| 摘要 |
1,226,396. Ball-point pens. F. W. BLANCHARD. 26 Aug., 1968, No. 40774/68. Heading B6P. A retractable ball-point pen is provided with means whereby air pressure exceeding atmosphere pressure is applied to the ink in the reservoir when writing pressure is applied to the writing point after the pen has been projected to writing position. As shown in Fig. 1, the pen assembly including a large diameter reservoir 226 with a follower 232, and an air vent 228, is mounted in a casing 202. Secured frictionally to the outside of the vent 228 is a member 238 of elastomeric material comprising a tubular part 240 and a cup-shaped part 242. Another member 256 with an end wall 262 and a side wall 258 surrounding the cup part 242, is attached to a rotary-type retracting mechanism 268 operated by a press-button extending through an aperture 218 in the casing. A third member 282 has a cylindrical part 284 encircling the tubular part 240, and also has a flanged part 280 engaging the side wall 258. A retracting spring 272 extends between a shoulder 276 on the casing 202 and the flanged part 280. When the mechanism 268 is operated to project the pen, the inner surface of the member 256 engages the rim of the cup part 242 so as to push the member 238 to the left and move the pen to projected position. At the same time, the spring 272 is compressed by the leftward movement of member 282 caused by the movement of member 256. When writing pressure is now applied to the pen point 224, the writing assembly can move to the right, due to the elasticity of the member 238, and causes the cup part 242 to be deformed by pressing against the end wall 262 of member 256. A volume of air is thus trapped and compressed at the rear of the air vent 228 and applies pressure to the ink. When the pressure on the point 224 is released, the cup part 242 reverts to its original shape so that the vent 228 is again connected to atmosphere. The members 256, 282 by their engagement with the cup part 242 limit the movement of the writing assembly in both directions during the application and release of writing pressure. In a modified construction (Figs. 3, 4, not shown) the pen unit is projected and retracted by operation of a press-button actuating a known wobbler type of mechanism including a wobbler element (314). According to another modified construction (Figs. 5, 6, not shown), the reservoir is enlarged at its inner end, and a member of elastomeric material and with an axial air vent is frictionally secured in the enlarged end. The elastomeric member acts in a similar manner to the member 238 to cause air pressure to be applied to the ink when pressure is exerted on the writing point. |
