Leach v. Rockwood & Co.

• Decision Date: 10 July 1968
• Docket Number: No. 16517.,16517.
• Citation: 404 F.2d 652
• Parties: Elbert C. LEACH, Plaintiff-Appellant, v. ROCKWOOD & CO., Defendant-Appellee.
• Court: U.S. Court of Appeals — Seventh Circuit

404 F.2d 652 (1968)

Elbert C. LEACH, Plaintiff-Appellant, v. ROCKWOOD & CO., Defendant-Appellee.

No. 16517.

United States Court of Appeals Seventh Circuit.

July 10, 1968.

Joseph G. Werner, Madison, Wis., Arthur H. Seidel, Allan W. Leiser, Milwaukee, Wis., for appellant.

Joseph P. House, Jr., Henry C. Fuller, Jr., Walter S. Davis, Milwaukee, Wis., for appellee.

Before HASTINGS, FAIRCHILD and CUMMINGS, Circuit Judges.

HASTINGS, Circuit Judge.

Elbert Leach appeals from an adverse judgment entered June 29, 1967, following a bench trial, in his patent infringement action against appellee Rockwood & Co. The trial court held the patent in suit invalid and not infringed.

The patent in suit, Patent No. 2,580,306, was issued to appellant and others December 25, 1951 and covers an automatic silo unloader. Nine of the patent claims were involved in the suit and all were held invalid and not infringed. Leach v. Rockwood & Company, D.C.W.D. Wis., 273 F.Supp. 779 (1967). Since the trial of this case we have considered eight of these claims in a companion case and held them invalid. Leach v. Badger Northland, Inc., 7 Cir., 385 F.2d 193 (1967). Appellant does not press his appeal as to those eight claims.

The sole claim in issue is Claim 8, which covers:

"A silo unloader, for installation in a silo above the surface of the silage, comprising a vertically movable spiderlike frame having a center portion and three horizontally radiating arms, which arms are adapted to engage with the sides of the silo to center the frame within the silo, three suspension cables connected to the arms, which cables are adapted to extend vertically over pulleys mounted above the same in the top of the silo and to be connected together beyond the pulleys whereby to support the frame against substantial tilting and provide in effect a single raising and lowering cable for the frame operable from a point outside the silo, said cables also acting to support the weight of the frame and to restrain the frame against rotation while allowing the frame to turn a part of a revolution, an arm journalled on a vertical axis in the center portion of the frame and extending horizontally beneath the frame for rotation in a horizontal plane, means associated with said last mentioned arm for loosening the silage and moving the loosened silage inwardly toward the center portion of the frame, means mounted on the frame for rotating said arm, and means also mounted on the frame for conducting the loosened silage to a point outside the silo, said conducting means including a portion which extends laterally between two of the suspension cables and is pivoted for horizontal movement relative to the frame."

The alleged infringing device is appellee's Volumatic silo unloader, which appellee's predecessor in interest began producing in 1957. The cutting means of the Volumatic is an auger mounted under and aligned with a horizontal cutter arm. The cutter arm measures approximately three-quarters the diameter of the silo in which the unloader is installed, and the auger measures slightly longer than the radius of the silo. The outer ends of the arm and the auger are in close proximity to the silo wall. At the inner end of the auger, slightly past the center of the silo, a fan casing intersects the cutter arm. A motor is mounted on the cutter arm beyond the casing. At the outer end of the cutter arm two rubber wheels engage the silo wall, and at the arm's inner end a spring-loaded arm extends to the opposite silo wall. Another arm, attached to the cutter arm near the fan casing, extends laterally at an angle of ninety degrees to the silo wall. Rubber wheels are mounted at the ends of both extension arms.

The fan casing on the Volumatic opens upwardly into a short duct which is journaled on a frame. The frame consists of three radially-extending beams joined together to form a small equilateral triangle at the center of the frame. Mounted on struts below the frame is a large circular track of a diameter a few feet less than that of the silo. Perforations in the track mesh with the teeth on a gear mounted horizontally on top of the cutter arm near its outer end. The gear is attached by means of a drive shaft to the motor on the cutter arm.

A discharge duct is journaled above the frame and aligned with the short duct atop the fan casing. It curves upwardly and laterally and extends slightly beyond the wall of the silo.

Cables are attached to the ends of the three arms of the frame and extend up to individual pulleys affixed to the silo wall near the top of the silo. The pulleys form the vertices of an imaginary equilateral triangle. The three cables are joined together beyond the pulleys and extend down to a winch installed at ground level outside the silo.

In operation the Volumatic is lowered in the silo by means of the cables and winch until the auger rests on the silage bed. The motor on the cutter arm powers the gear mounted near the outer end of the arm. The gear engages the perforations in the circular track attached below the frame and moves the cutter arm around the track.

As the cutter arm moves around the track across the silage bed, the auger, powered by the motor, loosens the silage and moves it toward the fan casing. The silage is forced into the fan casing through a rectangular opening. The fan, mounted vertically and powered by the motor, pneumatically and mechanically picks up the silage and propels it upwardly through the duct and discharge duct, which protrudes through the vertical opening in the side of the silo.¹ The silage falls to a receptacle on the ground.

The axis on which the auger of the Volumatic rotates is the axis of the silo. The outer end of the auger is held close to the wall of the silo by the spring-loaded extension arm at the opposite end of the cutter arm and by the reverse thrust of the auger itself. The two rubber wheels at the outer end of the cutter arm ride along the silo wall and keep the auger from striking it. The lateral extension arm mounted perpendicular to the cutter arm also engages the silo wall and prevents the unloader from swaying.

The ducts which convey the silage from the fan to the outside of the silo pass through the center portion of the frame and connect with the opening in the top of the fan casing. Since the fan casing is off-center relative to the center of the silo, the frame is off-center and its diameter is less than the diameter of the silo. When the unloader is operating, the frame swings in an orbit within the silo. Its ends do not engage the side of the silo.

VALIDITY

The essence of Claim 8 in suit is a three-point suspension system utilizing a three-armed frame suspended from cables, which system keeps the unloader level and restrains the frame from rotation, while allowing a limited amount of reverse rotation to overcome resistance to the cutting means. According to the claim and appellant's argument, when the cutting means encounter resistance from frozen or compacted silage the torque produced by the driving means will rotate the frame counter to the normal rotation of the cutter arm. This rotation will twist the cables, lifting the unloader up and away from the silage bed. The weight of the unloader will cause the cables to straighten, dropping the unloader onto the silage bed, and this momentum will overcome the resistance to forward movement of the cutter arm.

The trial court concluded that the patent in suit did not satisfy the statutory requirement of nonobviousness. 35 U.S.C.A. § 103. The court then stated:

"The conclusion that the patent in suit does not satisfy the nonobviousness requirement of 35 U.S.C. § 103 applies to all the claims involved in this action. As to claim 8, it appears that the most pertinent prior art was cited to the patent examiner, and as to that claim a presumption of patentability applies. However, this court concludes that the Burgess patent contains all the essential elements of claim 8 and therefore claim 8 should not have been allowed." 273 F.Supp. at 791.

We interpret the court's language as a finding that Claim 8 is invalid both for obviousness and for anticipation by Burgess Patent No. 1,233,308. Before this court appellee has all but conceded appellant's argument that the trial court erred in finding anticipation by Burgess.

We agree with appellant. Burgess discloses a silo unloader suspended by a single cable and restrained against rotation by a bucket elevator affixed to the frame and extended through the vertical opening in the silo. The trial court apparently mistook four struts rigidly attached to the frame for a four-point suspension system. Burgess clearly...