Operating mechanism for electrical switches and fault interrupters

Apparatus comprising:

• drive means pivotally mounted with respect to a predetermined pivot axis and being pivoted in response to a drive input;
• a spiral spring coaxial with said predetermined pivotal axis, said spiral spring having a first end coupled to said drive means;
• output member means pivotally mounted about said predetermined axis and arranged to be acted upon by a second end of said spiral spring when said spiral spring is tensioned;
• first means for stopping, latching and selectively releasing said output member means, said first means comprising at least four movable latch members that are biased in a predetermined manner with respect to said output member means and stop means for defining at least two spaced apart latch positions of said output member means that cooperate with said at least four movable latch members, said output member means and said at least four movable latch members being configured to define at least three predetermined operating positions for said output member means, said at least three predetermined operating positions being defined by the placement of said at least four movable latch members with respect to said output member means, said first means further comprising a cam movable with said drive means and including a predetermined cam surface for selectively releasing each of said at least four movable latch members at a respective predetermined position of said cam, whereby pivoting of said drive means tensions said spiral spring so as to exert force to pivot said output member means, said output member means being released for pivot movement upon each of said at least four movable latch members being selectively released.