(after stating the facts as above). [1] Hay-slings w;ere old, and the ’ art was well developed, in fact crowded, before Louden applied for the patent in suit. Without detailing the prior art, it is enough for present purposes to say that the public or other men than Louden were entitled to combine the following elements, broadly considered: A track; a stop on the track to engage the upwardly-extending arms of a dog; an upper frame adapted to run on the track and supporting the dog in slots to permit an up and down motion; a lower frame swiveled to the upper frame;'and *755pulley-supporting mechanism carried by the lower frame and adapted to interact with the dog in locking the pulley in an elevated position.
A filler is the strongest prior art reference. But appellee’s post art illustrations of modifications of Bouden’s patent and of Miller’s structure (rendering the latter inoperative, appellant contends) are still stronger. Yet even against them, what Bouden actually discovered in a field so pre-empted that he could hardly move without treading on others’ toes, may readily be perceived. Pull the lower end of Miller’s pivoted arm K or of Bouden's pivoted arm N to the left, and the part of the arm below the pivot swings under and supports the pulley block. As the upper part of Miller’s0arrn moves to the right, it pulls along the horizontally sliding bar /„ until the pin projecting clown from the base of the dog M drops into the hole e in the sliding bar, thereby locking the pul3e}r in its elevated position. As the upper part of Bouden’s arm moves to the right, its curved end supports the dog until the latter drops and its peripheral surface engages the inner side of the upper part of the arm (at the junction of N' and AT2), -thereby locking the pulley in its elevated position. Booking the pulley in its elevated position was a result necessarily common to all of the many preceding successful hay-carriers. In a general sense they all attained that result by the interaction of a “clog” and a “pullev-supporting mechanism.” Miller’s way, as already stated, was the nearest to Bouden’s. Now in Miller’s, if the pivoted lever K be considered the "pulley-supporting mechanism,” then the piece M and the horizontally Aiding bar Z, must be taken as jointly constituting the “dog.” If the piece M, which is actually the “dog,” be accounted such, then the pivoted arm K and the horizontally sliding bar B must jointly be accepted as Miller’s “pulley-supporting mechanism.” But whatever nomenclature be applied to Miller’s combination, the fact is patent that the locking result is secured by the interaction of three parts, K, B, M, which must be separately manufactured and then assembled so that each may have a free movement of its own. That is, there is no way by which K and B, or B and M, can be made integral or can be fixedly attached to each other without rendering the Miller device inoperative. By calling two parts one the fact is not changed that operativeuess requires thive separate and distinct parts. Bouden, however, accomplished with two parts, in fact as well as name, what his most progressive predecessor took three to attain. Essentially the vice of appellee's comparison lies in the implication that what may be found in Miller's structure to be his “pulley-supporting mechanism” must therefore he the “pulley-supporting mechanism” of Bouden’s claims. Beneficent utilities, in the way of fewer {¡arts to make, less work in assemblage, greater compactness resulting in savings of material and labor, increased certainty and ease of operation, are all apparent. If doubt existed that invention was in play in producing the direct swivel connection between the dog and the grappling hook to lock the pulley in its elevated position, it would be removed by the ten years wait, commercial success, and competitors’ adoption of the disclosure.
[2] Is infringement avoided by making the base of the dog solid? Each claim calls for a “dog having an annular lip,” and if the base of the dog; is solid, there is no “'annulus” or ring, the argument runs. *756But the quotation from the claim is not exactly accurate. It is not a dog having a ring base to which is ascribed the function recited in each claim. No office is performed by the hole in the base. Every purpose of the patented device would as well be served if the hole be filled. In the claims the “dog” is limited by its described relation with the “pulley-supporting mechanism.” That is, the “dog” of the claims is-not a dog with a functionless hole in the base, but a “dog having an annular lip adapted at all points on its circumference to engage the pulley-supporting mechanism.” Looking to the structure and operation described in the specification, it is seen that, when the dog is in its upper position, only the outer edge of the circular base functions with the grappling hooks; and, when the dog is in its lower position, only the peripheral surface functions with the grappling hooks. Elements in claims should be read with reference both to the structure and the function given in the description of the invention. Dictionary definitions should not be applied to words in claims if the patentee in and by his drawings and descriptions of parts and functions has clearly supplied his own dictionary. General Electric Company v. Richmond Street & Interurban Railway Company, 178 Fed. 84, 102 C. C. A. 138; Chicago Woodenware Company v. Miller Ladder Company, 133 Fed. 541, 66 C. C. A. 517. In the latter case we said:
“In both claims it is evident that Miller differed with Webster and others as to the definition of a trestle. But, for all that, he should not be deprived of protection in his invention any more than for mistakes in orthography-provided he did not misspell beyond recognition of the sense.”
And when regard is given to Louden’s disclosed invention, namely, .the direct swivel connection, the interaction between the grappling hook and, first, the outer edge of the dog’s circular base, and, second, the dog’s peripheral surface, not only is the meaning of the claims clear, but the term “annular lip” does not seem particularly inept. Whether the “annular lip” be supported in its functioning position by a dog having a solid body or a skeleton frame is immaterial to the actual invention disclosed and claimed. Form is material only so far as it is essential to the operation, or indispensable, by reason of the state of the art, to the novelty of the claim. Adam v. Folger, 120 Fed. 260, 56 C. C. A. 540. Here, neither operativeness nor prior art required the base of the dog to be cut out. Direct swivel connection between dog and grappling hook is Louden’s property; and it has been unlawfully invaded by appellee.
Claims 3 and 4 call for “a pivoted hook or arm” to engage and support the pulley-block. Appellee uses a two-hook sidehold structure as his means for grappling and sustaining the pulley-block, and contends that he escapes these claims because they are limited to one hook or arm. First: Louden’s patent shows two supporting arms, N and P. He states how, if the catch P be discarded, the carrier should be reorganized. He therefore disclosed that the invention of the direct swivel connection could be utilized with pulley-supporting mechanism of either one or two hooks or arms, preferably two. . Second: In the prior art the one-hook underhold structure and the two-hook sidehold *757structure had both been used in hay-carriers as the pulley-supporting mechanism. Hoffman’s patent, No. 167,763, two-hook sidehold; _Miller’s patent, No. 288,839, one-hook underhold. And Louden said in his specification that it was evident that his dog could be used with "any kind of pulley-supporting hook or catch adapted to co-operate with said annular lip,” and that he did not wish “to be limited to the exact form of pulley-support set forth.” Finally: The word “a” is primarily the indefinite article. From the preceding considerations, we judge that the word was used in these claims as the indefinite article and not as a synonym of the definite numeral one.
The decree is reversed with the direction to enter a decree in appellant’s favor for an injunction and an accounting.