MIGUEL A ROJAS CONCEPCION
Electrician at Cairnsean St, Houston, TX

4256288, Mar 17, 1981

Aug 3, 1979

6/063444

Miguel E. Rojas - Houston TX

B23K 710

266 70

In one exemplar embodiment, a portable hole cutting apparatus for cutting circular bolt holes in metal plate and the like is disclosed having a base, and a generally upright frame to which is attached a yoke carrying a pair of vertically spaced-apart bearings mounted for rotation in the yoke, and a vertically oriented elongated drive tube journaled for rotation in the bearings. A drive means such as a manual crank, or an electric, hydraulic or pneumatic motor is mounted on the frame and through a reduction gearbox and a chain or belt driving means drives a sprocket or pulley mounted on the top end of the drive tube by means of a chain or belt. Attached to the lower end of the rotatable drive tube is a bracket that rotates with the drive tube. A cutting torch is mounted on a holding bar which is slideably attached to the bracket for permitting the cutting torch to be positioned laterally for varying the radius of the circular holes to be cut. A circle center marking rod is disposed concentrically through the drive tube and cooperates therewith for permitting the marking rod to be lowered to mark the center of the circle to be cut, and to be raised to a position not interfering with the torch during the circle cutting process.