Pipe cutting tool

Abstract

A pipe cutting tool particularly adapted for cutting off PVC waste pipe or the like below floor level, such as below the level of concrete in which the pipe is encased. The tool includes a depth gauge drum and cutter head mounted on a shaft adapted to be driven by an electric hand drill. The cutter head or drum carries a bit which is urged into the work by springs and which includes a leading guide leg or finger for controlling the depth of the cut and a trailing cutting leg spaced from the guide leg to permit clearance of cuttings.

What is claimed as new and what it is desired to secure by Letters Patent of the United States is: 
     
       1. An inside cutter for cutting off at a desired level below the concrete surface, plastic pipe of predetermined diameter encased in concrete, such pipe having an end exposed outwardly of the concrete surface, comprising, a shaft having an end portion adapted for connection to shaft rotating means, a cutting head drum and a guide drum mounted on said shaft, first means for mounting said guide drum on said shaft, second means for fixing said cutting head drum on said shaft for rotation therewith, one of said first and second means being selectively releaseable to permit adjustment of the distance between said drums, said guide drum comprising a cylindrical portion disposed toward said cutting head drum and an outwardly extending flange portion disposed away from said cutting head drum and adapted to engage the end surface of the exposed end of the pipe, said cutting head drum comprising a cylindrical body portion and a cutting bit movably supported thereon and projectable laterally thereof, said bit comprising a leading leg and a trailing cutting leg terminating outwardly in an outward cutting edge disposed outwardly a short distance beyond the outer end of said leading leg as measured radially from the axis of said cutting head drum, said cylindrical portion of said cutting head drum being proportioned to fit closely within and to be freely rotatable within the pipe, and spring means engaged between said body portion and said cutting bit oriented to urge said bit laterally outwardly of said cutting head drum operative to cause said cutting edge to cut to a epth depth by engagement of said leading leg with the inner surface of such pipe as said cutting head drum is rotated therein. 
     
     
       2. An inside cutter for plastic pipe of a predetermined internal diameter, comprising a cutter head drum, means comprising a shaft for mounting and rotating said drum, said drum being proportioned to fit closely and freely rotatably within said pipe, said shaft and drum being coaxial, a cutting bit, said drum having guide means extending perpendicularly radially of said axis of said shaft and drum, said bit being carried in said guide means, spring means between said drum and bit urging said bit outwardly along said guide means, the bit having a bifurcated outer end portion including a cutting leg and a leading depth-control leg lying in the same plane perpendicular to said axis, the cutting leg terminating outwardly in a cutting edge disposed at the edge of the cutting leg oriented toward the depth control leg and the depth control leg terminating outwardly at a distance from said axis of between about 0.002 and 0.010 inches less than the distance of said cutting edge from said axis. 
     
     
       3. The combination according to claim 2 wherein a depth gauge drum, having a body portion proportioned to fit closely within said pipe and a flange portion of greater diameter than said body portion and greater than said internal diameter of said pipe, is disposed on said shaft spacedly from said cutting head drum, and wherein selectively operative locking means is provided on one of said drums for locking said one drum along said shaft at an adjustable distance from the other said drum. 
     
     
       4. The combination accoding to claim 2 wherein said cutting bit has opposite faces and said cutting edge is beveled from one to the other of said faces. 
     
     
       5. The combination according to claim 4 wherein the end of said leading leg is beveled in the same direction and at the same angle as said cutting edge. 
     
     
       6. The combination according to claim 2 wherein said drum includes a cover plate detachably secured thereto, said cover plate forming a portion of said guide means and, upon removal, exposing said cutting bit for removal and replacement. 
     
     
       7. In an inside the tube cutter comprising a body member adapted to be disposed and rotated on a predetermined axis in a predetermined direction inside a tube, a bifurcated cutting bit comprising a cutting leg and a leading cutting depth control leg, means slideably mounting said bit on said body member for sliding inwardly and outwardly thereof and with said legs extending outwardly of said member and lying in a plane normal to said rotational axis and with said leading leg disposed in said predetermined direction from said cutting leg, said cutting leg terminating outwardly in a cutting edge disposed outwardly a short distance beyond the outer end of said leading leg as measured radially from said axis, and spring means between said body .Iadd.member .Iaddend.and bit urging said bit outwardly from said body member. 
     
     
       8. The combination according to claim 7 wherein said mounting means mounts said bit for sliding radially with respect to said axis. 
     
     
       9. The combination according to claim 7 wherein said cutting leg extends outwardly between about 0.010 and 0.002 inches further than said cutting depth control leg as measured radially from said axis. 
     
     
       10. The combination according to claim 8 wherein said cutting leg extends outwardly between about 0.010 and 0.002 inches further than said cutting depth control leg as measured radially from said axis. .Iadd. 11. In an inside tube cutter comprising a body member adapted to be disposed and rotated on a predetermined axis in a predetermined direction inside a tube, a bifurcated cutting bit comprising a cutting leg and leading cutting depth control leg, and means slideably mounting said bit on said body member for sliding inwardly and outwardly thereof and with said legs extending outwardly of said member and lying in a plane normal to said rotational axis and with said leading leg disposed in said predetermined direction from said cutting leg, said cutting leg terminating outwardly in a cutting edge disposed outwardly a short distance beyond the outer end of said leading leg as measured radially from said axis..Iaddend..Iadd. 12. The combination according to claim 11 wherein said mounting means mounts said bit for sliding radially with respect to said axis. .Iaddend..Iadd. 13. The combination according to claim 11 wherein said cutting leg extends outwardly between about 0.010 and 0.002 inches further than said cutting depth control leg as measured radially from said axis. .Iaddend..Iadd. 14. The combination according to claim 12 wherein said cutting leg extends ouwardly between about 0.010 and 0.002 inches further than said cutting depth control leg as measured radially from said axis. .Iaddend..Iadd. 15. The combination according to claim 11 including means in contact with said bit for urging said bit radially outwardly with respect to said rotational axis..Iaddend.