Northern Trailer Co. v. La Plant
| Decision Date | 16 September 1927 |
| Docket Number | No. 7722.,7722. |
| Citation | 21 F.2d 686 |
| Parties | NORTHERN TRAILER CO. et al. v. LA PLANT et al. |
| Court | U.S. Court of Appeals — Eighth Circuit |
George E. Middleton and W. B. Morton, both of New York City (Pennie, Davis, Marvin & Edmonds, of New York City, and Ralph Orwig, of Des Moines, Iowa, on the brief), for appellants.
John B. Macauley, of Chicago, Ill. (John M. Grimm, of Cedar Rapids, Iowa, on the brief), for appellees.
Before KENYON, Circuit Judge, and MOLYNEAUX and JOHN B. SANBORN, District Judges.
The lower court held that appellants' device does not embody patentable invention, and that, upon the assumption of the validity of the claims of said patent, the evidence does not show the same to have been infringed by the appellees' structure.
In our view, as in that of the learned trial judge, appellants' patent No. 1,550,573, when considered in the light of the prior art, does not embody patentable invention.
Appellants' snowplow, of which Mr. Sargent was the inventor, and also appellees' snowplow, were developed shortly after the World War, independently of each other, and in widely separated parts of the United States, at a time when the caterpillar tractor had recently been brought into prominence and general notice by the World War.
The advent of the caterpillar tractor undoubtedly furnished the inspiration to the originators of both the devices in controversy here. Its usefulness and applicability as a heavy duty motor power had attracted wide attention by reason of its employment by the armies engaged in the World War.
The Sargent patent claims, infringement of which is charged, are claims 4, 5, 6, 7, and 10. Claims 4, 6, and 10 are typical:
Each and all of the elements of Sargent's device are concededly old. Appellants' contention is that it comprises a new combination of old elements, resulting in a new and useful result. Appellants' device is composed of a nose, the plow proper, secured to a rearwardly extending frame designed to receive a tractor, which surrounds the tractor when the latter is in position; the tractor being hitched to the rearward bar of the frame by a flexible draft connection between the drawbar and the tractor. Chafing blocks at the front end of the frame are provided to make contact with the tractor at turns. The frame is supported by a sled. This arrangement, of course, results in the plow moving independently and out of sympathy with the tractor and on its own bottom, and thus does not follow every movement of the tractor. The tractor thus following the plow moves on a smoother path than it otherwise would, the snow having been removed by the nose of the plow. This fact, together with the flexible connection, to a large extent obviates the strain on the structure which would be imposed if the plow were rigidly connected with the tractor. The plow structure thus framed around the tractor is guided by it. The plow must perforce turn with the tractor. The tractor is turned by stopping the traction belt on the side towards which the turn is to be made.
In appellants' structure, chafing blocks are placed on the sides of the tractor at the forward end and corresponding blocks are placed on the frame, and the frame is rigidly constructed, so that, when the tractor turns, the chafing blocks upon the tractor come in contact with those upon the frame, thus enabling the tractor to turn the structure without damaging it.
The sled or main supporting runners on which the plow proceeds are connected at their front ends by the forward frame. The sides of the plow are connected to the runners by a link at the rear of the runners and back of the runners. The sides are provided with a short runner section; the construction being such that the frame may be raised or lowered at its forward end to adjust the clearance of the nose of the plow above the ground. The nose of the plow proper is attached to the main side members of the frame by suitable plates and angles, so as to be raised or lowered with the side plates. For raising and lowering the side plates, levers are provided which are fulcrumed on the uprights of the forward frame and pivoted at their front ends to the side frames so that, when the levers are pressed down at their rear ends, the forward ends of the side frame and the nose of the plow will be lifted with respect to the runners. The rear ends of the levers project between the parallel uprights of the rear frame and are held in the designated position by cross pins adapted to be inserted in the series of holes provided in the uprights for that purpose. The plow is provided with side wings to push back the snow from the sides of the plow to widen the cut. The claims in suit are not concerned with the wing construction, which was the subject of appellees' counterclaim.
The two main side frames are connected at their rear ends by an adjustable crossbar, which is held in position by a movable pin so that either end of the crossbar may be swung back to permit the tractor to be driven into its place between the side frames. After the tractor is in place, the crossbar is fastened in place, and the tractor is hitched to it by a flexible connection. At its forward end the side channels of the tractor are provided with horizontally extending chafing blocks, whose metal faces extend laterally beyond the edge of traction belt in a position to engage the vertical chafing blocks or rub irons fastened to the face of the uprights of the forward frame, whereon the thrust of the tractor to right or left will be received and the plow will be steered to the right or left as may be desired; the tractor being loosely inclosed in the frame, there being an inch or so between the frame and the tractor, and connected to the rear drawbar by a flexible connection, the plow as before stated, does not move up and down or act in sympathy with every movement of the tractor. The nose of the plow...
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