Patent Description:
A battery module has multiple battery cells with terminals that are electrically connected to one another to provide a more powerful battery than the individual cells would otherwise provide. One common type of electrical connection is a cable having terminal rings at opposing ends. Each terminal ring is bolted to one of terminals of one of the cells. Another common type of electrical connection is a bus bar that is bolted to the cells in a similar manner to that of the cable. Publication <CIT> discloses a cover for an electrical connection device. The cover includes a pair of cover elements which are provided with receptacles for accommodating connection members of a battery connection terminal, and hollow connection portions which are slidably fitted so as to adjust the length of the cover. The connection portions can be opened, and the receptacles are provided with lids. After the connection portions are opened and partly assembled, the battery connection terminal is inserted into the cover sideways. Then, the connection portions are closed. The assembly of the cover and the terminal is fitted such that battery posts are inserted into insertion holes formed in the connection members, and the lids are closed after nuts are fastened to the battery posts. When a distance between the battery posts is changed, a corresponding battery connection terminal is prepared and the length of the cover is adjusted by sliding the connection portions with respect to each other. Accordingly, a slight change in the distance between the posts can be offset by the length adjustment of the woven wire and the cover. Publication <CIT> discloses a power connector system includes a female connector and a male connector. The female connector includes a female terminal in a female housing. The female terminal is in the form of a U-shaped channel defining a recess. A U-shaped contact member in the channel recess forms a second recess. The male connector includes a male terminal in a male housing. The male and female housings are releasably connected together with the male terminal extending into the recess in the contact member. Publication <CIT> discloses an electrical connector, comprising: a first housing having a first electrical terminal; and a second housing configured to mate with the first housing, the second housing including a protective shroud and a second electrical terminal disposed within the protective shroud, the protective shroud having a front side, a back side aligned parallel to the front side, a first wall aligned orthogonal to both the front side and the back side, and a second wall aligned parallel to the first wall, the front side defining a first opening that exposes a leading edge of the second electrical terminal, the back side including an extension aligned perpendicular to the back side, the extension defining a second opening that exposes a portion of a trailing edge of the second electrical terminal, the protective shroud defining a terminal slot extending from the second opening to the first opening and bounded by the first wall and the second electrical terminal, the terminal slot configured to receive the first electrical terminal, wherein when the first housing is mated with the second housing the first electrical terminal is disposed within the terminal slot in electrical and physical contact with the second electrical terminal and the first wall and the extension stabilize the first electrical terminal, wherein the extension is configured to inhibit a standard probe configured to simulate a human finger from contacting the trailing edge of the second electrical terminal when the electrical connector is in an unmated condition.

<CIT> discloses a battery module according to the preamble of independent claim <NUM>.

The type of battery module used in, for example, automotive applications provides significant electrical energy. It is desirable to design a system for electrically connecting and disconnecting the cells in a manner that is safe for the battery module assembly and/or service technicians.

The embodiments, examples and alternatives of the preceding paragraphs, the claims, or the following description and drawings, including any of their various aspects or respective individual features, may be taken independently or in any combination. Features described in connection with one embodiment are applicable to all embodiments, unless such features are incompatible.

A battery module <NUM>, or battery pack assembly, is schematically illustrated in <FIG>. The battery module <NUM> includes multiple battery cells <NUM> with positive and negative electrical terminals 14a, 14b (generally referred to as "terminal <NUM>"). The terminals <NUM> of the various cells <NUM> are electrically and mechanically connected to one another with bus bar assemblies <NUM> in a configuration that provides sufficient power for large electrical loads, such as automotive hybrid propulsion systems.

Referring to <FIG>, <FIG>, the terminal <NUM> is provided by male terminal provided by a quadrangular copper plate. It should be understood that the terminal <NUM> may be configured differently, for example, as a female terminal. There is a potential shock hazard when the terminal <NUM> is left exposed. To mitigate the shock hazard when connecting and disconnecting the bus bar assembly <NUM> from the cells <NUM>, a nonconductive terminal cap <NUM> is secured to a battery housing <NUM> by a connection <NUM> (<FIG>), for example, snaps. The terminal cap <NUM> may also be integrally formed with the battery housing <NUM>, for example, during a plastic molding process.

As shown in <FIG>, the bus bar assembly <NUM> includes a bus bar <NUM> (<FIG>, <FIG> and <FIG>) substantially enclosed by a nonconductive shroud <NUM>. The bus bar <NUM> has an end <NUM> provided by a female terminal that mechanically and electrically engages and mates with the male terminal <NUM> in an assembled condition.

The nonconductive terminal cap <NUM> at least partially surrounds the terminal <NUM>. In the example, a U-shaped perimeter wall <NUM> circumscribes at least a portion of the terminal <NUM>, for example, on three sides, to provide a gap <NUM> configured to expose the terminal <NUM> in order to receive the end <NUM>.

The terminal cap <NUM> also has a post <NUM> that receives the terminal <NUM> and is arranged interiorly of the perimeter wall <NUM>. The terminal <NUM> has a perimeter edge <NUM> bounding opposing faces <NUM> of the terminal <NUM>. The post <NUM> extends outward from a base of the terminal cap <NUM> and provides an E-shaped configuration with the perimeter wall <NUM>. In the example, the post <NUM> surrounds the perimeter edge <NUM> but leaves at least one of the faces <NUM> exposed. In this manner, the post <NUM> shields at least the end of the terminal <NUM> from contact. The perimeter wall <NUM> extends beyond the terminal <NUM> and beyond the post <NUM> to further isolate the terminal <NUM>. The perimeter wall <NUM> and the post <NUM> cooperate to provide the gap <NUM> as "finger-proof," that is, preventing undesired contact with the terminal by a technician.

In this disclosure, "finger-proof" means a configuration that meets the standard set forth in IEC <NUM> entitled "Degrees of Protection Provided by Enclosures" and code IP2XB relating to finger Ingress Protection. The "test finger" is based upon a solid object <NUM> in diameter or more and up to <NUM> long being prevented from entering an enclosure. Furthermore, if a standard test finger <NUM> long and <NUM> in diameter enters the enclosure there will be adequate clearance from live parts, i.e., the terminal. In this manner, the disclosed finger-proof terminal cap <NUM> prevents a technician from inadvertently touching the terminal <NUM> with the terminal cap <NUM> in place, for example, during assembly and/or removal of the bus bar assembly <NUM> with respect to the cells <NUM>.

The terminal cap <NUM> includes a first notch <NUM>, and the shroud <NUM> includes a second notch <NUM>. The shroud <NUM> is retained to the terminal cap <NUM> in the assembled condition by a retention feature. In the example, a first attachment feature <NUM> on the terminal cap <NUM>, such as a protrusion cooperates with a finger-like second attachment feature <NUM> on the shroud <NUM>, as best shown in <FIG>. As the shroud <NUM> and end <NUM> are pushed into the gap <NUM> during assembly, the first and second notches <NUM>, <NUM> become nested with one another to enclose the terminal <NUM> and the end <NUM> and the finger begins to deflect outward as the finger slides over the protrusion.

Once the shroud <NUM> is fully seated with respect to the terminal cap <NUM>, the second attachment feature <NUM> removably engages and interlocks with the first attachment feature <NUM>. Engagement of the first and second attachment features <NUM>, <NUM> signifies that the desired mechanical and electrical engagement between the terminal <NUM> and the end <NUM> has been achieved, that is, the female terminal end <NUM> has engaged the opposing faces <NUM> of the male terminal <NUM> and are safely enclosed. Once coupled, the retention feature prevents inadvertent decoupling of the bus bar <NUM> from the terminal <NUM> until the fingers and depressed and the bus bar assembly <NUM> is pulled away from the terminal cap <NUM>.

In the example, the shroud <NUM> includes multiple shroud portions cooperating with one another to enclose the bus bar <NUM>, which enables the bus bar to be serviced and the shroud to be reused. Referring to <FIG>, <FIG> and <FIG>, the multiple shroud portions include first and second shroud portions <NUM>, <NUM> nested relative to one another in an overlapping relationship. The first shroud portion <NUM> includes a sleeve providing an opening at one end that receives an end of the second shroud portion <NUM>. Although retentions features may be used between the first and second shroud portions <NUM>, <NUM>, a retention feature is not necessarily needed as the shroud portions are held together by the first and second notches <NUM>, <NUM> when the bus bar assembly <NUM> is in the assembled condition with respect to the terminal caps <NUM>.

<FIG> illustrate one example variation of the terminal cap <NUM>' configuration. The configuration used in the battery module <NUM> may depend upon the particular connection <NUM>' and housing <NUM>' arrangement as well as the given terminal 14a'.

Another example bus bar assembly <NUM> is shown in <FIG>. Like numerals indicate like elements. <FIG> and <FIG> illustrate one example variation of the terminal cap <NUM> configuration secured using different housings <NUM>, <NUM>'. Similar to the first bus bar assembly <NUM>, the nonconductive terminal cap <NUM> at least partially surrounds the terminal <NUM>. There is a U-shaped perimeter wall <NUM> circumscribing at least a portion of the terminal <NUM> on three sides to provide the gap <NUM> exposing the terminal <NUM> to receive the end <NUM>.

The post <NUM> receives the terminal <NUM> interiorly of the perimeter wall <NUM>. The post <NUM> shields the terminal <NUM> from contact in a manner similar to that described above in relation to the first bus bar assembly <NUM>. Together the perimeter wall <NUM> and the post <NUM> cooperate to provide the gap <NUM> as "finger-proof," that is, preventing undesired contact with the terminal by a technician.

Rather than using notches like the first bus bar assembly <NUM>, the second bus bar assembly <NUM> is received interiorly of the perimeter wall <NUM> instead of in overlapping relationship. The shroud <NUM> is retained to the terminal cap <NUM> in the assembled condition by a retention feature. The first attachment feature on the terminal cap is not illustrated in the Figures, but is provided by a protrusion cooperates with a finger-like second attachment feature <NUM> on the shroud <NUM>, as best shown in <FIG> and <FIG>. As the shroud <NUM> and end <NUM> are pushed into the gap <NUM> during assembly, the end <NUM> and the finger begins to deflect outward as the finger slides over the protrusion.

Once the shroud <NUM> is fully seated with respect to the terminal cap <NUM>, the second attachment feature <NUM> removably engages and interlocks with the first attachment feature. Engagement of the first and second attachment features signifies that the desired mechanical and electrical engagement between the terminal <NUM> and the end <NUM> has been achieved, that is, the female terminal end <NUM> has engaged the opposing faces <NUM> of the male terminal <NUM> and are safely enclosed. Once coupled, the retention feature prevents inadvertent decoupling of the bus bar <NUM> from the terminal <NUM> until the fingers and depressed and the bus bar assembly <NUM> is pulled away from the terminal cap <NUM>.

The shroud <NUM> includes multiple shroud portions cooperating with one another to enclose the bus bar <NUM>, which enables the bus bar to be serviced and the shroud to be reused. The multiple shroud portions include first and second shroud portions <NUM>, <NUM> nested relative to one another in an overlapping relationship. In this example, the second shroud portion <NUM> is provided on each of opposing sides of the central first shroud portion <NUM>. The first shroud portion <NUM> is provided by cover <NUM> snap-fit to a base <NUM>. The first shroud portion <NUM> includes a sleeve providing an opening at one end that receives a respective end of the second shroud portion <NUM> using a snap-fit <NUM> when in the assembled condition. Snap-fits, which include a mating window <NUM> and a protrusion <NUM>, are used to connect the various shroud pieces.

The bus bar <NUM> includes a U-shaped portion <NUM> received in the first shroud portion <NUM> to provide a space between opposing ends <NUM> of the bus bar <NUM>. The space accommodates an obstruction <NUM> arranged between the terminals <NUM> to enable compact packaging of the battery module <NUM> with respect to other components.

In operation, during assembly of the battery module <NUM>, a nonconductive terminal cap <NUM> is provided over a conductive battery cell terminal <NUM>. The terminal caps <NUM> may be provided as loose pieces that are secured to the battery housing <NUM>, if desired, or they may be integrated into the housing. The terminal cap <NUM> at least partially surrounds the terminal <NUM>, which is a male terminal. The terminal cap <NUM> has a perimeter wall <NUM> configured to circumscribe at least a portion of the terminal <NUM>. The terminal <NUM> is arranged in a post <NUM> that shields the terminal <NUM>. The perimeter wall <NUM> and the post <NUM> cooperate to provide a finger-proof gap <NUM> that exposes the terminal <NUM>.

A bus bar assembly <NUM> is provided with a bus bar <NUM> having an end <NUM>, which is a female terminal. A nonconductive shroud <NUM> encloses the bus bar <NUM> with the end <NUM> exposed through the shroud <NUM>. The end <NUM> of the bus bar assembly <NUM> is pushed into the gap <NUM> and into engagement with the terminal <NUM> so that the shroud <NUM> mates to the terminal cap <NUM> to enclose the end <NUM>. During mating, a first attachment feature <NUM> on the terminal cap <NUM> interlocks with a second attachment feature <NUM> on the shroud <NUM>.

In this manner, the terminal cap can be secured battery cell about the terminal, rendering the terminal finger-safe. Thus, the battery module is finger-proof even with the bus bar assemblies disconnected, which allows for safe assembly and handling of the battery module during assembly and servicing of the battery module.

It should also be understood that although a particular component arrangement is disclosed in the illustrated embodiment, other arrangements will benefit herefrom. Although particular step sequences are shown, described, and claimed, it should be understood that steps may be performed in any order, separated or combined unless otherwise indicated and will still benefit from the present invention.

Claim 1:
A battery module (<NUM>) comprising:
a battery cell (<NUM>) having an electrically conductive first male terminal (<NUM>); and
a second battery cell (<NUM>) having an electrically conductive second male terminal (<NUM>); and
a bus bar assembly (<NUM>) comprising:
a respective nonconductive terminal cap (<NUM>) configured to at least partially surround each of the terminals (<NUM>), the terminal caps (<NUM>) each have a perimeter wall (<NUM>) configured to circumscribe at least a portion of the respective terminal (<NUM>) to provide a gap (<NUM>) exposing the terminal (<NUM>), the terminal caps (<NUM>) each include a first attachment feature (<NUM>);
a bus bar (<NUM>) having a first end (<NUM>) defining a female terminal mechanically and electrically engaging the first male terminal (<NUM>) and a second end defining a female terminal engaging the second male terminal (<NUM>) in an assembled condition; and
a nonconductive shroud (<NUM>) enclosing the bus bar (<NUM>) and including a second attachment feature (<NUM>) removably engaging the first attachment feature (<NUM>) in the assembled condition to secure the shroud (<NUM>) to the terminal caps (<NUM>), characterized in that the terminal caps (<NUM>) each have a post (<NUM>) that receives the respective terminal (<NUM>) and is arranged interiorly of the respective perimeter wall (<NUM>), the gap (<NUM>) is provided between each post (<NUM>) and the respective perimeter wall (<NUM>), wherein the terminals (<NUM>) each have a perimeter edge (<NUM>) bounding opposing faces (<NUM>) of the respective terminal (<NUM>), the posts (<NUM>) each receive the respective terminal (<NUM>) and surround the respective perimeter edge (<NUM>) but leave at least one of the respective faces (<NUM>) exposed, and
each of the perimeter walls (<NUM>) extends beyond the posts (<NUM>), the perimeter walls (<NUM>) and the posts (<NUM>) cooperate to provide the gaps (<NUM>) as finger-proof, and wherein the shroud (<NUM>) includes first and second shroud portions (<NUM>, <NUM>) nested relative to one another in an overlapping relationship.