Abstract:
A method of directing a gas flow in a tip of a gas torch includes: directing a flow of gas to an outer passageway of the tip; directing the flow of gas inwardly through at least one intermediate gas passageway; directing the flow of gas to a central gas passageway of the tip; and directing the flow of gas distally through a distal orifice of the tip.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a divisional of and claims the benefit of U.S. application Ser. No. 12/849,028, filed on Aug. 3, 2010 and titled “GAS CUTTING TIP WITH IMPROVED FLOW PASSAGE,” which is now issued U.S. Pat. No. 8,609,020, issued Dec. 17, 2013, the content of which is incorporated herein by reference in its entirety. 
    
    
     FIELD 
     The present disclosure relates generally to a gas cutting torch and more particularly to a tip of a gas cutting torch having improved flow passage for enhanced cooling. 
     BACKGROUND 
     The statements in this section merely provide background information related to the present disclosure and may not constitute prior art. 
     Oxy-fuel cutting torches, or gas cutting torches, generally employ oxygen and a fuel gas, such as acetylene or propane, by way of example, to cut a workpiece. More specifically, preheat oxygen and the fuel gas are mixed and ignited to provide heat to the workpiece, and then additional oxygen, commonly referred to as cutting oxygen, is added to react with the heated workpiece. This reaction of the cutting oxygen with the heated workpiece initiates sufficient heat and momentum of the gases to initiate a cutting process. 
     A typical gas cutting torch generally includes a consumable gas cutting tip which conducts cutting oxygen straight through a central passageway within the tip and includes a plurality of axial passageways for the flow of preheat gas (i.e., mixed preheat oxygen and fuel gas). Gas cutting tips with this traditional flow passage are easy to manufacture, but they are not optimal for cooling of the tip. Gas cutting tips having improved flow passage for enhanced cooling effect are desired in the field of gas cutting torches. 
     SUMMARY 
     In one form, the present disclosure generally provides a method of directing a gas flow in a tip of a gas torch. The method includes: directing a flow of gas to an outer passageway of the tip; directing the flow of gas inwardly through at least one intermediate gas passageway; directing the flow of gas to a central gas passageway of the tip; and directing the flow of gas distally through a distal orifice of the tip. 
     In another form of the present disclosure, a method of directing a gas flow in a tip of a gas torch is provided, wherein the tip includes an inner tip and an outer tip. The method includes: directing a flow of gas distally along an outer surface of the inner tip; directing the flow of gas inwardly from the outer surface of the inner tip into a central gas passageway in the inner tip; and directing the flow of gas distally along the central gas passageway. 
     In still another form, the present disclosure provides a method of directing a gas flow in a tip of a gas torch. The method includes: directing a flow of gas distally along an outer passageway that is offset from a central gas passageway of the tip; and directing the flow of gas inwardly from the outer passageway to the central gas passageway of the tip. 
     Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. 
    
    
     
       DRAWINGS 
       The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way. 
         FIG. 1   a  is a partial cross-sectional view of a typical tip of a gas torch known in the art; 
         FIG. 1   b  is a perspective view of the tip of  FIG. 1   a;    
         FIG. 2  is a perspective view of a gas cutting torch constructed in accordance with the principles of the present disclosure; 
         FIG. 3   a  is a partial cross-sectional view of one form of a tip for use in a gas torch constructed in accordance with the principles of the present disclosure; 
         FIG. 3   b  is an alternate partial cross-sectional view of the tip of  FIG. 3   a;    
         FIG. 4  is cross-sectional view of another form of a tip for use in a gas torch, taken along a line through the intermediate passageways of the inner tip portion of the tip; 
         FIG. 5   a  is a partial cross-sectional view of another form of a tip for use in a gas torch constructed in accordance with further principles of the present disclosure; 
         FIG. 5   b  is a perspective view of the tip of  FIG. 5   a;    
         FIG. 6  is a perspective view of a tip assembly for use in a gas torch constructed in accordance with the principles of the present disclosure; 
         FIG. 7  is an exploded view of the tip assembly of  FIG. 6 ; 
         FIG. 8   a  is a partial cross-sectional view of the tip assembly of  FIG. 6  taken along line  8   a - 8   a ; and 
         FIG. 8   b  is a partial cross-sectional view of the tip assembly of  FIG. 6  taken along line  8   b - 8   b.    
     
    
    
     DETAILED DESCRIPTION 
     The following description is merely exemplary in nature and is in no way intended to limit the present disclosure, its application, or uses. It should be understood that throughout the description and drawings, corresponding reference numerals indicate like or corresponding parts and features. 
     Referring to  FIGS. 1   a - b , a typical tip for use with a gas cutting torch is illustrated and generally indicated by reference numeral  10 . The tip  10  comprises a body  12  having a proximal end portion  14  which attaches to a torch head of the gas cutting torch (not shown) and a distal end portion  15  through which the gas exits to perform the cutting operation. The body  12  defines a central gas passageway  16  for the flow of cutting oxygen and a plurality of axial passageways  18  for the flow of preheat gas, e.g., premixed oxygen and fuel gas. Thus, cutting oxygen flows from a passage within the torch head of the gas cutting torch straight through the center, or central passageway  16 , of the tip  10 . Tips  10  having the traditional straight-through design are easy to manufacture, however, they are not designed for optimal cooling of the tip  10 . 
     Various forms of the present disclosure comprise an improved tip for use with a gas cutting torch designed for enhanced cooling in comparison to traditional tips such as those illustrated and described with respect to  FIGS. 1   a - b . Referring to  FIG. 2 , a gas cutting torch in accordance with the teachings of the present disclosure is illustrated and generally indicated by reference numeral  20 . The gas cutting torch  20  includes a torch head  21  and a tip  22  secured to the torch head  21 , the tip  22  having an improved flow passage designed for enhanced cooling, various forms of which are described in further detail below and indicated by corresponding reference numerals increased by increments of 100. 
       FIGS. 3   a - b  illustrate one form of a tip  122  in accordance with the teachings of the present disclosure. The tip  122  includes a proximal end portion  114  which attaches to the torch head  21  of the gas cutting torch  20  and a distal end portion  115  through which the gas exits to perform the cutting operation. In this form, the tip  122  comprises an outer tip portion  124  having a proximal portion  126  and a distal portion  128 . The outer tip portion  124  defines an outer surface  130  and an inner surface  132  and further defines a central cavity  134  and a distal orifice  136 . An inner tip portion  140  is disposed within the central cavity  134  of the outer tip portion  124 . In one form, the outer tip portion  124  and the inner tip portion  140  are separate components. In another form, the outer tip portion  124  and the inner tip portion  140  are unitarily formed as a single piece by any suitable means in the art, such as, e.g., lost-wax casting. 
     The inner tip portion  140  has a proximal portion  142  and a distal portion  144  and defines an outer surface  146  and an inner surface  148 . The inner tip portion  140  further defines a central gas passageway  150  having a proximal end portion  152  generally occluded by a component of the gas cutting torch  20  extending to a distal end portion  154  in fluid communication with the distal orifice  136  of the outer tip portion  124 . Additionally, the inner tip portion  140  defines at least one intermediate gas passageway  156  extending from the outer surface  146  of the inner tip portion  140  to the central gas passageway  150  for the flow of at least one gas to provide improved cooling to the tip  122 , as described in further detail below. More specifically, in one form of the present disclosure, a plurality of intermediate gas passageways  156  extends between the outer surface  146  of the inner tip portion  140  and the central gas passageway  150 . 
     As shown in  FIGS. 3   a - b , the tip  122  defines a proximal annular gas passageway  160  and a distal annular gas passageway  162 . The proximal annular gas passageway  160  is disposed between the inner surface  132  of the proximal portion  126  of the outer tip portion  124  and the outer surface  146  of the proximal portion  142  of the inner tip portion  140 . The distal annular gas passageway  162  is disposed between the inner surface  132  of the distal portion  128  of the outer tip portion  124  and the outer surface  146  of the distal portion  144  of the inner tip portion  140 . In this form, the proximal and distal annular gas passageways  160 ,  162  are generally not in fluid communication with one another due to the size and configuration of the inner tip portion  140  within the central cavity  134  of the outer tip portion  124 . As further illustrated in  FIG. 3   b , the inner tip portion  140  defines at least one offset axial passageway  166  that extends from within the proximal portion  142  of the inner tip portion  140  to the distal annular gas passageway  162 . 
     The tip  122  is attached to the torch head  21  of the gas cutting torch  20  by any suitable means known or contemplated in the art. For example, the torch head  21  may have external threads for receiving a threaded tip nut for connecting the tip  122  to the torch head  21 . Alternatively, in another form of the present disclosure, a tip seat may be secured to the torch head  21  and the tip  122  secured to the tip seat by way of a locking nut. The gas cutting torch  20  generally includes a plurality of internal gas supply tubes for the flow of preheat oxygen, fuel gas, and cutting oxygen and the torch head  21  generally includes a plurality of passages in fluid communication with the gas supply tubes and through which the preheat oxygen, fuel gas, and cutting oxygen flow and enter the tip  122 . 
     In operation, preheat gas, e.g., mixed preheat oxygen and fuel gas (i.e., acetylene, propane, liquid petroleum, or natural gas) flows from a passage within the torch head  21  (or from a mixer, as discussed in further detail with respect to  FIGS. 6-8 ) into the axial passageway  166  within the inner tip portion  140  of the tip  422 . The preheat gas flows through the axial passageway  166  into the distal annular gas passageway  162  and exits the distal portion  115  of the tip  122 . In this form, the proximal portion  152  of the central gas passageway  150  is occluded by a component of the gas cutting torch  20  (e.g., a mixer, as discussed in further detail with respect to  FIGS. 6-8 ). 
     Accordingly, cutting oxygen does not flow from the torch head  21  straight through the central passageway  150  of the tip  122  as in the traditional tip  10  of  FIGS. 1   a - b . Rather, cutting oxygen flows from a passage within the torch head  21  into the proximal annular gas passageway  160  and from the proximal annular gas passageway  160  into the central gas passageway  150  via the intermediate gas passageways  156 . The cutting oxygen thus flows in between the inner and outer tip portions  140 ,  124  before entering the central gas passageway  150  via the intermediate passageways  156 . The geometry of the cutting oxygen flow passage, i.e., the extra surface area of the inner and outer tip portions  140 ,  124  in contact with the cutting oxygen, results in an enhanced cooling effect. The enhanced cooling not only prolongs the lifetime of the consumable tip  122 , but allows for a smaller tip  122 , resulting in a more compact design due to the reduced distance between the distal orifice  136  and the point of entry of the cutting oxygen (i.e., the proximal end portion  114  of the tip  422 ). 
     In  FIG. 3   a , the intermediate passageways  156  extend radially between the outer surface  146  of the inner tip portion  140  and the central gas passageway  150 . Alternatively, the intermediate passageways  156  may extend at an angle between the outer surface  146  of the inner tip portion  140  and the central gas passageway  150 . In another form of the present disclosure, as illustrated in  FIG. 4 , the intermediate passageways  256  define a swirl configuration between the outer surface  246  of the inner tip portion  240  and the central gas passageway  250 . 
     In one form, the inner tip portion  140  includes at least one raised ridge or rib  170  extending along at least a portion of the outer surface  146  of the inner tip portion  140  and at least one flute disposed adjacent the rib  170 .  FIG. 7  best illustrates an inner tip portion  440  of a tip  422  having a plurality of ribs  470  and flutes  468  extending along the outer surface  446  thereof to provide cooling as the gas passes through the flutes  468 . Alternatively, or in combination, the tip  122  may include at least one rib and at least one flute extending along at least a portion of the inner surface  132  of the outer tip portion  124 . Additionally, the tip  122  may include a dielectric spacer disposed between the outer tip portion  124  and the inner tip portion  140 . The dielectric spacer may include at least one rib and at least one flute extending along at least a portion of the inner surface of the dielectric spacer proximate the inner tip portion. 
     Further, the inner tip portion  140  is conductive and is adapted for electrical connection to an ignition system of the gas torch  20 . An ignition wire (not shown) from an ignition system extends through the tip  122  and is in electrical contact with the conductive inner tip portion  140  and thus generates the spark for ignition of the gas cutting torch  20 . 
     Referring to  FIGS. 5   a - b , another form of a tip for use with a gas cutting torch  20  in accordance with further teachings of the present disclosure is illustrated and generally indicated by reference numeral  322 . The tip  322  generally comprises a body  312  having a proximal end portion  314  which attaches to the torch head  21  and a distal end portion  315  through which the gas exits to perform the cutting operation. In this form, the body  312  defines at least one axial passageway  366  extending from the proximal end portion  314  to the distal end portion  315  for the flow of preheat gas and a central gas passageway  350  for the flow of cutting oxygen. Additionally, the body  312  defines at least one intermediate gas passageway  356  extending at an angle between the outer surface of the body  312  and the central gas passageway  350  for the flow of at least one gas to provide improved cooling to the tip  322 . As shown in  FIG. 5   a , the central gas passageway  350  is occluded near the proximal end portion  314  of the tip  322 . 
     In operation, the axial passageway  366  receives preheat gas from a passage in the torch head  21 . The central gas passageway  350  receives cutting oxygen via the intermediate gas passageways  356  in fluid communication with a cutting oxygen passage within the torch head  21 . Similar to the tip  122  of  FIGS. 3   a - b , the geometry of the cutting oxygen flow passage of the tip  322  provides enhanced cooling as a result of the extra surface area (i.e., the intermediate gas passageways  356 ) in contact with the cutting oxygen. 
     Referring now to  FIGS. 6 ,  7 , and  8   a - b , a tip assembly for use with a gas cutting torch in accordance with further teachings of the present disclosure is illustrated and generally indicated by reference numeral  408 . The tip assembly  408  comprises a tip  422  having a proximal end portion  414  which attaches to a torch head  421  and a distal end portion  415  through which gas exits to perform the cutting operation. The tip assembly  408  further comprises a mixer  480  attached to the proximal end portion  414  of the tip  422  and the torch head  421 . 
     The tip  422  includes an outer tip portion  424  having a proximal portion  426  and a distal portion  428 . The outer tip portion  424  defines an outer surface  430  and an inner surface  432  and further defines a central cavity  434  and a distal orifice  436 . An inner tip portion  440  is disposed within the central cavity  434  of the outer tip portion  424 . In  FIG. 7 , the outer tip portion  424  and the inner tip portion  440  are separate components. However, the outer tip portion  424  and the inner tip portion  440  may be unitarily formed as a single piece by any suitable means in the art, such as, e.g., lost-wax casting. 
     The inner tip portion  440  has a proximal portion  442  and a distal portion  444  and defines an outer surface  446  and an inner surface  448 . The inner tip portion  440  defines a central gas passageway  450  having a proximal portion  452  generally occluded by a component of the gas cutting torch, i.e., the mixer  480 , as described in further detail below. The central gas passageway  450  extends from the proximal portion  452  to a distal portion  454  in fluid communication with the distal orifice  436  of the outer tip portion  424 . Additionally, the inner tip portion  440  defines at least one intermediate gas passageway  456  extending from the outer surface  446  of the inner tip portion  440  to the central gas passageway  450  for the flow of at least one gas to provide improved cooling to the tip  422 , as described in further detail below. 
     As best illustrated in  FIGS. 8   a - b , the tip  422  includes a proximal annular gas passageway  460  and a distal annular gas passageway  462 . The proximal annular gas passageway  460  is disposed between the inner surface  432  of the proximal portion  426  of the outer tip portion  424  and the outer surface  446  of the proximal portion  442  of the inner tip portion  440 . The distal annular gas passageway  462  is disposed between the inner surface  432  of the distal portion  428  of the outer tip portion  424  and the outer surface  446  of the distal portion  444  of the inner tip portion  440 . As further illustrated in  FIG. 8   b , the inner tip portion  440  defines at least one offset axial passageway  466  that extends from within the proximal portion  442  of the inner tip portion  440  to the distal annular gas passageway  462 . 
     The tip assembly  408  further includes a mixer  480  for mixing preheat oxygen and fuel gas to form a preheat gas mixture. A mixer  480  in accordance with the teachings of the present disclosure is also disclosed in U.S. patent application Ser. No. 12/849,030 entitled “Improved Mixer for a Gas Cutting Torch” to MacKenzie et al., the entire contents of which are incorporated by reference herein. As illustrated in  FIGS. 8   a - b , the mixer  480  includes a proximal end portion  482  adapted for removable connection to the torch head  421  and a distal end portion  484  adapted for connection to the tip  422 . In this form, the distal end portion  484  of the mixer  480  matingly fits within a proximal recess  438  of the inner tip portion  440 . The distal end portion  484  of the mixer  480  thus occludes the proximal portion  452  of the central gas passageway  450  of the inner tip portion  440 . The proximal portion  482  of the mixer  480  defines a connecting member  486  for removably connecting the mixer  480  to the torch head  421 . As best illustrated in  FIGS. 8   a - b , the connecting member  486  includes a detent that engages a recess formed within the torch head  421 . The connecting member  486  may alternatively include threads or any other suitable connection means known or contemplated in the art for removably connecting the mixer  480  to the torch head  421 . 
     The mixer  480  defines an outer surface  488  and an inner surface  490  and a plurality of internal gas passageways, including a central gas passageway  492 , a plurality of proximal gas passageways  494 , and a plurality of distal gas passageways  496 . In this form, the central gas passageway  492  extends from a proximal end  491  at the proximal end portion  482  of the mixer  480  to a distal end  493  proximate the distal end portion  484  of the mixer. The plurality of proximal gas passageways  494  extend from the outer surface  488  of the proximal end portion  482  of the mixer  480  to the central gas passageway  492 . In  FIGS. 8   a - b , the proximal gas passageways  494  extend radially between the outer surface  488  of the mixer  480  and the central gas passageway  492 . In another form, the proximal gas passageways  494  may extend at an angle between the outer surface  488  of the mixer  480  and the central gas passageway  492  or in a spiral configuration similar to the intermediate passageways of the tip of  FIGS. 5   a - b  and  4 , respectively. 
     The plurality of distal gas passageways  496  extend from the distal end  493  of the central gas passageway  492  to the outer surface  488  of the distal end portion  484  of the mixer  480 . In this form, the distal gas passageways  496  extend at an angle between the central gas passageway  492  and the outer surface  488  of the distal end portion  484  of the mixer  480 . 
     As illustrated in  FIGS. 6-8 , the tip assembly  408  further comprises a locking ring  498  for connecting the tip  422  and the mixer  480  to the torch head  421  and a spacer  499  disposed between the locking ring  498  and the outer surface  430  of the proximal portion  426  of the outer tip portion  424 . 
     The torch head  421  generally includes a plurality of passages in fluid communication with gas supply tubes within the gas cutting torch  20 . As illustrated in  FIGS. 8   a - b , the torch head  421  includes a cutting oxygen inlet bore  472 , a preheat oxygen inlet bore  474 , and a fuel gas inlet bore  476  for receiving cutting oxygen, preheat oxygen, and fuel gas from respective supply tubes within the gas cutting torch  20 . The torch head  421  defines at least one cutting oxygen passage  473  extending from the cutting oxygen inlet bore  472 , a preheat oxygen passage  475  extending from the preheat oxygen inlet bore  474 , and a fuel gas passage  477  extending from the fuel gas inlet bore  476 . It is noted that the positioning of the preheat oxygen inlet bore  474  and corresponding preheat oxygen passage  475  and the fuel gas inlet bore  476  and corresponding fuel gas passage  477  may be switched, i.e., reference numerals  474 ,  475  and  476 ,  477  may designate either the preheat oxygen inlet bore and passage or the fuel gas inlet bore and passage. 
     The tip  422  and the mixer  480  are connected to the torch head  421  such that the cutting oxygen passage  473  and the proximal annular passageway  460  of the tip  422  are in fluid communication; and such that one of the preheat oxygen passage  475  and the fuel gas passage  477  is in fluid communication with the central passageway  492  of the mixer  480  and the other one of the preheat oxygen passage  475  and the fuel gas passage  477  is in fluid communication with the proximal gas passageways  494  of the mixer. In  FIG. 8   a , the preheat oxygen passage  475  and the central gas passageway  492  of the mixer  480  are in fluid communication via the recess  423  formed within the torch head  421 , and the fuel gas passage  477  and the proximal gas passageways  494  of the mixer  480  are in fluid communication. 
     In operation, preheat oxygen and fuel gas (i.e., acetylene, propane, liquid petroleum, or natural gas) are mixed within the mixer  480  to form preheat gas. More specifically, preheat oxygen flows from an internal preheat oxygen supply tube within the gas torch  20  into the preheat oxygen passage  475  via the preheat oxygen inlet bore  474 . The preheat oxygen flows through the preheat oxygen passage  475  and the recess  423  formed within the torch head  421  and enters the proximal end  491  of the central gas passageway  492  of the mixer  480 . The fuel gas flows from an internal fuel gas supply tube within the gas torch  20  into the fuel gas passage  477  via the fuel gas inlet bore  476 . The fuel gas flows through the fuel gas passage  477  within the torch head  421  and enters the central gas passageway  492  of the mixer  480  via the plurality of proximal gas passageways  494 . The preheat oxygen and the fuel gas mix within the mixer  480  as they flow together through the central gas passageway  492 . The mixed preheat gas then flows from the mixer  480  to the at least one axial gas passageway  466  via the angled distal gas passageways  496 . The preheat gas flows through the axial passageway  466  into the distal annular gas passageway  462  and exits the distal portion  415  of the tip  422 . 
     Additionally, cutting oxygen flows from an internal cutting oxygen supply tube within the gas torch  20  into the cutting oxygen passage  473  via the cutting oxygen inlet bore  472 . As illustrated in  FIGS. 8   a - b , the proximal portion  452  of the central gas passageway  450  of the inner tip portion  440  of the tip  422  is occluded by the distal end portion  484  of the mixer  480 . Accordingly, cutting oxygen does not flow from the torch head  421  straight through the central gas passageway  450  of the tip  422  as in the traditional tip  10  of  FIGS. 1   a - b . Rather, cutting oxygen flows from the cutting oxygen passage  473  within the torch head  421  into the proximal annular gas passageway  460  of the tip  422  and from the proximal annular gas passageway  460  into the central gas passageway  450  via the intermediate gas passageways  456 . The cutting oxygen thus flows in between the inner and outer tip portions  440 ,  424  before entering the central gas passageway  450  via the intermediate passageways  456 . 
     Accordingly,  FIGS. 6 ,  7 , and  8   a - b  illustrate a tip assembly  408  including a consumable tip  422  having an improved flow passage geometry for enhanced cooling of the tip  422  due to the extra surface area of the inner and outer tip portions  440 ,  424  in contact with the cutting oxygen. The enhanced cooling not only prolongs the lifetime of the consumable tip  422 , but allows for a smaller tip  422 , resulting in a more compact design due to the reduced distance between the distal orifice  436  and the point of entry of the cutting oxygen (i.e., the proximal end portion  414  of the tip  422 ). More specifically, a tip having a traditional flow passage similar to that shown in  FIGS. 1   a - b  typically has a length of about 2.5 inches whereas a tip  422  having an improved flow passage in accordance with the teachings of the present disclosure, in one example, has a length of about 1.5 inches. Additionally, the mixer  480  of the tip assembly  408  defines a distended length and allows for a tip  422  having a reduced length. With a reduction in tip size follows a reduction in material, e.g., copper, and thus a reduction in cost. 
     The present disclosure is merely exemplary in nature and, thus, variations that do not depart from the gist of the disclosure are intended to be within the scope of the present disclosure. Such variations are not to be regarded as a departure from the spirit and scope of the present disclosure.