Friction linear guide rail assembly for boiler tube cutting apparatus

Abstract

A guide rail assembly for securement of a tube cutting apparatus for cutting of boiler tube walls to a fixed point on a tube wall, while allowing lateral repositioning of a cutting tool relative to the tube wall. The assembly includes a guide rail having a convex surface along which a carriage having a cutting device may be fixedly positioned by mating friction engagement of a concave surface of pairs of linear guide blocks secured to the carriage with the convex surface of the guide rail.

1 . A guide rail assembly including a tube cutting device, comprising:
 at least one guide rail comprising a first elongated rail shaft and a second elongated rail shaft fixed at a distance and being substantially parallel to each other along a longitudinal axis of the guide rail;   a carriage assembly operatively connected to the at least one guide rail, wherein the carriage assembly comprises at least one guide block fixed to the carriage assembly that engages the first rail shaft and at least one guide block fixed to the carriage assembly that engages the second rail shaft;   a hinge bracket operatively and movably mounted to the carriage assembly; and   a cutting device comprising a cutting blade connected to the hinge bracket, wherein in a first position with weight of the cutting device supported to reduce pressure on the guide blocks, the guide blocks are slidably movable along the first and second rail shafts, and in a second position the cutting device weight exerts downward pressure on the hinge bracket and lateral movement of the carriage assembly along the first and second guide rail shafts is substantially prevented due to a friction fit between the first and second shafts and the at least two guide blocks.   
   
   
       2 . The guide rail assembly according to  claim 1 , wherein the carriage assembly is free of wheels that contact the at least one guide rail. 
   
   
       3 . The guide rail assembly according to  claim 2 , wherein the hinge bracket is mounted to the carriage through a lug bolt connected between hinge lugs connected to the carriage assembly, and wherein the cutting device is movable in a horizontal plane in relation to the carriage. 
   
   
       4 . The guide rail assembly according to  claim 2 , wherein the at least one guide block engaging the first rail shaft has a surface having a shape complementary to a guide surface of the first rail shaft, and wherein the at least one guide block engaging the second rail shaft has a surface having a shape complementary to a guide surface of the second rail shaft. 
   
   
       5 . The guide rail assembly according to  claim 4 , wherein the guide surfaces of the first rail shaft and second rail shaft each have a convex shape, and wherein the at least one guide block engaging the first rail shaft has a concave surface which forms a friction fit with the first rail shaft guide surface and the at least one guide block engaging the second rail shaft has a concave surface which forms a friction fit with the guide rail guide surface in the second position that fixedly connects the carriage assembly to the guide rail against linear movement. 
   
   
       6 . The guide rail assembly according to  claim 5 , wherein the carriage assembly includes two guide blocks that engage the first said shaft and two guide blocks that engage the second said shaft for guiding the carriage assembly along the guide rail. 
   
   
       7 . The guide rail assembly according to  claim 1 , wherein the at least two guide blocks comprise an inner concave waist which extends outwardly to a first flange and a second flange. 
   
   
       8 . The guide rail assembly according to  claim 7 , wherein the first rail shaft and second rail shaft each comprise convex surfaces, and wherein in the second position the convex surfaces of the first rail shaft and second rail shaft contact the inner concave waist of the at least two guide blocks to prevent lateral movement of the carriage assembly. 
   
   
       9 . A guide rail assembly including a tube cutting device, comprising:
 a guide rail having a longitudinal axis and two rail shafts secured in parallel along the longitudinal axis in channels of the guide rail, the shafts providing a guide rail track having upper and lower substantially convex surfaces; and   a carriage comprising a base, a first support bar mounted on an upper portion of the base, a second support bar mounted on a lower portion of the base, at least one guide block fixedly connected to the first support bar and at least one guide block fixedly connected to the second support bar, wherein the guide blocks each have an inner concave waist located between flanges, and wherein the inner concave waist of the guide block connected to the first support bar is selectively engagable within the upper convex surface of the rail shaft and the inner concave waist of the guide block connected to the second support bar is selectively engagable with the lower convex surface of the rail shaft so that the carriage is locked in relation to the guide rail by the weight of a cutting device operatively connected to the carriage through a hinge bracket.   
   
   
       10 . The guide rail assembly according to  claim 9 , wherein the carriage is free of wheels that contact the guide rail track upper and lower substantially convex surfaces. 
   
   
       11 . The guide rail assembly according to  claim 10 , wherein the hinge bracket is mounted to the carriage through a lug bolt connected between hinge lugs connected to the carriage base, and wherein the cutting device is movable in a horizontal plane in relation to the carriage. 
   
   
       12 . The guide rail assembly according to  claim 11 , wherein two guide blocks are connected to the first support bar, and wherein two guide blocks are connected to the second support bar and each selectively engagable with the respective convex surfaces of the rail shaft. 
   
   
       13 . A guide rail assembly including a tube cutting device, comprising:
 a guide rail having a longitudinal axis and two rail shafts secured in parallel along the longitudinal axis in channels of the guide rail, the shafts providing a guide rail track having upper and lower substantially convex surfaces; and   a carriage comprising a base, a first support bar mounted on an upper portion of the base, a second support bar mounted on a lower portion of the base, at least one guide block fixedly connected to the first support bar and at least one guide block fixedly connected to the second support bar, wherein the guide blocks each have an inner concave waist located between flanges, and wherein the inner concave waist of the guide block connected to the first support bar is selectively engagable within the upper convex surface of the rail shaft and the inner concave waist of the guide block connected to the second support bar is selectively engagable with the lower convex surface of the rail shaft so that the carriage is locked in relation to the guide rail by the weight of a cutting device operatively connected to the carriage through a hinge bracket, wherein a first end of the hinge bracket is operatively connected to the carriage assembly base, wherein a second end portion of the hinge bracket is capable of moving in a radial direction with respect to the first end, and wherein the cutting device is connected to the second end portion of the hinge bracket.   
   
   
       14 . The guide rail assembly according to  claim 13 , wherein the carriage is free of wheels that contact the guide rail track upper and lower substantially convex surfaces. 
   
   
       15 . The guide rail assembly according to  claim 14 , wherein the hinge bracket is mounted to the carriage through a lug bolt connected between hinge lugs connected to the carriage base, and wherein the cutting device is movable in a horizontal plane in relation to the carriage. 
   
   
       16 . The guide rail assembly according to  claim 14 , wherein two guide blocks are connected to the first support bar, and wherein two guide blocks are connected to a second support bar and each selectively engagable with the convex surfaces of the rail shaft. 
   
   
       17 . The guide rail assembly according to  claim 16 , wherein the carriage is free of a brake comprising a shoe or pad that locks the carriage to the guide rail other than said guide blocks. 
   
   
       18 . The guide rail assembly according to  claim 17 , wherein a friction fit between the guide rail convex surfaces and the guide blocks substantially prevents movement of the carriage on the guide rail.