Improvements in Metallic Packing Devices for Piston Rods, Valve Rods, and the like.
Year: 1895

page_text: Date of Application, 18th Mar., 1895
Complete Specification Left, 18th Dec., 1895-Accepted, 18th Jan., 1896
PROVISIONAL SPECIFICATION.
Improvements in Metallic Packing Devices for Piston Rods, Valve
Rods, and the like.
I, EDWARD CUNNINGHAM of 71 Paradise Street, Liverpool in the County of
Lancaster, Marine Fireman, do hereby declare the nature of this invention to be
as follows:-
This invention has for its object a metallic packing device for piston rods, valve
rods and the like. It is designed to form a steam-tight contact without having to
use a hemp or other like packing and a stuffing box.
In carrying my invention into effect, the plan I prefer is to provide a box
attached to the end of the cylinder through which passes the rod. In this box
are located rings of brass or other suitable metal, either cast to possess elasticity in
themselves or cut into segments and adapted to break joint. They are provided
with an oil space between. The adjacent faces of these rings are chamfered at
intervals to receive wedges adapted to slide radially and to press the rings against
the internal faces of the box and onto the piston rod, so as to form a steam-tight
contact. The wedges are held permanently against the rings by means of a spring,
or in any other suitable manner, and the pressure of these springs is regulated by
means of a screw and lock nut mounted in a saddle.
The mode of action is as follows-
To adjust the metallic packing and make a perfectly steam-tight joint, the
screws are turned to compress the springs. By this means the wedges press the
packing rings in opposite directions against the internal faces of the box and
against the rod, thus forming a steam-tight contact and preventing any possibility
of steam escaping. The space between the rings provides a convenient means for
lubricating the rod.
I have described one way in which my invention may be carried into effect, but
it is obvious that having once given the general idea, various alterations may be
made, thus, for example, any suitable number of these packing rings may be
employed with a corresponding number of wedges, also various other arrangements
may be adopted for operating the wedges and pressing the rings radially inwards
against the rod and laterally against the box so as to prevent leakage of steam
from the cylinder or elsewhere. Furthermore it will be obvious that the invention
is useful for all kinds of reciprocating rods, where a steam-tight or like contact is
required.
Dated this 14th day of March 1895

page_text: Improvements in Metallic Packing Devices for Piston Rods, Valve
Rods, and the like.
I, EDWARD CUNNINGHAM of 71 Paradise Street, Liverpool in the County of
Lancaster, Marine Fireman, 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 has for its object a metallic packing device for piston rods, valve
rods and the like. It is designed to form a steam-tight contact without having to
use a hemp or other like packing and a stuffing box.
The invention will be understood from the following description, reference being
had to the accompanying drawings, in which,
Figure 1 is a longitudinal section on the line x y of my improved packing as
fitted for example to a piston rod of a cylinder;
Figure 2 a cross section.
In these figures, A is a box bolted to the end of the cylinder, through which
passes the rod B.
In this box is located a pair of segmental rings C C₁ of brass
or other suitable material, also solid rings D on each side of the rings C C¹, the
rings D being interposed between the rings C C¹ and the internal ends of the box.
The two rings C C' may be provided with an oil space between if so desired, but
in practice I find this unnecessary. The faces of the rings C C' are chamfered at
intervals to receive wedges E E adapted to slide radially and to press both the
rings C C against the lateral faces of the box. Furthermore the wedges E press
the ring C, and the the wedges E' press the ring C¹ radially on to the piston rod
so as to form a steam-tight contact. The wedges within the box are held firmly
against the rings by means of springs F arranged on the outside of said box or in
other suitable manner, and the pressure of these springs is regulated by means of a
screw G and lock nut H mounted in the saddle I. By this arrangement the springs
with their screws and locking nuts are always accessible, so that they can be
adjusted without taking to pieces any of the parts, and moreover the springs are
not in close proximity to the rod where the heat is very considerable, and liable to
injure the temper of the springs, but are some little distance therefrom and wholly
exposed to the air. The adjacent ends of the segmental rings C C' are chamfered
where they abut, the two larger segments of each ring keeping the smaller
segments thereof in place so that the latter cannot separate from the larger ones.
By this means the radial pressure of the springs and wedges on the two larger
segments of each ring will press the two smaller segments with equal pressure on
the rod, and hence all the segments of the rings have perfect freedom, while
each segment is pressed with equal pressure radially against the rod. The rings D
allow the piston rod a certain amount of lateral play without in any way injuring
the packing or spoiling the steam-tight contact..
The mode of action is as follows:-
To adjust the metal packing and make a perfectly steam-tight joint, the screws G
are turned to compress the springs F. By this means the wedges E E' press the
packing rings C Ci in opposite directions against the rings D and internal faces of
the box A, the wedges E moreover pressing the rings C and the wedges E¹
pressing the rings C¹ radially against the rod, thus forming a steam-tight contact
and preventing any possibility of steam escaping. The space between the rings
when provided affords a convenient means for lubricating the rod.
I have described the above way in which my invention may be carried into
effect, but it is obvious that having once given the general idea, various alterations
may be made; thus for example any required number of these packing rings may

page_text: be employed with a corresponding number of wedges, also various arrangements may
be adopted for operating the wedges and pressing the rings radially inwards against
the rod and longitudinally against the box so as to prevent leakage of steam
from the cylinder or elsewhere. Furthermore it will be obvious that the invention
is useful for all kinds of reciprocating rods where a steam-tight or like contact is.
required.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what I
claim is :-
1. The improvement in metallic rod and spindle packing, which consists in
forming them of one or more pairs of segmental rings enclosed within a box,.
through which passes the rod to be packed, in combination with wedges arranged
between the rings of the packing in such a manner that when pressed radially
they will force the packing rings longitudinally in opposite directions towards the
internal faces of the box and radially against the rod, whereby a steam-tight.
contact is produced substantially as described.
2. The rod and spindle packing in which there are one or more pairs of segmental
metallic packing rings arranged within a box, and four springs to each pair
arranged on the outside of said box pressing the packing rings by means of wedges
in a radial direction against the rod as well as longitudinally, substantially as and
for the purpose described.
3. In metallic packing for rods in which segmental packing rings are compressed
against the rod by spring pressure, the special arrangement whereby the segmental
parts of the ring are held together around the rod so that they cannot separate
beyond a certain degree, or one segment of the ring apply a greater pressure on
the rod than another segment, such arrangement allowing perfect freedom to the
parts of the ring being pressed with equal pressure against the rod, substantially
as described.
4. The use in combination with segmental packing rings that are pressed against
the rod by spring pressure, of solid rings D, so formed and arranged as to allow
the rod a certain amount of lateral play without injuring the steam-tight contact
substantially as described.
5. The general combined arrangement and construction of parts forming my
improved metallic packing for reciprocating rods where a steam-tight or like.
contact is required, substantially as set forth.
Dated this 17th day of December 1895.
WM. P. THOMPSON & Co.,
Of Liverpool, Manchester, Birmingham, and London, Patent Agents.