It does not, therefore, seem proper that applicants should now, for the first time, of the many possible arrangements of springs, select, describe, and claim the only one which could cover the usual location of the springs in a spring rocker. Several of the criticisms herein made would, in an ordinary case, be comparatively unimportant, but in this case they must be gravely considered, because the enlargements proposed by applicants consist of several small changes per se, which, taken together, entirely reorganize the original invention."

The new drawings were changed to accord with those accompanying the original specifications, and the expression "tilting or rocking chair," as used in the original specification, was substituted in the claims. Other changes required by the examiner were made. The applicants, however, protested that in doing so they did not mean to narrow their claims, and expressed their astonishment at the rulings of the examiner. In a subsequent letter the examiner comments on the fact that, although astonished, the applicants recognized their force by recasting their specifications and claims so as to avoid the objections made. To this applicants replied: "Applicants respectfully dissent from the suggestion of the examiner that they have recognized the force of any of his actions, 'if not by words, by recasting this case so as to avoid the objections made.' Instead of this, in their desire for peace, they have merely recognized the propriety of using different forms of expression, not open to criticism even in a most refined view, to convey exactly the same meaning intended to be conveyed before. For instance, the examiner objecting to the expression 'platform rocking chair (notwithstanding the claims of the original application, as approved by the former examiner and all of the examiners in chief, employ the terms 'platform,' 'rocking,' and 'chairs'), applicants have erased these words, and used others to express exactly the same idea; and substantially the same is true in reference to base rails and other expressions. Not believing in any magic in words, or in the necessity of calling a chair a rocking chair in order to make it one, applicants have not intended by any verbal or formal changes to limit the scope or meaning of their claims now presented; and in all frankness they do not wish any other amendments to be so considered or understood. On the contrary, they do not consider that either of their claims is limited to special forms or details of construction, or to any particular kind of chairs, except, of course, chairs having rockers on the under side of the seat part, and corresponding rocker supports the base part; and, in case this division be passed to issue, they desire it to te done with this understanding: that they intend its claims to cover, and understand them as covering, all forms of chairs having rockers and rocker supports to which their two-spring connection can be properly applied. This is exactly what they intend to say by the second paragraph preceding the claims of their substitute specification filed October 1, 1885,-the paragraph beginning, 'As the pecular form,' etc., to which the examiner excepts; and it is exactly what they now intend to say by the paragraph since substituted in its place. Everything applicants have said or done, then, in the way of 'recasting this case so as to avoid the objections made,' has been in the line here suggested, but not with any thought of recognizing the force or soundness of such objections. In fact, as heretofore said, applicants consider their present specification and claims at least as broad as those first presented in this division. They now cover all kirds of chairs contemplated in their original application, platform rocking chairs, of course, included." To this the examiner replied: "With respect to the construction put on certain expressions used in the description by applicant in the argument attached to the substitute specification, it is sufficient to say that the office, of course, cannot govern the construction that applicant or any one else may put on the description, the terms used, or the claims. The office can simply prevent the use of improper tems in a substitute specification, which has been the aid in this case." To this the counsel for the applicants responded: "We understood the examiner's closing statement as meaning that the changes in language which have been heretofore made have been simply intended to prevent the use of improper terms,' and therefore that the office understands them in the sense intended, and as heretofore explained."

After this the examiner required the applicants to insert in the description in the specifications of the chair to which the applicant's device was applied words

showing that the rockers were attached to the seat part of the chair "by a spider," and also these words contained in the original, "and, to prevent the springs bending or rubbing, the edges of the box forming the rockers should be a somewhat greater distance apart than the sum of the two diameters of the two springs," in order to show that the springs were not wide apart, as in a platform rocker, but were near the center. The applicants accompanied these amendments with the following letter: "It being understood that applicant's present claims are not limited to special forms or details of construction, we insert the above amendments simply to make the specification conform to the original description, from which we have never desired or intended to depart materially. In this view we simply intend the words, 'by a spider,' constituting the first insertion, as descriptive of the drawings; but the intentional and deliberate omission of these words from the claims will, of course, prevent any construction limiting the use of the invention to a chair having the rockers secured to the seat part by a spider. Instead of this, these claims are still intended and understood as covering a chair in which the rockers are secured in any ordinary way; as, for instance, in platform rockers. And, in substance, the same is true in reference to the insertion relating to the width or distance apart of the rockers, this being merely intended to show that the rockers must be wider apart than the springs, so as to be on the outside thereof."

In the course of the proceedings, the applicants did succeed in making some changes in the language of the specifications from that used in the original, but, so far as appears from the file wrapper and contents, the patent-office examiner never modified his ruling in respect to the scope of the invention, to wit, that it did not cover the use of springs on a platform rocker. The specifications as allowed stated the object of the invention to be: "To provide a chair consisting of a seat having rockers secured to its under side, and a base having a lower support for said rockers, with two connecting springs, which shall be of sufficient strength and tension to securely connect the base and seat parts together, and hold the rockers in firm alignment with their lower support, so as to prevent the said rockers from slipping forward or backward or sidewise thereon." The specification continues: "In the drawings we have shown our invention as applied to a revolving office chair provided with rockers secured to the under side of its seat part by a spider, and a lower support therefor on its base part; and in these drawings A indicates the chair seat, B the base, E the upper rockers, F the lower support or rockers on which the upper rockers rest and move, and G the connecting springs. The rockers may be of cylindrical box form; or the sides of the boxes, the edges of which form the rockers, may, if desired, be parallel or otherwise arranged. The edges of the upper and lower rockers may be curved reversely,—that is, both of the upper rockers from a center above and both of the lower rockers from a center below their line or point of contact; or one, the upper or lower, may be curved, and the other present a straight or other line on its edges. It is obvious that in a strict sense only the upper rockers actually rock, the other or lower ones being stationary, and serving as one form of the lower support' for the upper rockers, the other form being the flat plate shown in Figs. 2 and 3. The two connecting springs are to be placed and secured in or near the center of oscillation and at off-center points,—that is, at the sides of the chair center, instead of in its front or rear.--and, to prevent the springs bending or rubbing, the edges of the boxes forming the rockers should be a somewhat greater distance apart than the sum of the two diameters of the two springs. The springs are arranged with their longitudinal axes vertical, and their ends rigidly attached to the seat and base parts of the chair, so as to hold the rockers in their proper relative position; and by their resisting the rocking motion in one action or direction and assisting it in the other an easy, comfortable, and agreeable motion is produced, closely resembling that of an old-fashioned rocking chair, and wholly different from the abrupt jerk of a pivoted tilting chair and the swaying motion produced in a seat oscillating on long plate-springs. As shown in Figs. 1 and 4 of the drawings, each of the springs is attached directly to the top of the rocker box, k1. As shown in Figs. 2 and 3, they are each secured to a bracket, k, projecting from the side of the rocker; and, as shown in Fig. 6. they are secured by clamps or clips. Each of the ends of the wire forming the

spring may be parallel with the coil next to it, as shown in Fig. 6, to avoid making any short bend in the metal; and, however the coils end, the connecting devices must always be such as to rigidly secure the springs to the seat and base parts of the chair, respectively. The two springs, arranged as described, constitute the connection between the seat and base parts of the chair for holding the rockers and their lower support in alignment and proper relative position. It is necessary, therefore, that they be of sufficient dimensions and strength to hold such parts together, and prevent lateral and longitudinal slipping of the rockers without the use or aid of guides or similar appliances. The springs, thus forming the connection between the upper and lower parts of the chair, not only dispense with the use of guides, etc., but also regulate or control the rocking motions by their elasticity and strength. When the chair seat is tilted or depressed in the rear, the upper rocker will roll upon the lower, and the springs will bend, their coils opening slightly in front and correspondingly approaching in the rear (see Fig. 4), the motion thus produced being an actual rocking motion upon a changing fulcrum, differing wholly from the motion of ordinary tilting chairs, in which the movement is on a pivot forming a fulcrum of fixed position. The backward rock is resisted by the tendency of the springs to retain their normal position, and the forward motion is assisted by the same tendency; the result being a motion unapproached by that of any tilting or oscillating chair with which we are acquainted. The essential idea or feature of our invention being the connecting together and holding in proper position of the seat and base parts of a chair having rockers secured to the under side of its seat part, and a base having a lower support therefor, by two spiral springs located at opposite sides of the chair center, we of course do not wish to be understood as limiting ourselves to special forms or details of construction, or in any way as waiving the use of proper equivalents.

The use of two springs at off-center points is a material improvement over the use of a single spring, for the reason that it is difficult, when a single vertical spring is used, to secure it to the seat and base parts so as to prevent the slipping or turning or relative derangement of the rockers and lower support. In such case the spring is practically a pivot, around which it is difficult to prevent the seat part of the chair from turning when the ordinary character of fastening is used, such as are manufactured rapidly and in large quantities as a trade-fitting or article of hardware. We do not herein claim any special or particular means for effecting the rigid connection of the springs with the upper and lower portions of the chair, our invention being directed to the feature of applying the springs so that they will constitute the connection between the upper and lower portions of a chair for holding the rockers and their lower support in alignment and proper relative position, as pointed out in the claims. Nor do we herein claim the use of a single spring as the connecting medium between the upper and lower portions of a chair for holding said parts in alignment and proper relative position, as this feature, with others, is covered by the generic claims of our application filed July 30, 1880, No. 14,470, of which this is a division. We claim: First. The combination, in a chair, of a seat having rockers secured to its under side, a base having a lower support for said rockers, and two spiral springs rigidly connected to said parts, respectively, and located and secured at opposite sides of the chair center, and constituting the connection between the seat and base parts of the chair for holding the rockers and their lower support in alignment and proper relative posijon, substantially as described. Second. The combination, in a chair, of a seat having rockers secured to its under side, a base having a lower support for said rockers, and two spiral springs rigidly connected to said parts, respectively, and located and secured at opposite sides of the chair center, and in the center of oscillation of the chair seat, and constituting the connection between the seat and base parts of the chair for holding the rockers and their lower support in alignment and proper relative position, substantially as described."

The circuit court held the patent valid, found that the defendant infringed, and entered a decree for an injunction and damages in complainant's favor.

Miner G. Norton, for appellant.

Ephraim Banning, for appellee.

Before TAFT and LURTON, Circuit Judges, and HAMMOND, J.

TAFT, Circuit Judge (after stating the facts as above). If the specifications and claims of the patent were to be given effect without regard to the history of the art or the proceedings in the patent office, it might be conceded that the defendant's device would come within the scope of complainant's monopoly. We must, however, use both aids in construing the patent.

It is claimed that the essence of complainant's patent is the use of a strong spiral spring rigidly attached to the rockers and base, to assist and resist the rocking motion of a rocking chair, and to keep the rockers in proper alignment with the base on which they 'rock without the aid of stops or other devices. It is conceded that before this invention spiral springs had been used to connect the rockers with the base of a rocking chair, but it is said that the springs had never been made strong enough, and had never been rigidly enough secured to the rockers and base, to keep the rocker in proper alignment without the use of stops or other devices. It must be admitted from this statement of complainant's invention that it covers quite a narrow field. The strengthening of the spring, and the increase of rigidity with which it was attached to

the rockers and base, may have involved invention, but it so nearly resembles a mere increase in the physical strength of an already suggested means of performing a known function that it is certainly not a pioneer or primary invention, or one the scope of which the courts would be inclined to enlarge beyond what is exactly shown in the patent. It is not a patent in the construction of which any liberal doctrine of equivalents will be applied.

The history of the proceedings in the patent office, and the direct evidence of one of the inventors himself, convince us that when the patent was applied for the inventors had no idea of applying the spiral spring to a platform rocker. They were engaged in perfecting an office tilting and revolving chair. They had first invented a chair in which a spiral spring formed the sole support of the spider and seat, and then, to prevent lateral motion in this chair, they inclosed the spring in a small rocker box, the spring still remaining the main support of the spider seat and occupant. For four years they pressed for a patent for such a device. Their main invention embraced a single spring placed beneath the center of the chair, and forming part of the pivotal bearing on which the seat moved. The suggestion of two springs was merely incidental as a substitute for one spring, and they were manifestly intended to be used in the same way at the chair center. It is very certain that the Connollys never put spiral springs on a platform rocker, and never claimed to have invented such a use, although it appears by Bunker's affidavit that even before they filed their specification, in 1880, more than 1,400 were in use, and many thousands were manufactured and sold during the four years they were pressing for a patent. In 1884, when the inventors sold the invention, those who bought seemed to have more ambitious views of the extent of the invention, and at once attempted to enlarge its scope by secur ing a patent on the use of two springs like those shown in the patent, but without a rocker box, and at a considerable distance apart on platform rockers. It may be conceded for the purpose of the argument that it was within the right of the inventors, pending the consideration of their specification, to enlarge their original claims to cover every improvement lurking in their invention, even though, when they first filed their specifications and claims, they may not have realized the wider application of their discovery. But it is manifest from the file wrapper that the patent-office examiners charged with the duty of limiting claims to what was really invented either did not think that this might be done, or else considered that the actual invention was limited to the exact form of device shown in the original drawings. In any event, the examiner was of opinion that the invention could not cover the application of spiral springs to the platform rocking chair. Thus he expressly ruled, and fortified the ruling by a very full discussion of his reasons therefor. Not only did he express this opinion, but he expressly adjudicated the point; for, when the inventors applied for claims which in terms covered platform rocking chairs, he rejected