Spring terminal, in particular a front terminal

An electrical connector for connecting the bare end of an insulated conductor with a circuit on a printed circuit board, including a horizontal printed circuit board having an electrical circuit thereon, an electrically conductive contact arrangement mounted on, and electrically connected with the circuit of, the printed circuit board, the contact arrangement including at least two spaced resilient contacts having adjacent end portions that are biased together, a housing formed from electrically insulating material and containing a conductor opening for receiving the conductor bare end; and a positioning arrangement operable by an actuating tool for positioning the conductor bare end in a clamped position between the contact end portions. When the contact arrangement is in the form of a pair of leaf spring contacts connected in a V-shaped manner, an adjusting device is provided for adjusting the space between the adjacent ends of the contacts.

REFERENCE TO RELATED APPLICATIONS

This application is a national stage application under 35 U.S.C. §371 of PCT International Application No. PCT/EP2010/070075 filed Dec. 17, 2010, claiming priority of the German application No. 20 2010 000 681.3 filed Jan. 7, 2010.

BACKGROUND OF THE INVENTION

1. Field of the Invention

An electrical connector for connecting the bare end of an insulated conductor with a circuit on a printed circuit board, including a horizontal printed circuit board having an electrical circuit thereon, an electrically conductive contact arrangement mounted on, and electrically connected with the circuit of, the printed circuit board, the contact arrangement including at least two spaced resilient contacts having adjacent end portions that are biased together, a housing formed from electrically insulating material and containing a conductor opening for receiving the conductor bare end; and a positioning arrangement operable by an actuating tool, such as a screwdriver, for positioning the conductor bare end in a clamped position between the contact end portions.

2. Description of Related Art

In the case of spring terminals, an electrical conductor is mostly pressed against a busbar and is clamped by means of a clamping body. In the process, at least one restoring force, generated by means of a spring, acts upon the clamping body, which, for example, can be adjusted by means of a screw so that the clamping body, as the screw is reset, can again be separated from the conductor. Such a spring terminal with a clamping body that can be adjusted by means of a screw is shown by way of example in publication EP 0 836 242 B1.

In the case of spring force terminals, the conductor, on the other hand, is pressed against an electrically conducting abutment by means of a leaf spring. Such a spring force terminal, for example, is shown in publication DE 20 2005 08168.

The above-mentioned spring terminals and spring force terminals commonly share the fact that, along with the conductor and the bus bar, much structural space is required for the structural parts, especially for clamping bodies and clamping springs that, as such, are not involved in the conduction of the current. To some extent, these parts considerably enlarge the dimensions of the terminals. There is a tendency to make electrical appliances ever smaller; therefore, however, there is a considerable requirement for electrical connection elements with miniaturized dimensions.

In the case of such small connection elements, the parts are accordingly small so that they are difficult, both in terms of their production and when the user wants to use them to connect a conductor.

SUMMARY OF THE INVENTION

Accordingly, the primary object of the present invention therefore is to create a very space-saving electrical connection element that will facilitate the connection of a conductor with a few simple parts and that can therefore be easily handled in terms of its utilization and that is furthermore produced in a very simple and inexpensive manner.

A more specific object of the invention is to provide an electrical connector for connecting the bare end of an insulated conductor with a circuit on a printed circuit board, including a horizontal printed circuit board having an electrical circuit thereon, an electrically conductive contact arrangement mounted on, and electrically connected with the circuit of, the printed circuit board, the contact arrangement including at least two spaced resilient contacts having adjacent end portions that are biased together, a housing formed from electrically insulating material and containing a conductor opening for receiving the conductor bare end; and a positioning arrangement operable by an actuating tool for positioning the conductor bare end in a clamped position between the contact end portions. When the contact arrangement is in the form of a pair of leaf spring contacts connected in a V-shaped manner, an adjusting device is provided for adjusting the space between the adjacent ends of the contacts.

This object is solved with a spring terminal, especially a front terminal for the connection of an electrical conductor with an electrical subassembly with a contact part and with a housing part, whereby, for the purpose of connection with the contact part, the electrical conductor can be stuck into the housing part, whereby the spring terminal has an insertion opening for an actuation means, especially a screwdriver, whereby the contact part comprises a clamping jaw that by means of the actuation member can be adjusted from a shifting state in which the conductor is not clamped together with the clamping jaw into a clamping state in which the conductor is clamped together with the clamping jaw, whereby the clamping jaw conducts current.

According to the invention the contact part that conducts current is provided for the purpose of connecting the conductor with the electrical subassembly so that it is used as such for clamping the conductor; therefore, one does not need any clamping bodies for the purpose of clamping the conductor. As a result, one can save the structural space that is required for these parts and for these subassemblies so that the spring terminal will take up comparatively little structural space and on the whole can be made with very small dimensions. Besides, the number of parts used for the inventive spring terminal is minimized so that supply storage management is good.

In a preferred embodiment the conductor can be arranged by means of the actuation member between the clamping jaws so that the spring terminal by means of the conductor itself can be adjusted from the shifting state to the clamping state. In another preferred embodiment, the interval between the clamping jaws is, in particular, reversible and changeable. As a result, the spring terminal can be switched from the shifting condition into the clamping condition. The shifting is done preferably by means of the actuation member.

Preferably, the clamping jaw is made as a spring, in particular, as a leaf spring. During the adjustment of the contact part, especially during the clamping of the conductor, the clamping jaws therefore are tensed due to their spring properties and during resetting, especially during the removal of the conductor are relaxed. Therefore, no additional springs are needed for the clamping of the conductor so that one can also get along without those springs and so that the needed structural space is very small.

Preferably, the clamping jaw is reversibly adjustable from the shifting state into the clamping state so that the conductor can again be separated out of the spring terminal.

In a preferred embodiment, the spring terminal comprises an adjusting means with which the actuation member cooperates. The adjusting means is preferably provided on the housing part or on the contact part, in particular, on each of the clamping jaws, and makes it possible at least partly to alter the interval between the clamping jaws so that by using the clamping means, one can adjust the spring terminal from the clamping state into the shifting state and back again. With the help of the actuation member, even when the spring terminals have very small practical shapes, it is very easily possible to connect the conductor. The adjusting means is executed as a wedge in a particularly preferred manner.

Preferably, several spring terminals can be lined up one against the other so that they will form a terminal block, in particular, a terminal front block.

In a preferred version, the contact part comprises two clamping jaws between which the conductor can be clamped. Preferably, by clamping the conductor between the clamping jaws, one can at the same time fasten the housing part upon the contact part. The conductor them works as fastening means between the housing part and the contact part so that no further fastening means are needed.

Preferably, the clamping jaws are essentially arranged v-shaped or essentially u-shaped with respect to each other, whereby the clamping of the conductor with the contact part preferably takes place in a form-locking manner.

The actuation member is preferably provided at an angle or parallel to an insertion direction of the conductor.

In a preferred embodiment, the insertion opening is provided on the housing part. As an alternative, the insertion opening can be provided on the contact part. Furthermore, the insertion opening is arranged on a rocker arm that, in particular, can be reset in an elastic manner. In a preferred embodiment, the rocker arm can be rotated around a rotation axis. In this embodiment, the direction of actuation for the actuation member can be provided in an angle, in particular, a right angle with respect to the insertion opening of the conductor into the spring terminal.

In a preferred embodiment, the housing part, when in the shifting state, is not arranged on the contact part. Then the contact part and the housing part are not assembled against each other in the context of the production process. Assembly during the production process is thus omitted so that the terminal spring can be produced in a very reasonably priced manner.

In a particularly preferred manner, by clamping the electrical conductor together with the contact part, the housing part can be fastened upon the contact part. Because the housing part is fastened first by the connection of the conductor in the contact part, one can furthermore get along without parts or without structural measures with regard to the fastening of the contact part in the housing part. That eliminates the terminal assembly of the contact part upon the housing part, and the production of the spring terminal becomes very simple and very cost favorable.

In a preferred manner, the shape of the housing part is so executed in a manner corresponding to the contact part that one can arrange the housing part upon the contact part, whereby, if the conductor is clamped no the contact part, the removal of the housing part from the contact part is no longer possible without the separation of the conductor.

In a further preferred embodiment, the spring terminal comprises an insulation busbar upon which is preferably arranged a guide peg for the guidance of the housing part. That signifies the positioning of the housing part upon the contact part.

In a likewise preferred embodiment, there is arranged on the housing part a stop means so that the housing part can be shifted upon the contact part. In a particularly preferred manner, the stop means are so provided that they will prevent the separation of the housing part from the contact part.

In another preferred embodiment, the contact part is made in the shape of a box. In a particularly preferred manner, the housing part can be inserted into the contact part. This embodiment facilitates a very compact design of the inventive spring terminal.

DETAILED DESCRIPTION OF THE INVENTION

Referring first to the embodiment shown inFigs. 1a-1e, the electrical connector or spring terminal1of the present invention includes a housing2for connecting the bare end4aof an insulated conductor4with a resilient contact arrangement3mounted on an electrical subassembly5. The housing2contains a conductor insertion opening6through which the bare end of the conductor4is inserted in the insertion direction51into the housing2. Furthermore, the housing2contains a tool insertion opening7for receiving an actuation member8inserted in the actuation direction81. Then spring terminal1is shown in an assembling shifting state V, wherein conductor4is not yet attached to the contact arrangement3. In this embodiment, conductor4furthermore in the shifting state can be inserted through the insertion opening6into housing part2.

The shape of housing2and the shape of contact arrangement3are so related that the arrangement of housing2on contact arrangement3can be accomplished in a very simple manner with an actuation member8. Specifically, the tip of the actuation member8in this embodiment is introduced through the tool insertion opening7into housing part2, and during the arrangement of housing2on contact assembly3, the contacts extend into corresponding pairs of contact openings11,11and12,12in the housing, and during the clamping operation, the housing causes the contact pairs to be clamped to the conductor4. Besides, during the fitting of housing part2upon contact part3, respectively during the clamping of conductor4between clamping contacts31,32,33,34, the actuation member8is inserted into the spring terminal arrangement1at a right angle85with respect to insertion direction51of conductor4, so that actuation direction81is arranged at a right angle with respect to insertion direction51.

If housing2is arranged on contact arrangement3with the help of actuation member8during the assembling shifting state V with conductor4inserted in housing part2, then conductor4is clamped between clamping jaws31,32,33,34of contact part3. Spring terminal1is then in a clamping state K.

According to the invention, the contact arrangement3is provided both in a current conducting manner and also for the clamping of an electrical conductor4. In this case, contact arrangement3includes four rod-shaped clamping jaws31,32,33,34, of which two, in each case, are spaced apart from each other and are therefore essentially arranged neighboring each other in a U-shaped manner. Clamping jaws31,32,33,34, therefore, have a closed side38upon which the adjoining clamping jaws31,32,33,34are connected with each other, and an open side39. To facilitate clamping of the electrical conductor4, clamping jaws31,32,33,34are preferably made in a resilient manner.

In this case, actuation member8is guided at a right angle84with respect to insertion direction51of conductor4; therefore, clamping jaws31,32,33,34during the clamping are forced apart on their open side39by conductor4so that the interval10between two neighboring clamping jaw pairs31,32,33,34will become larger.

In the insertion process, clamping jaws31,32,33,34simultaneously clamp housing2upon contact arrangement3so that the housing2can no longer be removed from contact part3without the separation of conductor4. Therefore, by clamping conductor4with contact arrangement3, housing2is attached upon the conductor4. In other words, with conductor4being inserted due to the shifting of housing2that in the assembling shifting state V is not arranged on contact arrangement3, not only will conductor4be clamped together with contact arrangement t3, but the housing2will also be attached upon contact arrangement3.

In the spring terminal1shown here, we are dealing with a front terminal that can be lined up in succession.FIGS. 1a-1dshow spring terminal1in the shifting state V in which conductor4can be shifted in housing part2. InFIG. 1e, spring terminal1is in the clamping state K in which conductor4is clamped together with contact arrangement3and electrically engages the latter.

FIGS. 2a-2dillustrate a second embodiment of the inventive spring terminal1. Here again,FIGS. 2aand2billustrate the arrangement of housing part2of spring terminal1upon contact part3as well as the clamping of conductor4in contact part3, in the shifting state V, andFIGS. 2cand2dillustrate the apparatus in the clamping state K.

This embodiment differs from the embodiment ofFIGS. 1a-1ein that, between conductor plate5and contact part3, there is provided an insulation member9. Insulation member9contains an opening93that affords electrical connection between the contact arrangement3and the circuits on the printed circuit board5. Here, the connection means (not shown) extends from contact assembly through the opening93. Furthermore, the insulation member9includes guide pegs91,92, which, when spring terminal1is in the clamping state K, engage corresponding recesses21,22contained in the housing2. The position of guide pegs91,92and recesses21,22can be adjusted as required in each particular case and differ here inFIGS. 2aand2b, and inFIGS. 2cand2d.

Referring now toFIGS. 3a-3d, a third embodiment of the inventive spring terminal1is shown, including a housing302for connecting the bare end of a conductor4to a contact arrangement303, mounted on a printed circuit board base5. In the assembling shifting state V ofFIGS. 3a-3c, the conductor4can be displaced in housing part2and is not clamped between clamping jaw contacts331,332, whereas in the clamping state K ofFIG. 3d, the conductor4is clamped between clamping jaws331,332of the contact assembly303.

As in the embodiments ofFIGS. 1 and 2, the shape of housing part302and the shape of contact assembly303are so executed in a manner corresponding to each other that it is possible to arrange housing part302upon contact assembly303, in particular, with the help of contact adjusting means325.

In the embodiment ofFIGS. 3a-3d, the contact assembly includes only two clamping jaw contacts331,332, which essentially are arranged in V-shape with respect to each other and which are executed as resilient members, in this case as leaf springs. In the following, the terms “clamping jaw contacts” and “leaf spring contacts” are used synonymously. In the assembling shifting state V, leaf springs331,332are spaced apart from each other upon their open side38, and upon their closed side39, they are preferably connected with each other. A base portion303aof the contact assembly is connected with the printed circuit board5.

Regarding the handling of spring terminal1, this arrangement shows a difference with respect to the embodiments inFIGS. 1 and 2during the connection of conductor4.

In order to be able to clamp conductor4between leaf springs331,332, the interval10between leaf springs331,332on their closed side39must first of all be enlarged. Then conductor4is placed between leaf springs331,332, and subsequently interval10again is reduced until leaf springs331,332come to rest against conductor4and clamp the latter. Starting with the leaf springs331,332, which initially rest against each other inFIG. 3a, the interval10between leaf springs331,332in clamping state K in which conductor4is arranged between them is enlarged.

This embodiment, above all, offers the advantage that conductor4, by widening the interval10between leaf springs331,332with respect to each other, can again be taken out of spring terminal1and that in the process, due to the resetting forces of leaf springs331,332, there will be no deformations so that spring terminal1can be used again.

To alter the interval10between leaf springs331,332, housing part2has an adjusting device325, here in the form of a wedge, which, with the help of actuation member8, can be inserted between leaf springs331,332. The insertion opening7for actuation member8is provided on a particularly resilient rocker arm327so that actuation member8in the actuation direction81is actuated at a right angle85with respect to insertion direction51, whereby adjusting means325is inserted between leaf springs331,332on the closed side39. The insertion opening7for actuation member8is provided here on adjusting means325. In order starting from mutually adjoining leaf springs331,332to be able to insert adjusting means325between leaf springs31,32, the latter are bent outward on their side that faces toward adjusting means25so that adjusting means325engages between leaf springs331,332.

The embodiments ofFIGS. 4-9also include spring terminals1with contact assemblies3, there, in each case, with two clamping jaws defined by mutually V-shaped arranged leaf spring contacts. In these embodiments, there are also provided in each case adjusting means in order first of all to increase the interval of leaf spring contacts from each other starting with the assembling shifting state V so as then to insert conductor4and then to reduce the interval until conductor4in clamping state K is clamped between the leaf spring contacts. Of course, spring terminals1inFIGS. 4-7and9are so provided that actuation member8and conductor4, upon insertion and clamping of conductor4, are arranged somewhat parallel with respect to each other between the leaf spring contacts.

Therefore, inFIGS. 4a-4g, there is provided in each case an adjusting means435,436on each leaf spring431,432, whereby the adjusting means435,436in each case are so arranged with respect to each other in the form of a wedge that the tip of the actuation tool8can be inserted via the longitudinal tool passage7on the open side38between adjusting means435,436, and on the closed side39will in the process increase interval10between leaf springs431,432.

In the embodiment ofFIG. 4, spring terminal1offers the advantage that, owing to the generally L-shaped configuration of the contact assembly403, the arrangement of spring terminal1upon printed circuit board5is possible both in an alignment parallel to an insertion direction51of conductor4into housing part2, and in an alignment normal with respect to insertion direction51. More particularly,FIG. 4gshows the arrangement of spring terminal1upon a printed circuit board5, which is arranged normal with respect to insertion direction51of conductor4.

In the embodiment ofFIGS. 5a-5g, a wedge-shaped adjusting means525is arranged for displacement on housing502.

Actuation direction81for actuation tool8via opening7is provided parallel to insertion direction51of conductor4, so that adjusting means525is guided in actuation direction81starting from the open side38between leaf spring contacts531,532until the latter are pressed apart from each other on their closed side39and conductor4can be inserted between leaf spring contacts531,532. Adjusting means525is preferably provided in a resilient return fashion by return spring means (not shown), so that upon retraction of actuation tool8against actuation direction81, adjustment will take place likewise against actuation direction81. In the process, leaf spring contacts531,532are also restored until they rest against conductor4and clamp the latter.

In the embodiment ofFIGS. 6a-6e, a rotatable wedge625is arranged on the housing602and has a generally oval cross-sectional configuration, thereby defining an adjusting means between the leaf spring contacts631and632. For this purpose, the leaf spring contacts include on their closed side39in each case an extension portion612,622between which the adjusting means625is arranged. Therefore, the interval10between leaf spring contacts can be enlarged on their closed side39upon rotation of the adjusting means. Here again, the rotation is done by means of actuation member8, which is inserted parallel to insertion direction51of conductor4into the insertion opening. Here again, after the insertion of conductor4between the leaf spring contacts631and632by turning adjusting means625back, leaf springs631and632are released until they rest in clamping engagement against conductor4.

FIG. 6ashows the housing602separate from each other,FIGS. 6b-6dshow the spring terminal1in the adjusting state V, andFIG. 6eshows spring terminal1in the clamping state K.

FIGS. 7a-7bsimilarly illustrate a modification of spring terminal1for two conductors4, whereby in this case, for each conductor4, there are provided in each case two pairs of adjacent V-shaped leaf spring contacts731,732and733,734, with only one adjusting means725is provided on housing702for the purpose of altering interval10of the closed side39of leaf spring contacts731,732and733,734from each other. Therefore, interval10of leaf spring contacts731,732,733,734from each other can be adjusted here simultaneously for both conductors4.

FIG. 7ashows spring terminal1in the clamping state K, andFIG. 7bshows spring terminal1in the disassembled shifting state V, wherein the conductors4are separated from the spring terminal1.

FIGS. 8aand8billustrate an eighth embodiment of the inventive spring terminal, including a wedge-shaped adjusting means835arranged on the pivotable rocker arm840of contact assembly803. Rocker arm840is pivotally connected with contact assembly803by means of a hinge871and can be swung around a pivot axis872. Insertion opening7contained in the rocker arm840is adapted to receive the tip of the actuation tool8, which, upon actuation, opens contact part3.

Leaf spring contacts831,832, analogous to those of the embodiment ofFIG. 3, are connected in a V-shaped fashion and have an open side38and a closed side39, whereby in the shifting state V on the open side38, they are spaced apart from each other, and on the closed side39, they rest against each other.

Starting from adjoining leaf spring contacts831,832, in order to be able to insert adjusting means835between leaf springs831,832, the latter are bent outwardly on their sides facing the adjusting means835.

To actuate adjusting means835by means of actuation member8, the latter is so displaced that it will be arranged parallel to the insertion direction51of conductor4, so that it will engage between leaf spring contacts831,832. Actuation member8is actuated in the actuation direction81at a right angle85with respect to insertion direction51. Then adjusting means835can be inserted on closed side39between leaf spring contacts831,832so that interval10(seeFIG. 3) of leaf springs831,832with respect to each will become greater.

Conductor4is guided from open side38between the two leaf spring contacts831,832until it is arranged on closed side39between leaf springs831,832.

Rocker arm837is preferably connected in a resilient manner, so that during the resetting of actuation member8against actuation direction81, it will swing back. As the result, leaf spring contacts831,832at their closed end39, are also reset so that their interval again will be reduced until leaf spring contacts831,832rest against conductor4and clamp the latter.

FIGS. 9a-9iillustrate a ninth embodiment of an inventive spring terminal1for connecting a conductor4with an electrical subassembly or printed circuit board5.

Contact part3of spring terminal1is made in the shape of a box and therefore has four box walls931,932,933,934, which essentially are arranged at a right angle with respect to each other. In two opposite box walls931,932, there are provided two clamping jaw contacts935,936, which are arranged in V-shaped fashion with respect to each other, whereby clamping jaw contacts935,936on their closed side39point into the interior of contact assembly903. For connection with an electrical subassembly5, contact assembly903furthermore has two contact feet951,952, which are bent outwardly from box wall934.

It will be apparent that an embodiment of contact assembly903with only one clamping jaw935is also possible, in which case conductor4can be clamped between clamping jaw935and the opposite box wall932.

With a first end923, which can be stuck into contact assembly903, housing902can be inserted into the interior of contact assembly903. It has a second end924that cannot be inserted into contact assembly903upon which are arranged the insertion opening6for conductor4as well as the insertion opening7for actuation member8. Insertion opening7and insertion opening6are so arranged with respect to each other that actuation member8in an actuation direction81can be actuated parallel to the insertion direction51of conductor4. Conductor4is guided starting from the open side38of contact assembly903between clamping jaws935,936.

Housing902has adjusting means925which, upon activation of the actuation member8in actuation direction81, is inserted between clamping jaws935,936. As a result, clamping jaws935,936on their closed side39are pressed apart from each other so that conductor4can be inserted between clamping jaws935,936.

During the retraction of actuation member8against actuation direction81, clamping jaws935,936, due to their reset force, are reset. In the process, conductor4is clamped between clamping jaws935,936. Housing902in the process is also shifted against actuation direction81.

On the first end, which can be inserted into contact assembly903, stop means928(FIG. 9a) are provided on housing902. After insertion into contact assembly903against actuation direction81, housing902therefore can be pulled out of contact assembly903only so far until the stop means928rest against contact assembly903. Because housing902by means of stop means928is attached upon contact assembly903, it cannot automatically be separated from contact assembly903during the shifting action against the actuation direction81.

In the modification ofFIG. 9i, a second insulating housing part100is provided around contact part3.

A screwdriver8can be used advantageously as actuation member in all embodiments. Housing2is preferably formed from an insulating material, in particular, a synthetic plastic substance.

Contact assembly3is formed from a conductive material, in particular, a metal or a metal alloy. The resilient clamping jaws31,32,33,34are preferably made of a metal with good restoring properties. Because clamping jaw contacts31,32,33,34furthermore conduct current, the preferred material at the same time has good conductive properties. The inventive spring terminal can be made with miniaturized dimensions.

While in accordance with the provisions of the Patent Statutes the preferred forms and embodiments of the invention have been illustrated and described, it will be apparent to those skilled in the art that changes may be made without deviating from the invention described above.