IMPROVEMENTS IN METALLIC PACKINGS FOR PISTON RODS.
Year: 1880

page_text: LETTERS PATENT to James Willard Preston, of Boston, in the County of
Suffolk, State of Massachusetts, U. S. of America, for the Invention of
"IMPROVEMENTS IN METALLIC PACKINGS FOR PISTON RODS.' A communication
to him by Thomas Tripp, of Stoughton, in the County of Norfolk, State of
Massachusetts. U.S. A.
ealed the 5th March 1880, and dated the 10th January 1880.
COMPLETE SPECIFICATION filed by the said James Willard Preston at the
Office of the Commissioners of Patents on the 10th January 1880.
JAMES WILLARD PRESTON, of Boston, in the County of Suffolk, State of Massa-
chusetts, U. S. of America. "IMPROVEMENTS IN METALLIC PACKINGS FOR PISTON
RODS." A communication by Thomas Tripp, of Stoughton, in the County of
Norfolk, State of Massachusetts, U. S. A.
My present improvements relate to a class of sectional metallic packings for
piston rods heretofore invented and patented by myself, the distinguishing features
of which consist in the employment of a sectional ring enveloping the rod, such
ring being composed of twin semi-rings capable of sliding upon one another in a
plane at right angles to the axis of the rod, and being maintained in a uniform
plane by suitable guides, and crowded up to the rod from opposite sides by means
which are controlled and adjusted from the outside of the cylinder head, an
important element in this class of packings being seen in the fact that it is suscep-
tible of lateral slip upon the cylinder head by and with any eccentric movements
of the rod should the latter become bent or "out of truo" from any cause.
In my
present packing I retain the semi-packing rings and the annular disc shown in my
Patent above mentioned, but discard the inclined plane or cams therein shown, and
substitute for them spiral springs which permit the rings to adapt themselves to
any irregularities or variations in the size or truth of the rod, which they enclose
while at the same time the entire device is moveable laterally with such rod, the
packing rings and springs being enclosed within an outer ring or hub, which in
turn is bolted to the annular disc before named, but not so tightly as to prevent
slip between the two, said springs exerting their stress between the hub and rings
to crowd the latter up to the rod, while to effectually "break joints" and prevent
leakage of steam between the parts I employ two sets or pairs of rings as against
one pair shown in my Patent.
The Drawings accompanying this Specification and illustrating my Invention
represent in in Figures 1 and 2 perspective views of a packing containing my

page_text: Invention, Figures 3 & 4 being cross sections, Figure 5, plan of thub with rings
removed; Figures 6 and 7 represent respectively an inner end view and longitudinal
section of the hub and packing rings A, A¹. In the above named Drawings A³
represents a stout ring or tubular hub or cylinder secured at one end to the outer
face of an annular plate or disc C by bolts a, a, in such manner that while no 5
steam can escape between them such slip of the two upon each other is permitted as
shall allow the packing device to follow any irregular lateral movement of the
piston rod, the disc C in its turn being securely bolted to the cylinder head or the
outstanding flange in which such cylinder head usually terminates.
The two pairs of sectional packing rings are shown at A, A', and B, B¹, the same 1
being received within opposite ends of the hub A³, and abutting end wise
against each other, and enclosing opposite sides of the piston rod, which is shown
at D.
The rings A, A', are formed with straight parallel sides, and are received and
slide within an enclosure E in one end of the hub A³, and are crowded up to the 1
piston rod from jopposito sides by springs F placed one behind each plate, and
exerting its stress between such plate and the bub. The rings B, B¹, are received
and slide within an enclosure G in the opposite end of the hub, but with their
parallel straight sides preferably arranged at right angles to those of the rings A, A',
in order to break joints, and the latter rings B, B¹, are so constructed as to be
guided by and slide upon one another in lieu of in guides within the hub as is the
case the rings A, A¹. To prevent escape of steam which might otherwise take
place between the inner ends of the rings A, A¹, I form the enclosure G larger than
said rings, thus providing an offset or shelf H which is covered by the rings B, B¹,
thus furnishing a joint to prevent leakage of steam between the rings A, A', and
about the piston rod.
The spring for advancing the rings B, B¹, up to the piston rod are shown at I, I,
as arranged, and operating in a manner similar to the springs F, F, before named.
The hub A may be an integral casting, but for convenience of manufacture I form
it of two portions or semi-rings J, J, bolted securely together by bolts, as shown in
Figures 1, 2, and 5 of the Drawings, the semi-rings of the hubs being represented
as bolted immovably together, with no slip or play toward and away from the
piston rod, the only play in this respect being between the packing rings
A, A¹, B, B¹.
I propose, however, in some classes of packing placing a block of metal between
the abutting ends of the two portions of the limb, and in the event of failure or
breaking of any one or more of the springs these blocks may be removed, and the
two portions of the rings crowded up to, and so as to tightly enclose the piston rod.
In this manner I am enabled to provide against breaking of the springs and
consequent leaking of steam.
K in the Drawings represents an annular plate secured to the outer end of the
hub to prevent escape of the packing rings at this point.
In Figures 6 and 7 of the Drawings, which respectively represent an inner end
view and longitudinal section of the hub, and packing rings A, A', I have shown
an additional means of security against leakage of steam at the point where the
piston rod emerges from the cylinder head. In this case I employ two crescent
shaped or semicircular plates a¹, a¹, the inner faces or sides of which are sections of
a circle equal to the circumference of the piston rod, consequently such plates
surround the rod and are let into pockets 61, 61, created in part in the ends of the
packing rings A, A', and in part in the end of the hub in order that the outer
surface of the whole may be flush, the plates a¹, a¹, being so arranged that they
overlap or cover the adjacent ends of the packing plates A, A¹, in order to break
the joints between such ends and the piston rod, and prevent access of steam by
these joints.
Outside of the plates a¹, a¹³, and snugly encompassing the piston rod I place a
flat ring d which covers the inner faces of the plates a¹, a¹, and the ends of the
rings A, A', and serves to prevent steam from the cylinder getting access to such

page_text: rings. The ring is let into an annular recess or rebate created in the outer end
of the annular plate C before named as serving to confine the hub and its accessories
to the cylinder head, the ring d¹ being prevented from play longitudinally of the
of the piston rod, but being susceptible of lateral play within the plate C in order to
follow any irregular lateral movements of the rod.
In the event of using the segmental plates a¹, a', the packing rings B, B', may
be dispensed with, and also the shelf or shoulder H in the bore of the hub, and the
rings A, A', would in this event be of equal length with said hub, as shown in
Figure 7 of the Drawings.
It will be seen that the plate a¹, a', follow the movements of the packing rings
A, A', as the latter close upon the piston rod, except that the movements of the two
are at right angles to each other, hence any movement of the rings by reason of
wear or from any irregularity in the shape of the rod are followed by the plates
and a tight joint about the rod secured.
First. The packing rings A, A¹, B, B¹, in combination with the hub or enclosing |
ring A, and annular plate or disc C, substantially as described.
Second. The rings A, A, B, B¹, in combination with the hub A² and disc C, and
as pressed up to the piston rod by springs suitably applied, substantially as and for
purposes herein before described.
Third. The construction of the hub and packing rings, as described, whereby
the offset or ledge H is created in the hub and one pair, viz., B, B', of rings, covers,
or breaks, the joint between the first named rings and said ledge, substantially as
hereinbefore described and for purposes stated.
Fourth. The combination with the two portions of the hub of the packing rings
when the parallel straight faces of the latter are arranged practically at right angles
to each other, substantially for purposes stated.
Fifth. In combination the hub or cylinder A², rings A, A¹, B, B', disc C, and
cap or plate K, the hub and cap being secured to the disc and the latter bolted to
the cylinder head, and the whole operating substantially as stated.
Sixth. In combination with the rings A, A¹, and hub A², the plates a¹, a¹, serving
to break the joints between the opposite ends of the said rings and prevent passage
of steam between them and the piston rod, substantially as explained.
Seventh. The rings d, in combination with the hub A² and annular plate C,
under the arrangement and operating substantially as described.
Eighth. The ring d', in combination with the hub A³, annular plate C, and
segmental plates a, a, substantially as explained.
Ninth. In metallic rod packings containing sectional rings encircling the rod the
plates a, a, in combination with the rod and sectional rings, the plates moving up
to the rod in a direction at right angles to that followed by the rings, and the
whole being essentially as and for purposes stated.
Tenth. The construction of the right angular plate and hub, as shown in Figure 8
of the accompanying Drawings.
In witness whereof, I, the said James Willard Preston, have hereunto set
my hand and seal, this 18th day of December 1879.
TARS
זגBCAסס תסוזזזIr