Method and apparatus for the surface hardening of the inner surface of tube bends

Claim 3

An apparatus as defined in claim 1, wherein the flame hardening burner is releasably replaceably connected to the mounting bracket.

Claim 4

An apparatus as defined in claim 1, wherein the mounting bracket assembly for a tube bend furthermore mounts a cooling-water pipe in the vicinity of the inner circumferential tube bend portion, the cooling-water pipe including a plurality of cooling-water discharge nozzles directed towards the inner arc tube bend surface.

Claim 5

Apparatus for continuously surface hardening by means of flame hardening the inner surface of tube bends having a constant radius of curvature comprising flame hardening means having an arcuate configuration with a constant radius of curvature generally equivalent to the radius of curvature of said tube bends, and including means for emitting flames therefrom for flame hardening the inner surface of said tube bends, and means mounting said flame hardening means and said tube bends for rotative movement relative to each other about a center generally coincident with the center of said radii of curvature, said mounting means being arranged such that said relative rotative movement causes said flame hardening means to become positioned within said tube bends with their radii of curvature generally coincident in order to effect said flame hardening.

Claim 6

Apparatus for continuously surface hardening by means of flame hardening the inner surface of tube bends having a constant radius of curvature comprising flame hardening means having an arcuate configuration with a constant radius of curvature generally equivalent to the radius of curvature of said tube bends, and including means for emitting flames therefrom for flame hardening the inner surface of said tube bends, and means mounting said flame hardening means and said tube bends for rotative movement relative to each other about a center generally coincident with the center of said radii of curvature, said mounting means being arranged such that said relative rotative movement causes said flame hardening means to become positioned within said tube bends with their radii of curvature generally coincident in order to effect said flame hardening.

Claim 7

An apparatus as defined in claim 4, wherein the flame hardening burner means includes a plurality of flame orifices radially spaced about the circumference of the burner.

Claim 8

Apparatus for surface hardening the inner surface of tube bends of a constant radius of curvature by means of flame hardening comprising a support frame, a shaft rotatably journalled in said support frame, flame hardening burner means having an arcuate configuration with a constant radius of curvature generally equivalent to the radius of curvature of said tube bends and including means for emitting flames therefrom for flame hardening said tube bends, a mounting bracket assembly mounted for rotation with said shaft and having a free end defining a circular path during rotary motion of said shaft, a stationary mounting bracket connected at one end to said support frame and having an opposite end extending radially from said shaft, said free end of said mounting bracket assembly and said opposite end of said stationary mounting bracket being spaced from the center of rotation of said shaft a distance equivalent to the radii of curvature of said tube bend and said flame hardening burner means, said flame hardening burner means being mounted to one of said free end of said mounting bracket assembly and said opposite end of said stationary mounting bracket with said tube end being mounted to the other, rotation of said shaft operating to effect relative rotative movement between said flame hardening burner means and said tube end to bring said flame hardening burner means to be received within said tube bend to effect flame hardening of the inner surface thereof.

Claim 9

Apparatus for surface hardening the inner surface of tube bends of a constant radius of curvature by means of flame hardening comprising a support frame, a shaft rotatably journalled in said support frame, flame hardening burner means having an arcuate configuration with a constant radius of curvature generally equivalent to the radius of curvature of said tube bends and including means for emitting flames therefrom for flame hardening said tube bends, a mounting bracket assembly mounted for rotation with said shaft and having a free end defining a circular path during rotary motion of said shaft, a stationary mounting bracket connected at one end to said support frame and having an opposite end extending radially from said shaft, said free end of said mounting bracket assembly and said opposite end of said stationary mounting bracket being spaced from the center of rotation of said shaft a distance equivalent to the radii of curvature of said tube bend and said flame hardening burner means, said flame hardening burner means being mounted to one of said free end of said mounting bracket assembly and said opposite end of said stationary mounting bracket with said tube end being mounted to the other, rotation of said shaft operating to effect relative rotative movement between said flame hardening burner means and said tube end to bring said flame hardening burner means to be received within said tube bend to effect flame hardening of the inner surface thereof.

Claim 10

An apparatus as defined in claim 6, wherein the mounting bracket assembly includes a guide sleeve whereby the radial extension of the mounting bracket assembly is adjustable so as to adapt the same to the radius of curvature of the tube bend.

Claim 11

Apparatus according to claim 6 wherein said flame hardening burner means is mounted to said free end of said mounting bracket assembly and wherein said tube bend is mounted to said opposite end of said stationary mounting bracket.

Claim 12

Apparatus according to claim 8 wherein said stationary mounting bracket extends radially from said shaft at an angle offset from a directly upstanding vertical position.

Claim 13

Apparatus according to claim 9 wherein said offset angle of said stationary mounting bracket is between about 10° to 20° from the vertical position.

Claim 14

Apparatus according to claim 6 wherein said tube bend is mounted to said free end of said mounting bracket assembly and wherein said flame hardening burner means is mounted to said opposite end of said stationary mounting bracket.

Claim 15

Apparatus according to claim 6 wherein said flame hardening burner means comprise a flame hardening burner and a cooling device each having an arcuate length generally equivalent to the length of said tube bend and extending through an arc having a constant radius of curvature generally equivalent to that of said tube bend, said flame hardening burner means and said cooling means being connected end to end to form a unitary member in an arrangement such that relative rotative movement between said tube bend and said unitary member operates to first bring said flame hardening burner into said tube bend followed by said cooling means.