| 摘要 |
<p>The flat spanner uses a fixed (2) and a movable (3) jaw, to cover a range of nut (4) sizes, uses torque in one direction (7) to close the jaws onto the nut, and uses the reverse torque to move the jaws apart. The movable jaw may comprise a slide and may have a dovetail section tenon (11), located by an inclined groove (10) of the complementary shape. The path this follows is angled to the fixed jaw, whilst the parallelism of the active jaw faces is maintained. Reciprocal torques obtain a ratchet effect and the maximum jaw interval is not less than the length of the nut diagonal. An axle pin located by slot holes may secure the tenon in the groove, coil springs (14) may return the mobile jaw to the closed position, and alternative jaw mountings may use pin jointed straps or pins in the slot holes.</p> |
