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A request was recently received from one of our readers for information regarding a cow milker pat ented March 25, 1865. Our correspondent desired, if possible, to have one of these machines repaired. The fact that a cow milker of such remote date could sur vive to this day and still be considered of practical value interested us. Although we failed to trace the present address of the manufacturers, we discovered that the design of the machine involved a very novel principle in pump mechanism. A photograph of our correspondent's cow milker is shown herewith, and the accompanying drawings are copied from the original patent granted to L. O. Colvin, of Philadelphia, Pa. One of the illustrations is a cross-sectional view, and the other shows the under side of the milker. The machine consists of an approximately rectangu lar chamber A. formed at each corner with an inverted cup B. Communicating with each cup is a teat tube C, formed of rubber, in which a spring is imbedded. Fitted into each cup B is a cup-shapEd valve D. The lower rim of each valve D is formed with a flange d, which rests upon a flange b formed on the cup 3. The valves D are fastened to rods E, and these rods are engaged by the arm of a spider F pivoted at G to the under side of the chamber A. Each cup B is formed with a port J, which leads into the main chamber, and between the cups B and their respective tubes C are clap valves H. To operate this cow milker the spider F is oscillated on the pivot G as a center, which serves to tilt the rods E to the position shown by the dotted lines. As the valve cups D are flexible, they wabble with the shafts E. and produce an alternate exhaust and compression in the cups B. In applying this cow milker, the tubes C are fitted over the teats, and then the operation of the spider F serves first to draw the milk into the cups B, and then, when the clap valves H close on the return stroke, to force the milk through the ports J into the chamber A, whence it flows out through the tube K into the de sired receptacle. The particular advantage claimed for this cow milker by the inventor is that the four pumps while operating simultaneously act independently of each other, so that each teat may be milked completely dry. The inventor states that in cow milkers previously made a single pump was provided to draw the milk from the four teats of the cow; and when one or more of the teats became dry before the others, their shrunken condition permitted air to enter the pump, rendering the latter inoperative, and precluding the milk being extracted from the other teats. For this reason he used four separate pumps, so that when air was admitted into one of the tubes, it would not affect the action of the other pumps.
