US2574359A - Viscosity tester - Google Patents

Description

Nov. 6, 1951 A. G. THOMAS VISCOSITY TESTER 2 SHEETS-SHEET 1 Filed Nov. 15, 1945 T m 5 m R M T 7 4 Nov. 6, 1951 A. G. THOMAS VISCOSITY TESTER 2 Sl-IEETSSl-1EET 2 Filed Nov. 15, 1945 FIG. 2

INVENTOR. MM

' glass or other transparent viscosity tube Valve 15 may be cemented or otherwise fastened to arm l and may consist of synthetic rubber or Patented Nov. 6, 1951 VISCOSITY TESTER Albert Thomas, Alexandria, Va.,1assignor to Industrial Research Institute, University of Chattanooga, .Hamilton County, Tenn.

ApplicationNovemb'er 15, 1945, Serial No. 628,783 3 Claims. (01. 73-55) This invention relates to testers generally, and especially to oil testers for determining'whether crankcase oil in motor vehicles is fit'for further use, or not.

In operating motor vehicles, it is customary to change crankcase oil after a period of usage. This is ordinarily determinedon a mileage basis. For motor cars, it has been a widespread practice to change oil after 1,000 miles of driving, more or less.

Anotherobject is to provide a tester of greater accuracy by incorporation of means for automatically determining, in effect, the viscosity index of any oil tested.

A further object is to provide a simplifiedrtiming device for actuation of the oil cup valve, or for other purposes.

An additional object is to provide a simplified mixing chamber for oil and diluent before it passes over a screen for a dirt test.

Other objects will appearin the specification.

In the drawings:

Figure 1 is a front elevation, with casing in section, of a simplified oil testerin which various parts are combined to serve several functions.

Figure 2 is a top plan view, with top cover partly-broken away, showingthe timing device,

hinged cap, and mixing elements of the tester of Figure 1.

Figure 3a shows an edge view of a spring catch. Figure 3 is a front elevation showing another form oftiining device anda special viscosity cup and associated mechanism for eifectively compensating viscosity determinations for variable viscosity indices of oils under test.

Figure 4. is a. fragmentary elevation of a viscosity cup with two needle valves attached to one operating arm.

In Figure 1, casing I is'fastened to cross plate 2 and short plate 3 isscrewed to casing l. Top

cover 6, having openings for rods 5 and 6 and ,for funnel i with cap 8 pivoted at 9 to a lug on the cover, is provided and may be detachable.

Rods 5 and ii are provided with top buttons Ill and 1!. Cam 12, attached to cap 8, is positioned toengage pin i3 on red 5 to lift this rod when the cap is swung about pivot 9.

Rod 5 may be of rectangular cross section, to

ing resilient valve 18 below the bottom end of IT.

other material not easily affected by oils. Spring l8, surrounds rod 5 and is underslight compression between plate 3 and arm so that it assistsgravi-ty in normally keeping valve I5 below the end of tube ll. This tube is .heldin position by clamp 19 on plate 3 and by openings in plate 2 and the bottom 20 of overflow trough 2| which may be screwed to plate 2. A packing gland may be provided to prevent leakage around the upper end of tube ll.

Piston 22, which may include a leather washer, is fastened to the lower end of rod 5 and-is vertically movable in cylinder 23 fastened in tank 2 through its bottom. This tank is for the purpose of holding diluent or cleaning fluid which may be kerosene if desired. It is attached to casing l or to suitable framework by means of lugs 25.

Opening 26 in cylinder 23allows fluid to fill the cylinder when the piston is in the lifted position shown.

Tube 27 leads into the lower part of cylinder 23 and carries fluid to nozzle28toclean tube I], to tube 55 for photocell unit 29 to clean this unit, to mixing buckettil through nozzle 32 and to cup 3! through a nozzle onthe rear side of nozzle 32.

Viscosity cup v3| is preferably of thin metal or of materialof poor heat conductivity so that excessive heat will not be taken from the oil or other fluid under test. It is fastened to trough 2!, preferably through heat insulation material if the trough is of metal. The cup has zcentral metering tube 33 screwed into an opening. This tube extends inside the cupfor a vertical distance which'may be about one fourth the height of the cup. Drain opening 34 is also provided in the bottom of thecup and is adapted to be closed by synthetic rubber valve'35 attached to flexible arm 36 which is fastened to collar 31 verticallyslidable on rod 5 above supporting pin 38 on the rod. A suitable slotcan be cut inplate 2 to allow pin 38 to passthrough when rod 5 is depressed. Needle valve 130, pivoted to arm 4| at 39, normally rests against the top of tube 33 to close it, a suitable guide being provided.

Bucket 3S issupported by attachedpivotpins 42 resting in suitable slots in the side Walls of trough 2| (Figure 2), and by pin attached to the trough. Spiral spring 44, attached to the trough and to a pin 42, may be used to hold bucket 30 normally against pin 43.

Trough ,2! has inner wall 45the top edge of which is'below pivots 42 so that fluid from bucket 30 will drain out of the bucket into'compartment if when bucket 301s rotated in clockwise direc- 'tion by-being struck with the lower end of ,startfir rod 6. This rod is vertically slidable in-guidedl attached to cover 4. Tension spring 48, attached to guide 6'! and rod 6, normally holds the rod in the position shown, a suitable stop being provided. Arm 4.), with attached cam 5.0, is attached to rod 5 and extends over so that it will strike 3 release 5| of timing device 52 pivoted at 5la, when rod 6 is depressed.

Trough 2| is extended as shown, to catch drainage from cup 3| and has attached drain pipe 53 to direct this fluid into can 54 resting on the bottom plate 55 of the casing. Similarly, drainage from tube I! will fall into can 54.

Coiled tube 56 leads into compartment 45 and is connected into photocell unit 29 so that it will conduct the mixture of diluent and oil or other fluid from double compartment bucket to screen 51 of relatively fine mesh. The two cornpartments 30a and 36b of bucket 39 are formed by partition 360 (Fig. 2).

Photocell or dirt-testing unit 29 comprises transparent glass or plastic cylinder 58 containing photoelectric cell 59 pressed against transparent wall 59 by threaded plug 6| through which conductors 52 may be passed to be connected to cell 60. These conductors are connected with electrical instrument 63 which may be a microammeter or milliammeter. Unit 29 may be supported by a bracket or by the connected tubes.

Screen 51 is supported on drain pipe 64 passing through the cylinder wall and upon pipe or tube tube 65 connected with tube 21 andalso passing through the cylinder wall. Additional supports for the screen may be provided and it is preferable to provide another drain, connected with tube 64 and entering the cyllinder above screen 51. This screen may be slotted near its lower end.

Electric lamp 66 is attached to reflector 61 which is fastened to transparent top plate 69 which is screwed to the top edge of the cylinder 58.

Funnel l is suitably fastened and has attached copper or other metal coil 69 the end of which is positioned to drop fluid from funnel 1 into cup 3|. This coil is suitably insulated and is wound with heating wire 79 which may be supplied with current through the terminals shown, including thermostat Stem 12 of dial type thermometer 13 is placed in cup 3| to indicate the temperature of the fluid under test. This thermometer and instrument 63 are supported by the front casing.

Arm 9| is pivoted to vertical plate M of the timing device at 15. This plate is integral with horizontal base platelB. Spring strip H, with r a projecting edge adapted to rest upon shelf 18 attached to plate 14, is fastened to arm 4| (see Fig. 3a) The lower end of this strip is struck by cam 19, attached to pulley 80, when weight 8| fastened to cord 82 passing around the pulley, is

allowed to fall and so to rotate the pulley and coaxial gear 83, by means of ratchet 84 on an edge of the pulley striking notches in the face of gear 33. Rod 85 extends outwardly and is bent at the rear and attached to the face of pulley 38. This arm is adapted to be struck by arm 86 attached to rod 5 when the rod is depressed.

Knob 81 has attached pointer 89 and is manually rotatable on shaft 88 which is rotatably fastened to plate 14'. This shaft supports knob 81 and gear 83. A suitable friction device such as a resilient strip, is fastened to knob 81 and presses against shaft 88 so that the knob may be manually adjusted in angular position on the shaft but the shaft will rotate the knob and arm 89 in counterclockwise direction (Fig. 1) when weight 8| is allowed to fall slowly.

Gear 83 drives escapement 90, pivoted to plate 14, by means of toothed wheel 9| which in turn is driven by gear train 92 having suitable bear- 4 ing on shafts fastened to plate 14. The escapement regulates the rate of fall of weight 8| and therefore the rate of rotation of pulley 80.

Arm 89 is bent so that it will strike resilient strip 11 and force it off the supporting shelf 18, when arm 89 is rotated in counter-clockwise direction past the strip.

The circuit to lamp 65, and to any other lamps which may be used to illuminate the device, is controlled by toggle switch 93 mounted on the casing or any convenient support. When starter rod 6 is depressed, cam 58 on arm 49 strikes the arm of switch 93 and forces it to the left to close the circuit. When clearing rod 5 is depressed, cam 94 on this rod strikes the switch arm and forces it to the right to open the switch.

The heating circuit including resistor 10 may be provided with a suitable switch. This switch would ordinarily remain closed when it is desired to use the tester so that the coil 69 will be warmed and cup 3| will be maintained at a moderate temperature.

In operation, cap 8 is lifted, which results in valves 35 and I6 closing the drain opening of cup 3| and the bottom of tube ll, respectively, since cam I2 strikes pin |3 and lifts rod 5 as the cap is rotated. The rod is held in the lifted or up position by spring 96, fastened to plate 2, pressing against groove 9'! in the rod. Then a small sample of oil, say, is placed in funnel 1, from which it flows through tube 69 and becomes heated. Cap 8 is then closed. The heated oil drops into cup 3| and flows over attached lip 95 and into compartment 30a of bucket 30. The overflow from this bucket spills over the lower bucket edge and into trough 2| from which it passes through tube 53 to can 54. Bucket compartment 301) is normally filled with diluent from nozzle or tube 32, when rod 5 is depressed to clear the mechanism and to actuate pump piston 22.

After thermometer 13 reaches a steady indication, the temperature of the oil is read and arm 89 is rotated relative to a calibrated temperature scale (not shown) until the arm, or pointer, is in register with the temperature mark on the scale equivalent to the reading of the thermometer. Button H is then pushed down to depress starter rod 6. This causes arm 49 to strike one end of pivoted catch 5| so that it lifts its attached pin from gear 92a, and weight 8| accordingly starts to fall with the result that cam 19 quickly lifts strip 11 and arm 4| so that needle valve 40 is raised and oil starts to flow through orifice or metering tube 33. Bent strip 11 will remain in elevated position on shelf 18 until arm 89, rotated by the weight in counterclockwise direction, strikes it and knocks it off the shelf, the resiliency of the arm making this possible. The weight of the arm, or a spring if desired, will then force needle valve 40 down against the comically reamed upper end of tube 33 to close the orifice and so to stop flow of the oil.

The time interval between the opening of the valve by cam 19 and its closing by arm 89 will depend upon the angular position of the latter arm, since escapement causes the weight to rotate the gears at uniform rate. The friction between knob 89 and shaft 88 is sufficient to prevent slippage when arm 89 strikes strip 11 but not enough to prevent setting of the arm relative to the temperature scale. The scale is callbratecl so that the hotter the oil, the less time will valve 49 remain lifted so that viscosity variation due to temperature can be compensated for interstices.

by changing the time interval of-fiow through the orifice.

The oil builds up in tube I! to heights inversely proportional to viscosity andtube I1, or

an associated scale, can be ma'rked oil in bands representing S. A. E. numbers as'sho'wn, or-Saybolt seconds viscosity, as desired.

' when rod 6 is depressed, 'itstrikes the right edge of bucket 39 'and forces it over, against spring tension, so that'the oil-'incompartment 3Ila and the diluent'in compartment 39b are dumped into compartment 46. 'The mixture of oil and diluent then flows through coill56, in j which it 'is further mixed, and onto screen-51 to the amount of dirt trapped by the screen. In-

strument will therefore indicate the degree'of dirtiness of the oil and the scale can be calibrated in any ,desired way suchfas in bands reading Danger, DoubtfuL'and Safe.

A slot mayIbe made in the screen near its lower edge to allow debris to be washed away by fluid from tube 65. 'It will be observed that: this fluid tends to kick thedirtupward'and another stream above the screen could be usedto help wash away the dirt.

My mixing the oil with diluentbeforepassing through the screen, the effects of temperature differences are minimized as, otherwise, coldoil would tend to form thick films over'the screen. I have found that equal parts'of oil and a diluent such as kerosene is a good proportion.

Itshould be noted that this is not merely a j color test but uses actual dirt. content as the determining factor. In fact, oil that is so dark that it appears black can be tested andthe indication will be Safe if the color is due merelyto colloidal carbon or the like. "If, however, the container is thoroughly shaken so that sludge, dirt, and

' such debris are mixed into theoil before testing, then the indication will be Danger if the oil is int-hat condition.

When the test iscompleted, button I9 is pressed down so that valves35 and I9 open the drain to cup: 3| and 'tube 'I'l, respectively, and piston22 forces cleaning fiuid'frorn tank 24through tubes 21,29, 32, and 65. Rod 5 can slide through sleeve 31 when this is st'opped by arm 36 striking the edge of trough 2 I. This causes fluid to cleantube I 1, cup 3 I, and screen 51 and associated parts, and at the same time fills compartment 391) with the diluent for the next test. Other parts such as compartment l'fi can be cleaned too.

' The depressed clearing rod 5 also carries arm 86 downward so that it strikes pin'85 on pulley 8D and forc'esthis pin down tothe position shown. 7 This causes rotation of the pulleyin a'clockwise direction tolift weight 8! to starting position.

--Ratchet 8 3 allows the clockwise rotation of the pulley. Likewise, when rod 5 is depressed, cam

94 strikes the arm of toggleswitch 93 and so cuts off the current to lamp 66. When rod 5 is released, spring I4 returns it to the position shown. Spring lll similarly returns'rod 9 to starting position, when rod- 6 is released.

thermometer pointer. This would simplify'the setting. for temperature of the fluid under .test.

In Figure 3, is shown a device for. compensating for different rates of change of viscosity'with temperature. If the temperature scale of-the testerof Figure 1 is calibratedfor an asphaltic base oil, it will not compensate correctly for a paranin base or Mid-Continent base. Similarly,

' if it is calibrated for a paraflin base oil, it will not compensate correctly for an asphaltic or Mid- COntinent oil. In practice, a scale whichis a compromise of the three scales works out very wen withm temperat'ure limits of sa 100--F. to

" 'In case greater accuracy is desired, however,

the compensator shown in Figure 3 may be used.

Equivalent parts are given the same numerals as desired. The lower end of this tube-'is packed or cemented in the" flanged upper end of cylinder 99, supported by plate 3 through which it passes. Drainopening I in cylinder 99 allows oil or other fluidin tube I! to discharge when piston IGI, vertically movable in cylinder 99,"is below the opening. "Piston I9! is-fastened toarm I92 integral with rod I93 which is vertically slidable in guide I94 attached to a convenient part of the device. This rod passes through opening I95 in plate 3 and has notches I99 and 101, one above the other as shown. Catch I98 is pivoted to a lug on plate 3 and has a spiral spring normally urging the catch to engage notch I09. Arm I09 is integral with the catch and is positioned to be struck by weight 8| when near the bottom of its path. Similarly, spring catch I Ill, pivoted to a lug on plate '3, has integral arm I I I, and is normally urged to engage notch I97.

Starting rod 6, shown in fragmentary fashion, will strike arm III to move catch III? out ofnotch I01, when the rod is depressed and'clear- 'ing'rod', also shown in fragmentarymanner,

will strike arm I02 to force piston Ifll and'rod I63 downward, when that arm is depressed.

The upper end of rod I93 is chamfered and enters cylinder I I2 which is supported on flange H3 of rod I93, acting as a valve. Cylinder H2 has inlet II 4 and catch-pan II5 to gather fluid from metering tube 33a and to guide it through opening II4 into cylinder H2. Opening H6 in plate 2 is sufficiently large to allow pan I I5 free vertical movement.

Piston II! is vertically movable in cylinder H 2 and is attached to arm I I8 which extends over cam I I9 on shaft 88 which has rotary bearing in plate 74 as before. Cam 59, which lifts arm 4| by'striking cam-4 Ia, is integral withgear speed of rotation of shaft 89 and the circumferential length of cam 80b. Pulley 89 extends out from disc'illla, and arm 89 adapted to strike resilient arm 71 to knock it from shelf 78, is attached to cam H9, on one face, so that the arm will not interfere with the operation of l the cam.

7 As before, there is a friction connection between shaft 88 and the knob (not shown) which is attached to the forward face of cam H9. The starting mechanism or latch may be similar to that shown in Figures 1 and 2.

Shaft 88 is driven by gear 83 in counterclockwise rotation, either directly or through a ratchet. Cam H9 and arm 89 are rotated by the shaft or shaft and knob, by means of friction as described. The escapement 90 and cooperating toothed wheel regulate the rate of rotation of gear 83 by falling weight 8I, insuring uniform rotation.

In operation, a sample of oil, say, is placed in cup 3| and the temperature is read on a suitable instrument, as before. Then arm 89 is set relative to temperature scale 89a, being positioned closer to cam 19 the higher the temperature. This scale is calibrated to compensate exactly for changes of viscosity of a chosen oil of a particular viscosity index, say a Mid-Continent base oil. Then, if the valve is open, oil will flow through tube 33 and will rise in viscosity tube IT to heights inversely proportional to the viscosity of the oil, before the flow is stopped by the timed valve. After the starter is released, cam Ma is struck by cam 19 and strip IT is lifted onto shelf 18 so that valve 40 is lifted until arm 89 is rotated around and strikes strip I7 a sidewise outward blow and knocks it off shelf "I8 so that valve 40 is dropped to stop flow of the oil through metering tube 33.

Since scale 89a was calibrated with oil of the same base or viscosity index, the heights to which oil of the same base will build up in tube I! will be very accurate indications of viscosity, since the temperature compensation is accurate. The scale on, or adjacent to tube Il may be in S. A. E. numbers or in Saybolt seconds.

If, however, an oil of a different base, such as asphaltic or parafrlnic is tested, scale 89a will not accurately compensate for variations of temperature of the oil. These oils change viscosity at different rates, with respect to temperature change, as compared to some Mid-Continent oil, for instance.

In order to compensate for the varied viscosity indications due to different bases of oils, when temperatures vary, the mechanism shown has been added. As cam 19 is rotated, cam 8012 on disc 80a is likewise rotated counterclockwise to strike cam 4Ib to lift arm Mo and valve 40a for a predetermined, relatively short time interval. This interval may be the same for all tests. This results in flow of the oil under test through metering tube 33a for the aforesaid interval and this oil strikes scoop I I5 and flows through passage I M and into cylinder H2. The initial position of rod I03 was so that catch H engaged notch I0? and piston ISI was accordingly held below opening I00 so that drainage from tube I! could take place through opening I00. At the same position, scoop H or a lug on cylinder H2 could strike a bracket depending from plate 2 so that valve H3 would be lowered to allow drainage from cylinder I I2.

When starter rod 6 is depressed, arm III is struck so that catch H0 releases rod I03 which is pulfed up by tension spring I20, attached to the rod and to plate 3, and piston IOI closes opening I00 and valve I 43 is quickly lifted to seal the bottom of cylinder H2 against leakage. Spring catch Hi8 falls into notch I05 to stop the upward movement of rod i53 in the position shown.

Spring I2 I, attached to arm H8 and to plate 2,

oil

tends to pull piston IIl down into cylinder II2 but is normally prevented from moving the piston by latch I22 pivoted at I23 to lug I24 fastened to plate 2. A suitable spring fastened to latch I22 and to lug I24 normally tends to hold the latch in vertical position shown, supporting arm H8.

Cam H9 is so shaped that it allows arm H8 only slight downward movement, when released, for high temperatures, and increasing down- Ward movement of the arm before striking the cam as a stop, as the oil temperature under test is lower. The cam shape is chosen so that the calibrating oil which flows into cylinder I I2 as a result of passing through tube 33a while the valve 40a is lifted, will rise in cylinder H2 to heights increasing with the temperature of the oil and just suflicient to meet the bottom of piston IIl when arm H8 is supported on cam H9. It will be observed that arm or pointer 89 is attached to cam H9 so that when the arm is set relative to temperature scale 89a, for the temperature of the oil under test, cam H0 is correspondingly rotated so that the topmost position of the cam at that temperature will be such that the bottom of piston Ill will just touch the surface of the calibrating oil which has flowed into cylinder H2. Therefore, when weight 8I nearly reaches its lowest position and strikes arm I09 to cause catch I08 to rotate out of notch I00 to release rod I03, there will be no movement of rod I03 for the calibrating oil, since the cylinder chamber is filled to the level of the bottom of piston II'I.

Spring I2I is chosen of greater strength than spring I so that it can, if not stopped, force rod I03 down against the upward pull of spring I20. Latch I22 is struck by cam I25 on gear 83 when the gear is near its maximum rotary counterclockwise displacement. Therefore latch I22 is knocked from under arm I I8 at this point and spring I2I pulls piston II'I down until arm H8 strikes cam H9. Opening H4 in cylinder H2 is covered with slight downward movement of the piston. Arm H8 may be lifted back on latch or prop I22 by means of arm I26 which is lifted by a suitable lever operated by clearing rod 5. The dimensions of tube 33a, cam 80b, and cylinder I I2, are so chosen that the maximum flow of any fluid likely to be tested will not fill the cylinder quite up to opening H4. It will be seen then that as long as any oil tested has the same viscosity index as the calibrating oil, the rod I03 and consequently piston IOI will remain in position so that the level of the test oil in tube I1 will indicate true viscosity.

Now suppose that the oil tested varies in viscosity at a greater rate than the calibrating oil, i. e., it becomes less viscous for a given temperature. Then, during the time that valve a is lifted, the test oil will rise higher in cylinder H2 than the calibrating oil would and, when arm I I8 is released so that it is pulled down against cam H9, properly set for the temperature by pointer 89 and scale 89a, the piston II! will strike the oil in cylinder II 2 and will force rod I03 and piston IOI down for a distance equal to the difference between the height of rise of the calibrating oil and that of the test oil, in cylinder H2, for the particular temperature involved. This lowering of piston IOI will correspondingly lower the height of the oil in tube I1 so that a compensating eifect is achieved. The diameter of piston III may be the same as the diameter of piston IN, or otherwise.

In similar manner, but in the reverse sense, if the oil under test is more viscous with changing temperature than the calibrating oil, the test oil will not rise sufiiciently high in cylinder H2 to meet the bottom of piston I I1 and so spring I20, when catch I08 releases rod I03, will pull that rod and piston Hll upward until the oil in cylinder H2 strikes the bottom of piston Ill. The level of the oil in tube ll Will therefore be lifted to indicate corrected viscosity.

It is obvious that a fixed travel of piston H1 could be used and valve 40a could be attached to bar 4|, as shown in Figure 4, so that the time interval of flow through tube 33a would be substantially the same as that for the flow through tube 33. In this case, the time of opening of valve 400. would be adjustable for temperature.

While I have shown several modifications of the invention, I realize that many variations can be easily contrived by others without departing from the broad concepts I have disclosed.

What I claim is:

1. In a viscosity testing device, in combination, a container for fluid, a metering orifice in said container for discharge of fluid therefrom, a valve for said orifice, means including timing means for opening said valve for predetermined intervals of time, another orifice in said container, another valve for said other orifice, means including said timing means for opening said other valve for a predetermined interval of time, a transparent tube to receive fluid discharged from said metering orifice, a scale for indicating viscosity as determined by height of fluid in said tube, valve means for said tube including a piston to control fiow of fluid therefrom, movable means to operate said valve piston, a vessel carried by said movable means and adapted to receive fluid discharged from said other orifice. a piston movable in said vessel to trap said fluid therein to cause movement of said movable means said tube valve means comprising a cylinder having an aperture and said valve piston slidable in the cylinder to cover said aperture and also to vary the viscosity indications in accordance with the movements of the vessel, and stop means settable in accordance with the temperature of said fluid for limiting movement of said piston.

2. Same as in claim 1, and including means for moving said vessel piston.

3. Same as in claim 1, the vessel carried by said movable means having an inlet and an exit port for said fluid.

4. In a viscosity testing device, a container for fluid, a metering orifice in said container for discharge of said fluid therefrom, a valve for said orifice, means including timing means for opening said valve for predetermined intervals of time, another orifice in said container, another valve for said other orifice, a movably mounted vessel to receive discharge of fluid from said other orifice, a piston movable in said vessel, means responsive to quantity of fluid discharged from said metering orifice for indicating viscosity, means including a movable member connecting said viscosity indicating means with said vessel so that movements of said vessel effect proportional movements in said viscosity indicating means, and means including a movable member connecting said timing means with said other valve to open said other valve for a predetermined interval of time before opening of said metering orifice valve.

5. In a viscosity testing device, a container for fluid, a metering orifice in said container for discharge of fluid therefrom, a valve for said orifice, timing means including a rotatable member for opening said valve for predetermined intervals of time, a temperature scale on said rotatable member, another orifice in said container, another valve for said other orifice, means responsive to quantity of fluid discharged from said metering orifice for indicating viscosity, means including a movable member connecting said timing means with said other valve to open said other valve for a predetermined interval of time before opening of said metering orifice valve, means movable in proportion to the quantity of fluid discharged from said other orifice, means including a movable member connecting said movable means with said viscosity indicating means to effect movement of the latter in accordance with movements of said movable means, and means for limiting the degree of movement of said movable means in accordance with the temperature of said fluid.

6. In a viscosity testing device, in combination, means including an orifice for testing viscosity of a fluid as determined by quantitative flow of said fluid through said orifice during a predetermined period of time, means including a scale for indicating viscosity, other means including an orifice and responsive to the viscosity index of said fluid as determined by quantitative flow of said fluid through said second named orifice during a predetermined period of time, and means including a movable member connecting said means responsive to viscosity index with said viscosity indicating means to effect displacement of said viscosity indicating means in accordance with the viscosity index of said fluid.

7. Same as in claim 6, and including means incorporating a temperature scale, a member settable relative thereto, and an element varied in position by movement of said member to limit movement of said other means for adjusting the degree of responsiveness of said other meansaccording to temperature of said fluid.

8. In a viscosity testing device, in combination, means for testing viscosity of a fluid as determined by relative flow of said fluid with respect to said means, means for starting said flow and stopping said flow after a predetermined interval of time, means including a scale for indicating viscosity, other means for determining the viscosity index of said fluid as a result of relative flow of said fluid with respect to said other means, means for starting said flow and stopping said flow with respect to said other means after a predetermined interval of time, means including temperature scale means and timing means settable relative thereto for predetermining said intervals of time, and means including a movable member connecting said viscosity indicating means with said other means to effect displacement of said viscosity indications in accordance with the viscosity index of said fluid. ALBERT G. THOMAS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,022,578 Thomas Nov. 26, 1935 2,068,476 Thomas Jan. 19, 1937 2,091,222 Thomas Aug. 24, 1937

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