Patent GB-388102-A (GB)
Title: Improvements in, or relating to, milking machine pulsators
IPC: A01J5/12
Filed: 1931-09-12
Abstract: 388,102. Cow-milkers. INTERNATIONAL HARVESTER CO. OF GREAT BRITAIN, Ltd., 259, City Road, London.-(International Harvester Co. ; 606, South Michigan Avenue, Chicago, U.S.A.) Sept. 12,1931, No. 25610. [Class 84.] A milking-machine pulsator comprises a body 30, Figs. 1 and 2, in the form of a hollow cube of which four sides are apertured, each aperture 31 being closed by a resilient diaphragm 34 and an associated cap 35 whereby four diaphragm chambers 36 are formed, the admission of air and vacuum to the diaphragm chambers and to the teat cups being controlled by a pair of reciprocating slide valves 49, Figs. 1, 2, 10, 21 and 69, Figs. 1, 2, 10, 16 and 20, which are connected to oppositely disposed diaphragms and therefore move at rightangles to one another. The lower part of the body 30 is provided with a frame cross 37 which merges into a central vertical part 38 hollowed out to form a taper socket 40 fitting over a taper plug on the cover of the milk pail. The part 38 is provided with two chambers 42, communicating through bores in two diametrically opposed arms of the cross 37 with nipples 43 adapted to be connected by flexible pipes to the claws of the teat cup clusters, whilst a bore in a third arm of the cross 37 communicates at one end with the socket 40, and hence with the milk pail, and is provided at the other end with a nipple 44 adapted to be connected to the vacuum pump. The part 38 is provided with a flat top 39 provided on the. corners with four posts 45 of different diameters over which are fitted a lower stationary valve plate 46 and an upper stationary valve plate 59. The lower slide valve 49 slides between the stationary plates 46, 59, and the upper slide valve 69, the underside of which is shown in Fig. 16, slides on the upper plate 59, both valves being guided by the posts 45. The plates 46, 59 are formed of hardened stainless steel and the valves 49, 69 of brass or other relatively soft material, whereby friction is reduced and oiling rendered unnecessary. The plate 46 is provided with a central hole 47 communicating with the socket 40, and with side slots 48 communicating with the chambers 42. The lower slide valve 49 is provided with a central slot 51, Fig. 21, with oppositely disposed grooves 56, 57, and with grooves 52, 53 communicating respectively by bores 54, 55 and holes in the diaphragms with the diaphragm chambers situated in the east and the west positions as viewed in Fig. 2. The upper plate 59 is provided with nine holes 60 .. 68. The upper slide valve 69 is provided on its under-surface with a groove 70, Figs. 16 and 20, into which opens a pin-hole 73, the ends of the groove being continued to form offset grooves 71, 72, with oppositely extending grooves 78, 79 provided at the ends with holes 80, 81 respectively which open into a circular groove 84 on the upper surface of the valve, and with grooves 74, 45 communicating respectively through bores 76, 77 with the north and south diaphragm chambers. A post 85, Fig. 20, projects from the upper surface of the valve 69 and is provided with side grooves 86 and an axial threaded bore 87 in alignment with the hole 73. A cross bore 88 connects two of the grooves 86 with the bore 87. An annular filter 89, Fig. 1, surrounds the post 85, the cover 94 being secured by a screw 95 which carries a needle valve 96 co-operating with the hole 73. In operation, air and vacuum are supplied alternately to the nipples 43, and hence to the teat cups, by means of the lower valve 49 which, in the position shown in Figs. 1 and 2, allows vacuum from the socket 40 to be transmitted through the hole 47, the slot 51 in the valve 49 and the west slot 48 to the west chamber 42, whilst the east chamber 42 is open to the atmosphere through the east slot 48 and the opening 58 at the east end of the valve 49. The movement of the lower valve 49 is controlled by the upper valve 69, the construction of the valves and the upper plate 59 being such that, when the lower valve is in the west position, the upper valve 69 moves to the north, and its arrival at the north position causes the lower valve to move to the east. The north diaphragm chamber communicates through the bore 76 and groove 74 in the valve 69 with the hole 63 in the plate 59, and the hole 63 communicates with the groove 56 in the valve 49 in all positions of the valves. Similarly, the south diaphragm chamber is at all times in communication with the groove 57 in the valve 49. When therefore the valve 49 is in the west position, as shown in Figs. I, 2 and 10, the north diaphragm chamber is connected through the groove 56 with the hole 62 in the plate 59, which hole is always in communication with the groove 79 on the plate 69 ; the groove 79 communicates through the hole 81 and groove 84 with the filter 89. The filter communicates through the grooves 86, the bore 88 and the hole 73 with the groove 70 in the valve 69, which groove always communicates with the central hole 64 in the plate 59 and thence, through the central slot 51 in the valve 49 and the hole 47 in the plate 46, with the socket 40. Hence with the valve 49 in the west position, vacuum is applied to the north diaphragm chamber, the air extracted therefrom being filtered before reaching the pin-hole 73, wlilst at the same time the west end of the groove 57 in the valve 49 is uncovered and air is therefore admitted to the south diaphragm chamber. Consequently the valve 69 moves to the north position at a speed depending upon the setting of the valve 96. When the valve 69 reaches the north position, as shown in Fig. 10, the holes 67, 68 in the plate 59 are uncovered, and air passes through these holes and the groove 53 and bore 55 in the valve 49 to the west diaphragm chamber. At the same time suction is applied from the socket 40 to the east diaphragm chamber through the hole 64 in the plate 59, the groove 70 on the valve 69, the hole 60 in the plate 59, and the groove 52 and bore 54 in the valve 49. As the valve 49 begins to move to the east, the groove 52 slides over the hole 61, which is already connected to the groove 70 through the curved extension 71 and hence to vacuum, and this gives the valve 49 an added impetus so that it moves quickly to the east position. As soon as the valve 49 reaches its east position, the groove 56 is uncovered and admits air to the north diaphragm chamber, whilst the south diaphragm chamber is connected through groove 57, hole 66, groove 78, hole 80, groove 84, air filter 89, and hole 73 to the vacuum in the socket 40. The valve 69 now moves to the south position, whereupon the holes 60, 61 are uncovered and air is admitted through the groove 52 and bore 54 to the east diaphragm chamber whilst the west diaphragm chamber is connected to vacuum through the bore 55, groove 53, hole 68 and groove 70. Hence the slide 49 moves back to the west position and the cycle recommences.