Patent GB-591455-A (GB)
Title: Improvement in liquid dispensing apparatus
IPC: B67D7/76
Filed: 1944-07-06
Abstract: 591,455. Petrol pumps. TRIGGS, W. W. (Gilbert & Barker Manufacturing Co.). July 6, 1944, No. 12942. [Class 116] [Also in Group XXVI] In apparatus for measuring and dispensing liquids, particularly motor fuel, comprising a scavenging pump 48 to scavenge air and gases from the supply conduit 16 and prime a metering pump 25 which is driven with a registering mechanism by a hydraulic clutch 35, 36, the scavenging pump delivers fluid to the hydraulic clutch so that the clutch is engaged or released respectively accordingly as liquid or gas is delivered to it. The metering pump is provided by starting the scavenging pump which is of the radially sliding vane type and which exhausts air by its inlet passage 47 from the casing 17 and the pipe 16 and then draws liquid into the chamber 20, Fig. 6, of the casing 17 to the level of the top 21 of a dam 22 which overflows and fills a chamber 23, in which air and gases separate from the liquid and which primes the pump 25. The pump 48 pumps the air through a passage 96 in its shaft 34 into the clutch 35, 36 which is of the vortex ring type from whence it escapes by apertures 107, 108 to a chamber 47 and a stand pipe 49. When the casing 17 is substantially full of liquid the pump 48 supplies liquid to the clutch 35, 36 which is thrown outwardly by the centrifugal force of the rotating driving member 35 of the clutch into the torusshaped pipes 101, 102 of the clutch and as the apertures 107, 108 have not sufficient area to allow all the liquid to escape the pipes are filled and the driven member 36 of the clutch is rotated, which through gears 37-40 and shafts 41, 43 drives the metering pump 25 unless the valve of the nozzle of the delivery hose is closed in which case the clutch slips, and liquid pressure rising in the scavenging pump outlet passage 89 is communicated through passages 94, 95, Fig. 4, to a control piston 72 of the pump 48 the stator 62 of which is moved so that the pump operates at the minimum rate. If the delivery nozzle valve is open the pump 25 which is a three cylinder reciprocating pump draws liquid from the chamber 23 through a gauze 26 and a passage 24 and delivers it through a passage 122 to the delivery hose. The registering mechanism is driven through a couplling 44 on the shaft 41. When the clutch 35, 36 is full of liquid it escapes through apertures 109 into the chamber 47 and eventually raises a float 50 which opens a valve 51 to allow the liquid to be drawn into the chamber 20 and thus prevents the clutch being immersed in the liquid. The scavenging pump 48 comprises a rotor 60 carrying a circularly arranged series of radially slidable blades 61. The stator 62 of the pump is suspended by links 63 one of which is extended to engage the control piston 72. The blades 61 are held outwardly in contact with the stator 62 by two rings 68 in recesses at the ends of the rotor. The outlet passage from the pump 48 to the clutch comprises grooves 90, 91 and apertures 98 in a bearing for the shaft 34 and an aperture 99 in the shaft 34 leading to the interior of the clutch. A casing 106 fixed to the driving member 35, encloses and rotates on the link of the member 36. The pump 48 operates at a low rate during dispensing to skim the top of the air and gas separator chamber 23. If sufficient air collects at the top of the casing 17 to enter the passage 87 leading to the scavenging pump, this air will be supplied to the clutch and if sufficient will release the clutch and stop the dispensing of liquid. Specification 551,582 is referred to.