US1801763A - Liquid tank for concrete-mixing apparatus - Google Patents

Description

April ,1 J. E. BUSHNELL LIQUID TANK FOR CONCRETE MIXING APPARATUS Filed May 2 192 awuemtoz Z Patented Apr. 21, 1931 UNITED STATES PATENT, OFFICE JAMES 'E. E sHNEL' or non'rn rEnmEIE n, NEW JERSEY, AssIcNoE 'ro. RANSOME concaErE MACHINERY coMrA vY, or rLArnErE n, NEW JERSEY, A CORPORATION OI NEW JERSEY LIQUID TANK ron ooncEErE-MIxrne APPARATUS --A pp1ication filed May 2, 1 928. seriai'no. 274,415.

The present improvements relate, in gen-- eral, to concrete mixing apparatus and more particularly to a water measuring 1 means used in conjunction therewith.

In devices adapted for preparing freshly mixed concrete forplacement, it has become of increasing importance that a definite proportion of water and dry aggregates, etc., be maintained for each given batch. 'As the 19 proportions for each batch to be mixed, may vary, it is essential that'a measuring means for the .water be provided which, not only will accurately measurethe quantity to be discharged into themixer but also will be rugged and durable, simple to operate, have a minimum of parts and function with equal accuracy on all grades in which the apparatus may be positioned.

The present improvements accordingly, 29 have as their primary object among others,

the provision of a measuring tank, embodying the foregoing desirable features, and having means positioned within the tank for predetermining the discharge therefrom. Another important object is to provide means for reducing the effective water surface within the tank, so that when operating on grades or under other unfavorable circumstances, the quantity of \water affected the water seeking its own level, is reducedto aminimum. m T

Various other objects and advantages of the present improvements will be apparent to those skilled in the art upon reference to the accompanying drawing inwhich 1. The figure illustrates a water tank :in section, embodying the present improvements. The measuring tank lris mounted on or adjacenttheccon crete mixing machine and is conveniently positioned with respect to thecharging openingof the rotary drum of said machine whereby the measured contents of the tank maybe discharged through pipe 7 into said drum. The general organization of such a mixer is well lmownand comprises, among other elements, means for introducing cement, aggregates, water, etc.

preparatoryto placement,

by the consequent tilting of the tank "due to into a rotary mixing drum ,to'be commixed Means for admitting water to the tank 1 comprise supply. conduit 2, T 3, pipe 4 and elbow 5, all being controlled byvalve 6 in conduit .2. Although an independent discharge line forthe tank may be provided, for convenience of assembly and" simplicity, the discharge from the tankis effected through elbow 5, pipe 4, T 3 and discharge pipe 7. f Thelatter pipe'controlled by valve 8, leads to and discharges into the mixing 'drum, along with the cement, dry aggregates, etc., from a skip (not shown). Obviously when-charging tank 1, valve 6 is open and valve 8 is closed, While upon discharge of the tank, valve 6 is closed and valve 8 open; Preferably, but not necessarily, these valves are interconnected for simultaneous actuation, and may be either operated manually, or by a connection running from the pivoted skip wherebythey are responsive to elevating and lowering of said skip, all so arranged that the tank and skip may be charged and discharged simultaneously.

' Mechanism of the character described and claimed in the U. S. Patent No. 1,691,031, granted Nov. 13, 1928to Helge A. Burle, maybe provided for insuring proper sequential operation of the valves 6 and 8.

The tank 1 is provided with a clean-out port Qor'drain 9, water gauge 10 and vent valve 11. If desired,the vent valve llmaybe replaced by an overflow pipe, the water from supply conduit 2 being turned 01f when the tank is full, as indicated by discharge through such overflow pipe.

A vertically movablevessel, casing or drum 12 is disposed within the tank 1, beingof slightly less diameter than said tank, so that asmall clearance 25 existsbetween the respective vertical walls thereof. Said drum is convenientlysuspended for vertical movement on screw shaft 13,-one end of which enters said Vdrumthrough threaded nut 14. Said shaft 13 projects through the tank and has keyed thereto or otherwise connected therewith, at its outer end, a hand wheel'15 having a gear 16 rotatable therewith. By rotating said Wheel, the drum 12 is caused to travel vertically within tank 1 through the coaction of screw shaft 13 and nut 14. Rotation of the drum is prevented by reason of contact between elbow and the walls of a vertical recess 17 in drum 12.

Indicating means 18, actuated by :gear 1-6 through gear 19, are provided for indicating the quantity of water discharged from the tank. A small receptacle 20 having perforations 21 andweep-hole"22,isiiXed above and in alignment with elbow 5. "Saidreceptacle is substantially of the same size as recess 17 in drum 12 and is positioned so as nottointerfere with the vertical travel of said drum. One or more ports 23 are provided in the top of drum 12, and a valve controlled drain 24 is located in the base thereof.

As illustrated, the drum 12 occupies :a substantial portion :of the interior =o the tank and when positioned at the lower extremity of its travel, it-occupies substantially the -:en- .tire area ofthe tank 1 beneath :inlet and outlet elbow a. The diameter of :drum' 12 is slightly less than that of tank-1, so that the former has lfreedom of movement within the tank. The clearance indicated-at 25 between the tank and drum Walls is :thus reduced to :a minimum.

The tank 1 may be filledin any'position on": drum 12. Upon opening of supply valve 6, water enters the tank through elbow 5 descendingthrough recess'li. When the water level reaches the base of drum 12, 'it ascends around the drum, through clearance 25 and recess 17 until the level reaches the top of the drum. W'ater then enters :clrum 12, by way of ports 23, until filled, whence the-level rises filling receptacle 20, in time the-entire tank and ultimately closing vent valve 11. It will be noted that the water pressure obtaining on the-exterior .oi the wall-sot the drumis vequalizedby the water present within said drum, so that no undue strain is placed on the drum walls. This provision is particularly important and" desirable where large units are required thereby necessitating the use oat large tanks. In such installations the inner drum is called upon to withstand enormous water pressure and is of such a size asto require the equalizing means to prevent collapse.

Assuming that the'tank has been filled with the drum in the illustrated position, to discharge the tank, valve 6 is closed and valve 8 opened whereby all thewater in the tank above the level of the mouth of elbow 5 except that in drum 1-2 and receptacle 20," is discharged by gravity through pipe 7 to the miner. Af er the initial filling of the'tank, subsequent filling thereof may be accomplished more speedily since thedrum 12 and receptacle 20 remain full, the dripping from weephole 22 in the latter being negligible;

Should it be desirable to discharge a smaller quantity of water than that dispensed in the operation above described, the hand Wheel 15 is rotated until indicator 18 designates the desired quantity, at which time the drum 12 is simultaneously elevated to dotted line position, for example. The water space between the top (sfull line) of drum tion, comprises that amount above the drum,

and obtaining in the annular clearance space 25, and also that between the walls of meceptacle .20 and recess 17, which is above the level of elbow 5. It is thusseen that the effective discharge of the tank may be varied Without affecting its capacity. Furthermore, thedrum may be set at any desired position in the tank, thus displacing a portion'of and reducing the effective discharge area thereof.

When the drum is in dotted line position, receptacle 2O displaces the water which would otherwise obtain in recess 17, so that :a minimum waiter space is maintained below the level of the drum top.

it is not uncommon for anixing apparatus of the type carrying measuring tanks, to be set up for operationon uneven terrain or on grades, with consequent false measuring of the water due to variations caused by the water within the tank seeking its own level. Depending upon the direction of the tilting of the tank, the water discharged may be greater or less than that indicated as re quired. As requirements for a concrete mixture with respect to the prescribed proportions of the ingredients, are rigidly enforced by inspection, it is essential that any deviation 1 above or below the determined quantity of water, be reduced to a minimum and held within limits bracketing the fixed standard, any deficiency or excess within said limits being ineilec-tual to mar the eiliciency of the batch.

hen a mixer, having a tank embodying the present improvements, is positioned on a grade or under similar conditions, the water obviously will seek its own level. Let it be assumed tha-tthe drum 12 is set anywhere in the tank, e. g, at the dotted line position, and

has been filled with water as described. Upon discharge, as the water level recedes, said level will be in a plane at an angle to the normal horizontal of the tank, due to the inclination of the tank, causing a higher water i 1 level on one side of the tank than at the opposite side.

In that portion of the tank above the drumtop, this-difference in level represents an appreciable area embracing asubstantial vol-- ume of water on one side of the axis 13, with a corresponding area on the other side of axis 13 and opposite thereto, devoid of water. Obviously, under such circumstances the volume discharged through an outlet positioned in this portion of the tank would be material-.

ly affected, a substantially greater or less amount than the measured quantity desired, being discharged, depending of course, upon the direction of inclination of the tank with respect to the outlet.

However, with the present improvements this water surface or area is reduced to a minimum at the discharge outlet by the presence of the drum 12. As is apparent, the drum occupies substantially the entire crosssectional area affected by the inclination of the water level, and previously referred to, save only a small annular space represented by 25. The area of this annular space 25 is obviously very small in comparison with the entire cross sectional area of the tank. Accordingly, when the level recedes below the top (dotted line) of the drum, the water seeks its own level in the small annular space 25 and the volume of water therein, which is affected by the inclination of the tank, is

but a small fractional part of the volume previously noted, so that the measured volume to be discharged is affected only by an inappreciable increment above or below the fixed standard, as the case may be. It is understood that the above description is applicable to any position of the drum.

It is thus seen that the effective water level of the measured volume is reduced to a minimum, so that, with the present improvements, the measured discharge from the tank is unaffected, in any material proportion, by unfavorable working conditions, such as grades, etc. Applicant has accordingly devised a measuring tank operable with equal accuracy under favorable or unfavorable conditions.

and one which may be universally applied to all apparatus adapted for the measuring of liquids.

Various modifications within the scope of the present improvements, will be apparent to those skilled in the art and may be adopted without departing from the'scope of the invention. H

I claim.

1. In a device of the character described,

ance therebetween and means for moving said drum.

3. A tiltable water measuring tank comprising an outer casing having a port, in the side thereof, an inner casing slidable in said tank and having limited clearance therewith, means for moving and setting said inner casing, all so constructed and arranged, that when the tank is discharged in inclined position the cross sectional area of the water affected by such incline is reduced to a minimum.

4:. A liquid measuring device for concrete mixers comprising a tank mounted on a movable base, a vessel within said tank, one portion of said vessel having a cross'sectional area slightly less than that of said tank whereby an annular area is provided between said members and discharge means for said tank-communicating with said annular area.

5. A liquid measuring device for concrete mixers comprising a tank, a drum within said tank, a portion of said drum having a cross sectional area slightly less than that of said tank whereby an annular area is provided between said members, and discharge means for said tank positioned in the side thereof and communicating with said annular area.

Witness my hand, this 25th day of April, 1928, county of Middlesex, State of New J erse I y JAMES E. BUSHNELL.

the combination of a water tankrhaving a port, a drum within said tank movable relative to said port for varying the discharge from the tank without aifecting the capacity thereof, said drum provided with pressure equalizing means and mechanism for varying the position of said drum.

2. In a device of the character described, the combination of water tank having a port. a drum having a perforate top suspended in said tank having its vertical walls spaced from said tank for effecting a minimum clear-

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