The present disclosure relates to a crimp with increased robustness and thinner stock material.
In electronics and electrical engineering, there are known a large number of electromechanical connections, which serve to transmit electrical currents, electrical voltages and/or electrical signals with the greatest possible range of currents, voltages, and frequencies and/or data rates. Such connections must temporarily, where applicable after a comparatively long period of time, or permanently ensure correct transmission of mechanical contact, electrical power electrical signals and/or data under thermally loaded, dirty, damp and/or chemically aggressive conditions. Therefore, a large number of specially constructed electromechanical contacts, in particular crimp contacts are known.
A crimp connection is a solderless connection. Crimping connection is advantageous over normal pinching the terminal on to the end of a wire. The shape of crimp and amount of pressure applied must be correct in order to obtain desired performance and durability of the connection. Improper crimps may generate heat due to poor electrical connection and may result in the rework of the product, increase scrap and in extreme cases catastrophic failure.
Electrical terminals are often used to terminate the ends of wires. Such electrical terminals typically include an electrical contact and a crimp barrel. In some terminals, the crimp barrel includes an open area that receives an end of the wire therein. The crimp barrel is crimped around the end of the wire to establish an electrical connection between electrical conductors in the wire and the terminal as well as to mechanically hold the electrical terminal on the wire end. When crimped over the wire end, the crimp barrel establishes an electrical and mechanical connection between the conductors of the wire and the electrical contact.
In addition to a permanent electrical connection, a permanent mechanical connection must also be produced between the cable and a conductor crimp region of the crimp contact by means of a contact. For an electromechanical connection, the crimp contact has a conductor crimp region and in most cases an insulation crimp region for the cable. Miniaturization and cost savings are forcing manufacturers towards smaller and thinner contacts.
Crimp connections known in the art serve to establish an electrical contact as well as to provide a mechanically resilient connection between a crimping base and at least one electrical conductor, which can consist of one or more individual wires. The crimp barrel usually consists of a metal plate, which is bent to have a U- or V-shaped cross-section or has rectangular cross-section with a flat base. The underside of the U-or V-shape is

hereinafter referred to as crimp base. The upwardly pointing legs of the U-or V-shape are generally known as crimp flanks.
The crimp connection is produced by means of a crimping die, which consists of anvil and crimping stamp. For crimping, the crimping base is positioned centrally on the anvil, and the electrical conductor is placed between crimping legs on the crimping barrel. Subsequently, the crimping stamp descends onto the anvil and bends the crimp flanks around the electrical conductor in order to compress it tightly and to fix it in a force-locking manner with the crimping barrel. In the transition area from the crimp base to the crimp side-walls, the so-called crimping roots, as well as laterally at the crimp side-walls, zones of high bending stresses are formed in the crimp barrel.
The force connection between the crimp barrel and the electrical conductor can be improved by providing additional form-fitting elements for example, recesses or depressions on the inner side of the crimp barrel facing the conductor for the creation of locking elements, wherein displaced conductor material can penetrate into the recesses during compression.
The pressed zones of a crimping connection have better electrical properties. The less heavily pressed areas have a higher mechanical stability.
The crimping barrel and the electrical conductor can be locally reinforced by means of steps or projections in the crimping die.
US Pat. No. 5,901,439 discloses how the compression can be locally increased by feeding an additional punch through an opening in the working surface of the anvil when the crimping die is closed.
Patent Application DE 10 2006.045 567A1 describes a staggered seam on an F-Crimp formed by a crimp tool with consecutive offset in the roll-in geometry. In this crimp connection, the crimp with a thinner sheet metal presents the problems mentioned above.
If the crimp connection is subjected to mechanical stress, the crimping flanks may spring up along the crimping roots and other zones of high bending stresses. There is the risk that the crimping base opens along the longitudinal seam at the ends of the crimp side-walls. Depending on the type of stress, the ends of the crimp side-walls can also move axially relative to each other. Moreover, a reduction in the crimping forces in the prior art is favored in that the individual wires of the electrical conductor can move relative to each other. When they are displaced in the longitudinal direction, the force of the crimped connection is reduced by the resultant free spaces. The free spaces offer the possibility of external material penetrating into the crimped connection. The crimping forces are then further

weakened by corrosion of the electrical conductor and the crimping barrel caused by the external agents.
In the event of a loss of crimping force, the desired mechanical stability of the crimping connection can no longer be maintained. It was found that in case of movements on the connected line or the electrical conductor, a movement of the individual wires of the electrical conductor at the other end of the crimp connection can be observed. This indicates that both the individual wires of the electrical conductor, as well as the electrical conductor and the crimp barrel are no longer fixed in a sufficiently secure manner. In the individual case, therefore, increased electrical transition resistances between the crimp barrel and the electrical conductor can occur.
To achieve mechanical and electrical robustness of the crimp connection, the crimp barrel must have sufficient stock thickness of the sheet metal related to the wire size. Especially for large wire sizes this minimum barrel stock thickness creates disadvantages as it presents the difficulty in cutting, bending, or forming in the stamping process to manufacture an electrical element from sheet metal, and requires high force for crimping and requires high material costs.
On the other hand, when using too thin stock, the crimp starts to fail at the seam of the roll-in for mechanical and electrical performance.
The measures known in the art for providing form-locking elements or a reinforced crimping connection elements cannot prevent the crimp barrel from being deflected, as well as a relative movement of the individual wires of the electrical conductor and the resulting losses of crimping forces.
One of the non-limiting and exemplary embodiments provides a crimping connection including a staggered seam that may solve the aforementioned problems.
In one general aspect a crimp for connecting wires comprises at least one crimp barrel, wherein the crimp barrel comprises at least one base and at least two opposing side walls extending from the base, wherein the side-walls are adapted for bending around the wires such that ends of the opposing side-walls engage with one another along a staggered seam.
Advantageously, the ends of the opposing side-walls are provided with at least one embossed area and at least one deepened area on the outer surface of the crimp barrel such that the embossed area of a first side-wall engages with the deepened area of a second side-wall.

Advantageously, the deepened areas are provided with interlock surfaces.
Advantageously, the staggered seam clinches the side-walls forming interlock zones.
Advantageously, the crimp barrel is provided with at least one embossed area and at least one deepened area on inner and outer surface of the side-walls.
Advantageously, the embossed areas and the deepened areas extend up to the base of the crimp.
Advantageously, the crimp barrel is a F-crimp wire barrel.
Advantageously, a depth of the deepened area is 1/3 to 1/2 of side wall thickness.
In the aspect of the present disclosure, a method for producing a crimp for connecting wires comprising a step of bending a base of a crimp barrel around the wires such that at least two opposing side-walls extending from the base engage with one another along a staggered seam.
Advantageously, the ends of the side-walls have embossed and deepened areas on the outer surface of the crimp barrel such that the embossed area of the first side-wall engages with the deepened area of the second side-wall.
Advantageously, the deepened areas have interlock surfaces.
Advantageously, the staggered seam clinches the side-walls forming interlock zones.
Advantageously, the crimp barrel is provided with at least one embossed area and at least one deepened area on inner surface and outer surface of the side-walls.
Advantageously, the crimp barrel is a F-crimp wire barrel.
Advantageously, a depth of the deepened area is 1/3 to 1/2 of side wall thickness.
Additional benefits and advantages of the disclosed embodiments will become apparent from the specification and drawings. The benefits and/or advantages may be individually obtained by the various embodiments and features of the specification and drawings, which need not all be provided in order to obtain one or more of such benefits and/or advantages.
The invention is explained in greater detail below with reference to embodiments and the appended drawings. Elements or components which have an identical, univocal or similar

construction and/or function are referred to in various Figures of the drawings with the same reference numerals. In the detailed Figures of the drawings:
Fig. 1 is a schematic perspective view of an embodiment of a crimp connection according to the present disclosure;
Fig. 2 is schematic of a crimp connection in closed state where the ends of the flanks with embossed and deepened areas provide interlock surfaces;
Fig. 3 is a schematic of the crimp connection according to another embodiment of a crimp connection according to the present disclosure.
Prior to a description of embodiments of the present disclosure, underlying knowledge forming the basis of the present disclosure is described. Based on the foregoing consideration, the inventors have conceived of the following aspects of the present disclosure.
A crimp is provided for connecting wires comprising at least one crimp barrel, wherein the crimp barrel comprises at least one base and at least two opposing side walls extending from the base, wherein the side-walls are adapted for bending around
the wires such that ends of the opposing side-walls engage with one another along a staggered seam.
This makes it possible to improve seam locking against axial distortion of the flanks and to create additional clinching of the seam due to axial elongation of the crimp while compression at crimp forming.
More specific embodiments of the present disclosure are described below. Note, however, that an excessively detailed description may be omitted. For example, a detailed description of an already well-known matter and a repeated description of substantially identical components may be omitted. This is intended to avoid unnecessary redundancies of the following description and facilitate understanding of persons skilled in the art. It should be noted that the inventors provide the accompanying drawings and the following description so that persons skilled in the art can fully understand the present disclosure, and that the accompanying drawings and the following description are not intended to limit the subject matters recited in the claims. In the following description, identical or similar constituent elements are given the same reference numerals.
According to the general idea of the present disclosure a staggered seam of the engaged crimp side-walls is an element of a crimp connection. A crimp for connecting wires comprises

at least one crimp barrel, wherein the crimp barrel comprises at least one base and at least two opposing side walls extending from the base, wherein the side-walls are adapted for bending around the wires such that ends of the opposing side-walls engage with one another along a staggered seam in the crimped state.
Figure 1 shows a schematic representation of a crimp connection 10 in a crimped state. Side walls 4 are in a crimped state forming “a square meandering” or a “zig-zag” seam line. In Figure 1, the crimp connection is such that the staggered seam 1 of the crimp connection 10 increases the robustness with the thinner stock material.
In addition, it is advantageous if the crimp connection 10 is designed in such a way that the side-walls 4 of the crimp connection engaging to form a staggered seam 1 in the longitudinal direction have the “square-meandered” shaped seam line. The engagement elements effect a form-fit between the ends of the crimp side-walls 4 along the longitudinal seam. The ends of the crimp side-walls are rigidly connected to one another by the form-fit connection. The rigid connection of the ends of the crimp side-walls 4 increases the overall stability of the crimp connection and thus prevents a loss of crimp forces due to the forces and moments applied to the crimp connection.
As described above, a form-fit between the ends of the crimp side-walls 4 itself increases the overall stability of the crimped connection. In addition, it increases the resistance moment of the bent crimp flanks against bending.
As a further advantageous effect, the crimped connection can be designed in such a way that the staggered seam 1 in the longitudinal direction has a lateral offset at least in sections. The offset allows the material of the opposing sections of the crimping flanks to flow around one another during the crimping process and to provide a form fit.
Further, the above stated problem is solved in that the ends of the crimp flanks are brought into engagement with one another at a staggered seam. The ends of the crimp side-walls can no longer be displaced in the longitudinal direction due to the engagement with one another. Any loss of the crimping forces due to the relative movement of the crimping flanks in the longitudinal direction can thus be prevented.
FIG. 2 is a perspective view of another embodiment of a crimp segment 14. The crimp segment 14 includes a crimp barrel 20. The crimp barrel 20 includes a base 22 and opposing side walls 24 also referred to as crimp flanks that extend from the base 22. The base 22 and the side walls 24 define an opening 25 of the crimp barrel 20 that is configured to receive an end of a wire (not shown in the Figure) that may include one or more electrical conductors.

The crimp segment 14 may also be a part of a crimp that additionally comprises contact elements, a strain relief or the like.
The crimp barrel 20 is configured to be crimped around the end of the wire to mechanically and electrically connect the wire to a terminal. Optionally, the wire is an electrical wire and includes an electrical insulation layer extending around the electrical conductors along at least a portion of the length of the electrical conductors.
In the illustrated embodiment, the base 22 and the side walls 24 extend along and define the entirety of the length of the crimp barrel 20. The base 22 includes an interior surface 40, and each of the side walls 24 includes an interior surface 42. The interior surfaces 40 and 42 define boundaries of the opening 25 of the crimp barrel 20.
In addition, it is advantageous for the ends of the crimp flanks 24 to be clamped along the longitudinal seam 1. Clamping positions the crimping flanks along the longitudinal seam and crimping force losses due to an opening of the longitudinal seam are thus prevented.
The crimp segment 14 may be fabricated from any materials, such as, but not limited to, copper, a copper alloy, copper clad steel, aluminum, nickel, gold, silver, a metal alloy, and/or the like. One or more portions or all of the crimp segment 14 may fabricated from a base metal and/or metal alloy that is coated (e.g., plated and/or the like) with another material (e.g., another metal and/or metal alloy). For example, one or more portions or the entire crimp segment 14 may be fabricated from a copper base that is plated with nickel.
The electrical conductors may be fabricated from any materials, such as, but not limited to, aluminum, an aluminum alloy, copper, a copper alloy, copper clad steel, nickel, gold, silver, a metal alloy, and/or the like.
Fig. 2 shows further to the features of crimp segment 10 of Fig. 1 in a non-crimped state, the ends of the crimp side walls 24 have been embossed to form embossed regions 32 and deepened to form deepened regions 31 to provide interlock surfaces for additional clinching of the seam.
In Figure 2, the staggered seam 1 of Embodiment 1 gets reinforced by having embossed areas 32 and deepened areas 31 on the outer surface of the crimp flanks 24 which are extending upwards from the crimp barrel. The embossed and deepened areas 32, 31 on the two crimp side-walls also called flanks facing each other are such that, when the two flanks of the crimp barrel are engaged, the embossed area 32 of one of the crimp flanks 24 engages with the deepened area 31 of the opposing crimp flank 24.

The embossed and deepened areas 31, 32 of the crimp connection could be realized by various methods for example by milling, corrugation or deformation of the material.
In Figure 3, further to the features of Figures 1 and 2, the crimp barrel 20 has embossed and deepened areas 31, 32 on both sides of the crimp flanks. This further increase the interlock surfaces and thus enhances the staggered seam interlocking of the crimp flanks.
In another aspect, the inner surfaces of the side-walls of the crimp barrel may include at least one fixing zone 44, like sharp-edged grooves (for instance, serrations) which may ensure a stronger grip, if present. The crimp barrel may include aluminum, so that during the crimping of the connection region and the fixing device may ensure partial cold welding and consequently establish a good electrical connection.
A fixing zone 44 of the crimp barrel is preferably constructed as a 3D structure zone having at least one groove and/or rib, a grooved structure, a ripple structure, a corrugated structure or a serration, that is to say, a “tooth-like arrangement” having wide teeth which extend substantially in the transverse direction. In this instance, fixing zones 44 is constructed in a similar manner on the inner surface of the side-walls of the crimp barrel and as mirror images of each other around the longitudinal axis.
The embossed and deepened areas of the crimp connection of Figure 3 can be realized by various methods for example by pressing etc.
In order to contact an electrically conductive wire, the crimp is for example attached to non-insulated wire. The electrical insulation layer may be removed from at least a portion of ends of the electrical conductors for exposing the conductor ends. In some alternative embodiments, the electrical contact is another crimp barrel 20 that is configured to be crimped around the end of another electrical wire (not shown) to mechanically and electrically connect the other electrical wire to the terminal.
Accordingly, in some alternative embodiments, the terminal is configured to electrically connect the electrical wire to another electrical wire. In other words, the terminal may be used to splice the electrical wire to another wire in some alternative embodiments.
Optionally, the interior surfaces 40 and/or 42 include one or more serrations 44 for penetrating an oxide and/or other surface material (such as, but not limited to, residual wire extrusion enhancement materials, and/or the like) layer that has built up on the electrical conductors 30. The interior surfaces 40 and 42 may each be referred to herein as a “metallic surface” of the crimp barrel 20.

The crimp segment of the above embodiments is used for realizing the electrical and mechanical connections using a crimping device. The crimping device crimps a crimping segment to a wire. In an embodiment, the electrical wire has electrical conductors that are received in a crimp barrel. For example, an end segment of the wire has exposed conductors that are loaded into the crimp barrel. During a crimping operation, the barrel is crimped around the conductors forming a mechanical and electrical connection between the crimp segment and the electrical wire.
The crimping operation entails forming the crimp segment 10, 14 to mechanically hold the conductors and to provide an engagement between the conductors and the crimp segment 10, 14. Forming of the terminal may include bending arms or tabs around the wire conductors as in an open terminal (e.g., “F” type crimp) or compressing a closed barrel around the wire conductors as in a closed terminal (e.g., “O” type crimp). As the terminal is formed around the wires during the crimping action, the metal of the terminal and/or of the conductors within the terminal may be extruded. It is desirable to provide a secure mechanical connection and a good quality electrical connection between the terminal and the electrical wire. Using the embodiments of crimp tooling as disclosed herein creates a formed feature on the terminal that is formed during the crimping operation due to the extrusion of the metal(s). With this tooling, the formed feature can be formed on various types of terminals with varying terminal shapes and designs.
According to the preferred embodiments of this invention, the length of the side walls is such that when the sidewalls are engaged to form a staggered seam, the ends of the side walls do not hit the inner surface of the crimp.
A crimping device (not shown in the figure) may include an anvil and a crimp tooling member. The anvil has a top surface that receives the crimp segment thereon. The electrical conductors of the wire are received in the crimp barrel on the anvil. The crimp tooling member includes a forming profile that is selectively shaped to form or crimp the barrel around the conductors when the forming profile engages the crimp segment. The forming profile defines part of a crimp zone in which the crimp segment and wire are received during the crimping operation. The top surface of the anvil also defines a part of the crimp zone, as the terminal is crimped to the wire between the crimp tooling member and the anvil.
The crimp tooling member is movable towards and away from the anvil along a crimp stroke. The crimp stroke has an upward component away from the anvil and a downward component towards the anvil. The crimp tooling member moves bi-directionally, towards and away from the anvil, along a crimp axis. The crimp tooling member forms the terminal around the electrical conductors during the downward

component of the crimp stroke as the crimp tooling member moves towards the anvil. Although not shown, the crimp tooling member may be coupled to a mechanical actuator that propels the movement of the crimp tooling member along the crimp stroke. For example, the crimp tooling member may be coupled to a movable ram of an applicator or lead-maker machine. In addition, the applicator or the lead-maker machine may also include or be coupled to the anvil and the base support of the crimping device.
During a crimping operation, the crimp segment 14 is loaded onto the top surface of the anvil. The wire is moved in a loading direction towards the crimp zone such that the electrical conductors are received in the crimp barrel 20 between the two side-walls of the crimp barrel. As the crimp tooling member moves toward the anvil, the forming profile descends over the crimp barrel and engages the side-walls to bend or form the walls around the electrical conductors. More specifically, side tabs and the top-forming surface of the forming profile gradually bend the side-walls over a top of the electrical conductors as the crimp tooling member moves downward. The left arch of the forming profile is configured to engage and bend left side-walls of the crimp barrel, while the right arch is configured to engage and bend a right side-wall of the crimp barrel. At a bottom dead position of the crimp tooling member, which is the lowest position (or most proximate position to the base support) of the crimp tooling member during the crimp stroke, part of the forming profile may extend beyond the top surface of the anvil. The crimp segment is compressed between the forming profile and the anvil, which causes the side-walls of the crimp barrel to mechanically engage and electrically connect to the electrical conductors of the wire. High compressive forces cause metal-to-metal bonds between the side-walls and the conductors. One or more embodiments described herein is directed to the forming profile such that during the crimping operation as described herein a staggered seam is formed when the side-walls of the crimp barrel engage with each other.
Further the mechanics and the behavior of the crimp connection under external forces will be described.
There are two mechanisms for establishing and maintaining permanent contact in a crimp connection, namely cold welding and the generation of an appropriate residual force distribution. Both mechanisms contribute for creating a permanent connection and are independent of each other. During crimping two metal surfaces are brought under an applied force to sliding or wiping actions thus welding the metals in a cold
version also known as cold welding. Under an appropriate residual force distribution the contact interface will experience a positive force. During crimping, residual forces are

developed between the conductor and the crimp barrel as the crimp tooling is removed which is an indicative of different elastic recovery.
When the electrical conductor tends to the spring back more than the crimp barrel, the barrel exerts a compressive force on the conductor which maintains the integrity of the contact interface. The electrical and the mechanical performance of a crimped connection results from a controlled deformation of conductors and crimp barrel which produce micro cold welded junctions between the conductors and between conductors and the crimp barrel. These junctions are maintained by an appropriate residual stress distribution within the crimped connection which leads to residual forces which in turn maintain the stability of the junctions.
During the application of an external force (for example tensile force) on the crimp connection the interlocking between the crimps flanks could be misaligned, thus resulting in a poor crimp connection. Hence crimp connections with embossed areas 31, 32 that are tapering in an inward direction toward the staggered seam are provided in embodiments of the crimp connection of the present disclosure.
Such tapered embossed areas could be provided both inside or outside of the crimp flanks thereby ensuring that interlocking is maintained even when the tensile force applied at an angle not equal to the normal vector in the lateral direction of the outer surface of the crimp flank.
While the present disclosure has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from intent of the disclosure as defined by the appended claims. The exemplary embodiments should be considered in descriptive sense only and not for purposes of limitation. Therefore, the scope of the present disclosure is defined not by the above description of the invention but by the appended claims, and all differences within the scope will be construed as being included in the present invention.

Claims:
1. A crimp for connecting wires comprising at least one crimp barrel, wherein the crimp barrel comprises at least one base and at least two opposing side walls extending from the base, wherein the side-walls are adapted for bending around the wires such that ends of the opposing side-walls engage with one another along a staggered seam.
2. The crimp according to claim 1, wherein the ends of the opposing side-walls are provided with at least one embossed area and at least one deepened area on the outer surface of the crimp barrel such that the embossed area of a first side-wall engages with the deepened area of a second side-wall.
3. The crimp according to claim 2, wherein the deepened areas are provided with interlock surfaces.
4. The crimp according to any of claims 1 to 3, wherein the staggered seam clinches the side-walls forming interlock zones.
5. The crimp according to claim 1, wherein the crimp barrel is provided with at least one embossed area and at least one deepened area on an inner and a outer surface of the side-walls.
6. The crimp according to claim 2 or 5, wherein the embossed areas and the deepened areas extend up to the base of the crimp.
7. The crimp according to any one of the claim above, wherein the crimp barrel is a F-crimp wire barrel.
8. The crimp according to claim 2 or 5, wherein a depth of the deepened area is 1/3 to 1/2 of side wall thickness.
9. A method for producing a crimp for connecting wires comprising a step of bending a base of a crimp barrel around the wires such that at least two opposing side-walls extending from the base engage with one another along a staggered seam.
10. The method for producing the crimp according to claim 9, wherein the ends of the side-walls have embossed and deepened areas on the outer surface of the crimp barrel such that the embossed area of the first side-wall engages with the deepened area of the second side-wall.

11. The method for producing the crimp according to claim 10, wherein the deepened areas have interlock surfaces.
12. The method for producing the crimp according to claim 11, wherein the staggered seam clinches the side-walls forming interlock zones.
13. The method for producing the crimp according to claim 9, wherein the crimp barrel is provided with at least one embossed area and at least one deepened area on inner surface and outer surface of the side-walls.
14. The method of producing the crimp according to any of claims 9 to13, wherein the crimp barrel is a F-crimp wire barrel.
15. The crimp according to any one of claims 10 or 13, wherein a depth of the deepened area is 1/3 to 1/2 of side wall thickness.