| 摘要 |
<p>An anchorage (10) comprises a base member (12) of inverted channel form receiving two support strips (16) each supporting a number of downwardly projecting mushroom feet (18). The support strips are driven simultaneously between a retracted ("in phase") position and an extended ("out of phase") position by means of a hand operated rotary actuating mechanism (26). The mechanism is also connected to a sprung loaded plunger (50) designed to fit and engage a track aperture. The support strips (16) are provided with cutaway portions (22) which co-operate with spring cam surfaces (58) such that, as the support strips are moved from their innermost, retracted position towards their outermost extended position, the support strips are forced to ride upwardly drawing the mushroom feet with them.</p> |
