(1) Gravity Carriers Old.-In point of equivalency more of the present elements, whether considered singly or in combination, are perhaps to be found in Alvey's gravity conveyer, patented in 1902, No. 714,432, than in any other prior patent. Alvey stated in his specification:

"My invention relates to conveyers for the purpose of transferring goods from place to place-such as boxes, barrels, and packages-the movement of the packages or other articles being ordinarily effected by gravity; but it is to be understood that the invention is not confined necessarily to a conveyer on which the articles are moved by that force alone. * The invention has for its objects to enable goods to be transferred from one point to another, as in a warehouse, expeditiously and with a minimum of hand labor and to allow of the apparatus being adjusted to receive goods at different points, and to deliver them at different points as may be required, expeditiously and with certainty."

Among the drawings accompanying the letters patent are the following:

*

"Fig. 1 is a perspective view showing a conveyer of portable character embodying my invention set up in a warehouse for the transfer of goods from one point to another. * Fig. 3 is a plan view of a portion of the same. Fig. 7 is a sectional view of the roller bearing. * Each of the straight sections A comprises side pieces 1, of wood or other suitable

material, united at suitable points by transverse connecting members or tie rods 2. These side pieces have formed in them or attached to them bearings 3 for the shafts or journals 4 of the transverse rollers C. The latter are spaced apart, but are sufficiently close together to enable the goods to be conveyed to pass from one roller to the next without falling through. The curved sections B are constructed on similar principles, but with inner and outer curved side pieces 5 and 6, the rollers C' of said curved sections being arranged on lines radial to the center of the curve on which the section is constructed. * * *

"It is highly important that the rollers should revolve freely under packages of relatively light weight, to which end the rollers must not be too heavy or have too much inertia. On the other hand, they must be strong enough to carry heavy weights when required. I have constructed the rollers, after much experimentation, of a material which meets both these requirements. They are made from a pulp of hard fiber of relatively light specific gravity, known as 'leatheroid.' They are thus also seamless, without grain, and not liable to crack."

As illustrative of the combinations and essential elements involved, two of the claims are copied in the margin.3

Alvey further developed the gravity carrier art through his patent of May 23, 1905, No. 790,776, under an application filed September 5, 1904. He introduced a spiral gravity conveyer adapted to carry all kinds of articles usually stored in warehouses, from any of the upper floors to the basement or shipping room, and to discharge packages at any of the intermediate floors. The spiral conveyer is adjusted to and supported by a vertical post extending through such floors of the building as may be desired, with suitable openings through which to maintain the conveyer and carry packages; in order to distribute packages at intermediate floors, gravity switches are removably connected with the spiral portions of the conveyer; provision is made for carrying articles to the spiral parts by gravity conveyers, which, as also the switches, are similar in form to the structures above shown in Alvey's patent of 1902, No. 714,432. Alvey went still farther in 1905, under an application of September 5, 1904, through his patent, No. 790,811. There he provided for lifting, instead of lowering, packages from floor to floor. The conveyer is maintained at an ascending grade and driven by power. It is to be observed of both of Alvey's later structures that the carriers are divided into sections with angle iron side rails.

Some 14 years before the issue of Alvey's first patent, Pusey secured a patent, No. 387,733, upon a structure called an "artificial toboggan or coasting hill," which is instructive in the gravity carrier art. The specification states:

"The trackway consists of a series of rollers journaled transversely in a suitable framework."

3 "1. In a portable conveyer, the combination of a plurality of sections provided with transverse rollers, and supports for said sections, the upper part of each support being hinged to the conveyer-section and the lower part of each support being adjustable on said upper part."

"6. In a gravity conveyer, the combination of a series of separately and freely rotatable rollers, and means for supporting the same to form an inclined way, said rollers being constructed with shoulders 16 and intermediate recessed portions, and adapted to automatically maintain packages in the middle of said way, substantially as set forth."

The simplicity of the structure will be seen by reference alone to some of the accompanying drawings:

"Fig. 1 is a side elevation. Fig. 2 is a plan.

Fig. 5 is an elevation of roller detached, with end view of the toboggan thereon. * a, Figs. 1 and 2, represents longitudinal frames or stringers supported by a trestlework or posts, b, and provided with bearings c, for the journals of the series of wide transverse rollers D."

The cylindrical portions of the rollers are made of waterproofed paper or strawboard, or similar light and strong material. The patentee states in his specification:

"I am aware of the fact that roller trackways for sleds are old,

in which trackway were inserted rollers or balls for the runners of the sleds to descend upon; and I do not therefore claim broadly, as new, an inclined trackway with rollers therein."

The patentee's idea of the scope of invention open to him is important and is sufficiently explained by claim 1 copied in the margin.

In 1885 Hinds & Mace received a patent on a portable chute, No. 312,468, saying in their specification:

"The invention relates to inclined slideways, and is specially adapted to transfer tiles, bricks, or similar articles from the drying shed to the kiln, or from the kiln to the yard. The slideway is made in sections, each of which has its floor composed of rollers having bearings in the sides of the sections."

Palmer obtained a patent in 1888, No. 376,340, on an elevator, which may properly be regarded as a distributing contrivance; it was designed for carrying goods or other materials up or down in a warehouse, store, manufactory, or other similar place of business, and automatically

4 "An artificial coasting course or toboggan slide, consisting of the combination of the inclined longitudinal frames or stringers, the supporting frame or trestlework, and the series of rollers journaled in and between said stringers, adjacent to and out of contact with each other, substantially as and for the purpose set forth."

delivering them at different floors or stations, and there depositing them upon an "inclined series of rollers" disposed transversely between parallel side rails, whence they were moved by gravity to the place desired; the particular use illustrated by the drawings related to the manufacture and handling of bricks.

(2) Metal Side Rails and Rollers.-It will be noticed that none of the prior patents thus far considered in terms calls for metal rollers; but it is to be remembered that the last two Alvey patents mentioned call for metal side rails. Assuming that a change of material, say from wood to metal, was important in a frictional sense or otherwise, there were kindred power-driven conveyers which, expressly provided for metal rollers; and we think such conveyers may fairly be treated as part of the prior art in question. They are certainly of a closely analogous art. Holman provided for the use of metal rollers in 1885 in his power-driven railway track layer, patent No. 315,034. He fastened to the outer sides of cars a sectional tramway, comprising parallel side rails, called "parallel bars," with transverse metal rollers journaled in the bars. The rollers were used to convey ties and rails from the cars to points in front of the train in the line of the proposed railway construction. Again, in Hanna's carrying roll, patented October 28, 1902, No. 712,061, we find a design for metal tubular rollers of uniform diameter, with integral journal portions, which are intended as carriers of belts for "elevators, conveyers, and similar classes of machinery." The patentee made no provision for side rails or other familiar bearings upon which to operate his rollers as carriers; nor was such omission unusual. See, for instance, the carriage with rollers in the brick and tile machine of McKenzie, patented in 1878, No. 203,284, and in Aiken's feed table for rolling mills, patented in 1890, No. 439,925. Further, Alvey emphasized in the portion of his specification above quoted the importance of rollers that would revolve freely under packages of relatively light weight and yet be strong enough to carry heavy weights when required; and he says that "after much experimentation" he adopted a material for rollers called "leatheroid," which was "seamless, without grain, and not liable to crack." Pusey had pointed out years before, that rollers might be made of "suitable light material," saying that the "ease with which the inertia and friction of the rollers are overcome * * * of course depends mainly upon the weight" of the rollers. He preferred "compacted waterproofed paper or strawboard," and as we have seen used such rollers in his gravity toboggan. The experience of Alvey and that of Pusey as expressed by each in his specification, and more particularly the use made of the metal rollers as above stated, were manifestly suggestive of the adoption of metal rollers for gravity carriers. Wright v. Tobacco Co., 252 Fed. 146, C. C. A. —, decided by this court August 3, 1918.

(3) Stationary Axles with Revolvable Rollers.-Appellee points out a difference between the patents in suit and the gravity conveyers of

5 Alvey's roller metal journals and metal bearings with oil-retaining chamber 22 to lubricate them, are another important feature to be observed. They are illustrated in Figs. 7 and 8 of his drawings, supra.

the prior art as respects the relations between the axles and rollers of the two sets of structures. True, as we have seen, the axles of the former are stationary and the rollers with ball bearings revolve upon them; while the rollers of the latter have rigid and axially connected journals which are mounted on bearings in the side rails and revolve with the rollers. Apart from the ball bearings of the patents in suit, considered later, the plan of an exterior roller (composed of "sleeves") distinct from an interior part axially carried by side bearings was shown, for instance, by McKenzie in 1878 in his brick and tile machine before pointed out. Holman, above mentioned, provided metal rollers with annular flanges at their ends; but he also stated in his specification that he "proposed to make these rollers hollow, and of metal, and to mount such construction of roller on a stationary axle which passes through the closed ends of the roller, whereby the bearing is entirely at the ends of the roller." Perhaps the commonest examples of this latter construction are found in the ordinary road wagon, having rigid axles and spindles with hubs turning upon the spindles, and in the idle wheel to which a belt is shifted when not in use for transmission of power, while the bicycle furnishes a complete illustration, as for instance, the Douglas bicycle, patented in 1892, No. 469,627. (4) Sectional Carriers.-In view of what has been pointed out it is scarcely necessary to allude to this feature of the patents in suit. We have seen that Álvey's patent, No. 714,432, divides the carrier into sections with "firm connection of the various sections end to end," the connecting parts being described in the specification and shown in the drawings; this in substance is true of Alvey's patent, No. 790,776, of the Hinds & Mace patent, and also of the Spence portable conveyer, Pat. No. 779,139. We do not stop to consider the horizontal and diagonal braces of the sections, because such bracing is familiar in structures of everyday use, such as the ordinary stepladder, trestle or scaffold.

(5) Notched Frames.-It is contended that the patentee of the second patent in suit "introduced for the first time the feature of the slotted side rails whereby any through shaft and roller could be removed separately." This is to overlook Winter's provision of the same character in his skid for moving rails, patented September 19, 1905, under application of 1904, No. 799,699. The rollers are there. mounted in open slots and, as his specification states, "may be easily removed when broken or worn out and replaced by others." Such slots or notches were old when Winter adopted them. The drawings of the McKenzie patent of 1878, before cited, plainly show notches in the upper edges of the side bars in which the rollers were journaled, though the patentee does not seem to have thought it worth while even to mention the notches in his specification or claims. However, the notches must be regarded as "described" in a "printed publication" within the meaning of the patent act (Keene v. New Idea Spreader Co., 231 Fed. 701, 708, 145 C. C. A. 587, and citations [C. C. A. 6]); this is true of the drawings of Aiken's and Spence's patents, supra. Apart from Winter, these patentees do not state, though it is manifest, that the notches shown were designed in part to admit of separate