| 摘要 |
<p>The wing mirror is held on a jointed arm (2, 3) with a swivel joint to allow the mirror to swing back when struck. Fine adjustment is also provided by this joint. The two halves of the joint are held together by a spring (15) which pulls the conical joints into a friction hold. A ridge (20) on one joint half presses against the other half to pull the conical faces out of contact to release the joint. The ridge is normally set opposite to a groove (21) in the other part of the joint to allow the conical faces to contact. The groove is longer than the ridge so that some fine adjustment is possible without releasing the joint.</p> |
