| 摘要 |
A blind rivet able to be anchored in material such as softwood, without the need to break through the blind face (36) of the material, comprises a tubular shell (14) and a stem (15) which extends through the shell. The shell (14) has a preformed head (18) at one end of a shank (17). An end portion (19) of the shank remote from the head (18) has a thinner wall (21) than the main, next adjacent, portion of the shank, and is thus weakened and made more easily expandible. The stem (15) has a plugging portion (28) having an expander head (29) adjacent the thin-walled end portion 19) of the shell, a breakneck (27), and a pulling portion (26) which projects from the head end of the shell. The expander head (29) increases in diameter away from the pulling portion (26), and presents a plurality of longitudinal cutting elements (24) generally towards the weakened end portion (19) of the shell. On gripping the pulling portion (26) and pulling the stem (15), the cutting elements split the end portion (19) of the shell into a plurality of legs (37), while the expander head (29) enters into the end portion (19) and forces the legs (37) outwardly. The main part of the shank (17) has a smaller diameter bore (20) than the weakened end portion (19), and resists entry of the expander head (29). |
