Patent Application
20160380375
This application is based upon and claims the benefit of prior German Patent Application No. 10 2015 110 226.9, filed on Jun. 25, 2015, the entire contents of which are incorporated herein by reference.
The present disclosure relates to an electrical contact having a fixed and a movable contact part in a metal housing, for which a cleaning system is being introduced.
DE 10 2015 104 377 discloses an electrical contact in which a fixed and a movable contact part can be connected to each other via a large contact surface. The two contact parts are disposed within a metal housing and pressed against each other by way of a leaf spring. It is furthermore disclosed how the two contact parts can be locked with respect to each other by way of a metal pin. However, the contact includes a variety of drawbacks. For example, dirt particles, which are introduced via the contact surfaces of the contact parts or develop during operation of the contact, compromise the contact quality over time.
DE 4 220 716 A1 and DE 10 2014 115 745 A1 disclose sealing lips, which may also have a cleaning effect. However, while these lips keep a cable insulation or insertion socket clean, they do not clean the contact surface.
Embodiments of the present disclosure provide a cleaning system for an electrical contact.
The electrical contact according to the present disclosure contains a metal housing and a fixed contact part, which is attached to the metal housing and has a contact surface, which during the attachment is located within the metal housing, and a contact tab located outside the metal housing. The electrical contact furthermore contains a movable contact part, which can be inserted into the metal housing and thus forms an electrical contact together with the contact surface of the fixed contact part. The cleaning system is introduced in that a surface of the fixed or movable contact part which establishes the electrical contact forms a profile having low-profile and high-profile portions. Scraping edges are disposed between the low-profile and high-profile portions. The scraping edges are angled less than 90° with respect to an insertion direction of the movable contact part and define a profile formed of rhombi.
In embodiments of the present disclosure, during the first insertion of the movable contact part, dirt particles stemming from the production of the contact part or the transport are removed, or at least the number of dirt particles is reduced. In this way, the electrical contact may have a cleaned contact and a lower contact resistance starting with the first use. This may be useful for high-current contacts.
In embodiments of the present disclosure, the rhombic shape in the profile does not significantly increase a required insertion force for the movable contact part and facilitates the removal of the dirt particles.
In embodiments of the present disclosure, a second dirt reservoir, which can accommodate a large number of dirt particles, is formed between the low-profile and high-profile portions of the surface. The second dirt reservoir can have a width of 0.2 to 1 mm, and preferably approximately 0.5 mm, and a depth of 0.3 to 1.2 mm, and preferably approximately 0.8 mm, for this purpose. This profile may simplify the manufacturing process and may accommodate any accumulating larger dirt particles without impairing the contact surface.
In embodiments of the present disclosure, the ratio of the required insertion force to the removal of dirt particles is optimal at an angle of 15 to 45°, and in particular at an angle of 30 to 40°, of the scraping edges relative to the insertion direction.
According to an embodiment of the present disclosure, the profile includes a plurality of rhombi, wherein the rhombi have a larger length than width in the insertion direction. This may also ensure that a large number of scraping edges is available for cleaning.
In embodiments of the present disclosure, the second dirt reservoir is formed by multiple gaps, which divide the profile in a rectilinear manner and have sharp edges with respect to the contact surface. As a result of the sharp-edged design, it is possible to easily separate oxide particles and surface impurities.
In embodiments of the present disclosure, the profile is disposed on the contact surface of the fixed contact part. When installed, the fixed contact part is typically disposed beneath the movable contact part, so that the dirt particles cannot fall out of the dirt reservoir and onto the contact surface.
In embodiments of the present disclosure, chamfers on narrow sides and deburred edges on broad sides may be provided as insertion aids within the profile. The production may be cost-effective when the profile is created by way of embossing and stamping. If the low-profile portions of the profile have a smaller surface than the high-profile portions, the use of the cleaning system reduces the contact surface only marginally.
In embodiments of the present disclosure, a further cleaning system is introduced in that at least one further scraping edge is provided near the contact surface, the movable contact part making contact with this scraping edge during insertion. A surface of the movable contact part which later establishes the contact thus passes over the scraping edge and possible dirt particles are removed.
According to an embodiment of the present disclosure, a dirt reservoir is provided adjoining the scraping edge. During a relative movement between the fixed and movable contact parts, the aforementioned dirt particles fall into the dirt reservoir. This may ensure that the dirt particles do not contaminate the contact surface again after scraping.
According to an embodiment of the present disclosure, a cleaning lip made of a plastic material is attached as the scraping edge. The cleaning lip is attached to an opening of a connector housing surrounding the metal housing. The cleaning lip thus makes contact with a surface of the movable contact part every time the movable contact part is inserted into the metal or connector housing and scrapes off the dirt particle. The dirt particles are then already scraped off the first time they could find their way into the connector housing.
According to an embodiment of the present disclosure, the cleaning lip is made of a softer material compared to the connector housing. For example, if the connector housing is made of a thermoplastic, then the material of the cleaning lip is either a soft thermoplastic or a hard elastomer. Furthermore, the upper face of the cleaning lip may be chamfered, for example downwardly sloping into the interior of the connector housing. Due to this relatively sharp edge, it is possible, using little friction, to scrape off the majority of the dirt particles and not allow them to penetrate into the housing in the first place. Should dirt particles still find their way into the interior of the connector housing via the cleaning lip, they will slide via the downwardly sloping surface into a first dirt reservoir, which may be disposed between the end face of the fixed contact part and the connector housing. This is thus located beneath the movable contact part and next to the contact surface and will no longer reach the contact surface. The cleaning lip may be disposed perpendicularly to the insertion direction.
According to an embodiment of the present disclosure, the cleaning lip has an opening that does not impair the scraping edge, but makes the metal housing accessible from outside the connector housing, even in the installed state. This may be advantageous when the metal housing must be unlocked from the connector housing by way of pliers or a screwdriver.
According to an embodiment of the present disclosure, the metal housing has a latching device on the upper and lower faces, which is used for securing within the connector housing. The metal housing is thus non-slidably disposed in the connector housing, even though forces act on the metal housing as a result of the insertion of the movable contact part in the insertion direction.
According to an embodiment of the present disclosure, the metal housing is box-shaped and has cut-outs on the lateral walls used to attach the fixed contact part near the lower face of the metal housing. Ultimately, the fixed contact part is fixed in the metal housing in these cut-outs, wherein the fixed contact part comprises catch lugs on the side regions thereof for this purpose.
According to an embodiment of the present disclosure, so as to generate a pressing force between the contact parts, the metal housing contains a leaf spring in the interior. During insertion of the movable contact part, the leaf spring is slightly tensioned. The pressing force and locking may include an additional locking mechanism, for example, as described in DE 10 1015 104 377. The metal housing comprises a convex region toward the housing interior for this purpose so as to establish the starting and end positions of a movable locking pin. In the end position, the locking pin locks the leaf spring in a pressure position with respect to the contact parts.
According to an embodiment of the present disclosure, the material can be selected separately for each of the design components. The contact parts are made of copper, for example, and may optionally be coated with silver to further decrease the contact resistance. Independently of the selection of the electrical contact elements, the metal housing may be made of steel to ensure sufficient mechanical strength.
The described properties of the present disclosure and the manner in which these are achieved will be described in more detail based on the following detailed description. The foregoing general description and the following detailed description are exemplary and explanatory only, and are not restrictive of embodiments consistent with the present disclosure. Further, the accompanying drawings illustrate embodiments of the present disclosure, and together with the description, serve to explain principles of the present disclosure.
In view of the relatively large contact surface 4, dirt particles between the contact parts 2, 6 would adversely affect the contact quality. The dirt particles would also be very difficult to remove from the contact surface during operation.
The metal housing 1 comprises two latching devices 19, on the top and bottom faces of the metal housing 1. The metal housing 1 additionally includes a concave portion 11, which protrudes into the housing interior. A locking pin 17, which can be displaced along the axis of the high-current contact, is visible in a further elongated hole-shaped opening in the side walls of the metal housing 1. The pin may reach a starting position 15 and an end position 16. The locking pin assumes the starting position 15 when the movable contact part is being inserted. Once the movable contact part 6 has been completely inserted, the locking pin 17 is moved into the end position 16 and pushes the leaf spring (which is not visible here and shown in
In
The cleaning lip 8 and the connector housing 9 may be produced as a two-component injection-molded part. Alternatively, the cleaning lip 8 may also be glued or clamped into the connector housing 9.
The fixed contact part 2 according to
The profile 3 generated by way of embossing and stamping on the surface of the fixed contact part 2 has a rhombic shape, comprising a plurality of scraping edges 8′ identified by way of example in
These dirt particles fall into dirt reservoirs 7′ formed between the scraping edges 8′. The dirt reservoirs 7′ are thus located between the low-profile and high-profile portions of the profile 3.
The dimensions of the profile 3 are more clearly apparent from
According to
Gaps 33, which form the low-profile portions of the profile 3, and thus also the dirt reservoir 7′, are disposed between the rhombi 30. The gaps 33 are disposed at an angle of 35° relative to the insertion direction R. The gaps 33 are rectilinear to ensure good dirt particle transport and have a width bs of 0.5 mm and a depth of 0.8 mm.
While the present disclosure is illustrated and described in detail according to the above embodiments, the present disclosure is not limited to these embodiments and additional embodiments may be implemented. Further, other embodiments and various modifications will be apparent to those skilled in the art from consideration of the specification and practice of one or more embodiments disclosed herein, without departing from the scope of the present disclosure.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2015 110 226.9 | Jun 2015 | DE | national |
