GB788961A - Improvements in vacuum-operated master pulsators for milking machines - Google Patents

Abstract

788,961. Pulsators. SEABORNE, T. L. Oct. 22, 1956, No. 32110/56. Class 84. A master pulsator having two coupled diaphragms of unequal area to form an unbalanced system, has two further diaphragms coupled to the first two and acting as valves for controlling the vacuum and pressure cycle which in turn actuates the unbalanced system. Vacuum applied at 39 is communicated to the underside of diaphragm 8 (atmospheric pressure being maintained between the diaphragms in chamber 40) ; thus this diaphragm experiences a downward force. At the same time vacuum builds up in chamber 36 as the air therein bleeds at a rate controlled by a nozzle 35 through 34 and 37. An upward force is thus produced on the diaphragm 9 and the coupled diaphragms 8 and 9 eventually move upwardly when the force on 9 prevails over that on 8. The valve diaphragms 6, 7 then move to the upper position and vacuum is established via 38, 26, 41, 42 in chamber 40 and atmospheric air leaks into 36 via chamber 33 bore 34 and nozzle 35. This eventually brings about a downward movement of the diaphragms to their initial position as shown. The pulsations in chamber 28 are coupled to the relay pulsators by pipe 30. Nozzle 35 may be changed to change the pulsation rate and additional control can be exercised by adding glass beads on a screen 46 to chamber 36 to vary its effective volume.