| 摘要 |
A loft ladder which consists of a ladder, or a number of ladder sections (11 and 12) slidably mounted upon each other, and means for connecting the upper end of the ladder, or uppermost ladder section (11), to one margin (13) of a loft aperture (14) in such a way as to permit sliding and pivotal movement relative to the aperture (14), wherein each stile of the ladder or uppermost ladder section (11), is formed with inwardly directed longitudinal flanges and the connecting means includes an insert (16) fitted between the flanges so as to be captive therebetween but capable of longitudinal relative sliding movement and extending (as at 23) outwardly to a pivot, and wherein the insert (16) is provided with a recess (17) defining a cam surface (19) for co-operation with a cam member (18) located in the recess (17), the arrangement being such that during upward movement of the ladder or section (11) relative to the insert (16) the cam member (18) is urged to an inoperative position to permit free upward movement of the ladder or section (11), but during downward movement of the ladder or section (11) relative to the insert the cam member (18) is urged to an operative position in which further downward movement of the ladder or section (11) is inhibited. <IMAGE> |
