Electrical contact element and contact arrangement

A contact arrangement comprises an electrical contact element including a plate member with a contact slot configured to receive an electrically insulated conductor. The plate member has first and second plate arms extending there from that delimit the contact slot. At least one retaining element extends from a plane of the plate member configured to secure the electrical contact element in a housing. The retaining element has first and second retaining surfaces arranged at a fixed angle to each other. The fixed angle is less than 180 degrees. A housing has a contact accommodating chamber that receives the electrical contact element. The contact accommodating chamber has first and second conductor receiving openings and a wall. The retaining element engaging the wall when the electrical contact element is positioned in the contact accommodating chamber.

FIELD OF THE INVENTION

The invention relates to an electrical contact element having a plate member with at least one retaining element extending from a plane of the plate member that is configured to secure the electrical contact element in a housing. The invention further relates to a contact arrangement containing the same.

BACKGROUND OF THE INVENTION

Electrical contact elements that are used for contacting an electrically insulated conductor are well known. For example, Tyco Electronics manufactures an electrical contact element known as MAG-MATE, which has a contact slot for contacting an electrically insulated conductor. When the electrically insulated conductor is inserted into the contact slot, the electrical insulation of the electrically insulated conductor is cut open by edges of the contact slot such that electrical contact is established between the electrically insulated conductor and the electrical contact element.

In order to ensure good electrical contact, the contact slot needs to have a width smaller than a diameter of the electrically insulated conductor after the insulation is removed. The electrical insulation can thereby be cut open when the electrically insulated conductor is inserted into the contact slot and direct contact between the electrical contact element and the electrically insulated conductor can be ensured. A disadvantage of this configuration, however, is that when the contact slot is expanded during insertion of the electrically insulated conductor, the geometry of the electrical contact element can be altered and/or compressive stresses can be created in the electrical contact element. If the electrical contact element has retaining elements with which the electrical contact element is secured inside a housing, there is therefore a danger that the engagement between the electrical contact element and the housing could be impaired through the compressive stresses and/or the alteration of the geometry of the electrical contact element.

A electrical contact element and a connector arrangement consisting of the electrical contact element and a housing is known from DE19743 328 A1. The electrical contact element has a substantially U-shaped insulation displacement region and a contacting region with two contacting arms, which are arranged with their edges positioned opposite each other. Each of the contact arms is constructed in two layers in a region of a contacting zone so that the edges of both layers contribute to a contacting process. The insulation displacement region comprises two insulation displacement terminals that are arranged parallel to each other and form the sides of the U-shaped insulation displacement region. The electrical contact element also has fastening devices for fastening the electrical contact element inside a contact receiving chamber of the housing. The fastening devices are arranged such that forces of the fastening devices on the housing and forces of the insulation displacement terminals on the housing run perpendicular to each other. The fastening devices are provided in a region of the insulation displacement terminals and just in front of the contacting region on both sides of the insulation displacement terminals and serve to fasten the electrical contact element inside the housing. The fastening devices are bent outwards by way of barbs from a plane of the insulation displacement terminals. To fasten the electrical contact element inside the housing, webs are provided on the housing into which the barbs of the electrical contact element engage when the electrical contact element is inserted into the contact receiving chamber of the housing.

BRIEF SUMMARY OF THE INVENTION

It is therefore an object of the invention to provide an improved electrical contact element with a contact slot, wherein a retaining function of the electrical contact element is less adversely affected by the insertion of the electrically insulated conductor.

This and other objects are achieved by an electrical contact element comprising a plate member with a contact slot configured to receive an electrically insulated conductor. The plate member has first and second plate arms extending there from that delimit the contact slot. At least one retaining element extends from a plane of the plate member configured to secure the electrical contact element in a housing. The retaining element has first and second retaining surfaces arranged at a fixed angle to each other. The fixed angle is less than 180 degrees.

This and other objects are further achieved by a contact arrangement comprising an electrical contact element including a plate member with a contact slot configured to receive an electrically insulated conductor. The plate member has first and second plate arms extending there from that delimit the contact slot. At least one retaining element extends from a plane of the plate member configured to secure the electrical contact element in a housing. The retaining element has first and second retaining surfaces arranged at a fixed angle to each other. The fixed angle is less than 180 degrees. A housing has a contact accommodating chamber that receives the electrical contact element. The contact accommodating chamber has first and second conductor receiving openings and a wall. The retaining element engaging the wall when the electrical contact element is positioned in the contact accommodating chamber.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1shows an electrical contact element1according to a first embodiment of the invention. The electrical contact element1may be formed, for example, by stamping a plate. As shown inFIG. 1, the electrical contact element1has a contact slot4opening downwards, which terminates at a substantially rounded opening5. First and second plate arms2,3are attached at a top of the contact slot4and extend on both sides thereof to form a plate member6. Side edges of the first and second plate arms2,3delimit the contact slot4. A retaining element7is bent outwards from a plane of the plate member6substantially above the opening5. The retaining element7is configured to retain the electrical contact element1when the first electrical contact element1is fastened inside a housing38(FIG. 4). The retaining element7may be, for example, stamped out of the plate member6such that an opening8is formed. The retaining element7may be formed, for example, as a tongue, a retaining lug, or a spike. Because the retaining element7is arranged above the contact slot4and projects from the plane of the plate member6, the form and position of the retaining element7is not changed when either an electrically insulated conductor18is inserted into the contact slot4causing the first and second plate arms2,3to deflect laterally or when electrical insulation47of the electrically insulated conductor18is cut open.

FIG. 2shows an electrical contact element9according to a second embodiment of the invention. The electrical contact element9may be formed, for example, by stamping a plate. As shown inFIG. 2, the electrical contact element9has a plate member6with a contact slot4opening downwards, which terminates at a substantially rounded opening5. Retaining elements10,11are arranged above the opening5in opposite edges of the plate member6. In the illustrated embodiment, the retaining elements10,11are arranged symmetrically about a longitudinal axis17of the contact slot4. Because of the positioning of the retaining elements10,11, an even distribution of the retaining forces is achieved when the electrical contact element9is inserted into a housing. The retaining elements10,11may be stamped and bent outwards from a plane of the plate member6. Alternatively, the retaining elements10,11may be worked out of the plate member6using a stamping process. The retaining elements10,11may be formed, for example, as tongues.

As shown inFIG. 3, during the stamping process, an embossment resulting from the stamping process projects outwards from the plane of the plate member6and an indentation or a stamped opening12is constructed in the plate member6. In the illustrated embodiment, the retaining element10was stamped out of the plate member6using a forming die to form an embossment having first and second retaining surfaces13,14arranged at a fixed angle of less than 180 degrees to each other. The first and second retaining surfaces13,14form an angled retaining lug. The first retaining surface13is aligned along a first axis15that extends parallel to the longitudinal axis17of the contact slot4, and the second retaining surface14is aligned along a second axis16that extends perpendicular to the longitudinal axis17of the contact slot4. The first and second retaining surfaces13,14are connected to each other via a connecting line in a connection region. The first and second retaining surfaces13,14extend from the surface of the plate member6and rise to a maximum height in the connecting region. An angle19between the first and second retaining surfaces13,14is preferably about90degrees. The first and second retaining surfaces13,14fix the electrical contact element9inside the housing such that movement perpendicular to the first axis15and the second axis16is prevented. Alternatively, the retaining elements10,11may be formed to have a simpler configuration, such as a spike stamped out of the plate member6or two spaced parts.

FIG. 4shows a contact arrangement consisting of the housing38provided with the electrical contact element1according to the first embodiment. The housing38has a contact accommodating chamber39. First and second conductor receiving openings40,41are provided on opposite sides of the contact accommodating chamber39. The electrically insulated conductor18is pushed through the first and a second conductor receiving openings40,41. The electrical contact element1is then plugged into the contact accommodating chamber39from above so that the electrically insulated conductor18is inserted into the contact slot4and the electrical insulation47of the electrically insulated conductor18is cut open by the side edges of the contact slot4. A mechanical and electrically conductive connection is thereby established between the electrical contact element1and the electrically insulated conductor18.

The retaining element7engages a wall of the contact accommodating chamber39when the electrical contact element1is inserted therein. For example, the retaining element7may penetrate the material of the wall when the electrical contact element1is inserted in the contact accommodating chamber39. The housing38is preferably made from a flexible plastic material, so that the retaining element7can effectively penetrate the plastic material and establish an interlocking connection therewith. The retaining element is thereby frictionally and/or positively secured in the housing38. Additionally, the wall can be deformed or cut through in the process to accommodate the retaining element7. Depending on the hardness of the material of the wall, a clamping retention can also be established by the retaining element7whereby the retaining element7does not penetrate the wall. The retaining element7thereby prevents movement of the electrical contact element1with respect to the housing38so that electrical contact between the electrically insulated conductor18and the electrical contact element1is ensured. The electrical contact element1can also be further connected to another electrical conductor via a plug-in or solder connection so that an electrical connection is established between the electrically insulated conductor18and the other conductor.

The electrical contact element9according to the second embodiment can be inserted into the contact accommodating chamber39of the housing38in the same manner as the electrical contact element1according to the first embodiment. The retaining elements10,11of the electrical contact element9similarly engage the wall of the housing38when the electrical contact element9is inserted into the contact accommodating chamber39. The retaining elements10,11secure the electrical contact element9inside the housing38in both the insertion direction of the electrical contact element9into the contact accommodating chamber39and perpendicular to the insertion direction of the electrical contact element9into the contact accommodating chamber39.

FIG. 5shows an electrical contact element20according to a third embodiment of the invention. The third electrical contact element20has first and second plates members21,22arranged substantially parallel to each other. The first plate member21has a contact slot27, which is delimited by first and second plate arms23,24. The contact slot27terminates at a substantially rounded opening46. The second plate member22has a contact slot28, which is delimited by third and fourth plate arms25,26. The contact slot28is arranged substantially parallel to the contact slot27. The contact slot27terminates at a substantially rounded opening. Depending on the embodiment, the contact slot28may be formed identical to the contact slot27or may be formed to have a larger slot aperture so that an electrically insulated conductor18can be guided therein without damaging electrical insulation47of the electrically insulated conductor18.

The first plate arm23is connected to the fourth plate arm26via a first bent portion31. In the illustrated embodiment, the first plate arm23, the first bent portion31, and the fourth plate arm26are constructed in one piece. The second plate arm24is connected to the third plate arm25via a second bent portion32. In the illustrated embodiment, the second plate arm24, the second bent portion32, and the third plate arm25are constructed in one piece. The first and second bent portions31,32are preferably constructed in the form of two partial portions, which are connected to each other frictionally or in an interlocking manner. Insertion openings29,30are formed between the first and second bent portions31,32. The insertion openings29,30are constructed so as to converge towards the contact slots27,28, respectively.

The first and second plate members21,22are connected in an upper plate region via first and second connecting strips33,34. The first and second connecting strips33,34extend laterally outwards from the upper plate regions of the first and second plate members21,22. The first and second connecting strips33,34each have a lower edge region that can serve as a stop element37. A spring contact35of substantially U-shaped construction is attached, pointing upwards to the first plate member21. A free end of the spring contact35is bent backwards, towards an upper region of the second plate member22and rests on a supporting spring portion36. The supporting spring portion36extends upwards out of the upper plate region of the second plate member22and is bent backwards and inwards towards the first plate member21. The spring contact35includes a slot defining two substantially U-shaped members formed side by side.

The first plate member21has retaining elements10,11formed therein. The retaining elements10,11are arranged symmetrically about a longitudinal axis of the contact slot27. The retaining elements10,11are constructed in the form of embossments. At least one of the retaining elements10,11has retaining surfaces13,14, which are arranged at a fixed angle19to each other, for example, 90 degrees, as shown inFIG. 3. Alternatively, the retaining elements10,11are arranged opposite the longitudinal axis of the contact slot27such that the retaining surfaces14of the retaining elements10,11are arranged on the longitudinal axis of the contact slot27and the retaining surfaces13of the retaining elements10,11are arranged parallel to each other. Openings12, which are preferably substantially triangular in shape, are introduced via a stamping process into the upper plate region of the first plate member21adjacent to the retaining elements10,11. The torsional strength of the plate region is increased by the stamping of the retaining elements10,11. The triangular shape of the opening12additionally increases the rigidity of the plate region.

As shown inFIG. 6-7, the second plate member22has retaining elements10,11formed therein. Because the retaining elements10,11of the second plate member22are constructed identically to the retaining elements10,11of the first plate member21and are arranged symmetrically thereto further description thereof has been omitted.

FIG. 6shows a contact arrangement consisting of a housing43provided with the electrical contact element20according to the third embodiment. The housing38has a contact accommodating chamber44that receives the electrical contact element20. The contact accommodating chamber44is open in an upper region of the housing42and has substantially the same cross-section as the electrical contact element20. The electrically insulated conductor18is guided through the second housing43via first and second conductor receiving openings40,41. The electrically insulated conductor18rests on supporting surfaces of the housing43in regions of the first and second conductor receiving openings40,41. The electrical contact element20is then pushed over the electrically insulated conductor18so that the electrically insulated conductor18is introduced into the contact slots27,28. During this process, the electrical insulation47of the electrically insulated conductor18is cut open by the side edges of the contact slot27so that a mechanical and electrically conductive connection is established between the electrical contact element20and the electrically insulated conductor18. At least the contact slot27expands when the conductor18is inserted for good electrical contact.

The electrical contact element20is simultaneously secured to walls of the housing43via the retaining elements10,11of the first and second plate members21,22. Due to the shape and position of the retaining elements10,11on the first and second plate members21,22, the fastening of the electrical contact element20to the housing43is not adversely affected by the expansion of the contact slot27or the introduction of bias into the region of the contact slot27.

As shown inFIG. 7, the stop elements37of the first and second connecting strips33,34abut support edges42in the housing43when the electrical contact element20is inserted therein. A maximum insertion depth of the electrical contact element20is thereby fixed. By restricting the maximum insertion depth, the electrically insulated conductor18is prevented from being cut too deeply by the contact slot27. Damage to the electrically insulated conductor18and excessive expansion or excessive bias into the contact slot27of the first plate member21is thus avoided.