Safety device for a lighting valve of a gas burner

A safety device (61) for a lighting valve (23) of a gas burner (16), comprising a starting button (36) and a return spring (57) for the starting button, said device being characterized in that it further comprises

• a hub (63), associated with the starting button (36) and having an annular shoulder (78), a longitudinal notch (76) which interrupts said annular shoulder and a transversal notch (77) which crosses said longitudinal notch;
• a contrast element (67) arranged on the trajectory of depression of the hub (63) so as to normally prevent the depression of the button (36) and in which said longitudinal notch (76) can be lined up with the contrast element (67) for a predetermined angular start position of the button (36) so as to allow the depression of the said button (36);
• a hooking section (81) in said longitudinal notch (76) engageable by said contrast element (67) to hold back in a hooking condition said button (36) against the action of the return spring (57);
• and
• an unhooking section (ascending sections 83a and 83b) in said transversal notch (77) engageable by the contrast element in response to a further rotation of the starting button (36) for an action of disengagement from the hooking section (81) which allows the lifting of the starting button (36) by the return spring (57).

Safety device (61) for a lighting valve (23) according to claim (15) further comprising a control shutter (41) which is actuatable through the starting button (36), a holding electromagnet (54) for said shutter depending on the pilot light and a cutoff shutter (42) depending on the starting button (36) and arranged upstream of the burner (16), the said device being characterized in that

• the depression of the starting button (36) allowed by the longitudinal notch (76) ensures the opening of the control shutter (41) for the lighting of the pilot light;
• and
• the hooking condition puts the starting button (36) in an operational state in which the cutoff shutter (42) is closed and the control shutter (41) is open under the control of the holding electromagnet (54);
• the lifting of the button (36) by the return spring (57), after the unhooking, ensuring the opening of the cutoff shutter (42) for the flowing of the gas to the burner (16) and under the control of the pilot light.