Sfs Industrie Holding Ag

Kwc Ag

Helmut Oesterle

Felix Scheiwiller

Norbert Koeppel

Peter Kouwenhoven

Ferdinand F Hochstrasser

A screw ( ) is provided with a shank ( ), a head ( ) and a boring part ( ). The shank ( ) is provided with a thread ( ). The head ( ) has a shoulder ( ) disposed at an axial distance (B) from the bearing face ( ), while a portion ( ) adjoining the shoulder on the shank side is provided with a tool drive ( ). The head ( ) of the screw can therefore be seized in axially secure manner by a tool in the region of the shoulder ( ), and this tool can then simultaneously transmit the necessary torque in the region of the tool drive ( ) as well.

Screw with tamper-proof head

In a screwing element ( ) for accommodation of a fastener head ( ) of a fastener ( ) there are provided jaws ( ) for seizing the fastener head. The jaws ( ) can be axially inserted into or withdrawn from the holder ( ), wherein the jaws in the withdrawn position can be pivotably forced apart into open position. At their free end the jaws are provided with incisions ( ) and, adjoining these, with gripper-like parts ( ) jutting outwardly toward the central axis for the purpose of engaging mechanically and/or frictionally with the fastener head ( ) from behind.

Screwing element

In a screwing element (,) for accommodation of a fastener head (,) of a fastener (,) there are provided jaws (,) for seizing the fastener head. The jaws (,) can be axially inserted into or withdrawn from the holder (,), wherein the jaws in the withdrawn position can be pivotably forced apart into open position. At their free end the jaws are provided with incisions (,) and, adjoining these, with gripper-like parts (,) jutting outwardly toward the central axis for the purpose of engaging mechanically and/or frictionally with the fastener head (,) from behind.

The fitting has in each case a hydraulically operable shutoff valve (40, 42) for hot and cold water. The diaphragm-shaped closure part (56) interacts with the valve seat (52). Provided on the side opposite the valve seat (52) is a pilot control space (60) which is connected through the passage (62) to the annular channel (48) and the corresponding feedline (20). Via control lines (86'), each pilot control space (60) is connected to the outlet line (24) via an auxiliary valve (70'). The two auxiliary valves (70') are constructed on a ceramic disk valve (72) and can be operated jointly. When the auxiliary valves (70, 70') are closed, the pressure in the pilot control space (60) corresponds to the pressure in the annular channel (48), the shutoff valves (40, 42) are closed. By rotating the operating shaft (86) the two auxiliary valves (70') are opened, by which means the pressure in the pilot control spaces (60) drops. The closure part (56) is lifted from the relevant valve seat (52) and the shutoff valves (40, 42) are opened. When the auxiliary valves (70') are closed by rotating the operating shaft (86), the pressure in the pilot control spaces (60) rises again, by which means the shutoff valves (40, 42) are closed. The joint operation of both shutoff valves (70, 70') requires extremely little energy.

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Feldkirch, Austria

Helmut Oesterle