The opinion of the court was delivered by: GALSTON
This is a patent infringement suit in which infringement is alleged of letters patent granted to Willard N. Sawyer, May 31, 1932, No. 1,860,789, on an application filed January 12, 1927.
The patent relates to a wood heel grooving machine and is concerned with the making of wood heels of the Louis type, as distinguished from the Cuban heel. The latter is relatively simple. The former is more difficult to manufacture, is more highly contoured, and is concave transversely.
On the front the heel has what was referred to at the trial as a "shank lip," or at times just a "lip," which projects forward at the attaching face of the heel at the point where the heel is affixed to the shoe. With this type of heel it is necessary to have a long attaching face in order to give the heel sufficient bearing on the shoe to keep it from being turned or damaged. In fitting the heel to the shoe, the leather of the sole of the shoe is split at the heel end and the split flap is turned down. There is a metallic fastening of some kind, whether of screws or nails, projecting from the inside of the shoe into the wood heel.
In practice, the shank lip is curved circularly and merges with the shank of the shoe so that they come together. The split flap is secured down over the breast face of the heel. It is then trimned off to fit the breast and to form the breast covering of the finished shoe.
A cross-section of the shank of the shoe at the place where the lip fits, if taken vertically and transversely, discloses a substantial circular arc; and the shank lip of the heel should have the curvature of the shank of the shoe in order to effect a proper fit.
The patent in suit refers to a prior invention of Harley W. Russ, patent No. 1,846,615, which describes a wood heel grooving machine; and Sawyer refers likewise to the art which preceded Russ. He says: "Prior to the invention of Harley W. Russ, described in his application Serial No. 587,893, filed Sept. 13, 1922, the surface formed by the grooving operation was merely such a cylindrical surface composed of an aggregate of horizontal straight lines, and included a straight horizontal lip portion where the heel merged into the shank of the shoe. This lip had to be rounded by hand in a second operation to bring it to the transverse curvature of the shank."
The Russ invention, while an improvement on the then understood prior art, did not avoid the necessity of the second operation referred to in the last sentence of the foregoing quoted paragraph.
In the manufacture of heels, the first operation is that known as "blocking," and involves sawing through the rough block. Four or five operations have to be performed on the block in forming the Louis heel: First, the sides and back are turned or rounded; next, a concave hollowed-out portion which rests against the sole of the shoe has to be shaped. The heel must be sawed to give the top lift surface and the heel seat surface the proper angle in relation to each other. In addition, the front, or breast of the heel must be grooved, that is, curved; and, finally there is the necessity, heretofore referred to, of shank lip scouring, that is, rounding the shank lip of the heel to fit the rounded instep of the shoe smoothly.
The plaintiff offered some evidence as to how the grooving operation was performed in the earlier art.
The first of these machines referred to was described as the push groover, and is shown in the Kinney patent No. 1,839,228. There were two objections to this groover: Frequently there was a sudden splintering of the block. This resulted from the cutting operation. In this machine a blade on each revolution cuts only part way across and not the full width of the block, and cuts substantially at right angles to the direction of the wood fibres, not diagonally across them. Each cut is a cut across all the fibers along the height of the breast face. This kind of cut is referred to as a "hard" cut. As the cutters leave the block at the following edge, while that portion of the cutter blade of the greatest diameter emerges before the rest of the blade, all that portion of the blade, except the widest part, comes out at once. To prevent the splintering of the block, it became necessary to use "backers" to support the fibers at the following edge.
Moreover, since the blade of this push groover cuts straight across the breast face of the block, the lip is left straight. This condition necessitated a rounding-off operation, so as to bring conformity to the curvature of the top face of the lip. This rounding-off operation was done by hand, the operator engaging the lip with a sandpaper-covered wheel.
The Russ machine effected an advance over the push groover, though it retained some of the characteristics thereof. As in the push groover, the cut is substantially of the shape of the profile of the edge of the cutter blade, and different sets of cutter blades in consequence had to be used for a particular style of heel. Also, the blade leaves the following edge in the same was as in the push groover, with a resultant tearing or splintering, and necessitated the use of backers. The operation of the Russ machine, however, rounded the lip and merged it with the breast with a single cutting operation.
The Sawyer machine avoids the splintering of the block heel, and the consequent use of "backers."
So far as the grooving operation is concerned, the following description of the machine will be sufficient: A rotating head carries the heel. The heel block rotates about an axis to carry the breast face of the block in a circular path through the surface of revolution of a whirling cutter designated 104. As in the Russ machine, there is a relative revolution between the cutter and the block about an axis. The result is a circular cut. The portion of the cutter which forms the lip will round the lip off, as shown at 105, Fig. 15. The degree of the curvature of the lip can be regulated by using different size blocks on which the heel blank is clamped, thus producing a different radius of curvature. At the same time the cutter head is adjusted on its slides to locate the cut at the right place in the heel breast.
The plaintiff stresses in the Sawyer machine, as an element of novelty, the angular relation between the cutter axis 103 and the shaft 32, the axis of relative revolution, around which the work revolves. It is obvious that the angle indicated is oblique. Sawyer stressed this as an important factor, for his specification recites: "I have found that the advantages of the invention referred to above can be retained, and additional advantages (including better work and increased production) secured, by placing the axis of rotation of the cutter at an oblique angle to the axis of relative revolution of the cutter and heel blank."
The result is that in the Sawyer machine, if the two axes do not actually intersect, the cutter axis will move relatively to the work axis in what is referred to by Mr. Packard as a hyperboloid of revolution. If, however, there is an intersection, then the cutter axis generates a perfect cone. The machine, however, functions precisely the same way, whether the cutter axis generates one way or the other.
Thus Sawyer, by his arrangement of parts, avoided the disadvantages of the Russ machine, and by securing what is described as the finest kind of cut, an increase in speed and smoothness, avoided the hard cut of the Russ machine; and also by reason of the angular relationship the cutter leaves the following edge so ...