AN IMPROVED PACKING FOR PISTON RODS, VALVE STEMS, AND OTHER SIMILAR USES
Year: 1874

page_text: PROVISIONAL SPECIFICATON left by Bristow Hunt at the Office of
the Commissioners of Patents, with his Petition, on the 1st
September 1874.-A communication from abroad by Phillip
William Richards, of Boston, Massachusetts, Machinist, Frank
Eleazer Crain, Merchant, and John Everitt, Manufacturer, both of
Brookline, Massachusetts, in the United States of America.
I, BRISTOW HUNT, of Serle Street, Lincoln's Inn, in the County of
Middlesex, Gentleman, do hereby declare the nature of the said Inven-
tion for "AN IMPROVED PACKING FOR PISTON RODS, VALVE STEMS, AND OTHER
SIMILAR USES," (a communication to me from abroad by Phillip William
Richards, of Boston, Massachusetts, Machinist, Frank Eleazer Orain,
Merchant, and John Everitt, Manufacturer, both of Brookline, Massa-
chusetts, in the United States of America), to be as follows:-
This Invention relates to certain new and useful improvements in
metallic packing for piston rods, valve stems, and other uses, and has
for its principal object the providing a durable, efficacious, and
economical packing which can be readily applied within a stuffing box to
prevent the leakage of steam, water, or other fluid, and can be easily
and conveniently adjusted and managed by any person of ordinary
ability.

page_text: The improved packing is composed of two outer cup-like rings or
heads, each formed in two sections held together by mortises and tenons,
and between these rings are contained layers or rings formed by circular
segmental metallic blocks bevilled and otherwise shaped, and arranged
to break joints with and fit one layer against the other in such a manner
as to take up the entire wear of the segments, and cause the bearing of
the segments to be at all times towards the rod or stem, and against the
head or cup-like ring in the bottom of the stuffing box so as to
effectually prevent leakage, the other head or cup-like ring having a
free action on the rod or stem to follow up the wear of the said
segmental blocks.
By merely screwing up the gland as for the adjustment of ordinary
fibrous packing, this improved packing may be readily adjusted and
conveniently managed without the requirement of skilled knowledge,
and with little trouble or labour. As the pressure brought to bear on one
of the outer cup-like heads which acts freely on the rod or stem causes
one layer of blocks to impinge tightly against the other, and on the rod
or stem so as to take up the wear at all times and prevent leakage.
The formation of the blocks and that of the angles of their bevils are
such as to press the blocks inward or downward, the ends of the inner
rims of the several segments abutting firmly one against the other, and
thus wearing at an angle; their close impingement at all times is ensured
to prevent leakage at the edges, while leakage at other portions is pre-
vented by the arrangement of the several parts of the packing which
cover and break joints with one another, so as safely to protect them
and ensure great durability.
It is well known that hemp and other fibrous packing is apt with
time to lose its flexibility, becoming so hard and rigid in its action as to
cut the rod or stem, and thereby often necessitating the removal,
returning, and replacing of the latter. These objections are obviated by
this improved metallic packing which is flexible in its action and of
durable material, and arranged to be readily adjusted as above fully
described.