| 摘要 |
A power-driven tape measure including a case having a battery chamber, a circular chamber, and an outlet communicated with the circular chamber, a motor mounted within the case, a frame enclosing the motor, an annular reel fitted within the circular chamber of the case and enclosing the frame, the annular reel having two flanges and a circular groove between the two flanges, a switch mounted on the case and electrically connected with the battery chamber of the case, the switch connected with a spring-loaded press member tending to push against the external teeth of the annular reel, a tape wound on the groove of the annular reel and having an end extending out of the outlet of the case to engage a hook, the tape being slightly larger than the groove of the annular reel in width, a driving gear fixedly mounted on the output shaft of the motor and engaged with the internal teeth of the annular reel via a gear train, and a manual gear pivotally mounted on the frame and meshed with the internal teeth of the annular reel and provided at a center with a rod extending out of the case.
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