Patent GB-788507-A (GB)
Title: Apparatus for mixing two liquids together in predetermined quantities
IPC: G01F11/02
Filed: 1953-08-06
Abstract: 788,507. Mixing liquids. MOUNTFORD, L. A., and MOUNTFORD, I. J. Aug. 6, 1954 [Aug. 6, 1953], No. 21719/53. Class 86 [Also in Group XXVIII]  In apparatus for distributing a mixture of two liquids, for example petrol and oil, in which the movements of a first piston in a first cylinder receiving for example petrol, cause the movement of a second piston in a second cylinder for receiving, for example, oil, the movement of the first piston is caused either by the thrust of the petrol admitted under pressure or is effected manually and the oil delivered by the second piston is fed into a duct admitting the oil into the first cylinder adjacent to where the petrol enters the latter cylinder so that the oil is mixed intimately with the petrol. The apparatus shown in Figs. 2, 3 and 4 comprises a metering chamber 3 having a valve-controlled inlet 2 for connection to a supply of petrol under pressure and being provided with a piston 4 and hollow piston rod 6. The rod 6 has a rack 21 co-operating with a gear wheel 38 which is connected to a shaft 37 through pawl and ratchet mechanisms whereby shaft 37 completes a full revolution during the outward or "charging" stroke of the piston. The shaft 37 carries a wheel 40 which is connected to a piston 45 in a cylinder 32 functioning as an oil pump. The oil is supplied through a passage 84 from a bottle 94 detachably connected to the cylinder wall. Valves 89, 79 are provided at the mouth of the bottle to prevent oil flow through passage 84 unless when suction is applied by the oil pump. The cylinder 32 is provided with a second piston 49 formed with three longitudinal grooves 51 52, 53, the groove 51 communicating with the passage 84, the groove 52 co-operating with a set screw 54 to prevent rotation of the piston 49 and the groove 53 being adapted to communicate by way of valve 56 with the cylinder 3. The piston rod 58 has a screwthreaded portion 59 formed with a flat 60 on which are fitted stop washers 61 each provided with a lug 62, the lugs being differently disposed angularly. A rotary cap 66 provided with a lug 71 is mounted on the end of the cylinder 32 and the position of the cap determines which of the lugs 62 will engage the lug 71 during the stroke of the piston 49. The cap has markings indicating the measure of oil to be supplied. As the piston 45 is drawn rearwardly by rotation of the wheel 40, the piston 49 closely follows the piston 45 until stopped by a lug 62 engaging the lug 71, whereupon continued movement of piston 45 sucks in oil from the bottle 94. On return of piston 45 this oil is forced past valve 56 into cylinder 3 to mix with the petrol therein. The apparatus is set into operation by the pulling of a trigger 30 to actuate a pivoted plate 101 whereby petrol inlet valve 8 is opened and outlet valve 12 is closed. Petrol forces the piston 4 along the cylinder until it reaches an end plate 20 whereupon a lug 104 connected to the plate 101 is freed from engagement with a key 22 on the piston rod 6, allowing the pivoted plate 101 to swing to its initial, position so that valve 8 is closed and valve 12 is opened. The piston 4 is returned by pressure of spring 23 and discharges the mixture of oil and petrol through pipe 19. The inlet 2 may be attached by a flexible conduit to a point between the air separator and the meter of a conventional electrically-driven kerbside pump. The apparatus shown in Fig. 7 is manually operated to turn through ratchet and pawl mechanism a cam assembly 158 formed on its interior with a cam track 159 arranged to co-operate with a cam follower 160 rotatably secured to a bearing pin on a collar. 161 attached to the piston rod 6. As the handle 169 is turned the piston 4 is drawn away from cylinder head 110, whereby petrol is drawn into the cylinder 3 together with oil supplied by the oil pump. When the cam assembly has completed a revolution a spring actuated locking rod 171 enters a hole 174 in plate 162 preventing further rotation of the cam assembly until the piston 4 has returned to its initial position under spring influence, to effect the discharge stroke