The opinion of the court was delivered by: GALSTON
This is a patent suit involving the alleged contributory infringement of letters patent No. 1,582,219, issued April 27, 1926, on the application of Hopkinson and Dewey for a seal for cans and other containers; and direct infringement of patent No. 1,765,134, issued June 17, 1930, on the application of Dewey and Crocker for a sealing composition.
The specification of the former patent recites that the invention relates to seals for the joints between the bodies and covers of containers from which air is to be excluded and in which liquid or some liquid contents are to be confined. It is especially intended for use in open top metal cans in which no solder is employed but in which the head is secured to the body by "double seaming". The double seaming is effected by rolling or spinning together the edge of the can cover and a small flange which has been previously pressed out from the bottom of the can into a double seam. The sealing is brought about by the compressive confinement, between the surfaces of the container body and the cover, of a material consisting of a rubber base, deposited directly from a water-emulsion of rubber.
Reference is then made to sealing devices of the prior art which include rubber gaskets, paper gaskets or backings, and rubber cement solutions. Rubber gaskets are stated to be expensive and difficult to apply and are subject to deterioration; paper gaskets are said to require special machinery and entail difficulty of application. Rubber cements, having a viscosity greater than that contained in a half pound of rubber per gallon of solvent, were believed by the inventors to give difficulties in manipulation in the ordinary machines.
Accordingly, the invention of the patent seeks to utilize rubber to secure the advantageous properties "inherent in ample volume of elastic material, permanent retention of elasticity, compressibility and unbroken continuity, and substantial immunity to deterioration by exposure to air, heat and light."
The specification recites: "The invention * * * is characterized in its broader aspect by the use of a water-emulsion of rubber exemplified by that which also occurs naturally as rubber latex, as the material from which to produce by deposit a sealing composition."
In operation the latex emulsion is introduced into a machine and applied through a nozzle to the part to be sealed. The emulsion thus deposited is then dried. When a natural latex is employed the evaporation of the liquid and drying of the deposit is stated to involve a primary coagulation of the particles of liquid rubber with no appreciable injury "to the protective colloid which is deposited in association with the rubber."
The patentees state that the latex employed may be obtained from the rubber tree, and where it is to be conveyed for a distance a percentage of ammonia is preferably added for preservative purposes. It is also specified that with latex various fillers, such as carbon black, zinc oxide, ground cork, coloring materials including dye-stuffs and pigments, may be combined. Comparing the advantage of the latex with the prior art, the patentees observe that it contains approximately 2.75 pounds per gallon of solid constituents as against one-half pound of rubber to one gallon of solvent in the case of cements.
All of the claims of the patent are in issue. The defendant denies infringement and alleges invalidity and laches.
It will suffice to discuss Claim 1 as typical. The claim reads: "A container closure provided with a sealing material deposited thereon comprising as its basis rubber characterized by substantial conservation after drying of the integrity of rubber particles dispersed in water-emulsion."
The language of the claim which described the material as one "comprising as its basis rubber, characterized by substantial conservation after drying of the integrity of rubber particles dispersed in the water-emulsion" amounts to no more than a statement of the inherent qualities or properties of latex. One of the questions presented, therefore, is whether there was any invention in adapting the substance "latex", theretofore known in the rubber art, to the new use or combination described in the patent.
British patent No. 1801 of 1791 to Peal includes a reference to caoutchouc and its applicability to leathers and cloths and other articles intended to be rendered water proof. Dr. Hauser, plaintiff's expert, who I may say proved a most interesting witness both for his unusual attainments in the field and his directness in response to questions, admitted that one Fourcroy, also as early as 1791, suggested a direct use of latex. Dr. Hauser conceded also that latex could be preserved by the addition of an alkali.
British patent No. 5122 of 1825 to Hancock for the purpose of preserving various textile and other articles from injury from air or moisture refers to the use of the juice obtained from certain hevaea trees which grow in several parts of South America, the East Indies, and other places abroad. The inventor says: "I find that the said juice or liquid, when exposed to the open air in the sun, or in a warm room, becomes inspissated or dried and then forms a substance exactly resembling * * * and well known by the names of caoutchouc or India rubber or elastic gum. In colour and consistence the said juice very much resembles cream."
British Patent No. 467 of 1853 to Johnson gives the specific instruction for purposes of preservation during transportation found in the patent in suit. The patent recites: "Shortly after the milk or juice is collected it is strained, and has then added to it a quantity of the concentrated liquor ammonia * * *." The following passage is also of significance: "For the protection of a new and useful article of manufacture from this substance, it is poured or run onto plates of glass or polished metal or other suitable receiving surface * * *. In this condition it is subjected to slow atmospheric evaporation, either in the open air or at the ordinary atmospheric temperature * * *. By this treatment the liquid portion of the spread-out mass is dissipated, leaving behind it a solid mass, very elastic and tough * * * and possessing properties distinct from all other known substances."
It is important to note that Dr. Hauser admitted that such films as Johnson obtained did not differ in any respect from the films that are obtained by Hopkinson and Dewey.
British patent No. 7694 of 1905 to Morisse adds nothing to what has been said and is merely cumulative with respect to the use of alkali in combination with latex. He says: "* * * it is of great interest to be able to transport the lactiferous juices in a liquid ...