Crimp Indentor, Crimping Tool and Method of Producing a Crimp Indentor

A crimp indentor for producing a crimp connection between an electrical conductor and a contact comprises a base and a machining portion connected to the base. The machining portion has a ceramic surface on at least a part of the machining portion. The machining portion is configured to transmit crimping forces to the contact while producing the crimp connection.

FIELD OF THE INVENTION

The present invention relates to a crimp indentor and, more particularly, to a crimp indentor for producing a crimp connection between an electrical conductor and a contact.

BACKGROUND

During crimping of contacts to electrical conductors/electric cables, a piece of metal is mechanically deformed to produce an electrical and/or mechanical connection. Crimp connections are used extensively to attach electrical contacts and connectors to cables. It is common for metal lugs of a contact to be deformed in a pressing device such that they enclose and firmly clamp an insulation casing or a stripped conductor.

For the mechanical production of such crimp connections, crimping devices are used in which a portion of a cable and corresponding crimping lugs are positioned between a crimp indentor and a crimp anvil. Bringing the crimp indentor and the crimp anvil together deforms the crimping lugs around the cable and crimps the lugs to the cable, forming an electrical connection between the contact and the conductor. At the end of the crimping operation, the crimping lug has an outer contour in the crimping region in the form of the contour of the crimp indentor.

Known crimp indentors have a base on which a machining portion of the crimp indentor is fitted and a corresponding crimping tool. The machining portion contacts the crimping tool and forms the crimp connection. To produce a precise and firm crimp connection, such crimp indentors must meet stringent dimensional requirements and must be capable of absorbing considerable forces in the respective machining ranges during the crimping operation. Crimp indentors consequently are commonly produced from high-alloy, abrasion-resistant and wear-resistant tool steel. Although such crimp indentors exhibit good properties during use, they are nevertheless relatively complex and expensive to produce since the crimp indentors have to be subsequently hardened, polished and chrome-plated, and reworked following the chrome-plating operation. Such highly precise machining is time-consuming and costly. Crimp indentors cannot currently be produced in a fully automated and efficient manner.

SUMMARY

A crimp indentor for producing a crimp connection between an electrical conductor and a contact comprises a base and a machining portion connected to the base. The machining portion has a ceramic surface on at least a part of the machining portion. The machining portion is configured to transmit crimping forces to the contact while producing the crimp connection.

DETAILED DESCRIPTION OF THE EMBODIMENT(S)

A crimp indentor100according to an embodiment is shown inFIGS. 1 and 2. The crimp indentor100is used to produce a crimp connection between an electrical conductor and a contact. The crimp indentor100includes a base110and a machining portion120. The crimp indentor100is cut out of a crimp indentor blank; the crimp indentor blank may be formed of various material in various embodiments.

The crimp indentor100is fixed and retained on a crimping tool head at the base110of the crimp indentor100. The machining portion120, shown inFIG. 2, is configured to transmit crimping forces to the contact during the production of the crimp connection. At least a portion of the machining portion120has a ceramic surface. The ceramic surface is disposed on the machining portion120in such a manner that the crimping forces occurring during the production of the crimp connection are transmitted to the contact via the ceramic surface.

The machining portion120or the ceramic surface of the machining portion120can be formed with a plurality of different indentor contours in various embodiments. The indentor contour has a three-dimensionally curved surface122, as shown inFIGS. 1 and 2. In the embodiment shown inFIG. 2, the curved surface122is shaped to produce a B-crimp connection.

To form a crimp connection, an electrical conductor is disposed between the machining portion120of the crimp indentor100and a crimp anvil. A contact is positioned on the electrical conductor. The crimp indentor100and the crimp anvil are then brought together; the crimp anvil is configured to push the electrical conductor and the contact against the crimp indentor100and generate crimping forces between the crimp indentor100and the contact. The crimping forces plastically deform the contact and the electrical conductor is thereby surrounded by the contact. Between the crimp anvil and the three dimensionally curved surface122of the indentor contour, the contact is pushed together in order to produce a reliable mechanical and electrical contact around the electrical conductor.

In the embodiment shown inFIGS. 1 and 2, the ceramic surface has been applied to the machining portion120in the form of a coating130. In a further embodiment, the coating130is a sintered coating130.

A crimp indentor100according to another embodiment of the invention is shown inFIGS. 3 and 4. In the embodiment shown inFIGS. 3 and 4, the machining portion120has an insert140which is connected to the machining portion120of the crimp indentor100. The insert140consists of a ceramic material and the ceramic surface of the machining portion120is an outer surface of the insert140in this embodiment.

A crimp indentor100according to another embodiment of the invention is shown inFIG. 5. In the embodiment shown inFIG. 5, the base110and the machining portion120are monolithically formed as a single-piece crimp indentor100. The single-piece crimp indentor100consists of a ceramic material and is cut from a ceramic blank.

The crimp indentors100must have a sufficient strength and hardness to allow them to maintain precise dimensions even following a large number of crimp connections carried out under high levels of force. A material and finish of the machining portion120is important because frictional forces between the contact and the crimp indentor100should be minimized. Accordingly, a smooth surface finish of the ceramic surface results in a reduction in the co-efficient of friction and thus in a higher quality of the crimp connection, without any need for the use of additional lubricants. Using the ceramic surface results in the crimp indentor100being burr-free in the machining portion120. It is thus possible to process even difficult-to-crimp materials, for example stainless steel, and to achieve a longer service life for the crimp indentor100without the need for additional plating on the machining portion120. Further, for a machining portion120with a ceramic surface or a single-piece crimp indentor100made of ceramic material, fully automated production is possible which is more cost-effective and provides higher quality than previous production methods.