| 摘要 |
<p>An adjustable wrench has jaws (1, 2) which automatically lock up when a predetermined force is applied to the handgrips (2, 3). The jaws (1 and 2) are closed by forcing together hand grips (3 and 6) which holds pivot F against rubber stop (8) mounted in the housing (9), which in turn is mounted on brace arm (7); pivot D is moved towards brace (7), thus straightening line CDE and rotating jaw (2) and pivot C anti-clockwise about pivot B. When the jaws close on to a workpiece W, resistance is met and further movement of D towards arm (7) is arrested in favour of the over-centre linkage arms (4 and 5) whereupon eccentric cam (11) locks rod (10) against anvil (12) thus holding jaw (2). The over-centre lock on the hand grip (6) locks and is prevented from going further than just over-centre by a stop G which bears on to the inside of the hand grip.</p> |
