Patent GB-767280-A (GB)
Title: Liquid dispensing apparatus
IPC: B01F15/04
Filed: 1954-03-22
Abstract: 767,280. Control of several motors. STANDARD-TOCH CHEMICALS, Inc. March 22, 1954 [Oct. 27, 1953], No. 8250/54. Class 38(3) Also in Group XVIII] A liquid dispensing apparatus comprises a number of reservoirs for liquids selectively dispensed into a container, a selective positioning device, a positive liquid displacement pump, a metering device which controls the dispensing during operation of the pump and an electric motor for producing relative movement between the reservoirs and container to bring the container and the particular reservoir into dispensing position with respect to each other and the provision of a braking device for abruptly stopping operation of the motor when the particular reservoir and container are correctly positioned for dispensing. The dispensing apparatus which is an improvement of that described in Specification 767,279 [Group XVIII] comprises a series of containers 24 mounted by a frame 26 on a hollow shaft 25 journalled in a column 22 on a base 20. Within the shaft 25 is a driven shaft 27 carrying an upper pinion 28 driving a series of pumps 31. The shaft 27 is driven by a motor 50; the shaft 25 is driven by a motor 55 through 58 and gear 59 having a bracket 63 to engage an arm 61 on a sleeve 62 integral with the shaft 25. A tension spring between the arm and gear 59 permits the shaft to overtravel and limits the shock of stopping. A dispensing valve 33 beneath each pump has a spring- urged plunger 36 actuated by the end 37 of a master control lever 38 pivoted at 39 and actuated by a solenoid 40. Liquid is dispensed at outlet 41. When the motor 55 is operating the liquid circulates in a closed path through outlet pipe 43 and inlet pipe 44. The gear 59 carries a switch contact 71 arranged to contact a series of container positioning switches 72. A commutator 74 is secured to the shaft 27. The commutator, Fig. 11, comprises an outer contact ring 75 with an inward projection 76. A brush holder 77 has two circuit brushes 78, 79 engaging the projection and ring respectively. The holder has four counting circuit brushes 80 to 83 for determining the quantity. A ring 84 engages one brush 80; the ring has eight projections. the longest 85 being for gallons contacts the brush once per revolution of the shaft 27, three projections 86 and projection 85 contact brushes 82, 83 four times for quarts and all the projections 85 to 87 contact the brushes eight times for pints. Three container switches 88 to 90 on the column 22 are selectively closed by the containers. To agitate the liquid a stationary pinion 94 meshing with a gear 95 are mounted on the frame 26. The shaft of the gear 95 has a gear 97 around which passes a chain which also passes round twelve pinions 99 on a shaft 100 with paddle arms 101 so that rotation of the frame drives the paddle. For greater agitation the shaft 100 drives a second shaft with paddles 109. Alternatively the shaft 100 has helical grooves whereby a nut supporting a wire mesh and having two cam followers engaging the grooves is reciprocated. Power is supplied to a switch 122 with positions Off, Display, Dispense. When at Dispense the output of rectifier 125 energizes the motor 55 which rotates the containers, recirculates and agitates the liquid and a half wave rectifier 132 energizes the dispensing control circuits. The relay 136 operates an intermittent signal 139 in series with a switch 140 operated by a cam shoe 141 on sprocket wheel 52 driven by pump motor 50. Energizing the winding of the relay silences the signal and energizes the dispensing circuits. The liquids are selected on dials for colour by switches 146 to 148 and for quantity by switches 153 to 155. The switches 72 are represented by a switch 159. A pint container is positioned under outlet engaging the arm 93 of the switch 90 which is connected to start button 176 which is pressed to commence dispensing. The contact 71 on the sprocket 59 engages a stud of the reservoir switch 72 selected by the switch 146 and indicated by the switch 159. The circuit is completed to the arm 178 of the switch 146 to stop the motor 55. A delay allows time for the operation of the shock absorber. When the brush 78 engages the projection 76 of the commutator the solenoid 40 is operated to open a dispensing valve and dispensing commences for two pints say. When projection 85 disengages brush 81, the brush 164 advances to the first terminal when the brush 81 disengages the next projection 87 the brush 164 advances to the second terminal closing the circuit with the switch 153 and re-energizing the motor 55. The solenoid 40 is de-energized stopping delivery. The arm 160 of the switch 159 rotates to the position for the second colour to be delivered selected by switch 147, and the switch 163 returns at high speed to normal; all circuits return to normal before recommencing delivery. The second colour is then dispensed. When the arm 160 of the switch 159 contacts terminal 161, the containers stop and dispensing ceases; the motor 55 restarts and switch 163 resets to normal. The third dispensing then takes place to complete the operation. The valve control may be replaced by a solenoid valve for each container. In a modification the time delay circuits are omitted and the reservoirs stop only when the contacts of the desired reservoir positioning switch 72 have first closed and then opened. Means are provided for starting the pump motor for high speed action for a predetermined minimum time before dispensing commences when the container is placed in position and if dispensing does not commence within a predetermined time the pump motor is stopped. To keep the liquids agitated the reservoir drive motor is operated periodically. A timing device such as a thermal relay 314, Fig. 17, may be used; having a heater winding 315 connected to pump motor 50 and contacts 317, 318, the latter being carried by a metallic arm 319 heated by heater 315. After setting the switches the start button is pressed and relay 321 operates and when contacts 317, 318 close the dispensing circuits are energized. To prevent the motor 50 operating continuously if the start button is not pressed, a recycling timer 326 is provided which closes its contacts 327, 328 after the terminals 329, 330 have been energized for a predetermined time interval so operating the operation terminating relay 332. Relay 309 is operated releasing relay 306 and the motors 50, 55 are de-energized. To ensure agitation of the liquids if they are left undisturbed for some time a small timing motor 339 is provided which drives a cam 340 which periodically closes contacts 341, 342 to energize rectifier 125 and operate motor 5,5 to drive the pumps at slow speed, the contacts may be short circuited if the motor 55 is required to operate continuously.