1. Reissued letters patent No. 3727, granted by the United
States, Nov. 9, 1869, to Edward H. Ashcroft, assignee of William
Naylor, for an improvement in steam safety valves, being a reissue
of original letters No. 58,962, granted to Naylor Oct. 16, 1866,
cannot, in view of the disclaimer of said Naylor in his
specification, upon which English letters patent No. 1830 were
sealed to him Jan. 19, 1864, and of the prior state of the art, be
construed to embrace a combination, in every form of spring safety
valve, of a projecting, overhanging, downward curved lip or
periphery, with an annular recess or chamber surrounding the valve
seat, into which a portion of the steam is deflected as it issues
between the valve and its seat, but must be limited to a
combination of the other elements of his device, with such an
annular recess of the precise form, and operating in the manner
described, so far as such recess, separately or in combination,
differs in construction or mode of operation from those which
preceded it.
2. Said reissued letters, thus limited, are not infringed by the
use of a steam safety valve made in substantial compliance with the
specification of letters patent No. 58,294, granted Sept. 25, 1866,
to George W. Richardson.
English letters patent No. 1830, dated July 21, 1863, and sealed
Jan. 19, 1864, were granted to William Naylor, of England, for
improvements in safety valves and in apparatus connected therewith.
The specification describes his invention as consisting,
"when using a spring for resisting the valve from opening, in
the employment of a lever of the first order, one end resting by a
suitable pin upon the safety valve, and the other end of the lever
resting upon the spring, the end resting upon the spring being bent
downwards to an angle of about forty five degrees from the fulcrum,
so that when the valve is raised by the steam the other end of the
lever is depressed upon the spring downwards, and at the same time
is moved inwards towards the fulcrum, thus virtually shortening the
end of the lever, and thereby counteracting the additional load
upon the valve as it is raised from its seat by the greater amount
of compression put upon the spring."
He also describes a contrivance consisting of a lateral branch
or escape passage for a portion of the steam after it has passed
the valve, the valve being made to project over the edges of the
exit passage, the projecting edges of the valve being made to
curve
Page 97 U. S. 190
slightly downwards, so that the steam on issuing between the
valve and its seat will impinge against the curved projecting
portion of the valve, and a portion of it be directed downwards
into the annular chamber surrounding the central passage, which
chamber communicates at once with the branch exit pipe, whilst the
other portion of the steam ascends past the edges of the valve. He
then says,
"By this means I am enabled to avail myself of the recoil action
of the steam against the valve, for the purpose of facilitating the
further lifting of such valve when once opened; but I wish it to be
understood that I lay no claim to such recoil action, nor to the
extension of the valve laterally beyond its seat."
The specification of English letters patent No. 1038, granted to
Charles Beyer for improvements in safety valves, dated April 25,
1863, and sealed Oct. 16, 1863, describes his invention as
consisting
"in forming a flange around the valve, commencing at the outer
edge of the valve facing, which flange is under cut and concave in
shape, and the concave side is towards the seating of the valve,
which has also a flange upon it, commencing at the outer edge of
the valve seating, but the upper surface of this flange is convex,
and corresponds nearly to the concave surface of the flange upon
the valve. There is a slight space between the concave and convex
surfaces of the two flanges, which diminishes towards the outer
edges of the flanges. When the steam begins to escape from between
the surfaces of the valve, it gets between the concave and convex
surfaces of the two flanges, and its force thus acts upon a larger
area, and reacts upon the concave surface of the valve, and causes
it to open to a greater extent than the ordinary valve."
Letters patent of the United States No. 58,962 were issued, Oct.
16, 1866, to said Naylor for an improvement in safety valves. The
description of his invention in the specification is substantially
the same as in that of his English patent. Nothing is said,
however, of availing himself of the "recoil action of the steam
against the valve, for the purpose of facilitating the further
lifting of such valve when once opened;" nor is there any
disclaimer, as in the English specification, of the recoil action
and the extension of the valve laterally beyond its seat. The claim
of the specification was the arrangement
Page 97 U. S. 191
in safety valves "of bent levers of the first order, acting in
combination with a spring or springs, the whole operating in the
manner and for the purpose set forth." Sept. 8, 1869, Naylor
assigned his letters patent to Edward H. Ashcroft, who thereupon
surrendered them for reissue. The specification of the reissued
letters to Ashcroft, as the assignee of Naylor, which are No.
3,727, and bear date Nov. 9, 1869, declares that the main object to
be attained by the invention,
viz., the counteracting the
additional load upon the valve as it is raised from its seat
produced by the increased resistance of the spring,
"is accomplished by using a lever of the first order, one end
resting by a suitable pin upon the safety valve, constructed and
arranged as hereinafter described, and the other end of the lever
resting upon a spring; but, in lieu of having this lever straight
or nearly so, I propose to bend downward that end which is acted
upon by the spring to an angle of about forty five degrees, so that
when the valve is raised by the steam the other end of the lever is
depressed upon or against the spring downward, and at the same time
is moved inward toward the fulcrum, thus virtually shortening the
end of the lever, and thereby counteracting the additional load
upon the valve as it is raised from its seat by the greater amount
of compression or tension, as the case may be, which is put upon
the spring; and my invention also consists in the valve C,
constructed with projecting downward curved lip or periphery, and
in the annular chamber D, surrounding the valve seat, whereby, as
the spring is compressed by the lifting of the valve, the
projecting lip of the valve and the annular recess are available in
causing an increased pressure on the valve, and thus overcome the
increased resistance of the spring, due to its compression, as
hereinafter more fully set forth."
"Figs. 1 and 2 represent, respectively, a vertical section and
front elevation of a safety valve constructed according to my
invention."
"A is the main thoroughfare, leading directly from the boiler;
B, a lateral branch or escape passage for a portion of the steam
after it has passed the valve C. I make this valve to project over
the edges of the exit passage A, and to curve its projecting edges
slightly downward, as shown in Fig. 1, so
Page 97 U. S. 192
that the steam, on issuing between the valve and its seat, will
impinge against the curved projecting portion of the valve, and a
portion of it will be directed downward into the annular chamber D,
surrounding the central passage A, and communicating with the exit
pipe B, while the other portion of the steam ascends past the edge
of the valve."
The claims of the reissue are:
"1. The combination and arrangement, with the hereinbefore
described safety valve, of bent levers of the first order, and the
spring or springs, in the manner substantially as hereinbefore set
forth."
"2. The safety valve C, with its overhanging, downward curved
lip or periphery, and annular recess D, substantially as herein
shown and described, and for the purpose set forth."
"3. The annular recess D, surrounding the valve seat,
substantially as herein set forth."
"4. The combination of the valve C and the annular recess D, as
herein set forth, and for the purpose described."
Figs. 1 and 2 are as follows:
image:a
Page 97 U. S. 193
Dec. 14, 1869, this bill was filed by Ashcroft, to enjoin the
alleged infringement by the Boston and Lowell Railroad Company of
his reissued letters. The answer denied that they were for the same
invention as that described in the original letters, that Naylor
was the first and original inventor of the improvements specified
in the reissued letters, or that they embrace the valve used by the
company, and averred that the valves used by it were described by
and embraced in letters patent of a prior date to that of Naylor's
invention, and were made under letters patent No. 58,294, granted
by the United States, Sept. 25, 1866, to George W. Richardson.
The specification of Richardson's patent describes his invention
as follows:
"E E is the valve seat."
"F F is the ground joint of the valve and seat."
"P is the countersink or centre upon which the point of the stud
extending from the scale lever rests in the usual manner."
"The nature of my invention consists in increasing the area of
the head of the common safety valve outside of its ground joint,
and terminating it in such a way as to form an increased resisting
surface, against which the steam escaping from the generator shall
act with additional force after lifting the valve from its seat at
the ground joint; and so, by overcoming the rapidly increasing
resistance of the spring or scales, insure the lifting of the valve
still higher, thus affording so certain and free a passage for the
steam to escape as effectually to prevent the bursting of the
boiler or generator, even when the steam is shut off and damper
left open."
"To enable others skilled in the art to make and use my
invention, I will proceed to describe its construction and
operation. To the head of the common safety valve, indicated by all
that portion of Fig. 2 lying within the second circle from the
common centre, I add what is indicated by all that portion lying
outside of the said circle, in about the proportion shown in the
figure. A transverse vertical section of this added portion is
indicated, in Fig. 4, by those portions of the figure lying outside
of the dotted lines
p p, p p, while all that portion lying
within the dotted lines
p p, p p indicates a transverse
vertical section of the common safety valve alone. This increased
area may be made by adding to a safety valve already in use, or by
casting the whole entire. "
Page 97 U. S. 194
"I terminate this addition to the head of the valve with a
circular or annular flange or lip
c c, which projects
beyond the valve seat E E, Fig. 3, and extends slightly below its
outer edge, fitting loosely around it and forming the circular or
annular chamber D D, whose transverse section, shown in the figure,
may be of any desirable form or size. This flange or lip
c
c, fitting loosely around the valve seat E E, is separated
from it by about 1/64th of an inch for an ordinary spring or
balance. For a strong spring or balance this space should be
diminished, and for a weak spring or balance it should be increased
to regulate the escape of the steam as required. Instead of having
the flange or lip
c c project beyond, and extend below and
around the outer edge of the valve seat, as shown in Fig. 3, a
similar result may be attained by having the valve seat itself
project beyond the outer edge of the valve head and terminating it
with a circular or annular flange or lip, extending slightly above
and fitting loosely around the outer edge of the flange or lip
c c of the valve head, but I consider the construction
shown in Fig. 3 preferable."
"With my improved safety valve, constructed as now described,
and attached to the generator in the usual way, the steam escaping
in the direction indicated by the arrows in Fig. 3 first lifts the
valve from its seat at the ground joint E F, and then, passing into
the annular chamber D D, acts against the increased surface of the
valve head, and by this means, together with its reaction produced
by being thrown downwards upon the valve seat F E, it overcomes the
rapidly increasing resistance of the spring or balance, lifts the
valve still higher, and escapes freely into the open air until the
pressure in the generator is reduced to the degree desired, when
the valve will be immediately closed by the tension of the spring
or balance. The escape of the steam, by means of this safety valve,
is so certain and free, that the pressure of the steam in the
generator or boiler will not increase beyond the point or degree at
which the valve is set to blow off."
"What I claim as my improvement, and desire to secure by letters
patent, is a safety valve with the circular or annular flange or
lip
c c constructed in the manner, or substantially in the
manner, shown, so as to operate as and for the purpose herein
described."
The drawings referred to in Richardson's specification are as
follows:
Page 97 U. S. 195
image:b
The court below, upon final hearing, dismissed the bill, upon
the ground that there was no infringement. The complainant then
appealed here.
MR. JUSTICE CLIFFORD delivered the opinion of the Court.
Causes of action arising under the patent laws are originally
cognizable, as well in equity as at law, by the circuit courts, or
the district courts having the power and jurisdiction of a circuit
court, subject to the condition that the final judgment or decree
in such a case may be removed here for reexamination.
Page 97 U. S. 196
Improvements were made by William Naylor in steam safety valves,
for which, on the 16th of October, 1866, he obtained letters patent
of the United States; and it appears that he subsequently assigned
the patent to the complainant, and that the complainant, as such
assignee, surrendered and obtained the reissued patent which is the
foundation of the present suit. Wrongful infringement is charged,
and the complainant prays for an account and for an injunction.
Service was made; and the respondents appeared and set up certain
defenses in their answer, as follows:
1. That the reissued patent is not for the same invention as the
original.
2. That the assignor of the complainant was not the original and
first inventor of the improvement.
3. That the reissued patent does not cover and embrace the
safety valve used by the respondents.
4. That safety valves such as are used by the respondents were
described and patented in letters patent granted prior to the
patent and supposed invention of the assignor of the complainant,
as alleged in the answer.
Proofs were taken, the parties heard, and the circuit court
entered a final decree dismissing the bill of complaint.
Due appeal was taken by the complainant, and he assigns the
following errors:
1. That the court erred in giving weight to the disclaimer of
the supposed inventor, as set forth in his English patent.
2. That the court erred in ruling that the patent of the
complainant must be limited to claims for a combination of the
valve described in the specification, with the annular recess
surrounding the central chamber, as explained in the court's
opinion.
3. That the court erred in deciding that the assignor of the
complainant did not invent the overhanging, downward curved lip,
and that he was not the first to use an annular chamber surrounding
the valve seat, into which a portion of the steam is deflected as
it issues between the valve and the seat.
4. That the court erred in deciding that the valve used by the
respondents is not within the complainant's reissued patent.
5. That the court erred in deciding that there is a substantial
difference between the valve used by the respondents and the valve
described in the complainant's reissued patent.
Preliminary to the investigation of the inquiries suggested
in
Page 97 U. S. 197
the errors assigned by the appellant, it becomes expedient to
ascertain what is the construction of the patent described in the
bill of complaint, and whether the same has been infringed by the
respondents. Obvious convenience suggests that these two matters be
first determined, for the plain reason that, if the proofs fail to
establish the charge of infringement, most or all of the errors
assigned will become immaterial in disposing of the case.
Persons seeking redress for the unlawful use of letters patent
are obliged to allege and prove that they, or those under whom they
claim, are the original and first inventors of the improvement
described in the patent, and that the same has been infringed by
the party against whom the suit is brought. Both of those
allegations must be proved by the party instituting the suit; but
where he introduces the patent in evidence, it affords a
prima
facie presumption that the first allegation is true, and
inasmuch as it is not controverted in the answer in this case, the
finding in that regard must be in favor of the complainant.
Suppose that is so, still the charge of infringement is denied
by the respondents, which issue cannot be satisfactorily determined
without first ascertaining the true nature and character of the
improvement secured to the complainant in his reissued letters
patent.
Three patents -- one in England, two in the United States --
were granted to the complainant or his assignor for the improvement
which is the subject of the present controversy. Naylor, it is
claimed, was the inventor of the patented improvement, and he took
out his first patent in England, where he resided. As the patentee
states, the invention relates to certain improvements in safety
valves, and consists, when using a spring for resisting the valve
from opening, in the employment of a lever of the first order, one
end resting by a suitable pin upon the safety valve, and the other
end of the lever resting upon the spring, the end resting upon the
spring being bent downwards to an angle of about forty five degrees
from the fulcrum, so that when the valve is raised by the steam the
other end of the lever is depressed upon the spring downwards, and
at the same time is moved inwards towards the fulcrum, thus
Page 97 U. S. 198
virtually shortening that end of the lever, and thereby
counteracting the additional load upon the valve as it is raised
from its seat by the greater amount of compression put upon the
spring.
Exceptional modifications in certain features of the improvement
are subsequently suggested, and then the patentee proceeds to
explain the functions of the different devices by reference to the
drawings, in the course of which he states that he prefers to make
the valve project over the edges of the exit passage and to curve
the projecting edges of the valve slightly downwards, so that the
steam on issuing between the valve and its seat will impinge
against the curved projecting part of the valve, which will direct
a portion of it downwards into the annular chamber surrounding the
central passage, while the other portion of the steam ascends past
the edges of the valves. By that means the patentee states that he
is enabled to avail himself of the recoil action of the steam
against the valve, for the purpose of facilitating the further
lifting of the valve when once opened; but he adds, what it is
important to notice, that he wishes it to be understood that he
lays no claim to such recoil action, nor to the extension of the
valve laterally beyond its seat.
Prior to that, a safety valve of substantially the same mode of
operation had been patented in the same country to Samuel Beyer,
and the reasonable presumption is that the disclaimer was inserted
in the patent subsequently granted, because it had been previously
invented by another.
Letters patent to Charles Beyer were sealed Oct. 16, 1863, and
the patentee states that his invention consists in forming a flange
round the valve, commencing at the outer edge of the valve facing,
which flange is under cut and concave in shape, and that the
concave side is towards the seating of the valve, which has also a
flange upon it, commencing at the outer edge of the valve seating,
but that the upper surface of the flange is convex, and corresponds
nearly to the concave surface of the flange upon the valve. There
is a slight space between the concave and convex surfaces of the
two flanges, which diminishes towards the outer edge of the same.
When the steam begins to escape from between the surfaces of the
valve, it gets
Page 97 U. S. 199
between the concave and convex surfaces of the two flanges, and
thus acts upon a larger area, and reacts upon the concave surface
of the valve, and causes it to open to a greater extent than the
ordinary safety valve. Such a valve, the patentee states, will lift
promptly when the required pressure is obtained, and will open to a
much greater extent than the valve in common use prior to that
invention. Extra pressure upon the valve will readily close it
after it has lifted, but it does not shut self acting till the
pressure in the boiler has diminished several pounds below the
pressure at which the valve was lifted.
Without more, these suggestions are sufficient to show that the
Beyer patent, which antedates the invention of the complainant,
contains substantially the same mode of operation to produce the
recoil action of the steam as that disclaimed in the English
patent, and shows that the disclaimer was in all probability made
because it was well known to the patentee and to the officials who
issued the letters patent that another was the original and first
inventor of the patented valve. Nothing of the kind is embraced in
the claims of the English patent granted to the patentee, nor is
there any thing in the specification which has any tendency to show
that the patentee ever supposed that he invented that feature of
the improved valve which he disclaimed.
Two patents for the improvement have been granted in this
country -- one, the original, to the alleged inventor, and the
reissued patent to the complainant, on which the suit is founded.
Neither of them contains any disclaimer of the kind mentioned in
the English patent, though it is conceded that both the original
and the reissued patent were granted for the same invention as the
English patent. Nor could that concession properly be withheld, as
it is as certain as truth that the feature of the steam valve in
question was fully and clearly described in that specification, and
that the patentee stated that he wished it to be understood that he
did not lay any claim to the recoil action, nor to the extension of
the valve laterally beyond its seat.
Explicit as that disclaimer is, still it is assigned for error
by the complainant that the circuit judge erred in giving
weight
Page 97 U. S. 200
to it; but the Court here is of the opinion that there is no
merit in that objection. Instead of that, the Court decides that
the patent in suit, in order that it may be held valid, must be
construed in view of the disclaimer contained in that patent, and
be limited to the particular devices shown in the specification for
effecting such recoil action of the steam.
Taken as a whole, the facts show conclusively that the assignor
of the complainant was not the first person to devise means for
using the recoil action of steam to assist in lifting the seat of
the steam valve for the purpose described, and it follows that the
patent in suit must be limited to what he actually invented, which
is the devices, shown in the specification and drawings, to enable
the party to avail himself of such recoil action.
Decided support to that view is found in the specification of
the Beyer patent, which shows that the apparatus in question had an
overhanging, downward curved lip, and an annular recess into which
the steam was directed downwards on issuing between the valve and
its seat, while a portion of the steam impinged against the
projecting part of the valve.
Viewed in the light of that suggestion, it is clear, as decided
by the circuit judge, that the assignee of the invention in
controversy cannot claim that Naylor was the original and first
inventor of that feature of the improvement, nor can it properly be
claimed that he invented the combination in a spring safety valve
of every form of a projecting, overhanging, downward curved lip in
such a device, with the annular recess surrounding the valve seat,
into which a portion of the steam is deflected as it issues between
the valve and its seat. Limited in that way as the patent must be,
in order that it may be upheld as valid, the question remains
whether it has been infringed by the respondents.
Throughout, the steam valve used by the respondents is the valve
patented to George W. Richardson, whose patent makes a part of the
record. He obtained his patent Sept. 25, 1866, nearly a month
earlier than the date of the original American patent granted to
Naylor. His invention, as he describes it, consists in increasing
the area of the head of the common
Page 97 U. S. 201
safety valve outside of its ground joint, and terminating it in
such a way as to form an increased resisting surface, against which
the steam escaping from the generator shall act with additional
force after lifting the valve from its seat at the ground joint,
and so by overcoming the rapidly increasing resistance of the
spring or scales will insure the lifting of the valve still higher,
thus affording so certain and free a passage for the steam to
escape as effectually to prevent the bursting of the boiler or
generator, even when the steam is shut off and the damper left
open.
Safety valves previously in use were not suited to accomplish
what was desired, which was to open for the purpose of relieving
the boiler, and then to close again at a pressure as nearly as
possible equal to that at which the valve opened. Sufficient
appears to show that Richardson so far accomplished that purpose as
to invent a valve which would open at the given pressure to which
it was adjusted and relieve the boiler, and then close again when
the pressure was reduced about two and one half pounds to the inch,
even when the pressure in the generator was one hundred pounds to
the same extent of surface, which made it in practice a useful
spring safety valve, as proved by the fact that it went almost
immediately into general use.
Other inventors prior in date to the Naylor invention attempted
to make the desired improvement in the common safety valve, and it
is evident from what appears in the record that the efforts of one
or more of them besides Beyer were attended with more or less
success; but it is unnecessary to enter into those details, as it
is obvious from what appears in the Beyer patent that Naylor did
not invent the overhanging, downward curved lip of the improved
valve, nor was he the first to use an annular chamber surrounding
the valve seat, into which a portion of the steam is deflected as
it issues between the valve and its seat; and the Court here
concurs with the circuit judge that his patent must be limited to
the combination of the other elements with such an annular recess
as he has described, and operating in the described manner, so far
as such recess separately considered or in combination differs in
construction and mode of operation from the patented steam
valves
Page 97 U. S. 202
which preceded it, as shown in the evidence giving the
antecedent state of the art. It follows, therefore, that the claims
of the reissued patent in suit cannot be held to cover the safety
valve used by the respondents, which in its construction and mode
of operation is substantially different, as appears from a
comparison of the models and an inspection of the drawings, as well
as from the description given of the same in the respective
specifications.
Support to that view of a decisive character is also derived
from the testimony of the expert witnesses on both sides. Enough
appears in the explanations of the specification and the expert
testimony to satisfy the Court that it was the intention of the
inventor of the complainant's valve to use the impact of the
issuing steam upon the concave lip of the valve to assist in
lifting it without other aid, except so far as it was helped by the
diminution of atmospheric pressure on the top of the valve,
consequent upon the issuing of a portion of the steam in an upward
direction around the periphery of the valve, the annular chamber
into which the steam is discharged on leaving the valve serving no
other purpose than that of a conduit for the steam, if the valve is
constructed in accordance with the drawings of the original
patent.
Examined in the light of these suggestions, it is plain that the
steam valve used by the respondents cannot be held to be an
infringement of that described in the specification of either of
the three patents representing the invention claimed by the
complainant.
Coming to the specification that describes the steam valve used
by the respondents, it will at once be seen that its construction
and mode of operation is substantially different in important
particulars, as follows: when the valve opens, the steam expands
and flows into the annular space around the ground joint. Its free
escape, which might otherwise be too free, is prevented by a
stricture or narrow space formed by the outer edge of the lip and
the valve seat. By these means, the steam escaping from the valve
is made to act by its expansive force upon an additional area
outside of the device, as ordinarily constructed, to assist in
raising the valve, the stricture being enlarged as the valve is
lifted from its seat, and varying
Page 97 U. S. 203
in size as the quantity of the issuing steam increases or
diminishes.
Important functions, not very dissimilar in the effect produced,
are performed by the two patented valves in controversy, but the
means shown in the respective specifications, and the mode of
operation described to produce the effect, are substantially
different in material respects, which shows to a demonstration that
the complainant cannot prevail unless it can be held that his
assignor invented the overhanging, downward curved lip, and that he
was the first to use an annular chamber surrounding the valve seat,
into which a portion of the steam is deflected as it issues between
the valve and its seat. Neither of those conditions can be found in
favor of the complainant, and of course it cannot be held that the
respondents have infringed his patent.
Confirmation of that conclusion of the most decisive character
is found in the testimony of the experts, which will not be
reproduced, as it would extend the opinion beyond a reasonable
length.
Experiments almost without number were made by the experts, and
the court is furnished with very many exhibits intended to explain
the construction and mode of operation of the different steam
valves described in the various patents given in evidence in the
case; but the Court has not found it necessary to enter into those
details, preferring to rest the decision upon the construction of
the complainant's patent and his failure to show that it has been
infringed by the respondents.
Decree affirmed.
