(after stating the facts). The prior art, as disclosed in this case, taught Mayr how to construct a curtain-stretcher with bars that formed an adjustable frame; how to rabbet the bars and cut the T-shaped slots; how to fashion a pin-base that was held hy the slot, was movable along the slot, and carried the pin-point outside of the slot; and how to bend a single piece of wire into a pin, including both the shaft and the base.
This wire pin, as a pin, was covered by the patent to Chess; but none of the prior patentees (Backof, Osgood, Wisner) who used pins held by and movable in the slots had tried the Chess pin in the rabbeted and slotted stretcher box. So Mayr made this claim:
“A ourtain-stretolier bar, having a rabbeted upper edge; a T or similarly shaped slot ojieuing on the said upper edge; a pin having a liase stamped out of the same piece of wire, made movable therein, substantially as shown and for tlio purpose set forth.”
But all of these elements were old, and old, too, was the combination of the rabbeted and slotted bar with certain movable pins. Consequently, the examiner took the view that no invention was required to *182substitute the Chess pin for one of the others in the slotted bar. Mayr then amended the claim to read:
“In combination' with a curtain-stretcher bar, a movable pin with a base stamped or formed out of a single piece of wire, and so constructed that the said pin will stand perpendicular to said base, substantially as shown and for the purpose set forth.”
But this claim as amended was just as plainly for the Chess pin in the Backof bar. So it was rejected, and that decision was affirmed on appeal to the examiners in chief.'
The other two claims in Mayr’s original application were also rejected by the examiner. They came before the examiners in chief in substantially the form in which they appear in the patent, except this, that the wording of the claims in the patent, “the base of said pin and the slot being so proportioned that when tilted such base will bear against both sides of the slot, thereby preventing the sliding of the pin,” has been substituted for, “the pin made movable in said T-slot in such a way that the pin will be drawn against the side of the T-slot when the curtain is stretched upon it, thereby preventing the sliding of the pin when in use.” The rejection of these claims was also affirmed by the examiners in chief, but they suggested that they would recommend an allowance of the claims if amended so as to specify distinctly that “the base of the pin and the slot are so proportioned that when tilted such base will bear against both sides of the slot, thereby preventing the sliding of the pin.” • Mayr thereupon made the suggested amendments and took out the patent.
The file-wrapper and contents, together with the reference patents, thus make clear exactly what Mayr did. He took the combination of a stretcher bar, a rabbeted edge, a T-shaped slot, a wire pin with its base within the slot and its point projecting out through the lips of the slot (a combination which he agreed, by acquiescing in the rejectionss was open for any one to use), and improved upon it by so proportioning the base of the pin and the slot that when a curtain should engage the projecting point the base would tilt, and its respective edges would bear against the opposite sides of the slot, “thereby preventing the sliding of the pin.” The proportioning of the slot and base to obtain the slide-preventing tilt is the only feature that can give vitality to the patent, and in order to appreciate the force and bearing of the proceedings in the patent office, that feature of the claims must be read in connection with the description and drawings. The description says that “the pins are made to move freely in the slot.” The drawings show a very distinct tilting — as much as 10 degrees — and while they are, of course, not to be taken as working plans, nevertheless the description and drawings, together with the history of the claims, require such a looseness in the slot that there shall be a distinct and intended ti'ting of the base to secure the specified result.
Appellees insist that the proportioning of the base and slot to obtain the slide-preventing tilt cannot sustain the patent, because it was present in the earlier devices. The Backof patent is probably the strongest reference, outside of Mayr’s disallowed claims. Backof’s pin points project from wooden blocks, which are held by and are movable along *183the slot or groove. The specification requires the blocks to “work freely in the groove,” but apparently only to the extent necessary to enable the blocks to be slidden into place readily. There is no hint in the description or drawings or claims that there shall be a distinct and intended play between the base and the slot in order to obtain thereby a further or new result. On the contrary, the patent indicates that such a thought was entirely absent from Backof’s mind. The wooden block was to be fitted as snugly into the slot as possible, without preventing the user from moving it readily; and so with the device of Mayr’s claim, which was totally rejected. It was offered as an improvement upon .Rackof’s bar. But because the known wire base was to be substituted for the known 'wooden base, and be fitted into the slot in the known way, the claim was rejected. '
We cannot give to the Backof patent and to Mayr’s rejected claim a construction to sustain infringement different from that put upon them to avoid anticipation. Now, if upon Backof’s snugly fitting block a prying strain be put by-means of the projecting pin shaft as a lever, there will necessarily he a binding effect, in the nature of a tilting of the base within the slot, and as Backof required the blocks to “work freely in the groove,” there might be a barely perceptible tilting; and this is found in the Backof exhibit. But the binding was rather to be avoided than sought, like the binding of rings upon a curtain pole, where freedom of movement is the object; and the record satisfies us that not only was there no distinct and intended tilting, but also that the binding caused by the strain of the curtain was not sufficient to lock the pins in place.
Mayr improved upon Backof by substituting a wire base for the wooden block; but this improvement was open to every one’s use, as Mayr confessed in the patent office. There is no exhibit of Mayr’s rejected claim, but it is quite evident that if upon the snugly fitting wire base a prying strain be put by means of the projecting pin shaft as a lever, there will necessarily he a binding effect, in the nature of a tilling of the base within the slot. And as it is a requirement of every stretcher bar with movable pins that the pins he free for adjustment by the user, there might be a barely perceptible tilting. Nothing has been shown in evidence to prove whether the bite of the wire base of Mayr’s rejected claim on the wooden bar, caused by the strain of the curtain, would or would not be sufficient to lock the pins in place.
To sustain the validity of the allowed claims as amended, we must hold that the distinct and intended titling was not anticipated by the unsought and unavoidable binding or tilting of the Backof patent and Mayr’s rejected claim. So infringement can be predicated on nothing less than such a proportioning of base and slot as will charge appellees with using a distinct and intended tilt to prevent sliding. Mayr could not monopolize the result. If that -was not already attained in Mayr’s disclaimed improvement, appellees were free to use that improvement, with its unsought and unavoidable binding, and proceed therefrom to the result of a curtain-locked pin by any means other than using the distinct and intended tilting of the claims in suit. In the Hoffheins patents and in the exhibits of appellees’ stretcher bar the result is obtained by adding to the unavoidable binding in Mayr’s rejected claim the friction that *184comes from making the base normally wider than the slot, and bending the shaft so that it bears upon the outside of the lip of the slot. We disagree with appellees’ contention that the spring-base alone locks the pins when the curtain is put on the stretcher. On the spring-side o.f the base there is the combined friction of the spring and of the unavoidable binding that obtained in Mayr’s rejected claim; and on the other side the total friction is divided between the unavoidable binding within the slot and the intentional bearing of the bent shaft upon the outer surface.
At the bar appellants called attention to the fact that appellees’ exhibited pins were made of wire that would not retain its spring. Even so, the pins would at least fill, the slot as completely as in Mayr’s rejected claim.
The presumption which, in view of the state of the art, arose from the grant of the Hoffheins patents, accords with the facts of the record in supporting the conclusion that Mayr and Hoffheins started from common ground, and each made an independent advance. Compare Milwaukee Carving Co. v. Brunswick Co., 126 Fed. 185, 61 C. C. A. 175, and Loew Supply Co. v. Fred Miller Co. (C. C. A.) 138 Fed. 889.
The decree is affirmed.