PURPOSE: To maintain the function of a movavle article pressure-sensitive diaphragm for long term by covering the peripheral edge of a mounting member at the corners of the diaphragm in a grain lifting machine or the like to thereby reduce the wear thereof due to contact with the movable article.

CONSTITUTION: A movable article pressure-sensitive diaphragm 1 is coated at its corners 6, 7 by the peripheral edges 4, 5 of a member 2 to be mounted or a member 3 for mounting on the diaphragm 1. As a result, the article does not make contact with the corners 6, 7 when fed at the peripheral edges of the diaphragm 1 to thereby prevent the decrease of the diaphragm function.