Strain gauge ring for stress measurements during drilling - is fitted with centering bush which facilitates alignment of ring on work piece

摘要

The strain gauge ring for internal stress measurements during machining operations consists of three strain gauge elements arranged at 45 deg. intervals on a supporting film. The film is attached to a circuit board by an adhesive disc and connections are made between the circuit board and strain gauge elements. A steel centering bush is soldered into the centre of the conductor plate. In order to align the gauge assembly (1) with the selected position on the work piece (7) a centering pin (13) is passed through the central boring (9) of a permanent magnet clamping assembly (11) and through the bush in the centre of the strain gauge ring. The pin is removed after the ring has been fixed to the work piece and is replaced by the drill of the boring machine.