Pennsylvania Co v. Locomotive Engine Safety Truck Co

• Citation: 110 U.S. 490,4 S.Ct. 220,28 L.Ed. 222
• Parties: PENNSYLVANIA R. CO. v. LOCOMOTIVE ENGINE SAFETY TRUCK CO. 1
• Decision Date: 03 March 1884
• Court: United States Supreme Court

110 U.S. 490

4 S.Ct. 220

28 L.Ed. 222

PENNSYLVANIA R. CO. v. LOCOMOTIVE ENGINE SAFETY TRUCK CO.¹

March 3, 1884.

A. McCallum, Geo. Harding, and Francis T. Chambers, for appellant.

Samuel S. Hollingsworth and Edmund Wetmore, for appellee.

GRAY, J.

This is an appeal by the defendant below from a decree against it upon a bill in equity for the infringement of letters patent granted on February 11, 1862, to Alba F. Smith, for an improvement in trucks for locomotive engines, the specification annexed to which, except the drawings and the letters referring to them, and the formal beginning and conclusion, was as follows: 'Several laterally-moving trucks have heretofore been made and applied to railroad cars. My invention does not relate broadly to such laterally-moving trucks; but my said invention consists in the employment, in a locomotive engine, of a truck or pilot wheels provided with pendant links, to allow of a lateral movement, so that the driving wheels of the locomotive engine continue to move correctly on a curved track in consequence of a lateral movement allowed by said pendant links, the forward part of the engine traveling as a tangent to the curve, while the axles of the drivers are parallel, or nearly so, to the radical line of the curve. In the drawing I have represented my improved truck itself. The mode of applying the same to any ordinary locomotive engine will be apparent to any competent mechanic, as my truck can be fitted in the place of those already constructed, or the same may be altered to include my improvement.'

The specification then refers to the drawings, showing the wheels, the axles, and the frame of any ordinary locomotive truck, made in any usual manner, with the center cross-bearing plate or platform, of two thicknesses of iron plate riveted together, strengthened by cross-bars beneath, and embracing at its ends the upper bars of the frame; a bolster made of a flanged bar, the king-bolt passing through the center of the bolster, and also through an elongated opening in the plate, so as to allow of lateral motion to the truck beneath the bolster, and at the same time becoming a connection to hold the truck to the engine, the bolster taking the weight of the engine in the middle, and itself suspended at the ends of bars attached to the moving ends of pendent links attached by bolts at their upper ends to brackets on the frame, and the distance between the bars, transversely of the truck, slightly more than between the bolts, so that the pendent links diverge slightly. The specification then proceeds: 'When running upon a straight road the engine preserves great steadiness, because any change of position transversely of the track, in consequence of the engine moving over the truck, or the truck beneath the engine, is checked by the weight of the engine hanging upon the links, and, in consequence of their divergence, any side movement causes the links on the side towards which the movement occurs to assume a more inclined position, while the other links come vertical, or nearly so; hence the weight of the engine acts with a leverage upon the most inclined links to bring them into the same angle as the others, greatly promoting the steadiness of the engine in running on a straight line. As the pilot or truck wheels enter a curve, a sidewise movement is given to the truck, in consequence of the engine and drivers continuing to travel as a tangent to the curve of the track. This movement, and the slight turn of the whole truck on the kingbolt, not only causes the wheels to travel correctly on the track, with their axles parallel to the radical line of the curve of track, but also elevates the outer side of the engine, preventing any tendency to run off the track upon the outer side of the curve. Upon entering a straight track the truck again assumes the central position, and in case of irregularity in the track, or any obstruction, the truck moves laterally, without disturbing the movement of the engine. I do not claim laterally-moving trucks, nor pendent links, separately considered, but what I claim, and desire to secure by letters patent, is the employment, in a locomotive engine, of a truck or pilot wheels fitted with the pendent links, to allow of lateral motion to the engine, as specified, whereby the drivers of said engine are allowed to remain correctly on the track, in consequence of the lateral motion of the truck, allowed for by said pendent links when running on a curve, as set forth.'

The invention, then, as claimed, is for the combination, with a locomotive engine, of a truck, of which the king-bolt, forming the connection to hold the truck to the engine, passes through a bolster, and through an elongated opening in the plate or platform of the truck, so as to allow the truck to have a lateral motion beneath the bolster; and the bolster takes the weight of the engine in the middle, and is suspended from the frame of the truck by pendent and slightly divergent links, so that any movement of the engine or truck sidewise, as in entering upon or passing over a curve of the track, causes the links on the side towards which the engine moves to assume a more inclined position, and the other links to become nearly vertical, and the weight of the engine, hanging upon the links, checks its own lateral movement, and tends to bring both sets of links back to their original angle. In railroad cars, the trucks were allowed to swivel around the king-bolt before 1841; the transverse slot and pendent links, allowing a lateral motion, were used by Davenport and Bridges in 1841; in 1859 Kipple and Bullock made the pendent links divergent; and at the time of Smith's invention the trucks of railroad cars had all the elements of the truck put by him under the front of a locomotive engine. The question, therefore, is, whether employing, as the forward truck of a locomotive engine with fixed driving wheels, a truck already in use on railroad cars, has the novelty requisite to sustain a patent. After carefully considering the evidence and arguments in this case, and the reasons assigned for sustaining Smith's patent, in the opinion of the court below, reported in 1 Ban. & A. 470, and in the opinion rendered by the circuit court in the Second circuit, in Locomotive Engine Safety Truck Co. v. Erie Ry. Co., reported in 6 Fisher, Pat. Cas. 187, and in 10 Blatchf. 292, this court finds itself unable to escape from the conclusion that the application of the old truck to a locomotive engine neither is a new use, nor does it produce a new result. In both engine and car the increased friction against the rails and the danger of being thrown off the track, in entering upon or passing along a curve, are due to the impulse of forward motion in a direction tangential to the curve, and to the influence of centrifugal force. In the engine, as in the car, the object and the effect of the transverse slot, allowing a slight lateral motion, and of the divergent pendent links, by means of which the weight of the engine or car itself helps to keep it upon the track, and to secure steadiness and safety by lessening the friction against the rails and the danger of being thrown off the track. The only difference is, that by reason of the fixed position of the driving wheels of the engine, the truck, which has before been applied at each end of a car, can only be applied at the forward end of the engine, and therefore the accommodation of the movement of the...