| 摘要 |
<p>1,051,329. Typewriters. INTERNATIONAL BUSINESS MACHINES CORPORATION. Nov. 13, 1964 [Dec. 20, 1963], No. 46261/64. Heading B6F. In a typewriter in which characters are arranged around a cylindrical shell 5 which is axially and rotatively moved to select a character and which cylinder is swung to effect impression, an anvil 3 with a projection 4 is provided inside the shell to concentrate the mass directly behind the character to be printed and so permit the shell to be light in weight. The anvil 3 is attached to the upper end of a tube 2 secured to a tilting base 1 mounted on a carriage. Inside the tube slides an actuating shaft 10 to which the type shell 5 is removably attached by a locating stud 13 and nut 11. The lower end of shaft 10 is rotatively secured in a two-way thrust bearing 16 so that, when the type-shell is being axially set by tube 14, rack 18, pinion 19 and pulley 24, the shaft 10, which is flattened at the very bottom, may also be selectively rotated by a slotted collar 27, tube 26 and a pulley 28. Type - carriage; letter - spacing platen.- Although described in regard to a type-cylinder mounted for travel across a platen the cylinder may be transversely fixed and the platen movable in letter-spacing direction. Aligning for impression.-As the cylinder 5 is being tilted for impression it is locked and aligned in printing position by a ball 34, Fig. 7, which is cammed into a hole 30 by a cam 33 on an actuator 32 sliding in a slot 35 in the anvil 3. In an alternative arrangement the actuator is formed with a wedge which engages in the shell. Uniformity of impression; disposition of character on rotary type-member.-As shown in Fig. 5 the characters with the largest printing areas are positioned on the lower-part of the cylinder, since as the cylinder has to be raised to move these characters into printing position, the moment of inertia of the cylinder is then at its greatest. Type-cylinder construction.-The type-cylinder 5 is thin walled, it is made of metal or plastic or formed with a very thin steel shell on its inner side and a moulded plastic member on its outer side. Case-shift.-Case-shift is effected by a special movement of the cylinder to shift it axially to one half or the other as shown in Fig. 5, or to rotate it 180 degrees as in Fig. 6 (not shown).</p> |
