FIELD OF THE INVENTION
The present invention relates to a method of end cutting tubes. In particular the invention relates to a method of cutting stress relieved tubes to produce panels
relates to an appartus for end cutting of tubes prior to edge preparation to produce superheater and reheater panels for high pressure boiler.
BACKGROUND OF THE INVENTION
Panels of Super heater and reheaters are manufactuerd in a panel, processing machine. length of the panel, generally varies from 18m to 22m. the width of the panel normally varies from 1.5m to 1.8m depending on the tube
diameter.The outside diameter of the tubes ranges between 36mm to 63.5 mm
and the thickness from 4.5 mm to 7.1 mm. Normally, the end of the tubes in
said panels are made by gas cutting depending on the required panel, length
further, the end of the tubes are machined through a grinding oprations. this involves more time and fatigue to the operator since the manual grinding is not

always uniform. In addition to these, due to gas cutting process, the excess material gets bulged inside and outside thereby warranting a perfect grinding prior to the edge preparation. Because of the gas cutting process, tapered ends are formed after the gas cutting and exact dimensions are formed. Moreover, it creates a rough surface involving burr/slag which must be ground and cleaned prior to the edge preparation for welding. Thus, a need exists to propose a method and an appartus for smooth and uniform end cutting of the panel tubes before edge preparation for welding to produce the panels.
DE 112012004597 entitled, "Bandsaw-cutting apparatus and method for cutting a ingot", teaches a band saw-cutting apparatus, comprising an actuating drive configured to move forward and backward in a rotational direction of a sheet static gear frame halves and a controller configured to be moved by the actuator to maintain a static speed of movement of the gear frame halves wherein an ingot during relative downward movement, feeds a rotating sheet toward and below the ingot with the guiding of the static gear frame halves, wherein a regulated movement of the static gear frame halves, the ingot is cut. The apparatus can stably suppress a displacement of the sheet during cutting, thereby a stable cutting of the ingot into blocks or sample of good quality surfaces at a high cutting speed and with a prolonged life of the sheet can be achieved.

JP5151851 entitled "Saw cutting device and a cutting method" discloses a band saw cutting apparatus including a cutting table on which an ingot is horizontally placed; an endless-belt blade provided in a tensioned state between pulleys, the blade having a blade-abrasive-grain portion and a blade base; and a coolant spraying means for spraying a coolant on the blade, the band saw cutting apparatus cutting the ingot by relatively feeding the blade from above to below, the blade being driven is rotated by rotating the pulleys, wherein the pulleys are configured to be rotatable about an axis thereof in both directions, and a direction of driving to rotate the blade can be changed to cut the ingot. As a result, the band saw cutting apparatus can stably secure the quality of the ingot to be cut, increase the lifetime of the blade, and improve the productivity.
JP5045427 "Cutting method by saw cutting device", describes a band-saw cutting apparatus, in which an endless-belt blade constituted of a blade abrasive-grain portion and a blade base is tensed between multiple pulleys and in which a pair of static pressure pads having coolant injection ports for injecting a coolant to the blade are disposed at such a predetermined spacing between the pulleys as to pass the blade, so that an ingot is cut by the blade circumferentially driven by the rotations of the pulleys. The invention further describes a cutting method for the band-saw cutting apparatus. This apparatus is characterized in that the positions of the coolant injection ports of the static pressure pads are offset to the side of the abrasive-grain portion of the blade. As a result, the entire vibrations of the blade base during the cutting operation can be stably suppressed to decrease the frequencies for replacing the pads and to reduce defects on the ingot faces, which occur suddenly while the ingot is being cut.

GB 2338448 entitled "Method and apparatus for in-line cutting insulating panels to length" teaches a process in which a continuous length of a composite panel is delivered to a cutting station. A leading cross cut saw with a band saw blade and a trailing cross cut saw with a band saw cutting blade are operated to cut the panel to a desired length. The longitudinal distance between the blades is set. A first panel is aligned with the leading blade and a second panel location aligned with the trailing blade. The saws are operated simultaneously. A support roller mounted on a scissors linkage supports the panel during cutting. As the saws operate they move longitudinally in timed relation to the movement of the panel so that the production of following panel lengths is not interrupted.
OBJECTS OF THE INVENTION
It is therefore an object of the present invention to propose a method of cutting afterstress-relieved tubes to produce panels for superheater and reheater in high pressure boilers.
Another object of the present invention is to propose an apparatus for end cutting of tubes prior to edge preparation to produce superheater and reheater panels for high pressure boiler.

A further object of the present invention is toto propose a method of cutting stress-relieved to produce panels for superheater and reheater in high pressure boilers which allows uniform cutting of the tube ends for edge preparation of the tubes for welding.
SUMMARY OF THE INVENTION
Accordingly, in one aspect of the invention there is provided an apparatus for preparation of edges on both sides of the superheater and reheater panel tubes,the apparatus comprising a base plate mountable on the panel and provided with "C" clamps on both ends of the panel. A Linear Motion (LM) guide is fixed on the base plate by means of at least one pair of grub screws. An angle plate is mounted on the top of a bearing block with fastners. A bracket assembly is connected to the angle plate by means of grub screws. The hub of a cut-of machine is fitted with the bracket assembly by a solid rod. Now the longitidunal motion of the cut off machine is achieved by synchronous movement of the entire assembly consisting of the angle plate, the bracket assembly and the cut of machine.
Now the positioning is made with help of spring action provided in the panel end cutting machine. As per the inventive method the tubes are cut and prepared one after the other by the longitidunal motion of the assembly of the said assembly.

The movement on the other side is prevented by "V" groves made on the LM guide and by fixing an angle plate provided above the base plate.
BRIEF DESCRIPTION OF THE ACCOMPANYING OF THE DRAWINGS
Figure 1 Cutoff machine with a cutting unit and hub Figure 2 Shows a bracket assembly with holes.
Figure 3 Shows an angle plate with internal threads for inserting pair of grub screws.
Figure 4 Shows a linear motion guide with bearing block mounted thereon.
Figure 5 Shows a base plate with handle and a guide plate mounted at the top.
Figure 6 Shows a solid rod.
Figure 7 Shows the assembly of an end cutting machine comprising the parts of 01 to 06 so as to fix in the panel.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE PRESENT INVENTION
According to the present invention, the cutting of tubes of the panel at both ends with individual settings of item 1 to item 6 to form the assembly as per figure 7.
As shown in Fig-7, the base plate (05) is clamped to the work piece namely super heater panels, reheater panels (not shown) with "C" clamps (not shown). In one embodiment, the length of the base plate(05) is 2100mm. This diemension is derived based on the maximum width of the panel. For minimum width of the panel "C" clamps are fixed accordingly. The Linear Motion (LM) guide (4) with a bearing block (04) is fixed on the top of the base plate by means of at least one pair of grub screws (08). The angle plate (03) is mounted on the top of the bearing block (04) by the grub screws(08). The bracket assembly (02) is connected to the angle plate(03) by means of a second pair of grub screws. This connection is not visible in firgure 07. The panel end cutting machine(Ol) is connected to the bracket assembly by means of a soild rod (06).
Now, the entire apparatus can be taken by hand holding the handles provided at both ends of the base plate (05) to fix on the panel. Now the apparatus is ready for cutting operation of the tubes. After one side is completed, the assembly taken to other end of the panel to repeat the cutting operation.

According to the invention, the machining time is reduced by at least 60% and the man hour is reduced by 40% with elemination the drawbacks described in the background of the invention.

WE CLAIM :

An apparatus for end cutting of tubes delivered from a furnace after stress relieving and prior to edge preparation to produce panels of superheaters and reheaters in high pressure boilers, comprising :
- a base plate (05) mountable on the panel top with at least two "C" clamps wherein linear motion guide is fitted with bearing block for longitidunal motion along the length of the the base plate;
- an angle base plate (03) mounted on the top of the bearing block to hold a bracket assembly (02) which in turn attached to a panel end cutting machine by a solid rod (06);
- the liner motion guide (04) positioned on the base plate (05) by means of at at least one pair of grub screws (08);
- the angle plate (03) fixed by means of a second pair of grub screws (08) on the top of the bearing block (04);

the holding bracket assembly (02) including the solid rod (06) attached to the panel end cutting machine (01); wherein a handle is provided on the cutting machine (01), and wherrein a hand feeding of a cutting wheel performs the cutting operation without much effort and at a less time in a single setting for one end, and wherein the operation is repeated for the other end of the panel.