Automatic balancing apparatus for balancing stand

An automatic balancing apparatus for a balancing stand comprising:

• a vertical arm and a horizontal arm mounted to a joint fulcrum in a pivotal manner, said joint fulcrum being fixed to either said vertical arm or a horizontal arm;
• weights being weighed to an end side of said horizontal arm;
• a counterweight for balancing with respect to said weights being weighed to the other end side;
• a detecting mechanism for detecting unbalanced conditions of said horizontal arm;
• and
• a driving mechanism for displacing said counterweight in a balancing direction in response to signals outputted by said detecting mechanism,
• wherein said detecting mechanism is provided with:
• a gear fixed to the joint fulcrum;
• a lever pivotally supported at a middle portion thereof on said vertical arm or horizontal arm whichever not being integrally fixed to said gear, said lever further provided with at one end thereof a telescopic latch engageable with and detachable from said gear;
• a pair of stoppers opposed to each other with a predetermined clearance with the other end of said lever being sandwiched between said stoppers;
• urging means for holding the other end of the lever at a neutral position of said clearance;
• and a pair of switches provided opposed each other with the other end of the lever interposed therebetween, said switches being pushed by the other end of the lever.