| 摘要 |
481,700. Reconditioning printing- cylinders. TRIGGS, W. W. (Photo-Cylinder Corporation) May 11, 1937, No. 13360. [Classes 83 (i) and 83 (iv)] A method of salvaging spent printing-cylinders comprises expanding the cylinder to increase the outside diameter and lining the inside wall with cast metal. A spent copper cylinder 10, Fig. 3, is positioned within a die 13 having an internal diameter equal to the original diameter of the printing cylinder, a tapered expanding member 14 is forced into the cylinder to expand it, the internal key 12 being preserved in this operation and afterwards cut at 26, Fig. 4, to form a number of sections 25 which serve to anchor the cast metal lining to the cylinder. The lining, which may be of a relatively cheap metal such as zinc, is cast around a core 19, Fig. 5, in a mould 10, the core being of similar external shape and size as the mandrel on which the cylinder is normally used. A keyway 20 in the core produces a key on the lining similar to the original key 12 and so as to protect the forward end of this key, when the lining metal is relatively soft, a short steel key 27 is embedded in the cast metal lining. The latter may be heated during the casting so that the contraction on cooling increases the bond between cylinder and liner. |
