Conventional electrical grounding methods within the automotive industry include a connection having a ring terminal held to a threaded stud with a threaded nut. The electrical contact is created between the ring terminal and the body sheet metal by applying torque to the nut which applies an axial force upon the ring terminal. Thus a reliable connection is dependent upon the amount of torque applied to the nut. Because this is controlled in the power nut driver used at the assembly plant, frequent calibration of the nut driver is required to assure compliance to the torque specification. Unfortunately, inadvertent mis-alignment of the nut to the threaded stud can cause cross-threading between the nut and the stud which will cause a false torque reading and potentially a bad connection. Moreover, tools such as a nut driver are cumbersome within a manufacturing environment and lead to increase maintenance and labor expenses.
However, a hand pluggable ground connection or terminal clip such as that disclosed in Hurdoy, U.S. Pat. No. 5,788,543, issued Aug. 4, 1998, do not require the cumbersome and costly use of calibrated tools. The disclosed terminal clip has a barrel portion sized to fit over a stud having a prescribed diameter. To mate with the stud, the terminal clip also has an activation arm which when depressed expands the barrel portion to a diameter that is larger than the diameter of the stud and therefore capable of fitting over the stud. In this expanded state the terminal is slid down the length of the stud until the top of the stud extends above the barrel portion of the terminal clip. Once aligned axially to the stud, the activation arm is released causing the barrel portion of the terminal to exert a spring induced radial force upon the stud as it tightens around the stud circumference.
Unfortunately, the exposed state of the metallic terminal clip leaves it prone to damage from adjacent obstacles. Moreover, the sharp edges and snagging interfaces of the terminal clip can snag adjacent wires causing wire insulation chaffing or which may prevent the activation arm from fully releasing after being depressed. Moreover, if the activation arm is depressed to far, the terminal clip may be inadvertently damaged via plastic deformation, loosing some of its resiliency necessary to provide a reliable electrical connection. Yet further, the activation arm is not ergonomically friendly to the user in the assembly plant and in its exposed condition is susceptible to damage due to shipping and handling.
USPTO Backgrounds
USPTO Backgrounds