Opinion ID: 298437
Heading Depth: 1
Heading Rank: 1

Heading: the patents in issue

Text: 7 We turn initially to the patent infringement claims. The structures involved in the instant case are animal traps intended for fur trapping, particularly muskrats, beaver, marten, and other fur-bearing animals. The Conibear structure is a killer type trap, a steel trap which kills the entrapped animals through suffocation or by breaking the animal's neck. The Lehn device presents a trap similar in operation and configuration, except for a modification of the trigger element. These traps, referred to as swing frame traps, reflect a structure consisting of a pair of substantially identical rectangular frames, with one of the frames being slightly smaller and capable of rotating within the other frame. The two rectangular frames are hinged together or pivoted at a midpoint at their ends, with the sides of the frames comprising the jaws of the traps. When hinged and placed in a vertical position, the top and bottom sides of the two rectangular frames may be placed in a position parallel with each other. The jaws of the traps are held against the tension of a coil spring or springs in an open or set position by a sliding latch mechanism made of interconnecting wires constituting the trigger of the traps. 8 The Conibear trap is released by a wire extending into the center of the trap which disengages the latch member from one of the rectangular frames when the trigger arm which is directly attached to the latch becomes actuated by an animal entering the trap. The latch mechanism contains a diamond shaped wire element which pivots in any direction upon movement transmitted to it by the trigger arm; this movement affords a positive and quick release of the trap. Upon release, the jaws swing rapidly in opposite directions in egg beater fashion under the influence of a powerful coil spring to catch the animal. The following photograph 3 demonstrates the Conibear trap in a set position. 9 NOTE: OPINION CONTAINING TABLE OR OTHER DATA THAT IS NOT VIEWABLE The Lehn patent, except for some minor modifications in the construction of the pivotal aspects of the frames, reflects an improvement over the Conibear patent, specifically in the trigger mechanism. In the Lehn trap, the latch consists of a key-like mechanism with a collar at one end and U-notches at the other end. The collar encircles the frame side or jaw of the trap; it freely slides and rotates thereon. The opposite end of the latch grasps the second jaw by one of the U-shaped notches fitting on a partially cut-down sleeve which also freely slides and rotates upon the second frame side or jaw. A trigger arm extends from this cut-down sleeve into the trap. Movement against the trigger arm rotates this sleeve, positively forcing the U-notched latch out of engagement with the second jaw. In this way, the mechanism affords instantaneous release action. The following photograph shows a Lehn trap as set. 10 NOTE: OPINION CONTAINING TABLE OR OTHER DATA THAT IS NOT VIEWABLE 11 The defendants' alleged infringing traps, known as the Hudson Bay Killer Traps, are almost identical in appearance and construction to the Lehn traps, except for a modification of the trigger arm and sleeve attachment to the second frame side or jaw of the trap. Like Lehn, a U-notched latch is rotatable and slideable on the first jaw. This latch engages the second jaw not directly upon a sleeve which is attached to the second jaw, but indirectly through a hinged second sleeve connecting to the trigger arm. This second sleeve contains a cut-down opening similar to that on the Lehn trap; it permits the notched latch mechanism to hold the two jaws in a set position. Movement against the trigger arm causes rotation and lifting of the notched latch which, in turn, produce instantaneous release action as in the Lehn device. The following photograph illustrates the slight differences between the allegedly infringing trap and Lehn. NOTE: OPINION CONTAINING TABLE OR OTHER DATA THAT IS NOT VIEWABLE 12 The evidence introduced by the plaintiff establishes that the Conibear and Lehn type of swing frame trap constituted a substantial improvement over the old leg-hold trap previously used by trappers. The leg-hold trap has been the mainstay of the fur-trapping industry since first introduced in England in the Seventeenth Century. The leg-hold trap came into its modern form with the invention of the steel trap in the Nineteenth Century. The leg-hold trap, as its name implies, utilizes spring-loaded steel jaws which clamp around the leg of the animal when the animal steps into or releases the trap. These traps are deficient in several respects. They cause considerable pain and suffering for the trapped animal since the traps fail to kill the animal. They often work inefficiently because many trapped animals are able to work loose and escape. Many animals, particularly muskrats, escape by breaking the leg and then chewing it off. The leg-hold trap poses substantial danger to the trapper and, in some instances, its use reduces the quality of the animal's fur. On the other hand, the swing frame killer trap may be set faster, easier, and safer. Moreover, animals may be removed from it more quickly than from the conventional trap. One of the most significant advantages of the swing frame trap is its humane nature since in most cases it immediately kills the animal. 13 Despite evidence of the substantial advantages of the swing frame traps over the conventional leg-hold traps, the district court held, as to the Conibear and Lehn patents, that 14 Notwithstanding the greater utility, humaneness and commercial success of the Conibear type trap, factors certainly entitled to consideration when determining patentability, it appears to the Court that the features which characterize the Conibear and Lehn traps over the prior art are such as would be obvious to a mechanic skilled in the trap field at the time of the patenting of the Conibear and Lehn traps. [312 F.Supp. at 371-372].