Patent ID: 9500558
Filing Date: 2016-11-22
CPC Classification: G01M

Claim Text:
1. A method for measuring light tightness of a piston ring provided with a joint and which is non-round when produced whereby the joint is open with ends of the joint radially offset from each other and circumferentially offset from each other, comprising: positioning the piston ring having an open joint within an accessory device having an inner circular surface of diameter corresponding to an external diameter of the piston ring as per a configuration of the piston ring with the joint closed, clamping the piston ring having the open joint against the inner circular surface of the accessory device, applying a force to an inner circumferential surface of the piston ring along a length of the piston ring toward at least one of the joint ends, said force being applied in a radially outward direction toward the inner circular surface of the accessory device and being of at least sufficient magnitude to substantially close the joint, and detecting by optical devices whether the joint to which the force is applied is seated against the inner circular surface of the accessory device in a light-tight manner.