发明授权
- 专利标题: Mechanical pencil with lead feed responsive to writing pressure
- 专利标题(中): 铅笔的机械铅笔响应书写压力
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申请号: US641916申请日: 1975-12-18
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公开(公告)号: US4003664A公开(公告)日: 1977-01-18
- 发明人: Kemal Butka
- 申请人: Kemal Butka
- 专利权人: Kemal Butka
- 当前专利权人: Kemal Butka
- 主分类号: B43K21/033
- IPC分类号: B43K21/033 ; B43K21/16
摘要:
A mechanical pencil, especially for thin leads, in which a tubular guide projects from and is guided for movement in axial direction in one end of a tubular casing. Lead is automatically advanced through the casing as a function of pressure exerted on the tubular guide during writing or drawing by successively compressing and expanding a tubular, resilient element having a conically-shaped end. During writing or drawing, the resilient element is compressed and its conically shaped end is wedged in tight engagement into a cooperating conically shaped end of an abutment member so as to clamp lead passing through the casing, thereby preventing the lead from moving inwardly during writing. When pressure is terminated, the resilient element is restored to its expanded condition, thereby freeing the lead to advance.