US3708121A

US3708121A - Apparatus for forming pulse jets of liquid

Info

Publication number: US3708121A
Application number: US00135120A
Authority: US
Inventors: J Hall; L Clipp
Original assignee: EXOTECH
Current assignee: EXOTECH; EXOTECH INC US
Priority date: 1971-04-19
Filing date: 1971-04-19
Publication date: 1973-01-02
Anticipated expiration: 1990-01-02

Abstract

Apparatus for forming pulsed jets of liquid. A pressure cylinder cooperates with a barrel inlet end to define a charge chamber. With the pressure cylinder in its normal position, the barrel inlet opening is blocked. Upon actuation of the device, the pressure cylinder is forced toward the barrel inlet end, applying pressure to charge material within the charge chamber, until the barrel outlet opening is unblocked and the pressurized charge material is expelled through the barrel as a pulsed jet.

Description

United States Patent 91 Hall em.

1541 APPARATUS FOR FORMING PULSE JETS OF LIQUID [75] Inventors: James M. Hall, Gaithersburg, Md.;

Louis L. Cllpp, McLean, Va.

[73] Assignee: Exotech Incorporated, Gaithersburg,

[22] Filed: April 19, 1971 [2]] Appl. No.: 135,120

521 U.S.Cl. ..239/102 511 Int. Cl. ..B05b 3/14 58 FieldofSearch ..239/99,101,102,329,456,

[56] 7 References Cited UNITED STATES PATENTS 2,912,169 11/1959 Peffer ..239/99 X 3,343,794 9/1967 Voitsekhowsky ..239/101 3,387,782 6/1968 Mizuno ..239/l01 X 51 Jan. 2, 1973 3,490,696 1/1970 Cooley ..239/l0l 3,520,477 7/1970 Cooley ....239/10I 3,521,820 7/1970 Cooley ..239/l0l Primary Examiner-M. Henson Wood, Jr.

Assistant Examiner-Edwin D. Grant Att0rneyMorton, Bernard, Brown, Roberts & Sutherland [57] ABSTRACT Apparatus for forming pulsed jets of liquid. A pressure cylinder cooperates with a barrel inlet end to define a charge chamber. With the pressure cylinder in its normal position, the barrel inlet opening is blocked. Upon actuation of the device, the pressure cylinder is forced toward the barrel inlet end, applying pressure to charge material within the charge chamber, until the barrel outlet opening is unblocked and the pressurized charge material is expelled through the barrel as a pulsed jet.

7 Claims, 12 Drawing Figures INVENTORS' M. HALL 8| CLIPP AT'I'OR 55 SHEET 1 BF 3 mm vv aanssaud k wi Wa a/h; 64mm NM Z? Hlll PATENTEDJAN 2191a PATENTED 21975 3.708.121

SHEEI 3 [IF 3 INVENTORS JAMES M. HALL 8:

LOUIS CLIPP ATTORNEYS .charge techniques have been used, but the expense and hazard associated with explosive materials have limited their use. Piston expulsion of liquid is utilized in apparatus in which a piston is actuated to contact a liquid charge, expelling the charge from the apparatus at a I high velocity and pressure. Such apparatus known heretofore have required considerable energy to create the necessary high velocity and pressure in the liquid jet.

The present invention is directed to an apparatus for generating pulsed jets of liquid in which a piston is actuated to move a pressure cylinder from its rest position in which the liquid outlet is blocked to a second position in which the liquid outlet is opened, permitting the liquid to discharge. During the time the cylinder is moving, pressure is built up on the liquid charge material, and when this pressure reaches the desired level, the outlet is opened to discharge the pulsed liquid jet at the desired velocity and pressure. As a consequence, the desired velocity and pressure are obtained with minimum expenditure of energy. Pressures of 300,000 to 500,000 p.s.i. are obtained with the present invention.

These and other aspects and advantages of the present invention are more apparent in the following detailed description and claims, particularly when considered in conjunction with the accompanying drawings in which like parts bear like reference numerals. In the drawings:

FIG. 1 is a fragmentary sectional viewof apparatus in accordance with the present invention;

FIG. 2 is a fragmentary view taken along line 2-2 of FIG. 1; j

FIG. 3 is a pressure-time diagram of the charge material within the apparatus as the apparatus is actuated.

FIGS. 4(a) and 4(b) illustrate the use of a deflection plate with apparatus in accordance with the present in vention;

FIGS. 5(a) and 5(b) illustrate an alternative means for deflecting the jet produced by apparatus of this invention;

FIGS. 6(a) and 6(b) illustrate apparatus of this invention designed to produce multiple jets;

FIG. 7 illustrates apparatus of this invention includ ing means for flushing the jet nozzle to prevent plugging; and

FIGS. 8(a) and 8(b) illustrates apparatus of this invention designed for underwater use.

As depicted in FIG. 1, a preferred embodiment of apparatus in accordance with the present invention includes an elongated cylindrical housing 10 having an elongated barrel 12 positioned within it. Barrel 12 includes a middle portion l4of an enlarged diameter which fits snugly within housing 10, an elongated forward portion 16 of a relatively small diameter, and a rear portion 18 also of a small diameter substantially the same diameter as that of forward portion 16. Axial bore 20 passes through barrel l2 and serves as an acceleration path for pulsed jets of liquid. Preferably, bore 20 tapers from a larger diameter in rear portion 18 to a smaller diameter in forwardl portion 16 so that as liquid charge travels through bore 20 the charge velocity and pressure increase. End cap 22 is fastened to the rearward end of barrel 12, for example, by means of bolt 24.

A radial bore 26 passes through housing 10 and into central portion 14 of barrel 12. Within central portion 14 radial bore 26 intersects longitudinal bore 28 which passes through rear portion 18 of barrel l2 and communicates with bore 30 through end cap 22. For a small distance within barrel 12 and cap 22 and adjacent the interface of those two components bore 28 and 30 have a slightly increased diameter within which is positioned check valve 32. Bushing 34 retains check valve 32 in this area. Bore 20 does not pass longitudinally through cap 22, but instead, as seen in FIG. 2, at the intersection of barrel l2 and cap 22, bore 20 intersects with radial bore 36 that passes completely through cap 22.

Pressure cylinder 38 includes a forward portion 40, encircling rearward portion 18 of barrel l2, and a rearward portion 42 enclosing cap 22 but leaving a small chamber 44 to the rear of cap 22. Chamber 44 has a diameter slightly greater than the diameter of cap 22 and barrel rearward portion 18. This increased diameter extends forward about cap 22 to a point about at the longitudinal midpoint of cap 22 at which location chamber 44 ends and pressure cylinder 38 contacts cap 22 at circumference 45, usually through an intermediate layer of fluid. Pressure cylinder 38 does not contact central portion 14 of barrel 12 but instead a small chamber 46' is present between pressure cylinder 38 and central portion 14. Preferably, chamber 46 has a longitudinal dimension slightly smaller than the longitudinal dimension of chamber 44 to avoid direct contact at cap 22. Thus, pressure cylinder 38 is able to move from its rearward position, as depicted in FIG. 1, to a forward position in which forward portion 40 of pressure cylinder 38 contacts central portion 14 of barrel 12 before rearward portion 442 can contact cap 22. Pressure cylinder 38 is biased to its rearward position as depicted in FIG. 1 by means such as spring 50 which is engaged between housing 10 and pressure cylinder 38. Seal 48 is positioned between rearward portion 18 of barrel 12 and forward portion 40 of pressure cylinder 38 to provide a substantially fluid-tight seal. Seal 48 comprises a rigid, non-resilient member 47, such as metal, which sealingly engages portion 18, a resilient member 49 and a chamfer ring 51. Member 47 has a lip 47' and resilient member 49 rests on this lip so that it does not engage portion 18. In use, pressure is exerted upon member 49 by fluid in the interface between portion 18 and portion 40 which passes through gap 49' and, as a consequence, resilient member 49 exerts a force on member 47, particularly lip 47', to seal member 47 against portion 18. Camfer ring 51 prevents extrusions of member 49 into the interface between member 47 and portion 40.

Forward portion 16 of barrel 12 is encircled by cylinder 52 which has an outer diameter substantially the same as central portion 14. Retainer 54 retains barrel l2 and cylinder 52 within housing 10.*Barrel 12 is additionally keyed within housing and cylinder 52 to prevent rotation.

Piston 56 is positioned behind pressure cylinder 38 and is surrounded by jacket 58 within which it fits snugly but slidingly. Housing 10 has on its outer surface adjacent jacket 58 an elongated recess 60, and retainer 62 within recess 60 maintains housing 10 and jacket 58 together while permitting longitudinal movement therebetween from the position of FIG. 1 to a position in which retainer 62 is at the rearward end 64 of recess 60.

When it is desired to generate pulsed liquid jets, liquid charge material is introduced through inlets or bores 26 and 28. The pressure of this charge causes it to pass check valve 32 and to flowthrough bore 30 into charge chamber 44. Piston 56 is then actuated to impact against pressure cylinder 38. The pressure cylinder moves forward, applying pressure to the charge material within chamber 44. FIG. 3 depicts this pressure on the charge within chamber 44 as a function of time. Pressure cylinder 38 is dimensioned so that as it moves forward, thereby increasing the pressure on the charge in zone 44, circumference 45 passes bore 36 as the pressure is at its optimum value, depicted at point 66 in FIG. 3. Once circumference 45 has cleared bore 36, the charge material enters barrel bore 20, so that the pressure on the charge material reaches a peak and then drops off as illustrated in FIG. 3. The charge material is then expelled from barrel 12 as a pulsed liquid jet. Pressure cylinder 38 continues to move forward against the bias of spring 50 until the pressure cylinder contacts central portion 14 of barrel 12. This impact is transmitted through central portion 14 and cylinder 52, and so the forward end of cylinder 52 also impacts against the material at which the pulsed liquid jet is directed. This additional impact causes a further fracturing of the material. The forward motion of barrel l2 and cylinder 52 carries with these components housing 10 which moves with respect to jacket 58 until rearward end 64 of groove 60 is against retainer 62.

A small amount of charge material is forced backward through check valve 32 just prior to check valve 32 closing. This charge flow can be adjusted so that the volume of charge material within zone 44 is uniform for each firing of the apparatus. Piston 56 can be actuated by any suitable means such as an explosive charge, release of a pressurized fluid, release of a cooked spring, etc. If desired, piston 56 and pressure cylinder 38 can be formed as one piece.

FIGS. 4(a) and (b) and 5(a) and (b) illustrate two embodiments of this invention having attachments for angling the fluid jet produced by the apparatus of this invention. In each embodiment, the device for producing the fluid jet, generally designated by reference numeral 200, may be a device such as illustrated in FIG. 1. As shown in FIGS. 4(a) and (b), a deflection plate 201 is attached to the end of device 200 by a support mechanism 202. This deflection plate is arranged at an angle a to the fluid jet and contains slot 204. When using a deflection plate 201, the fluid jet will be deflected in the form of a spray. The width of the spray is determined by the width of slot 204 and may be controlled to provide a jet suitable for cutting a slot. Angle a may be as great as 15 to FIGS. 5a and 5b illustrates an alternative embodiment in which cap 208 is attached to the end of device 200. In this embodiment cap 208 has a number of bores 210 arranged therein in conical fashion about a central opening 212 which is arranged co-axially with the expulsion bore 20 in device 200. In this embodiment as the jet of water passes through cap 208 it is deflected in bore 212 to pass through bores 210. The number of bores 210 can vary from one to any number, e.g., six as shown.

FIGS. 6(a) and (b) illustrate an embodiment of the device identical with FIG. I accept for the inclusion of a plurality of expulsion bores 20. As shown in FIG. 6( a) there are two bores 36 passing through end cap 22 and each bore 36 has two expulsion bores 20 perpendicular to and interconnected therewith.

FIG. 7 illustrates another embodiment of the apparatus of this invention and differs from FIG. 1 in providing a means for flushing expulsion bore 20 to prevent plugging. In this embodiment end cap 22 of FIG. I is substantially elongated as shown by end cap 122 in FIG. 7. Additionally,

chambers

144 and 146, which correspond to

chambers

44 and 46 in FIG. 1, are substantially enlarged. The device of FIG. 7 operates the same as the device of FIG. 1, described above, except that in its end position pressure cylinder 38 and seal 48 have moved to a third position to the right of bore 136 so that chamber 146 is connected through bore 136 with bore 120. Chamber 146 has connected therewith fluid pressure line 175 which contains check valve 177. Check valve 177 operates upon a reduced pressure in chamber 146 to permit the introduction into this chamber of fluid under pressure, e.g., air or water. Fluid passes through bore 136 to flush bore 120. As pressure cylinder 38 returns to its normal position, the pressure in chamber 146 will build up to close check valve 177. The pressure in chamber 146 is balanced to allow return of pressure cylinder 38 to a position for operation of the jet valve 32.

FIGS. 8(a) and (b) illustrate a further embodiment of this device designed for operation under water. In this device cylinder 52 which surrounds portion 16 of barrel 12 is elongated to form chamber forward of portion 16. An air pressure line 220 is connected'with chamber 80. In operation under water, chamber 80 is always maintained at a sufficient pressure to prevent water, or other fluid media, from entering chamber 80. Cylinder 52 may rest against the surface to be worked and impact this surface at the same time as the pulsed liquid jet. FIG. 8 also illustrates the attachment of breaking tools 222 which may be of any conventional shape. Breaking tools 222 causes further fracturing of the material being enclosed upon by the additional impact of cylinder 52. The end of portion 16 may be positioned such that the fluid jet must penetrate one to three inches of water but greater distances substantially reduce the velocity of jet.

Although the present invention has been described with reference to preferred embodiments, numerous modifications and rearrangements could be made and still the result would be within the scope of the invention.

What is claimed is:

1. Apparatus for forming pulsed jets of liquid comprising:

an elongated cylindrical expulsion barrel having an inlet end, an outlet end and at least one longitudinal bore therethrough from the inlet end to the outlet end;

an end cap having a forward face connected to said expulsion barrel inlet end, having a rear face, and having at least one radial bore therethrough communicating with said expulsion barrel longitudinal bore;

bias means;

a pressure cylinder encircling said expulsion barrel inlet end and said end cap and under urging of said bias means normally assuming a first position in which said pressurecylinder cooperates with said end cap to define a charge chamber extending behind said end cap rear face and around said end cap to a point intermediate said radial bore and said end cap rear face and capable of movement to a second position in which said charge chamber extends around said end cap to a point forward of said radial bore;

said expulsion barrel and said end cap having an inlet opening therethrough communicating with said charge chamber;

a check valve within the inlet opening for permitting charge flow through the inlet opening into the charge chamber while substantially preventing charge flow from the charge chamber throughthe inlet opening; and

actuating means for actuating said pressure cylinder to move said pressure cylinder against the urging of said bias means toward said end cap, thereby applying pressure on charge material within the charge chamber until the pressure cylinder reaches the second position and charge is expelled out the expulsion barrel as a pulsed liquid jet.

2. Apparatus as claimed in claim 1 further comprising a further cylinder encirclingly engaged about said expulsion barrel, a jacket slidingly engaging said actuating means and said pressure cylinder, and retaining means for retaining said jacket relative to said expulsion barrel and said further cylinder while permitting limited longitudinal movement therebetween, whereby upon actuation of said pressure cylinder, said expulsion barrel and said further cylinder move longitudinally with respect to said jacket.

3. Apparatus as claimed in claim 1 further comprising flushing means for flushing said expulsion barrel after expelling of the pulsed liquid jet.

4. Apparatus as claimed in claim 3 wherein the flushing means comprises said pressure cylinder and expulsion barrel which cooperate to form a second chamber, said pressure cylinder having a third position assumed upon the application of pressure on the charge material following the first and second position and expulsion of the liquid jet in which third position the second chamber communicates through said radial bore with the expulsion barrel and means for supplying pressure fluid to said second chamber when the pressure cylinder is in said third position.

5. Apparatus as claimed in claim 1 further comprising a deflection plate attached to the outlet end of said expulsion barrel at an angle to the longitudinal bore.

6. Apparatus as claimed in claim 1 further comprising a cap attached to the outlet end of the expulsion barrel, said cap containing at least one bore therein interconnecting with the longitudinal bore at an angle to thelaxis of said longitudinal bore.

. Apparatus as claimed in clanm 1 wherein said barrel contains a plurality of longitudinal bores communicating with the radial bore.

Claims

1. Apparatus for forming pulsed jets of liquid comprising: an elongated cylindrical expulsion barrel having an inlet end, an outlet end and at least one longitudinal bore therethrough from the inlet end to the outlet end; an end cap having a forward face connected to said expulsion barrel inlet end, having a rear face, and having at least one radial bore therethrough communicating with said expulsion barrel longitudinal bore; bias means; a pressure cylinder encircling said expulsion barrel inlet end and said end cap and under urging of said bias means normally assuming a first position in which said pressure cylinder cooperates with said end cap to define a charge chamber extending behind said end cap rear face and around said end cap to a point intermediate said radial bore and said end cap rear face and capable of movement to a second position in which said charge chamber extends around said end cap to a point forward of said radial bore; said expulsion barrel and said end cap having an inlet opening therethrough communicating with said charge chamber; a check valve within the inlet opening for permitting charge flow through the inlet opening into the charge chamber while substantially preventing charge flow from the charge chamber through the inlet opening; and actuating means for actuating said pressure cylinder to move said pressure cylinder against the urging of said bias means toward said end cap, thereby applying pressure on charge material within the charge chamber until the pressure cylinder reaches the second position and charge is expelled out the expulsion barrel as a pulsed Liquid jet.

6. Apparatus as claimed in claim 1 further comprising a cap attached to the outlet end of the expulsion barrel, said cap containing at least one bore therein interconnecting with the longitudinal bore at an angle to the axis of said longitudinal bore.

7. Apparatus as claimed in claim 1 wherein said barrel contains a plurality of longitudinal bores communicating with the radial bore.