Abstract: Hoist clamp for clampingly gripping plate-shaped pieces, comprising a smooth eccentric clamping segment constituting part of a spring operated toggle lever system and co-operating with a smooth counter clamping segment which is part of a wedge, a locking mechanism comprising a rotatable circular disc of which the circumferential face acts upon the one lever of the toggle lever system, a segment of this disc having been removed to allow stretching of the toggle lever system, such that the blocking of the wedge is first released before the unlocking of the toggle lever, and said disc being further engaged by a chain guided past a guide roller and engaging at its other end the wedge against the action of a wedge spring.