Patent GB-484321-A (GB)
Title: Improvements in or relating to fluid measuring and delivering apparatus
IPC: G01F15/07
Filed: 1936-12-01
Abstract: 484,321. Dispensing liquid fuel &c. FIRSTBROOK, H. T., and WAYNE TANK & PUMP CO., Ltd. Dec. 1, 1936, No. 32975. [Class 116] Apparatus for dispensing measured quantities of petrol or other liquid, in which the liquid is pumped by an electric motor from a storage tank through a positive flow meter to delivery, has a switch-operating member driven in step-by-step manner by the flow meter to cut out the motor after the delivery of a predetermined maximum quantity, resetting means being provided to return the operating member to initial position when a main motor control member is moved to " off " position. The apparatus may have a main switch (not shown) controlled through a rod 8 by a lever 7, which may be a nozzle-supporting hook, and an auxiliary switch 51, in series with the main switch, controlled by a rod 45 coupled to an arm 43 secured to a spindle 17 which also has secured thereto a plate 20 provided with ratchet teeth 21, 22 at its ends. A shaft 25 coupled to the indicating mechanism is driven by the flow-meter shaft 1 through gearing, and drives a counterweighted pawl 31 by means of an eccentric 26, thus rotating the plate 20 step-by-step and raising the rod 45 until, when the lost motion provided by the slot 47 in the rod is taken up, the auxiliary switch 51, which may be a tilting mercury switch, is opened and the pump motor stopped. Retrograde movement of the plate 20 is prevented by a counterweighted pawl 36. The plate 20 is reset to initial position, determined by an adjustable screw 72, by a spring 33 when a rod 61 coupled to the end of the main control lever 7 is raised to rock a cam plate 53 by means of a pin 60 and thus disengage the pawls 31, 36. A lost motion slot 62 is provided in the rod 61 so that the cam plate can be rocked, independently of the lever 7, by a rod 63 coupled to the pin 60 and actuated by a press-button 68 through a bell-crank 64, this mechanism enabling successive deliveries or continuous deliveries to be effected merely by manipulation of the press-button, since whenever the pressbutton is operated the cam 53 disengages the pawls 31, 36, thereby allowing the plate 20 to re-establish the circuit through the switch 51. Mechanism of known kind for zeroizing the indicators may be provided, and interlocking mechanism, such as is described in Specification 479,288, may be fitted to prevent the resetting of the indicator unless the control lever 7 occupies the " off " position and also, if desired, to necessitate the resetting of the indicator before the control lever can be moved to the on " position, once it has been moved to the off " position. In a modification, a single switch only is employed, this switch being normally closed by a spring. The switch may be opened by a rod 8, Fig. 5, actuable in one direction only by the control lever 7, or may be opened by linkage 101 ... 105 operated by a ratchet-toothed plate 20 which is actuated step-by-step by a pawl 31 driven by the flow meter. In the latter case, the link 105 engages a stop 110 on the rod 8 to lift the same after a predetermined quantity of liquid has been delivered. A cam plate 53 to release the pawls 31, 36 to enable the plate 20 to return to initial position and so permit closure of the switch, is operated by a rod 61 coupled to the control lever 7, lost motion being provided so that the cam plate may also be controlled by a press-button 68 and bell crank 64, Fig. 4, through a rod 63, the bell crank also operating a link 111 coupled to the switch-actuating rod 8. The control lever 7 may be snapped to the " off " or " on " positions by a spring-pressed ball 117 engaging a V-surface 119 on the lever.