Airtightness testing apparatus for watches

An airtightness testing apparatus for watches, comprising:

• an airtight container;
• pressure control means capable of being so operated as to pressurize or decompress the interior of said container;
• a testing stand having a seat to carry a watch to be examined inside said airtight container;
• adjusting means to move said testing stand in the vertical direction for the adjustment of the position of said stand;
• means for detecting a distortion of the to-be-examined watch which is caused by a change of the pressure inside said airtight container due to the operation of said pressure control means;
• a support assembly supporting at least part of said detecting means;
• and
• a distortion display device providing an operator with a change of distortion detected by said detecting means, characterized in that said detecting means includes;
• a light emitting element supported by said support assembly and emitting light as a luminous flux of a regular size,
• a light receiving element supported by said support assembly so as to face said light emitting element with a fixed gap inbetween and supplying a first signal corresponding to the size of the luminous flux produced from said light emitting element, and
• a movable member composed of a contact portion touching said watch and capable of vertical movement in accordance with the change of distortion of said watch and a screening plate portion accompanying said contact member to move vertically in said gap and restricting the luminous flux from said light emitting element to said light receiving element, thereby changing the size of the luminous flux received by said light receiving element, and that said distortion display device includes;
• a display circuit to indicate the change of said first signal.