Abstract: A device for coupling of an implement (1) to the operating arm of an excavator, comprising an operating arm attachment (25) and a locking member (50) with a hydraulic cylinder (51) and a control unit (41) for supplying the cylinder with an operating pressure, the cylinder having double pistons (57, 58) with piston rods (52, 53) forming locking wedges, wherein the pressure area of the piston is greater on the plus side for locking than on the minus side for opening, said device also comprising implement attachment with coupling members (4, 5) and locking elements (80, 81) by means of which the implement attachment is coupled to the operating-arm attachment under the influence of the locking member, which operating-arm attachment is provided with two links (26, 27) having counter-supports (39) for cooperation with counter-supports (16, 17) on the implement attachment, the locking member thus exerting pressure on the links in order to press them against the coupling member.