Apparatus for generating a high-pressure fluid jet

Abstract

An improved apparatus for generating a high-pressure fluid jet includes an orifice mount having a frusto-conical surface that engages a frusto-conical wall in a cutting head, the geometry of the orifice mount and cutting head being selected to increase the stability of the mount and reduce deflection of the mount adjacent a jewel orifice, when subjected to pressure. Alignment of a nozzle body and the cutting head is improved by providing pilot diameters both upstream and downstream of threads on the nozzle body and bore of the cutting head, respectively. Accurate placement of a mixing tube in a cutting head is achieved by rigidly fixing a collar to an outer surface of the mixing tube, the collar engaging a shoulder and bore of the cutting head downstream of a mixing chamber, to precisely locate the mixing chamber axially and radially.

1 . An orifice mount for use in a high-pressure fluid jet system, comprising: 
 an orifice mount body having a frusto-conical outer surface, and wherein a radial distance from a longitudinal axis of the orifice mount body to a midpoint of the frusto-conical outer surface is 0.11-0.19 inch.    
     
     
         2 . The orifice mount according to  claim 1  wherein a longitudinal distance between the midpoint of the frusto-conical outer surface and a top surface of the orifice mount body is 0.15-0.3 inch.  
     
     
         3 . The orifice mount according to  claim 1  wherein the frusto-conical outer surface forms an included angle of 55-80°.  
     
     
         4 . The orifice mount according to  claim 1  wherein the orifice mount is formed of a material having a 2% yield strength of above 100,000 psi.  
     
     
         5 . The orifice mount according to  claim 1  wherein a lower region of the orifice mount body has an annular member extending parallel to the longitudinal axis of the body below the frusto-conical surface.  
     
     
         6 . The orifice mount according to  claim 1 , further comprising: 
 a jewel orifice positioned in an upper region of the orifice mount body.    
     
     
         7 . A cutting head for use in a high-pressure fluid jet system, comprising: 
 a body having a longitudinal bore extending therethrough along a longitudinal axis, a first region of the bore forming a frusto-conical wall in the body, and wherein a radial distance between the longitudinal axis of the cutting head and a midpoint of the frusto-conical wall is 0.11-0.19 inch.    
     
     
         8 . The cutting head according to  claim 7  wherein a second region of the bore is provided with a plurality of threads, and the bore defines a first pilot wall upstream of the threads and a second pilot wall downstream of the threads.  
     
     
         9 . The cutting head according to  claim 7  wherein the bore defines a mixing chamber downstream of the first region and the bore defines a shoulder in the cutting head body downstream of the mixing chamber.  
     
     
         10 . The cutting head according to  claim 7 , further comprising: 
 a vent hole extending laterally from the bore of the cutting head to an outer surface of the cutting head.    
     
     
         11 . A nozzle body for use in a high-pressure fluid jet system, comprising: 
 a nozzle body having a bore extending therethrough along a longitudinal axis, a first region of the nozzle body having a plurality of threads provided on an outer surface of the nozzle body, and a first pilot wall is provided upstream of the threads and a second pilot wall is provided downstream of the threads.    
     
     
         12 . A shield for use with a high-pressure fluid jet system, comprising: 
 an annular flange coupleable to an end region of a high-pressure fluid jet assembly, an annular skirt extending downward from the flange, and a disk of wear-resistant material positioned in an inner region of the shield.    
     
     
         13 . The shield according to  claim 12  wherein the disk is formed of polyurethane.  
     
     
         14 . A mixing tube for use in a high-pressure fluid jet system, comprising: 
 a mixing tube body having a bore extending therethrough along a longitudinal axis, and a collar rigidly fixed to an outer surface of the mixing tube in an upper region of the mixing tube, the collar being sized to slide upward through a bore of a cutting head and locate the mixing tube longitudinally in a desired location.    
     
     
         15 . The mixing tube according to  claim 14  wherein a distance from a top surface of the mixing tube body to a bottom surface of the collar is 0.02-2.0 inch.  
     
     
         16 . The mixing tube according to  claim 14  wherein a wall thickness of the collar is 0.01-0.2 inch.  
     
     
         17 . The mixing tube according to  claim 14  wherein an outer surface of the collar is substantially cylindrical.  
     
     
         18 . The mixing tube according to  claim 14  wherein an outer surface of the collar is substantially frusto-conical.  
     
     
         19 . The mixing tube according to  claim 14  wherein the collar is surrounded by a nut, an outer surface of the nut being threaded to engage a threaded inner surface of a cutting head.  
     
     
         20 . A mixing tube for use in a high-pressure fluid jet system, comprising: 
 a mixing tube body having a longitudinal bore extending therethrough defining an inlet to the mixing tube and an outlet, a first cylindrical region of the mixing tube body adjacent the inlet having a first outer diameter that is less than a second outer diameter of the mixing tube body downstream of the first cylindrical region.    
     
     
         21 . Apparatus for forming a high-pressure fluid jet, comprising: 
 a cutting head having a longitudinal bore extending therethrough along a longitudinal axis, a first region of the bore forming a frusto-conical wall in the cutting head; and    a nozzle body coupled to the cutting head, the nozzle body having a bore extending therethrough along a longitudinal axis, and wherein a ratio of the length of the frusto-conical wall of the cutting head to a diameter of the bore of the nozzle body is 0.2-0.47.    
     
     
         22 . The apparatus according to  claim 21  wherein a second region of the bore of the cutting head is provided with a plurality of threads, and the bore of the cutting head defines a first pilot wall upstream of the threads and a second pilot wall downstream of the threads, and wherein a lower region of the nozzle body is provided with a plurality of nozzle body threads, a third pilot wall upstream of the nozzle body threads and a fourth pilot wall downstream of the nozzle body threads, the first and second pilot walls of the cutting head engaging the third and fourth pilot walls of the nozzle body, respectively, when the nozzle body threads engage the threads in the bore of the cutting head.  
     
     
         23 . The apparatus according to  claim 21 , further comprising: 
 a mixing tube having a collar rigidly fixed to an outer surface of the mixing tube in an upper region of the mixing tube, the collar being sized to slide upward through the bore of the cutting head and locate the mixing tube longitudinally in a desired location.    
     
     
         24 . The apparatus according to  claim 23 , further comprising: 
 a collet surrounding the mixing tube below the collar and received in the bore of the cutting head, the collet being tightened against the mixing tube by a nut that is selectively tightened and loosened, the collar engaging a top surface of the collet to retain the mixing tube in the cutting head when the nut is loosened.    
     
     
         25 . The apparatus according to  claim 24 , further comprising: 
 a shield having an annular flange coupled to an end region of the high-pressure fluid jet assembly, a disc of wear-resistant material being positioned in an inner region of the shield adjacent the mixing tube.    
     
     
         26 . The apparatus according to  claim 21  wherein the cutting head is provided with a vent hole extending laterally from an outer surface of the cutting head to the bore of the cutting head.  
     
     
         27 . Apparatus for forming a high-pressure fluid jet, comprising: 
 a cutting head having a longitudinal bore extending therethrough along a longitudinal axis, a first region of the bore forming a frusto-conical wall in the cutting head;    an orifice mount having a frusto-conical outer surface that is positioned adjacent the frusto-conical wall of the cutting head when the orifice mount is positioned in the bore of the cutting head, the orifice mount having an annular member extending parallel to the longitudinal axis of the bore below the frusto-conical surface of the orifice mount; and    wherein the cutting head is provided with a vent hole extending laterally from an outer surface of the cutting head to a point adjacent the annular member of the orifice mount.    
     
     
         28 . Apparatus for forming a high-pressure fluid jet, comprising: 
 a cutting head having a longitudinal bore extending therethrough along a longitudinal axis, a first region of the bore forming a mixing chamber, and a shoulder is provided in the cutting head downstream of the mixing chamber; and    a mixing tube having a collar rigidly fixed to an outer surface of the mixing tube, the collar seating against the shoulder in the cutting head body to longitudinally locate the mixing tube in the cutting head body.    
     
     
         29 . The apparatus according to  claim 28 , further comprising: 
 an o-ring positioned between the collar of the mixing tube and the shoulder of the cutting head body.    
     
     
         30 . The apparatus according to  claim 28  wherein the collar has a conical outer surface that matingly engages a conical region of the bore of the cutting head, thereby radially positioning the mixing tube in the cutting head body.  
     
     
         31 . The apparatus according to  claim 28 , further comprising: 
 a collet surrounding the mixing tube below the collar and received in the bore of the cutting head, the collet being tightened against the mixing tube by a nut that is selectively tightened and loosened, the collar engaging a top surface of the collet to retain the mixing tube in the cutting head when the nut is loosened.    
     
     
         32 . Apparatus for forming a high-pressure fluid jet, comprising: 
 a cutting head having a longitudinal bore extending therethrough along a longitudinal axis, a first region of the bore being provided with a plurality of threads, and wherein the bore of the cutting head defines a first pilot wall upstream of the threads and a second pilot wall downstream of the threads; and    a nozzle body coupled to the cutting head, an outer surface of the nozzle body being provided with a plurality of nozzle body threads, and with a third pilot wall upstream of the nozzle body threads and a fourth pilot wall downstream of the nozzle body threads, the first and second pilot walls of the cutting head engaging the third and fourth pilot walls of the nozzle body, respectively, when the nozzle body threads engage the threads in the bore of the cutting head.    
     
     
         33 . Apparatus for forming a high-pressure fluid jet, comprising: 
 an orifice mount having a frusto-conical outer surface; and    a nozzle body coupled to the orifice mount, the nozzle body having a bore extending therethrough along a longitudinal axis, and wherein a ratio of a length of the frusto-conical outer surface of the orifice mount to a diameter of the bore of the nozzle body is 0.2-0.47.