| 摘要 |
<p>A latch of the over centre type for use inter alia in locking together surveyors rods in order to give reproducible measurements. The latch locks together a first axially slidable member (2) and a second axially slidable member (8) in overlapping disposition; it comprises a pair of latch supporting pivots (22) extruding from the first member, on a first common axis a pair of latch fulcrum pivots (26) extruding from the second member on an axis parallel to the first axis, a latch arrester (30) extruding from the first member, a latch body (16) having a face and sides (18) which extend to or past the latch fulcrum pivots (26) each latch side having an S-shaped recess (24) to engage the associated fulcrum pivot and an elongated slot (20) to engage the elongated latch support pivot. At least one of the sides has an edge protrusion (34) which must be snapped past the latch arrester (30) to complete the latch action. The latch is captive on the first member (2) and slidable with that member to a locking position where the latch is tilted around the fulcrum pivots (26) whereupon the latch causes the distance between the two axes of the members (2, 8) to change locking them together in an over centre action, which action cannot be reversed except by snapping the protrusion (34) past the latch arrester (30).</p> |
