Patent ID: 6457624
Filing Date: 2002-10-01
Classification: B25C

Abstract:
An apparatus for the emplacement of a fastening element (4) into a placement base (6), comprising a working piston for acting on the fastening element (4) upon emplacement, said piston including a piston plate (11, 34) and a piston shaft (34) constituted of a rigid, non-deformable material, a piston guide sleeve (7), said piston plate (11, 51) being displaceable within said piston guide sleeve (7) during a working stroke (31) from a rest position into an end position, said piston plate having in a working direction a ring-shaped stop surface (37) having arranged coaxially therewith and at a spacing therefrom a ring-shaped countersurface (43) on a receiving sleeve (38, 50) which is constituted of a rigid, non-deformable material;characterized in that said stop surface (37) comprises an end surface of a sleeve (35) on the piston plate (11) concentrically surrounding the piston rod (34), said counter-surface (43) being formed by an end surface of the receiving sleeve (38, 39, 50) which is fixedly arranged on the piston guide sleeve (7), said stop surface (37) and the counter-surface (43), in said rest position, being distanced from each other by an axial length corresponding to the length of said working stroke (31), said receiving sleeve (38, 39, 50) and counter-surface (43) in conjunction with the sleeve (35) on the piston plate (11) comprising a spring chamber (44), which is arranged in a ring-shape around the piston shaft (34) of the working piston, said spring chamber having an axially rigidly fixed length in the working direction defined by the stop surface (37) and the counter-surface (43), a return device (8, 52, 53a, 53b, 54a, 54b, 55a, 57, 77) being arranged, in said spring chamber for returning the working piston (11, 34, 51) from the end position into the rest position.