Dundon

[1] This is a bill to enjoin the infringement of a patent, No. 653,503, issued to plaintiff on July 10, 1900, covering “doors for digesters” — a steam-tight door for use on retorts in canneries and other establishments >vhere the processing of the product is by cooking with steam, the successful operation of which requires the introduction of steam of considerable pressure. To meet the requirements of the process the door of the retort is required to be large enough to enable the cans or other containers to be readily and quickly placed in and removed from the retort. It must be heavy to withstand the pressure of the steam, be capable of being opened and closed quickly, and to work efficiently it must be made absolutely steam-tight. The device of the patent is designed to meet these necessities, and, briefly described, is constructed substantially as follows:

The door is not itself hinged to its frame, but is swung on two bars, called “pressure bars,” which pass horizontally through housings secured to its outer surface or face, and these bars form the hinges for the door, being hinged at one end to the door frame in such manner that when the door is swung to it closes squarely…