FIELD

The present disclosure relates to drivers and methods for installing threaded fasteners, and more specifically to threaded fasteners in electrical applications.

BACKGROUND

The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.

Some components in high voltage electrical systems (e.g., terminals in electric vehicle traction batteries) include threaded fasteners that carry a high voltage (e.g., greater than 300 volts). In some situations, it is beneficial to construct the terminal such that fingers or other objects cannot accidently touch these fasteners. However, in some applications, it can be beneficial for these high voltage fasteners remain accessible to authorized and trained personnel for service, while still inhibiting accidental contact.

The present disclosure addresses these issues associated with high voltage threaded fastener installation.

SUMMARY

This section provides a general summary of the disclosure and is not a comprehensive disclosure of its full scope or all of its features.

In one form, a tool for driving a threaded fastener includes a driver head, a motor, and an injector. The driver head includes a spindle rotatable about an axis. A distal end of the spindle defines a plurality of drive surfaces configured to engage mating drive surfaces on the fastener to rotate the fastener about the axis. The driver head defines a fluid passage having an outlet proximate to the distal end of the spindle. The motor is drivingly coupled to the spindle to rotate the spindle about the axis. The injector is coupled to an inlet of the fluid passage and configured to feed a liquid insulator through the fluid passage. In a variety of alternate forms of the present disclosure: the spindle defines a recess configured to receive a tool engagement portion of the fastener, the drive surfaces at least partially defining the recess; the spindle defines the fluid passage and the outlet opens to the recess; the drive surfaces are disposed on walls that extend radially inward from perimeter walls of the recess; the drive surfaces are disposed on at least one protrusion of the distal end of the spindle, the at least one protrusion configured to be received in at least one recess of the fastener; the spindle defines the fluid passage coaxial with the axis; the driver head further comprises a sleeve axially translatable relative to the spindle and disposed coaxially about the spindle, the sleeve at least partially defining a mold cavity that encapsulates a tool engagement portion of the fastener; the sleeve defines the fluid passage; spindle at least partially defines the mold cavity; the sleeve includes a plurality of sleeve members that are radially movable relative to the spindle between a first radial position and a second radial position, wherein when the sleeve members are in the second radial position the sleeve members are closer to the axis than when in the first radial position and the sleeve members cooperate to at least partially define the mold cavity; mold cavity has a perimeter shape that is different than a perimeter shape of the tool engagement portion of the fastener; the drive head further comprises an injection shaft that defines the fluid passage and is axially translatable relative to the spindle, wherein the spindle is disposed coaxially about the injection shaft.

In another form, a tool for driving a threaded fastener includes a driver head and a motor. The driver head defines an injection mold cavity and a fluid conduit. The driver head includes a fastener engagement portion configured to engage a tool engagement portion of the fastener. The fastener engagement portion and the mold cavity are coaxially disposed about an axis. An outlet of the fluid conduit is open to the mold cavity. The mold cavity is configured to surround the tool engagement portion of the fastener. The motor is drivingly coupled to the fastener engagement portion to rotate the fastener engagement portion about the axis. In a variety of alternate forms of the present disclosure: the driver head includes a spindle that is rotatable about the axis, wherein a proximal end of the spindle is drivingly coupled to the motor to receive torque therefrom and a distal end of the spindle includes the fastener engagement portion and defines the mold cavity; the driver head includes a spindle and a sleeve, wherein the spindle is rotatable about the axis and the sleeve is coaxially disposed about the spindle, wherein the mold cavity is at least partially defined by the sleeve; the driver head includes a spindle and an injection shaft, wherein the spindle is rotatable about the axis and coaxially disposed about the injection shaft, wherein the injection shaft is axially translatable relative to the spindle.

In yet another form, a method of installing a threaded fastener includes aligning a driver head of a tool coaxially with the fastener, tightening the fastener by rotating a spindle of the driver head to engage and rotate a tool engagement portion of the fastener until the fastener is in an installed state, and encapsulating at least the tool engagement portion of the fastener by ejecting a liquid insulator from the driver head onto the installed fastener and allowing the insulator to solidify and form an electrically insulating cap around at least the tool engagement portion of the fastener. In a variety of alternate forms of the present disclosure: the method further includes retracting the spindle axially away from the fastener and positioning an injection shaft proximate to the tool engagement portion of the fastener, the injection shaft being coaxial with the spindle and defining a fluid conduit through which the liquid insulator is ejected; the method further includes retracting the spindle axially away from the fastener and positioning a sleeve of the driver head so that at least the tool engagement portion of the fastener is within a mold cavity that is at least partially defined by the sleeve, wherein the sleeve is movable relative to the spindle and disposed coaxially about the spindle, and wherein the liquid insulator is ejected from the sleeve, the spindle, or both the sleeve and the spindle; the sleeve is defined by a plurality of sleeve members, the method further comprising forming the mold cavity by moving the sleeve members radially inward toward the fastener.

Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.

