| 摘要 |
<p>The present invention relates to a telescopic support for a trailer tow bar. A rotary crank (8) is connected to a screw (1) of small diameter and small pitch itself connected to a screw (3) of larger diameter and larger pitch, by the insertion of a small nut (2), the said small nut being fixed solidly to the upper part of the large screw (3). This large screw (3) has a friction angle which is smaller than its helix angle. These two screw/nut assemblies are joined together inside two telescopic tubes (5a, 5b). A large nut (4) is arranged on the large screw (3) and is connected to a third telescopic tube (5c). An arm (7) on which is arranged a support wheel (jockey wheel) (6) is connected to the base of the lower telescopic tube (5c). <IMAGE></p> |
