Patent GB-872918-A (GB)
Title: Improvements in or relating to fluid metering devices
Inventor: MOORES JOHN ROBERT
IPC: G01F11/02
Filed: 1959-03-03
Abstract: 872,918. Delivering measured quantities of liquid. CASTROL Ltd. April 12, 1960 [March 3, 1959], No. 7403/59. Class 106(5) [Also in Group XXXIV] A metering device to which fluid at high pressures is supplied alternately through two lines 29, 30 comprises a change-over valve B responsive to the pressure changes in the supply lines, and a cylinder J having a two-part piston Q, R reciprocable in it by the high pressure fluid applied alternately to its opposite ends so as to drive the fluid in front of the piston out through discharge outlets K, one part Q of the piston being arranged to co-operate with ports 9, 11 in the cylinder to act as a change-over valve for the supply of fluid to the two inlets of a further metering device and the other part R being arranged to abut an adjustable stop P to vary the amount of liquid discharged. As applied to a lubrication system, the change-over valve B is in the form of a spindle slidable in a bore in a block A and grooved at 1, 2 to control communication between ports 7, 3, 4 and 5, 6, 8, the ports 7, 8 being in communication with the two lines 29, 30. The ends of the spindle project through plugs C and give an external indication of the position of the valve. The ports 3, 6 communicate with the first measuring cylinder in the block J through ports 9, 10 in this cylinder and the ports 4, 5 communicate through channels 15, 16 and ports 17, 18 in the block J with discharge outlets K on either side of the block J. The two-part piston Q, R consists of an outer piston sleeve Q, having a constant stroke in its measuring cylinder and provided with recesses 21, 22 to control communication between the ports 9, 11, 12 and 10, 13, 14, and an inner piston R reciprocable within the piston sleeve Q and the stroke of which is adjustable by the screw P to vary the amount of liquid discharged at each operation. The ports 12, 13 communicate through further channels 15, 16 and ports 17, 18 in a second block J with a second set of discharge outlets K in this block and also through these channels with ports 19, 20 in the second measuring chamber. Further measuring chambers may be fitted to the assembly. The ports 11, 14 in the last measuring chamber communicate through supply lines 23, 24 with a further metering assembly of the same type or the supply lines 23, 24 may be closed by plugs W, and the ports 12, 13 by a block T. A flow-sensitive or pressure sensitive device may be connected between the outlet lines 23, 24 of the last measuring device in the series to indicate the satisfactory functioning of the device. A test plug containing a ball valve is provided in the block A to determine the availability of the lubricant supply to the device. In operation, high pressure fluid applied at the supply line 29 moves the valve B along its bore to drive a small quantity of fluid into the line 30 and also to bring ports 7 and 3 into communication, thus allowing the high pressure fluid to be supplied to the first measuring cylinder. The high pressure fluid thus applied displaces the pistons Q, R of this cylinder along the bore to eject the contained fluid at one end out through the ports 10; 6, 2, 5, 16, 18 and the right-hand outlet K in the block J, the displacement of the piston sleeve Q uncovering the port 11 so allowing the high pressure fluid to be applied to the second metering device, the contained fluid being ejected through channels 10, 14, recess 22 in the first piston sleeve Q, port 13, groove 16, port 18 and the right-hand outlet K in the second block J. The displacement of the piston sleeve Q uncovers the channel 11 which may either be blocked or connected at 23 or 24 to the supply inlets of another similar group of measuring devices. In the latter case, the fluid ejected by the valve B of the second group passes into the supply line 30 which is connected at 24 to the right-hand outlet of the last measuring device of the previous group and passes through channels or ports 14, 22, 20, 16, 18 to the right-hand outlet K to supplement the quantity of fluid ejected by the pistons Q, R of this measuring device. When the last measuring device in the last group has been operated and further movement of lubricant then prevented by an end plug, the build-up of pressure in the supply line 29 may be used either to operate an automatic changeover device which will then apply the high pressure to the other supply line 30 or to operate a device to indicate to the operator that the high pressure should be applied to the other channel. The device, after change-over, operates in the same way as before except that discharge is through the left-hand outlets K in the block J. The left and right outlets K, however, may be connected and one of them blocked so that discharge from a given measuring device always occurs through the same outlet. Specifications 763,078 and 831,686 are referred to.