US1673520A - Method of maintaining a constant volume in the air chamber of liquidquantity-indicating devices - Google Patents

Description

June 12, I928,

J. MACCALLUM,

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' METHOD OF MAINTAINING A CONSTANT VOLUME IN THE AIR CHAMBER Patented June 12, 1928.

UNITED 1 STATES PATENT OFFICE.

JAMES MACCALLUM, JR, OF UNIVERSITY CITY, MISSOURI.

METHOD OF MAINTAINING A CONSTANT VOLUME IN THE AIR CHAMBER OF LIQUID- QUANTITY-INDICATING DEVICES.

Original application filed June 5, 1920, serial No. 386,674. Divided and this application iiled November 8, 1926. Serial No. 146,615.

My invention relates to improvements in the method of maintaining a constant volume in the air chamber of a liquid quantity indicating device and has for its primary object the method of automatically maintainin the volume in the pressure chamber of an indicating device constant by supplying additional air to said chamber by the movement of the liquid in a container.

A further object is to supply air or other gaseous pressure carrying medium to the pressure chamber of a quantity indicating device during the filling of the container.

A still further object is to aerate the liquid while being poured into the con.-

tainer and to discharge a portion of this aerated liquid beneath the pressure chamber of a quantity indicating device where the air will release itself from the liquid and ass beneath and into the pressure cham er and thereby restore any loss of volume in the chamber.

One serious objection to quantity indicators of the pressure type is that a diminution of the pressure carrying medium used to operate the indicator caused either by the contraction or com ression of the gaseous medium in the con uit and pressure chamber or by 'the absorption of said gaseous medium by the liquid or by temperature changes or other hydrostatic phenomena, which cause a change in volume, permits liquid to; enter the pressure chamber result ing in an incorrect reading of the indicator or gauge. Prior inventors have sought to overcome this objection by providlng a pump or compressor by means of which air under pressure can be admitted to the pressure chamber or conduit at intervals to compensate for the absorption or loss of volume in the chamber and thus re-establish correct pressure. Others have attempted to overcome this objection by providing a tube to which the operator places his mouth and by blowing restores this loss in volume, but by these various methods considerable attention was required-on'the part of the user to maintain them in operative condition and, if not attended to at proper intervals, the indication would be incorrect but by my method no such attention is required.

This application is a division of my application filed June 5th, 1920, Serial No. 386,674 for quantity-indicators for liquids.

In the drawings:

Fig. 1 is a vertical sectional view of a quantity indicator for liquids by which my method can be carried out; and

Fig. 2 is an enlarged vertical sectional view of the pressure chamber and certain of the parts that are associated with the same.

In the construction of my device 3 represents a liquid container, or tank. This tank is provided with a bottom 4, in which an opening 5 is formed. Around this opening issecured a ring 6, which has a portion 7 proj ecting upwardly into the tank, thus forming a. sediment trap. This upward projection is provided with a right-angular downward projection 8, the outer face or vertical portion of which is provided with screw threads 9, over which a clamping ring 10 is adapted to be secured. Projecting within the container, or tank 3 is a cup 11, that surrounds the lower portion of a pressure chamber 14, said cup being provided with a plurality of outwardly bent portions or flutes 12. These flutes form passages 13 between the cup 11 and the air pressure chamber 14. The air pressure chamber 14 and the cup 11 are secured together at the portions of the cup located between the flues. The air pressure chamber 14 is provided with a. concave bottom 15, the center of which is rovided with a depressed portion 16. The epressed portion has the openings 17 formed therein, as well as acentral openin 18 through which the portion 19 of the draining plug 20 passes. The cup 11 is rovided with a horizontally projecting portion 21 that forms a flange 22. After the flange 22 has been formed, the material out of which the cup is constructed again extends horizontally toward the center, thus forming a horizontal portion 23, and between the horizontal portions 21 and 23 is securely clamped the flange 24 of the defleeting shield 25. This deflecting shield is made convex and has a central opening 26* through which the portion 19 of the drain plug passes. The cup 11, as well as the defleeting shield 25, are provided with openings 26; these openings registering and allowing communication between the tank and the underside of the shield 25. Through one of these openings is inserted the end 26" of the filling spout 27. This spout is provided near its upper end with the perforatedienlargement 28, the perforations allowing the escape of liquid into the tank in the event the liquid is poured in faster than the .end 26 will permit to escape. These perforations permit, as is obvious, the ingress of air into the tube 27 and a certain volume of air will be contained in said tube above the liquid within the tube. The air above the liquid within the tube will be displaced and carried down through the tube and discharged with the liquid by the weight and movement or pres sure of the liquid which is splashed through the openings when the liquid in the container is agitated. Secured to the upper end of the enlargement 28 is the cup 29, which has air vents 30 formed therein. Within the container is located the air pipe31, which has its end 32 secured to the top of the compressed air chamber 14, its end 33 being secured within the coupling 34. This coupling is secured through the side of the container 3 by means of the lock nut 36 and to this coupling is secured the pipe 35, which has its opposite end secured to the gauge 37. The filler pipe 27 is provided with a flange 38 so that it can be attached to the container by means of screws 39. Within the filler pipe is secured a rod 40, which projects entirely across the opening and is for the purpose of splitting the flow of liquid while being poured into the container and thus allowing it to grasp and hold a certain amount of air in the form of bubbles, which are delivered by the liquid underneath the shield 25.

The operation of my device is, as follows:

The container being empty, there is only atmospheric pressure within the pressure chamber 14; when the filling of the container is commenced the liquid will pass down through the filling tube 27, be split by the rod 40 and become aerated i. e., carry air in the shape of bubbles with it, and out through the opening 26, which air will be released from the liquid and strike the under portion of the shield 25. The liquid will continue to pass and rise until a liquid seal has been formed, which will be when the liquid contacts withthe bottom edge of the air pressure chamber. After this seal has been formed the'bubbles will rise through the liquid and lodge against -the bottom 15, and after a suflicient amount of air has accumulated underneath the bottom to uncover the openings 17, the air will be permitted to enter these openings and rise upward in the air pressure chamber '14 and also fill the space beneath the bottom 15 to the lower edge of the pressure chamber. As the liquid continues to flow through the pipe 27, it will flow through the passageways 13 formed by the flutes 12 and openings 26 and thereby seal the air against escape, and also exerts an upward pressure on the air in the chamber. The air pressure set up within the chamber is sutficient to prevent the entrance of liquid. As the height of liquid in the tank increases, the pressure in the chamber increases proportionately. The be transferred to the gauge 37 y means of the pipes 31 and 35, and thus indicate the quantity of liquid within the container.

It is a well known fact that liquids, especially when confined and caused to exert pressure on air, or other gaseous medium, will absorb a certain amount thereof, and in or der to make my device accurately operative an additional supply of air or gaseous medium to take the place of that absorbed must be furnished or the device would become inaccurate. This additional medium is supplied by the replenishing of the liquid in the tank through the spout 27 and a so by the splashing of the liquid in the tank into the openings or perforations of the spout when the liquid is agitated. When it is desired to drain the entire tank, or in the event that the openings become clogged the sediment plu 20 may be removed and the entire tank was red out without disturbing any of the pipe connections or the filter tube.

One purpose of forming the openings 1n the enlarged portion 22 is that when liquid is forced into the tank from a measuring pump the opening 26 at the bottom of the filler tube will not be sufficient to allow all of the liquid to pass therethrough but the tube 27 will become filled and have a sort of checking effect on the liquid contained therein; when this occurs the openings will allow the excess liquid to pass therethrough and into the container.

It is obvious that the perforations formed in the enlargement 28 will permit the ingress of air into the tube 27 and this free air, as distinguished from the air in the liquid, will be discharged downwardly through the tube and escape with the liquid contained in the tube, beneath the air pressure chamber. My invention contemplates two methods of replacing the absorbed air in the air pressure chamber. One is by means of the liquid poured through the tube and the other by means of the air admitted either as trapped air or as air contained in the liquid which passes through the perforations by the splashing of the liquid in the tank when the said liquid is agitated. It is obvious that in the movement of the vehicle on which the a )paratus is used a certain quantity of liqui will pass through the perforations and will enter the tube and be discharged beneath the pressure chamber. This splashed liquid contains air which will escape in the form of air bubbles into the ressure chamber, and, as previously pointe out, a certain quantity of air will also pass into the tube 27, and form above the liquid level in the tube, and when the volume of splashed prcssu re will liquid through the openings is greater than the volume of the liquid below the air, this air will be trapped and also be discharged beneath the air pressure chamber.

In order to carry out my method by a device of this character it is obvious that in order for the gauge to operate accurately that a constant volume of gaseous pressure medium must be maintained in the chamber 14, and broadly speaking the object of my invention is to maintain this volume constant automatically regardless of any cause which contributes to fluctuations or variations of this volume.

It is also obvious that the method described herein is not limited in its applications to use in connection with tanks or containers for gasoline or other volatile hydrocarbons nor only where air is the gaseous pressure medium used in the pressure chamer but it is apparent that my method may be used in connection with other liquids and other gaseous media in the pressure cham' ber can be employed than those specified without departing from the spirit of my in.-

vention.

Having fully described my invention, what I claim is 1. The method of supplying air to the pressure chamber and line of a quantity indicator for liquids within a container which consists in confining against diffusion the air to be supplied, imparting movement to the liquid to be measured by moving the container, and utilizing the movement and weight of said liquid to deliver said confined air to the pressure chamber.

2. The herein described method of supplying air to maintain a normal liquid level in the air pressure chamber of a quantity indicating device for liquids which consists in agitating a liquid containing trapped air delivering said liquid and air beneath sai chamber, and then permitting said air to rise and pass into said air pressure chamber.

3. The method of supplying air to the pressure chamber in a quantity indicating device for liquids, which method consists in agitating the liquid so as to separate an independent volume of liquid from the main body thereof, and utilizing the volume of liquid while being se' arated to trap air and the weight of sai separated liquid to force'said trapped air beneath and into the pressure chamber.

4. The method of introducing air into the pressure chamber of a quantity indicator for liquids, which is located below the surface of the liquid and in communication therethe same beneath the surface of the liquid and into the pressure chamber.

5. The method of automatically delivering air to the pressure chamber of a quantity indicating device for liquids within a container, which pressure chamber is submerged in and communicates at its bottom with said liquid, which method consists in impartin movement to the liquid to be measured and thereby elevating portion thereof in such manner as to entrap air therein, confining said entrapped air and the portionof the liquid which has entrapped it against lateral diflusion, the weight of said liquid above the entrapped air causing said air to be forced downwardly so as to deliver the same beneath said pressure chamber to maintain the volume therein.

In testimony whereof I have aflixed my signature.

JAMES MACCALLUM, J R.

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