| 摘要 |
PURPOSE:To prevent a grinding belt from being cut in such a way that in the captioned device to grind the cylindrical part of a boiler and the inside of a quasi-U-shaped groove of steel pipe, or another, the width of the outer peripheral part of a contact wheel can be made narrower than the width of the groove. CONSTITUTION:A contact wheel 47 is inserted into a quasi-U-shaped groove 2 of the cylindrical body 1 of a boiler to be ground. The sectional shape of the outer peripheral part of the contact wheel 47 is a teat-form, its width l is narrower than the width L of the U-shaped groove 2, and the spherical parr 47a of the outer peripheral rim is formed so that it can be hit against only the bottom part of the groove 2. In consequence, the center part of the belt 71 is pressed against the bottom of the groove 2, and the edge parts on the both sides of the belt 71 are just lightly touched the inside of the groove 2. Then, when the belt 71 is run, and also the cylindrical part 1 of the boiler is turned, the edge parts on the both sides of the belt 71 are expanded toward J direction by means of centrifugal force, and pressed against the inside of the groove 2 by means of proper thrust, so that the inside of the groove 2 can be ground. |
