| 摘要 |
<p>An external middle joint (5) for an extraction arm having two essentially identical halves (9 and 10) each of which has a connection piece (11, 12) and two leg members (14, 15 and 16, 17, respectively) projecting from the connection piece and extending on either side of a length of hose, each leg member being articulated to the corresponding leg member of the opposite joint half by means of carriage bolt connections (18, 19). The latter are formed with a bolt (20) which is non-rotationally mounted in one of the leg members (16 and 15, respectively) of the other joint half (9 and 10), and which supports a knob (21) threaded thereon. Driving members (22, 23) are mounted in a position intermediate the corresponding knob (21) and the adjacent leg member (15, 16) and are anchored in the leg member (17 and 14, respectively) in which the bolt (20) is non-rotationally mounted. Upon movement of the middle joint (5) the driving members (22, 23) and consequently the knobs (21) are imparted a movement identical with that of the associated bolt (20), whereby automatic unscrewing movements of the boltconnections (18, 19) are prevented.</p> |
