| 摘要 |
<p>1,087,777. Artificial teeth. E. KOPP. Dec. 8, 1965 [Dec. 17, 1964], No. 52068/65. Heading A5R. [Also in Division B5] A pattern of a tooth stump or jaw part for use in making dental prostheses is cast from a synthetic plastic film or plate by drawing the film or plate over a model of the part. Apparatus for casting the pattern comprises a heating means and a pressing device arranged so that they may be brought to act alternately on the film or plate, which is supported so that it is vertically displaceable relative to the model. The model, e.g. in the form of a tooth stump, is supported by a kneadable composition (21) in a trough 3 on a table 2. The film is clamped in a frame 7 which is vertically displaceable, against springs 18, above the model. A radiant heating device 14 and a blowing head 17 are supported by arms 13, 22 extending from a head being rotatable relative to a column 11 so that either the heating device or the blowing head may be disposed above the frame 7. In operation, the film is plasticised by the heating device. The blowing head is then lowered against a spring by a piston or diaphragm operated by compressed air, to carry the frame 7 downwardly until the film is stretched by the model. Compressed air applied by the blowing head presses the film into intimate contact with the model.: In order to compensate for the strinkage of the pattern as it cools, a compensating film is placed on the side of the pattern film facing the model so that it is moulded with it. The moulded compensating film is removed from the pattern. The pattern is made of a material which will burn away in a casting mould, e.g. polymethacrylates or polyolefins.</p> |
