Williams Iron Works Co. v. Hughes Tool Co. (109 F.2d 500, 1940)

PHILLIPS, Circuit Judge.

Hughes Tool Company brought this suit against Williams Iron Works Company for alleged infringment of five patents. From a judgment holding the patents valid and infringed, Williams Company has appealed.

Each of the patents relates to rotary bits used in well drilling. In rotary drilling a bit is mounted at the lower end of the drill stem. The bit comprises a plurality of frusto-conical shaped cutters which, when the drill stem and bit are rotated, cut and disintegrate the formation being drilled. The cuttings are continuously washed from the hole being drilled by mud which is circulated down through the drill stem and out through openings in the bit in the well hole, where the mud picks up the cuttings and returns to the surface along the outside of the drill stem. Each of the patents covers a combination of elements constituting a drill bit. Three relate to the cutting surface of the cutters and two relate to the shaft upon which the cutters are mounted and the bearings upon which the cutters travel and which hold them on the shaft.

I.

Scott Patent No. 1,480,014.

This patent was issued January 8, 1924, on an application filed January 16, 1922. It covers self-cleaning roller cutters for rotary drills. Scott first designed cutters of individual and cooperative characteristics. Theretofore the several cutters used on a rotary drill were identical, they did not cooperate with each other, and each had to be smaller than one-half the diameter of the hole to provide clearance for the teeth on each to pass the teeth on the others. The objects of the invention are to provide a plurality of cutters so shaped and mounted as to cooperate to clear each other of material which would otherwise tend to adhere thereto and clog the cutting action of the bit, and constructed so as to be larger and stronger than non-cooperating cutters. The embodiment of the invention illustrated in the patent drawings employs two cutters, although the patent is not limited in this respect, and the more common practice today is to employ three cutters. The device consists of a head with a threaded upper shank to screw into the drill stem. The lower end of the head is provided with a transverse V-shaped slot, on the opposite flat sides of which bearing members are mounted. On each of the bearing members is mounted a cutter which is approximately frusto-conical in shape. The two cutters when mounted upon the head have their adjacent sides lying practically within the central longitudinal axis of the drill. The teeth are positioned upon each cutter cir-cumferentially thereof in rows along its tapered surface. The teeth upon one cutter are positioned in rows at slightly different distances from the base of the cutter than are those upon the other. The rows of teeth upon one cutter are slightly offset from the rows of teeth upon the adjacent cutter so that the rows of teeth on each cutter inter-fit with the rows of teeth on the other cutter. The rows of teeth are cut with grooves extending longitudinally from the base to the apex of the cutter to provide cutting edges adapted to cut and disintegrate the formation in the bottom of the hole.

The head of the drill is ordinarily rotated by means of a drill stem in a clockwise direction. The cutters roll upon the bottom of the well. The cutters revolve clockwise, but at the point between the two cutters where the teeth on one pass the teeth on the other, the teeth are traveling in opposite directions. Unless means are provided to prevent it, in drilling certain formations, material will adhere to the surface of the teeth and clog the cutting action of the cutter. In the device of the patent in suit the interfitting teeth cooperate to free and dislodge adhering material. This action keeps the cutters clear at all times and avoids, to a substantial degree, the difficulties usually experienced with roller cutters in sticky formations. The size of the bit being limited by the size of the hole, it is desirable to utilize all available space. Since the cutters cooperate and the teeth interfit, each cutter may be larger than one-half the diameter of the hole. This makes possible the use of substantially larger and) stronger cutters.

Claims 1 to 4 are in suit. Claim 1 is illustrative and reads as follows:

“In the roller earth-boring drill the combination of a head, two opposite, approximately frusto-conical shaped cutting rollers mounted on the forward end thereof and circumferential rows of teeth of approximately equal size formed on e.ach cutter, the teeth on one cutter being adapted to interfit between those of the other for the purpose described.”

These claims were held valid by this court in Southwestern Tool Col v. Hughes Tool Co., 10 Cir., 98 F.2d 42. The Williams Company does not challenge the validity of the patent, but denies infringement.

The Williams Company manufactured its first bits in June, 1935. Mr. Gruner, who designed the alleged infringing bit for the Williams Company, admitted that on some of the first bits manufactured the teeth on each cutter extended past the point of the teeth on the other cutters to the extent of approximately one-sixteenth of an inch, resulting in some interfitting of the teeth. He testified that this interfitting was accidental and unintentional and resulted from failure to make sufficient allowance for distortion of the metal in welding the cutter shaft on to the head. He stated that in some instances the distortion at the time of the welding tended to throw the shafts inwardly, causing some interfitting of the teeth. He further testified that the first bits manufactured by the Williams. Company did not work efficiently and were returned and that the interfitting was eliminated by providing greater allowance for distortion in the welding operation.

The teeth on the Williams Company cutters are slightly offset relative to the teeth on the other cutters so that they may inter-fit, and there was interfitting of the cutter teeth in a substantial number of the earlier bits manufactured by the Williams Company. One of these bits, introduced in evidence as Hughes Company Exhibit 6, has interfitting teeth. It was found by a field representative of the Hughes Company in the Jesse Oil Field near Ada, Oklahoma, in December, 1936. This representative also observed at the same place eight other of these bits with interfitting teeth like Exhibit 6. And one Mobley saw about fifteen bits of the Williams Company, with inter-fitting teeth like Exhibit 6, in the Ada and Seminole oil fields in Oklahoma in the fall of 1936.

The Williams Company asserts that the interfitting of the teeth in the bits manufactured by it is not sufficient in degree to effect cleaning of the teeth, and that its bits are cleaned by the flushing fluid, effected by arranging the watercourses for the flushing fluid so it passes through the longitudinal grooves between the teeth and frees any material adhering to the teeth.

It seems to us that any substantial inter-fitting of the teeth would tend to dislodge material adhering thereto and aid in keeping the teeth clean.

In determining whether a device infringes, we look to the modes or means of operation, the functions, and the effects of the patented device and the accused device. If they are substantially identical, the principle of the patent is appropriated and infringement results. Otherwise stated, the test is whether the two devices do the same work in substantially the same way and accomplish substantially the same result.

Identity of function exists where the function is the same, although impaired in degree, and identity of result exists where the result is the same in kind, although lesser in degree. Impairment of function and lessening of result, in degree only, does not avoid infringement.

Here, the modes or means of operation and the functions of the two devices are substantially identical and the result accomplished by the alleged infringing device is .the same in kind and is attained in a substantial degree, although not as fully and perfectly, as by the patented device.

Counsel for the Williams Company assert that there is no evidence that Exhibit 6, or bits like it, found in the Jesse, Ada, and Seminole oil fields, were sold by the Williams Company or ever used. The bits were marked “The property of W. I. W.” Exhibit 6 shows that it has been worn through use and it is a fair inference that these bits were made and sold by the Williams Company for use in drilling.

We accordingly conclude that these bits infringe the claims in suit.

II.

Scott and Wellensiek Patent No. 1,647,753.

This patent was issued November 1, 1927, on an application filed April 15, 1926. It relates to roller cutters for rotary drills. It is particularly directed to the size, shape, and location of the teeth on the frusto-conical shaped cutters.

The objects of the invention are self-cleaning teeth, constant rolling motion of the cutters, and effective and speedy cutting and disintegration of the formation being drilled.

Claims 2, 3, 4, and 5 are in suit. The elements of claim 4, which is typical, are:

In a rotary well drill having cutters with their cutting areas converging toward the central axis of the drill and mounted to contact with the bottom of the hole with an approximately true roller motion, the combination of

1. Cutting teeth formed on the cutters in rows extending around the conical surface thereof,

2. The teeth on one cutter being offset relative to those on the adjacent cutter,

3. The opposite sides of each row of teeth

(a) being spaced apart to allow clearance, and

(b) being deeply cut to produce long, narrow, penetrating chisels,

4. The cutting edges of the teeth extending the full width thereof.

Claim 2 differs from claim 4 in that it provides for rows of teeth inclined toward the apex of the cutter so as to extend vertically downward when in contact with the bottom of the hole, having their adjacent sides parallel, and being adapted to interfit. Claim 3 differs from claim 4 in that it provides for rows of teeth on each cutter adapted to interfit with the teeth on the adjacent cutter. Claim 5 differs from claim 4 in that it provides for rows of teeth inclined toward the apex of the cutter so as to extend vertically downward when in contact with the bottom of the hole, and having their adjacent sides approximately parallel. Until the advent of this patent the teeth on the cutters were approximately pyramidal in shape.

The embodiment of the invention illustrated in the patent drawings and disclosed in the specification may be described thusly: It comprises an ordinary rotary drill head with a transverse V-shaped slot. Pins or shafts are mounted in such slot so that they incline downwardly and inwardly from the sides of the slot toward the central axis of the head. Frusto-conical shaped cutters are mounted on the shaft. The teeth are long, narrow, and chisel-shaped and have cutting edges extending the full width thereof. They are arranged in circumferential rows around the face of the cutter. The adjacent sides of the rows are approximately parallel. The rows of teeth are spaced apart to provide ample clearance, and the rows on each cutter are offset relative to the teeth on the adjacent cutter. The teeth extend from th.e body of the cutter in a direction approximately radial to the center of the cutter but are inclined laterally toward’ the apex of the cutter, so that as they engage the formation they point vertically downward toward the bottom of the hole.

These large, widely-spaced, long, chisel-shaped teeth so arranged on the cutters penetrate effectively, produce constant and tru