Patent Document

BACKGROUND OF THE INVENTION  
         [0001]    The present invention relates to a torch, and in particular to a torch tip, designed for easy heating, brazing and soldering around tubular objects such as pipes, and particularly a plurality of pipes simultaneously.  
           [0002]    U.S. Pat. No. 4,191,333, the disclosure of which is incorporated herein by reference, discloses a hook-like flame tip including an arcuate body extending for a full half-circle with a short straight section with its distal end closed by a cap, and an angular rear terminal threaded for engagement with a conventional coupling connecting the flame tip to a conventional torch. The arcuate body includes a plurality of spaced radial flame apertures which direct flame jets to the object being heated, brazed or soldered, for example.  
           [0003]    Similarly, U.S. Pat. No. 5,755,568 discloses a multiflame torch tip including an elongated tubular handle or housing that mounts to a torch, a tubular stem, and a tip head joined to the tip stem, the tip head being arcuately curved through an angle of at least 240° and having two opposed closed terminal ends. The tip head includes a plurality of spaced outlet orifices which direct flame jets to the object being acted upon.  
           [0004]    Neither of these devices, however, is configured to attach or remove more than one pipe at a time. For instance, in a heat pump air conditioning system, a reversing or reciprocal valve can have a plurality of pipes, conduits or tubing connected thereto. Since the location of the reversing valve generally provides very little space in which to work, and since the plurality of pipes are spaced close together, it is virtually impossible to remove the pipes by liquefying the solder using conventional equipment. Indeed, often one or more of the pipes is removed by sawing, thereby requiring a time-consuming retrofit operation to reattach them.  
           [0005]    It is therefore an object of the present invention to provide a torch including a multiflame torch tip that can simultaneously remove or attach a plurality of pipes by heating, soldering, brazing or welding.  
           [0006]    It is a further object of the present invention to provide a torch tip that exhibits improved flame stability and flame direction accuracy.  
         SUMMARY OF THE INVENTION  
         [0007]    The problems of the prior art have been overcome by the present invention, which provides a torch including a torch tip adapted to be in fluid communication with a fuel gas and oxygen source for generating a flame, the torch tip including a tubular or substantially tubular body having a plurality of spaced orifices therein, wherein the tubular body preferably is substantially U-shaped and includes a pair of spaced substantially parallel elongated legs. The plurality of spaced orifices are located on each leg and are configured to each emit a flame towards an object to heat the same. The present invention also relates to a method of simultaneously attaching or removing a plurality of pipes or the like from an object using the torch tip.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]    [0008]FIG. 1 is a cross-sectional view of a torch tip in accordance with the present invention;  
         [0009]    [0009]FIG. 2 is an end view of the torch tip of FIG. 1;  
         [0010]    [0010]FIG. 3 is a perspective view of the torch tip in accordance with the present invention;  
         [0011]    [0011]FIG. 4 is a perspective view of the torch tip of the present invention shown in operation; and  
         [0012]    [0012]FIG. 5 is a cross-sectional view of another embodiment of the torch tip in accordance with the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0013]    Turning first to FIG. 1, torch tip  1  is shown having a substantially tubular shape in cross-section, including a longitudinal stem portion  10  having an inlet  12  adapted to be removably coupled to a torch by any suitable means, such as screw threads or a snap fit. Appropriate positioning of the tip stem portion  10  with respect to the torch member can be made prior to securing the tip stem on the torch member. The design of the torch member is not particularly limited, and can be conventional. In general, a torch member having an oxygen source passageway, a fuel gas (such as acetylene, MAPP or propane) passageway, and suitable valving for controlling the flow of oxygen and fuel gas is appropriate, such as that disclosed in U.S. Pat. No. 3,279,701, the disclosure of which is incorporated herein by reference. The tip stem  10  has an internal bore that is preferably uniform and circular in cross-section, to allow for smooth passage of the fuel gas and oxygen source mixture therethrough from the torch member to the tip head  15 , which also has an internal bore that is preferably uniform and circular in cross-section. The torch tip is preferably constructed out of stainless steel tubing, ¼ inch in outer diameter with 0.035 inch thick walls.  
         [0014]    Suitable fuel gases for use with the torch include acetylene, propane and MAPP. Suitable oxygen sources include pure oxygen and air.  
         [0015]    The end of the stem portion  10  opposite the inlet  12  is in fluid communication with tip head  15 , which is preferably U-shaped as shown. Those skilled in the art will appreciate that the stem portion  10  can be coupled to the tip head  15 , or the stem portion  10  and tip head  15  can be a single integral piece. For ease of construction, it is preferred that the stem portion  10  be coupled to the tip head  15  by welding. It is preferred that the stem portion  10  be centrally located with respect to the tip head  15  to help ensure even gas flow distribution throughout the tip head  15 .  
         [0016]    In a preferred embodiment, the tip head  15  includes a lower inlet portion  16 , which is preferably orthogonal relative to the stem  10 . A pair of substantially parallel elongated legs  18 ,  19  extend from the inlet portion  16  as shown, each terminating in a respective closed end  20 ,  21 . The ends  20 ,  21  can be closed by any suitable means, such as crimping or welding, with welding being preferred. The length of each leg  18 ,  19  is not particularly limited, and depends in part on the number and size of the tubing being worked upon. The length of each leg  18 ,  19  also determines the number and relative spacing of each flame orifice  25   a - 25   n.  In the embodiment shown, each leg is 4.75 inches long, measured from the point where the stem portion  10  meets the inlet portion  16  to the closed end  20  or  21 .  
         [0017]    A plurality of orifices  25   a - 25   n  are formed on each leg and are preferably equally spaced. In the embodiment shown, the orifices are spaced 1.125 inches apart, with orifice  25   a  spaced from the closed end  20  a distance of 0.156 inches. Each orifice  25   a - 25   n  in leg  18  is preferably positioned opposite a corresponding orifice in leg  19 . Each leg has four such orifices in the embodiment shown, although fewer or more could be used. As can be seen from FIGS. 1 and 2, the particular location of the orifices  25  is preferably offset at an angle from the bisecting plane of the tip head  15 . A suitable offset angle, measured from the center of the orifice  25  to the bisecting plane, is from about 30° to about 60°, most preferably about 40°. So offsetting the location of the orifices  25  directs the flame jets emanating therefrom away from the cutting or bisecting plane of the leg and away from the opposite leg (FIG. 3), thereby reducing the chance of overheating of the torch tip. Those skilled in the art will appreciate that the foregoing is provided by way of illustration, and the size of the torch tip, the number of orifices, and the spacing between them are not particularly limited.  
         [0018]    In one embodiment of the present invention (FIG. 5), the curvature of the tip head  15  is reduced or eliminated (relative to a circular cross-section) at least in the proximity of the desired location of each of the orifices in order to optimize the roundness of each orifice. For example, a flat or planar indentation is formed in the outer peripheral surface of the tip head  15 , such as by stamping, in each of the areas where the orifices are to be created. The size of each flat surface should be at least as large as the diameter of the respective orifice to be formed therein, and is preferably slightly larger. A suitable size for an orifice diameter of from about 22 to 32 mils is ⅛″ square. By way of further illustration, the distance from the center of the bore of the tip head  15  to the flat surface  12  (which flat surface can be considered a chord of the circle formed by the tip head  15 ) is 0.070″ for a tip head  15  having an outside diameter of {fraction (3/16)}″. The flat or planar surfaces allow for formation of a round or substantially round (in cross-section) orifice at an acute compound angle; drilling through a standard tube without such a planar surface results in the formation of an oval, rather than a round, orifice. Round orifices are preferred for flame stability. Where the fuel gas is acetylene, a suitable orifice diameter is 22±5 mils. Where the fuel gas is propane of MAPP, a suitable orifice diameter is 32±5 mils. Preferably each orifice is uniform in diameter throughout its length.  
         [0019]    In an alternative embodiment, the curvature of the tip head  15  is reduced or eliminated in the desired areas by removing a portion of the wall thickness of the tip head  15 , such as by cutting or machining.  
         [0020]    In yet a further embodiment, the configuration of the tubular tip head  15  can be chosen (or formed) such that a portion of its outer periphery spaced from the bisecting plane is planar throughout its entire arcuate length, giving the tip head  15  a cross-section along its entire arcuate length as shown in FIG. 5. The distance between each leg  20 ,  21 , defined by the length of the inlet portion  16  and the angles θ and θ′, which are preferably equal, depends upon the diameter of the tubing being worked upon, as the space between each leg must be sufficient to accommodate that tubing. In the embodiment shown, the space between legs  18  and  19  is 1.75 inches, although those skilled in the art will appreciate that smaller or larger spacing can be used depending upon the application.  
         [0021]    Turning now to FIG. 4, the torch of the present invention is shown in use to remove a plurality of pipes  30  from a reversing valve  35 . The torch head  16  is positioned with respect to the pipes  30  such that each of the pipes is heated simultaneously by the plurality of flame jets projecting from the orifices  25  of each leg  18 ,  19 . Upon liquefying of the solder holding the pipes to the reversing valve  35 , the pipes can be simultaneously removed. Similarly, a plurality of pipes can be simultaneously attached to the reversing valve.

Technology Category: 2