| 摘要 |
A mounting spool for the measuring blade and recoil spring of a coilable rule is designed to minimize blade friction and to absorb the shock of impact when the blade is retracted and abruptly stopped. The spool comprises a circular rim having a pair of upstanding side flanges for receiving the coiled measuring blade and a side wall portion formed on one side of the rim and adapted to rotatably support the spool on the center post. The recoil spring is received inside the rim with its inner end anchored to the center post and its free end extending through an opening formed in the rim for connection to the measuring blade. A slit is formed in the flange on the side of the rim opposite to the side wall portion which extends completely through the flange and joins the opening in the rim. |
