Standard Stoker Co. v. Berkley Mach. Works & Foundry Co.

106 F.2d 475, 42 U.S.P.Q. (BNA) 490, 1939 U.S. App. LEXIS 3020
CourtCourt of Appeals for the Fourth Circuit
DecidedAugust 28, 1939
DocketNo. 4477
StatusPublished
Cited by1 cases

This text of 106 F.2d 475 (Standard Stoker Co. v. Berkley Mach. Works & Foundry Co.) is published on Counsel Stack Legal Research, covering Court of Appeals for the Fourth Circuit primary law. Counsel Stack provides free access to over 12 million legal documents including statutes, case law, regulations, and constitutions.

Bluebook
Standard Stoker Co. v. Berkley Mach. Works & Foundry Co., 106 F.2d 475, 42 U.S.P.Q. (BNA) 490, 1939 U.S. App. LEXIS 3020 (4th Cir. 1939).

Opinion

SOPER, Circuit Judge.

This appeal involved four patents relating to automatic stokers for coal-burning railroad locomotives. Plaintiff, who is the largest manufacturer of such stokers, has marketed two types, conveniently termed type A and type B. The general principles of both types of stokers are quite old and beyond the protection of any patents. The four patents in question are for specific parts in the construction of these stokers and for such specific parts in combination with other parts, as hereinafter explained.

The type A stoker consists of a horizontal conveyor screw, running in a trough beneath the locomotive’s tender, whereby the coal is carried forwardly to a transfer hopper, from which the coal is raised by two vertical or elevator conveyor screws, and means for dispersing coal from the top of the vertical conveyor screws to within the fire-box. The vertical screws rise at an incline from each other from the forward end of the horizontal screw to points on each side of the fire door. Because there is such a vertical conveyor on each side of the fire door, this type of stoker is generally called the “Duplex” type. These are the principle features of this stoker, but, of course, there are many other parts such as casings for the conveyors and mechanical means for operating them.

This type A stoker operates in the following manner: The coal falls by gravity through an opening along the bottom of the tender upon the horizontal conveyor screw and is carried forward by its rotary action to a point at the rear end of the locomotive’s boiler. Here the coal is forced upon the vertical conveyor screws which by their rotary action raise it to points on either side of the fire door. From the top of the elevator screws, the coal is blown by steam through some form of distributor tube or nozzle to all portions of the firebox.

The plaintiff company constructed over 7,000 of these type A stokers, which are [476]*476still in use, but since 1931 it has manufactured almost exclusively the less complex type B stoker. There are approximately 4,000- of the latter in use on railroad locomotives.

The type B stoker resembles the type A in that it consists of a horizontal conveyor screw running in a trough beneath the tender, but the screw in the type B runs forward to a point beneath the firebed, and in place of the two vertical conveyor screws, there is a single unobstructed conduit or casing which forms an elbow at the forward end of the horizontal conveyor and rises thence vertically inside the boiler to a point above the fire. There are steam jets at the top of the vertical riser to scatter the coal over the fire.

The first patent is Lower patent No. 1,373,748. It calls for all the old principles and parts of a type A stoker with the single novel feature of an enlarged final flight or turn on the forward end of the horizontal conveyor screw. The purpose of the change is thus stated in the specification: “It is common practice for the fuel to be transferred from the tender to the locomotive by means of a screw conveyor working in a trough and conduit located below the tender floor and delivering to' a chambered body carried by the locomotive, from which it 'is elevated by one or more similar screws. It is important to the efficient working of the elevating screws that the fuel be under pressure as it is taken up and carried forward by them, thereby reducing the frictional action upon it of the vane of the elevating screw. It is, nevertheless, desirable that there be a free movement of the fuel in the horizontal or transferring conduit.” This patent is hereafter referred to as the “Duplex” patent.

The second patent is Lower patent No. 1,455,058 which also relates to type A stokers. This patent refers to the distributing tubes or nozzles through which coal is discharged by steam jets from the tops of the vertical or elevator screws into the firebox. The tubes extend from the upper ends of the elevator screws into the firebox and are provided with upper and lower forwardly projecting plates. The- bottom plate has an upstanding traverse lip or abutment on its forward end with laterally opening recesses immediately back of thijs abutment. The object of the patent is to provide a means for scattering the coal throughout the firebox when it is shot through the tube leading from the top of the vertical screws. The. upper strata of the coal passing through the distributor tube spreads out into a fan-shaped stream feeding the forward end and cornel's of the firebox; the lower strata strikes the abutment or lip on the forward end of the lower plate, bounces generally backward into the laterally opening recesses immediately back of the abutment, and rolls down these recesses as in a chute to the rear and rear corners of the fire box. This patent is hereafter called the “distributor tube” patent.

The third patent is Hunt patent No. 1,690,116 and relates to the type B stokers. The specification states: “In conveyors of this type and particularly those wherein the coal is moved beyond the end of the screw conveyor, upwardly through an unobstructed conduit to a point above the fire and is there distributed over the fire by steam jets, if the-conveyor screw at its forward end has only a single thread or flight, the delivery of the total from the mouth of the conduit is intermittent rather than continuous. The coal moves upward during a portion of each revolution of the screw and remains stationary during the remainder of the revolution. Continuous delivery of coal to the fire box is desirable and the main object of the present invention is to provide means for effecting this result. For this purpose, I provide the conveyor screw at its forward or delivery end with a plurality of threads so positioned as to produce a continuous delivery of coal through the upwardly extending conduit.”

The District Court’s finding that each member of the combination described in the claim is o'ld in the art of type B stokers except for the sole novej feature of having a plurality of threads at the delivery end of. the horizontal screw, . accurately describes this patent, hereafter called “double thread conveyor screw” patent.

The fourth patent is Hunt patent No. 1,724,593 and also relates to type B stokers. The specification states: “In stokers of the type where coal drops by gravity from a coal bin into a screw conveyor where it is engaged by the conveyor screw and moved forward, the conveyor screw may not operate effectively on a lump of coal that has a linear dimension greater than the pitch of the screw, because the screw can not get hold of it to move it. The main object of my invention is to improve the- construction of the conveyor screw [477]*477at the points where it receives coal from the bin so that it will effectively engage unusually large, as well as smaller, lumps of coal and move the same.”

The sole improvement or novelty consists of a number of notches or projections on the thread of the horizontal conveyor screw which projections are provided with sharp radial edges adopted to engage and crush large pieces of coal. The District Court’s finding that this patent is an old type B stoker with notches on the horizontal conveyor screw accurately described it. This fourth patent will be referred to as the “notched conveyor screw” patent.

The defendant operates a general machine shop and foundry, and in the latter part of 1927 commenced to manufacture and sell to railroads unpatented parts to be used for maintenance and repair of locomotive stokers which had been sold to the 1 railroads by the plaintiff.

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Cite This Page — Counsel Stack

Bluebook (online)
106 F.2d 475, 42 U.S.P.Q. (BNA) 490, 1939 U.S. App. LEXIS 3020, Counsel Stack Legal Research, https://law.counselstack.com/opinion/standard-stoker-co-v-berkley-mach-works-foundry-co-ca4-1939.