US2265736A - Tank gauge - Google Patents

Description

Dec. 9, 1941. D. E, LARsoN- 2,265,736

TANK GAUGE Filed Dec. 30, 1940 2 Sheets-Sheefl 1 ft w i Zig' .2 y W# (l KQ /3 \\O 9, 1941. l D. E. LARsoN I TANK GAUGE Filed Dec. 30, 1940 75 ma@ ZZ/ Jaffa/a www l Patented Dec. 9, 1941 TANK GAUGE Donald E. Larson, Chicago, Ill., assgnor to Chiy cago Bridge & Iron Company, a corporation of Illinois Application December 30, 1940, Serial No. 372,381

(Cl. Sii-126.6)

9 Claims.

This invention relates to improvements in tank gauge and more especially such a device for measuring the height of liquid in a container. The invention is particularly applicable for use in connection with oil storage tanks and more especially closed tanks. similar volatile hydrocarbon oils are frequently kept in closed containers under pressure. My'device can be used with such a container and operated at all times without releasing the pressure or venting the gas from the container.

`My improved device is also useful in connection with a container having a iiexible roof. The device is mounted on the roof and vertical movement of the latter does not affect the gauging operation.

Other features and advantages of my invention will appear` more fully as I proceed with my specification.

In that form of device embodying the features of my invention illustrated in the accompanying drawings, Fig. 1 is a view in front elevation; Fig. 2 is a view in side elevation; Fig. 3`is a vertical sectional view of the reeling mechanism; and Fig. 4' is a view taken as indicated by the line 4 of Fig. 3.

As shown in the drawings, I mayindicate a roof or top of a tank such as an oil storage tank. II indicates in general a casing suitably mounted on the roof in any convenient manner.

The upper part of the casing as indicated by I2 contains reeling means for an elongated ilexible element such as a steel tape carrying a Weight or bob on the lower end. By means of the reeling mechanism the lower end of the tape may be raised or lowered to raise or lower the weight. As

`so far described, the gauging mechanism is conventional. It has been the practice t0 lower the weight until it engages the bottom-of the tank and then pull up the tape and note the height of the wet portion. The tape may be suitably coated so that the line between the -Wet and dry por- -tions can be easily noted. 'I'his is all old in the art.

Heretofore, difliculty has been encountered in noting just when the weight engages the bottom of the tank. Unless the weight is very heavy, the differences in tension caused by the Weight strik-- ing the bottom was not readily ascertainable at the top. The principal feature of my invention is the provision of automatic locking means for the reeling mechanism so that when the Weight strikes the bottom the reeling means will be automatlcally locked. This prevents the lowering of additional tape into the liquid that obviously For example, gasoline and would give a false `indication of the height of the liquid in the tank.

In general, my invention is accomplished by providing locking means for the reeling mechanism which is normally in locking position and providing in conjunction therewith means operated through the exible element by the weight when suspended thereby forholding the locking means in release position. When the weight engages the bottom of the tank it 4no longer holds the locking means in release position and said' locking means thereby movesv automatically to locking position to hold thereeling means sta- I3 indicates a reel or drum mounted on the shaft I4 operated by the 4handle I5. Where the f shaft projects from the casing I2 suitable packing is provided as indicated by I6. I1 indicates a' steel tape wound on ythe drum I3 carrying on its lower vend the bob or weight I8 adapted to engage the bottom I9 of the tank when in its lowermost position.

The lower part of the casing I I is provided with a chamber 20 containing closure means (not shown) adapted to close the casing II against escape of gas from the tank' and yet permit the tape I1 to remain thereon. Such closure-means is well known in the art and forms no part of the present invention and consequently need not be shown here in detail. It is ordinarily provided to permit opening of the window-2| in the casing II, if desired, without permitting escape of gas therefrom. A

'I'he dru I3 at one side carries the ratchet wheel I3a, he teeth of which are adapted to be engaged by the claw 22 on the end of the arm 23 pivoted on the stationary pin 24. The arm 2l.

.is provided with a rearwardly extending portion 23a adapted to be engaged by the arm 25 pivoted at 2Q and carrying the Wheel 21 on its free end over which the tape I1 passes. The arm 25 is provided with an extension 25a in the nature of a bellcrank connected to lthe tension spring- 28 which tends to move the arm 25 into the dotted position shown in Fig. 3; that is, with the wheel 2'l raised. When in this position the claw 22 on the small lever 23 falls into locking position or engagement with the teeth on the ratchet wheel normally pressed member 30, carried by the extension casing 3l on 30 is stationary in the casing. 3 I is carried on the crank 32 pivotally mounted to the member 33 on the shaft I4. Normally the members 28 and 30 are in frictional engagement to prevent rotation of the shaft. To release these the crank 32 is swung on its pivot 34 to press the member 29 inwardly against the' tension of the spring 35 to release the clutch to permit ro-y tation of the shaft. Upon release of -the handle 1 I5 the clutch is automatically engaged.

In operation, before the gauging is commenced, the parts are in the position shown by the solid lines in Fig. 3. In this position the weight' is suspended by the tapeV I1 and is heavy enough Qto extend the spring 28 so that the arm 25 is `engaging the end 23a of the locking lever 23 to @hold the same in released position. The tape is `then unreeled slowly until the bob I8 engages i the bottom I9 of the tank. As the weight of the bob isthen removed from the tape I1 further unreeling causes the spring 28 to raise the arm` `25. This permits the claw 22 to drop into engagement with one of the teeth on the wheel I3a `and lock the reeling mechanism against further unwinding. The tape is then wound up and the height of liquid thereon noted throughv the.

window 2|.

It is to be noted further that the device automatically locks the reel and simultaneously insures application of tension to the tape I1 through the action of the spring 28. This tension is not of an exact predetermined value, but it is substantially constant through general limitsand is suicient for ordinary gauge indications.

`If the top of the tank moves upwardly a small amount after the reel has been locked, this small movement is accommodated by action of the spring 28 to maintain a substantially constant -tape tension. If greater upward movement at the `top of the tank occurs, then the ratchet 22 unllocks for one or more teeth of the ratchet wheel, lthus automatically maintaining tension and in- I `surng that the weight remains in contact with the bottom. Should the top of the tank move `downwardly from its initial position, then this movement is accommodated by the relative up- `ward movement of the reel 21 under the action `of spring 28.

, The action of the spring 28' in conjunction `with theratchet 22 is to automatically apply the `casing II around the shaft I4. The member The handle I A 2 v 2,265,736 l when the handle I5 is released. 29 indicates a 1 clutch member slidably. but non-rotatably mounted on the shaft I4 an a A r into engagement with the cooperating clutch Changea'therefre, in the construction and arrangement may be made without departing fromv the spirit and scope of the invention as disclosed in the appended claims, in which it is my intention to claim all novelty inherent in my invention as broadly as permissible, in' view of the prior art.

What I claim as new and desire to secure by Letters Patent is:

1. A tank gauge,including: an elongated ilex-A ible element adapted to extend down into the tank; reeling means adjacent the top of the tank to raise'or lower the lower end of the flexible element; a weight carried by the lowerv end of the flexible element; locking means for the reeling means; means operated through the flexible element by the weight when suspended thereby for holding the locking means in release tension on the tape after the weight has engaged l the bottom of the tank, and to maintain tension y irrespective of movement of the top of the tank.

`In other words, the action of the spring 28 in commotion with the ratchet' 22 automatically `applies tension on the tape after the weight has v engaged the-bottom of the tank and maintains tension irrespective of the movement of the top of the tank. It is generally desirable to apply a more or less uniform tension to the ltape during the taking of readings in order to prevent inaccuracies. In other words, the spring 28 acts as a biasing means in conjunction with the re-r ;leasable locking means for automatically apply- Aingsubstantially uniform tension to the tape `when the weight rests on the bottom of thetank.

position; and means for imposing a tension on the flexible element v(insuiiicient to" lift the weight) when the locking means is in locked position.

2. A tank gauge, including: an elongated ex. ible element adapted to extend down into the tank; reeling means adjacent the top of the tank to raise or lower the lower end of the flexible element; a weight carried by the lower end of the flexible element; locking means for the -reeling means; means urging the locking means 4. Apparatus as claimed in claim 2 in whichv the means operated by the weight includes a .movable member carrying a wheel over which the exible element lies.

5. Apparatus as claimed in claim 1 with a handle for operating the reeling means and clutch mechanism for holding the reeling means against rotation, said clutch mechanism adapted to be released by movement of the handle to operative position.

6. Apparatus as claimed in claim 2 with a handle for operating the reeling means and clutch mechanism for holding the reeling means against rotation, said clutch mechanism adapted to be released by movement of the handle to operative position.

7. In combination with a tank having a. vertically movable top, a tank gauge, including: an elongated flexible element adapted to extend down in to the tank; reeling means adjacent the top of the tank to raise or lower the lower end of the flexible eiment; a weight carried by the lower end of the flexible element; and means for maintaining substantially uniform tension on the elongated exible element after the weight touches the bottom of the tank, regardless of vertical movement of the topvof the tank within limits.

8. In combination with a tank having'a vertically movable top, a tank gauge, including: an elongated exible element adapted to extend v down into the tank; reeling means adjacent the While I have shown and described certain embodiments of my invention, it is to be understood that it is capable of many modifications.

top of the tank to raise or lower the lower end of the exible element; a weight carried by the lower end ofthe flexible element; locking means for the reeling means normally in locking position; and means for automatically maintaining substantially uniform tension on the elongated flexible element after the weighty touches the tank; a weight carried by the lower en d of the flexible element;4 Vreeling means normally free for rotation when the weightis suspended by said elongated exible element; llocking means for the reeling means; means releasable by decreased tension on said elongated flexible element to release said locking means and lock said reeling means, said releasable means operating to impose a tension on the flexible element (insucient to lift the Weight). when the locking 10 .means is in locking position.

DONALD E. mason.

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