Abstract:
A method and apparatus for quenching a torch-cut work-piece wherein a spray curtain is mounted on a bearing with approximately 30° of the circular spray eliminated immediately behind the direction of travel. The spray direction is controlled by a friction operated directional spray arm carrying an idler wheel.

Description:
BACKGROUND AND SUMMARY OF INVENTION 
     This invention relates to a method and apparatus for quenching a torch-cut work-piece and, more particularly, to a novelly developed spray curtain for use in combination with a torch traveling with respect to the work-piece being cut. 
     For many years the art has utilized circular or conical shaped spray curtains in combination with cutting torches--see U.S. Pat. Nos. 2,227,476; 2,464,351; 3,815,833; 3,934,818; 4,168,055 and 4,358,091. In practice, this has resulted in a substantial amount of material to be scrapped or time spent in reclaiming cracks in formed material due to the water quench and tempering effect of the spray curtain. 
     According to the invention, the water curtain is controlled so that no spray is directed to the fine cut edge and hence the tempering problem has been solved--and the percentage of forming cracks has been reduced. More particularly, the invention involves moving a cutting torch relative to a work piece to be cut and directing an enveloping curtain of water about the torch for impingement upon the work-piece except against the portion of the work-piece just cut, viz., in preferred form, the trailing 30°. 
     Other objects and advantages of the invention may be seen in the details of construction and operation set down in the ensuing specification. 
    
    
     The invention is described in conjunction with the accompanying drawing, in which-- 
     FIG. 1 is a fragmentary perspective view of an embodiment of the invention in operation; 
     FIG. 2 is a sectional view taken along the sight line 2--2 of FIG. 1, viz., a vertical sectional view; and 
     FIG. 3 is a sectional view taken along the sight line 3--3 applied to FIG. 2, viz., a horizontal sectional view. 
    
    
     DETAILED DESCRIPTION 
     In the embodiment illustrated and with reference first to FIG. 1, the numeral 10 designates generally the inventive apparatus which is seen in the process of developing a cut 11 in a work-piece W and wherein the water curtain C partially envelopes the torch head 12. The interrupted trailing portion of the curtain 13 is advantageously of the order of 30° as can be appreciated from a consideration of FIG. 3 as well. The fact that the interrupted portion 13 trails the torch 12 can be appreciated also from noting the direction of travel as indicated by the arrow 14 (see both FIGS. 1 and 3). 
     The frame or structure responsible for developing the interrupted curtain can be best appreciated from FIG. 2 where the numeral 15 designates a collar which is clamped to the torch 12 by means of a clamping ring 16 equipped with a set screw 17. The collar 15 provides part of an annular race along with collar 18 for ball bearings 19. Thus, the outer collar 18 and the apparatus associated with it--to be described hereinafter--can swivel freely around the axis of the torch head 12. 
     Secured to the outer collar 18 in fixed relation therewith is a circular bracket 20 which has an upstanding shoulder 21. The upstanding, annular shoulder 21 is also equipped with a set screw as at 22 for fixedly securing the bracket 20 to the outer collar 18. Seals for the ball bearing race are provided above and below, the lower annular seal being designated 23 in FIG. 2. 
     The lower face of the bracket 20 is equipped with a depending flange as at 24 which is equipped with a plurality of threaded openings as at 25--for the receipt of cap screws 26 for securing a base plate 27 to the bracket 20. The base plate 27 is equipped with an upstanding flange as at 28 and defines with the depending flange 24 and annular chamber 29 for the distribution of water or other quenching fluid. 
     It will be appreciated that the base plate 27 can be readily removed and a different base plate substituted so as to develop a different water spray pattern. 
     For supplying water to the annular chamber 29, I provide a water inlet 30 in the bracket 20. Secured to this is a swivel conduit 31 which eliminates any entanglement of the water supply line 32 connected thereto. 
     It will be appreciated that the face plate 27 is equipped with a plurality of arcuately disposed water outlet ports as at 33--see particularly FIG. 3. These can assume any particular pattern as desired so long as the arcuate or perimetric extent is interrupted as at 13. In the illustration given, the interruption or lack of ports 33 is provided in an area flanking the inlet port 30. Thus, water entering the inlet port 30 is diverted left and right to supply the various ports 33. 
     Radially aligned with the blanked portion 13--radially in the sense of the axis of the cutting torch 12--is the idler wheel unit generally designated 34. The unit 34 includes a flanged block 35 which is bolted as at 36 (see FIG. 1) to the bracket 20. The block 35 is equipped with a vertical bore in which a wheel post 37 is slidably installed. The post 37, in turn, is equipped with set screw-fixed collars as at 38 and 39 which serve as stops for the spring 40. More particularly, the upper stop 38 limits the downward travel of the post 37--and hence the idler wheel 41--by coming into engagement with the upper surface of the block 35. 
     On the other hand, the stop 39 can be positioned to adjust the tension in the coiled spring 40 which allows the wheel 41 to roll over and foreign materials that could be lying on the surface of the plate and to roll easily off and on the edge of the plate or work-piece being cut. 
     As illustrated, the wheel 41 is carried in a bracket assembly 42 which is affixed to the lower end of the post 37. 
     Advantageous results have been attained through the use of an idler wheel made of brass which has a 7° pitch to center as at 43 (see FIG. 1)--thereby providing longer wear life. 
     OPERATION 
     In operation, the inventive apparatus can be adjusted to any cutting torch regardless of manufacture. The single row ball bearing unit including the inner and outer collars 15, 18 and balls 19 is clamped to the torch by means of a set screw 17 carried in the upper collar 16. 
     Also clamped to the ball bearing unit 15, 18 is a bracket 20 which in combination with the base plate 27 defines an annular chamber 29 for the distribution of quenching fluid introduced through the conduit 32. 
     The base plate 27 is apertured throughout a substantial protion of the arc around the torch 12 to provide the ports 33. The portion not apertured, viz., the angle 13, is aligned with the idler wheel unit 34 which is equipped with a spring 40 to permit the idler wheel 41 to ride over uneven surfaces. 
     With the inventive arrangement, the torch is movable through 360° but will allow no spray (or quenching) regardless of the shape being cut. 
     The weight of the torch and spray apparatus serves to compress the spring 40 somewhat and thereby sets the height of the spray pattern. By changing the position of the lower stop 39, this height can be adjusted further and protection against the spring 40 seeking to expell the post 37 and idler wheel unit from the block 35 is provided by the upper stop 38. Advantageously, the various parts of the apparatus clamped to the torch are constructed of brass and stainless steel to eliminate any corrosion or metal splatter build-up. 
     With the simple yet rugged mounting of the bottom face-plate 27, the plate port spacing and arrangment can be changed easily with the removal of the three screws 26 for different spray patterns. 
     Through the use of the inventive interrupted water spray curtain, one can control the spray area and eliminate any quenching of hot metal. This eliminates the creation of hardened areas that could crack during a forming process and thereafter be consigned to scrap. Also, from the operational standpoint, the operator does not have to shut off the water during some cuts which results in decreased productivity. 
     In the operation of the invention, it will be appreciated that the idler wheel assembly not only supports the torch head 12 but also constitutes a friction means for controlling the spray direction. As the torch head moves in different directions incident to a cut, the swivel mounting of the idler wheel assembly necessarily brings the curtain gap 13 into position immediately rearward of the cut, i.e., the spray is eliminated 180° from the direction of travel. 
     While in the foregoing specification a detailed description of an embodiment of the invention has been set down for the purpose of illustration, many variations in the details hereingiven may be made by those skilled in the art without departing from the spirit and scope of the invention.