| 摘要 |
493,401. Bending wood. MICHAELIS, K. Nov. 8, 1937, Nos. 30580, 30581, and 30582. Convention dates, Nov. 14, 1936, Aug. 14, 1937, and Sept. 29, 1937. [Class 145 (ii)] Sheets of wood are first rendered temporarily flexible by applying heat to that side which after bending is the inner side and is then forced around and into contact with a mould surface curved in one direction. The sheet 8, Fig. 1, is heated on one side by an electric or other heater 5 and its end is secured by a clamp 7 to a cylindrical mould 3 mounted on an axis 2 and rotated, when the sheet is sufficiently flexible, by a weighted arm 9. Rollers 6 prevent the sheet from lifting, the inside of the mould may be heated by a heater 4. The heater 5 may be flexible and may also move with the wood round the mould. The wood may be secured to an arm by which it is drawn around a stationary cylindrical mould. The edge of a wood sheet may be fixed to the mould which is then rolled on to the sheet. Two such moulds may be applied to a sheet so as to bend it in opposite directions. In a modification, Fig. 7, the inside of the sheet may be heated from the chamber 87 supplied with hot gas or steam or by jets 85, 86 carried by the rotatable mould which may also be heated. Springs, motors or gearing may be used instead of weights for rotating the molds. |
