The first claim in letters patent No. 121,933, granted to the
Buffalo Dental Manufacturing Company as assignee of George B. Snow
June 11, 1872, for a new and useful improvement in steam bell
ringers is limited to a combination in which the piston and piston
rod are detached from each other, and is not infringed by the use
of steam bell ringers constructed and operated in conformity to the
drawings and specifications of letters patent granted August 20,
1874, to Charles H. Hudson for a new and useful improvement in
steam bell ringing apparatus.
This was a bill in equity to restrain an alleged infringement of
letters patent. Decree dismissing the bill, from which the
complainants appealed. The case is stated in the opinion of the
Court.
MR. JUSTICE MATTHEWS delivered the opinion of the Court.
The appellants, who were complainants below, filed their bill in
equity, August 7, 1882, against the defendant, to restrain the
alleged infringement of letters patent No. 127,933, granted to the
Buffalo Dental Manufacturing Company, as assignee of George B.
Snow, on June 11, 1872, for a new and
Page 121 U. S. 618
useful improvement in steam bell ringers, the Buffalo Dental
Manufacturing Company being a joint-stock association under the
laws of the State of New York, of which the appellants were the
sole officers, directors, shareholders, associates, and persons in
interest. The specifications, with drawings annexed, of this patent
are as follows:
"Specification describing certain improvements in steam bell
ringing apparatus, invented by George B. Snow, of Buffalo, in the
County of Erie, State of New York."
"This invention relates to the construction of a steam bell
ringer in such a manner as to prevent any apparent leakage, either
of water or steam, without resorting to the use of stuffing boxes,
and also to cause the admission and release of the steam directly
by the motion of the piston, and without the use of any
intermediate parts between the piston and valves."
"Referring to the annexed drawing, Figure 1 is an elevation of
the device as applied to the bell of a locomotive. Fig. 2 is a
vertical section of the steam cylinder on the plane
a b on
an enlarged scale."
"A is a single-acting steam cylinder, connected to the crank B
on the bell yoke by the slotted rod C. This rod should be of such a
length that the piston G will be forced to the bottom of the
cylinder as the crank B passes its lower center, the slot through
which the crank pin passes being long enough to allow the crank to
pass its upper center freely, notwithstanding the disproportion
between the throw of the crank B, and the length of stroke of the
piston rod D. The piston G is disconnected from its rod D to
prevent any lateral strain's being communicated to it, thereby
decreasing to some extent the wear of the piston in the cylinder.
The piston should be considerably longer than its length of stroke.
The piston rod D passes through a sleeve in the cylinder cover I,
which should be long enough to steady it and act as a guide and is
limited in its upward motion by the collar
d. E is a
conical exhaust valve, seating upward against the bottom of the
piston G. F is the steam valve, also conical, and seating upward,
containing within itself the tail of the exhaust valve E,
Page 121 U. S. 619
such an amount of motion being permitted between the two that
the steam valve F will be raised to its seat, and the exhaust valve
E be opened as the piston approaches the upper end of its stroke.
Exhaust passages M
m are formed in the piston G which
communicate with the holes
m' in the side of the cylinder
by means of annular grooves turned in the side of the piston; the
openings
m' being of such a number and so disposed as to
ensure a constant communication with the passage M. The thimble H
forms an annular space around the cylinder, from which the steam
escapes through the passage O. If the piston is closely fitted, it
will wear a long time with very little leakage, and what there may
be will be caught in the annular grooves in the side of the piston,
and passed at once through the exhaust passages
m', thus
preventing any leakage around the piston rod D. It is advisable to
use a packing of a single ring at the lower part of the piston, not
so much to avoid leakage as to sustain the piston at the upper end
of its stroke by the elasticity of the ring until it is brought to
the bottom of the cylinder by the return swing of the bell."
"The bell being set in motion, the crank B drives the piston to
the bottom of the cylinder, closing the exhaust valve and forcing
open the steam valve, admitting steam to the cylinder from the
space S. As the piston is driven upward, the exhaust valve is
carried with it, and as the piston approaches the end of its
stroke, the steam valve is also raised to its seat, after which the
exhaust valve is opened. As the pressure is relieved, the exhaust
valve drops, leaving the passage M entirely clear during the return
stroke, which is made by the momentum of the bell on its return.
The arrangement of valves shown is not essential, as the exhaust
valve may be placed in a cavity in the body of the cylinder opening
into the exhaust passage, and both the steam and exhaust valves be
closed by the direct impulse of the steam, the openings
m'
being made low enough in the cylinder to allow the piston to pass
them at the upper end of the stroke, or, by using a piston in the
form of an inverted cup, the steam and exhaust may be worked
through openings in the side of the piston and cylinder, the
expansion of the steam "
Page 121 U. S. 620
image:a
Page 121 U. S. 621
image:b
doing the work. The disadvantage of the first of these plans is
that the valves are closed so violently that they soon wear out; of
the second, the difficulty of getting rid of water of
condensation.
"Having thus fully described my device, I claim as my invention
--"
Page 121 U. S. 622
"1. The combination of the cylinder A, piston G, piston rod D,
slotted rod C, and crank B, when constructed and operated
substantially as described."
"2. The combination of the valves E and F, both seating upward,
with the piston G, and passages
M m m' for the purpose of
admitting steam to and exhausting it from under the piston G,
substantially as described."
The infringement alleged is of the first claim only, and
consists in the use by the defendant below of steam bell ringers
constructed and operated in conformity to the drawings and
specifications of letters patent granted August 25, 1874, No.
154,394, to Charles H. Hudson for a new and useful improvement in
steam bell ringing apparatus. The specifications and illustrative
drawings of that patent are as follows:
"
To All Whom It may Concern:"
"Be it known that I, Charles H. Hudson, of the City and County
of Dubuque, Iowa, have invented a new and useful improvement in
steam bell ringing apparatus, of which the following is a
specification:"
"This invention relates to steam engines designed for ringing
bells on locomotives and in other places, and consists in the
construction and arrangement of parts, as hereinafter described,
and specifically indicated in the claim."
"In the accompanying drawings, Figure 1 represents a vertical
section of Fig. 2 on the line
x x, and Fig. 2 is a
horizontal section taken on the line
y y, Fig. 1."
"Similar letters of reference indicate corresponding parts."
"This bell ringing engine may be worked with either steam or
air."
"A is the cylinder, B the piston. C is the piston rod. D is the
valve ring. E is a rod which is hinged to the piston rod at the
point F. This rod, E, slides in the tube G, which is attached to
the bell crank. This connection is such that the lower end of the
tube G will be at the shoulder H, when the bell crank is at the
lowest point, and the piston at the bottom of the stroke. The
movement of the tube upon the rod E will allow the bell to be
turned over and the bell crank to go to its highest point freely,
while the piston is at the lowest point. "
Page 121 U. S. 623
image:c
"I is the exhaust port; J, the inlet port. The valve ring D is
so arranged in regard to the ports that the movement of the piston
to the lowest point moves the valve ring down, and closes the
exhaust and opens the inlet port. When the piston moves to the
other end of the stroke, the ring is moved in the
Page 121 U. S. 624
other direction, and the inlet is closed and the exhaust is
opened. K is the inlet passage. L is the exhaust passage.
m is a small opening into the exhaust passage to allow any
steam which may pass the piston to escape. O O are ports or
passages in the lower head of the double piston to permit the steam
(or air, if used) to act against the lower head of the
cylinder."
"When the bell is in motion, the bell crank will press the tube
down on the rod and force the piston to the bottom of the stroke
and thereby close the exhaust and open the inlet ports. When the
crank has passed the center of the stroke, the steam admitted by
the movement of the valve ring presses the piston up and throws up
the bell. The tube connection allows the bell crank to move freely
upward after the piston has reached the end of its stroke, cut off
the steam, and open the exhaust port. The return swing of the bell
is followed by the same action of the parts. N is a small set-screw
in the tube G, the end of which enters a groove, or acts against a
flat side of the rod E to prevent the piston rod from turning. Any
other suitable device may be adopted for the purpose. I do not
claim broadly the combination of a valve ring with a piston and
cylinder for cutting off admission and escape of steam alternately,
but, having thus described my invention, I claim as new, and desire
to secure by letters patent, in combination with the vertical
cylinder A, having inlet and exhaust ports K J and I L
m
the double piston B, having openings or passages, O O in its lower
head, and the valve ring D, arranged below the upper head thereof,
as shown and described, to operate as specified."
The question of infringement turns upon the construction to be
given to the first claim of the patent sued on, to determine which
it is necessary to consider the state of the art at the time of its
date. This is shown by a prior patent issued to Snow, No. 11,307,
dated July 11, 1854, and which had expired before the granting of
the patent sued on.
The specifications and accompanying drawings of that patent are
as follows:
Page 121 U. S. 625
"
To Whom It may Concern:"
"Be it known that I, G. B. Snow, of Buffalo, in the County of
Erie and State of New York, have invented a new and useful method
of employing steam to ring the bells of locomotives,"
image:d
"and other bells, and I do hereby declare that the following is
a full, clear, and exact description of the same, reference being
had to the accompanying drawings forming part of this
specification, in which Fig. 1 is a longitudinal vertical section
of the apparatus I employ applied to a bell. "
Page 121 U. S. 626
"Fig. 2 is a plan of the same."
"Similar letters of reference indicate corresponding parts in
both figs."
image:e
"My invention relates to the application of steam power to the
ringing of the bell, and it consists of a novel combination and
arrangement of a direct acting engine with the bell in such a
manner that the bell, being swung by the engine in one direction,
is allowed to swing in the opposite direction by its own gravity
and momentum, and is caused thus continuously, automatically, to
work with the same freedom, but greater
Page 121 U. S. 627
regularity and consequent increased clearness of note, as is
obtained by the ordinary manual process of ringing."
"To enable others to make and use my invention, I will proceed
to describe its construction and operation:"
"A in the drawing is the bell, which is suspended by a yoke B of
the usual kind, furnished with a lever C for the purpose of ringing
it. D is the steam cylinder, which is placed in a suitable position
for its piston E to connect with the yoke, and by its movement to
swing the bell. The bore of the cylinder for a locomotive engine
would require to be of a diameter about one and a quarter (1 1/4)
inches, and of a length about four and one-half (4 1/2) inches. The
piston rod F works through a stuffing box at one end of the
cylinder, which is closed, and it carries a crosshead C, which
works on a fixed guide rod H. The other end of the cylinder is open
to the atmosphere. At the closed end of the cylinder there is a
valve box or steam chest K which receives a steam pipe
c
from the boiler, and has a steam port
a leading to the
cylinder, and an exhaust port
b leading to the atmosphere.
The slide valve I, which this valve box contains, has a rod
e passing through a stuffing box, and furnished with two
tappets
d d' between which it is embraced by a fork on the
cross-head G. These tappets are adjusted so that the fork shall
come in contact with them to open or close the steam port at the
proper time, and thus regulate the movement of the piston. The
cross-head is connected with the lever C of the bell yoke B by a
chain J."
"Fig. 1 of the drawing represents the steam port
a
open, and the steam acting on the piston, which has nearly
terminated its stroke, owing to the cross-head having come in
contact with the tappet
d' and being about to move the
valve to close the steam port and open the exhaust port. As soon as
the steam is shut off and the momentum of the bell is spent, the
latter will swing back, drawing with it the piston, until the
cross-head strikes the tappet
d and moves the valve far
enough to open the steam port and close the exhaust port, when the
motion of the bell will be again reversed. The motion which is thus
given to the bell is precisely similar to that produced in ringing
by hand, and could not
Page 121 U. S. 628
be produced by the direct application of steam power to swing it
in both directions, which must produce too positive a motion and
could not allow it to swing with the same freedom as when the power
is only applied in one direction and the bell is allowed to return
under the influence of gravitation alone."
"I do not claim of itself as new ringing bells by the
application of steam power, as such, in a positive manner, by
rigidly connecting the engine with the bell in both directions of
the swing of the latter, has before been done, nor do I claim the
several devices herein named individually as new; but I do claim as
new and useful, and desire to secure by letters patent, the manner
herein described of ringing the bell by the application of steam
power and the gravity and momentum of the bell combined by means of
the direct acting engine attached by chain or other equivalent
mechanical device to the bell, and arranged, combined, and
operating with the bell as specified, and so that the bell is swung
in one direction by the engine, and then let loose or free to swing
back in the opposite direction by its own gravity and momentum to
produce the ring or sound, and the steam alternately admitted to
and exhausted from the engine by the action of the engine and
movement of the bell combined, substantially as specified, and
whereby the same freedom in the swing of the bell to produce a long
and clear sound, as is produced by the ordinary manual process, but
with greater regularity, and consequent increased clearness of
note, is automatically obtained, as herein set forth."
On final hearing in the circuit court, the bill was dismissed
for the reasons stated by the circuit judge in his opinion, as
follows:
"Although the complainants' patent of June 11, 1872, suggests
the principal and the most valuable parts of the combination found
in the defendant's steam bell ringer, the plain and explicit
language of the specification requires a construction of the first
claim which will enable the defendant to escape liability as an
infringer. The first claim must be limited to a combination in
which the piston and piston rod are detached from each other. "
Page 121 U. S. 629
"The patentee doubtless considered that the detachment of the
piston and piston rod would assist materially in effecting one of
the two expressed objects of his invention,
viz., the
prevention of leakage of steam. To prevent the escape of steam
around the piston rod, he proposed to confine the steam behind the
piston instead of introducing it into the cylinder in front of the
piston, as was done in his earlier invention. Accordingly, he
located the steam passages behind the piston, and adopted a tightly
fitting piston, and, in order that the piston might remain tight,
he adopted a detached piston rod to relieve the piston from lateral
strain. The specification states that"
"the piston is disconnected from its rod to prevent any lateral
strain being communicated to it, thereby decreasing, to some
extent, the wear of the piston in the cylinder;"
"and, further:"
" if the piston is closely fitted, it will wear a long time with
very little leakage, and what there may be will be caught in the
annular grooves in the side of the piston and passed at once
through the exhaust passages, thus preventing any leakage through
the piston rod."
"The drawings show a detached piston rod, and all the
cooperative devices are conformed and adjusted to a detached rod,
such as the long sleeve in the cylinder, to guide it, and the
collar on the end of the rod to limit its movements."
"It is impossible to ignore the particular construction of these
two parts which is thus pointed out as material. As the defendant's
bell ringer does not contain such a piston or piston rod,
infringement is not shown. The bill is therefore dismissed."
18 F. 602.
On this appeal it is argued, on behalf of the appellants, that
this construction of their patent is too narrow, and it is now
contended that the detachment of the piston and piston rod is not
an essential part of the description and claim of the invention
patented. We cannot, however, but agree with the circuit judge that
the language of the specification limits the first claim to a
combination in which the piston and piston rod are detached from
each other. In describing his invention in the introductory part of
the specification, the patentee manifestly divides it into two
parts. The first relates
"to the construction
Page 121 U. S. 630
of a steam bell ringer in such a manner as to prevent any
apparent leakage, either of water or steam, without resorting to
the use of stuffing boxes;"
the second,
"to cause the admission and release of the steam directly by the
motion of the piston, and without the use of any intermediate parts
between the piston and valves."
The first claim covers the first part of this invention by "the
combination of the cylinder A, piston G, piston rod D, slotted rod
C, and crank B, when constructed and operated substantially as
described." The second claim, which we need not further consider
here, because not involved in the case, covers the second part of
the invention.
In the description of the device, with reference to the
drawings, the specification says:
"The piston G is disconnected from its rod D to prevent any
lateral strain's being communicated to it, thereby decreasing, to
some extent, the wear of the piston in the cylinder."
It is not admissible to adopt the argument made on behalf of the
appellants, that this language is to be taken as a mere
recommendation by the patentee of the manner in which he prefers to
arrange these parts of his machine. There is nothing in the context
to indicate that the patentee contemplated any alternative for the
arrangement of the piston and piston rod. The arrangement of the
valves, as shown in the drawings, he declared not to be essential,
and explained how they might be otherwise adjusted, and the
comparative advantage and disadvantage of those plans; but no such
language is used in reference to the connection between the piston
and its rod. And when we compare the device as described in the
specifications of the patent sued on with that of the patent of
1854, in which it was necessary to use stuffing boxes, and consider
that one of the express objects expected to be accomplished by the
improvement contained in the patent of 1872 was to prevent leakage
of water or steam without resort to stuffing boxes, the conclusion
seems unavoidable that the patentee intended the detachment of the
piston from its rod as an essential part of the combination to be
covered by the first claim.
The decree of the circuit court is therefore
Affirmed.