Patent ID: 7156670

Claim:
An electrical contact system for receiving an electrical earth contact, the system comprising: a shank having an external thread; a contact flange adjoining the shank, the contact flange having a contact face facing the shank; and a non-conductive polymeric cap nut having an internal thread adapted for self locking with the external thread of the shank and a sealing flange including an obtuse-angled conical recess; wherein a maximum torque of 4 Nm applied to the cap nut is operable to engage the contact between the cap nut and the contact flange, the sealing flange being elastically deformable to create a seal when the cap nut engages the contact flange at the maximum torque, the non-conductive polymeric cap nut adapted to promote an electrical contact between only the shank and the contact using the maximum torque applied to the cap nut.