Electrical connector element
View Patent ↗An aluminum enclosure of an electronic device is used in a corrosion environment. A long-term low impedance ground connection is needed because of security and EMC reasons. While common surface protection for aluminum in corrosion environments as for example polyurethane paint is not conductive, a stainless steel connector is provided which comprises a head portion and a bolt portion. The bolt portion is inserted into a bore of the enclosure or frame. An annular rib provided on the back side of the head portion defines a cutting edge which cuts into the surface of the aluminum enclosure and provides a gas-tight electrical contact. The front surface of the stainless steel head of the electrical connector element provides a metallic surface for connecting ground wires or other conductors.
1. An electrical connector element ( 6 ) in particular for making frame connections on frames ( 5 ) or casings ( 2 ) of electrical apparatuses ( 1 ), comprising:
a corrosion resistant body having a head portion ( 8 ) of a first diameter, a front surface ( 10 ), a back surface ( 12 ) comprising a serration ( 121 ), and a threaded bolt portion ( 9 ) of a second diameter extending from the back surface ( 12 ) and aligned coaxial to a longitudinal axis ( 15 );
said first diameter being larger than the second diameter;
an annular contact rib ( 16 ) provided on the back surface ( 12 ) protruding in axial direction and surrounding said threaded bolt ( 9 );
said contact rib ( 16 ) being located coaxially to the longitudinal axis ( 15 ); and
a threaded bore ( 20 ) extending into the head portion ( 8 ).
2. An electrical connector element according to claim 1 , wherein the threaded bore ( 20 ) extends from the front surface ( 10 ) into the body and is coaxially aligned to the threaded bolt portion ( 9 ).
3. An electrical connector element according to claim 1 , wherein the threaded bore ( 20 ) extends through the head portion ( 8 ) into the bolt portion ( 9 ).
4. An electrical connector element according to claim 1 , wherein the threaded bore ( 20 ) is a dead hole.
5. An electrical connector element according to claim 1 , wherein the front surface ( 10 ) is planar.
6. An electrical connector element according to claim 1 , wherein the contact rib ( 16 ) comprises an annular cutting edge ( 19 ).
7. An electrical connector element according to claim 1 , wherein the head portion ( 8 ) comprises a means ( 13 , 14 ) for applying torque.
8. An electrical connector element according to claim 1 , wherein the back surface ( 12 ) is planar.
9. An electrical connector element according to claim 1 , wherein the contact rib ( 16 ) is triangular in cross section.
10. An electrical connector element according to claim 9 , wherein the head ( 8 ) comprises at least one facet ( 13 , 14 ) for applying a wrench.
11. An electrical connector assembly, comprising a connector element ( 6 ) according to claim 1 , an electrical wire connector ( 22 ), and a clamping screw ( 21 ) securing the wire connector against the front surface ( 10 ).
12. An electrical wire connector assembly according to claim 11 , further comprising a means ( 121 , 122 ) for preventing rotation of the electrical connector element ( 60 ) in one direction while enabling rotation of the connector element in the opposite direction.
13. An electrical wire connector assembly according to claim 12 , wherein the means ( 121 , 122 ) for preventing rotation of the electrical connector element ( 60 ) in one direction while enabling rotation of the connector element in the opposite direction comprises a serrated lock washer ( 122 ).
14. Method for providing an electrical contact surface ( 10 ) on a frame ( 5 ) or a housing ( 2 ) of an electrical apparatus ( 1 ), comprising the steps of:
providing a frame ( 5 ) or housing ( 2 ) having a metallic surface and a bore ( 7 ) therein;
inserting the connector element ( 6 ) of claim 1 into the bore ( 7 ) and tightening it in order to press the contact rib ( 16 ) into the metallic surface by plastically deforming the metallic material of the frame ( 5 ) or housing ( 2 );
applying a coating ( 23 ) on the frame ( 5 ) or housing ( 2 ) while leaving the front surface ( 10 ) of the head portion ( 8 ) free of coating.
15. Method according to claim 14 , wherein the rib provides a gas-tight interface ( 25 ).
16. Method according to claim 14 , wherein the coating ( 23 ) covers at least a portion of the circumferential surface ( 11 ) of the head portion ( 8 ).