Patent Application
20050095904
The invention relates to a plug-in jumper for electrical junction and/or connecting terminals, especially terminal blocks, for elastic engagement in openings in busbars and for electrical contact-making of busbars of at least two junction and/or connecting terminals, with a jumper bar, the jumper bar having a bar strip and several plugs which are connected to the bar strip and each plug having at least two contact legs which are located essentially parallel to one another, of which at least one is made elastic. In addition, the invention relates to electrical junction and/or connecting terminals, especially terminal blocks, with a housing, with at least one busbar, with at least two connecting elements and with a detachable plug-in jumper.
Electrical junction and/or connecting terminals, especially terminal blocks, have been known for decades and are used in the millions in the wiring of electrical systems and devices. The terminals are generally locked onto mounting rails which for their part are often located in a plurality in a switchgear cabinet. In terminal blocks the conductor terminal elements are mainly screw terminals or tension spring terminals. The clamping principle in tension spring terminals is similar to that of screw technology. While in a screw terminal a tension sleeve pulls the conductor against the busbar by actuation of the terminal screw, in a tension spring terminal this task is assumed by the tension spring. In addition however there are also terminal blocks with conductor terminal elements which have cutting blades which cut the insulation of the inserted conductor and make contact with the core of the conductor.
Electrical terminal blocks are generally connecting terminals so that they have at least two conductor terminal elements which are electrically connected to one another via an electrically conductive connecting bar, the busbar. These terminal blocks are also called feed-through terminals. In addition to this basic type of terminal block there is moreover a host of different types of terminal blocks which are specially adapted to the respective applications. Examples here are two-tier, three-tier or four-tier terminals and three-conductor or four-conductor terminals which then each have a correspondingly larger number of conductor terminal elements. Two-tie, three-tier or four-tier terminal which are generally also called tiered terminals, have thus two, three or four busbars which are located on top of one another in different planes and which each electrically connect two conductor terminal elements at a time to one another.
To reduce the wiring cost for terminal blocks which are locked on a mounting rail next to one another, using plug-in jumpers with a corresponding number of plugs is known, the plugs of the plug-in jumper being inserted in the corresponding openings in the busbars of the individual terminal blocks, by which the individual busbars or the individual terminal blocks are electrically connected to one another.
The initially described plug-in jumper and/or the initially described electrical junction and/or connecting terminal is known for example from DE 44 11 306 C1. The known plug-in jumper is characterized in that it has two jumper bar segments which are located next to one another and on which one contact leg at a time per plug is made, the spring loading of the plug taking place parallel to the lengthwise direction of the bar strip. The two jumper bar sections can be simple stampings so that the known plug-in jumper can be produced very easily.
DE 42 23 540 A1 likewise discloses a plug-in jumper in which however the spring forces of the contact legs upon insertion into the opening of the busbars are aligned transversely to the lengthwise direction of the bar strip. It is however common to the two known plug-in jumpers that they can only be used when the same types of terminal blocks are arranged in a row next to one another. For example, with these plug-in jumpers several identical feed-through terminals can be electrically connected to one another.
DE 195 33 992 C1 discloses an electrical tiered terminal with two busbars which are located on top of one another, in which an electrical connection of the two busbars is possible by means of a plug-in jumper which has only one plug which can be inserted into the two plug openings which are flush with one another in the busbars. In particular, the known plug-in jumper consists of two spring contacts which adjoin one another flat and which in the area of their top contact zone which interacts with the upper busbar have offsets which are pointed in opposite directions to one another. When the plug-in jumper is inserted into the two openings of the two busbars this leads to elastic spreading of the two spring contacts in the opening of the top and the bottom busbar, which spreading takes place in opposite directions, by which the plug-in jumper makes contact with the two busbars. Thus an electrical connection of two busbars of a terminal block can be accomplished by this known plug-in jumper.
The object of this invention is to make available a plug-in jumper for electrical junction and/or connecting terminals which makes it possible to interconnect even different types of terminal blocks, especially those terminal blocks with different conductor terminal elements.
This object is achieved in the initially described plug-in jumper in that the plugs have two contact areas located on top of one another for contact-making of two busbars of two electrical junction and/or connecting terminals which are located on top of one another, the two busbars being located on a different plane. In contrast to the plug-in jumper known from DE 44 11 306 C1 which underlies the invention, with the plug-in jumper as claimed in the invention thus terminal blocks can also be electrically connected to one another which have different conductor terminal elements in which the busbars which connect to one another the conductor terminal elements of a terminal block are located on different planes.
Based on the different connection principles, specifically in conventional terminal blocks in which the conductor terminal elements are made as screw terminals, the busbars are located higher than in those terminal blocks in which the conductor terminal elements are made as tension spring terminals or as cutting blades. The relative height difference of the busbars relates to the distance of the individual busbars to the mounting rails for two terminal blocks which are locked next to one another on a mounting rail. By providing at least two contact areas located on top of one another on each plug of the plug-in jumper it is thus possible for one plug with its lower contact area to be inserted into the opening of the busbar of a first terminal block, while at the same time another plug of the plug-in jumper with its upper contact area is inserted in the opening of the busbar of a second terminal block with a busbar which lies in another plane. Thus, with one plug-in jumper two busbars of two different terminal blocks, which busbars are located on different planes, can be electrically connected to one another.
According to one preferred embodiment of the invention, the plugs and the contact legs have different widths, the width of a plug being matched to the width of the busbar or to the width of the opening in the busbar. Generally the individual contact legs of a plug are of the same width so that all contact legs of one plug are narrower than the contact legs of another plug. In this way it is possible with the plug-in jumper as claimed in the invention to interconnect even two or more terminal blocks which are designed for connection of conductors with different conductor cross sections. If conductors with a larger conductor cross section are to be connected to a terminal block, this terminal generally also has busbars with a greater width and thus also wider openings as a result of the higher current flowing over the thicker conductors.
According to one advantageous configuration of the plug-in jumper as claimed in the invention, the jumper bar is made such that the spring forces of the plugs or contact legs are pointed parallel to the lengthwise direction of the bar strip upon insertion into the openings of the busbar and upon contact-making of the busbar. The principle of contact-making of a busbar thus corresponds essentially to the contact-making principle of the plug-in jumper known from DE 44 11 306 C1.
In contrast to this known plug-in jumper, the plug-in jumper as claimed in the invention however advantageously has three contact legs which are arranged essentially parallel to one another, of which at least the middle contact leg is made elastic. If only the middle contact leg is made elastic—and the two outer contact legs are made relatively stiff—twisting of the plug-in jumper perpendicular to the lengthwise direction of the bar strip and thus perpendicular to the lengthwise direction of the plug-in jumper is prevented, by which insertion of the plug-in jumper into a host of terminal blocks which are located next to one another is facilitated.
According to another advantageous embodiment of the plug-in jumper as claimed in the invention, a lengthwise slot is made in at least one contact leg. In the above described preferred embodiment with three contact legs, at least the middle contact leg is provided with the lengthwise slot. The execution of the lengthwise slot reduces the reset force as a result of deflection of the contact leg upon insertion into the opening of the busbar, by which especially the insertion force in the upper contact area is reduced so that the insertion or push-through force through the opening of the upper busbar hardly differs from the insertion force into the opening in the lower busbar.
According to a last advantageous embodiment of the plug-in jumper as claimed in the invention which will be briefly mentioned here, the contact legs underneath the lower contact area on at least one narrow side have a ramp bevel. In this way the insertion of the contact leg into an opening of the lower busbar is further facilitated. Moreover, the lower contact area can be bordered to the top by a laterally projecting offset so that with the corresponding dimensioning of the opening, defined insertion of the plug-in jumper into the terminal block is ensured.
In the initially described electrical junction and/or connecting terminal with a busbar which has an opening for elastic engagement and electrical contact-making of the plug-in jumper, the above described object is achieved in that for a plug-in jumper which has a jumper bar with a bar strip and several plugs connected to the bar strip the plugs have two contact areas which are located on top of one another for contact-making of two busbars of two electrical junction and/or connecting terminals which are located on top of one another, the two busbars being located on different planes.
If it has been stated above that the plug-in jumper is made for electrical connection of two junction and/or connecting terminals which are located next to one another, it is on the one hand also naturally possible to interconnect clearly more than two junction and/or connecting terminals with the plug-in jumper. On the other hand, it is not necessary for the junction and/or connecting terminals which are to be electrically connected to one another to be located directly next to one another. In particular, it is also possible, with a plurality of terminal blocks locked on a mounting rail, to interconnect only a few specific ones, for example the first third, fourth, seventh and tenth terminal block by a correspondingly made plug-in jumper. In this plug-in jumper then the distances between the individual plugs are made accordingly; this can preferably be accomplished by removing the plugs which correspond to the terminal blocks which are not to be electrically connected to one another, for which in the transition area between the bar strip and the individual plugs the corresponding scored locations are provided.
In particular there are a host of possibilities for embodying and developing the plug-in jumper as claimed in the invention and the electrical junction and/or connecting terminal as claimed in the invention. In this regard reference is made both to the claims -which are subordinate to claim 1 and also to the following description of preferred embodiments in conjunction with the drawings.
FIGS. 1 to 3 show perspectives of various applications of a first embodiment of the plug-in jumper as claimed in the invention, each together with two busbars of two terminal blocks,
The figures each show a plug-in jumper 1 for elastic engagement in openings 2 which are made in the busbars 3, 30 of electrical terminal blocks which are not shown here. Each busbar 3, 30 is located in the housing of the electrical terminal block and is used for electrically conductive connection of two connecting elements of the terminal block. The busbar 3 is one which typically is used in terminal blocks with tension spring terminals, while the busbar 30 is one which is used in terminal blocks with screw terminals.
The plug-in jumper 1 has a jumper bar which is made comb-like and which has an upper bar strip 5 (
In the embodiments as shown in FIGS. 1 to 3, each plug 6 has two separate contact legs 7, 8. In contrast, in the embodiments shown in FIGS. 4 to 6 each plug 6 has three contact legs 7, 8, 9. If the plugs 6 of the plug-in jumpers 1 have only two contact legs 7, 8, preferably the two contact legs 7, 8 are made elastic. If the plugs 6 conversely have three contact legs 7, 8, 9, preferably only the middle contact leg 9 is made elastic, while the two outer contact legs 7, 8 are made relatively stiff.
It is common to all plugs 6 or all plug-in jumpers 1 that they have two contact areas 10, 11 which are located on top of one another so that there is the possibility of electrically interconnecting two busbars 3, 30 of two terminal blocks which are located next to one another, the two busbars being located on a different planes I, II. When the plugs 6 or the contact legs 7, 8, 9 are inserted into the openings 2 of the busbars 3, 30 the plugs 6 make contact in the lengthwise direction L of the bar strip 5. In doing so the lengthwise direction L of the bar strip 5 or the plug-in jumper 1 runs roughly perpendicular to the lengthwise direction of the busbars 3, 30.
The above described direction of the spring forces which arise due to the plugs 6 when the plugs 6 are inserted into the openings 2 is achieved in that the plugs 6 in the unloaded state, i.e., in the uninserted state, have a width which is greater than the width of the opening 2. This is achieved in that the contact legs 7, 8, 9 in the unloaded state are slightly offset to one another in the unloaded state in the lengthwise direction L. In the embodiment as shown in FIGS. 4 to 6 only the middle contact leg 9 in the lengthwise direction L of the bar strip 5 is located slightly offset to the two outer contact legs 7, 8. This is achieved by deflecting only the middle contact leg 9 when the plug 6 is inserted into the opening 2 of the busbars 3, 30, by which twisting of the plug-in jumper 1 perpendicular to the lengthwise direction L is prevented. Thus, the insertion of the plug-in jumper 1 with a plurality of plugs 6 into a corresponding number of terminal blocks is facilitated.
The embodiments as shown in FIGS. 1 to 3 differ by the use of the plug-in jumper 1 which is identical at the time together with different busbars 3, 30, i.e. by use with different terminal blocks. In the embodiment as shown in
In the second embodiment shown in
In the plug-in jumper 1 which is shown in FIGS. 1 to 3, the plug 6 which is the front one in the plane of the drawings is somewhat narrower than the rear plug 6, since in the embodiments which are shown there the front busbar 3, 30 is likewise narrower than the rear busbar 30, 3. The width of the plug 6 is always matched to the width of the opening 2 in the busbar 3, 30. Since the different terminal blocks have only a limited number of different busbar widths, overall only a few plug-in jumpers 1 with different combinations of plug widths are necessary to be able to connect almost all types of different terminal blocks to one another.
FIGS. 3 to 5 show embodiments in which the busbars 3, 30 both make contact with the plugs 6 in the lower contact area 10 or both with the plugs 6 in the upper contact area 11. Overall because each plug 6 has two contact areas 10, 11 which are located on top of one another, it becomes possible to electrically interconnect different busbars 3, 30 and thus different terminal block types by the plug-in jumper 1.
The contact legs 7, 8, 9 are made such that their width B is greater than their thickness D. In this way, on the one hand a relatively narrow plug-in jumper 1 can be accomplished, on the other hand relatively large spring forces arise when the contact legs 7, 8, 9 are loaded in the lengthwise direction L of the bar strip 5, so that sufficient contact force is ensured. In order to facilitate the insertion of the plugs 6 into the openings 2 of the busbars 3, 30, the contact legs 7, 8, 9 underneath the lower contact area 10 on at least one narrow side have a ramp bevel 13.
As is especially apparent in
For additional safeguarding of the connection of the individual jumper bar segments 14, 15, 16 and for electrical insulation, the plug-in jumper 1 has an insulating head 19 which extends over the bar strip 5. In the insulating head 19 which sits frictionally tight on the bar strip 5, there is a recess 20 which runs in the lengthwise direction L which can be used to pull out or disengage the plug-in jumper 1 using the tip of a screwdriver.
| Number | Date | Country | Kind |
|---|---|---|---|
| 103 37 400.0 | Aug 2003 | DE | national |
| 103 51 289.6 | Oct 2003 | DE | national |
