Patent ID: 7077034

Claim:
An adjustable spanner comprising: a first jaw; a second jaw mounted for slidable movement relative to said first jaw; a locking member movable between a locking position in which it engages said second jaw so as to lock the second jaw in position relative to the first jaw and a release position in which it releases said second jaw; biasing means for biasing the locking member towards its locking position; and release means for moving said locking member out of said locking position towards its release position against the force of said biasing means; said locking member and said second jaw having interlocking ratchet teeth provided thereon; said ratchet teeth extending along opposed surfaces of the second jaw and the locking member; wherein the said opposed surfaces are parallel to the direction of movement of the second jaw; and in that said ratchet teeth are backwardly sloped relative to the opposed surfaces, such that in the event that a force is applied to the second jaw in a direction which tends to increase the separation between the jaws the teeth act to force the locking member and the second jaw further into engagement in said locking position.