US3796371A

US3796371A - Jet piercing device

Info

Publication number: US3796371A
Application number: US00269834A
Authority: US
Inventors: N Taylor; C Noren; B Lundqvist; O Meyer
Original assignee: Atlas Copco AB
Current assignee: Atlas Copco AB
Priority date: 1972-05-19
Filing date: 1972-07-07
Publication date: 1974-03-12
Anticipated expiration: 1991-03-12
Also published as: DE2323558A1; DE2323558B2; JPS4942503A; ZA732964B; DE2323558C3

Abstract

In a jet piercing device incorporating a liquid chamber wherein ultra high pressure is generated, a liquid is forced out through a nozzle having outlet means at the end of a conically contracted passage. The restricted area of flow of the outlet means is distributed and orientated in a direction transverse to the feeding direction of the nozzle so that a wide slot can be cut in the material worked upon with a low consumption of energy. The area of flow of the nozzle may be defined by a single flattened outlet or may be divided into two or more outlets extending in spaced relation longitudinally of the nozzle. The width of the pierced slot is adjusted by turning the nozzle relative to the feeding direction thereof.

Description

Taylor et a1.

JET PIERCING DEVICE Inventors: Nicholas Simon Hall Taylor,

Saltsjobaden; Bo Claes Ingmar I undgvist, Stockholm; Olaf Meyer, Sollentuha; Carl Anders Norn, Saltsjo-Boo, all of Sweden Atlas Copco Aktiebolag, Nacka, Sweden Filed: July 7, 1972 Appl. No.: 269,834

Assignee:

#1 Foreign Application Priority Data May 19, 1972 Sweden 6555/72 References Cited UNITED STATES PATENTS 7/1949 Ralph 239/184 X 7/1969 Connolly 299/17 X 1/1961 Foreman 239/597 Mar. 12, 1974 3,343,794 9/1967 Voitsekhovsky 23 9/10] 3,490,696 l/l970 Cooley 239/101 3,521,820 7/1970 Cooley 239/101 3,520,477 7/1970 Cooley 239/101 Primary ExamiherAllen N. Knowles Attorney, Agent, or FirmEric Y. Munson [5 7] ABSTRACT In a jet piercing device incorporating a liquid chamber wherein ultra high pressure is generated, a liquid is forced out through a nozzle having outlet means at the end of a conically contracted passage. The restricted area of flow of the outlet means is distributed and orientated in a direction transverse to the feeding direction of the nozzle so that a wide slot can be cut in the material worked upon with a low consumption of energy. The area of flow of the nozzle may be defined by a single flattened outlet or may be divided into two or more outlets extending in spaced relation longitudinally of the nozzle. The width of the pierced slot is adjusted by turning the nozzle relative to the feeding direction thereof.

6 Claims, 7 Drawing Figures 13 14 H 1 I I5 minimum 12 1914 3796' 371

sum

2 or 2 za iw JET PIERCING DEVICE BACKGROUND OF THE INVENTION This invention relates to hydraulic jet piercing devices particularly adapted for eroding holes or slots in hard and brittle materials such as rock, ore, coal, stratified earth formations and the like. In jet piercing devices a number of advantages can be gained from increasing the outlet diameter or area of flow of the nozzle in the generator producing the high velocity hydraulic jet. A first advantage is that the fraction of the total energy lost in friction to the walls of the eroded slot or hole decreases. This results in a higher stagnation pressure at any given depth below the surface worked upon and a consequent higher rate of material removal. A second advantage is a greater probability that the jet impacts upon a weakness line in the material worked upon such as a crystal boundary or flaw. A third advantage is that the erosion zone can be extended over more than one of the crystals making up the material worked upon. This means that the crystals of the material can be eroded by the liquid jet into a more or less intact unconfined state and are therefore easier to remove.

Nonnally these advantages, however, cannot be utilized in practice because of the disadvantage that nozzles enlarged to cut wider holes or slots require a prohibitive increase in the power input to the hydraulic jet generator if they are to operate on a sufficiently high pressure level.

It is therefore an object of this invention to create a novel hydraulic jet piercing device in which the above mentioned potential advantages of large diameter nozzles are made useful with a much lower consumption of power than would be required in the large diameter nozzle cases. Another object of the invention is to provide a hydraulic jet piercing device in which the area of flow of the jet nozzle outlet means has been distributed and orientated in a way enabling the jet emerging from the nozzle to erode a wide slot or hole without excessive consumption of power.

SUMMARY OF THE INVENTION For the above and other purposes there is according to the invention provided a hydraulic jet piercing device comprising a housing, a pressure chamber in said housing, means for supplying liquid to said chamber, a nozzle connected to said chamber, outlet means in said nozzle having a restricted area of flow relative to the area of flow of said chamber, a conically contracted passage in said nozzle extending between said chamber and outlet means, means associated with said housing for generating ultra high pressure in said chamber whereby a high velocity jet of liquid is expelled from said chamber via said passage through the restricted area of flow of said outlet means of said nozzle, means for feeding said housing in a direction transverse to said jet, and said area of flow of said nozzle being distributed and orientated transversely of the feeding direction of said housing.

BRIEF DESCRIPTION OF THE DRAWING The invention will be described in more detail in connection with the annexed drawings, wherein FIG. 1 is a longitudinal sectional view through a hydraulic jet piercing device embodying the invention. FIG. 2 is an enlarged sectional view on the line 22 in FIG. 1 and illustrates the nozzle portion of the jet piercing device shown therein. FIG. 3 is a fragmental front end view of the nozzle arrangement in FIG. 2. FIG. 4 is a longitudinal sectional view through a modified embodiment of the nozzle in FIG. 2. FIG. 5 is a front end view of the nozzle in FIG. 4. FIG. 6 is a front end view corresponding to FIG. 5 but of a third embodiment of the nozzle. FIG. 7 is a fragmentary section through a still further embodiment.

DETAIL DESCRIPTION OF PREFERRED EMBODIMENTS Referring to FIG. 1, the hydraulic jet piercing device depicted therein includes a housing 1 in which is provided a pressure chamber 2 in the shape of a cylindrical through bore. In the housing 1 is provided a nozzle 3 which is supported in coaxial relation with the working chamber 2 by a nozzle sleeve 4. The sleeve 4 is in threaded engagement with the housing 1. The pressure chamber 2 receives slidably therein the piston rod 5 of a differential piston 6 adapted to generate ultra high pressure in the chamber 2. The head of the piston 6 is slidably received in a cylinder 7 which is supported between front and rear end pieces 8, 9. The end pieces 8, 9 and the cylinder 7 are connected to the housing 1 by means of bolts 10. Hydraulic lines 11, 12 are in communication with the opposed ends of the cylinder 7 and are connected to a change-over valve 13 which is adapted to connect the lines 11, 12 alternatively to a supply 14 of hydraulic pressure and to a tank 15.

The chamber 2 is connected to a supply pump 16 arranged to supply liquid, preferably water, thereto through a conduit 17. The conduit 17 extends through the rear end piece 9 to a tube 18 carried thereby and slidably received in the piston 6. The tube 18 communicates with an internal passage 19 in the piston rod 5. The liquid supplied from the tube 18 to the passage 19 passes through a check valve 20 at the forward end of the piston rod 5 and keeps the pressure chamber 2 filled with liquid.

The housing 1 is guided on

guide bars

21, 22 forming part of a suitable machine frame, not shown. For the guiding, there are affixed two guide brackets 23 to the housing 1 by the bolts 10 and these brackets 22 are slidable on the bar 22. A sleeve 24 carried by the rear end piece 9 is slidable on the bar 21. The housing 1 may be moved laterally to and fro along the

guide bars

21, 22 by means of a feed chain 25 connected to a suitable feed motor, not shown, whereby the nozzle 3 is caused to pass along a rock or other surface 35 for piercing a series of holes or a slot 36 thereinto.

The nozzle 3 is made of hard and durable material such as tungsten carbide and is provided with an interior conically contracted passage 26. The passage 26 converges from the pressure chamber 2 towards the outlet means of the nozzle offering an area of flow for the liquid which is restricted relative to the area of flow of the working chamber 2 for enabling very high pressure to be generated in the pressure chamber 2. The total cone angle of the conically contracted passage is in the order of 12 15.

As depicted in FIGS. 2, 3 illustrating the first described embodiment, the outlet means of the nozzle 3 is distributed and orientated as to its area of flow in a longitudinal central plane of the nozzle 3 and is more particularly divided into two

outlets

27, 28 extending in substantially parallel spaced relation longitudinally of the nozzle. The width of the outlets is chosen of the order of 0.5 2 mm and is preferably about 1 mm for jet piercing devices of intermediate power and size. The outlet spacing may be of the order of 2 10 mm depending on the crystal structure of the material to be eroded, for example 3 mm in the case of granite.

In operation, pressure fluid is supplied from the supply 14 via the change-over valve 13 to cause the differential piston 6 to reciprocate in the cylinder 7 so as to operate as a pressure intensifier by its piston rod 5. The pump 16 delivers liquid via the conduit 17, the tube 18, the passage 19 in the piston rod 5, and the check valve 20 to the pressure chamber 2 for filling it up during the stroke of the piston rod away from the nozzle 3'. On each'stroke in the direction of the nozzle 3' the piston rod 5 produces very high pressure in the pressure chamber 2. The piston 6 has a large area which may be 8 24 times the cross sectional area of pressure chamber 2 and as a result the pressure of the pressure source 14 acting against the piston 6, which may be of the order of 0.25 0.35 kilobars, is intensified in the working chamber 2 to a pressure of the order of 3 kilobars. On each pressure intensifying stroke, the check valve 19 is closed thus interrupting the supply of liquid from the pump 16 to the chamber 2. By each pressure stroke, a high velocity jet of liquid is forcibly expelled from the pressure chamber 2 through the restricted area of flow of the nozzle 3 presented by the two

outlets

27, 28.

The reciprocating motion of the housing 1, which is provided by the chains 25, in FIG. 1, is performed in a feeding direction perpendicular to the plane of the

outlets

27, 28, as illustrated by arrow 30. This defines the maximum piercing width of the intermittent high velocity jet emerging from the nozzle 3. Depending on the crystalline character and the size of the crystal grains of the material cut, the depth of the produced slot 36 or row of holes can be varied by appropriate adjustment of the piercing width. The optimum cutting conditions may thus be found by adjusting the angular position of the plane of the

nozzle outlets

27, 28 relative to the feeding direction 30. To this end the nozzle sleeve 4 is loosened in the housing and a knob 31, affixed on the forward end of the nozzle 3 as by a pin 32, enables the nozzle 3 to be turned about the axis of the pressure chamber 2. Thereby the plane of the

outlets

27, 28 may be set relative to the feeding direction 30 so as to provide the optimum net piercing width between the

outlets

27, 28. The selected position is arrested by the sleeve 4 whereupon the pressure device is again started to operate.

In the embodiment depicted in FIGS. 4, 5 the nozzle 3 has a conical converging passage 26 as before but the outlet means thereof are provided by an undivided area of flow in the form of a single outlet 34 flattened relative to the nozzle 33 in a longitudinal central plane thereof. The length of the outlet 34 may be chosen 2 4 mm whereas the width may be 0.5 1.5 mm.

In the third embodiment illustrated in FIG. 6 the nozzle 36 again has a divided restricted area of flow defined by three

outlets

37, 38, 39 extending in spaced relation from the conically contracted passage, not shown but similar to previous passage 26 in FIG. 4, in the nozzle 36. The outlets 37 39 are terminated in orifices preferably of 1 mm size and disposed in triangular disposition with a spacing in the order of 3 10 mm.

In FIG. 7 the modified nozzle 41 is provided with a pair of

outlets

42, 43 converging in a point spaced forwardly of the tip of the nozzle 41.

The above described jet piercing device nozzles are equally suited for application in connection with per se known high pressure hydraulic jet generators of the type in which the jet is caused to emerge continuously rather than intermittently.

We claim:

1. A hydraulic jet piercing device comprising a housing, a pressure chamber in said housing, means for supplying liquid to said chamber, a nozzle connected to said chamber, outlet means in said nozzle having a restricted area of flow relative to the area of flow of said chamber, a conically contracted passage in said nozzle extending between said chamber and outlet means, means associated with said housing for generating ultra high pressure in said chamber whereby a high velocity jet of liquid is expelled from said chamber via said passage through the restricted area of flow of said outlet means of said nozzle, means for feeding said housing in a direction transverse to said jet, and said area of flow of said nozzle being distributed and orientated transversely of the feeding direction of said housing and means for hydraulically actuated differential piston means for amplifying the pressure to an ultra-high level in said chamber.

2. A jet piercing device according to claim 1 in which said conically contracted portion is coaxial with said nozzle.

3. A hydraulic jet piercing device comprising a housing, a pressure chamber in said housing, means for supplying liquid to said chamber, a nozzle connected to said chamber, outlet means in said nozzle having a restricted area of flow relative to the area of flow of said chamber, a conically contracted passage in said nozzle extending between said chamber and outlet means, means associated with said housing for generating ultra high pressure in said chamber whereby a high velocity jet of liquid is expelled from said chamber via said passage through the restricted area of flow of said outlet means of said nozzle, means for feeding said housing in a direction transverse to said jet, and said area of flow of said nozzle being distributed and orientated transversely of the feeding direction of said housing, said area of flow of said outlet means being defined by a single outlet flattened relative to said nozzle. 3

4. A hydraulic jet piercing device comprising a housing, a pressure chamber in said housing, means for supplying liquid to said chamber, a nozzle connected to said chamber, outlet means in said nozzle having a restricted area of flow relative to the area of flow of said chamber, a conically contracted passage in said nozzle extending between said chamber and outlet means, means associated with said housing for generating ultra high pressure in said chamber whereby a high velocity jet of liquid is expelled from said chamber via said passage through the restricted area of flow of said nozzle being distributed and orientated transversely of the feeding direction of said housing, said area of flow of said outlet means being defined by a pair of outlets extending in parallel spaced relation longitudinally of said nozzle.

5. A hydraulic jet piecing device comprising a housing, a pressure chamber in said housing, means for supplying liquid to said chamber, a nozzle connected to said chamber, outlet means in said nozzle having a restricted area of flow relative to the area of flow of said chamber, a conically contracted passage in said nozzle extending between said chamber and outlet means, means, associated with said housing for generating ultra high pressure in said chamber whereby a high velocity jet of liquid is expelled from said chamber via said passage through the restricted area of flow of said outlet means of said nozzle, means for feeding said housing in a direction transverse to said jet, and said area of flow of said nozzle being distributed and orientated transversely of the feeding direction of said housing means being provided in said housing for adjusting the angular orientation of said outlet means relative to in triangular orientation.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent N 3,796,371 Dated March 12, 1974 Inventor) Nicholas Simon Hall Taylor et a1 It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Claim 1, line 25 Cancel "means for" Signed and sealed this 23rd day of July 1971;.

(SEAL) Attest:

McCOY M. GIBSON, JR. 0. MARSHALL DANN Attesting Officer Commissioner of Patents USCOMM-DC 60376-P69 R U.S. GOVERNMENT PRINTING OFFICE: I969 0-866-334,

FORM PO-IOSO (10-69)

Claims

3. A hydraulic jet piercing device comprising a housing, a pressure chamber in said housing, means for supplying liquid to said chamber, a nozzle connected to said chamber, outlet means in said nozzle having a restricted area of flow relative to the area of flow of said chamber, a conically contracted passage in said nozzle extending between said chamber and outlet means, means associated with said housing for generating ultra high pressure in said chamber whereby a high velocity jet of liquid is expelled from said chamber via said passage through the restricted area of flow of said outlet means of said nozzle, means for feeding said housing in a direction transverse to said jet, and said area of flow of said nozzle being distributed and orientated transversely of the feeding direction of said housing, said area of flow of said outlet means being defined by a single outlet flattened relative to said nozzle.

5. A hydraulic jet piecing device comprising a housing, a pressure chamber in said housing, means for supplying liquid to said chamber, a nozzle connected to said chamber, outlet means in said nozzle having a restricted area of flow relative to the area of flow of said chamber, a conically contracted passage in said nozzle extending between said chamber and outlet means, means, associated with said housing for generating ultra high pressure in said chamber whereby a high velocity jet of liquid is expelled from said chamber via said passage through the restricted area of flow of said outlet means of said nozzle, means for feeding said housing in a direction transverse to said jet, and said area of flow of said nozzle being distributed and orientated transversely of the feeding direction of said housing means being provided in said housing for adjusting the angular orientation of said outlet means relative to said feeding direction thereby to adjust the piercing width of said jet.

6. A jet piercing device according to claim 5 in which said area of flow of said outlet means is defined by three outlets extending in spaced relation longitudinally of said nozzle and terminated in orifices disposed in triangular orientation.