THREE-POINT INSIDE CALLIPER Russian patent published in 2012 - IPC G01B5/12 G01B5/24 

FIELD: measurement equipment.

SUBSTANCE: device can be used to measure and control the diameters of holes, cones and grooves. The device includes a frame in the form of a round beam; two support arms, one of the arms is fitted with a spindle and can be moved axially; an indicator connected by its spindle with the second support arm which is fixed and cannot be moved axially, the second support arm is a double-arm, and there is a spindle installed on one of its sections. Furthermore, the calliper is fitted with a spring-controlled thruster installed in the frame cavity coaxially the frame itself. One end of the thruster is interacting with the spindle while another end is jointed with the double-arm and the spring-controlled two-step joint mechanism, one end of which is jointed with one support arm and the second end is jointed to the fixed holder where the double-arm is fixed. The adjustable shoulder is installed on the first support arm coaxially the spindle of the second support arm. An additional spindle is installed on the first support arm, and the adjustable shoulder is positioned in the centre between the two spindles. Furthermore, each spindle has fulcrum blocks, and the fulcrum blocks of the first spindle have the same diameter, while the side surface of the adjustable shoulder lies in the plane which is tangent to the fulcrum blocks of the spindles. The frame is fitted with a holder.

EFFECT: expanded operational capabilities; improved operating convenience.

2 dwg