Improvements in the Manufacture of Metallic Packing for Pistons, Piston Valves, and Pump Buckets.
Year: 1888

page_text: Date of Application, 18th May, 1888
Complete Specification Left, 18th Feb., 1889
Complete Specification Accepted, 30th Mar.; 1889
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Metallic Packing for Pistons,
Piston Valves, and Pump Buckets.
I. ALEXANDER OLDHAM of Dukinfield in the County of Chester Engineer do hereby
declare the nature of this invention to be as follows:-
This invention relates first to the construction of the packing rings, the object
being to prevent them from flying off from the coiled spring as they are sometimes
liable to do when the piston cover is removed and secondly to the construction of the
coiled spring itself, the object being to enable the spring to be contracted for inserting
the same into and removing it from the cylinder, and also to expand the spring. when
it has become worn or weak.
In order to retain the packing rings firmly in their place upon the ends of the
coiled spring, and to prevent them from flying off when the piston cover is removed,
1 turn the inside circumference of the ring slightly dovetailed or tapering inwards
towards the centre (instead of its being either cylindrical or tapering outwards as
usually practised), so that the expansion of the coiled spring has a tendency to draw
the packing rings on, instead of throwing them off as beretofore.
The coiled springs I prefer to make from a narrow hoop of steel, brass, or other
suitable metal in the manner described in the Specification of Letters Patent
No. 4826 granted to me and dated 19th December 1877, and for the purposes of my
present invention I then turn each end of the coil inwards and I form the same into
a hook, loop, eye, lug or other similar device by means of which I attach to the two
ends a contracting spring, or a screw bolt or other device whereby when I wish to
from the
contract the spring for the purpose of introducing it into, or removing
cylinder, I can draw the two ends together and by these means contract the external
diameter of the coiled spring.
On the other hand should the spring have become weak or worn and require to be
expanded or strengthened the same may be done by means of an expanding spring so
applied as to force the ends of the coiled spring asunder and thus increase the
external diameter thereof.

page_text: Piston Valves, and Pump Buckets.
I, ALEXANDER OLDHAM of Dukinfield in the County of Chester Engineer 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 relates first to the construction of the packing rings, the object being
to prevent them from flying off from the coiled spring as they are sometimes liable to
do when the piston cover is removed, and secondly to the construction of the coiled
spring itself, the object being to enable the spring to be contracted for inserting the
same into, and removing it from the cylinder and also to expand the spring when
it has become worn or weak.
The nature of my said invention and the manner in which the same is to be
performed or carried into practical effect will be readily understood on reference to
the accompanying sheet of drawings and the following explanation thereof.
Fig. 1. on the annexed drawing is a vertical section of the packing rings and coiled
spring of a piston made according to my invention, and Fig. 2. is a partial section on
a larger scale showing the application thereof to a piston.
Figs. 3. 4 and 5 are sectional views of modifications of the above hereinafter
more particularly referred to.
a (on Fig. 2) shows part of the body of a piston and a part of the cover or
junk ring of the same. b (see also Fig. 1.) is the internal coiled spring, and
the external packing rings.
C, d are
In order to retain these packing rings c,
the coiled spring band to prevent them from flying off when the piston cover or junk
firmly in their place upon the ends of
ring b is removed I turn the inside circumference of the rings c, d (see Figs. 1 and 2)
slightly dovetailed or tapering inwards towards the centre (instead of its being either
cylindrical or tapering outwards as usually practised) so that the expansion of the
coiled spring b has a tendency to draw the packing rings c d on, instead of throwing
them off as heretofore.
The coiled springs I prefer to make from a narrow hoop of steel, brass, or other
suitable metal in the manner described in the Specification of Letters Patent
No. 4826 granted to me, and dated 19th December 1877, and for the purposes of my
present invention I turn each end of the coil inwards and I form the same into a
hook, loop, eye, lug or other similar device by means of which I attach to the two
ends a screw bolt e made in two parts with a right and left hand screw thread
(as shown) united by a long screw nut whereby when I wish to contract the
spring for the purpose of introducing it into, or removing it from the cylinder,
I can draw the two ends of the spring together and by these means contract the
external diameter of the coiled spring b..

page_text: On the other hand should the spring 6 have become weak or worn and requiro to
be expanded or strengthened, the same may be done by turning the nuts in the
reverse direction.
b
In the modification shown at Fig. 3. a spring 9 is employed to draw the ends of
the coil or spring 6 together and a rack his provided to hold the spring b either in
its contracted or expanded state.
Fig. 4 shows the use of a long coiled wire spring i for the same purpose which can
be contracted or expanded by means of the nuts and Fig. 5 shows tho application
of a single screw link I made in two parts united and expanded or contracted by the
single long nut m.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what 1
claim is :-
:-
First. The construction of the internal circumference of the packing rings of
pistons of a slightly dovetailed form or tapering inwards substantially in the manner
and for the purpose hereinbefore described and
Secondly. I claim the forming of the ends of the internal coiled spring of piston
packings into a hook, loop, eye, lug or other similar device and attaching thereto
screw bolts, links, springs or other similar devices whereby the said internal coiled
spring of the packing may be expanded or contracted as required substantially as
hereinbefore described and illustrated by the drawings annexed.
Dated this 16th day of Faban 1880
GEORGE DAVIES,
4, St. Ann's Square, Manchester,
Agent for the Applicant.