In checking the bore diameter and surface of cylinder 1, measuring head 2 is inserted into the cylinder by means of gear rack 3 which meshes with pinion 4, rotating about fixed axis A. If in its upward travel the measuring head encounters any obstacle (decreased bore diameter, flaw in the wall, etc.), it stops and rack 3, moving upward along stationary rod 5, compresses spring 6 and, by means of microswitch 7, switches off the electric motor of the drive. This also transmits a signal indicating that there is a flaw in the cylinder. The bore diameter is measured by the flow of compressed air through internally tapered glass indicator column 8 to measuring head 2 and out through the clearance between the head and the bore. The flow-gauge scale is graduated in units of the deviation of the actual size from the specified value.
$4016$THP,M$