Patent Description:
Electrical crimp terminals are widely used for connecting an electrical cable to an electrical connector, for example in the production of wire harnesses for the automotive industry.

Examples of electrical connectors with electrical crimp terminals are known for example from the documents <CIT>, <CIT>, <CIT>, <CIT> <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>. In these documents the electrical crimp terminal is particularly shaped to provide particular advantages, i.e. strengthening the connector between insulation connection portion and core connection portion.

<CIT> relates to a conductor end sleeve mounted on a conductor end portion by crimping, and to a blank for producing such a conductor end sleeve.

<CIT> relates to a cable crimping device comprising a base wire crimping portion having a base portion and a crimping piece portion extending from a side of the base portion and crimping a core wire comprising a plurality of wires of the electric wire, And a surface of the core crimping portion facing the base portion is a tapered surface that is inclined in a direction gradually separated from the core wire toward an end in the axial direction of the core wire.

<CIT> relates to an electric terminal crimping method and the assembly obtained by this method.

<CIT> discloses a crimp barrel comprising a base part and at least two deformable crimping wings in order to make a crimped connection with a wire, whereby the crimping wings each have a first zone connected to the base part, a second zone, and a middle zone situated between the first zone and the second zone, whereby the base part is thicker than the middle zone of the crimping wings, the first zone tapers from the base part towards the middle zone, at least on a first side, and the second zone tapers further starting from the middle zone, at least on a second side that is opposite from the first side.

However, such electrical crimp terminals of the prior art nevertheless may show a low crimp performance in terms of electrical and mechanical reliability. Thus, they may be prone to failure due to a disconnection between wire and connector. Further, some crimp terminals comprise a L-shaped geometry in a non-crimped condition, which requires two distinct crimp portions in the conductor or core crimp area. Therefore, such L-shaped geometry requires more space or terminal length due to the space between the two crimp portions and special tools for crimping such terminals. Other electrical crimp terminals even require three distinct crimp portions for crimping the conductor.

Thus, there is a need to improve the mechanical and electrical reliability of an electrical crimp terminal without increasing the size of the electrical connector and without requiring special tools for crimping.

The above-mentioned problems are solved by an electrical crimp terminal according to claim <NUM>.

Particularly, the above mentioned problems are solved by an electrical crimp terminal for connection with a conductor of an electrical cable having an insulation surrounding the conductor, the electrical crimp terminal comprising a conductor connection portion, wherein the conductor connection portion comprises conductor crimp wings to be crimped onto the conductor of the electrical cable; wherein each of the conductor crimp wings in the non-crimped state have at least one progressive portion having a progressively increasing height h(L)in a longitudinal direction L to a tip of the conductor to be crimped.

By having conductor crimp wings that comprises a progressive portion with a height that increases along the longitudinal direction of the electrical crimp terminal, the wire compression onto the conductor increases along the length of the crimp terminal from a low wire compression at the rear of the conductor connection portion to a high wire compression at the front of the conductor connection portion. This progressive wire compression results from providing more material of the conductor crimp wings towards the tip of a conductor to be crimped and using a standard crimping tool with a standard terminal crimp barrel.

Having such a progressive core crimp geometry provides a perfect a smooth wire compression with optimal electrical and mechanical crimp performances. Because of the lower wire compression at the insertion end / rear of the conductor connection portion further the risk for breaking the conductor during wire pull out test is significantly reduced.

In addition, the electrical crimp terminal according to the present disclosure is compatible with existing standard terminal crimp barrels and does not require tool changes as for the crimp terminals with two or more distinct crimping portions for the conductor. This safes effort and costs for providing special tooling.

Further, the progressive core crimp geometry of the conductor connection portion of the electrical crimp terminal according to the present disclosure does not require more space than a conventional crimp terminal. Thus, no design changes are required for the devices to be connected.

The progressive portion of at least one conductor crimp wing may comprises at least one notch. It is possible that the progressive portion of both conductor crimp wings comprises at least one notch. A notch is an interruption or indentation of the progressive portion. The notch divides the smooth reduction of the compaction level of the progressive portion into two parts or compaction areas. For example, wire compression at a rear of the conductor connection portion may lowest and wire compression at a front may be highest. The notch allows these two areas to be mechanically decoupled. This effects improved mechanical strain relief and shock-absorption properties while still ensuring a good electrical connection. For example, the micromovement of the conductor may be kept away from the high compression area. For example, if the conductor is used for signal transmission, an impedance mismatch can thus be reduced, and therefore reflections of the signal can be reduced which leads to higher data transmission rates and better signal integrity.

The notch may comprise a depth d which is less than <NUM>% of the height h(L) of the progressive portion at the position of the notch. Such a notch can be referred to a shallow notch and can effect preferred shock-absorption properties while ensuring that mechanical stability is maintained. The greater the depth, the better the shock-absorption properties but at the same time the mechanical stability can start to become affected. A preferred depth d is between <NUM> and <NUM>%, more preferred <NUM>% and <NUM>%, most preferred <NUM> % to <NUM>% of the height h(L) of the progressive portion at the position of the notch.

The notch may comprise a notch width w, wherein the notch width w is less than <NUM>% of the complete length l of the conductor crimp wings. The greater the notch width, the more the high-compression area becomes isolated from the low-compression area. However, if the width is too large, the crimp becomes unstable. A preferred width w is about <NUM> to <NUM>%, more preferred <NUM> to <NUM>%, most preferred <NUM> to <NUM>% of the complete length l of the conductor crimp wing.

The contour of the notch may comprise any suitable shape. For example, the contour may be of a circular shape (then the depth d = the width w, both measured in mm), essentially circular shape (then the depth d ≈ the width w, both measured in mm) or of an elliptical shape (d≠w, both measured in mm). The term "essentially circular shape" means allowing for deviations of about <NUM> % in width or depth from a circular shape. An essentially circular shape may offer improved shock-absorption properties. It is also possible that the contour of the notch has a parabolic or hyperbolic shape.

The progressive portion of at least one, or of both of the conductor crimp wings may comprise more than one notch, for example, two, three, or four notches. The notches may be similar in structure, such as their depth and width or their structure, e.g. their respective depth or width may be different. It may be particularly advantageous to have several notches per conductor crimp wing as it allows for a gradual mechanical decoupling of a highest-compression area from a lowest-compression area.

The progressive portion extends along the complete length l of each conductor crimp wing. Thus, from the rear to the front of the conductor connection portion the compression force onto the conductor increases linearly. The conductor crimp wings may have the same length or substantially the same length, wherein substantially the same length means the same length within allowable deviations of about <NUM>%.

Alternatively it is possible that the progressive portion extends only along at least <NUM>%, preferably at least <NUM>%, preferably at least <NUM>%, preferably at least <NUM>% and preferably at least <NUM>% of the length l of the conductor crimp wings.

Preferably, the height h of the progressive portion increases linearly. This provides for a substantially linear increase in compression force along the length of the crimp terminal.

Preferably, the height h of the progressive portion increases non-linearly. Depending on the diameter and material of the conductor a non-linear increase in height h of the progressive portion and thus a non-linear increase in compression force onto the conductor along the length of the crimp terminal may be selected to provide optimized crimping performance.

Preferably, the conductor crimp wings, in the non-crimped state, at the progressive portion comprise an upper edge that is slanted by an angle α.

Preferably, the angle α ranges from <NUM>° to <NUM>°, preferably from <NUM>° to <NUM>°, more preferably from <NUM>° to <NUM>° and most preferably from <NUM>° to <NUM>°. Thus, the linear increase of the compression force onto the conductor can be adjusted by the angle α of the slanted upper edge of the progressive portion and adapted to different conductor diameters, conductor types, i.e. solid or strand wire, and materials.

Preferably, the conductor connection portion further comprises a conductor connection bottom portion, wherein the conductor crimp wings are integrally connected with their respective lower edges to the conductor connection bottom portion.

Preferably, the electrical crimp terminal further comprises an insulation connection portion, mechanically connected with the conductor connection portion, wherein the insulation connection portion comprises insulation crimp wings to be crimped onto the insulation of the electrical cable. The insulation connection portion further significantly increases mechanical stability of the electrical crimp terminal. Preferably, the insulation connection portion is to be crimped structurally independent from the conductor connection portion.

Preferably, the insulation connection portion further comprises an insulation connection bottom portion, wherein the insulation crimp wings are integrally connected with their respective lower edges to the insulation connection bottom portion. Preferably, the insulation connection bottom portion is connected with the conductor connection bottom portion.

Preferably, the transition between the upper edge and a front side edge and/or a rear side edge of the crimp wings is rounded. Such rounded transition avoids excessive compression force at the rear and at the front end of the conductor connection portion and thus further reduces the risk of breaking the crimped conductor.

Preferably, the transition between the upper edge and the rear side edge and/or the front side edge of the crimp wings is rounded by a radius r1, r2, respectively, that preferably ranges from <NUM>% to <NUM>%, more preferably from <NUM>% to <NUM>% or most preferably from <NUM>% to <NUM>% of the length l of the conductor crimp wings.

Preferably, the crimp wings along the upper edge thereof, comprise a chamfer. This chamfer facilitates introduction of the crimp wings into the strands of the conductor and thus facilitates the crimping process.

Preferably, the chamfer <NUM> is slanted by an angle β with respect to the plane of the crimp wings, wherein the angle β ranges from <NUM>° to <NUM>°, preferably from <NUM>° to <NUM>°.

In the following, preferred embodiments of the present disclosure are disclosed by reference to the accompanying figures, in which shows:.

In the following preferred embodiments of the present disclosure are described with respect to the figures.

<FIG> shows a side view of an exemplary electrical crimp terminal <NUM> in a non-crimped state. <FIG> shows a side view of the electrical crimp terminal <NUM> of <FIG> in a state crimped to an electrical cable <NUM>. A corresponding essentially flat blank of the electrical crimp terminal <NUM> is shown in <FIG>.

The electrical crimp terminal <NUM> comprises a conductor connection portion <NUM> with two oppositely arranged conductor crimp wings <NUM>, <NUM> for connection to an electrical cable <NUM> (see <FIG>). The electrical crimp terminal <NUM> further comprises an arbitrary terminal contacting area <NUM>, that can for example be in form of a fork, a lug (see. <FIG>), a plug, a pin, a socket or in a different form as required for the electrical connector. In <FIG> the terminal contacting area <NUM> is only shown partially.

The electrical crimp terminal <NUM> is usually made of a sheet metal, e.g. out of copper or brass or other suitable metal, stamped out of the sheet metal and bent from an essential flat blank as shown in <FIG> into the non-crimped form as shown in <FIG>, <FIG> and <FIG>. Referring to <FIG>, a right conductor wing <NUM> and a left conductor wing <NUM> are to be crimped around a conductor <NUM> of the electrical cable <NUM> for providing an electrical and mechanical connection of the electrical crimp terminal <NUM> with the electrical cable <NUM>.

As shown in <FIG> and in more detail in <FIG> the two conductor wings <NUM>, <NUM> in the non-crimped state have at least one progressive portion <NUM> having a progressively increasing height h(L) in a longitudinal direction L to a tip <NUM> of a conductor <NUM> of the cable <NUM> to be crimped. The longitudinal direction L extends parallel to the longitudinal axis Lx of the electrical crimp terminal <NUM>, see <FIG>. The longitudinal axis Lx and the longitudinal direction L is further parallel to the longitudinal axis of the electrical cable <NUM> crimped within the electrical terminal <NUM>.

Thus, the height h(L) depends on the longitudinal direction L and progressively increases along the longitudinal axis of the electrical cable <NUM> to the tip <NUM> of the conductor. This means that from the rear <NUM> of the progressive portion <NUM> facing the electrical cable <NUM> to the front <NUM> of the progressive portion <NUM> facing a tip <NUM> of the conductor <NUM>, the height h(L) of the conductor wings <NUM>, <NUM> increases. Thus, progressively more material to be crimped is provided from the rear <NUM> to the front <NUM> of the conductor connection portion <NUM>. Therefore, when the conductor connection portion <NUM> is crimped by a standard crimping tool around the conductor <NUM> as shown in <FIG>, the wire compression at the rear <NUM> of the conductor connection portion <NUM> is lowest and the wire compression at the front <NUM> is highest.

As shown in <FIG> and <FIG> an upper edge <NUM> of the conductor wings <NUM>, <NUM> from left to right is slanted upwards by an angle α to a horizontal plane in the longitudinal direction L and is straight. Thus, also the wire compression is linearly increasing from the rear <NUM> to the front <NUM> of the conductor connection portion <NUM>. Preferably the angle α can range from <NUM>° to <NUM>°, preferably from <NUM>° to <NUM>°, more preferably from <NUM>° to <NUM>° and most preferably from <NUM>° to <NUM>°. The angle α can depend on the type, diameter and material of the conductor <NUM> and a length <NUM> of the conductor crimp wings <NUM>, <NUM> or the length of the progressive portion <NUM>.

As shown in <FIG> and <FIG>, preferably, the extended width W(L) of a blank forming the progressive portion <NUM> of the conductor connection portion <NUM> increases along the longitudinal direction L preferably from the rear <NUM> to the front <NUM> of the progressive portion from a minimal extended width W1 to a maximal extended width W2. Preferably, the maximal extended width W2 at the front side edge <NUM> of the progressive portion <NUM> is at least <NUM>% longer than the minimal extended width W1 at the rear side edge <NUM>. Preferably, the extended width W2 is from <NUM>% - <NUM>% and more preferred about <NUM>% longer than the extended width W1.

It is preferred that the progressive portion <NUM> of the conductor connection portion <NUM> extends along the complete length l of the conductor crimp wings <NUM>, <NUM>. However, it should be noted that the progressive portion <NUM> of the conductor connection portion <NUM> can also extend only along a part of the length l conductor connection portion <NUM> or the conductor crimp wings <NUM>, <NUM>. Preferably, the progressive portion <NUM> can extend along at least <NUM>%, preferably at least <NUM>%, preferably at least <NUM>%, preferably at least <NUM>% and preferably at least <NUM>% of the length l of the conductor crimp wings <NUM>, <NUM>. By such a design the compression force can be variably set along the length l of the conductor connection portion <NUM> with areas of constant compression force and areas with progressively increasing compression force. Further, it is possible to provided more than one, for example, two or three, individual progressive portions <NUM> at one conductor crimp wing <NUM>, <NUM>. This can further be used to particularly determine the compression force of the crimped conductor connection portion.

Further, the height h(L) of the progressive portion <NUM> can linearly increase, as particularly shown in <FIG>, <FIG> and <FIG> but other non-linear increases of the height h(L) can also be possible. Thus, for example, exponential or hyperbolic increases of the height h(L) of the progressive portion <NUM> can be used.

As shown in <FIG> the conductor connection portion <NUM> further comprises a conductor connection bottom portion <NUM>, wherein the two conductor crimp wings <NUM>, <NUM> are integrally connected with their respective lower edge <NUM> to the conductor connection bottom portion <NUM>. The conductor connection bottom portion <NUM> may be curved or rounded in section on the top-side to fit to the original shape of the conductor <NUM> and to provide a good transition of the conductor connection bottom portion <NUM> to the conductor crimp wings <NUM>, <NUM>.

As shown in <FIG> and <FIG> the transition between the upper edge <NUM> and a front side edge <NUM> and/or a rear side edge <NUM> of the crimp wings <NUM>, <NUM> can be rounded. Preferably, the transition is rounded by a radius r1, r2, respectively, that preferably ranges from <NUM>% to <NUM>%, more preferably from <NUM>% to <NUM>% or most preferably from <NUM>% to <NUM>% of the length l of the conductor crimp wings <NUM>, <NUM>. Particularly, the rounded transition at the rear of the conductor connection portion <NUM> having a radius ri facilitates a smooth application of the compression force to the conductor <NUM> in this area. This further decreases the risk of a break or weakening of the conductor <NUM>.

Further, as particularly shown in <FIG> the crimp wings <NUM>, <NUM> along the upper edge <NUM> thereof, may comprise a chamfer <NUM> that may facilitate crimping of the conductor connection area <NUM>. Preferably, the chamfer <NUM> is slanted by an angle β with respect to the plane <NUM> of the conductor crimp wings <NUM>, <NUM>, wherein the angle β ranges from <NUM>° to <NUM>°, preferably from <NUM>° to <NUM>.

The conductor crimp wings <NUM>, <NUM> can further comprise ridges <NUM>, as shown in <FIG> and <FIG> on the inner sides thereof to improve the holding force for the conductor <NUM> to be held by the conductor connection portion <NUM>. The ridges <NUM> deform the outer side of the conductor <NUM> to provide a form fit of the connection between conductor <NUM> and the electrical crimp terminal <NUM>.

If the conductor crimp wings <NUM>, <NUM> comprise ridges <NUM> and if one or both conductor crimp wings <NUM>, <NUM> comprises at least one notch, it is possible and preferable that the ridges <NUM> do not overlap with any of the notches so that the ridges <NUM> effect on the holding force is not diminished (<FIG> shows one such example).

<FIG> and <FIG> show a further embodiment of an electrical crimp terminal <NUM>. The electrical crimp terminal <NUM> of <FIG> and <FIG> comprises the conductor connection portion <NUM> as described with respect to <FIG>, and further comprises an insulation connection portion <NUM> for connecting the terminal <NUM> with the insulation <NUM> of the electrical cable <NUM>. The insulation connection portion <NUM> is mechanically connected with but distanced from the conductor connection portion <NUM> and comprises a right insulation crimp wing <NUM> and a left insulation crimp wing <NUM> arranged on opposite sides of an insulation connection bottom portion <NUM>. The insulation connection bottom portion <NUM> is curved or rounded in section on the top-side to also fit to the original shape of the insulation <NUM> and to provide a good transition of the insulation connection bottom portion <NUM> to the insulation crimp wings <NUM>, <NUM>. The insulation crimp wings <NUM>, <NUM> are offset from each other, such that they are located side by side in the crimped state, as shown in <FIG>. The insulation crimp wings <NUM>, <NUM> are integrally connected with their respective lower edges <NUM> to the insulation connection bottom portion <NUM>.

The electrical crimp terminal <NUM> of <FIG> and <FIG> further comprises a terminal contacting area <NUM> in the form of a lug area integrally connected to the conductor connection portion <NUM> in the longitudinal direction L. Of course, other terminal contacting areas <NUM> can also be provided like for example in the form of a fork, a plug, a pin or a socket.

The electrical cable <NUM> can be of different types, materials and diameters. The conductor <NUM> can be stranded and comprise a number of individual wires or the conductor can be made of a single solid wire. Common materials for the conductor <NUM> are copper, silver coated copper, gold coated copper, tin coated copper, aluminum or other electrically conducting materials. The insulation <NUM> commonly consists of a nonconducting plastic material.

<FIG> show a side view of an exemplary electrical crimp terminal <NUM> in a non-crimped state similar to <FIG> described above. The crimping process is similar to that illustrated above, e.g. in the context of <FIG>. In <FIG>, the progressive portion <NUM> of each of the two conductor crimp wings <NUM>, <NUM> comprises a notch <NUM>. The notch <NUM> comprises a depth d. In this example, the depth d is measured at a right angle <NUM> from the upper edge of crimp wing <NUM>. In other words, the angle <NUM> between upper edge of crimp wing <NUM> and the notch depth d is <NUM> degrees.

<FIG> shows an example of a shallow notch, wherein the depth d is less than <NUM> % of the height h(L) at the longitudinal position <NUM> of the notch. In this example, the depth d of the notch <NUM> is about <NUM> % of the height h(L) of the progressive portion at the longitudinal position <NUM> of the notch. In the context a crimp terminal <NUM> comprising a notch, the height h(L) is the fictional height at the position <NUM> of the upper edge of crimp wing <NUM> if the notch <NUM> were not present and can be constructed by drawing a straight line through the first lateral end <NUM> and the second lateral end <NUM> of the notch <NUM>. The longitudinal position <NUM> of the notch is measured at the centre of the notch as indicated. The contour of the notch <NUM> comprises an essentially circular shape, i.e. the depth d ≈ the width w (both measured in mm) of the notch <NUM>.

<FIG> shows an example of a deep notch, wherein the depth d is at least <NUM> % of the height h(L) at the longitudinal position <NUM> of the notch. In this example, the depth d is about <NUM> % of the height h(L) at the longitudinal position <NUM> of the notch. Since the depth d is measured at a right angle <NUM> from the upper edge of crimp wing <NUM>, it can be larger than the height h(L) if the slant angle α ≠ o. In <FIG>, the contour of the notch has an elliptical shape (d≠w, both measured in mm).

In <FIG>, the notch <NUM> comprises a notch width w, wherein the notch width w is less than <NUM>% of the complete length <NUM> of each conductor crimp wings <NUM>, <NUM>. In <FIG>, the width w is about <NUM> % of the complete length l of each conductor crimp wing <NUM>, <NUM>. However, it is alternatively possible for the notch width w to be larger than <NUM>% of the complete length l of each conductor crimp wings <NUM>, <NUM>.

<FIG> shows a similar view as <FIG> shown above. The two conductor wings <NUM>, <NUM> in the non-crimped state each have a progressive portion <NUM> having a progressively increasing height h(L) in a longitudinal direction L to a tip <NUM> of a conductor <NUM> of the cable <NUM> to be crimped. In the example of <FIG>, the progressive portion <NUM> of the conductor crimp wing <NUM> comprises three notches 61a, 61b, and 61c, while the opposing conductor crimp wing <NUM> does not comprise a notch.

Claim 1:
Electrical crimp terminal (<NUM>) for connection with a conductor (<NUM>) of an electrical cable (<NUM>) having an insulation (<NUM>) surrounding the conductor (<NUM>), the electrical crimp terminal (<NUM>) comprising a conductor connection portion (<NUM>), wherein the conductor connection portion (<NUM>) comprises conductor crimp wings (<NUM>, <NUM>) for being crimped onto the conductor (<NUM>) of the electrical cable (<NUM>); wherein each of the conductor crimp wings (<NUM>, <NUM>) in the non-crimped state has at least one progressive portion (<NUM>) having a progressively increasing height (h(L)) in a longitudinal direction (L) to a tip (<NUM>) of the conductor (<NUM>) to be crimped characterized in that the progressive portion (<NUM>) extends along the complete length (l) of each conductor crimp wing (<NUM>, <NUM>).