Patent GB-519112-A (GB)
Title: Apparatus for determining the viscosity of liquids
IPC: G01N11/06
Filed: 1938-06-15
Abstract: 519,112. Measuring viscosity of liquids. FIFER, A. J. J. June 15, 1938, Nos. 17845 and 21854. [Class 106 (ii)]  A sample of the liquid to be tested is delivered to a chamber and mechanical, electrical or electro - mechanical means influenced by the movement of the liquid during discharge used for comparing the time taken for the discharge of a predetermined volume of the liquid with the time taken by a similar volume of a standard liquid. The pulp, paint &c. is contained in a mixing chamber 1 from which a sample is allowed to flow into a testing chamber 9 through a valve 7 controlled by a solenoid 8. A baffle plate 10 divides the chamber 9 into comunicating filling and float sections 11, 12. An outlet valve 16 is actuated by a solenoid 17 through link 14 and a spring lever 18. The solenoid 17 also controls an overflow valve 21 to sump 25. Scavenging nozzles 44, 45, 46 controlled by a solenoid 34 supply water or the lighter constituent from a valve 33 to the chambers between each test. The float 13 is suspended by a wire 47 passing over the periphery of a disc 48 on spindle 27 to a balance weight 49. On the spindle 27 is an arm 52 which on counterclockwise rotation of the disc abuts against a fixed stop 53. The angular distance travelled by the arm 52 to stop 53 is equivalent to the fall of the float to its lowest position. On the disc is a segment 54 the length of which corresponds to the distance between marked levels 55, 56 of the float. The shaft 84 of a constant speed motor 83 supplied through circuit 105 from mains 128 drives through gears 85, 86, cams 88, 89. A sleeve 95 loose on the shaft has flanges 96, 97 between which is the fork of a lever 99 which when moved by a solenoid 102 engages clutch members 96, 94. When a tooth 110 on flange 97 engages a tooth 109 on a flange 108, a sleeve 107 is driven. The return of the sleeve 107 under the influence of weight 113 is prevented by a brake 111 operated by a solenoid 112. An indicator arm 115 is carried by a flange 114 of the sleeve 107 as well as a spring 116 which is adapted to move over a circle of fixed contacts 118 which may be adjustable as a whole relatively to compensate for temperature effects on the liquid measured. Operation. At the end of a complete cycle, all circuits except 105, 119 are broken, the chamber 9 is empty and has been scavenged, and the rod 59 is in the vertcal position, the float 13 being at its lowest position. The arm 52 is seated on the stop 53 and the motor is running, the sleeve 107 and the indicator being held in the position corresponding to the last completed test. All switches 122 . . . 127 are closed. The contacts 90, 91 are closed by cam 88. This opens the valve 7 and closes valve 16 and also turns valve 21 to its vertical position. The mixture flows into chamber 9 and the float rises. The disc 48 rotates clockwise and when the end 58 of the segment tilts switches 63, 64 to the left, the circuits 66, 119 are opened and 67 closed. The contact at spring 116 is interrupted and solenoid 112 is energized to release brake 111 and indicator. When the chamber 9 is filled, the position shown in Fig. 1 is reached and circuit 67 opened, solenoid 112 de-energized, brake 111 on and circuit 66 closed. The projection 68 presses contact springs 69, 71 together placing solenoid 73 across the live wire 74. The rod 75 is lifted and contacts 69, 71 maintained, the contacts 78, 79 being opened to de - energize solenoids 8, 17. The valve 7 closes and 21 is turned to position shown dotted. The solenoid 73 is kept energized until the cam 88 opens contacts 90, 91. When solenoid 17 is de-energized, the valve 16 opens and liquid is discharged. The float falls and disc 48 rotates counter-clockwise; and when end 57 tilts switches to right, the circuit 65 is closed and 66 opened together with 119. This is the start of the measuring cycle. The solenoid 102 is energized to clutch in the indicator. When mark 56 is reached, the end 58 releases switch lever 59 and circuit 65 is broken and sleeve 95 unclutched. Shortly afterwards, the cam 88 opens contacts 90, 91 and thus circuit 74 de-energizing solenoid 73, making contacts 78, 79, and releasing contacts 69, 71. The solenoids 8, 17 cannot be reenergized until the next cycle. The fluid flows into sump 25. The valve 28 is opened by hand and the contents returned to the mill circuit. When cam 88 closes contacts 92, 93 prior to the next cycle, the circuit 35 is made and solenoid 34 energized to scavenge, the scavenging liquid being diverted by valve 26 into sump 31. A simplified circuit is described where the liquid is such that a complete discharge of the fluid in chamber 9 is possible.