Patent GB-472886-A (GB)
Title: Apparatus for the delivery of predetermined volumes of fluid
IPC: B67D7/16
Filed: 1936-04-01
Abstract: 472,886. Operating clutches ; locking valves ; dispensing liquids. MERCER, A. A. April 1, 1936, No. 19145/37. Divided out of 471,075. [Class 80 (ii)] [Also in Groups XVIII and XXIX] Apparatus for the delivery of a predetermined volume of petrol or other fluid comprises a self-metering pump, such as is described in Specification 471,075, [Group XXVI], driven through a spring-engaged clutch which is disengaged by an electromagnet when the latter is energized by trip means actuated after a predetermined number of resolutions of the pump shaft, the latter being arrested by a positive stop on disengagement of the clutch. As shown in Figs. 1 and 2, a member 29, splined on the pump shaft 5, is urged by a spring 32 towards a loose wheel 26 driven from an electric motor, the wheel 26 having a single recess adapted to be engaged by a single clutch dog 30 on the member 29. The opposite face of the latter has a single dog 33 engageable in a single recess in an angularly-adjustable fixed plate 34. The member 29 is controlled by a fork 44 secured on a spindle 68 and connected, with lost motion, to the armature 40 of an electromagnet C. The fork 44 has an extension 47 adapted to be engaged by a spring-pressed catch 48 secured to a spindle 49 which has an arm carrying the armature of an electromagnet R. A member 60, splined on a vertical shaft 59, has clutch teeth engageable with teeth on a loose wheel 58 geared to the shaft 5, and is controlled by a fork 66 secured on a spindle 67 which is linked to the spindle 68 so that the clutch members 29 and 60 are engaged and disengaged in unison. Also splined on the shaft 59 is a sleeve 78 having a projecting pin 79 riding on the end face 76 of a sleeve 73 which is angularly adjustable by means of a hand wheel 86, Fig. 5. The face 76 is in the form of a helical track, the ends being connected by a vertical part 77. The sleeve 78 has a flange 80 which, as the sleeve is raised, freely passes a trigger 82, but, when the pin 79 rides over the peak of the track 76 and falls down the face 77, the flange 80 turns the trigger clockwise to effect momentary closing of electric contacts I. Movement of the hand wheel 86 also effects, through a chain 87, movement of a pointer 85 co-operating with a fixed scale 116. Indicating pointers 91 and 94, geared to the spindle 59, also co-operate with the scale 116. The nozzle of the delivery hose 97 houses a piston valve 98, Fig. 6, which controls outlet ports 105 and the conical end of which is urged towards a conical seating ring 102 by a spring 100, the ring 102 being urged towards the valve by a spring 104. A part 109 of a control handle 110 is urged by a spring 112 towards engagement with a recess 108 in the valve. When the part 109 is withdrawn from the recess, the valve and ring take up a floating position such that, while the ports 105 remain closed, the pressure in the hose is reduced. The ports 105 are opened only when the pump is in action, the valve 98 being then moved away from the ring 102. The part 109 can enter the recess 108 only when the valve is in its floating position. Such entry, effected by the spring 112, serves to move the valve and ring further to the right, thus raising the pressure in the hose to a degree not less than the pumping pressure. A device 113, Fig. 5, responsive to the pressure in the hose, causes a switch B to be opened at the higher pressure and closed at the lower pressure. In use, the pointer 85 is set backwards by means of the wheel 86 to the desired position on the scale, the pointers 91 and 94 being at zero. The sleeve 73 is thus angularly positioned so that the angular distance of the pin 79 from the peak of the track 76 is exactly proportional to the amount of liquid to be delivered. As the nozzle is lifted from its hook, a master switch H, Fig. 8, is closed, and the motor may be started by momentarily depressing a button P. This energizes a relay S which closes the motor switch S1, a switch S2 in series with the contacts I and a relay T, and a switch S3 which maintains the relay S energized. On now raising the handle 110, the valve 98 assumes its floating position, with consequent closing of the switch B to energize the relay R, causing the catch 48 to release the fork 44. Under the action of the spring 32, the clutch members 29 and 60 engage and the pump and the shaft 59 are driven. The handle 110 is now released, so that the part 109 rides on' the valve 98. As pumping commences, the switch B opens to de-energize the relay R, and the sleeve 78 rises progressively until, when the predetermined quantity has been delivered, the pin 79 falls down the face 77 to cause momentary closing of the contacts I, producing energization of the relay T. The latter closes a switch T2, to maintain its energization, and a switch T1 to energize the relay C. The latter acts to disengage the member 29 from the wheel 26 and to engage it with the stop member 34, and also to disengage the member 60 from the wheel 58. A spring 63, Fig. 2, which has been stressed during rotation of member 60, now restores the indicating and setting mechanisms to zero position, determined by an adjustable stop. The valve returns to its floating position, energizing the relay R, but the part 109 of the handle 110 engages the recess 108 to produce a pressure increase which de-energizes the relay R. Time-responsive means act to de-energize the relay T and thus the relay C, the catch 48 maintaining the clutches disengaged.