Patent GB-189708846-A (GB)
Title: Improvements in Milking Apparatus.
Inventor: LAWRENCE WILLIAM HENRY
Filed: 1897-04-07
Granted: 1898-03-05
Abstract: 8846. Lawrence, W. H., and Kennedy, R. April 7. Cow - milkers.-Relates to detail improvements in connection with cow-milking appliances such as are described in Specifications Nos. 6129 and 14,619, A.D. 1896. Two vacuum reservoirs are employed, in one of which the vacuum is maintained at the desired maximum suction, and in the other the vacuum is maintained at the desired minimum suction, and pipes connected with the reservoirs are laid on in the milking- shed, and branches from these pipes are connected to "pulsators" as described in the above-mentioned Specifications. The pulsators act to place the tube from the teat cups alternately in communication with the pipes from the two vacuum reservoirs. The pulsator comprises a cylinder having a reciprocating piston operated by the vacuum pressures in the two pipes. The valve through which the vacuum pressure is supplied for actuating the piston is operated by an arrangement of spring and levers so as to give a sharp throw-over action to the valve to ensure its proper action. The piston is provided with a valve recess which reciprocates over three ports. The two outside ports are connected respectively to the pipes from the maximum and the minimum suction reservoirs, and the middle port Q<2>, Fig. 4, is in communication with a tube R' which reaches to the bottom of a glass receptacle R<2> connected by an airtight joint with a chamber R surrounding the pipe R' and placed in connection with the teat cups by suitable pipes. The pipe R<1> is perforated and surrounded by a piece of rubber tubing near its upper end to form a valve. This arrangement allows air to pass to the teat cups, to reduce the suction, without having to force its way through the milk flowing into the milk receptacle. The maximum and minimum vacuum reservoirs are provided with pipes of suitable lengths dipping into a tank of water. The maximum reservoir is connected to a vacuumproducing apparatus such as a steam ejector. Both reservoirs are fitted with floats which, when the requisite decree of exhaustion is exceeded, are lifted by the rising water; in the case of the maximum suction reservoir, the float operates a valve to shut off the supply of steam to the ejector, and, in that of the minimum suction reservoir, the float opens an air inlet and thus tends to maintain the requisite degree of suction in each reservoir. The minimum suction pipe is placed in communication with the maximum suction pipe by means of a loaded valve, which acts to prevent the suction in the minimum suction reservoir becoming too small. The Specification describes a special form of valve for controlling the steam supply to the steam ejector, special forms of loaded valves to be used with the minimum suction reservoir instead of the columns of water described above, a form of bye-pass or relief valve to be used when a pump is employed for obtaining vacuum, and valves to be used in connection with the maximum and minimum. suction pipes to the pulsator. Fig. 14 shows an arrangement of cisterns for obtaining a vacuum by the discharge of water from a closed reservoir. Two cisterns A', A<2> are arranged side by side, and are provided with a sliding valve C<1> arranged to place one of the cisterns in communication with the water supply pipe E, while the other cistern is in communication with the discharge pipe D. The valve C' is operated automaticallv by the following arrangement :-The valve C<1> is connected by a link B<4> to a pivoted arm B<3> connected by a spring B<2> to one arm of a bellcrank lever carrying the float B. The parts are so arranged that the valve C<1> has a sharp throw-over movement imparted to it. The cisterns are connected by suitable valves to the maximum suction pipe F.