GB894404A - Reversing device for pressure-lubrication equipment - Google Patents

Abstract

894,404. Valves. SATZGER, E. Aug. 21, 1958 [Aug. 22, 1957], No.. 26883/58. Class 135. A reversing lubricant dosing device with two outlets 7, 8 which are connected alternately with a source of pressurized lubricant 6 and with a pressure-relief line 9, has two consecutivelyactuated leading and lagging control pistons 1, 2, whose piston ends are acted upon by the infeed pressure or by the discharge pressure, and of which the piston 1 controls the connections of the outlets with the source of pressure and the supply line, whilst the piston 2 effects the interconnections of control ducts for the subsequent reversal. The reversing process is initiated by the opening of a maximum-pressure relief-valve 27 that controls the connection of one of the chambers 36, 37 of piston 1 with the pressurerelief line. As shown, inlet pressure is continuously led to the space 15 between the end lands of the piston 1 by a passage 10. Depending on the position of the piston 1 relative to the piston 2, the space 15 is in communication with one of the outlets 7, 8 through one of two passages 14 or 19 in the piston 2. Also, one of the piston chambers 36, 37 is in communication with one of two passages leading via slot 20, or 30 to a chamber 25 which opens to the relief line 9 through passage 26. In operation, after the dosing appliance connected to the outlet 7 has discharged, the infeed pressure rises and causes relief valve 27 to open to enable the infeed pressure to move the piston 1 to its other end position so that it then supplies lubricant to the outlet 8 ; the relief valve closes with the ensuing pressure drop. The outlet 7 is then in communication with the relief line 9 via passages 14, 37, 36, 29, 31 and due to the pressure difference across the piston 2 the latter moves to an upper position where the reverse cycle takes place. A non-return valve 34 is provided in the line 9 and a relief valve 40 in the passage 29. During transit the two piston valves are held in functional relationship by a spring-loaded ball.