Patent GB-657146-A (GB)
Title: Improvements in or relating to liquid measuring and dispensing apparatus
IPC: B67D7/30
Filed: 1948-12-13
Abstract: 657,146. Petrol dispensing pumps. AVERY-HARDOLL, Ltd., and FRASER, J. Dec. 13, 1948, No. 32194. [Class 102(i)] [Also in Group XVIII] Relates to meter pumps which, before delivery of liquid, can be set so that when the required quantity has been delivered the flow is stopped by the closing of a valve between the meter and the delivery nozzle, closing 'the valve and switching off the pump motor being effected by mechanism driven by the meter and controlled as to its time of operation by a settable member which is returned to its initial position by the movement of the meter; and comprises a floating lever acted on by the starting control and connected to the cut-off valve and motor switch, the settable member, when displaced from zero position, co-operating with the floating lever to hold a point thereon against displacement and thereby provide a fulcrum about which the floating lever is moved by displacement of the starting control to open the cut-off valve and close the motor switch, the return of the settable member to zero position releasing the floating lever to permit closure of the cut-off valve and opening of the motor switch whilst the starting control remains in the starting position. General arrangement (Fig. 2).-One end of the floating lever 50 is connected by a rod 51 to the cut-off valve 94 and the motor switch (not shown) and the other end is pivoted to a member 48 which can co-operate with the driven member 39 (i.e. the " settable member ") of a clutch whose driving member 38 has teeth 37 engaged by a worm 36 on a shaft 28, Fig. 1, driven from the meter. The floating lever is held up by a spring 63 at one end and a spring 72 at the other end, the spring 63 being stronger than the spring 72. When the settable member 39 is at'zero a hole 65 in it is opposite a peg on the member 48, which is slidable on studs 68, 69. A flat surface 57 on the floating lever 50 co-operates with a roller 58 on the starting control member 59 rocking about a centre 62. Indicating mechanism (Fig. 1). - A fractions drum 10 rotates with a shaft 13, and drums 11, 12, freely mounted on the same shaft, are driven at a slower speed through gearing from the common shaft 13. The meter drives a shaft 27 and from thence the indicating mechanism is driven through bevel pinions 25, 26 and a gear train incorporating a unidirectional clutch 34 and a friction clutch 35. the bevel pinion 26 being mounted on the shaft 28. The shaft 13 carries a cam 75 which, except when the drum 10 is in the zero position, limits inward movement of a pawl 74 on an arm 73 pivoted on the stud 68, Fig. 2, and controlled by a spring 78. The arm 73 has on it a projection 76 which lies in the path of a nose 77 on the member 48 and so prevents full downward movement of that member unless the drum 10 is in its zero position. Two discs 86, 87 rotate respectively with the shaft 13 and the drum 12 and have notches 85 which come into line when the drums are in the zero position and so allow a nose 83 on a lever 84 to enter them, the movement of the lever 84 moving away a latch 79 so that the starting control member 59 may be moved counter-clockwise (as seen in Fig. 2), to switch on the pump motor. The drums are zeroized by a knob 88 which is connected to the common shaft 13 through a clutch 89 when the starting control member 59 is in the " off " position, the clutch being disengaged by a ramp 92 on the member 59 when the latter is moved to the " on " position. When the member 59 is moved to the " off " position a second ramp on it 93 disengages the gear train between the shaft 27 and the common shaft 13. Pre-setting mechanism. - The settable member 39, which is normally held disengaged from its driving member 38 by a spring 47, carries markings to represent quantities of liquid to be delivered and can be set, when disengaged, by a knob 46 which rotates its spindle 40 through a bevel gear train 45. A notched disc 41 on the spindle of the knob 46 co-operates with a roller 41a mounted on an arm 43 and urged against the edge of the disc by a spring 44, the arrangement being such that the roller locates the settable member accurately with any of the figures thereon opposite the index. Cut-off valve (Fig. 2A).-The cut-off valve 94 is between the meter outlet passage 97 and the delivery passage 102, and comprises a fixed sleeve 96 which opens at one end into the opening 97 and at the other end into a closed chamber 98 and has ports 99 leading to the passage 102, a movable sleeve 104 and a mushroom head 103 which seats, when the valve is closed, on the inlet end of the fixed sleeve 96. The valve is opened against a spring 113 by a bell-crank lever 56 on one arm of which is pivoted a sliding collar 55 which co-operates with a collar 54 on the rod 51. Ports 105, 106 in the sleeve 104 provide a free passage when the valve is open and a small port 107 in the sleeve' 104 permits a restricted flow when the valve is partly closed. The first part of the closing movement of the valve is damped by a disc 108 which tends to trap liquid, this damping movement being nullified after the first closing movement by a leakage path 112. Operation.-The drums 10, 11 and 12 are turned to zero by the knob 88 and the member 39 is set by means of the knob 48 to the quantity of liquid required to be delivered. The starting control member 59 is moved from the position shown in Fig. 2 counterclockwise, causing the roller 58 to depress the floating lever 50 against the pull of the springs 63, 72. Since the spring 72 is the weaker the peg member 48 first presses down on the settable member 39 and engages it with the driving member 38, and then the rod 51 descends and closes the motor switch and opens the cut-off valve 94. As liquid flows the rotation of the meter causes the member 39 to turn back to its zero position, at which the hole 65 comes into line with the peg member 48 and the peg enters the hole through rocking of the 1ioating lever 50 about the roller 58 under the influence of the spring 63. The other end of the floating lever rises, bringing with it the rod 51 far enough to partly close the cut-off valve which thus allows a restricted flow. The partial closing is due to the fractions drum 10 not reading zero and full downward movement of the peg member 48 thus being prevented. Delivery continues at the reduced rate until the drum 10 reaches its zero position, when the member 48 completes its downward movement and so allows the spring 63 to raise the rod 51 until it has completely closed the cut-off valve and opened the motor switch to stop the motor, Specifications 426,267 and 626,590, [both in Group XVIII], are referred to.