| 摘要 |
<p>A gooseneck having a generally horizontally extending tongue (2) for insertion into a socket of a semi-trailer, the tongue being provided with a protrusion (7) for cooperation with a recess provided in a socket of a semi-trailer, characterised in that the protrusion (7) is retractable relative to said tongue (2) to facilitate insertion and withdrawal of the tongue of the gooseneck into and from a said socket and is extensible relative to said tongue (2) to ensure safe coupling of the gooseneck and semi-trailer. The extension and retraction of the protrusion is preferably effected pneumatically. The invention also embraces the combinations of such a gooseneck with a semi-trailer, and with a semi-trailer and tractor. The pneumatic supply is preferably drawn from a pneumatic system of the tractor. </p> |
