| 摘要 |
<p>1317806 Liquid dispensing apparatus TOKICO Ltd 31 July 1970 [31 July 1969 16 Sept 1969] 37176/70 Heading A4T [Also in Division F1] A supply pipe 10 through which a desired fixed quantity of liquid e.g. either 1 or 2 Kls petroleum is fed to a road tanker has a flowmeter 12 and stop valve 13 which is fully opened against biasing means by means of an actuator 49 when subjected to a high pressure e.g. 1.4 Kg/cm<SP>2</SP> in a line 41 or is opened only slightly by a low pressure e.g. 0À2 Kg/cm<SP>2</SP> in a line 42 with line 41 vented; the pressure in line 41, 42 being maintained or vented through valves 33, 34 controlled by fluidic devices in response to the amount of liquid having passed through the meter 12. The meter drives a perforated disc 45 located between a low pressure air delivery nozzle 46 connected to line 42 and a receiver nozzle 47 which thus delivers air pulses through a line 50 and a two-position shuttle valve 35 to one or other pre-set counters 36, 37 according to whether 1 or 2 K.I. are to be passed through the meter 12. The high pressure air supply for line 41 is derived from the inlet 26T of changeover valve 33 when switched from the position shown and which is effected by application of control air-pressure at its end 33B. This control pressure is derived from the outlet 30-6 of a flip-flop 30 when its control inlet 30-2 is connected to a source 26A on depressing a start valve 20. The low pressure supply for line 42 is similarly derived from the inlet 26K of valve 34 controlled by a flip-flop 31 which also has its control inlet 31-2 connected through push valve 20 to 26A. Near the end of liquid delivery, pre-set counter 37 delivers air from its output 37B to a control input 30-4 of flip-flop 30 which is thus switched to the position shown whereon line 41 is vented and valve 13 is held in the slightly open position by the low pressure in line 42. Since line 41 is also connected to a control inlet 29-3 of OR gate 29 and line 50 is connected to a further control inlet 29-2, venting of line 41 results in pulses being fed from outlet 29-4 to signal inlet 38A of a further pre-set counter 38 which when the desired liquid delivery through meter 12 is completed delivers a signal at 38B to the control inlet 31-4 of OR gate 31 which thus switches valve 34 to the vent position whereon valve 13 closes completely. A safety device for venting lines 41, 42 unless the tanker is electrically earthed prior to or during loading comprises a valve 24a in the position shown when the earth wire is not attached thereby connecting a pressure source 26B to the control inlet 28-3 of an OR gate 28 having its outlet 28-5 connected to control inlets 30-3, 31-3 of flip-flops 30, 31 which are thus switched so that their outlets 30-5, 31-5 are connected to the ends 33A, 34A of valves 33, 34 resulting in the latter being vented. An emergency stop valve 21 is also connected to control inlet 28-3. If due to residual liquid in the tanker a bubbler tube 23 is obstructed by the liquid level, air-pressure from a source 26D gains access to the control input 27-3 of an OR gate 27, the output at 27-6 is directed to a control input 28-2 of gate 28 resulting in switching of valve 33, 34 to their vent positions. In a modification the meter 12 drives two cam discs (87, 89) Fig.3 (not shown) at fast and slow speeds and which discs close normally open valves 91, 92 at low pressing air sources (62C, 62B) which form control inputs for various logic switching elements.</p> |
