Patent Description:
The connection points between electric terminals in some applications play an important role in ensuring a high reliability and efficiency of an electrical system.

For example, inside a vehicle it is essential to ensure the mechanical stability of the electrical joints, to avoid accidental disconnections due to vibrations.

The quality of the electrical contact is also important, and in particular that the contact resistance is minimized. In fact, where operating currents are particularly high, even a small voltage drop due to the electrical resistance of a junction can cause a significant loss of efficiency, as well as a dangerous localized heating.

Accordingly, connections between battery cells within a battery module for applications in electric or hybrid vehicles are particularly sensitive.

In the sector, the term battery pack refers to the entire main assembly of accumulation elements present in the vehicle. The battery pack contains one or more pre-assembled battery modules, which can be connected to each other in series or in parallel. Each battery module in turn encloses a plurality of battery cells.

The cell is a single block formed by those elements which are indispensable for the development of electrochemical reactions which allow the accumulation of energy. Such elements include two electrodes, i.e., the anode and the cathode of the cell, respectively, an interface electrolyte between the electrodes, a casing containing the electrodes and the electrolyte, and electric terminals which are connected to the electrodes and partially emerge outside the casing.

Depending on the arrangement of the components of a cell, and in particular the shape of the casing, different types of battery cells are distinguished, including pouch cells, prismatic cells and cylindrical cells.

Each cell offers a rather low electrical potential, so inside a battery module the cells are connected mainly in series, without necessarily excluding parallel connections. In a series connection, the positive terminal of a cell must be connected to the negative terminal of the adjacent cell. Parallel connections can involve multiple terminals of the same or different polarities.

The terminals of the battery cells can be made in various forms. One example is screw terminals, i.e., terminals with a threaded conductive stem emerging outside the casing. A known example of a screw terminal connection is a lamina busbar with two holes. The two screw terminals to be connected each extend through a respective busbar hole, perpendicular to the lamina of the busbar. A nut is tightened against the busbar by virtue of the thread of the screw terminal, ensuring the electrical connection.

Another example is tab terminals, i.e., conductive lamina with a surface extension which prevails to the thickness. Couples of tab terminals are usually welded together, directly, or are welded to a common busbar which acts as a spacer between the two terminals.

A direct welding between two tab terminals can be accomplished by crimping, i.e., a complementary mechanical deformation whereby a portion of one tab permanently penetrates into a recess of the other. An example instead of welding to a busbar is laser welding, which involves localized heating, with partial fusion of the contact surfaces between busbar and tab.

The described solutions are defective in some respects related to reliability and contact resistance. For example, in the case of screw terminals a significant portion of current must pass from the screw to the nut and from the nut to the busbar, with two physical separations, with a limited surface, which cause an increase in resistance. Furthermore, continuous vibrations cam loosen the contact and further increase the resistance.

Crimping does not ensure good contact quality for the entire potentially available surface of the tab terminal, and it also suffers from vibration.

Laser welding creates a relatively low resistance connection, but only at the welding areas reached by the laser, and not for the entire surface of the tab. Furthermore, the connection is good and is mechanically stable only as long as the localized fusion allows a good alloy to be formed between the material of the tab and of the busbar.

This condition does not occur in all battery cells. This is due to the fact that the positive and negative terminals, as well as the busbar, in order to obtain high performance, are usually formed with different metals, with low impurities. Therefore, they have different melting points, which complicate, at the level of the production process, the formation of an alloy of the desired quality. The presence of impurities also hinders the formation of a good alloy.

A further problem is related to the irreversibility of the connections between the described tab terminals, which hinders subsequent maintenance. <CIT>, <CIT>, <CIT> and <CIT> are examples of the prior art.

The object of the present invention is to allow a mechanically stable and low-resistance connection between tab electric terminals, particularly battery cell terminals.

It is also an object of the invention to reversibly couple tab terminals to each other.

This and other objects are achieved by a coupling device for coupling tab electric terminals, and by a battery module, according to any of the appended claims.

In particular, the coupling device includes two jaws, facing each other, between which the tab terminals to be connected are arranged. The two jaws are clamped together in a first direction, although the contact surfaces of the tab terminals are facing each other in another, second direction, transverse to the first one.

One or more wedge surfaces are included in the area between the two jaw bases. Wedge surfaces can for example be formed in side arms of U- or L-shaped jaws. Alternatively, the wedge surfaces can be part of other components which are compressed by the jaws in the first direction. In any case, the wedge surfaces are arranged so as to convert the pressure in the first direction, developed by the jaws, into a pressure in the second direction.

By virtue of this second pressure, the contact surfaces of the tab terminals can be pressed against each other, directly or with the interposition of a busbar which acts as a spacer. Alternatively, the pressure in the second direction can also be in a direction for mutually distancing the tab terminals. This pressure can also favour electrical contact, for example when complementary wedge surfaces are formed in two pieces of the busbar. Therefore, the displacement pressure results in appropriate contact pressures between each tab terminal and the various parts of the busbar. Excessive displacements with loss of contact are prevented by side elements such as jaw arms.

The pressure in the second direction causes the electrical contact to exploit the entire available surface of the tab terminal. Furthermore, even in the event of strong vibrations tending to detach the various electrical contact surfaces, the elasticity of the system and the operating principle of the clamped wedge surfaces immediately recreates the desired contact pressure, ensuring stability.

Further features and advantages of the invention will be recognized by those skilled in the art from the following detailed description of exemplary embodiments of the invention.

The accompanying figures schematically show, by way of non-limiting example, useful examples for understanding some embodiments of the invention, and in particular:.

The different embodiments illustrated in the figures contain variants of a coupling device for coupling two or more tab electric terminals. A number of aspects of the invention are common to all of these embodiments.

In summary, some of the aspects common to the various embodiments, which are further explored below, are given by the fact that the device comprises a pair of jaws spaced apart from each other in a first direction, each jaw having a base. The bases of the jaws delimit in the first direction a seat therebetween, the seat being adapted to receive therein two or more tab electric terminals, so that respective electrical contact surfaces of the terminals face each other in a second direction, transverse to the first direction. Side elements of the device are spaced apart from each other in the second direction, and are positioned so as to delimit the seat in the second direction and retain the terminals therebetween. A clamping element of the device is configured to clamp the jaws towards each other in the first direction. At least one wedge surface of the device is inclined with respect to the first and second directions, and is formed, with respect to the first direction, between the jaw bases. The wedge surface is arranged so as to convert a pressure in the first direction, exerted by clamping the pair of jaws, into a pressure in the second direction on the terminals, when present in the seat.

In addition to the common aspects, the features which will be described with reference to a specification of the illustrated embodiments, except for obvious technical incompatibilities or explicit indications to the contrary, shall be understood as interchangeable, or applicable to any of the other embodiments.

In greater detail, a battery module is indicated as a whole with the reference numeral <NUM>.

The battery module <NUM> comprises a casing (not shown).

The module <NUM> also comprises a plurality of battery cells <NUM>, contained in the casing. The preferred cells <NUM> are pouch-type cells.

Each cell <NUM> comprises a pair of tab electric terminals <NUM>, preferably spaced apart in a first direction X-X.

The tab terminals <NUM> are made in the form of a lamina, preferably planar, perpendicular to a second direction Y-Y. The second direction Y-Y is transverse, preferably perpendicular, to the first direction.

Each terminal <NUM> has two opposite faces.

The cells <NUM> are arranged such that pairs of tab terminals <NUM> of different cells <NUM> are aligned with each other in the second direction Y-Y and have respective contact surfaces <NUM> facing each other in the second direction Y-Y. The cells <NUM> in particular are aligned in the second direction X-X.

Each contact surface <NUM> identifies one of the faces of the terminal <NUM>. As will be detailed below, the contact surfaces <NUM> of a pair of terminals <NUM> to be connected can face, and be in contact, with each other, or face, and be spaced apart from, each other.

Each cell <NUM> further comprises its own casing <NUM>, and the terminals <NUM> protrude from the casing <NUM> of the cell <NUM>.

As is known, each battery cell <NUM> then comprises electrodes (not shown), inside the casing and electrically connected to the terminals <NUM>, and an electrolyte (not shown) inside the casing and interposed between the electrodes.

The battery module <NUM> comprises at least one coupling device <NUM>, preferably a plurality of coupling devices <NUM> for two or more tab electric terminals <NUM> of the battery cells <NUM>. For example, a single pair of terminals <NUM>, or a group of terminals <NUM> consisting of more than two terminals <NUM>, can be connected.

Those skilled in the art will understand that the coupling device <NUM> can also be provided separately from the battery module <NUM>, and can also be used to connect tab electric terminals <NUM> of other types of devices without correlation with the battery sector.

The coupling device <NUM> is aimed at the mechanical coupling of the terminals <NUM>, so that they are in electrical contact with each other.

The coupling device <NUM> can also directly perform electrical coupling functions between the terminals <NUM>, in preferred embodiments to be illustrated, in which the terminals <NUM> are not in direct contact with each other, but with the interposition of some conductive elements of the coupling device <NUM>.

The device <NUM> comprises a pair of jaws <NUM>, spaced from each other in the first direction X-X. As will be seen below, the jaws <NUM> are connected to each other at least indirectly, with the possibility of some mutual movements.

Each jaw <NUM> has a base <NUM>. The bases <NUM> of the jaws <NUM> are spaced apart and face each other in the first direction X-X. Each base <NUM> is also arranged transverse to the first direction X-X.

Thus the jaws <NUM> delimit a seat, formed between the jaws <NUM>. In detail, the seat is delimited in the first direction X-X by the bases <NUM> of the jaws <NUM>.

The device <NUM> further comprises side elements <NUM>, spaced apart from each other in the second direction Y-Y. The side elements <NUM> are positioned so as to delimit the seat in the second direction Y-Y.

The side elements <NUM> can be integrally formed with at least one of the jaws <NUM>, or they can be connected directly or indirectly to the jaws <NUM>. Thus the side elements <NUM> are connected at least indirectly also to each other. In some embodiments, a certain degree of movement of the side elements <NUM> with respect to each other is allowed.

In the preferred embodiments, each side element <NUM> is identified by an arm of one of the jaws <NUM>. Therefore, the side elements <NUM> are integrally formed with the jaws <NUM>. Precisely, each jaw <NUM> has at least one arm, preferably two arms, connected to respective opposite end portions of the base <NUM> of the jaw <NUM>.

Given the identity, at least in some embodiments, between the arms of the jaws <NUM> and the side elements <NUM>, the arms can also be indicated below with the reference numeral <NUM>.

The arms of each jaw <NUM> extend at least in part in the first direction X-X from the respective base <NUM> towards the opposite jaw <NUM>. Preferably, each arm <NUM> mainly extends in a direction which forms an angle with the first direction X-X not exceeding <NUM>°.

In the case of a single arm per jaw <NUM>, the jaw <NUM> can be L-shaped. In the case of a pair of arms per jaw <NUM>, the jaw <NUM> can be U-shaped, with the two arms of each jaw <NUM> spaced apart in the second direction Y-Y.

In order for the seat to be delimited in the second direction Y-Y on both sides, it is possible for example that both jaws <NUM> are U-shaped, or both are L-shaped, with the single arm of each jaw <NUM> spaced in the second direction Y-Y from the arm of the opposite jaw <NUM>.

Mixed configurations are also conceivable, in which one of the side elements <NUM>, on one side of the seat, is represented by an arm of an L-shaped jaw <NUM>, while the side element <NUM> on the opposite side of the seat is a member independent of the jaws <NUM>, or in which both side elements are arms of a single U-shaped jaw <NUM>, while the other jaw <NUM> lacks arms.

The seat is shaped to receive two or more tab electric terminals <NUM> to be connected therein. In particular, the terminals <NUM> are insertable in the seat along a direction perpendicular to the first direction X-X and the second direction Y-Y. The connection of the side elements <NUM> is such that they are able to retain the terminals <NUM> in the seat between each other.

In an assembled condition, each terminal <NUM> has at least one face, which identifies a contact surface <NUM>, oriented toward another terminal <NUM>. Face <NUM>, which is opposite the commented contact surface <NUM>, can in turn be a contact surface <NUM>, oriented toward yet another terminal <NUM>, or can be oriented toward at least one of the side elements <NUM> delimiting the seat.

In preferred embodiments, the coupling device <NUM> comprises at least one spacing block <NUM>, or busbar, made of an electrically conductive material. A single spacing block <NUM> is sufficient if there are two terminals <NUM> to be connected, while for a greater number of terminals <NUM> more spacing blocks <NUM> are preferable.

Each spacing block <NUM> is arranged in the seat between the jaws <NUM>. The spacing block <NUM> has two opposite abutment surfaces <NUM>. The abutment surfaces <NUM> are transverse to the second direction Y-Y and are spaced apart from each other in the second direction Y-Y.

The spacing blocks <NUM> divide the seat into compartments, for example two compartments, each intended to receive a respective terminal <NUM>. The compartments are spaced apart from each other in the second direction Y-Y. The abutment surfaces <NUM> of each spacing block <NUM> each face a different compartment.

In an assembled condition, i.e., when the terminals <NUM> are inserted in the seat and are coupled to each other by the device <NUM>, the abutment surfaces <NUM> of each spacing block <NUM> each face, and is in contact with, the contact surface <NUM> of a respective terminal <NUM>.

Alternatively, the contact surfaces <NUM> of the terminals <NUM> in the seat can be in direct contact with each other, without any spacing block <NUM> being included.

If present, each spacing block <NUM> preferably also has opposite secondary surfaces <NUM>. The secondary surfaces <NUM> are transverse to the first direction X-X and spaced from each other in the first direction X-X. The secondary surfaces <NUM> each face the base <NUM> of a respective jaw <NUM>, optionally in mutual contact.

The jaws <NUM> are movable with respect to one another in the first direction X-X. In fact, the device <NUM> comprises at least one clamping element <NUM> configured to clamp the jaws <NUM> towards one another in the first direction X-X.

Preferably, the jaws <NUM> are connected to each other by means of the clamping element <NUM>. In detail, the clamping element <NUM> comprises a stem <NUM> extending along the first direction X-X.

In the illustrated embodiment, the stem <NUM> is at least partly threaded, and is part of a screw which also comprises a head <NUM>.

The clamping element <NUM> can also comprise a threaded element, for example a nut <NUM>, screwable on the stem <NUM> to clamp the jaws <NUM> together. The jaws <NUM> are interposed between the head <NUM> of the screw and the nut <NUM>, so as to be clampable therebetween. As an alternative to the nut <NUM>, a clamping hole <NUM> of at least one jaw <NUM>, discussed below, can be threaded to allow the clamping. In yet another variation, the threaded stem <NUM> can be headless, while the head <NUM> can be replaced by a further nut <NUM> or other threaded element, so as to have, for example, two nuts <NUM> clamped at the two end portions of the stem <NUM>.

Finally, pairs of washers <NUM> fitted on the stem on opposite sides of the device <NUM> are illustrated, although in principle a single washer <NUM>, or washers <NUM> on a single side, can be included. Preferably, each washer <NUM> is a conical washer, i.e., a cup spring. Each washer <NUM> is placed between a jaw <NUM> and a part of the clamping element <NUM>, such as the head <NUM> of the screw or a nut <NUM>. The concavity of the conical washer <NUM> faces the jaw <NUM>.

The washers <NUM> can represent a preferred embodiment of an elastic element, such as to ensure a limited clearance of movement of the jaws <NUM> with respect to the screw and the nut <NUM>, even when clamped. This makes the electrical connection more stable even in case of vibrations.

Further elasticity can be conferred on the device by an appropriate design of the jaws <NUM>. In particular, the jaws <NUM> are preferably made of a metal with elastic features, such as steel. Moreover, the thickness of the bases <NUM> in the first direction X-X is selected so as to ensure the desired elastic reaction force to compensate for the vibrations.

In the illustrated embodiments, each jaw <NUM> comprises a clamping hole <NUM>, crossed by the stem <NUM>. The clamping hole <NUM> is preferably formed in the base <NUM> of the respective jaw <NUM>.

Preferably, also the spacing block <NUM> is connected to the jaws <NUM> by the clamping element <NUM>.

In detail, the spacing block <NUM> has a clamping hole <NUM>. The stem <NUM> of the clamping element <NUM> also extends through the clamping hole <NUM> of the spacing block <NUM>, as well as through the clamping holes <NUM> of the jaws <NUM>.

In the embodiment of <FIG>, the spacing block <NUM> has also at least one connection hole <NUM>, preferably independent of the possible clamping hole <NUM>.

The connection hole <NUM> is configured for the electrical connection with a male connector <NUM> of at least one external electrical device (not shown).

The connection with external devices allows for example the measurement of voltage or temperature, which are shared between the spacing block <NUM> and the tab terminals <NUM>, or the exchange of current.

However, the connection hole <NUM> is only an embodiment example of a possible connection element, for the electrical connection with the external electrical device. For example, the spacing block <NUM> can include a faston terminal.

It is preferred that the connection elements are formed in the spacing block <NUM>, since this shares the temperature and the electrical potential with the terminals <NUM>. However, connection elements can also be formed in other components of the device <NUM>, such as the jaws <NUM>, if they are made of electrically and/or thermally conductive materials.

According to the invention, at least one wedge surface <NUM> is present in the coupling device <NUM>.

Each wedge surface <NUM> can be formed in a special wedge element, or in other elements of the coupling device <NUM>, for example in one or more of the jaws <NUM>, or in the spacing block <NUM>.

Each wedge surface <NUM> is positioned, considering the first direction X-X, between the positions in the first direction X-X of the bases <NUM> of the two jaws <NUM>. In more detail, each wedge surface <NUM> can be inside the seat between the jaws <NUM>, or it can be part of one of the elements delimiting the seat, such as the side elements <NUM>, for example given by the arms of the jaws <NUM>.

Although it is possible to obtain coupling devices <NUM> according to the invention with a single wedge surface <NUM>, including more than one wedge surface <NUM>, for example two or four suitably arranged wedge surfaces <NUM>, allows a better and more symmetrical distribution of the forces in the coupling device, as will be evident from the following. A greater number of wedge surfaces <NUM> is particularly preferable if the connection of numerous terminals <NUM> with a single device <NUM> is required.

Various aspects of one wedge surface <NUM> will therefore be described, which are in any case to be understood as applicable to each thereof.

The wedge surface <NUM> is inclined with respect to the first and second directions X-X, Y-Y.

The wedge surface <NUM> is arranged so as to convert a pressure in the first direction X-X, exerted by clamping the pair of jaws <NUM>, into a pressure in the second direction Y-Y.

Those skilled in the art will understand how different inclinations of the wedge surface <NUM> with respect to the first and second directions X-X, Y-Y allow to adjust a ratio between the pressures in the first and second direction Y-Y to the desired value, in the various embodiments described below.

The wedge surface <NUM> is translatable in the first direction X-X together with the jaws <NUM>.

This applies either in the case of wedge surfaces <NUM> made in the jaws <NUM> themselves, or in the case of wedge elements fixed to the jaws <NUM>, or positioned in the seat so as to be pressed in the first direction X-X by at least one jaw <NUM> during the clamping of the jaws <NUM>.

The pressure in the second direction Y-Y is present at least in the assembled condition, i.e., when the terminals <NUM> are present in the seat. Such a pressure in the second direction Y-Y acts right on the terminals <NUM>, directly or indirectly.

In particular, the pressure in the second direction Y-Y is transmitted at least on the contact surfaces <NUM> of each terminal <NUM>. This can be a pressure of direct contact between the contact surfaces between the two terminals <NUM>. Alternatively, when a spacing block <NUM> is included, the pressure in the second direction Y-Y can be a contact pressure between each abutment surface <NUM> of the spacing block <NUM> and the contact surface <NUM> of a relative terminal <NUM>.

Concurrently with this pressure between the contact surfaces <NUM>, or between them and the abutment surfaces <NUM>, a pressure in the second direction Y-Y between the terminals <NUM> and the side elements <NUM> is also preferably provided, as will be discussed.

In order to convert the pressure from the first to the second direction X-X, Y-Y, each wedge surface <NUM> is in contact with a respective receiving surface.

In some embodiments, the receiving surface is another of the wedge surfaces <NUM>, complementary to that considered.

In other embodiments, the receiving surface may not be wedge shaped, but include for example an edge on which the wedge surface <NUM> acts.

For example, the receiving surface can be an edge of one of the terminals <NUM>.

<FIG> and <FIG> show details of a first embodiment of the invention, when designed for the connection of a single pair of terminals <NUM>.

In accordance therewith, each wedge surface <NUM> is formed in a respective arm of a respective jaw <NUM>, or in one of the side elements <NUM>, as particularly visible in <FIG>. More precisely, both jaws are U-shaped. Furthermore, each arm of each jaw <NUM> has a wedge surface <NUM>.

In such an example, the receiving surface, relating to each wedge surface <NUM>, is given by at least one part of that face <NUM>, of a respective terminal <NUM>, which is opposite the contact surface <NUM>. Precisely, the receiving surface is given by an edge of the face <NUM>.

By virtue of this arrangement, each terminal <NUM> is compressed between two wedge surfaces <NUM> of two distinct jaws <NUM>, which act at opposite edges of the face <NUM> of the terminal <NUM> opposite the contact surface <NUM>. Accordingly, each terminal <NUM> translates in the second direction Y-Y toward the opposite terminal <NUM>, until reaching the desired compression condition in the second direction Y-Y.

It should be noted that in this embodiment the pressure in the second direction Y-Y is a pressure for mutual approach of the terminals <NUM>. Pressures of mutual approach can also be obtained with alternative arrangements of the wedge surfaces <NUM>, not necessarily formed directly in the jaws <NUM>.

In general, however, they are obtained when at least one of the terminals <NUM> is interposed, considering the second direction Y-Y, between a wedge surface <NUM> and the opposite terminal <NUM>. More in detail, at least one wedge surface <NUM> is arranged on a first side of the seat. All the electric terminals <NUM> present in the seat <NUM> are between such at least one wedge surface <NUM> and an opposite side element <NUM>, which is on a second side of the seat, opposite the first side.

It should be noted that in these conditions each wedge surface <NUM> faces the interior of the seat.

The embodiment of <FIG> and <FIG> includes a spacing block <NUM>. Therefore, the pressure for approaching the terminals <NUM> results in a pressure between the contact surfaces <NUM> of the terminals <NUM> and the respective abutment surfaces <NUM> of the spacing block <NUM>, and also between the side elements <NUM> and the terminals <NUM>.

In detail, when the terminals <NUM> are removed from the seat, each wedge surface <NUM> faces directly a respective abutment surface <NUM> of the spacing block <NUM> in the second direction Y-Y.

However, the arrangement of the wedge surfaces <NUM> of <FIG> is also suitable for the case in which there is no spacing block <NUM>, with obvious dimensional adaptations to reduce the size of the seat. The pressure for approaching the terminals <NUM> results in such a case into a pressure of direct contact between the contact surfaces <NUM> of the terminals <NUM>.

One of the possible asymmetric variants of this embodiment can provide for example that on one side of the seat there are one or two side elements <NUM> each represented by an arm of a jaw <NUM>, with a wedge surface <NUM>, while on the opposite side of the seat the side element <NUM> is distinguished from the jaws <NUM> and is simply kept in a fixed position, free of wedge surfaces <NUM>.

A second embodiment of the invention is shown in <FIG>. It envisages that the spacing block <NUM> comprises two distinct and cooperating spacing bodies <NUM>.

Each spacing body <NUM> has one of the two abutment surfaces <NUM> of the spacing block <NUM>. Furthermore, each spacing body <NUM> has one of the two secondary surfaces <NUM> of the spacing block <NUM>. In addition, each spacing body <NUM> has its own wedge surface <NUM>. The wedge surfaces <NUM> of the two spacing bodies <NUM> are complementary and cooperating with each other, i.e., one acts as a receiving surface for the other.

Essentially, the two spacing bodies <NUM> are obtainable by dividing the spacing block <NUM> into two parts, along an ideal diagonal surface of the spacing block <NUM>, which originates the two wedge surfaces <NUM>.

The secondary surface <NUM> of each spacing body <NUM> is in contact with the base <NUM> of a respective jaw <NUM>. Thus, during the clamping of the jaws <NUM>, each jaw <NUM> presses the secondary surface <NUM> of one of the spacing bodies <NUM> in the first direction X-X. Therefore, the joint translation in the first direction X-X of the spacing bodies <NUM> together with the respective jaws <NUM> is achieved.

During this translation in the first direction X-X, the wedge surfaces <NUM> of the two spacing bodies <NUM> are pressed against each other, so as to slide on each other. In fact, each spacing body <NUM> is compressed between one of the jaws <NUM> and the opposite spacing body <NUM>.

Due to this mutual sliding of the wedge surfaces <NUM>, the translation of each spacing body <NUM> in the first direction X-X, together with the respective jaw <NUM>, is concomitant with a translation of the spacing body <NUM> in the second direction Y-Y with respect to the respective jaw <NUM>. In other words, there is also a sliding in the second direction Y-Y of the secondary surface <NUM> of the spacing body <NUM> along the base <NUM> of the jaw <NUM>.

As can be seen in <FIG>, the base <NUM> of each jaw <NUM> can have protrusions <NUM>, placed on the sides of each spacing body <NUM>. The protrusions <NUM> limit the movement of the spacing bodies <NUM> in the second direction Y-Y.

It should also be noted that, if the stem <NUM> of the clamping element <NUM> passes through a clamping hole <NUM> of the spacing block <NUM>, such a clamping hole <NUM> can extend through both spacing bodies <NUM>. Similarly, each spacing body <NUM> can have its own connection hole <NUM>.

In view of the necessity of the spacing bodies <NUM> to slide in the second direction Y-Y with respect to the jaws <NUM>, each of the parts of the clamping hole <NUM> extending into one of the spacing bodies <NUM> is elongated in the second direction Y-Y, being shaped for example like a clamping slot. As an alternative to the elongation in the second direction Y-Y, the clamping hole <NUM> can simply have a larger diameter than the stem <NUM> of the clamping element <NUM>, in order to allow some backlash to the stem <NUM>.

With the arrangement of the wedge surfaces <NUM> described for <FIG>, it is obtained that, during the clamping of the jaws <NUM>, the two spacing bodies <NUM>, sliding in the second direction Y-Y, are each pressed against the adjacent terminal <NUM>. A pressure is thus obtained in the second direction Y-Y which is a pressure for mutually distancing the terminals <NUM>, and is exerted by the abutment surfaces <NUM> of the spacing bodies <NUM> on the contact surfaces <NUM> of the respective terminals <NUM>.

This pressure, while being in a direction of mutual distancing of the terminals <NUM>, improves the electrical contact therebetween. In fact, there is significant pressure both between each contact surface <NUM> and each respective abutment surface <NUM>, to exchange current between the terminals <NUM> and the spacing block <NUM>, and between the wedge surfaces <NUM>, to exchange current between the two spacing bodies <NUM> of the spacing block <NUM>.

It should be noted that the side elements <NUM> prevent the terminals <NUM> from moving excessively away in the second direction Y-Y, and thus from loosening the contact pressure. Therefore, with the clamping of the jaws <NUM>, each terminal <NUM> is compressed in the second direction Y-Y between one of the spacing bodies <NUM>, on the one hand, and side elements <NUM>, for example a pair of arms of distinct jaws <NUM>, on the other.

<FIG> shows a third embodiment, similar to that of <FIG>. However, the jaws <NUM> are not U-shaped, but L-shaped. Furthermore, the spacing block <NUM> is always composed of two spacing bodies <NUM> with the wedge surfaces <NUM>, but these are each integrally formed with a respective jaw <NUM>. Precisely, each spacing body <NUM> protrudes from the base <NUM> of a respective jaw <NUM> at least in part in the first direction X-X, towards the base <NUM> of the opposite jaw <NUM>.

In such a case, the spacing bodies <NUM> do not have secondary surfaces <NUM>.

During the clamping, the spacing bodies <NUM>, as well as the entire jaws <NUM>, translate partially in the first direction X-X and partially in the second direction Y-Y. The clamping holes <NUM>, <NUM> of the jaws <NUM> and of the respective spacing bodies <NUM> are coincident. They allow a clearance in the second direction Y-Y of the stem <NUM>.

In the preferred embodiments, the device <NUM> is completed by a casing <NUM>, made of electrically insulating material. The casing <NUM> encloses the jaws <NUM>, and preferably also the side elements <NUM> (which can be part of the jaws <NUM>), as well as any other component arranged in the seat therebetween.

In some of the illustrated embodiments (<FIG>, <FIG>, <FIG>, <FIG>), there is no casing <NUM> enclosing the jaws <NUM>, but optionally other types of insulating coatings <NUM>, positioned in particular so as to allow several devices <NUM> to be placed side by side along the first direction X-X, avoiding electrical contacts between the jaws <NUM>.

Where present, the casing <NUM> comprises support elements, shaped to support at least the jaws <NUM> and keep them in the correct position, still allowing the described movements which occur during the clamping.

If the side elements <NUM> are not directly connected to the jaws <NUM>, they can also be supported and maintained in position always by the support elements of the casing <NUM>. Therefore, the casing <NUM> can form an example of indirect connection between each side element <NUM> and at least one of the jaws <NUM>, and/or between the two side elements <NUM>.

Alternatively, the side elements <NUM> can be connected to the clamping element <NUM>, or to the spacing block <NUM>.

This function of holding the side elements <NUM> in place prevents, for example, the distancing pressures of the terminals <NUM> from causing a retraction of the side elements <NUM>, causing a worsening of the electrical connection. This is of course not required by the casing <NUM> if the side elements <NUM> are arms of the jaws <NUM>.

It should be noted that based on the type of connection chosen, the side elements <NUM> can be substantially fixed to, or they can translate together with, the jaws <NUM> during the clamping thereof.

The support elements of the casing <NUM> can also be shaped to support and hold in place one or more of the spacing blocks <NUM>.

Preferably, the clamping element <NUM> emerges at least in part from the casing <NUM>, so that it can be clamped without removing the casing <NUM>. In particular, the head <NUM> of the screw and the nut <NUM> both emerge from the casing <NUM>.

The casing <NUM> has at least one opening <NUM> for inserting and extracting the terminals <NUM> into/from the seat. In the illustrated embodiment there is a further opening <NUM>, for accessing the inner components from above, opposite the opening <NUM>.

By virtue of the casing, the coupling device <NUM> is more easily handled, by a user or automated machinery responsible for fitting the coupling device on a pair of terminals <NUM>, in order to introduce the terminals <NUM> into the seat and couple the terminals <NUM> to each other.

In particular, various parts of the casing <NUM> can be shaped to guide, during the assembly of the device <NUM>, the jaws <NUM> and various other components in the correct position, as well as to guide the terminals <NUM> in the seat. Thus the implementation of the coupling device <NUM> is also simplified.

The guides and the support elements of the casing also allow the correct positioning of components which are slightly different from each other due to machining tolerances.

<FIG>, <FIG> show examples of a pair of coupling devices <NUM>, according to a fourth embodiment, each of which couples more than two terminals <NUM> simultaneously, in particular eight terminals <NUM> each. Seven spacing blocks <NUM> divide the seat into eight compartments for the respective terminals <NUM>.

Those skilled in the art will understand that this can be useful for example for connecting in series two groups of cells <NUM>, and in particular a first group of four cells <NUM>, for which a terminal <NUM> of a first polarity is connected, and a second group of four cells <NUM>, for which a terminal <NUM> of a second polarity is connected. However, there are no a priori limits on the type of polarity of the terminals <NUM> to be connected, as well as on their positioning in series or in parallel.

Otherwise, this embodiment is similar to that of <FIG>, in that each spacing block <NUM> consists of two spacing bodies <NUM> formed in a single piece with respective jaws <NUM>. The blocks and the spacing bodies <NUM>, <NUM> are spaced from each other in the second direction Y-Y. Each jaw <NUM> is thus comb-shaped.

Some of the terminals <NUM>, with the clamping of the jaws <NUM>, are compressed between two abutment surfaces <NUM> of distinct spacing bodies <NUM>. Other terminals <NUM> are compressed between an abutment surface <NUM> of a spacing body <NUM>, and one of the side elements <NUM>.

A single arm of one jaw <NUM> on one side and a single arm of the other jaw <NUM> on the other side are included as side elements <NUM>.

For greater structural stability, not a unique clamping element <NUM> is provided, but a plurality of clamping elements <NUM>, in particular three.

<FIG> shows a fifth embodiment which allows connecting more than two terminals <NUM>. In this case, adjacent terminals <NUM> are connected two by two, substantially in the same manner as <FIG> and <FIG>, in particular with wedge surfaces <NUM> formed in the jaw arms <NUM>.

However, a single casing <NUM> (formed in two parts) of the device <NUM> does not enclose only one pair of jaws <NUM>, but a plurality of independent pairs of jaws <NUM>. The different pairs of jaws <NUM> are spaced apart at least partly in the second direction Y-Y.

To save space, some of the pairs of jaws <NUM> are also offset from each other in a third direction, perpendicular to the first and second directions X-X, Y-Y.

The clamping elements <NUM> have been omitted from this figure, but one is included for each pair of jaws <NUM>, as understandable by the clamping holes <NUM> visible in the figure.

In <FIG>, sixth embodiment, a single device <NUM> couples more than two terminals <NUM>. This resembles the embodiment of <FIG>, in that each spacing block <NUM> consists of two spacing bodies <NUM> which are not integrally formed with the jaws <NUM>.

Each jaw <NUM> is L-shaped, with a single arm identifying a respective side element <NUM>.

A casing <NUM> has not been illustrated, but is preferably included, in particular for the support of at least those spacing bodies <NUM> which are not crossed by any clamping element <NUM>.

The seventh embodiment of <FIG> is similar to those of <FIG>. In fact, the wedge surfaces <NUM> are formed in distinct spacing bodies <NUM> separated from the jaws <NUM>. However, in this embodiment the casing <NUM> is depicted, which supports the spacing bodies <NUM>.

Furthermore, the side elements <NUM> are not integrally formed with the jaws <NUM>, but are separate elements mounted on respective clamping elements <NUM>. Precisely, exactly two side elements <NUM> are included.

Each side element <NUM> is then held integral with a respective jaw <NUM> by at least one of the clamping elements <NUM>. For this purpose, each side element <NUM> is provided with its own clamping hole (not shown) aligned with a clamping hole <NUM> of a jaw <NUM>.

It should be noted that the conical washers <NUM>, as illustrated, may not directly lie on the jaws <NUM>, but for example on the side elements <NUM>.

The eighth embodiment, in <FIG>, is similar to that of <FIG>, for the presence of side elements <NUM> which are distinct from the jaws <NUM>. However in this embodiment, there are four side elements <NUM>, and not two. Furthermore, the wedge surfaces <NUM> are formed in the side elements <NUM>, and not in spacing bodies <NUM>. In particular, for this embodiment it is not envisaged that the spacing blocks <NUM> are each divided into distinct spacing bodies <NUM>. However, they are always supported by the casing <NUM>, at least where they are not already supported by the clamping elements <NUM>.

Claim 1:
Coupling device (<NUM>) for coupling two or more tab electric terminals (<NUM>), comprising:
- a pair of jaws (<NUM>) spaced apart from each other in a first direction (X-X), each jaw (<NUM>) having a base (<NUM>) with two end portions, the bases (<NUM>) of the jaws (<NUM>) delimiting in the first direction (X-X) a seat therebetween, the seat being adapted to receive therein two or more tab electric terminals (<NUM>), so that respective electrical contact surfaces (<NUM>) of the terminals (<NUM>) face each other in a second direction (Y-Y), transverse to the first direction (X-X),
- at least one clamping element (<NUM>) configured to clamp the jaws (<NUM>) towards each other in the first direction (X-X),
- side elements (<NUM>) spaced apart from each other in the second direction (Y-Y) to delimit the seat in the second direction (Y-Y), each side element (<NUM>) being an arm of a respective jaw (<NUM>), connected to an end portion of the base (<NUM>) of the respective jaw (<NUM>), or each side element (<NUM>) being distinct from the jaws (<NUM>) and connected at least indirectly to a respective jaw (<NUM>) so as to translate in the first direction (X-X) together with said jaw (<NUM>) during the clamping of the jaws (<NUM>),
- at least one electrically conductive spacing block (<NUM>), arranged in the seat so as to be placed between the terminals (<NUM>), when they are present in the seat, the spacing block (<NUM>) having two opposite abutment surfaces (<NUM>), each arranged so as to face a respective contact surface (<NUM>) of a respective terminal (<NUM>), when it is present in the seat, wherein at least one of the side elements (<NUM>) has a wedge surface (<NUM>), that is inclined with respect to the first and the second direction (X-X, Y-Y),
characterized in that said wedge surface (<NUM>) is arranged and inclined so as to act on at least one terminal (<NUM>) at a face (<NUM>) of the terminal (<NUM>) opposite the contact surface (<NUM>), and to convert a pressure in the first direction (X-X), exerted by clamping the pair of jaws (<NUM>), into a pressure for mutual approach of the terminals (<NUM>) in the second direction (Y-Y), when they are present in the seat, so as to press in the second direction (Y-Y) the contact surfaces (<NUM>) of the terminals against the respective abutment surfaces (<NUM>) of the spacing block (<NUM>).