1. Patent No. 1,379,224 (Claims 1 and 2), granted to Owen P.
Smith, for improvements in devices for dog races, which calls for a
lure-carrying arm, attached or hinged to a conveyor car, and
equipped with a wheel at its outer end for ground support, is
narrowly limited, and does not cover a rigid horizontal
lure-carrying arm without ground support. P. 282 U. S.
2. Where an applicant for a patent to cover a new combination is
compelled by the rejection of his application by the Patent Office
to narrow his claim by the introduction of a new element, he
cannot, after the issue of the patent, broaden his claim by
dropping that element. P. 282 U. S.
3. Where a patentee has narrowed his claim in order to escape
rejection, he may not, by resort to the doctrine of equivalents,
give to the claim the larger scope which it might have had without
the amendments which amount to disclaimer. P. 282 U. S.
4. Patent No. 1,507,440, to Owen P. Smith, which relates to the
form and supports of a casing used to house the tracks upon which
runs the car conveying the lure-carrying arm in dog races, is
void for want of novelty and invention. P.
282 U. S.
38 F.2d 170 affirmed.
Certiorari, 281 U.S. 714, to review a decision which reversed a
decree of the district court upholding the petitioner's patent in
an infringement suit.
Page 282 U. S. 785
MR. CHIEF JUSTICE HUGHES delivered the opinion of the Court.
This suit was brought in the District Court of the United States
for the Northern District of Oklahoma to enjoin the infringement of
letters patent No. 1,379,224, May 24, 1921, and No. 1,507,440,
September 2, 1924 (and also three other patents not here involved),
issued to Owen P. Smith, the petitioner's intestate, for
improvements in devices for dog races. A special master was
appointed to hear and determine the issues. The master reported
that each of the patents was valid and infringed. The district
court approved the report and entered a decree for injunction, and
for recovery, upon a bond given under the order of the Court, of
damages. This decree was reversed by the Circuit Court of Appeals
for the Tenth Circuit. 38 F.2d 170. This decision was in conflict
with that the Circuit Court of Appeals for the Fifth Circuit in
American Electric Rabbit Racing Assn. v. Smith,
1016, affirming, without discussion, the decree of the District
Court for the Eastern District of Louisiana, 21 F.2d 366, which
held patents No. 1,379,224 and No. 1,507,440 to be valid and
infringed. In view of this conflict, this Court granted a writ of
certiorari in the instant case. 281 U. § 714
These patents were also before the District Court for the
Southern District of Ohio in Smith v. Springdale Amusement
where the bill of complaint was dismissed for want of
infringement, 39 F.2d 92, and the decree was affirmed by the
Circuit Court of Appeals for the Sixth Circuit, 40 F.2d, 173;
certiorari granted, post,
Patent No. 1,379,224.
The claims in suit are numbers 1
and 2, as follows:
Page 282 U. S. 786
"1. In a dog racing amusement, a race course suited for dogs, a
casing extending around the outer side of the racecourse and
provided with a longitudinal opening, a mechanical conveyer
including a track extending around the race course and located
within the casing, and a conveyer car mechanically operated upon
said track and provided with an arm extending through the
longitudinal opening of the casing in a projecting position over
the track and adapted to carry a lure, and a wheel rotatably
mounted on and supporting the arm at the projecting end
"2. In an amusement, the combination of a racecourse suited for
dogs, a covered rail track adjacent said course on one side, a
conveyor car mechanically operated upon said track, a horizontally
extending arm hinged to said car extending midway of said course, a
wheel rotatably mounted near the end of said arm, and resting upon
the ground, a platform supported by said arm and a lure or quarry
mounted upon said platform for attracting the dogs."
The prior art shows various contrivances for carrying an
artificial lure around a track in front of racing dogs. Hind, 1884
(British, No. 4274), described an inanimate lure moved by means of
a rope traveling along a sunken trough. Pinard, 1887 (No. 362,396),
proposed a lure carrier dragged upon the ground by a cable winding
upon a drum at the end of the track. Moss, 1896 (British, No.
9058), showed a device, on the order of an electric trolley system,
with a rail laid on the race course. Walsh, 1898 (No. 611,876),
placed his conveyor car adjacent to the track and separated from it
by a fence, and provided an arm reaching over the fence and
connected with another arm, pliant or stiff, which extended
downward to the lure-carrying mat dragging on the ground. Smith
1912 (No. 1,038,504), provided an underground track, within and
beneath the race course, and a conveying mechanism hidden from view
and carrying the lure which
Page 282 U. S. 787
was visible above the ground. Everett, 1913 (No. 1,052,807),
followed Smith, using an underground cable.
Smith, in the combination for which the patent in suit (No.
1,379,224) was issued, placed his covered rail track adjacent to
the racecourse, and the connected the cooperating elements of
conveyor car and lure by an arm horizontally extending over the
course. The distinctive feature of his invention is set forth in
Claim 1 as
"an arm extending through the longitudinal opening of the case
in a projecting position over the track and adapted to carry a
lure, and a wheel rotatably mounted on and supporting the arm at
the projecting end thereof;"
and, in Claim 2, as
"a horizontally extending arm hinged to said car extending
midway of said course, a wheel rotatably mounted near the end of
said arm, and resting upon the ground, a platform supported by said
arm and a lure or quarry mounted upon said platform for attracting
The petitioner asserts that, by his apparatus, Smith surmounted
the difficulties encountered in the impracticable devices of the
prior art and led to commercial success. The circuit court of
appeals in the instant case, while finding that there was no
infringement, had no doubt that Smith's device was an improvement
over the prior art, and assumed that it was patentable. 38 F.2d at
171. We make the same assumption. Smith's improvement, however, was
in a limited field. There was manifestly no invention in a
combination consisting of a rail track, with a casing adjacent to
the course, a conveyor car, and an arm projecting over the course
and connected with a mechanical lure carried in advance of racing
dogs. Patentability could be predicated of Smith's improvement only
by reason of the distinctive feature of the arm which he
The differences in the respondents' apparatus which are urged as
avoiding infringement are that the respondents
Page 282 U. S. 788
use a rigid horizontal arm, that it is not hinged to the car,
that there is no wheel, and that the arm has no ground support at
its free end; and, further, that the respondents has located their
conveyor housing on the inner side of the race course, while Claim
1 of the patent puts the casing on the outer side. We may at once
dispose of the latter point, as we find no basis for the conclusion
that the invention of the patent is limited to a location of the
casing on the outer side of the course. There is no such limitation
in Claim 2. The important question is whether the patent covers a
rigid horizontal lure-carrying arm without ground support.
It appears from the file wrapper that in the application which
resulted in patent No. 1,379,224. Smith made, among others, the
"3. In an amusement, the combination of a racetrack suited for
dogs, a covered rail track adjacent said course, a conveyor car
mechanically operated upon said track, an arm attached to said car
extending midway of said course, a wheel rotatably mounted on said
arm, and a lure mounted on said arm."
This claim was rejected on the prior patent to Walsh (No.
611,876). Another claim (then numbered 4) was allowed as originally
presented, and is Claim 2 of the patent. Smith did not contest the
rejection of original Claim 3, above mentioned, but proposed an
amendment which related to the casing. This amendment was rejected
"on either Walsh or Moss," the examiner stating "that Moss is
provided with a housing and it would not be invention to provide
Walsh with one." Without further contest, Smith then cancelled the
rejected Claim 3 and substituted what is now Claim 1 of the patent.
On comparing the claim as thus allowed and the rejected claim, it
appears that the important difference was that, instead of claiming
"an arm attached to said car extending midway of said course, a
Page 282 U. S. 789
mounted on said arm, and a lure mounted on said arm," the claim
was made to read
"an arm extending through the longitudinal opening of the casing
in a projecting position over the track and adapted to carry a
lure, and a wheel rotatably mounted on and supporting the arm at
the projecting end thereof."
The petitioner insists that the gist of Smith's invention was
"the straight-out lure-carrying arm laterally extending and
operating exclusively in a substantially horizontal plane." But it
will be observed that the rejected and abandoned claim was the
broad one of "an arm attached to said car extending midway of said
course," and that the new claim, as proposed and allowed, did not
specify a horizontal arm alone. The essential difference in the
allowed claim lay in the specification of the wheel "as supporting
the arm at the projecting and thereof." Claim 2 (original Claim 4),
which was allowed without question, specified a horizontal arm
hinged to the car and resting on a wheel. A rigid, horizontal arm,
without hinge or wheel, was not the subject of either claim.
The case, in our opinion, thus calls for the application of the
principle that, where an applicant for a patent to cover a new
combination is compelled by the rejection of his application by the
Patent Office to narrow his claim by the introduction of a new
element, he cannot, after the issue of the patent, broaden his
claim by dropping the element which he was compelled to include in
order to secure his patent. Shepard v. Carrigan,
116 U. S. 593
116 U. S. 597
As this Court said in I.T.S. Rubber Co. v. Essex Rubber
Co., 272 U. S. 429
272 U. S.
"If dissatisfied with the rejection, he should pursue his remedy
by appeal, and where, in order to get his patent, he accepts one
with a narrower claim, he is bound by it. Shepard v. Carrigan,
supra, 116 U. S. 597
v. United States, 179 U. S. 77
, 179 U. S.
. Whether the examiner was right or wrong in rejecting
the original claim, the court is not to inquire. Hubbell
Page 282 U. S. 790
United States, supra, 179 U. S.
. The applicant, having limited his claim by amendment
and accepted a patent, brings himself within the rules that, if the
claim to a combination be restricted to specified elements, all
must be regarded as material, and that limitations imposed by the
inventor, especially such as were introduced into an application
after it had been persistently rejected, must be strictly construed
against the inventor and looked upon as disclaimers. Sargent v.
Hall Safe & Lock Co., 114 U. S. 63
, 114 U. S.
; Shepard v. Carrigan, supra, 116 U. S.
; Hubbell v. United States, supra,
179 U. S. 85
. The patentee is
thereafter estopped to claim the benefit of his rejected claim or
such a construction of his amended claim as would be equivalent
thereto. Morgan Envelope Co. v. Albany Paper Co.,
152 U. S.
, 152 U. S. 429
The petitioner resorts to the doctrine of equivalents, insisting
that the rigid horizontal arm of the respondents is to be treated
as the equivalent of the arm of the patent, and that the limiting
specifications of the claims may be ignored. What has already been
said disposes of this contention, for where a patentee has narrowed
his claim in order to escape rejection, he may not,
"by resort to the doctrine of equivalents, give to the claim the
larger scope which it might have had without the amendments, which
amount to disclaimer."
Weber Electric Co. v. Freeman Electric Co.,
256 U. S. 668
256 U. S.
-678; I.T.S. Rubber Co. v. Essex Rubber Co.,
It should also be observed that the difference here was
both in structure and in mode of operation and result. Petitioner's
witness testified that Smith "built cars with rigid arms and had
the arms snap off," and
"that is why he went to the wheel and hinge. It reduces the
friction there, I guess you would call it, crystallizing the arm
from the vibration. If the arm was at the end and no wheel to
support it, it would naturally drag on the track."
Respondents' witness testified that the difference in the arm
they used, which does not include
Page 282 U. S. 791
the wheel for supporting the arm, is that, when the arm "has a
wheel under the end as it runs over the track, it doesn't have any
vibration;" that vibration makes the lure "jump up and down" giving
it a more lifelike appearance.
We agree with the decision of the circuit court of appeals that
infringement of letters patent No. 1,379,224 was not
Patent No. 1,507,440.
This patent is for "Housing for
Conveyor Cars and Tracks." It relates to the casing element called
for by patent No. 1,379,224. The claims as originally presented
were rejected "as indefinite and as aggregations." Other claims
were substituted, which included Claim 1 of the patent, as allowed,
"1. In a housing for covering tracks and cars having laterally
extending arm operated upon said track, the combination of posts
set in the ground at the sides of said track, timbers attached to
said posts to form a frame, and boards attached to said timbers and
posts to form a continuous enclosure above said track, and having a
continuous opening in one side of said housing adapted to permit
extension of the laterally extending arm therethrough, and truss
rods attached to the closed side of the housing adapted to support
the side of said housing above the said continuous opening."
All the elements in this claim were old. So far as the
continuous opening "adapted to permit extension of the laterally
extended arm" is concerned, there was anticipation by Bertram,
1903, No. 729,120, whose housing for a third or electric rail
disclosed a similar method of contact with an outside track, in
providing for a casing (enclosing the electric rail) "in which is
formed a longitudinal slot or opening." A comparison of Claim 1 of
the patent with the other claims which were rejected and cancelled
shows that the distinctive features of the claim allowed were that
the opening was placed "in one side of said
Page 282 U. S. 792
housing," and that there was a specification of a particular
sort of support -- that is, "truss rods attached to the closed side
of the housing." In other claims allowed, the reference is to
"adjustable stay rods."
The Circuit Court of Appeals for the Tenth Circuit, in the
instant case, questioned the patentability of the device and said
that, if patentability existed at all, it must depend upon the
truss rod support or the adjustable stay rods, neither of which the
respondents use. We agree with this statement, and we are also of
the opinion, as was the Circuit Court of Appeals for the Sixth
Circuit (Smith v. Springdale Amusement Park, supra
supplying the feature of the truss rods and the adjustable stay
rods did not constitute invention. To provide such supports would
be but a step obvious to any skilled mechanic. Atlantic Works
v. Brady, 107 U. S. 192
107 U. S. 200
Railroad Supply Co. v. Elyria Iron & Steel Co.,
244 U. S. 285
244 U. S. 292
Powers-Kennedy Contracting Corp. v. Concrete Mixing &
Conveying Co., 282 U. S. 175
282 U. S.