GB255136A - Improvements in pumps for dispensing petrol oil and the like - Google Patents

Abstract

255,136. Jevons, W. H. April 9, 1925. Rack-and-pinion actuated pumps; stroke, varying; measuring-devices.-A pump for delivering predetermined quantities of petrol &c. is actuated by rack-and-pinion K and has a coin-freed mechanism controlling the operation of the rack. An adjustable sfop k on the rack determines the stroke of the rack. The spindle of the pinion a is in two parts A. A<1> connected by a clutch a<1> and extends through the casing C to carry an operating crank A<3>. A sliding clutch B is keyed on the spindle A<1> and may be moved into engagement with either of two fixed clutches B<1>, B<2>. of which the clutch B<1> prevents forward rotation of the pinion for operating the pump on the delivery stroke, and the clutch B<2> prevents rotation in the opposite direction. The clutch B is moved by two arms D fixed to a rocking spindle D<1> operated by a pair of toggle-levers E, E<1> connected by a spring e which moves them over the dead centre. The lever E is connected by a pin e<1> to the lower end of a lever F loosely mounted on the spindle D<1> and adapted to be moved by a push rod g carrying a bar G with a slot g<1> to receive the coin from a shoot H'. When the bar is pushed in, the top of the coin engages the lever F and swings it over, thereby moving the lever E until the spring e reverses the lever E<1>. The end of the lever E<1> engages a pin e<3> on an arm F<1> fixed to the shaft D<1>, so that the shaft is rocked to move the clutch into engagement with the clutch B<2>. The shaft A<1> can then be rotated to deliver the liquid until the stop k engages a bell-crank lever L, which operates a lever M to reverse the levers E, E<1> and restore the mechanism to its initial position. The spindle A<1> is then rotated in the opposite direction to return the pump plunger to its bottom position. When the plunger reaches this position, the rack operates a lever Q<1> to raise a rod Q against the action of a spring q and thereby withdraw from the coin slot a rod p which prevents a coin from entering the slot until the pump plunger is at the bottom position. In another form, the lever F is returned by a screw and nut operated through gearing by the crank A<3>. An arm N fixed to the spindle D<1> may be operated by an attendant to bring the clutch B into neutral position when it is desired to cut out the coinfreed mechanism.