GB985494A - Improvements in viscosity gauges - Google Patents

Abstract

985,494. Viscosity comparators. F. L. GERIN. July 21,1961, No. 26612/61. Heading G1S. The apparatus is intended to compare the viscosity of a test liquid, e.g. engine oil, in a pressure circuit with a standard liquid. In the embodiment shown in Fig. 3 test oil under pressure enters the apparatus at 18 and passes into a lower chamber 46 where it enters hollow standards 38, 40 or a passage 41 and passes through orifices 42, 44 or a reducing valve 43 into an upper chamber 30, which houses a collapsible sac 36 containing standard fluid, and out through an outlet 20. Thus the fluid in the upper chamber is less than that in the lower chamber while test fluid under pressure is supplied to inlet 18 and the test fluid flowing past sac 36 equalizes the temperature of the test liquid and the standard liquid. The test fluid in the upper chamber 30 and the standard liquid in the sac 36 are connected by fittings 102, 108 with cylinders 34, 32 housing weights 48, 50 forming displaceable end walls to the cylinders 34, 32. Normally the pressure in the lower chamber 46 maintains the weights in the raised position and causes a valve 97 to obstruct orifice 42. When the pressure supply to inlet 18 is terminated valve 97 opens and test fluid passing through orifices 42, 44 start to equalize the pressure in the upper and lower chambers. The weights 48, 50 then fall drawing standard and test liquid respectively into cylinders 32, 34. The relative rates at which the weights fall are proportional to the viscosities. Nuts 52, 54 are provided on the weights 48, 50 and the quickest nut to fall touches a lever 51 and rotates it and its shaft 174 until the other nut engages the other end of the lever 51. Knife edges of the nuts are then forced into serrations on the lever 51 locking it at an inclination dependent on the relative viscosities of the liquids. This rotation of shaft 174 is transmitted to a pointer by a magnetic coupling. The sac 36 may be collapsed, Fig. 7, and the standard liquid replaced. Other embodiments are shown one, Fig. 26 having a container for the test fluid and a container for standard fluid formed with a common wall.