page_text: we coil the spring c which is made as usual from tempered steel of a D form as clearly
shown at Fig. 1 of the drawings, thus diminishing the depth of the spring by about
one half while at the same time preserving to a great extent the useful properties of
the coiled spring of circular section. The ends of the spring may be attached or they
may form an unattached butt joint. The accompanying drawing is intended to
illustrate a convenient application of the spring but it will be understood that our
improved D form of spring is applicable in all situations in pistons, pump buckets and
the like where coiled springs of a circular section have hitherto been used, and in some
instances it may be used instead of flat springs where such have been employed for
similar purposes.
A single spring or two or more springs abreast may be used to act
on the rings d.
Having now particularly described and ascertained the nature of the said invention
and in what manner the same is to be performed we declare that what we claim is :-
'
In prime motor pistons, pump buckets and the like the employment of a coiled
spring or of coiled springs of a semi-circular or D form in section applied and acting
substantially in the manner and for the purposes hereinbefore described and shown.
Dated this 28th day of Wahr 1997
DUTTON & FULTON,
1, St. James Square, Manchester,
Agents.