Method and apparatus for removing collars from compressed gas cylinders
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a method and apparatus for removing collars from compressed gas cylinders and, more particularly, to a simple and rapid method and apparatus for removing collars from compressed gas cylinders which virtually eliminates the possibility of damaging the cylinder in any way. 
     2. Description of the Prior Art 
     In the field of compressed gas cylinders, it is common to place a cylinder collar on the top of the cylinder, the cylinder collar serving the function of identifying the owner of the cylinder whose name appears on the collar. While the collar will remain on the cylinder and not normally be removed therefrom, the need to remove the collar does in fact arise, primarily as necessitated by change in ownership of the cylinder. 
     Such a collar is generally put on a cylinder by being placed down over the neck of the cylinder, whereupon the metal on the top of the cylinder is swaged over the cylinder to lock it in place. Such technique for connecting the collar to the cylinder makes it difficult to subsequently remove the collar. Presently, collars are chiseled off, beat off with a hammer, severed with a cutting torch, pierced with hole saws, cut with abrasive discs, and pulled off hydraulically. 
     All of the preceding methods are slow and very time consuming and present the possibility of damaging the cylinder itself. Accordingly, there is a need for a simple technique for removing cylinder collars, one which can be done rapidly without the possibility of damaging the cylinder. Heretofore, such a technique has been unavailable. 
     SUMMARY OF THE INVENTION 
     According to the present invention, there is provided a simple and rapid technique for removing cylinder collars from compressed gas cylinders. The present technique is a two-step operation which can normally be done in approximately 30 seconds or less. Furthermore, the present technique virtually eliminates any possibility of damaging the cylinder itself. 
     Briefly, and in accordance with the present invention, there is provided a tool including a hydraulically driven ram and a fixed ram positioned in facing, spaced, coaxial relationship, the normal spacing between the fixed and driven rams being such as to permit the location of a cylinder collar therebetween. With a cylinder collar so positioned, the tool is activated to apply a lateral force to first opposite sides of the cylinder collar, at two points approximately 180° apart. The ends of the rams have sufficiently large surface areas to prevent penetration of the rams into the side walls of the collar. On the other hand, the force has a magnitude and the rams are of a shape such that the side walls of the collar are collapsed in the direction of the applied force and are elongated in a direction perpendicular to the direction of the applied force. The powered ram is then released and the tool is rotated 90° and actuated again. This applies a second lateral force to second opposite sides of the collar, at two points approximately 180° apart and approximately 90° from the first two points. The second step opens up the first sides of the collar, freeing the collar from the cylinder neck and allowing its easy removal. 
     OBJECTS 
     It is therefore an object of the present invention to provide a method for removing collars from compressed gas cylinders. 
     It is a further object of the present invention to provide apparatus for removing collars from compressed gas cylinders. 
     It is a still further object of the present invention to provide a method and apparatus for removing collars from compressed gas cylinders which permits a collar to be removed simply and rapidly. 
     It is another object of the present invention to provide a method and apparatus for removing collars from compressed gas cylinders which permits removal of the collar without damaging the cylinder in any way. 
     Still other objects, features, and attendant advantages of the present invention will become apparent to those skilled in the art from a reading of the following detailed description of the preferred embodiment constructed in accordance therewith, taken in conjunction with the accompanying drawings wherein like numerals designate like or corresponding parts in the several figures and wherein: 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of the present apparatus for removing collars from compressed gas cylinders, shown in operative relationship to a cylinder having a collar attached thereto, a portion of which collar is broken away; 
     FIG. 2 is a side elevation view of the apparatus of FIG. 1, shown in use in removing the collar from a compressed gas cylinder; and 
     FIG. 3 is a top plan view of the apparatus and cylinder shown in FIG. 2, showing the second collapsing step, with the first collapsing step being shown in phantom. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to the drawings, the present apparatus, generally designated 10, includes a hydraulically driven tool 11 of a type well-known to those skilled in the art. Tool 11 includes an elongate, generally cylindrical housing 12 having a cylindrical collar 13 at one end thereof and a ram 14 extending axially from such one end. The other end of housing 12 is connectable via a quick-disconnect coupling 15 to a hose 16 which is connectable to a source of hydraulic power. Suitable control means, not shown, causes the flow of hydraulic fluid via hose 16 and coupling 15 into housing 12, causing ram 14 to extend axially from housing 12. 
     Cylindrical collar 13 is machined to provide opposed flats 17 and 18 which receive a pair of flat rings 21 and 22, respectively. Rings 21 and 22 are positioned in parallel, spaced relationship and connected to flats 17 and 18, respectively, by welding or the like. 
     Tool 10 includes a fixed ram 25 having the same general dimensions a driven ram 14 and which is connected to a suitable support 26 which is connected between rings 21 and 22, such as by welding. Support 26 is connected to rings 21 and 22 so that ram 25 is positioned in facing, spaced, coaxial relationship to ram 14. The dimensions of tool 10 are such that rams 14 and 25 are normally spaced by an amount slightly greater than the usual outside diameter of the cylinder collar for a compressed gas cylinder. 
     FIG. 1 also shows an exterior view of the top of a compressed gas cylinder 30. Cylinder 30 has a neck 31 and a cylinder collar 32 placed therearound. After collar 32 is put over neck 31, the metal on the top of cylinder 30 is swaged, as shown at 33, to lock collar 32 in place. 
     OPERATION 
     Referring now primarily to FIGS. 2 and 3, apparatus 10 may be utilized to remove collar 32 from neck 31 of cylinder 30. The diameter of rings 21 and 22 is such that tool 10 may be placed down over collar 32, to the position shown in FIG. 2, with rams 14 and 25 facing collar 32 at two points approximately 180° apart. With tool 10 so positioned, the hydraulic power source is actuated, driving ram 14 towards ram 25. The ends of rams 14 and 25 have large enough surface areas to prevent penetration of rams 14 and 25 into collar 32. Furthermore, rams 14 and 25 are of a shape such that the applied force collapses the side walls of collar 32 in the direction of the applied force and simultaneously permits elongation of the side walls of collar 32 in a direction perpendicular to the direction of the applied force. Typically, ram 14 would generate approximately 20,000 PSI. The first step is shown in phantom in FIG. 3. 
     The source of hydraulic power is now removed and tool 10 is rotated through an angle of 90° so that rams 14 and 25 are now facing collar 32 at two points approximately 180° apart and approximately 90° from the first two points. The hydraulic power source is then reactuated, driving ram 14 towards ram 25 and collapsing the side walls of collar 32 in a direction perpendicular to the first direction. As shown in FIG. 3, the second force squeezes back in the previously elongated portion of the side walls of collar 32, opening; up the side walls of collar 30 which were pushed in during the first hydraulic actuation. The second step frees collar 32 from cylinder neck 31. 
     The hydraulic source of power is now removed from tool 10, releasing collar 32 from between rams 14 and 25 and allowing the easy removal of collar 32 from neck 31 of cylinder 30. The above operation can be done in approximately 30 seconds and as can be seen, is simple to achieve. Furthermore, there is virtually no possibility of damaging cylinder 30. 
     While the invention has been described with respect to the preferred embodiment constructed in accordance therewith, it will be apparent to those skilled in the art that various modifications and improvements may be made without departing from the scope and spirit of the invention. Accordingly, it is to be understood that the invention is not to be limited by the specific illustrative embodiment, but only by the scope of the appended claims.