Gas burner for cooking appliances

1. An improved gas burner for cooking appliances, comprising:

a cup-shaped lower support structure ( 11 , 12 , 13 ), adapted to be applied in a position corresponding with an opening made in the sheet metal ( 3 ) of a cooking hob;

at least two injectors ( 10 , 10 ′, 60 , 62 ), of substantially horizontal axis, applied to a lateral wall ( 16 , 31 ) of a first cavity ( 14 , 33 , 35 ) provided in said support structure ( 11 , 12 , 13 ); and

at least two substantially horizontal venturi conduits ( 8 , 8 ′, 42 , 44 ), each of them is coaxial with a corresponding injector ( 10 , 10 ′, 60 , 62 ) and having a downstream end opening into a corresponding second cavity ( 20 , 20 ′, 37 ), which is provided in said support structure ( 11 , 12 , 13 ), is open upwards, and communicates fluidly with at least one distribution chamber ( 4 , 6 ) for a combustion mixture, to generate at least one flame ring,

wherein each of said at least two venturi conduits ( 8 , 8 ′, 42 , 44 ) comprises a tubular element, which is separate from said support structure ( 11 , 12 , 13 ), is housed to undergo free axial movement within a corresponding seat ( 9 , 36 , 38 ) provided in said support structure ( 11 , 12 , 13 ), and is lockable in a desired axial position by at least one locking member ( 28 , 46 ) accessible from above said support structure ( 11 , 12 , 13 ) through said opening provided in the sheet metal ( 3 ) of the cooking hob, said at least two venturi conduits ( 8 , 8 ′, 42 , 44 ) being adjustable independently within their respective seats ( 9 , 36 , 38 ).

2. The burner as claimed in claim 1 , wherein said seat ( 9 , 36 , 38 ) for housing said venturi conduit ( 8 , 8 ′, 42 , 44 ) is cylindrical.

3. The burner as claimed in claim 1 , wherein the seat ( 9 , 36 , 38 ) for housing said venturi conduit ( 8 , 8 ′, 42 , 44 ) is provided in an interior of the support structure ( 11 , 12 , 13 ) between said first cavity ( 14 , 33 , 35 ) and said second cavity ( 20 , 37 ), the venturi conduit ( 8 , 8 ′, 42 , 44 ) bringing said first cavity ( 14 , 33 , 35 ) and said second cavity ( 20 , 20 ′ 37 ) into fluid communication.

4. The burner as claimed in claim 1 , wherein said cup-shaped support structure ( 11 , 12 , 13 ) is substantially inscribable within a circumference.

5. The burner as claimed in claim 1 , wherein said venturi conduit ( 8 , 8 ′, 42 , 44 ) and corresponding housing seat ( 9 , 36 , 38 ) extend horizontally within an overall dimension of the support structure ( 11 , 12 , 13 ).

6. The burner as claimed in claim 1 , wherein said support structure ( 11 ) comprises an injector holder cup ( 12 ) and a cover element ( 4 ) which are connected together, said seat ( 9 ) for housing said venturi conduit being defined by an elongated cavity which is provided in said injector holder cup ( 12 ) and which is closed upperly by a lower surface of said cover element ( 13 ).

7. The burner as claimed in claim 1 , wherein said support structure ( 11 ) is made in a single piece, said seat ( 9 , 36 , 38 ) for housing said venturi conduit being defined by a through cylindrical cavity.

8. The burner as claimed in claim 1 , wherein an axial length of said venturi conduit ( 8 , 8 ′, 42 , 44 ) is greater than a minimum distance between said first cavity ( 14 , 33 , 35 ) and said second cavity ( 20 , 37 ) provided in said support structure ( 11 , 12 , 13 ).

9. The burner as claimed in claim 1 , wherein said locking member ( 28 , 46 ) comprises a grub screw ( 22 ) engaged in a threaded seat provided in said support structure ( 11 , 12 , 13 ) and having a tip engaging an outer lateral surface of said venturi conduit ( 8 , 8 ′, 42 , 44 ).

10. The burner as claimed in claim 1 , further comprising a removable plug ( 24 ) applied to a wall of said support structure ( 11 , 12 , 13 ) in a position corresponding to an aperture ( 30 , 32 ) facing an end of said venturi conduit ( 8 , 8 ′, 42 , 44 ) and having dimensions such as to enable said venturi conduit to be withdrawn through said aperture.

11. The burner as claimed in claim 10 , wherein said removable plug ( 24 ) is provided with a threaded seat for engaging said corresponding injector ( 10 , 10 ′) and with a connector for a gas.

12. The burner as claimed in claim 1 , wherein at least one circular aperture ( 30 , 32 ) is provided in an outer wall ( 31 ) of said first cavity ( 33 , 35 ) for the insertion of said corresponding venturi conduit ( 8 , 8 ′, 42 , 44 ) into a corresponding seat ( 9 , 36 , 38 ) for housing said venturing conduit provided in said support structure ( 11 ).

13. The burner as claimed in claim 1 , further comprising an injector holder unit ( 52 ) removably inserted into said at least one aperture ( 30 , 32 ) provided in the support structure ( 11 ).

14. The burner as claimed in claim 13 , wherein said injector holder unit ( 52 ) comprises at least one cylindrical part ( 54 , 56 ) insertable into a corresponding aperture ( 30 , 32 ) provided in said support structure ( 11 ), said cylindrical part ( 54 , 56 ) comprising a gas connector and a member fixing at least one injector ( 60 , 62 ), said member being configured such that, when said injector holder unit ( 52 ) is fixed to the support structure ( 11 ), said at least one injector ( 60 , 62 ) is coaxial with the corresponding venturi conduit ( 42 , 44 ) housed in the respective seat ( 36 , 38 ) housing said venturi conduit.