Patent GB-767269-A (GB)
Title: Improvements in or relating to mixing machines for dispensing liquids
IPC: B01F15/04
Filed: 1954-08-13
Abstract: <PICT:0767269/III/1> <PICT:0767269/III/2> <PICT:0767269/III/3> <PICT:0767269/III/4> <PICT:0767269/III/5> <PICT:0767269/III/6> <PICT:0767269/III/7> <PICT:0767269/III/8> A method of producing and dispensing coours comprises simultaneously metering various quantities of a variety of liquid colourants from a number of storage tanks to a central delivery control point and simultaneously delivering from the control point pre-selected ones of said metered liquids while re-circulating others of the liquid colourants from the control point back to and through the storage tanks to agitate and maintain uniformity of the liquid dispersion of colourants stored therein.  The machine Fig. 1, comprises a frame 1 supporting detachable paint tanks 2 each provided with an orifice for discharge of paint and an orifice for return of paint to the tank.  An electric motor 57 through gearing and a clutch provides oscillatory motion for a crankshaft 25 the movement of which is utilized for supply of paint from selected tanks 2 to a container 12.  A dial 100 is provided the setting of which determines the number of oscillations of the shaft 25.  For each paint tank 2 there is a dial 34 mounted on the shaft 25, the setting of the dial determining how much paint is withdrawn from the associated tank at each oscillation of the shaft.  In each tank 2, Fig. 15, the discharge orifice 6 is associated with a cylinder head valve body 7 and the return orifice 8 is connected by a pipe 9 to a valve block in turn connected by a pipe 11 to the valve body 7.  The body supports a cylinder 13 containing a piston 16 which is operated by means of a rod 17 and a yoke 18 connected by a spring 21, Figs. 2 and 5, to a rocking beam 20 freely rotatable about the shaft 25.  The dials 34 can be keyed to the shaft 25 by clamping arms 37 provided with indicators 41.  Each dial can be locked by upward movement of a locking lever 35 and may then be set to a calibrated position and relocked, the position determining the amount of lost motion of the crankshaft 25 before contact of dial stop 43 with stop 46 of rocking beam 20 takes place and also determining the stroke imparted to the piston 16.  Upon clockwise angular movement of the shaft 25, angular movement is imparted to the dials 34, dial stops 43, rocking beam stops 46, rocking beams 20 yokes 18 and rods 17, Fig. 15 causing intake of colourant by the piston 16 until the intake stroke is completed, the pistons having been brought into communication with the tank orifices 6 by movement of valves 280 by oscillating rods 285.  On return movement of the crank-shaft 25 the pistons 16 deliver colourant to cylindrical valve heads 7 conduits 11 and a central valve block, the valves 280 having opened communication between the pistons and the conduits 11.  The valve block 10, Figs. 6 and 9 is formed with cylinders 225 and valves 220 corresponding to the number of dials 34.  The valve block has a rod 230 on which is slidable a tube 229 carrying a valve lift plate 218.  Anvil collar plates 233, 234 each fitted with facing leather washers are fixed to the tube 229, confining movement of a hammer 210.  The opening and closing of selected valves 220 are effected by blows of the hammer. When the hammer strikes anvil plate 233 all the valves 220 which are engaged by the tips 217 of rods 215 are lifted with the valve plate 218 and the asociated ports 274 are opened instantly allowing paint to be forced by the pistons 16 through the conduits 11 to the container 12.  When the hammer strikes anvil plate 234 the selected valves 220 close the ports 274 instantly and the colourants circulate back through pipes 11, 9 to the storage vessels 2.  The engagement of the tips 217 of rods 215 with the valves 220 depends upon the position of a control knob capable of three positions "Delivery," "Standby" and "Continuous circulate."  In the "Delivery" position, engagement takes place between the tips and those valves 220 associated with selected dials 34 which are set to deliver not more than 1,000 units of liquid (corresponding to full stroke travel of the pistons 16), the rods being urged into engagement by springs 222. Other dials are set to deliver more than 1,000 units and in this case pins on the dials act at the end of their movement to withdraw the rod from the valves, against the action of the springs 222.  When the control knob indicates "Standby" or "Continuous circulate" all the rods are held immobilized away from the valves 220, so that the colourants are circulated though the storage vesels and the valve block 10, either at intervals on periodic activation of the machine clutch ("Standby") or through continuous pumping of the pistons 16 ("Continuous circulate").  A vapour lung may be provided connected to the top of the storage tanks and containing volatile anti-skinning agents which pass over to the tanks as liquid is withdrawn therefrom. The container 12 for the mixed liquids is placed on a plate 101, Fig. 13, which is mounted on a vertical notched shaft 102 journalled and pinned in a sliding frame base 103.  A knife 144 pivoted at 143 and provided with a control knob can engage in any one of the notches 145, 146, 147, for adjustment of the height of the can, springs 149, 150 tending to raise the base 103 along guides when the knife is released.  As the base 103 is raised it engages the end of a lever 112, the other end of which terminates in a pawl 118 engaging cam ratchet 115 keyed to shaft 117 along with ratchet wheel 116.  A control dial 100, Fig. 1, is keyed to shaft 117, the degree of movement of which is limited by stops 131, 132, 133 of cam ratchet 115, by the blocking action of pawl 118, according to the can size setting.  The dial is turned anticlockwise to produce a number of clicks of a pawl 140 against ratchet wheel 116, the clicks corresponding to the number of oscillations of the crank-shaft 25. Each tooth of ratchet 116 corresponds to the engagement of clutch 70, Fig. 11, for one complete revolution of timing gear assembly 85 and one complete cycle of movement of the pistons 16.  Assuming that the dial 100 is set to move two teeth of ratchet wheel 116, then the motor 57 is started by means of a starter button.  During the first revolution of the gear assembly 85 a rollpin 170, Fig. 11, engages cam arm 173 whereby through rod 175 lever 180, link 182 and rotary linkage the rod 183, Fig. 13, and lever 165 are raised causing the pawl 166 to rotate ratchet 115 clockwise one tooth.  During the second rotation cam tooth 122 acts to raise lever 163 whereby a switch is opened to cause disengagement of the clutch 70 and stop further movement of the gear assembly 85.  The machine is controlled electrically, a timer motor being provided for use when the control knob is set at "Standby." This setting is for use when the machine operator is not to be present for a restricted period, providing a programme of on-and-off operation ensuring uniformity of colour dispersion at all times.  The engagement of the clutch 70 is controlled electromagnetically.  The metering pump and dispersing valve constructions are respectively described in Specifications 753,417 [Group XXVIII] and 767,270.