Safety device for a lighting valve of a gas burner

2). Safety device (61) according to claim 1, characterized in that it comprises a pin element (67) arranged in an angularly fixed position and which normally prevents the depression of the starting button (36), whilst said button (36) has a longitudinal notch (76), which can be lined up with the pin element (67) in said start position, and wherein the longitudinal notch (76) can slidably receive said pin element (67) for allowing the depression of the starting button.

4). Safety device (61) according to claim 3, characterized in that the starting button (36) further includes a transversal notch (77), which crosses said longitudinal notch (76) adjacent to the step section (81) and provided for being employed by said pin element (67);

• wherein said transversal notch (77) extends for a predetermined angle and has a bottom defined by said basis section (82) and by at least one transversal ascending section (83a, 83b ) adjacent to said basis section;
• and
• wherein said predetermined angle is associated to the further rotation of the starting button (36) such that said further rotation causes the reentry of the pin element (67) in the seat (84) by said transversal ascending section with disengagement of the pin element from the transversal notch (77) in said unhooked condition.

5). Safety device (61) according to claim 1, characterized in that it is included in a starting group (68) which is mounted on a valve body (33), said group comprising an actuating stem (56) for the starting button (36) and a guide sleeve (69) for said stem (56) and in which the cutoff shutter (42) is slidably mounted on said stem and is arrested against stop elements (71) of the actuating stem by a holding spring (72) opposed by said sleeve (69).

6). Safety device (61) according to claim 3, characterized in that it is arranged in a starting group (68) comprising an actuating stem (56) for the starting button (36) and a guide sleeve (69) for said stem (56), and wherein the cutoff shutter (42) is slidably mounted on said stem and is arrested against stop elements (71) of the stem (56) by a holding spring (72) opposed by the sleeve, said seat of guide (84) being provided in the guide sleeve (69) and said radially acting spring (88) being mounted on said sleeve.

7). Safety device (61) according to claim 6, characterized in that the guide sleeve (69) comprises an annular notch (89) also defining said seat of guide (84) and in which the radially acting spring (88) is constituted by an elastic annular leaf lodged in said annular notch (89) and having a section (91) engaging in a hole of said annular notch and another section adapted to cooperate with another end of said pin element (67).

8). Safety device (61) according to claim 5, characterized in that the guide sleeve (69) is locked in a cylindrical hollow section (92) of the valve body (33). and in which there is provided a gastight “O” ring (93) interposed between an annular notch of the sleeve and said cylindrical section (92).

9). Safety device (61) according to claim (5), characterized in that it comprises a pin element (67) arranged in an angularly fixed position and which normally prevents the depression of the button (36), and wherein the starting button (36) has a longitudinal notch (76) which can be lined up with the pin element (67) in the said angular starting position,

• wherein said longitudinal notch (76) can slidably receive said pin element (67) for allowing the depression of the said button (36), and
• wherein the starting button (36) includes a hub (63) on which said notch (76) is formed, said guide sleeve (69) having a terminal section (94) with a guide for the sliding of the actuating stem (56) and a vane (96) adapted to receive a portion of said hub (63), the return spring (57) being lodged in said vane (96), around the stem, interposed between said terminal section (94) and a seat (97) of said hub (63).

10). Safety device (61) according to claim 9, characterized in that it further includes a gastight “O” ring (98), which is interposed between a gasket seat of the sleeve and said actuating stem (56) and wherein said gasket seat is obtained in said vane (96) and is opposed by the return spring (57) of the starting button (36).

11). Safety device (61) according to claim 5, characterized in that, in the hooking condition (FIG. 4C) of the starting button (36), the cutoff shutter (42) is disengaged from the stop elements (71) and closes a seat shutter (49) for the burner (16) under the action of its holding spring (72).

12). Safety device (61) according to claim 5, characterized in that the cutoff shutter (42) is formed by a gastight disk (99) in resilient material and by a spring holding disk (101), in which said gastight disk (99) includes a surface opposed by the said stop elements (71) and a hub (102), wherein said hub (102) is slidable in gastight manner along said actuating stem (56), and wherein the spring holding disk (101) is shaped for receiving an end of the holding spring (72) and provides a hole in which the hub (102) of the said gastight disk (99) is lodged.

13). Safety device (61) according to claim 5, characterized in that it is used in a lighting valve in which said control shutter (41) comprises a gastight disk (51) and a contrast head (52), wherein said gastight disk (51) is spring urged toward the position of closing and in which the contrast head is actuatable by the actuating stem (56) of the starting button (36) in its depressed position, said actuating stem (56) being spaced away from said contrast haead (52) in the hooking position at the starting button (36)