Metallic Packings for Piston and Valve Rods and the like.
Year: 1898

page_text: Metallic Packings for Piston and Valve Rods and the like.
I, JOSEPH BUTTERWORTH, of 131, Station Road, Pendlebury, in the County of
Lancaster, Engineer, do hereby declare the nature of this invention to be as
follows:-
-
In Patent 11,231/92, spiral springs are shown encircling metallic blocks and
pressing them to the rod. These are open spiral springs having the spaces between
the coils equal to the thickness of the wire of which the springs are made. In the
present invention, it is proposed to make the springs close lapped, or nearly so,
for the greater part of their length, but to leave them open at one or both ends
so that they may be screwed into each other and shortened or lengthened as shown
in the above mentioned patent. Where the springs are coiled open at one end
only, they are secured at the other end by forming the latter into a hook or an eye.
By this means, a greater number of coils can be formed in the spring, when a
heavier section of steel may be used and the spring still have no greater resistance
per unit of elongation.
The end springs, or those which press on the ends of the metallic blocks keeping
the joints at right angles to the axis of the rod steamtight, are liable to a cross
strain when the piston rod is working out of line, as the spring bush in which the
springs work is a fixture, or, if made loose, tends to become fixed under the pressure.
In order to obviate this strain, a washer which is interposed between the metallic
blocks and the end springs is made sufficiently slack on the rod to allow of the
lateral motion of the latter, while the outside of the washer is made to fit the inside
of the stuffing box, or casing, In addition, the holes in which the springs rest in
the spring bush are made slightly taper so as to allow of a little lateral motion of
the springs. The washer is also made with a thin cylindrical rim projecting
between the springs and the rod so that in case one of the springs broke, the
broken part could not get to the rod and mark it; or a rim may be formed on, or
attached to the spring bush for a similar purpose.
Where the space at disposal admits of it, a groove may be formed in the spring
bush sufficiently deep to bury the end springs when compressed, a projection being
formed on the washer or interposed between it and the springs to force the latter
into the groove; or, a groove may be formed in the washer and a projection on
the spring bush for the same purpose.
For smaller rods, or for rods working in liquids or gases where the use of springs
is not advisable, the metallic blocks are made conical in shape and in halves, the
joints between the blocks as seen in cross section being lines drawn tangent to the
rod on opposite sides of the latter and in opposite directions. The two halves are
thus able to close on the rod and compensate for wear by sliding on each other at
their joints. At least two conical, rings as above are used, the bases of the cones
(if flat) being pegged or otherwise secured so that the joints in the two rings are
at right angles.

page_text: The bases of the cones may also be made slightly conical, in which case a metal
washer would be inserted between them, coned internally to suit both bases. The
blocks may be pressed to the rod by a backing of soft packing forced against them
by the pressure of a gland in the ordinary way for temperatures and pressures up
to about 100 lbs. steam pressure.
For low temperatures such as in air pumps and the like, the backing may be
made of rubber or a similar elastic substance.
The metallic blocks are made preferably of white metal, but where high pressures
and temperatures have to be withstood, the conical ring, which is nearest to the
steam may be made of gun metal or other metal which will stand the heat, while
the outer one may be made of white metal. In cases where extremely high
temperatures have to be withstood, such as superheated steam, both rings may be
made of gun metal as above. In the latter case, the conical rings may be forced
to the rod by means of metal rings split in a similar manner to, and coned
on the inside to fit them, but a ring of soft packing would be required at the outer
end in this case to keep the packing rings tight till they get thoroughly bedded
to the rod.
Dated this 2nd day of February 1898.
Metallic Packings for Piston and Valve Rods and the like.
I, JOSEPH BUTTERWORTH, of 141, Station Road, Pendlebury, in the County o
Lancaster, Engineer, do hereby declare the nature of this invention and in wha
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement:-
In Patent 11,231/92, spiral springs are shown encircling metallic blocks and
pressing them to the rod. These are open spiral springs having the spaces between
the coils equal to the thickness of the wire of which the springs are made. In the
present invention it is proposed to make the springs close lanned, or nearly so,
for the greater part of their length, but to leave them open at one or both ends
so that they may be screwed into each other and shortened or lengthened as shown
in the above mentioned patent. Where the springs are coiled open at one end
only they are secured at the other end by forming the latter into a hook or an eye.
By this means a greater number of coils can be formed in the spring, when a
heavier section of steel may be used and the spring still have no greater resistance
per unit of elongation.
The end springs, or those which press on the ends of the metallic blocks keeping
the joints at right angles to the axis of the rod steamtight, are liable to a cross
strain when the piston rod is working out of line, as the spring bush in which the
springs work is a fixture, or if made loose, tends to become fixed under the pressure.
In order to obviate this strain a washer which is interposed between the metallic
blocks and the end springs is made sufficiently slack on the rod to allow of the
lateral motion of the latter, while the outside of the washer is made to fit the inside
of the stuffing box or casing. In addition, the holes in which the springs rest in
the spring bush are made slightly taper so as to allow of a little lateral notion of
the springs. The washer is also made with a thin cylindrical rim projecting
between the springs and the rod so that in case one of the springs broke, the
broken part could not get to the rod and mark it; or a rim may be formed on, or
attached to the spring bush for a similar purpose.

page_text: Where the space at disposal admits of it, a groove may be formed in the spring
bush sufficiently deep to bury the end springs when compressed, a projection being
formed on the washer or interposed between it and the springs to force the latter
into the groove; or a groove may be formed in the washer and a projection on
the spring bush for the same purpose.
For smaller rods, or for rods working in liquids or gases where the use of springs
is not advisable, the metallic blocks are made conical in shape and in halves, the
joints between the blocks as seen in cross section being lines drawn tangent to the
rod on opposite sides of the latter and in opposite directions. The two halves are
thus able to close on the red and compensate for wear by sliding on each other at
their joints.
At least two conical rings as above are used, the bases of the cones (if flat) being
pegged or otherwise secured so that the joints in the two rings are at right angles.
The bases of the cones may also be made slightly conical in which case a metal
washer would be inserted between them, coned internally to suit both bases. The
blocks may be pressed to the rod by a backing of soft packing forced against them
by the pressure of a gland in the ordinary way for temperatures and pressures up
to about 100 lbs. steam pressures.
For low temperatures such as in air pumps and the like, the backing may be
made of rubber or a similar elastic substance.
The metallic blocks are made preferably of white metal, but where high pressures
and temperatures have to be withstood, the conical ring, which is nearest to the
steam may be made of gun metal or other metal which will stand the heat, while
the outer one may be made of white metal. In cases where extremely high
temperatures have to be withstood such as superheated steam both rings may be
made of gun metal as above. In the latter case the conical rings may be forced
to the rod by means of white metal rings split in a similar manner to, and coned
on the inside to fit them, but a ring of soft packing would be required at the outer
end in this case to keep the packing rings tight fill they get thoroughly bedded
to the red.
In order that the invention may be clearly understood reference is made to the
drawings herewith. Figures 1 and 2 Sheet 1 represent the packings fixed to a steam
cylinder cover R through which the piston red A works. Figure 1 is half in
section through the centre of the red and half an external view. Figure 2 is a
cross section of Figure 1 at M, N.
The springs Zincircling the metallic blocks are shown (Figure 2) close-lapped
for the greater part of their length but open at S where they are screwed into each
other, and hooked and eyed at If to connect them at their other ends.
The end springs T fit in holes made to receive them in bush Y and press against
the washer X which is bored large enough to allow of the oscillation of the rod
and made to fit the inside of the casing C. The holes in bush Y to receive the
springs T are made slightly taper so as to allow of a little lateral motion of the
springs. The washer X is also made with a thin rim as shown projecting between
the springs T and the rod A or a similar rim might be formed on the spring bush Y
for the same purpose.
Where the space at disposal admits of it a groove may be formed in the spring
bush (see Figure 3 Sheet 2) and a projection formed on the washer X so as to
bury the springs in the groove when compressed as shown, or a similar groove may
be formed on the washer and a projection on the spring bush for the same purpose.
For smaller rods and where the use of springs is not advisable the blocks W
and Ware made conical in shape (as shown Sheet 2 Figures 4 and 5) and in
halves. The joints between the blocks W as seen at 0 Figure 5 in cross section
are lines drawn tangent to the rod A allowing the blocks to slide on cach other
as they close on the rod to compensate for wear.
At least two rings W and Ware used, the bases being pegged or otherwise
secured as shown at P Figure 5 so that the joints in the two rings are at right
angles is shown in dotted lines.

page_text: The blocks are pressed to the rod by a backing of soft packing inserted at Q
Figure 4 and forced against them by the pressure of a gland L in the ordinary
way for steam pressures up to 100 lbs. per square inch. For low pressures such as
in air pumps the backing Q may be of rubber or other elastic substance. In cases
where extremely high temperatures have to be withstood such as in superheated
steam both W and W may be made of gun metal.
may be forced to the rod A by means of metal rings fitted at Q and split like W
In the latter case Wand WI
and W, and also coned on the inside to fit them, but a ring of soft packing would
have to be interposed between the rings and the gland L in this case.
Having now particularly described and ascertained the nature of
invention and in what manner the same is to be performed I declare that what I
claim is:-
my said
-
1st. Coiling the springs Z closelapped for the greater part of their length, and
openlapped for the remainder, as, and for the purpose herein described.
2nd. Forming a thin cylindrical rim or collar inside the washer X
bush Y Fig. 2 as and for the purpose herein described.
3rd. Forming a recess in bush Y or in washer X as shown in Fig.
for the purpose described.
spring
as and
4th. The packing as shown in Figs. 4 and 5 consisting of at least two conical
metal rings each in halves and cut as shown in Fig. 5; the rings W & W₁ being
pegged or otherwise secured to each other so that the joints in the two rings are
at right angles as and for the purpose described.
2
Dated this 1st day of November 1898