Appeal from the District Court of the United States for the Northern District of Illinois, Eastern Division; George E. Q. Johnson, Judge.
Before Alschuler, Evans, and Sparks, Circuit Judges.
This is a patent infringement suit which was instituted by appellee. The bill charges appellant with infringement of United States Letters Patent No. 1,442,601, issued to Budd and Ibach, January 16, 1923. Appellant pleaded invalidity and non-infringement, and the court found the patent valid and infringed.
The patent relates to the metal working art, and covers a process for making tapered disks, a machine therefor, and a process for placing a flange thereon. The claims in suit are 2 and 6 which are machine claims,*fn1 and 14, 17, 19, 20, and 25 which relate to process.*fn2
From patentees' application we gather the followings facts: One of the chief objects of the invention was to provide a machine by which tapered steel disks might be formed from a square blank of uniform thickness, with a minimum amount of waste and at a low cost. In general the invention consists in rolling rectangular metal blanks of substantial uniform thickness into disks such as are used in the manufacture of disk wheels, tapered outwardly from the center and having a substantially circular periphery, by rolling the metal blank along a plurality of different radii from the center outwardly so as to force the excess metal radially of the blank toward the periphery. This tapers the blank and also causes the periphery to approach a circle. The invention also comprises a machine for carrying out the method, including a pair of operating rolls which act upon the metal blank. One of those rolls has a substantially triangular working surface of cam formation, so that points on that working surface are at progressively greater distances from the axis of the roll.
The drawings accompanying the application illustrate a machine comprising upright frame members in which two rolls, one above the other, are journaled, said rolls being driven in opposite directions from a suitable source of power. A table extends forward from the frame, and is provided with ways on which the carriage is slidably mounted. An arm is pivoted at its forward end between the lugs on the carriage by means of a bolt. A pin projects downward from the rear end of the arm and is adapted to extend through a central opening formed in the metal blank. This arm and pin serve as a means for centering the metal blank with reference to the carriage and rolls. A cross bar extends between the uprights at the forward part of the machine, and a stop screw is threaded through the cross bar so that its forward end extends into a position to be engaged by the carriage and serves as an adjustable stop to limit the movement of the carriage toward the rolls.
The following figure correctly represents the rolls in patentees' machine:
A further description of their machine is as follows: A substantially triangular raised portion is formed on roll 4 and the height of the triangle is proportionate to the length of the square or rectangular metal blank upon which the work is to be performed. The narrow shoulder 19, to which we shall refer as the apex, is disposed midway between the ends of the roll, and the base of the triangle extends from one edge of the roll to the other. The surface of portion 18 is at all points equidistant from the axis of roll 4. A substantially triangular portion is formed on roll 3, and so positioned as to co-operate with 18 on roll 4. This portion extends from shoulder 21, which co-operates with shoulder 19 on roll 4. A notch 22 is formed centrally in 21 so as to accommodate the centering pin. At the apex of this triangular portion there is portion 23, all parts of which are equally distant from the axis of the roll 3. This portion is defined by the shoulder 21, the edges of the raised portion, the arc of a circle concentric with notch 22, and covering substantially ninety degrees, and lines drawn from the ends of said arc rearwardly to the edges of the raised portion, thus forming the horns 25 which are in the same cylindrical sufrace with portion 23. From the line 26 forming the inner boundary of portion 23, the cam surface 18' extends rearwardly to the base of the triangle, increasing in its distance from the axis of roll 3 continuously from line 26 to the base of the triangle. At the edges of the cam surface 18 there are formed the beveled surfaces 27 which are widest adjacent to shoulder 24, and grow narrower as they approach the parts 25 and the line 26.
Patentees describe the working of the machine substantially as follows: The square metal blank is heated and mounted on the carriage and is centered by means of the arm and pin hereinbefore referred to. While the rolls are in such position that the working surfaces are on opposite sides of the rolls from each other the carriage is moved inwardly until it engages the threaded stop screw, thus carrying one-half of the metal blank between the rolls. As they revolve in opposite directions the surfaces 18 and 18' move toward each other until the shoulders 19 and 21 are in line with each other and the notch 22 receives the centering pin. At this position of the rolls the central part of the blank is gripped firmly between the surface 18 of roll 4 and the part 23 of roll 3. The distance between these parts is such that there is no compression of the blank at this point. By this means the blank is firmly held at the beginning of the operation. As the rolls continue to revolve, the central part of the blank is given a continuous support by the corresponding surface 18 on roll 4. As the distance of the surface 18*fn1 from the axis of roll 3 increases continuously from line 26 to the base of the triangle, the pressure of the rolls increases continuously and the distance between the working surfaces on the rolls decreases continuously with the result that the metal of the blank is pressed and squeezed out giving the metal the tapered cross section, and elongating it somewhat. The fact that the parts 25 are in the same cylindrical surface as 23 prevents buckling or curling of the sheet during the rolling operation, as they tend to grip the blank on both sides of the point where the compression is taking place. The beveled edges 27 are provided in order to reduce the compression adjacent to the edges of the surface acted upon so as to eliminate the pronounced ridges which would otherwise be caused at those points, and prevent any material disturbance to the adjoining segments.
The machine described in patentees' application contemplates the rolling of the metal blank into an approximate circle with four passes through the rolls, that is to say the base of the triangular cam is the same length as one side of the metal blank, and the arc caused by each pass is ninety degrees. After the first pass through the rolls, the second pass is made 180 degrees from the first, or on the side opposite the first, and the third and fourth passes are made laterally to the first and second. Patentees state that the blank may then be trimmed and finished without further rolling, but that they find it desirable in many cases to give it four more passes along the radial lines in order to eliminate the ridges and cause the periphery of the blank more nearly to approach a circle. After the rolling operation is completed, the blank may be trimmed to bring its periphery to a true circle. The flange on the periphery is then pressed up from the body of the blank and a central opening punched in it thus forming the completed wheel disk. The flange and central opening, however, are not formed by the patented machine, but they are included in the process covered by the patent.
It is further stated by patentees in their application and specifications that, by the use of the machine and method, a wheel disk of tapered cross section may be produced very efficiently and at low cost; that the disk is formed by a simple rolling operation which can be quickly performed, and that there is practically no waste, as the square blank is little metal to be trimmed off.
Appellant's machine and process which are alleged to infringe, roll disks radially from the center and tapered on both sides, from equilateral octagonal blanks. Its method of cutting these blanks from strip stock involves an initial waste of material in excess of twenty per cent which is much in excess of the loss involved in appellee's method. Appellant's machine is provided with automatic indexing and feeding means which move the blank on 45 degrees after each pass, and eight passes are made in regular succession. These, however, are not closely confined to the octagonal sections. Two rounds of rolling are necessary in appellant's process. On the second round the indexing table is automatically set ahead 22 1/2 degrees, after which eight more rolling passes, again indexed at 45 degrees, are made in regular succession midway between the passes of the first round. The cam die which is used on the rolls is kidney shaped and has a double curvature contour. The working surface is ground to a double curvature, the central portion being cylindrically ground, and the end portions being ground tangent to the cylindrical portions, and relieved slightly toward the ends of the die. The working surfaces of these dies seem to us roughly to approximate a triangle, but not exactly comparable in size to the octagonal sector. The ends of the dies receding in height from the working surfaces constitute bevels on the dies of the machine, but they are not the same shape nor nearly so marked as patentees' bevels. Appellee's exhibit of appellant's device as applied to the octagon discloses that the beveled portions of appellant's device extend into each adjoining sector a distance of about one-third of the periphery of the sector. Indeed this exhibit discloses that a substantial portion of the working surface ...