Patent Description:
Prior high voltage terminal interfaces have included a ribbed contact surface to provide a concentrated contact point between the electrical terminals. In some applications, this contact surface is embossed into the terminal and abruptly rises into the path of the mating terminal as the connection system is being connected.

Contact buttons have been used in switching contact applications, such as relays or contactors that conduct high voltages and/or high currents. However, these contact buttons have not been used for sliding contact interfaces such as is common in pluggable, automotive electrical connectors.

Publications <CIT> discloses a connector according to the preamble of claim <NUM>, <CIT>, <CIT> and <CIT> are considered to be relevant to the present application.

The problem underlying the present application is solved by an electrical connector according to claim <NUM> and by a method of forming an electrical connector according to claim <NUM>. Preferred embodiments are the subject matter of the dependent claims.

According to one embodiment, an electrical connector comprises a first bus bar formed of parallel first and second layers of electrically conductive material mechanically and electrically joined, and a second bus bar, wherein ends of the first and second layers of the first bus bar are separated so that the second electrical bus bar may be received between them. The electrical connector further comprises a contact button having a first layer formed of a first electrically conductive material that is attached to the first bus bar or the second bus bar and having a second layer formed of a second electrically conductive material clad to the first layer. It also comprises a clamp assembly including a retaining band surrounding the first bus bar and the second bus bar having a spring configured to provide a contact force between the contact button and the first bus bar or the second bus bar when the second bus bar is disposed between the parallel first and second layers of the first bus bar.

According to another embodiment, a method of forming an electrical connector configured to interconnect a first bus bar and a second bus bar comprises providing the first bus bar which has parallel first and second layers of electrically conductive material mechanically and electrically joined to one another, and providing a second bus bar configured to be received between separated ends of the first and second layers of the first bus bar. A contact button having a first layer formed of a first electrically conductive material and a second layer formed of a second electrically conductive material clad to the first layer is attached to the first bus bar or the second bus bar. A clamp assembly including a retaining band is also attached to the first bus bar such that the clamp assembly surrounds the first bus bar and the second bus bar. The clamp assembly has a spring configured to provide a contact force between the contact button and the first bus bar or the second bus bar when the second bus bar is disposed between the parallel first and second layers of the first bus bar.

According to one or more aspects of the present disclosure, an electrical connector includes a contact button having a first layer formed of a first electrically conductive material that is attached to a first electrical bus bar and having a second layer formed of a second electrically conductive material clad to the first layer and a clamp assembly including a retaining band surrounding the contact button and the first electrical bus bar and having a spring configured to provide a contact force between the contact button and a second electrical bus bar when the second electrical bus bar is disposed between the contact button and the spring.

In one or more embodiments of the electrical connector according to any one of the previous paragraphs, an outer surface of the second layer defines a plurality of protrusions.

In one or more embodiments of the electrical connector according to any one of the previous paragraphs, the plurality of protrusions is in the form of a plurality of spherical sections.

In one or more embodiments of the electrical connector according to any one of the previous paragraphs, the contact button has a generally cylindrical shape.

In one or more embodiments of the electrical connector according to any one of the previous paragraphs, an edge of the second layer is chamfered.

In one or more embodiments of the electrical connector according to any one of the previous paragraphs, a circumferential edge of the second layer is chamfered.

In one or more embodiments of the electrical connector according to any one of the previous paragraphs, the second electrically conductive material is selected from a list consisting of fine silver, a silver-copper alloy, a silver-tin oxide composite material, a silver-carbon composite material, a silver-nickel composite, or a silver-cadmium oxide composite material.

In one or more embodiments of the electrical connector according to any one of the previous paragraphs, the electrical connector includes a plurality of contact buttons.

In one or more embodiments of the electrical connector according to any one of the previous paragraphs, the plurality of contact buttons is arranged in a triangular pattern.

In one or more embodiments of the electrical connector according to any one of the previous paragraphs, the first bus bar is formed of parallel first and second layers of electrically conductive material mechanically and electrically joined. Ends of the first and second layers of the first bus bar are separated so that the second electrical bus bar may be received between them.

In one or more embodiments of the electrical connector according to any one of the previous paragraphs, the first and second layers of the first bus bar are symmetrical about a joint between them.

According to one or more aspects of the present disclosure, a method of forming an electrical connector configured to interconnect two electrical bus bars includes the steps of attaching a contact button to a first electrical bus bar, the contact button having a first layer formed of a first electrically conductive material and a second layer formed of a second electrically conductive material clad to the first layer and attaching a clamp assembly including a retaining band to the first electrical bus bar such that the clamp assembly surrounds the contact button and the first electrical bus bar. The clamp assembly has a spring configured to provide a contact force between the contact button and a second electrical bus bar when a second electrical bus bar is disposed between the contact button and the spring.

In one or more embodiments of the method according to the previous paragraph, the contact button is attached to the first electrical bus bar by a process selected from brazing, soldering, resistance welding, laser welding, and spin welding.

In one or more embodiments of the method according to any one of the previous paragraphs, an outer surface of the second layer defines a plurality of protrusions.

In one or more embodiments of the method according to any one of the previous paragraphs, the plurality of protrusions is in the form of a plurality of spherical sections.

In one or more embodiments of the method according to any one of the previous paragraphs, the contact button has a generally cylindrical shape.

In one or more embodiments of the method according to any one of the previous paragraphs, an edge of the second layer is chamfered.

In one or more embodiments of the method according to any one of the previous paragraphs, a circumferential edge of the second layer is chamfered.

In one or more embodiments of the method according to any one of the previous paragraphs, the method further includes the step of attaching a plurality of contact buttons to the first electrical bus bar.

In one or more embodiments of the method according to any one of the previous paragraphs, the method further includes the step of arranging the plurality of contact buttons in a triangular pattern.

In one or more embodiments of the method according to any one of the previous paragraphs, the first bus bar is formed of parallel first and second layers of electrically conductive material mechanically and electrically joined. Ends of the first and second layers of the first bus bar are separated so that the second electrical bus bar may be received between them. The method further includes inserting the second electrical bus bar between the ends of the first and second layers of the first bus bar.

In one or more embodiments of the method according to any one of the previous paragraphs, the first and second layers of the first bus bar are symmetrical about a joint between them.

This disclosure is directed to an electrical connector suited for use in a high voltage application (e.g., over <NUM> volts) and particularly to an electrical connector having cladded electrical contact points. The current carried by such an electrical connector may typically range from <NUM> to <NUM> amperes.

An electrical connector configured to interconnect two or more electrical bus bars or flat blade terminals and suited for use in high voltage applications is presented herein.

As shown, in <FIG>, the electrical connector <NUM> includes a contact button <NUM> that is attached to a first electrical bus bar <NUM> formed of an electrically conductive material, such as a copper-based or aluminum-based material. The contact button <NUM> may be attached to the first bus bar <NUM> by brazing, soldering, resistance welding, laser welding, spin welding or any other suitable process. The contact button <NUM> has a bottom layer <NUM> that is attached directly to the first bus bar <NUM>. As illustrated in <FIG>, this bottom layer <NUM> is formed of a first electrically conductive material, such as copper or aluminum. The bottom layer <NUM> may also include a flux material applied over the surface that is to be attached to the first bus bar <NUM> when using a brazing or welding process. The contact button <NUM> also has a top layer <NUM> that is formed of a second electrically conductive material and is clad to the bottom layer <NUM>. As illustrated in <FIG>, the contact button <NUM> may also have another intermediate layer <NUM> between the bottom and top layers <NUM>, <NUM> that is formed of a third electrically conductive material, e.g., a nickel-based alloy, a steel alloy, a MONEL® alloy, or a nickel-plated steel alloy. When the contact button <NUM> includes this intermediate layer <NUM>, the bottom and top layers <NUM>, <NUM> are clad to the intermediate layer <NUM>. The second electrically conductive material is typically different from the first electrically conductive material and preferably has a lower electrical resistance than the first electrically conductive material. The second electrically conductive material may be a fine silver, i.e., a silver alloy having <NUM>% by weight, a silver-copper alloy, a silver-tin oxide composite material, a silver-carbon composite material , a silver-nickel composite, or a silver-cadmium oxide composite material. Contact buttons of this type are available from Umicore Electrical Material USA Inc. of Glen Falls, New York. As shown in <FIG> and <FIG>, the first bus bar <NUM> may include a countersunk area <NUM> or a similar feature to help locate the contact button <NUM> on the first bus bar <NUM>.

The electrical connector <NUM> also includes a clamp assembly <NUM> having a retaining band <NUM> that surrounds the contact button <NUM> and the first bus bar <NUM>. The clamp assembly <NUM> also has a spring <NUM> that is configured to provide a contact force between the contact button <NUM> and a second electrical bus bar <NUM> or male blade terminal, shown in <FIG>, when the second bus bar <NUM> or terminal is disposed between the contact button <NUM> and the spring <NUM>, as shown in <FIG>. Returning to <FIG>, the spring <NUM> is a cantilevered plate having an arcuate shape that is integrally formed with the retaining band <NUM>. The clamp assembly <NUM> may be formed of a stainless-steel alloy, such as SAE <NUM>½ hard stainless-steel. In alternative embodiments, other spring shapes or materials may be employed to provide the clamping force. It is appreciated that in an alternative embodiment the contact button <NUM> could be attached to the second electrical bus bar <NUM>.

The contact button <NUM> has a generally flat cylindrical shape and the outer edges of the top layer <NUM> are chamfered as can be seen in <FIG>, preferably by a coining process, in order to reduce edges that could increase the mating force when the second bus bar <NUM> is placed between the spring <NUM> and the contact button <NUM>.

The alloy forming the top layer <NUM> is selected to withstand at least fifty or more mating/unmating cycles between the first and second bus bars <NUM>, <NUM>. Because the top layer <NUM> is clad to the contact button <NUM>, the thickness of the top layer <NUM> can be made thicker more economically than providing a plated layer of similar thickness on the contact surface of a bus bar. A silver-graphene alloy or other silver-carbon composites having graphene, graphite, or other small carbon particles may be deposited on a surface of the contact button <NUM> to further increase durability of the electrical connector, thereby providing an increased number of successful mating/unmating cycles.

As illustrated in <FIG>, alternative embodiments of the contact button <NUM> may include a number of contact protrusions in the form of spherical bumps <NUM>. The bumps <NUM> provide smaller, more precise geometry than can be formed in thicker bus bars or terminals. This allows for more points of contact in a given area which makes for a more robust interface in a single contact button.

In an alternative embodiment shown in <FIG>, a number of separate contacts buttons <NUM> may be arranged and attached to the first bus bar <NUM> in order to provide more points of contact in a given area. The contact buttons <NUM> may be arranged in a triangular shape to minimize the contact force needed to mate the second bus bar <NUM> with the electrical connector <NUM>. The first bus bar <NUM> may also include an insulation layer <NUM> surrounding a portion of the first bus bar <NUM>.

In a different alternative embodiment shown in <FIG>, the electrical connector <NUM> includes a first bus bar <NUM> that is formed of parallel first and second layers <NUM>, <NUM> of electrically conductive material. The first and second layers <NUM>, <NUM> are mechanically and electrically joined, for example by welding, riveting, use of a clinch pin, etc. Ends of the first and second layers <NUM>, <NUM> are separated so that a second electrical bus bar <NUM> may be received between them. A contact button <NUM> is attached to the second first bus bar <NUM>. The electrical connector <NUM> also includes a clamp assembly <NUM> having a retaining band <NUM> that surrounds the contact buttons <NUM> on the second bus bar <NUM> and the first bus bar <NUM>. The clamp assembly <NUM> also has a spring <NUM> that is configured to provide a contact force between the contact button <NUM> on the second electrical bus bar <NUM> and the first bus bar <NUM> by pressing against the first bus bar <NUM> which then presses the contact button <NUM> against the second bus bar <NUM>.

Another alternative embodiment of an electrical connector <NUM> is shown in <FIG>. The electrical connector <NUM> is similar to the electrical connector <NUM> shown in <FIG>, with a primary difference being the contact button <NUM> is attached to the second electrical bus bar <NUM> rather than to the second layer <NUM> of the first bus bar <NUM>. The electrical connector <NUM> also includes a clamp assembly <NUM> having a retaining band <NUM> that surrounds the contact buttons <NUM> and the first bus bar <NUM>. The clamp assembly <NUM> also has a spring <NUM> that is configured to provide a contact force between the contact button <NUM> on the second bus bar <NUM> and the first bus bar <NUM>.

Yet another alternative embodiment of an electrical connector <NUM> is shown in <FIG>. The electrical connector <NUM> is similar to the electrical connector <NUM> shown in <FIG>, with a primary difference being the parallel first and second layers <NUM>, <NUM> of the first bus bar <NUM> have the same thickness and are symmetrically arranged in relation to a joint <NUM> between them. Contact buttons <NUM> are attached to the upper and lower surfaces the second bus bar <NUM>. The electrical connector <NUM> also includes a clamp assembly <NUM> having a retaining band <NUM> that surrounds the contact button <NUM> and the first bus bar <NUM>. The clamp assembly <NUM> also has a spring <NUM> that is configured to provide a contact force between the contact button <NUM> on the first bus bar <NUM> and the second bus bar <NUM> by pressing against the first bus bar <NUM> which then presses the contact button <NUM> against the second bus bar <NUM>.

<FIG> shows a flow chart of a method <NUM> of forming an electrical connector configured to interconnect two electrical bus bars. The method includes the following steps:.

While this invention has been described in terms of the preferred embodiments thereof, it is not intended to be so limited, but rather only to the extent set forth in the claims that follow. For example, the above-described embodiments (and/or aspects thereof) may be used in combination with each other. In addition, many modifications may be made to configure a particular situation or material to the teachings of the invention without departing from its scope. Dimensions, types of materials, orientations of the various components, and the number and positions of the various components described herein are intended to define parameters of certain embodiments and are by no means limiting and are merely prototypical embodiments. The scope of the invention should, therefore, be determined with reference to the following claims.

As used herein, 'one or more' includes a function being performed by one element, a function being performed by more than one element, e.g., in a distributed fashion, several functions being performed by one element, several functions being performed by several elements, or any combination of the above.

It will also be understood that, although the terms first, second, etc. are, in some instances, used herein to describe various elements, these elements should not be limited by these terms. For example, a first contact could be termed a second contact, and, similarly, a second contact could be termed a first contact, without departing from the scope of the various described embodiments. The first contact and the second contact are both contacts, but they are not the same contact.

The terminology used in the description of the various described embodiments herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used in the description of the various described embodiments and the appended claims, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will also be understood that the term "and/or" as used herein refers to and encompasses all possible combinations of one or more of the associated listed items. It will be further understood that the terms "includes," "including," "comprises," and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

As used herein, the term "if' is, optionally, construed to mean "when" or "upon" or "in response to determining" or "in response to detecting," depending on the context. Similarly, the phrase "if it is determined" or "if [a stated condition or event] is detected" is, optionally, construed to mean "upon determining" or "in response to determining" or "upon detecting [the stated condition or event]" or "in response to detecting [the stated condition or event]," depending on the context.

Claim 1:
An electrical connector (<NUM>, <NUM>, <NUM>), comprising:
a first bus bar (<NUM>, <NUM>, <NUM>) formed of parallel first and second layers (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) of electrically conductive material mechanically and electrically joined;
a second bus bar (<NUM>, <NUM>, <NUM>), wherein ends of the first and second layers (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) of the first bus bar (<NUM>, <NUM>, <NUM>) are separated so that the second electrical bus bar (<NUM>, <NUM>, <NUM>) may be received between them;
the connector being characterized by:
a contact button (<NUM>, <NUM>, <NUM>) having a first layer formed of a first electrically conductive material that is attached to the first bus bar (<NUM>) or the second bus bar (<NUM>, <NUM>) and having a second layer formed of a second electrically conductive material clad to the first layer; and
a clamp assembly (<NUM>, <NUM>, <NUM>) including a retaining band (<NUM>, <NUM>, <NUM>) surrounding the first bus bar (<NUM>, <NUM>, <NUM>) and the second bus bar (<NUM>, <NUM>, <NUM>) having a spring (<NUM>, <NUM>, <NUM>) configured to provide a contact force between the contact button (<NUM>, <NUM>, <NUM>) and the first bus bar (<NUM>, <NUM>) or the second bus bar (<NUM>) when the second bus bar (<NUM>, <NUM>, <NUM>) is disposed between the parallel first and second layers (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) of the first bus bar (<NUM>, <NUM>, <NUM>).