This application is the national stage application of PCT/EP2018/073638, filed Sep. 3, 2018, which claims priority to EP 17192169.5, dated Sep. 20, 2017.
The invention relates to an electrical connector for receiving at least one electrical conductor. For connection purposes, a bus bar and at least one clamp are provided. The clamp comprises a spring arm being moveable relative to the bus bar. The spring arm can be pre-loaded towards the bus bar so that an electrical conductor that is inserted into a gap between the bus bar and the spring arm can be mechanically secured, i.e., clamped and thereby connected to the bus bar by means of the spring arm. For connecting two or more electrical conductors by means of the connector, one or more clamps can be used, each clamp securing one or more of the conductors to the bus bar, thereby electrically connecting the conductors with each other. As the skilled person will understand, the clamp itself can participate in electrically connecting the conductors.
A general problem of the connector sketched above lies in the arrangement of the at least one clamp relative to the bus bar. Since these components need to cooperate with each other in order to safely secure an electrical conductor to the bus bar it is important to make sure that a suitable relationship between the components is maintained during operation, in particular under all circumstances. For example, the position of the clamp relative to the bus bar should not change regardless whether a conductor is connected or not. The position should also not change due to thermal and other mechanical factors. This restriction is a general challenge, and in particular when the connector should be compatible for various types of conductors that have different diameters.
When no conductor is connected, the spring arm usually directly cooperates with the bus bar, wherein the free end of the spring bar rests firmly on the bus bar. For connecting a conductor, it is necessary to lift the spring arm against a restoring force so that the conductor can be inserted into the clamp. Sometimes it is sufficient to push an end section of the conductor against the spring arm, wherein the spring arm is displaced in response and the necessary gap to insert the conductor into the clamp is formed. However, this is not always possible. Especially light flexible or twisted conductors usually cannot be inserted into the clamp and exert the force necessary to displace the spring arm. This means that the user of the connector needs to manually position the spring arm at some distance away from the bus bar, such that a suitable gap between the spring arm and the bus bar is formed. Then the electrical conductor can be inserted into the clamp. Afterwards, the spring arm can be released, so that the spring arm secures the conductor on the bus bar.
The connector can comprise a housing with at least one opening for inserting an electrical conductor, in particular an end section of an electrical conductor, into the housing. The clamp and the bus bar can be arranged inside the housing. In order to fulfil the above mentioned requirement of maintaining a predefined relationship between the clamp and the bus bar, i.e., the position of the clamp relative to the bus bar, the clamp and the bus bar are often secured inside the housing, wherein the bus bar and/or the clamp are mechanically connected to the housing. This mechanical connection is often problematic since mechanical stress can be exerted on the housing, in particular when the spring arm of the clamp is moved. Undesired deformation processes of the housing can result from mechanical stress exerted on the housing. Consequently, the position of the clamp and/or the bus bar can change and the predefined relationship between the bus bar and the clamp be lost. Moreover, when the housing is formed from a plastic material, the risk of deformation processes is not only present because of mechanical stress exerted on the housing, but also because of thermal influences. As the skilled person will understand, this is undesired because an electrical conductor secured in the connector can be released and disconnected unintentionally during operation of the connector, thus leading to unsafe electrical conditions (e.g., malfunction, short circuit).
An example embodiment of an electrical connector includes a bus bar and at least one clamp, wherein the at least one clamp comprises a spring arm moveable relative to the bus bar. The spring arm cooperates with the bus bar to secure an electrical conductor to the bus bar when the spring arm is in a connecting position, wherein the clamp is directly mounted to the bus bar. In this way, a predefined relationship between the clamp and the bus bar is maintained and no external support elements are necessary. The clamp and the bus bar can thus be accommodated in a housing without substantially exerting mechanical stress on the housing, in particular when the spring arm is deflected against a restoring force.
The term “directly mounted” means that at least a mechanical connection is formed without any intermediate parts such as adaptors which are prone to negatively influence the positional relationship between the bus bar and the clamp. In particular, the clamp is mechanically connected to the bus bar by means of an integral section of the clamp.
A direct mounting can also have advantages in electrical terms since the spring arm can be electrically connected to the bus bar by means of the direct mechanical mounting. In cases where a direct electrical connection between a conductor and the bus bar is lost, the spring arm can establish the electrical connection between the conductor and the bus bar. For this reason the clamp and the bus bar are preferably formed from an electrically conducting material, i.e. a metal. They can consist only of a metal. The bus bar preferably comprises copper. The clamp preferably comprises a steel, in particular a stainless steel.
The connecting position of the spring arm comprises any position in which the spring arm cooperates with the bus bar. The spring arm can either directly cooperate the bus bar, which is usually the case when no conductor is inserted into the clamp. However, the spring arm can also indirectly cooperate with the bus bar, in particular when a conductor is clamped between the spring arm and the bus bar, thereby securing the conductor to the bus bar. In contrast, a disconnecting position is a position in which the spring arm is held at a distance away from the bus bar without cooperating with a conductor.
According to one embodiment, the at least one clamp is latched to the bus bar. This can be accomplished by means of a snap-fit connection. For example the clamp and/or the bus bar can comprise one or more locking members for latching the clamp to the bus bar. A locking member of the clamp can be formed by a projection which engages with the bus bar, in particular behind the bus bar.
According to another embodiment, the bus bar is caught and/or clamped in at least one integral mounting section of the at least one clamp. The mounting section can be a cage portion being configured to receive the bus bar and thereby mount the clamp to the bus bar. In the mounted condition, the bus bar can be caught in the cage portion. Furthermore, the bus bar can have no support of a housing of the connector.
The at least one mounting section is formed by a support arm and a locking arm, wherein the bus bar extends between the support arm and the locking arm. In this way, the clamp grasps the bus bar. The spring arm is preferably arranged above the mounting section so that the spring arm can exert a force on the bus bar against the support arm of the mounting section when the spring arm is in the connecting position.
According to another embodiment, the at least one clamp comprises two mounting sections arranged on two opposite sides of the spring arm. The mounting of the clamp is thus mechanically very stable with respect to the spring arm, wherein any forces exerted by the clamp on the bus bar and vice versa are transmitted at two distant points around the spring arm. This is especially useful for maintaining a predefined relationship between the bus bar and the spring arm.
The bus bar can comprise at least one outer recess defining a predetermined position at which the at least one clamp is mounted to the bus bar. The clamp can thus only be secured at a predefined position which simplifies mounting the clamp to the bus bar (poka-yoke principle). If more than one clamp is mounted to the bus bar, a single recess can receive portions of two adjacent clamps. The number of necessary recesses for determining the mounting positions can thus be kept low, wherein stability of the bus bar is not substantially sacrificed and production resources are saved.
The bus bar can comprise at least one ramp section associated with a free end of the spring arm, wherein the ramp section forms a contact portion for an electrical conductor. The spring arm can comprise a free end which is bent towards the bus bar, and in particular towards the ramp section of the bus bar. Alternatively or additionally, the free end of the spring arm can comprise a contact edge facing the bus bar, and preferably, the ramp section of the bus bar.
According to another embodiment, the spring arm comprises a base portion which is integrally connected to a frame portion of the at least one clamp, and wherein the spring arm further comprises an extension portion which is integrally connected to the frame portion opposite from the base portion. The extension arm can act as a stabilizer for the clamp, in particular when the spring arm is moved from the connecting position towards a disconnecting position in which the spring arm exerts a greater force onto the frame portion. The extension arm can also define a maximum distance the spring arm can be moved away from the bus bar. This can ensure that the spring arm is not deflected beyond its elastic limit. The extension arm can also conduct excess forces to a housing of the connector during spring arm movement, thereby acting as a support arm for the clamp. The spring arm and/or the base portion can be resilient. The base portion can comprise a curved section.
According to another embodiment, the bus bar is at least partially flush with the at least one clamp. This allows for a very compact design of the connector and simplifies assembly of the connector.
According to another embodiment, the at least one clamp is mounted or mountable to the bus bar in a first direction, wherein the spring arm exerts a force on the bus bar in a second direction when the spring arm is in the connecting position, and wherein the first and second directions are substantially the same or substantially opposite. In the latter case, it is effectively impossible that the bus bar is dismounted due to the spring arm exerting a force onto the bus bar. In the case that the first and second directions are substantially the same, mounting of the clamp can be simpler, for example, when the spring arm of the clamp is displaced during mounting in response to an engagement with the bus bar. In any case, during assembly of the connector the spring arm can be lifted when the clamp is mounted to the bus bar. This can simplify the mounting as such and avoids any damage of the bus bar caused by the spring arm, in particular when the free end of the spring arm comprises a sharp edge.
The bus bar comprises at least one ramp section associated with a free end of the spring arm, wherein the ramp section forms a contact portion for an electrical conductor, and wherein the ramp section is inclined in the second direction in which the spring arm can exert a force on the bus bar.
The bus bar and/or the at least one clamp can have an at least substantially rectangular outer shape. This can simplify an assembly of the connector and is advantageous for arranging the bus bar and/or the clamp inside a housing of the connector.
The connector comprises a housing, wherein the bus bar and the clamp are arranged inside the housing. The connector can comprise more than one clamp mounted to the bus bar, wherein each clamp can define a connection terminal for an electrical conductor. The clamps can be mounted adjacent to each other. It is also possible that the connector comprises more than one bus bar, wherein clamps associated with a defined electrical potential are mounted to corresponding bus bars.
The connector is configured to connect all types of electrical conductors, i.e., rigid cables, twisted cables, stranded cables and stranded flexible cables, wherein the cross section area of the cables can be for example between 0.13 and 4 mm2.
The invention is described further in the following by means of exemplary embodiments shown in the enclosed drawings in which
In the following, identical or similar features will be identified by the same reference signs.
An electrical connector 10 having three connection terminals 12 is shown in
For each terminal 12, an associated slider 18 extends into the outer housing element 16. Each slider 18 is moveable independently from each other relative to the outer housing element 16 along a second axis B between a closed position and an open position, as will be explained further.
The clamp 24 comprises a spring arm 28 moveable along a first axis A between a connecting position and a disconnecting position. In
The spring arm 28 preferably comprises a curved and resilient base portion 32 which is integrally connected to a frame portion 34 that is substantially U-shaped. The spring arm 28 preferably further comprises an extension portion 36 which is integrally connected to the frame portion 34 opposite from the base portion 32. The spring arm 28 preferably further comprises a contact edge 37 extending perpendicular to the first axis A.
The clamp 24 preferably comprises two integral mounting sections 38, 38′ arranged on two opposite sides of the spring arm 28. In the embodiment of
Starting from the situation shown in
The first axis A and the second axis B are preferably perpendicular to each other when the clamp 24 is mounted to the bus bar 22. The clamp 24 is mounted to the bus bar 22 in a first direction dl preferably substantially parallel to the second axis B, wherein the spring arm 28 can exert a force on the bus bar 22 in the first direction dl when the spring arm 28 is in the connecting position (
Coming back to
The openings 54 are circular and are easily visible for a user due to the substantially circular shape of the adjacent portion of the outer housing element 16, i.e. a portion of the outer housing element 16 has a shape that corresponds to the shape of the openings 54 and the circular cross-section of the conductor 14, 14′ to be inserted. The openings 54 can thus provide good mechanical support for the inserted conductor 14, 14′. Furthermore, the number of available terminals 12 can intuitively be recognized by a user.
Each opening 54 communicates with a circular channel 114 which forms a guiding channel for the conductor 14 during insertion (cf.
As shown in
Further details of the bus bar 22 are described with reference to
The spring arm 28 cooperates with the bus bar 22 when the spring arm 28 is in the connecting position, as shown in
In
In order to move the spring arm 28 from the connecting position into the disconnecting position, the slider 18 is moved from the closed position into the open position in which the slider 18 preferably protrudes out of the outer housing element 16 as shown in
The sliding guides 74 are preferably formed at two opposite side arms 76, 76′ of the slider 18, wherein the side arms 76, 76′ preferably extend parallel to the second axis B and grasp the clamp 24, as shown, e.g., in
The sliding guide 74 cooperates with a preferably convex support surface 82 of the spring arm 28 (
As can be seen, e.g., in
For securing the slider 18 in the closed position, the slider 18 preferably comprises V-shaped recesses 86 which engage with preferably wedge-shaped projections 88 formed at the inner housing element 26 when the slider 18 is in the closed position (
The connector 10 further comprises second locking members for securing the slider 18 in the open position. The second locking members are preferably formed by openings 92 of the slider 18 and the projections 88 of the inner housing element 26. The openings 92 and the projections 88 engage when the slider 18 is in the open position, wherein the slider 18 preferably cannot be moved further away from the outer housing element 16 (
As shown for example in
With reference to
With reference to
As is also shown in
The connector 10 of
The preceding description is exemplary rather than limiting in nature. Variations and modifications to the disclosed examples may become apparent to those skilled in the art that do not necessarily depart from the essence of this invention. The scope of legal protection given to this invention can only be determined by studying the following claims.
Number | Date | Country | Kind |
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17192169 | Sep 2017 | EP | regional |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2018/073638 | 9/3/2018 | WO | 00 |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO2019/057476 | 3/28/2019 | WO | A |
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International Search Report and Written Opinion from the International Searching Authority for International application No. PCT/EP2018/073638 dated Nov. 9, 2018. |
Number | Date | Country | |
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20210005986 A1 | Jan 2021 | US |