Combustible fuel igniting apparatus

Abstract

Fuel ignitor apparatus especially adapted for use in a commercial baking oven having a plurality of fuel burner tubes susceptible of movement in response to changes in ambient temperature. The ignitor apparatus associated with each burner tube is coupled to the latter for movements therewith. Each ignitor is mounted on a wall of the oven in such manner as to enable bodily movement of such ignitor relative to the oven so as to avoid imposing bending stresses on the ignitor or the oven.

1 . In an oven assembly wherein combustible fuel is emitted from a burner tube within a combustion chamber, said burner tube being susceptible to distortion and movements in response to changes in ambient temperature, said fuel being ignitable by sparks generated by an ignition circuit having ignitor and ground electrodes spaced from one another by a spark gap and carried by a support member in such position as to locate said gap in the path of fuel emitted from said burner tube, said support member being coupled to said burner tube for movements therewith, the improvement comprising means mounting said support member in said chamber for bodily rocking movements of said support member relative to said chamber in response to and in the directions of said movements of said burner tube. 
   
   
       2 . The assembly according to  claim 1  wherein said mounting means comprises a bushing having a passage in which said support member is accommodated, means for securing said bushing to said chamber, and adjustable coupling means operable to maintain said support member in said bushing and enable pivotal movements of said support member relative to said bushing about an axis. 
   
   
       3 . The assembly according to  claim 2  wherein said coupling means comprises at least one pin in engagement with said support member and preventing movement of said support member transversely of said axis. 
   
   
       4 . The assembly according to  claim 3  wherein said pin defines said axis about which said support member is rockable. 
   
   
       5 . The assembly according to  claim 2  wherein the passage in said bushing is tapered inwardly from opposite ends of said passage. 
   
   
       6 . The assembly according to  claim 2  wherein said axis is substantially vertical. 
   
   
       7 . The assembly according to  claim 1  including at least one opening in said support member externally of said chamber and through which gas may pass into said support member. 
   
   
       8 . The assembly according to  claim 1  wherein at least one of said electrodes is knurled adjacent said gap. 
   
   
       9 . The assembly according to  claim 1  wherein said ground electrode comprises a flag having a sharp edge confronting said gap. 
   
   
       10 . An ignitor construction for use in igniting a combustible fuel, said construction comprising an elongate, tubular support member having opposite ends and being formed of electrically conductive material; electrically conductive ignitor and ground electrodes electrically insulated from one another and carried by said support member in such positions relative to one another as to establish a gap across which an electrically generated spark may jump; and swivel means mounting said support member between the ends thereof for bodily rocking movements of said support member about an axis. 
   
   
       11 . The construction according to  claim 10  wherein said swivel means comprises a bushing through which said support member extends, and including pivot means reacting between said bushing and said support member for enabling said rocking movement of the latter about said axis relative to said bushing. 
   
   
       12 . The construction according to  claim 11  wherein said bushing includes a passage therethrough, said passage flaring in opposite directions from a point between opposite ends of said passage. 
   
   
       13 . The construction according to  claim 11  wherein said pivot means comprises a pair of opposed pins carried by said bushing and extending toward one another for engagement with said support member on opposite sides of the latter, and limit means for limiting movement of said pins in a direction toward said support member following engagement of said pins with said support member. 
   
   
       14 . The construction according to  claim 10  wherein at least one of said electrodes has a knurled surface adjacent said gap. 
   
   
       15 . The construction according to  claim 10  wherein one of said electrodes comprises a flag one end of which confronts the other of said electrodes and forms with the other of said electrodes the boundary of said gap. 
   
   
       16 . The construction according to  claim 15  wherein said edge of said one of said electrodes has a sharp surface confronting the other of said electrodes. 
   
   
       17 . The combination of an elongate burner tube susceptible of distortion and movements in response to changes in ambient temperature, said burner tube having an opening therein through which combustible fuel may flow along a path, and an ignitor for igniting fuel flowing through said opening, said ignitor comprising an elongate support member supporting a spark electrode and a ground electrode spaced from one another a distance to establish therebetween a spark gap; means independent of said burner tube mounting said support member in a position alongside but spaced a selected distance from said burner tube; and means coupling said support member to said burner tube for maintaining said support member in such position that said spark gap lies in the path of fuel flowing through said opening, said mounting means enabling said support member and the electrodes carried thereby to swivel in response to said movements of said burner tube and maintain said support member at said selected distance from said burner tube. 
   
   
       18 . The combination according to  claim 17  wherein said mounting means comprises a bushing having a passage in which said support member is accommodated, and adjustable coupling means operable to maintain said support member in said bushing and enable rockable movements of said support member about an axis relative to said bushing. 
   
   
       19 . The combination according to  claim 18  wherein said coupling means comprises at least a pair of pins in engagement with said support member, said pins defining said axis and preventing movement of said support member transversely of said axis relative to said bushing. 
   
   
       20 . The combination according to  claim 18  wherein the opening in said bushing is tapered inwardly from opposite ends of said opening.