Glow plug adn heater assembly therefor with an improved connection between a central electrode and a heater probe of the heater assembly

Abstract

A glow plug has an annular metal shell and a heater assembly including a central electrode and a heater probe. The metal shell is configured to receive the heater assembly therein. The central electrode has an elongate body extending between a terminal end configured for electrical communication with a power source and an attachment end. The heater probe has an elongate body extending between a proximal end and a free distal end. Either the attachment end of the central electrode or the proximal end of the heater probe has a recessed pocket with a tapered inner surface converging axially extending axially therein. The other of the attachment end of the central electrode or the proximal end of the heater probe has a tapered outer surface configured for receipt in the recessed pocket.

1 . A glow plug, comprising:
 an annular metal shell with a central cavity;   a central electrode having an elongate body extending between a terminal end configured for electrical communication with a power source and an attachment end;   a heater probe having an elongate body extending between a proximal end and a free distal end; and   wherein one of said attachment end of said central electrode or said proximal end of said heater probe has a recessed pocket extending axially therein, said recessed pocket having a tapered inner surface converging axially into one of said attachment end or said proximal end, and the other of said attachment end of said central electrode or said proximal end of said heater probe has a tapered outer surface configured for receipt in said recessed pocket.   
   
   
       2 . The glow plug of  claim 1  wherein said central electrode has said recessed pocket and said heater probe has said tapered outer surface. 
   
   
       3 . The glow plug of  claim 2  wherein said tapered inner surface and said tapered outer surface mate with one another to axially align said central electrode with said heater probe. 
   
   
       4 . The glow plug of  claim 2  wherein said tapered outer surface has an electrically conductive outer surface configured for electrical communication with said tapered inner surface of said central electrode. 
   
   
       5 . The glow plug of  claim 4  wherein said heater probe has a substantially straight cylindrical outer surface extending from said tapered outer surface, said substantially straight cylindrical outer surface having an electrically conductive outer region configured for electrical communication with said shell. 
   
   
       6 . The glow plug of  claim 5  wherein said heater probe has an electrical circuit extending from said electrically conductive outer surface to said electrically conductive outer region. 
   
   
       7 . The glow plug of  claim 1  wherein said tapered inner surface of said recessed pocket is frustroconical in shape. 
   
   
       8 . The glow plug of  claim 1  wherein said recessed pocket is formed by an annular wall having an outer surface radially outward of said tapered inner surface, said outer surface being tapered at a different angle than said tapered inner surface. 
   
   
       9 . The glow plug of  claim 8  wherein said annular wall extends from one of said attachment end or said proximal end to a base of said recessed pocket, said annular wall having one thickness adjacent said base and another thickness adjacent one of said attachment end or said proximal end, said one thickness being greater than said another thickness. 
   
   
       10 . The glow plug of  claim 9  wherein said thickness of said annular wall varies continuously extending from one of said attachment end or said proximal end to said base. 
   
   
       11 . A heater assembly for a glow plug, comprising:
 a central electrode having an elongate body extending between a terminal end configured for electrical communication with a power source and an attachment end;   a heater probe having an elongate body extending between a proximal end configured for attachment to the attachment end of the central electrode and a free distal end; and   wherein one of said attachment end of said central electrode or said proximal end of said heater probe has a recessed pocket extending axially therein, said recessed pocket having a tapered inner surface converging axially into one of said attachment end or said proximal end, and the other of said attachment end of said central electrode or said proximal end of said heater probe has a tapered outer surface configured for receipt in said recessed pocket.   
   
   
       12 . The heater assembly of  claim 11  wherein said central electrode has said recessed pocket and said heater probe has said tapered outer surface. 
   
   
       13 . The heater assembly of  claim 12  wherein said tapered inner surface and said tapered outer surface mate with one another to axially align said central electrode with said heater probe. 
   
   
       14 . The heater assembly of  claim 12  wherein said tapered outer surface has a conductive outer surface configured for electrical communication with said tapered inner surface of said central electrode. 
   
   
       15 . The heater assembly of  claim 14  wherein said heater probe has a substantially straight cylindrical outer surface extending from said tapered outer surface, said substantially straight cylindrical outer surface having an electrically conductive outer region. 
   
   
       16 . The heater assembly of  claim 15  wherein said heater probe has an electrical lead extending from said electrically conductive outer surface to said electrically conductive outer region. 
   
   
       17 . The heater assembly of  claim 11  wherein said recessed pocket is formed by an annular wall having an outer surface radially outward of said tapered inner surface, said outer surface being tapered at a different angle than said tapered inner surface. 
   
   
       18 . The heater assembly of  claim 17  wherein said annular wall extends from one of said attachment end or said proximal end to a base of said recessed pocket, said annular wall having one thickness adjacent said base and another thickness adjacent one of said attachment end or said proximal end, said one thickness being greater than said another thickness. 
   
   
       19 . The heater assembly of  claim 18  wherein said thickness of said annular wall varies continuously from one of said attachment end or said proximal end to said base.