Patent GB-479288-A (GB)
Title: Improvements in or relating to liquid delivery apparatus
IPC: B67D7/08
Filed: 1936-07-30
Abstract: 479,288. Dispensing liquid fuel &c. FIRSTBROOK, H. T. July 30, 1936, Nos. 21161 and 35666. [Class 116] An apparatus for dispensing metered quantities of petrol or other liquids and having means for zeroizing an indicator driven by the meter prior to a fresh dispensing operation, is provided with interlocking mechanism which necessitates the zeroizing means making two movements in a definite sequence before delivery can commence, the first of these movements resulting in the zeroizing of the indicators whilst the second movement, which is an automatically effected reverse movement and is conditional upon the completion of the first movement, releases a locking device from exercising constraint on a member such as a pump motor switch, the handle of a manually operated pump, or a valve, controlling delivery. Two embodiments of the invention are described. In the first embodiment, the meter shaft 1, Fig. 1, drives through bevel-gearing 2, 3 and a one-way clutch 6, a shaft 4 journalled in columns 5. Wheels 7 on the shaft 4 drive through gear wheels the drums 9, e.g. half-gallon, gallon and ten gallon indicators, of counters provided with windows 12 on opposite sides of the apparatus. The drums 9 are mounted to rotate freely on shafts 10, Fig. 2, but pawl devices 14 are provided so that the drums may be zeroized by a rotation of the shafts 10. Zeroizing is effected by a handle 16 coupled to a shaft 15 which is geared by wheels 18, 19, 20 to wheels on the shafts 10. A cam 21 fast on the shaft 15 has a slot 22 receiving a pin 23 carried by a swinging plate 24 pivoted at 25, the pin 23 also working within an approximately radial slot 50 in a member 49 on the face of a disc 42 free on the shaft 15. The plate 24 is linked at 27 to shutters 28 which screen the windows 12 during zeroizing movement of the counter drums. A cam 29, also fast on the shaft 15 has a step 31 which, by contact with a pawl 30 prevents reverse movement of the shaft 15 once a zeroizing movement is commenced and thereby necessitates the performance of the full cycle of zeroizing movements before a fresh delivery can be effected. A member 47 for actuating a pump motor switch &c. to control delivery, has a blade 46 which can pass into radial slots 45 in discs 42, 41, 44 provided these slots are aligned, delivery of liquid only then being possible. The disc 41 is fast on the shaft 15 and the disc 44 is freely mounted on a boss 43 on the disc 41. A pin 52 on the disc 41 works within an angular gap 51 in the disc 44, Fig. 5, and is coupled to the disc 44 by a spring 53. An arm 33 frictionally held by a clutch 34 on the shaft 15 has a pin 38 engaged normally by a hook 37 on a pawl 35 pivoted at 36, but is releasable so as to move into the path of a stop 32 on one of the wheels 7 when zeroizing. At the end of a delivery operation the blade 46 is raised by actuation of the member 47 this movement causing a lug 61, Fig. 5, on the blade to trip a pawl 56 thereby allowing the disc 44 to turn under the influence of the spring 53 to an extent determined by the gap 51, thus preventing further operation of the member 47 to start delivery. When a fresh dispensing operation is to be effected, the zeroizing handle 16 is turned and thereby rotates the shafts 10 which move the indicating drums 9 on to zero. This movement of the shaft 15 rocks the plate 24 and raises the shutters 28 to screen the windows 12. A step 40 on the cam 29 operates the tail 39 of the pawl 35 during this movement and thus frees the arm 33 which swings into the path of, and forms a positive stop at the zero position for, the abutment 32 on the wheel 7, this wheel and the shaft 4 having been turned by the gearing 8 from the drums 9, the one-way connection 6 avoiding any necessity for turning the meter spindle 1 during this operation. The movement of the plate 24 during zeroizing imparts an angular displacement to the disc 42 by means of the pin 23, and this displacement prevents the possibility of any actuation of the control member 47 until, after completion of the zeroizing movement, a further movement is given to the shaft 15 to restore the slot 45 in the disc 42 to alignment with the. blade 46. This further movement is effected in the present embodiment by the spring 26 which automatically imparts a reverse angular movement to the shaft 15 on release of the handle 16 after the pin 23 enters the slot 22 in the cam 21 at the zero position. Meanwhile the inertia of the disc 44, which may be increased by a weight 62, carries the disc 44 onwards after the completion of zeroizing, sufficiently to allow the pawl 56 to re-engage with the step 55 and so maintain the slot 45 in the disc 44 in alignment with the blade 46. Thus the slots 45 in all three discs 41, 42, 44 have been returned into alignment with the blade 46, enabling the control member 47 to be actuated to start delivery. The final reverse movement of the shaft 15, after zeroizing, returns the arm 33 into engagement with the hook 37, so as to be clear of the stop 32, the shaft 4 being thereby left free to be driven by the meter spindle 1 during delivery. The entry of the blade 46 into the radial slots 45 at the commencement of the dispensing operation prevents any further interference with the resetting mechanism. In the second described embodiment of the invention, a switch or other control handle 201, Fig. 7, is fixed on a shaft 202 journalled in a bracket 204, the shaft carrying an interlock blade 205 which co-operates with two radially slotted discs 206, 207. The disc 206 is fast on a spindle 211 journalled in the bracket 204 and is coupled at 213 to a resetting shaft (not shown). The disc 207 is free on a boss on the disc 206 and is adapted to be driven from the disc 206 by a pin 215 fixed therein, the pin working in an arcuate gap 216, Fig. 8, in the disc 207. A spring 217 secured to the disc 207 and to the pin 215 tends to turn the disc 207 relatively to the disc 206 to misalign the slots therein. The disc 207 has a step 219 engaged by a latch 221 pivoted at 222, Fig. 6, the latch having also a toe-piece 225 engaged by one arm 229 of a bell-crank 226 which is biassed by a spring 228. When a dispensing operation is completed the control handle 201 is depressed thereby withdrawing the interlock blade 205 from the radial slots in the discs 206, 207 this movement of the blade tripping the latch 221 and allowing the disc 207 to turn through an angle determined by the gap 216 whereby the radial slot in the disc 207 is angularly displaced from the plane of movement of the blade 205, so that actuation of the control member to commence a fresh delivery is prevented. The tripping of the latch 221 allows the arm 229 to swing under the toepiece 225 to maintain the latch in raised position. When a fresh dispensing operation is to be effected the zeroizing handle (not shown) is turned and rotates the spindle 211 and both the discs 206, 207 until, in the zero position, the slot in the disc 207 is aligned with the blade 205. Meanwhile a cam 230 on the shaft 211 has actuated the bell-crank 226 to release the latch 221 which falls and, at the zero position, engages behind the step 219 of the disc 207 to prevent reverse displacement of the slot thereof out of alignment with the blade 205. Owing to the angular displacement of the slots in the disc 206, 207 at this stage a reverse movement of the resetting shaft is necessary after zeroizing to align the slot in the disc 206 with the blade 205, before the control member 201 can be actuated to commence delivery and this reverse movement is effected automatically by a spring. The operating member such as the handle 47 or 201 is preferably coupled to the member controlling delivery through a strong spring which transmits normal working movements, but yields under abnormal strains. The handles 47, or 201 may be adapted to support the hose nozzle when not in use so that the replacement of the hose nozzle after a delivery operation automatically puts the interlock mechanism into operation.