Hayes Spray Gun Co. v. E. C. Brown Co.

The district court had jurisdiction over these patent and other claims arising under the United States patent laws (35 U.S.C.) ( 28 U.S.C. § 1338 .) This court’s jurisdiction over the appeals is conferred by 28 U.S.C. § 1291 .

The controversy concerns a spraygun used for applying insecticides, fertilizers and other chemicals to plants. Spraying devices such as the flit gun and tank sprayer, in use for many years, are desirable because they produce a spray of uniform strength. The difficulty with all such sprayers is that they are operated by hand pumps and therefore require a great deal of effort to use. Inventors searched for many years to develop a gun that would be easy to use. One solution was to eliminate manual operation by using the pressure in hydrants connected to the domestic water supply: sprayers were designed to fit on taps or garden hoses so that the stream of water could provide the power that was needed to operate the gun and produce the spray. This procedure eliminated the effort required to operate the hand pumped machines, but it did not achieve the uniformity of operation which the hand machines had attained. Because of variations in water pressure, the…