# Patent

## Title
Manual service disconnect with screw cover

## Abstract

A manual disconnect includes a housing and a base attached to the housing by a fastener. The base includes primary terminals. The manual disconnect also includes a plug assembly that includes fuse terminals and a bolt cover. The plug assembly is movable relative to the base between a disconnected position wherein the fuse terminals are not engaged with respective primary terminals, and a primary circuit engaged position, wherein the fuse terminals are engaged with respective primary terminals. When the plug assembly is in the primary circuit engaged position the bolt cover is positioned to prevent the fastener from being removed from the housing. A handle or cover part of the plug assembly is then rotated to a locked position with respect to the base. Then, the plug assembly can be moved further in the insertion direction to close an interlock circuit, allowing current to flow in the primary circuit.

## Background
BACKGROUND OF THE INVENTION
This invention relates in general to structures for interrupting an electric circuit. More specifically, this invention relates to an improved manual disconnect for an electric battery in an electric circuit.
Electric batteries are used to store and supply power for various types of machines. Batteries are often used to provide power to portable electronic equipment. Unlike a power source like a generator, which may be turned off, the battery may continue to supply power as long as there is a closed circuit between its terminals. Typically, when the electronic equipment is serviced, repaired, or inspected, the circuit is opened so that there is no current flow.
Electric vehicles and hybrid vehicles may use high voltage batteries to store electric power. This power can be provided to the vehicle by an external source, such as a wall outlet, or by an internal source such as a gasoline engine or regenerative brakes. The high voltage batteries may be used to provide power to vehicle systems, such as electric drive motors that propel the vehicle. It is sometimes desirable to disconnect the high voltage batteries so that there is no high voltage current provided to any of the vehicle's systems. This can be done to avoid damage to the vehicle systems as well as to avoid injury to people. For example, in order to reduce the risk of electrocution during service of the vehicle, a technician may disconnect the battery. Alternatively, after an accident a first responder may disconnect the battery. Consequently, vehicles that include high voltage batteries may include a manual disconnect to allow the electric circuit including the high voltage batteries to be manually opened. It is desirable to have an improved manual disconnect.
SUMMARY OF THE INVENTION
This invention relates to a manual disconnect for an electric battery in an electric circuit. The manual disconnect includes a housing and a base attached to the housing by a fastener. The base includes primary terminals. The manual disconnect also includes a plug assembly that includes fuse terminals and a bolt cover. The plug assembly is movable relative to the base between a disconnected position, wherein the fuse terminals are not engaged with respective primary terminals, and a primary circuit engaged position, wherein the fuse terminals are engaged with respective primary terminals. When the plug assembly is in the primary circuit engaged position the bolt cover is positioned to prevent the fastener from being removed from the housing.
Various aspects of this invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiment, when read in light of the accompanying drawings.



BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of an electric vehicle including a high voltage battery with a manual disconnect in accordance with the invention.
FIG. 2 is a partially cut-away, perspective view of the manual disconnect, showing a base and a plug assembly in a disconnected position.
FIG. 3 is a perspective view, from below, of the plug assembly.
FIG. 4 is a view similar to that of FIG. 2, showing the manual disconnect in a connected position.
FIG. 5 is perspective view of an interlock resistor assembly of the manual disconnect.
FIG. 6 is a perspective view of the plug assembly, showing a plug housing and a handle separated.
FIG. 7 is a perspective view, from below, of the handle.
FIG. 8 is a profile side view of a lock channel of the base.
FIG. 9 is plan view, from above, of the manual disconnect with the plug assembly connected to the base.



DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, there is illustrated in FIG. 1 a schematic view of an electric vehicle, indicated generally at 10. The illustrated electric vehicle 10 includes a battery 12. The illustrated vehicle 10 is an electric vehicle, but may be a hybrid vehicle or any desired type of vehicle that includes a battery 12. The battery 12 may be a single battery or may be multiple battery cells, if desired. The electric vehicle 10 includes an electric motor 14 that is connected to drive wheels 16. A primary circuit, indicated at 18, provides current flow from the battery 12 through the electric motor 14. The illustrated electric motor 14 is one type of electric equipment that may be connected to the battery 12, and it should be appreciated that any desired electric equipment may be powered by the battery 12 through the primary circuit 18.
The electric vehicle 10 includes a manual disconnect, indicated generally at 20. The manual disconnect 20 allows a technician to open the primary circuit 18 at the battery 12, for example, when the electric motor 14 is to be serviced. It should be appreciated that the primary circuit 18 is only described in a simplified form sufficient for the understanding of the manual disconnect 20. The preferred embodiment of the invention will be described in connection with the battery 12 on the electric vehicle 10, but it should be appreciated that the invention may be used as an electric disconnect in any desired circuit.
The manual disconnect 20 includes a base 24 that is mounted to the battery 12 and a plug assembly, indicated generally at 26. The plug assembly 26 may be moved relative to the base 24 between a connected position and a disconnected position. The plug assembly 26 includes a fuse 28. When the plug assembly 26 is in the connected position relative to the base 24, current flow through the primary circuit 18 passes through the fuse 28. When the plug assembly 26 is disconnected from the base 24, the primary circuit 18 is open.
The manual disconnect 20 also includes an interlock resistor 30. The interlock resistor 30 is part of an interlock loop, indicated generally at 32. The interlock loop 32 is an electric circuit that is closed when the plug assembly 26 is connected to the base 24, and is opened when the plug assembly 26 is disconnected from the base 24. A battery control 34 monitors the status of the interlock loop 32. If the interlock loop 32 is opened, the battery control 34 shuts down electric current flow through the primary circuit 18.
Referring now to FIG. 2, a perspective view of the manual disconnect 20 is shown, partially cut-away so that internal components are visible. In FIG. 2, the plug assembly 26 is shown disconnected from the base 24 and both the primary circuit 18 and the interlock loop 32 are open.
The plug assembly 26 includes a plug housing 36 and a handle 38. The illustrated plug housing 36 and the illustrated handle 38 are both molded from plastic, but may be made of any other desired materials. The handle 38 is connected to the plug housing 36 for relative rotational movement, as will be described below. Referring to FIG. 3, a perspective view, from below, of the plug assembly 26 is shown. The fuse 28 is connected to a plug housing surface 40 by a fuse retainer 42. The illustrated fuse retainer 42 is a separate plastic piece that snap-fits to the plug housing 36 and retains the fuse 28 therebetween. However, the fuse 28 may be retained on the plug assembly 26 by any other desired fastener. The illustrated fuse 28 includes two fuse terminals, 44a and 44b. The illustrated fuse terminals 44a and 44b are male blade terminals, but they may be any desired type of electric terminal.
Referring back to FIG. 2, the base 24 includes two primary terminals, 46a and 46b. The illustrated primary terminals 46a and 46b are female terminals, but may be any desired electric terminal. The base 24 also includes a fuse cradle 48 defined in a base surface 50. As will be described below, when the plug assembly 26 is connected to the base 24, the primary terminals 46a and 46b engage the respective fuse terminals 44a and 44b. Additionally, portions of the fuse 28 and the fuse retainer 42 are located in the fuse cradle 48.
Referring to FIG. 4, a cut-away perspective view similar to FIG. 2 is shown, with the plug assembly 26 connected to the base 24. The plug assembly 26 is connected to the base 24 by inserting the plug assembly 26 into a base space, indicated generally at 52, defined by a base side wall 54. The plug assembly 26 is inserted into the base space 52 in an insertion direction 56. As shown, the fuse terminal 44a is engaged by the primary terminal 46a. Although not visible in FIG. 4, it should be appreciated that the fuse terminal 44b is engaged by the primary terminal 46b. With the fuse terminals 44a and 44b engaged by the respective primary terminals 46a and 46b, the primary circuit 18 is closed and the battery 12 is able to provide electric current to the electric motor 14.
As previously described in reference to FIG. 1, the manual disconnect 20 also includes part of an interlock loop 32. The interlock loop 32 is an electric circuit that is closed when the plug assembly 26 is connected to the base 24, and is opened when the plug assembly 26 is disconnected from the base 24. Referring to FIG. 2, the base 24 includes a base interlock connector 58. Referring to FIG. 3, the plug assembly 26 includes a complementary interlock resistor assembly 60. As best seen in FIG. 5, the interlock resistor assembly 60 includes the interlock resistor 30 connected between two resistor terminals 62a and 62b. The illustrated resistor terminals 62a and 62b are male blade terminals, but may be any desired electric terminal. The base interlock connector 58 includes two complementary terminals (not shown) that engage the resistor terminals 62a and 62b to close the interlock loop 32, as will be described below.
The process of connecting the plug assembly 26 to the base 24 will now be described in detail. As previously described, the plug assembly 26 includes the plug housing 36 and the handle 38. FIG. 6 is a perspective view showing the handle 38 separated from the plug housing 36. The illustrated plug housing 36 includes a plug housing side wall 64 that defines a handle space, indicated at 66. The illustrated plug housing 36 includes four resilient hooks 68 that project into the handle space 66. The illustrated handle 38 defines four handle slots 70. The illustrated handle 38 may be inserted into the handle space 66 by moving the handle 38 in the insertion direction 56 relative to the plug housing 36. The resilient hooks 68 are initially deflected by the handle 38, and then rebound to the engage the handle 38. Each of the resilient hooks 68 is then located in one of the handle slots 70, and the handle 38 is able to rotate relative to the plug housing 36 about a rotation axis 72 that is parallel to the insertion direction 56. It should be appreciated that the amount of relative rotation between the handle 38 and the plug housing 36 is limited by the length of the handle slots 70.
The plug housing 36 also includes a pair of resilient stops, 74a and 74b, that extend from the plug housing surface 40. The illustrated resilient stops 74a and 74b are integrally molded with the plug housing surface 40, but may be made separately, if desired. The resilient stops 74a and 74b define respective V-shaped notches 78a and 78b. Referring to FIG. 7, a perspective view from below of the handle 38 is shown. The handle 38 includes a V-shaped finger 80 extending from the underside thereof. As will be described below, the resilient stops 74a and 74b and the finger 80 cooperate to provide the technician with a tactile indication of when the handle 38 is in one of two positions relative to the plug housing 36. It should be appreciated that the handle may include a resilient stop and the plug housing may include two cooperating fingers, if desired.
The resilient stops 74a and 74b and the finger 80 are arranged so that as the handle 38 is rotated relative to the plug housing 36, the finger 80 will first engage one of the resilient stops 74a and 74b and deflect it. As the handle 38 is further rotated relative to the plug housing 36, the engaged resilient stop 74a and 74b will rebound and the finger 80 will be engaged within the respective notch 78a and 78b. To rotate the handle 38 further relative to the plug housing 36, the technician will have to apply sufficient force to deflect the resilient stop 74a and 74b. Thus, the technician will be able to feel when the finger 80 is engaged with the notches 78a and 78b. When the finger 80 is engaged with notch 78a, the handle 38 is in an insertion position relative to the plug housing 36. When the finger 80 is engaged with the notch 78b, the handle 38 is in a locked position relative to the plug housing 36. The significance of these two positions will be described below.
Referring back to FIG. 2, the handle 38 is engaged with and is in the insertion position relative to the plug housing 36. The assembled plug assembly 26 is then moved in the insertion direction 56 relative to the base 24 in order to close the primary circuit 18. The illustrated base 24 includes an optional base guide 82. The illustrated base guide 82 is a projection from the base side wall 54 that extends into the base space 52. The plug assembly 26 includes a complementary plug guide 84, shown in FIG. 3. The illustrated plug guide 84 is a slot defined by the plug housing side wall 64. When the plug assembly 26 is inserted into the base space 52, the plug housing side wall 64 will engage the projection 82 and prevent movement of the plug assembly 26 in the insertion direction 56 unless the slot 84 is aligned with the projection 82. Thus, the base guide 82 and the plug guide 84 cooperate to ensure that the plug assembly 26 is properly aligned with the base 24 during insertion of the service plug 26 into the base 24. It should be appreciated that the illustrated base guide 82 and plug guide 84 may be replaced with any desired cooperating guides.
The illustrated plug assembly 26 includes two lock tabs 86a and 86b. However, the plug assembly 26 may include a different desired number of lock tabs 86a and 86b. The illustrated lock tabs 86a and 86b are integrally molded with and extend from the handle 38. However, the lock tabs 86a and 86b may be separate components, if desired. As best seen in FIG. 2, the base 24 includes two lock channels 88a and 88b defined on the interior of the base side wall 54. It should be appreciated that, if desired, the plug assembly 26 may define the lock channels and the base may include the lock tabs.
When the handle 38 is in the insertion position relative to the plug housing 36, the slot 84 is aligned with the projection 82, and the plug assembly 26 is moved in the insertion direction 56 relative to the base 24, the lock tabs 86a and 86b enter the respective lock channels 88a and 88b. A profile side view of the lock channel 88a is shown in FIG. 8. The plug assembly 26 may be moved in the insertion direction 56 until the lock tab 86a engages a channel wall 90a, which blocks further movement of the plug assembly 26 in the insertion direction 56. At this point, the lock tab 86a is at the location 92a and the plug assembly 26 is in a primary circuit engaged position relative to the base 24. In this position, the fuse terminals 44a and 44b are engaged by the respective primary terminals 46a and 46b, and the primary circuit 18 is closed.
From the primary circuit engaged position, the handle 38 may be rotated about the rotation axis 72 in a locking direction 94. It should be appreciated that the handle 38 is rotated relative to both the plug housing 36 and the base 24, while the plug housing 36 remains stationary relative to the base 24. The handle 38 may be rotated relative to the base 24 until the lock tab 86a is in the location 96a. In the illustrated embodiment, in order to move from location 92a to location 96a the handle 38 is rotated 15 degrees. However, these locations may be positions any desired amount of rotation apart.
From location 96a, the handle 38 may be moved further in the insertion direction 56. It should be appreciated that the plug assembly 26, including both the handle 38 and the plug housing 36, move in the insertion direction 56 relative to the base 24 until the lock tab 86a is in the location 98a. At this point, the plug assembly 26 is in an interlock position relative to the base 24. The fuse terminals 44a and 44b remain engaged by the respective primary terminals 46a and 46b, and the primary circuit 18 remains closed. Additionally, the base interlock connector 58 is engaged with the interlock resistor assembly 60 to close the interlock loop 32. At this point, the battery control 34 will allow electric current to flow through the primary circuit 18.
From the interlock position, the handle 38 may be rotated about the rotation axis 72 in the locking direction 94. It should be appreciated that the handle 38 is rotated relative to both the plug housing 36 and the base 24, while the plug housing 36 remains stationary relative to the base 24. The handle 38 may be rotated relative to the base 24 until the lock tab 86a is in the location 100a. In the illustrated embodiment, in order to move from location 98a to location 100a, the handle 38 is rotated 15 degrees. However, these locations may be positions any desired amount of rotation apart.
When the lock tab 86a is in the location 100a, the handle 38 is in the locked position relative to the plug housing 36. As previously described, the finger 80 is engaged with the notch 78b. At this position, the plug assembly 26 is fully connected to the base 24, and both the primary circuit 18 and the interlock loop 32 remain closed.
The above-described process for connecting the plug assembly 26 to the base 24 described the interaction between the lock tab 86a and the lock channel 88a. It should be appreciated that the lock tab 86b has a similar interaction with the lock channel 88b. 
The previously-described process for connecting the plug assembly 26 to the base 24 may be reversed to disconnect the plug assembly 26 from the base 24. As was described, during connection of the plug assembly 26 to the base 24, the primary circuit 18 is closed first and the interlock loop 32 closed second. It should be appreciated that during disconnection of the plug assembly 26 from the base 24, the interlock loop 32 is opened first and the primary circuit 18 is opened second.
Referring back to FIG. 2, the base 24 defines a plurality of mounting points 102. As shown in FIG. 9, the illustrated mounting points 102 are blind-holes that allow threaded connectors such as bolts 104 to be used to attach the base 24 to a housing 106 of the battery 12. The illustrated base 24 includes four mounting points 102, but may include any desired number of mounting points 102. Additionally, the base 24 may be attached to the housing 106 using any other desired fastener.
The illustrated plug assembly 26 includes optional bolt covers 110. The illustrated bolt covers 110 are projections from the plug housing 36. The bolt covers 110 prevent the manual disconnect 20 from being removed from the battery 12 without first removing the plug assembly 26 from the base 24. Referring to FIG. 2, one bolt cover 110 is shown (the second bolt cover is in the area cut-away), as well as a bolt cover slot 112 defined in the base side wall 54. When the plug assembly 26 is connected to the base 24, the bolt cover 110 is located in the bolt cover slot 112. Referring to FIG. 9, the bolt covers 110 are positioned in-line with some of the mounting points 102 and prevent the bolts 104 in those mounting points 102 from being removed from the housing 106. In order to remove the covered bolts 104 from the housing 106, the plug assembly 26 must first be removed from the base 24 in order to expose the bolts 104. As previously described, this will open both the interlock loop 32 and the primary circuit 18. Thus, the electric current from the battery 12 will be interrupted before the manual disconnect 20 can be removed from the battery 12.
The principle and mode of operation of this invention have been explained and illustrated in its preferred embodiment. However, it must be understood that this invention may be practiced otherwise than as specifically explained and illustrated without departing from its spirit or scope.

## Claims

1. A manual disconnect for an electric circuit, the manual disconnect comprising:
a housing;
a base attached to the housing by a fastener, the base including primary terminals;
an interlock connector;
an interlock resistor assembly; and
a plug assembly including fuse terminals and a bolt cover, the plug assembly being movable relative to the base along an axis in an insertion direction between a disconnected position, wherein the fuse terminals are not engaged with respective primary terminals, and a primary circuit engaged position wherein the fuse terminals are engaged with respective primary terminals; and
the plug assembly being rotatable about the axis relative to the base to move the plug assembly from the primary circuit engaged position to an interlock position, wherein the interlock connector is engaged with the interlock resistor assembly and the bolt cover is positioned to prevent the fastener from being removed from the housing.

2. The manual disconnect for an electric circuit of claim 1, wherein the insertion direction is parallel to the axis of rotation.

3. The manual disconnect for an electric circuit of claim 1, wherein the plug assembly includes a plug housing and a handle attached to for relative rotational movement.

4. The manual disconnect for an electric circuit of claim 3, wherein the handle is rotated about the axis relative to the base to move the plug assembly from the primary circuit engaged position to the interlock position.

5. The manual disconnect for an electric circuit of claim 4, wherein when the handle is rotated about the axis relative to the base, the plug housing is stationary relative to the base.

6. The manual disconnect for an electric circuit of claim 1, wherein the bolt cover comprises a tab attached to the plug assembly.

7. The manual disconnect for an electric circuit of claim 1, wherein the base is attached to the housing by a plurality of fasteners, and the plug assembly includes a plurality of bolt covers and when the plug assembly is in the primary circuit engaged position each of the plurality of bolt covers is positioned to prevent one of the plurality of fasteners from being removed from the housing.

8. A manual disconnect for an electric circuit comprising:
a housing;
a base attached to the housing by a fastener, the base including primary terminals;
an interlock connector;
an interlock resistor; and
a plug assembly including fuse terminals, a handle, and a bolt cover, the plug assembly is movable in an insertion direction relative to the base between a disconnected position wherein the fuse terminals are not engaged with respective primary terminals and a primary circuit engaged position wherein the fuse terminals are engaged with respective primary terminals, wherein:
the plug housing is further movable relative to the base to an interlock position,
the interlock connector is engaged with the interlock resistor assembly, and
the bolt cover is positioned to prevent the fastener from being removed from the housing.

9. The manual disconnect for an electric circuit of claim 8, wherein the plug assembly includes a handle attached to the plug housing for relative rotational movement thereof.

10. The manual disconnect for an electric circuit of claim 9, wherein the handle is rotated about an axis relative to the base to move the plug assembly from the primary circuit engaged position to the interlock position.

11. The manual disconnect for an electric circuit of claim 10, wherein when the handle is rotated about an axis relative to the base, the plug housing is stationary relative to the base.