Actuation attachment for electrical controlling and signalling devices, particularly for emergency circuit breakers

Claim 1

An actuation attachment for an electric controlling or signalling device, comprising a tubular housing having an inner wall defining a central axis; a sleeve arranged in said housing for movement along and around said central axis, the sleeve having two opposite ends and a jacket formed with two radially directed openings; a cylindrical slider arranged in said sleeve for movement along and around said central axis, the slider having two opposite ends and a jacket formed with an axially directed slot diverging towards one of said ends, said slider being coupled to the sleeve for joint rotation therewith and for an axial movement either relative to or in conjunction with the sleeve; locking means arranged in said slot of the slider and being spring biased to project through said openings in said sleeve; first and second axially directed guiding means formed one above the other in the inner wall of said housing to guide said locking means, said first guiding means being provided at their lower ends with inclined stopping surfaces for engaging said locking means when said sleeve and said slider are in a rest position, said second guiding means being provided at their upper ends with radially directed stopping surfaces for holding via said locking means said sleeve and said slider in an actuated position, said second guiding means being further provided with axially directed curved run on surfaces for disengaging said locking means from said radially directed stopping surfaces when the slider is turned around said center axis; an actuation member arranged in said housing below one end of said sleeve, said actuation member being movable along said center axis between a rest position in which it is disengaged from an electric controlling or signalling device, and an actuated position in which it activates said device; a holding member secured to one end of said slider and slidably guiding and supporting said actuation member; an outer pressure spring arranged between said housing and a second end of said slider to urge the slider into said rest position; an inner spring arranged between said second end of the slider and a second end of said sleeve to displace by snap action the sleeve and slider thereby forcing said actuation member into said actuated position when the slider is depressed by an operator beyond a point at which said locking means disengage said inclined stopping surfaces.