GB876868A - Improvements relating to liquid dispensing apparatus - Google Patents

Abstract

876,868. Rotary pumps. COLOR CORPORATION OF AMERICA. Feb. 10, 1960 [Aug. 21, 1959], No. 4718/60. Class 110 (2). A rotary pump forming part of a liquid dispenser having a part-cylindrical discharge compartment 51, Fig. 3, communicating through an inlet 21 with a liquid supply hopper 12, comprises a vane 45 mounted on the axis of the compartment 51 and movable by an operating member 62 from an initial position in which liquid is allowed to flow into the compartment 51 to an intermediate position in which the vane isolates a sector of the compartment 51 and then through the compartment to expel the liquid through a valve controlled by movement of the vane, and an adjustable stop 64 limiting the movement of the vane. The valve comprises an annular duct 58 disposed in that part of the hub of the vane projecting forwardly of the latter and connecting the compartment 51 with a discharge channel 56 at the instant when the vane blade 47 contacts the surface 37 of the compartment 51. The vane is operated by a handle 62, the limit of movement of which, to adjust the quantity of liquid dispensed, is determined by the setting of an angularly adjustable stop'arm 64 in a notched plate 69, Fig. 2. Return movement of the vane after a dispensing operation produces suction within the chamber 51 so that any liquid trapped in the discharge channel 56 is drawn into the chamber 51 and, after the vane 45 becomes disengaged from the curved surface 37 but before it engages an oppositely disposed curved surface 38, an annular groove in the opposite end of the hub from the groove 58 connects the chamber 51. with the near side 55 of the vane and the trapped liquid is expelled into the chamber 51 dispersing any air bubbles trapped in the lower end of chamber 51. Liquid in the hopper 12 is agitated by a perforated plate 119 connected to a motordriven eccentric 116 or alternatively by a rotating paddle mounted in the supply duct 17 and projecting into the hopper 12. In a further embodiment, discharge is through a separate rotary plug valve 76, Fig. 11, which is so operated through a simple linkage system, by movement of the vane that, when the vane reaches the intermediate position, the valve is opened and the linkage broken, further movement of the vane then producing no further movement of the valve.