Abstract: A quickly releasable clamping lock of the knee lever type, usable to clamp a filter cover to the filter housing of an engine air intake filter, the lock assembly comprising a curved hook member whose one extremity engages the filter cover and whose other extremity is pivotably attached to a knee lever, the latter in turn, being pivotable about a pivot anchor which, like the hook member and the knee lever, is a U-shaped wire part with angled-off anchoring trunnions engaging transverse apertures in the wall of the filter housing. The pivot connection between the pivot anchor and the knee lever is formed by wire loops in the leg portions of the pivot anchor and by angled-off pivot trunnions on the wire extremities of the knee lever. Alternatively, the pivot anchor may be a U-shaped stamping with angled-off lugs in the place of the anchoring trunnions and bores in the place of the wire loops.