The device has a guide bushing (5), and a dial indicator (1) is installed in the upper part, secured with a screw (2). Inside the bushing there is a long rod, which contacts a short rod (10), resting against the mushroom (9) of the tee (6) of the bore gauge head. In the tee there is an engine (4) and a replaceable measuring rod (8), secured in the tee with a nut (7). On the side of the movable pin on the tee there is a centering bridge 5, which serves to set the indicator head according to the diameter of the hole. When measuring holes, the engine (4) with a spiral spring (11) presses on the mushroom (9) and through the rod (10) transmits movement to the long rod to the indicator.
1. Dial indicator. 2. Screw. 3. Handle. 4. Engine. 5. Centering bridge. 6. Tee. 7. Nut. 8. Measuring rod. 9. Mushroom. 10. Rod. 11. Spiral spring.The deviation of the size is determined by the movement of the indicator arrow. Before measuring, the bore gauge is set to the nominal size on the ring or block of tiles.
Indicator bore gauges are produced with measurement limits: 6-10; 10-18; 18-35; 35-50; 50-100; 100- 160; 160-250; 250-450 mm. For measurement, replaceable washers and rods are attached to the bore gauge, differing from each other by 1 or 5 mm (depending on the measurement limit). The washers are installed into the hole of the head tee.
(Material is located on the source website: Renaultbook.ru)