Screw-driving device

A screw-driving device which is adapted to be coupled to a screwdriver and continuously drive screws held in a screw-holding tape in line one by one during a pressure stroke, which comprises:

• a tubular casing coupled to said screwdriver;
• a slide member slidably fitted for reciprocating movement in said casing;
• a return spring means for returning said slide member to its initial extended position during a return stroke;
• a mechanism provided in said slide member for feeding said screw-holding tape by one-step pitches corresponding to the distances between the adjacent screws on said tape,
• said screw-holding tape-feeding mechanism including:
• a guide slot means provided in said casing;
• a two-arm lever means having a pin fitted into said guide slot at the end of one arm of said two-arm lever and pivotally connected to said slide member;
• a pawl member pivotally connected to the end of the other arm of said two-arm lever and engageable in one of grooves or apertures at one lateral edge of said screw-holding tape by a spring means;
• and
• a further pawl member pivotally connected to said slide member and engageable in one of further grooves or apertures at one lateral edge or the opposite lateral edge of the screw-holding tape by a spring means,
• said guide slot means including an inclined section which causes said two-arm lever means to be pivotally moved so that said pawl member of said two-arm lever is returned over said screw-holding tape held by said further pawl member by one pitch during said pressure stroke and feeds said screw-holding tape by one pitch during said return stroke.