Abstract: A method and apparatus for repairing boiler tube walls by cutting out and replacing a worn or damaged section thereof involves the use of a power tool having a rotary milling head specially adapted to remove membrane material from between tube ends which are exposed when the damaged section is removed and optionally to simultaneously bevel the end of a tube as membrane material is being removed. The method and apparatus of the invention allows for the rapid and precise removal of membrane material from between the exposed tube ends to facilitate subsequent beveling and welding operations or for concurrent beveling and membrane removal, while substantially reducing the risk of weakening or damaging the tube wall by avoiding excess removal of material therefrom.

Abstract: A method for repairing boiler tube walls by cutting out and replacing a worn or damaged section thereof involves the use of a power tool having a rotary milling head specially adapted to remove membrane material from between tube ends which are exposed when the damaged section is removed. The method and apparatus of the invention allows for the rapid and precise removal of membrane material from between the exposed tube ends to facilitate subsequent bevelling and welding operations, while substantially reducing the risk of weakening or damaging the tube wall by avoiding excess removal of material therefrom.

Abstract: An apparatus for cutting boiler tubes comprising a movable carriage having a cutting means where the carriage and cutting means are supported on a lateral supporting beam secured adjacently to a bank of boiler tubes. The movable carriage means is stabilized with a plurality of bearings means for engaging the lateral beam and preventing strain and vibrations during the cutting process. The cutting means is preferably powered by a pneumatic motor.

Abstract: A portable gas operated rotary tool is provided for milling a surface on the end of a cylindrical workpiece. The tool has a motor powered by a pressurized gas, such as compresseed air. The motor directly drives a rotary milling head which is axially aligned with the axis of rotation of the motor. The motor has a stator chamber which houses a rotor having radial slots. Vanes are journaled within said slots for radial movement within the slot and define progressively expanding cavities. The milling head has a central bore for mounting on an arbor of the motor. The milling head includes blades for milling a frustoconical surface on the workpiece and a non-locking pilot tube to align the tool with the longitudinal axis of the workpiece. An air motor design is also disclosed that provides very high rotary speeds using standard air system pressure, very high horsepower, a low polar amount of inertia and low torque.

Abstract: A portable gas operated rotary tool is provided for milling a surface on the end of a cylindrical workpiece. The tool has a motor powered by a pressurized gas, such as compressed air. The motor directly drives a rotary milling head which is axially aligned with the axis of rotation of the motor. The motor has a stator chamber which houses a rotor having radial slots. Vanes are journaled within said slots for radial movement within the slot and define progressively expanding cavities. The milling head has a central bore for mounting on an arbor of the motor. The milling head includes blades for milling a frustoconical surface on the workpiece and a non-locking pilot tube to align the tool with the longitudinal axis of the workpiece. A novel air motor design is also disclosed that provides very high rotary speeds using standard air system pressure, very high horsepower, a low polar moment of inertia and a low torque.

Abstract: A portable gas operated rotary tool is provided for milling a surface on the end of a cylindrical workpiece. The tool has a motor powered by a pressurized gas, such as compressed air. The motor directly drives a rotary milling head which is axially aligned with the axis of rotation of the motor. The motor has a stator chamber which houses a rotor having radial slots. Vanes are journaled within said slots for radial movement within the slot and define progressively expanding cavities. The milling head has a central bore for mounting on an arbor of the motor. The milling head includes blades for milling a frustonconical surface on the workpiece and means to align the tool with the longitudinal axis of the workpiece.