A tool holder (B) for gripping and changing tools used by an industrial robot (A), said tool holder including an upstream part (C) for connection to a rotary wrist-joint (5) of a robot arm (1) and at least one downstream part (D) to be fixed to and remain integral with a tool (E1, E2 . . . ) at each tool change;
- said upstream part and each downstream part including cooperating means for the rapid assembly and locking together of said upstream part and a downstream part and for the rapid unlocking and disassembly of a previously assembled and locked together upstream and downstream parts, said cooperating means comprising;
- in the upstream part, locking and unlocking means comprised of a double acting jack unit which includes a cylinder portion (7, 71), a piston means (21, 22, 22a, 60, 72, 73) for reciprocating along an axis X--X in said cylinder portion between a locking position and an unlocking position and spring means for biasing said piston means into its locking position,
- said cylinder portion having an interior lining (10, 10a), said lining defining successively from its top to its bottom a generally cylindrical locking bore (14), a first flared slope section in the shape of a truncated cone (15), a generally cylindrical unlocking bore (16) having a diameter greater than that of said locking bore, and a second flared slope section in the shape of a female cone (70),
- said piston means comprising a head portion (22a, 72), a flange portion extending from said head portion and over a portion of said cylinder portion (7, 71), and a sleeve portion (21, 73) having a central bore with an open lower end and a top end closed by said head portion, said sleeve portion extending below said head portion and coaxial with said cylinder portion (7, 71), said sleeve portion including at least one orifice (24) and at least one ball (25) radially movable in said orifice, said ball having a diameter such that when the orifice of said sleeve portion is in registration with said lining locking bore (14) the ball extends into the central bore of the sleeve to define a locking position and when said sleeve portion is in registration with said lining unlocking bore (16) the ball may be radially withdrawn from said central bore into an unlocking position, and
- in the downstream part, a support means (30) fixedly attached to a tool for supporting a tool on said downstream part, a male cone portion (40) extending from said supporting means and cooperating with said femal cone (70) for quickly aligning said downstream part with said upstream part during assembly of said two parts, a stem (41) extending from said male cone, said stem having a double cone locking head (42) at its end opposite its end connected to said male cone, said stem being receivable into said central bore of said sleeve portion (21, 73) when said piston means is in its unlocking position;
- and
- means for forcing said piston means to its unlocking position against the bias of said spring means, said flange portion of said piston means striking said portion of said cylinder portion over which it lies when moved to its unlocking position,
- whereby said downstream part can be forced out of engagement with the upstream part by the hammer action realized as the flange portion of the piston means strikes the portion of the cylinder portion over which it lies.