Patent GB-485638-A (GB)
Title: Improvements in petrol pumps
IPC: B67D7/26
Filed: 1936-08-17
Abstract: 485,638. Dispensing petrol &c. SUTTON, E. S., and BELL, T. A. Aug. 17, 1936, No. 22616. Void. Convention date, Sept. 3, 1935. [Class 116] An apparatus for dispensing liquids, particularly petrol, has order and delivery indicators which are locked against manipulation during delivery. Delivery can be commenced only after both indicators have been zeroized after completion of the delivery of a preceding order. In emergencies, delivery can be manually interrupted but in this case means for completing the interrupted delivery are accessible only to an authorized person. General construction. The pump 14, Fig. 1, driven by an electric motor 12, draws from an underground reservoir 11 and delivers through a pipe 16 to a flow meter 25 and thence past a valve 24 to a hose having a nozzle 13. A valve 17 in a pipe 18 allows the liquid discharged from the pump to be returned to the reservoir 11 when the valve 24 is closed. An order indicator 21 is pre-set to indicate the required quantity of liquid and a flow indicator 23 is driven by the flow meter until it registers with the order indicator, whereupon the valve 24 is closed. Control system. The motor is controlled either by a manual switch or automatically by a switch governed by the hose nozzle. The order indicator 21, Fig. 2 is fixed on a disc 28, and at the zero position of the flow indicator 23, a switch 31 is closed thus enabling a manual switch 35 to be operated to energize a solenoid 32 and close a switch 33. When the order indicator 21 is moved forward from the zero position, at the pre-setting of the apparatus to deliver a specified quantity of liquid, switches 29a and 30a are closed thereby completing a circuit through a solenoid 22 and opening the discharge valve 24. Delivery then takes place and the flow indicator 23 moves into register with the pre-set order indicator, whereupon the switch 29a is opened thus allowing the discharge valve 24 to be closed by a spring. The movement of the delivery indicator 23 from zero opens the switch 31 breaking the circuit through the solenoid 32, but the switch 33 is held closed by the solenoid 34 in series with the switches 29a, 30a, until the opening of the switch 29a breaks the circuit through the solenoid 34 and opens the switch 33. The discharge valve 24 cannot normally be re-opened until the indicators are zeroized. In emergency, flow can be interrupted before delivery of the pre-set quantity by manually opening a switch 30a which breaks the circuit through the solenoid 22 of the discharge valve. As, in this case, the flow indicator will have moved from zero, the switch 31 will be opened, and the circuit through the solenoid of the discharge valve can then only be completed to re-open the valve for delivery of the remainder of the pre-set quantity, by a manually operated emergency switch 36 which is locked so as to be accessible only to an authorized person. Control mechanism. The mechanism for operating the above control system comprises a spindle 37, Fig. 4, having push buttons 40 at its ends, and slidable within a shaft 52 having manual control knobs 93, so that the shaft may be turned to set order indicators 21 mounted thereon, to the required figure on dials 20. A wheel 72 free on the shaft 52 is driven through gearing 71, 27 by the flow meter and carries a knife-edged disc 74, a sleeve 76 with a radial arm 75 being freely mounted on the hub of the wheel 72. The arm 75 carries the flow indicators 23 and also has pivoted thereon an arm 82 with cork facing 87 which may be clutched to the disc 74 so that the flow indicator may be driven by the flow meter. The arm 82 is yieldingly coupled by a spring' 83 to a second arm 68 pivoted on the radial arm 75, the arm 68 wiping over the rim of a disc 28 integral with the shaft 52, during delivery, until a radial slot 53 in the disc 28 allows the arm 68 to swing and declutch the indicator 23 from the flow meter. The inward swing of the arm 68 also actuates a push rod 39 guided on the face of the disc 28 and passing through a slot 38 in the spindle 37, to swing a shaft 47 carrying a switch lever 48 governing a switch 49 on the disc 28, the opening of the switch breaking a circuit through the solenoid of the discharge valve to cut off delivery. The shaft 47 may also be rocked by a yoke 43, Fig. 3, guided in the disc 28 and having a plunger 30a, Fig. 4, adapted to seat in a V-notch 41 in the spindle 37 during normal working, and an upper extension 45 which is pointed to engage notches 60 in a fixed ring 46, the notches 60 corresponding to the units of delivery and serving in conjunction with member 45 to position accurately the disc 28 at pre-setting. The fixed ring 46 has ratchet teeth 58 on its periphery, the teeth being interrupted in the region of each notch 60 to enable accurate pre-setting to be effected. The ratchet teeth are engaged by a spring-pressed pawl 61 pivoted on the disc 28, so that the order pointer cannot be reversed when presetting. The tail of the pawl is depressed by the arm 68 to disengage the pawl from the teeth at the completion of delivery, thus permitting zeroizing to be effected. A fixed cam 66 lifts the arm 68 clear of the notch 53 in the disc 28 when zeroizing, whereby the pawl 61 is re-engaged with the fixed ring 46 and the push-rod 39 allowed to rise to close the switch 49. This movement also closes the switch 31 by means of a spring arm 67, 168. An extension 88 of the clutch arm 82 is bevelled at diagonally opposite corners 89, 90 to engage a flexible guide 91 so that the clutch is held engaged during delivery but is maintained disengaged during zeroizing when the arm 68 is lifted by the fixed cam 66. In emergency the push button 40 may be pressed thus actuating the plunger 30a and opening the switch 49.