Sfs Stadler Ag

Sfs Industrie Holding Ag

Albert Baumgartner

Daniel Gasser

Richard Sahli

Walter Untersander

Paul Muller

A screw holder mountable on a drive unit having a tubular passage with two axially-aligned sections, each provided with locking and centering elements, such that a screw inserted into such holder can initially only penetrate until the screw head is reliably held and suspended in the first section by the locking elements. The force of the centering and locking elements upon the screw head is overcome when the apparatus is placed on the screw location and an engagement tool coupled to a drive shaft is brought into driving engagement with the screw head, which driving movement forces the locking elements radially outward in response to the axial load upon the screw head and the passage of the screw head therethrough. After the screw head passes through the first section within the tubular passage, the screw shaft is engaged by the centering elements of the second section. The centering elements of the second section are then also forced back as the head of the screw passes therethrough.

Apparatus for driving screws mountable on a drive unit

A tapping screw includes a screw head, a self-tapping thread portion and a drilling point. The drilling point has a pair of approximately axially extending flutes which are located diametrically opposite each other relative to the shank axis and include clearing surfaces and cutting surfaces. The cutting surfaces end in cutting edges facing the point of the screw and lateral outer knives. Immediately adjacent the cutting edges or cutting knives, the cutting surfaces have a convexly arched cross-sectional shape.

Tapping screw

Screw

Growing community of inventors

Kriessern, Switzerland

Albert Baumgartner