| 摘要 |
1,193,724. Making pen points; force fits. RAPIDOGRAPH Inc. 17 June, 1968 [17 Aug., 1967], No. 28658/68. Headings B3A and B3U. [Also in Division B6] A metallic carbide tubing 18 is inserted into a tubular member to form a pen point for a stylographic writing instrument by forming the carbide tubing 18 to the desired length having an outer diameter within a tolerance of Œ 0À0001 inches, forming a housing 20 within the tubular member by drilling inwardly at one end a coaxial bore 0À0003 to 0À0006 inches smaller in diameter than the outer diameter of the carbide tubing 18 and horizontally advancing the latter into the housing 20 while supporting the tubular member against horizontal movement. A 0À030 inch length of tungsten carbide tubing is bore reamed within a tolerance of Œ 0À0002 inches and its one end radiused prior to inserting it into a stainless steel holder having inner and outer diameters within a tolerance of Œ0À00025 inches. The tungsten carbide tubing is press fitted into the stainless steel holder using a mandrel, the housing 20 having been reamed to provide the precise inner diameter. |
