Patent ID: 6032847
Filing Date: 2000-03-07
Classification: B25C

Abstract:
A setting tool for driving fastening elements into a receivingmaterial by means of highly compressed gases, said setting tool having a leading end from which the fastening elements are driven, a trailing end and a driving direction from the trailing end towards the leading end, said setting tool comprising an axially extending piston guide (7, 27) with the axis thereof extending in the driving direction, said piston guide (7, 27) having a first end closer to the leading end of the setting tool and a second end, said piston guide (7, 27) forming an axially extending guiding borehole (20, 40), an axiallly extending driving piston (21, 41) located within and axially displaceable within said guiding borehole (20, 40), said driving piston (21, 41) having a head (9, 29) closer to the second end of said piston guide and a shaft extending axially from said head toward the first end of said piston guide (7, 27), means for returning said driving piston (21, 41) opposite the driving direction after a fastening element has been driven into the receiving material, said means comprising at least one spring element (11, 31) extending in the driving direction within said guiding borehole (20, 40) and encircling such shaft (8, 28), a stop (17) for said at least one spring element located within said piston guide (7, 27) intermediate first and second ends thereof and facing toward the second end of said piston guide and a surface (18) of said head extending transversely of the driving direction and facing the driving direction, said at least one spring element comprises at least one axially extending conical compressing spring having a number of individual coils each of a different diameter and being axially collapsible when a fastening element is driven by said driving piston (21, 41) so that in a driven end position the individual coils are located in a single plane within one another and are contact free relative to one another.