472,263. Cow - milkers. JOHNSON, H. H. March 18, 1936, No. 8153. [Class 84] A vacuum - actuated milking machine with single-chambered teat cups 1 and a milk receiving unit 30 under constant vacuum is provided with a milk claw 16, Figs. 1, 6, connected to the teat cups 1, and with pulsatory means whereby air is intermittently admitted to and exhausted from the claw 16, a constant vacuum milk pipe 27 leading from the milk receiving unit 30 to the claw 16 with the interior 17 of which it communicates through a restricted passage 24 so that air admitted to the claw 16 by the pulsating means will be partially exhausted therethrough from the teat cups 1, the partial vacuum thus created in the teat cups retaining them on the teats during the period they are not under suction. As shown, the milk receiver 30 consists of a glass vessel into which depends a pipe 31 leading to the main milk pipe 32. The vessel is attached to a cover 37 by clips 40 screwed to the cover and a pin 42 which is under tension of a spring 43. The milk pipe 27 is connected to port 29 in the cover. The chamber 17 of claw 16 is connected through a nipple 18 provided with a small air opening 63, a pipe 33, and a nipple 34, Fig. 2, to pulsation means consisting of a slide valve 35 which is reciprocated over a valve face 44 formed on an extension 39 of the cover. The valve 35 has a hole 51 and a groove 48 by which the nipple 34 and consequently the teat cups 1 are alternately connected to the atmosphere and, through port 36, to the receiver 30 which is under vacuum through pipe 31. The valve 35 slides in vertical guides secured to the face 44 and is actuated by the engagement with a fork 50 thereon of a rod 52 the top end of which is connected to a shank 53, which is held by a spring 55 against a cam 54, operated by a rotating rod 56 extending the entire length of the cow bails. The spring 55 is attached at one end to the bearing 57 of shank 53, and at the other end to a cup 56a which is adjustably secured on rod 52 to enable the tension to be varied and which serves as an oil-trap. Alignment is maintained by an angle-iron 58 extending between cover 37 and bearing 57. In a modification, Fig. 14, the pipe 27 is attached to a nipple 65 on a connection 66 of the main milk pipe 32, and pipe 33 to a nipple 67 on a base 68 of a slide-valve 71 similar to valve 35 and actuated by a reciprocating rod 72 and relating the nipple 67 alternately to the atmosphere and to the pipe 32. The teat cups may consist each of a body 1, Figs. 11, 12, of resilient material, e.g. moulded rubber, having at its upper end a flange 3 for gripping the teat 5 and a bulge 6 which acts as a stiffening and supporting means. The body is formed with four ribs 8 between which are grooves 9 outside one opposite pair of which are formed strengthening ribs 10, so that when vacuum is applied to the interior the body will collapse along the other pair of grooves and the ribs 8 will press on the teat 5.