Patent GB-767279-A (GB)
Title: Liquid dispensing apparatus
Inventor: STINER STEWART
IPC: B01F13/10
Filed: 1954-02-06
Abstract: 767,279. Dispensing liquids. STANDARDTOCH CHEMICALS, Inc. Feb. 6, 1954, No. 3540/54. Class 116. Tanks 20, Fig. 2, are moved to position a selected tank to deliver to a container 103 through a positive displacement pump 25 until a selected volume of liquid has been delivered. In the machine illustrated the pumps 20 are arranged in annular form about a hollow shaft 131 by which they are rotated to position the selected tank for delivery. The tanks contain pigments carried by a suitable liquid vehicle to be mixed with white paint in the container 103 and the machine may be set to deliver selected volumes of several selected pigments in succession. The pigments are delivered by gear pumps 25 rotated through pinions 28, 29 from a central shaft 37. When the machine is not in use the containers revolve continuously while the shaft 37 is stationary so that the pumps 25 withdraw liquid from the tanks and return it through two-way valves 32 either to a pipe which returns the liquid above the surface of the liquid in the tanks or to a submerged pipe provided with jets for stirring the liquid. When liquid is to be delivered from a selected tank the shaft 131 is stopped with the selected tank above the container 103. In this position a solenoid 130 common to all the tanks may depress a plunger 136 on the valve 32 so that the pump 25, which is now driven through the gears 28, 29 from the shaft 37, delivers the liquid to a nozzle 148. The nozzle 148 has the section indicated in Fig. 14 to prevent drips when delivery is complete. The delivery is metered by pulses transmitted by switches operated by cams on the shaft 37 and transmitting pulses to counters which terminate delivery when the volume indicated by manually controlled switches associated with them has been delivered. The colours of the pigments to be delivered are set by three manually operated switches 77, 78, 79, Fig. 8, and, when the corresponding quantities have been set on switches associated with the counters 80, 81, 82 and the size of the container 103 has been set on a switch 83 a switch 71 is set to connect A.C. supply to each of two conductors 74, 76 and a selflocking switch 87 is closed. The conductor 74 supplies operating current to the motor 48 which rotates the tanks until a switch 90 is closed by a cam on the shaft 131 to indicate that the tank selected by the switch 77 is in position for delivery. This completes a circuit over a multi-conductor cable 93 and the selected contact of switch 77 and over normally closed contacts 95, 99 to a solenoid 63. The solenoid 61 pulls a link 53, Fig. 5, mounted by a slot 54 on the driving spindle of the shaft 131, radially outwards against the bias of a spring so that a stop 57 on it is engaged by a stop 52 on a disc 46 rotating with the shaft 131. The link 53 is thus swung clockwise in Fig. 5 with the shaft 131 against a pneumatic damper 65 until it operates switches 66, 67. The switch 67, Fig. 8, opens the circuit of the motor 48 so that shaft 131 and the tanks are held against rotation, with the selected tank in position for delivery, by the links 53 and by spring biased friction pawls 104, Fig. 2, which prevent reverse rotation. The switch 66 closes a circuit to four switches 108, 109, 110, 111 operated by cams 112, 113 on the common shaft 37, Fig. 2, operating the pumps. At a predetermined position of this shaft the switch 108 transmits a pulse over a conductor 115 and over normally closed contacts 117, 120 to a terminal S of the counter 80 to prepare this for counting pulses applied to a terminal C. Pulses are then transmitted to this terminal by the switch 109, by the switch 111 or by both the switches 110 and 111 according to whether the switch 83 is set to indicate the capacity of the container 103 as a gallon, a quart or a pint. The counter 80 comprises the timing device of U.S.A. Specification 2,175,865 with the synchronous motor replaced by a magnet-operated stepping ratchet. As soon as the starting pulse is applied to terminal S the counter closes contacts energising a terminal 2 connected to the solenoid 127 which operates the valve 32, Fig. 2, to deliver liquid to the container. The terminal 2 remains energised to continue delivery until the number of pulses corresponding to the pre-set volume has been applied to the terminal C after which the terminal 2 is de-energised and a terminal 1 is energised. The terminal 1 operates a relay 97 which disconnects the switch 77 and connects in the switch 78 indicating the next pigment to be delivered. This causes the solenoid 61 to release so that the tanks again revolve until the tank selected by the switch 78 is in position to deliver. Delivery from this tank then takes place under the control of the second counter 81 which ultimately transfers control to the third switch 79 and the third counter 82 which, when the pre-set volume of the third pigment has been delivered, operates a solenoid 88 to release the switch 87 so releasing the apparatus for further operation. The switch 71 has two further positions in one of which it provides current to rotate the tanks 20 for display and cause the pumps 25 to agitate the liquid as described above, and in the other of which the machine is entirely switched off. In a further embodiment a fourth counter is provided which is manually set to cause delivery of a quantity of white paint to complete the filling of the container. In still a further embodiment delivery of the pigments selected is automatically followed by delivery of white paint until a weighing device on which the container 103 stands indicates that the container is full. Audible or visual warnings operated by floats indicate when any of the tanks is empty.