US2578821A - Fluid projecting apparatus - Google Patents

Description

Dec. 18, 1951 M. MCBRIDE 2,578,821

FLUID PROJECTING APPARATUS Filed Dec. 9, 1946 IN V EN TOR. L EW/S M. M BR/DE A T TORNEYS Patented Dec. 18, 1951 UNITED STATES PATENT OFFICE 2,578,821 more raoasc'rmc APPARATUS Lewis M. McBride, Arcadia, Calif.

. ApplicatiomDec'ember 9,1946, Serial No.7:15;050 11 Claims. (01. air-s9) This invention relates to a fluid projecting apparatus and more .particularly to :adevioe for the projection of a liquid-or the suspensionof a solid in a liquid, at a high forward and rotational velocity.

In. the spraying or 'proiecting of liquids'such as insecticides, lacrimators, andthe like or of suspensions of solid finelydivided toxic-ornon-toxic agents in suitable carrying liquids, use is commonly made of an auxiliary source of pressure fluid such as various compressed gases to furnish the projecting force. These auxiliary pressure fluids are conveniently introduced to a reservoir containing the liquid or suspension to be discharged thereby forcing the same through an eduction tube and a discharge nozzle.

In U. S. Patent 1,740,471 I described a fluid pro-- iecting apparatus of this type in which a pressure operating fluid such as compressed air, oxygen, carbon dioxide or the like was employed to discharge the liquid or suspension from the projecting apparatus. This device operated on a differential pressure principal which permitted the introductionof a certainamount of the pressure operating fluid into the discharging stream to-accelerate and disperse the latter. This differential pressure was obtained-by allowing a portion of the'pressure operating fluid to by-pass the reservoir of the projecting device vand pass through an orifice directly into the discharging stream within the "eductiontube. The pressure differential induced in this device was a function of the size-of this by-pass orifice, which was predetermined as a function-of the internal diameter of the eduction tube and the character 'of the pressure operating fluid.

A limitation inherent in the above described fluid projecting apparatus was the absence of means for controlling the pressure differential. This limitation rendered the operation with various types of pressure fluids variable inasmuch as the character of Various ones of such fluids, as for example, oxygen, compressed air, liquid carbon dioxide, etc., differs and the pressure at which they are stored is not uniform. Further it has been found that as the pressure of any type of pressure fluid falls, due to the partial exhaustion of .the pressure in the container the operation of the fluid pro-jectingdevice varies as a result of the fixed size of this bypass orifice. Similar variation in operation is encountered where the liquid in the .reservoir is depleted, which reduction causes a corresponding increase in the volume occupiedby the pressure fluid within the reservoir resulting in a disproportionate exhaust of the pressure fluid through the bypass naturally results from such a variation in the pressure differential equilibrium." Further no means were provided in the above described apparatus for closing off the eduction tube and bypass orifice so as to prevent undesirable leakage when the pressure of the pressure fluid dropped to an inoperative level or when the device was not in use.

It is an object therefor of the present invention to provide a fluid projecting device which operates automatically and uniformly regardless of the variations in the pressure-of the motivating fluid or in the volume of space in the apparatus occupied by the motivating fluid.

It is an additional object of the invention to provide a fluid projecting apparatus in which the ejection of liquid is automatically prevented when the now of pressure fluid is stopped and which will not leak when not in :use regardless of its position.

These and other objects of the invention are accomplished according to the present invention by the provision of a difierential pressure type liquid projecting apparatus in which the differential pressure equilibrium is automatically maintained and in which aliquid flow through an eduction tube and nozzle-is automatically prevented when the driving pressure falls below a predetermined value.

The apparatus whereby the foregoing ends are accomplished comprises in its simplest embodiment .a source of pressure, a liquid reservoir in communication therewith, means .for forcing the gas from the pressure source to flow into the liquid reservoir and to thereby force the liquid in the, reservoir out through an eduction tube and nozzle in association with the reservoir and a bypass orifice through which a portion of the gas from the pressure source flows directly into the eductio'n tube, at a point above the liquid level in the reservoir and a spring loaded regulating valve disposed in theeduction tube adjacent to the orifice inlet whereby the fl'ow from the reservoir and the flow -of gas fr'om the pressure source through the aforementioned bypass orifice is controlled by the :tension ex erted on the spring loaded check valve.

The invention may be :more clearly understood from the following detailed description. thereof taken in relation to the accompanying drawing in which:

Fig. 1 is a side elevation of the fluid projecting apparatus in association with the pressure source;

Fig. 2 is a sectional elevation of the fluid projecting apparatus;

Fig. 3 is a plan view of the apparatus;

Fig. 4 is a side elevation of a modified form of the apparatus showing the reservoir and pressure source in different relationship than that shown in Fig. 1; and

Fig. 5 is a fragmentary sectional elevation of the apparatus of Fig. 4.

In Fig. 1 the reservoir I is shown afiixed to the pressure source, or cylinder II by means of the connecting nipple I2 provided with the set screws I3 and I4.

The pressure source I I may be of any conventional type and may be provided with substantially any non-toxic gas under pressure such as air, carbon dioxide, nitrogen, or the like, or may be filled with a liquid of high vapor pressure such as liquified carbon dioxide or the like. Most conveniently the pressure source I is of the type provided with an integral needle valve I at the top thereof to which the reservoir Ill may be affixed by means of the nipple I2. A flow of gas from the source II to the reservoir may be controlled by the needle valve I5 by the simple twisting of the reservoir and gas source in relationship to each other.

Also in Fig. 1 the nozzle I6 is shown projecting from the cap member afiixed to the reservoir I0. The cap member I! is provided with a projecting collar I8 flattened on two sides as shown in Figs. 2 and 3 to permit the engagement thereof with a suitable wrench.

The liquid insecticides, lacrimators, irritants or the like or the suspension of powdered insecticides, lacrimators, irritants or the like which are adaptable to usage in the projecting apparatus of my invention can normally be purchased in cylindrical containers such as the container 25 shown in Fig. 2 which is a sectional elevation of the projecting apparatus with the pressure source I I eliminated. As shown in Fig. 2 such a container 25 is placed Within the reservoir I0 with the bottom thereof closed and the cap removed. The reservoir III is of such dimensions as to provide a relatively small annular space 26 between the walls of the container 25 and of the reservoir I0. The bottom member 28 is afiixed to the reservoir II] by suitable threads or the like and is provided with the aforementioned nipple I2 whereby the valve I5 of the pressure cylinder I I as shown in Fig. 1 may be aflixed to the reservoir. The bottom closure 28 is provided with a passageway 29 communicating between the pressure source and the interior of the reservoir I0.

Disposed within the reservoir I0 and abutting against the closure member 28 is the helical spring 30 which exerts an upward force on the container 25 so as to cause the lip 3| of the container 25 to abut against the circular gasket 32 provided in the cap member so as to form a seal therewith.

Gas released from the cylinder I I by the twisting of the reservoir It] with relation to the pressure cylinder and thereby opening the valve I5, flows through the passageway 29 and upwardly around the container 25 through the annular space 25.

The cap I1 is provided with threads 33 which engage the threads 34 of the reservoir I0. As

shown in Fig. 2 the cap IT projects within the reservoir I0 an appreciable distance and the projection of the cap is provided with a circumambient groove 36. Projecting radially inwardly from the groove 36 is a bore 38 which is in communication with the upper opening of the container 25 by means of the perpendicular bore 39. The lower face of the cap IT is adapted to receive an eduction tube 40 afiixed thereinto by means of the threads 4| Or the like. The upper face of the cap I1 is adapted to receive the nozzle I6 hereinafter more fully described. A passageway 44 is provided in the cap member I! communicating between the upper end of the eduction tube 40 and the lower end of the nozzle I6. The passageway 44 may be considered and is so considered hereinafter as an integral part of the eduction tube 40.

A bypass orifice 45 is provided in communication with the radial bore 38 and the passageway 44 and is of smaller diameter than the bore 39. communicating between the bore 38 and the bore and the upper opening of the container 25.

Projecting radially and diametrically opposite to the above mentioned bore 38 is a bore 45 threaded at the outer end to engage a set screw 48 which controls the compressive force applied to a helical spring 50 residing within the bore 46. The helical spring 50 exerts a compression force on a ball valve 5| residing in the passageway 44 at the point of entrance of the orifice or bypass tube 45. The ball valve 5| is adapted to seat in its closed position against the orifice 45 and against the opening of the eduction tube 40. Thus when no pressure or only a small amount of pressure is supplied to the reservoir through the passageway 29 of the nipple I2 the compressive force of the spring 50 is maintained sufficiently high to cause the ball valve 5| to seat as above described and thereby prevent the flow of gas through the orifice 45 and the flow of liquid through the eduction tube 40.

By varying the position of the set screw 48 and thus the compressive force exerted by the spring 50 on the check valve 5| the apparatus can be caused to shut off at any predetermined pressure and further the pressure diiferential existing between the gas flowing through the orifice 45 and the gas flowing into the container 25 may be automatically controlled so as to be substantially constant regardless of variations in pressure of the pressure source or pressure motivating fluid. The advantages accruing from the ability to maintain such a constant differential pressure equilibrium and further to prevent the flow of any fluid or any gas or liquid below a predetermined driving pressure are immediately obvious. By virtue of this feature of the apparatus the liquid spray may be maintained substantially constant regardless of variation of pressure in the pressure source and may be stopped completely and leakage prevented when the pressure in such source falls below a level sufiicient to unseat the ball valve 5|. This minimum pressure required to unseat the regulating valve 5| is a function of the compression of the spring 50 by the set screw 48 and may be readily adjusted ingaccordance with the type of pressure fluid to be employed and other variable conditions. v

The nozzle I6 is provided with a helical core 54. To preclude the passage of the liquid discharged from the reservoir centrally through the nozzle I6 the core is formed with a diameter slightly in excess of the internal radius, of the nozzle. Thus the helical core prevents any straight flow through the tube I6 and provides for ejection of the suspension from the nozzle with a spiral as well as a linear velocity. Thus as the jet is issuing from the nozzle it'has three motions: linear and rotational or helical as well as the motion due to the expanding and rotating jet which is spiral at any given point, hence this motion could be termed a helical-spiral-velocity.

As an example the nozzle It may be rified with two or three turns per inch of the helical core 54. When using carbon dioxide as the source of pressure linear velocity of the gas driven liquid through the nozzle will be approximately 1000 feet per second. Hence, the rotational velocity will be'between 24,000 and 36,000 R. P. M. Thus the liquid is dischargedfrom the nozzle at a high linear and rotational velocity, affording the greatest possible range with the least loss and with practically no dispersion of the irritant agent in the vicinity of the operator.

In Fig. 3 a plan view-of the apparatus is shown. In this figure it is seen that thecap I? is provided with the threads 33 and the circumferential groove 30 from which the radial bore or passageway ;38 and the orifice or bypass '45 project inwardly. Diametrically opposite the bore '38 is the radial bore -46 in which is disposed the set screw '48 maintaining the helical spring 50 against the regulating valve 5i shown in Fig. 2.

Having described the structural details of this embodiment of the invention its operation is as follows:

The pressure receptacle I I is charged with air or an inert gas or a liquid of high vapor pressure to approximately 1000 lbs. per square inch and the container 25 containing the desired liquid to be projected is inserted in the reservoir III. The reservoir I is affixed to the valve I of the pressure cylinder II by means of the nipple arrangement I2 and is held in position by the set screws I3 and I4. These set screws I3 and I4 permit the twisting of the reservoir III with relation to the pressure cylinder II without exerting force on the threads of the nipple,'i. e. without unscrewing or excessively tightening the reservoir with relation to the pressure cylinder.

Upon exerting a small twisting force on either the reservoir or the pressure cylinder the needle valve I5 positioned in the upper portion of the cylinder I I is opened and the gas escaping therefrom flows through the passageway 29 into the lower portion of the reservoir I0, passes around the outside of the container 25 in the annular space 26 and passes upwardly past the upper end of the container 25, and the gasket 32, into the circumferential groove 36 in the cap member II. From this circumferential groove 38 the gas is forced through the radial "bore 38 and the vertical bore 39 into a liquid container 25, causing the discharge of liquid from the con tainer through the eduction tube 40 and the nozzle IS. A portion of the gas fiowin'g through the bore 38 proceeds'directly through the bypass 4 5 intothe e'duction tube. Thus the liquid will be discharged providing that the combined force acting upon the valve 5| from the gas flowing through the orifice 45 and the liquid in the eduction tube 40 is sufficient to unseat the valve. The effect of the gas bypassing the container 2 5 through the orifice or'bypass 45 is to accelerate the velocity ofliquid flow through the nozzle. I6

6 and project samewith a high forward and rotat iona1velocity.'-

Another modification ofthe apparatus of the invention is shown in elevation inFig. 4 and in a frag-mentary sectional elevation in Fig. 5. This apparatus differs from that heretofore described in the provisionof the pressure cylinder I I communicating with the side of the reservoir I0 rather than through the bottom thereof. In this apparatus the container rests on the spring supportedon the bottom 28 of the reservoir I0. The bottom 28 may be permanently afiixed to the reservoir. either by threads as shown or by welding or the like. A support means 60 may be clamped to the pressure source II so as to support the reservoir I0 in the proper relationship to thepressure source II. The cylinder II is provided with the needle valve t5 and the control of the flow of pressure fluid I-I into the reservoir I0 may be accomplished by the simple twisting of the cylinder II as above described.

In this apparatus as shown in Fig. '5 the nipple communicating between the reservoir and the cylinder 'II constitutes an integral part of the side of the reservoir III. This nipple 32 communicates directly with the bore '38 proceeding radially from the circumferential groove 36 and thus provides for the same action as described in relation to the above described apparatus.

The gas flowing through the bore 38 is divided a part flowing through the bore 39 into the top of the container 25 which is forced against the gasket 32, by the spring 30, and a part flows through thebypass bore 45 directly into the eduction. tube 40. Here again the operation of the device is dependent upon the compressive force exerted by the spring 50 on the ball valve 51 which in turn is a function of "the tension placed on the spring by the set screw 48 disposed in the radial bore hole 46.

As shown in Fig. 1,- there is provided the tube 6 1 communicating between the needle valve I5 of the pressure source I I and the nipple 62 forming an integral part of the reservoir ID. The tube 6 is affixed to the needle valve I5 by means of the coupling 65 and the nipple 62 by means of the coupling 66.

Itwill be immediately apparent that many mechanical'variations in the liquid projecting apparatus of the invention may be made without departing from the scope of the foregoing description or of the following claims.

Iclairn:

1. A liquid projecting apparatus comprising a cylindrical reservoir provided with a cap member and a closure at its lower end, said closure forminga nipple, a source of gas under pressure adapted to engage with said nipple, means for affixing said source to said nipple to permit the exertion of a propelling force'betwe'en said source of gas under pressure and said reservoir, a liquid container open at its upper end and closed at its lower end positioned within said reservoir, so as .to provide an annular space between said container and said reservoir, a helical spring positioned in said reservoir between the bottom thereof and the bottom of said liquid container so as to force said liquid container to abutagainst a gasket member provided in saidcap member, said cap member being further provided with a circumferential slot, a pair of diametrically opposed radial bores projecting inwardly from said circumferential slot, a vertical bore communicating betweenthe upperendof said container and one of said radial bores, an orifice communicating between said last mentioned radial bore and an eduction tube projecting through said cap member and terminating below the surface of the liquid in said container, a nozzle projecting from said cap member and in communication with said eduction tube, and a regulating valve disposed within said eduction tube adjacent to said orifice.

2. An apparatus according to claim 1 wherein said regulating valve is maintained within said eduction tube by means of a helical spring disposed within the said other of said radial bores.

3. An apparatus according to claim 2 wherein said regulating valve is maintained within said eduction tube by means of a helical spring disposed within the said other of said radial bores, the compression force of said helical spring being variably responsive to the setting of a set screw disposed within said other of said radial bores.

4. A liquid projecting apparatus comprising a reservoir provided with a cap member and a closure at its lower end, a liquid container open at its upper end and closed at its lower end positioned within said reservoir, a helical spring positioned in said reservoir between the bottom thereof and the bottom of said liquid container so as to force said liquid container to abut against a gasket member provided in said cap member, said cap member being further provided with a circumferential slot, a pair of diametrically opposed radial bores projecting inwardly from said circumferential slot, a vertical bore communicating between the upper end of said container and one of said radial bores, an orifice communicating between said last mentioned radial bore and an eduction tube projecting through said cap member and terminating below the surface of the liquid in said container, a nozzle projecting from the said cap member and in communication with said eduction tube, a regulating valve disposed within said eduction tube adjacent to said orifice, a nipple member located in the wall of said reservoir in communication with said first mentioned radial bore, and a source of gas under pressure adapted to engage with said nipple.

5. An apparatus according to claim 4 wherein said regulating valve is maintained within said eduction tube by means of a helical spring disposed within the said other of said radial bores.

6. An apparatus according to claim 4 wherein said regulating valve is maintained within said eduction tube by means of a helical spring disposed within the said other of said radial bores, the compression force of said helical spring being variably responsive to the setting of a set screw disposed within said other of said radial bores.

'7. A liquid projecting apparatus comprising a reservoir provided with a cap member and a closure at its lower end, a liquid container open at its upper end and closed at its lower end positioned within the reservoir, a helical spring positioned in the reservoir between thebottom thereof and the bottom of the liquid container, so as to force the liquid container to abutagainst a gasket member'provided in the cap member, the cap member being further provided with a circumferential slot, a pair of diametrically opposed radial bores projecting inwardly from said circumferential slot, a vertical bore communicating between the upper end of the container and one of the radial bores, a restricted orifice communicating between thelast mentioned radial bore a closure at its lower end, said closure forming a nipple, a source of gas under pressure adapted to engage with the nipple, a liquid container open at its upper end and closed at its lower end positioned within the reservoir, a helical spring positioned in said reservoir between the bottom thereof and the bottom of said liquid container so as to force said liquid container to abut against a gasket member provided in the cap member, said cap member being further provided with a circumferential slot, a pair of diametrically opposed radial bores projecting inwardly from said circumferential slot, a vertical bore communicating between the upper end of said container and one of said radial bores, a restricted orifice communicating between said last mentioned radial bore and an eduction tube projecting through said cap member and terminating below the surface of the liquid in said container, a nozzle projecting into the cap member and in communication with the eduction tube, a regulating valve disposed in said eduction tube adjacent the orifice.

9. A liquid projecting apparatus comprising a reservoir provided with a cap member and a closure at its lower end, a liquid container open at its upper end and closed at its lower end positioned within the reservoir, a helical spring positioned in said reservoir between the bottom thereof and the bottom of said liquid container so as to force said liquid container to abut against a gasket member provided in the cap member, said cap member being further provided with a circumferential slot, a pair of diametrically opposed radial bores projecting inwardly from said circumferential slot, a vertical bore communicating between the upper end of said container and one of said radial bores, a restricted orifice communicating between said last mentioned radial bore and an eduction tube projecting through said cap member and terminating below the surface ofthe liquid in said container, a nozzle projecting into the cap member and in communication with the eduction tube, a regulating valve disposed in said eduction tube adjacent the orifice, a nipple member located in the wall of said reservoir in communication with said first mentioned radial bore, and a source of gas under pressure adapted to engage with said nipple.

10. A liquid projecting apparatus comprising a reservoir provided with a cap member and a closure at its lower end, a liquid container open at its upper end and closed at its lower end positioned within the reservoir, a helical spring positioned in the reservoir between the bottom thereof and the bottom of the liquid container, so as to force the liquid container to abut against a gasket member provided in the cap member, the cap member being further provided with a circumferential slot, a pair of diametrically opposed radial bores projecting inwardly from said circumferential slot, a vertical bore communicating between the upper end of the container and one of the radial bores, a restricted orifice communicating between the last mentioned radial bore and an eduction tube projecting through the cap member and terminating below the surface of the liquid in the container, a nozzle projecting through the cap member and in communication with the eduction tube, a ball in the eduction tube seating against the orifice and adapted to close the orifice and tube and spring loaded against the orifice, a source of gas under pressure, and means communicating between the source of gas under pressure and said one of said radial bores.

11. A liquid projecting apparatus comprising a reservoir provided with a cap member and a closure at its lower end, a liquid container open at it upper end and closed at its lower end positioned within the reservoir, a helical spring positioned in the reservoir between the bottom thereof and the bottom of the liquid container, so "as to force the liquid container to abut against a gasket member provided in the cap member, the cap member being further provided with a circumferential slot, a pair of diametrically opposed radial bores projecting inwardly from said circumferential slot, a vertical bore communicating between the upper end of the container and one of the radial bores, a restricted orifice communicating between the last mentioned radial bore and an eduction tube projecting through the cap member and terminating below the surface 3 of the liquid in the container, a nozzle projecting through the cap member and in communication with the eduction tube, a ball in the eduction tube adjacent the orifice adapted to seat against the orifice and in the eduction tube to prevent liquid flow through the tube and gas flow through the orifice, a helical spring in the other of said radial bores bearing against the ball, a set screw in the outer end of the last mentioned bore holding the spring in the bore and providing means for adjusting the spring tension on the ball, a source of gas under pressure, and means communicating between the source of gas under pressure and said one of said radial bores.

LEWIS M. MCBRIDE.

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

UNITED. STATES PATENTS Number Name Date 20 495,249 Hugershofi Apr, 11, 1893 814,820 Wood Mar. 13, 1906 1,740,471 McBride Dec. 24, 1929 1,876,644 Downs Sept. 13, 1932 2,079,587 Aronson May 11, 1937 25 2,120.948 Beck June 14, 1938 2,123,755 Tear et al July 12, 1938 2,167,866 Bennett Aug. 1, 1939 2,195,554 Beardsley Apr. 2, 1940 FOREIGN PATENTS 0 Number Country Date 696,508 France Aug. 10, 1931 794,018 France Feb. 6, 1936

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