Patent GB-313711-A (GB)
Title: Improvements in pulsators for milking machines
IPC: A01J5/10
Filed: 1928-04-30
Abstract: 313,711. McCornack, H. April 30, 1928. Cow-milkers.-In pulsator mechanism for milking apparatus a piston having a valve body slidable on the pulsator body works in a removable cylinder head which is supported by the piston. The pulsator body 20 has opposed inclined faces on which slide operating and control valve bodies 29, 32, held in engagement with the faces by suction and gravity, and the faces are interconnected by passages having respectively end ports 47 and 49, 48 and 50<a>, 68 and 67, and 73 and 74. Removable cylinder heads, 33, 34, 36, 37 are supported by pistons at the ends of the valve bodies and are prevented from moving endwise by the engagement of flanges 83 with the ends of the pulsator body and by the engagement with the flanges 83 of flanges 82 and fingers 84 on a bent plate 77. The cylinder heads are put into communication with atmosphere by ports 50, 51, 55, 59 and passages 52 - - 58, Figs. 8 and 9, and into communication with suction by ports 43, 39, and passages 42, 41, 40, 38, 21, Fig. 3, the valve bodies having co-operating grooves or recesses 64, 65, 72, 69, Fig. 4, and 66, 75, 76, 61, 60, and passages 70, 71 and 62, 63. In operation, ports 60, 61 and 69, 72 in the valve bodies connect at all times with ports 49, 50a and 68, 73 respectively, and, with the parts in the position shown, owing to the coupling of ports 48, 51 by the recess 64, the cylinder head 36 is connected to atmosphere; similarly, owing to the coupling of ports 47, 43, by the recess 65 the cylinder head 37 is connected to vacuum. The control valve body 32 will in consequence now be moved to its opposite end position, and as it approaches this position (1) the recess 66 puts the suction port 39 into communication with the port 67 so that through port 68, recess 69 and passage 70 suction is communicated to the cylinder head 34, and (2) the recess 75 connects the ports 59, 74 so that the cylinder head 33 is put into communication with the atmosphere; as a result, the operating valve body 29 will be moved to its other end position. A recess 31 in the valve body 29 serves to connect the port 27 alternately with an air port 26 and with a suction port 24; in this manner, through nipples 16, Fig. 3, pulsations are transmitted to the teat cup chambers and through a nipple 19 they are also transmitted to the diaphragm box 17 of the bucket-oscillating device. For controlling and limiting the speed of operation of the pulsator a needle valve 44 is adjustable towards, and from, a seat at the upper end of the restricted passage 41, and the valve has a stem 46 which is of such length that it extends through the passage in every operative position of the needle valve. A leather &c. gland 45a around the shank of the valve and pressed against a conical seat in the pulsator body by a screwthreaded bushing 45, serves to prevent both leakage and creeping out of adjustment of the valve. A cupped leather 85 on each piston head is retained in position by a flanged sleeve member 86, and the flanged portion of the leather is pressed outwards by a coil spring 88. For lubricating the moving parts, oil holes in the plate 77 overlie shallow recesses 90 in the pulsator body and these recesses communicate by channels 91 with. the front and rear faces of the body; some of the oil is thence carried by suction to the cylinder heads. Specification 295,349 is referred to.