DE29807956U1 - Terminal with knee lever operation - Google Patents

Abstract

Connecting terminal has housing (10) for the connecting contact (16) and a tensioning/clamping spring (20) having a first limb (18) supported on the connecting contact (16) and a free spring limb (24) which becomes a clamping end (26) via a deflection knee (28). The first lever arm (36) is hinge-mounted in the housing (10) and a free end (46) of the second lever arm (38) is coupled to the spring arm (24).

Description

STREET

Patent attorneys

European Patent Attorneys °

European trademark attorneys

Dipi.-ing. Joachim Strasse °*

Dr.rer.nat. ALFONS J. HOFSTETTER °'

Dr.-ing. Eduard F. Schurack ^&lgr;

Of Counsel

Dr. jur. Peter C. Bittner

Authorized representatives at

" European Patent Office
' European Office for Harmonization in the Internal Market (Trade Marks and Designs)

Attorney file: 24724

WECO Wester, Ebbinghaus GmbH & Co. KG

Donaustr. 15

63452 Hanau

German utility model application

Connection terminal with toggle lever operation

BALANSTRASSE 57 · D-81541 MUNICH

TELEPHONE +49/(0)89 - 45 09 18 0 · FAX +49/(0)89 - 45 09 18 12 · VOICE +49/(0)89 - 45 09 18 20

EMAIL Strasse-Hofstetter@T-Online.de

WECO Wester, Ebbinghaus GmbH &*Co. *KG ArtPainting file: 24724

63452 Hanau

German utility model application

Connection terminal with toggle lever operation

The present invention relates to a connection terminal with a housing, with a connection contact arranged in a fixed manner in the housing, with a clamping spring with a first leg which is arranged to support the connection contact, with a free spring leg which passes over a bending knee into a clamping end, whereby the clamping end has a clamping edge which engages under the connection contact, with an actuating element which is pivotably mounted in the housing and engages the spring leg of the clamping spring, which in a clamping position releases the spring leg so that its clamping end with its clamping edge pulls a conductor inserted into the housing against the connection contact, and in an open position presses the spring leg down so that the clamping edge is lifted off the connection contact in order to insert a conductor, whereby the actuating element has a first and a second lever arm.

Such a connection terminal is known from DE 196 11 762. In the connection terminal according to DE 196 11 762, the two arms of the actuating element are rigidly connected to one another. A tool, for example a screwdriver, can be used from the outside at one end of the arm to pivot the actuating element into the open position, with a corresponding opening being provided in the housing that allows the actuating element to pivot. To lock the actuating element in the open position, the end of the other lever arm has a nose that is pivoted so far over the bending knee in the open position that the actuating element is held in the open position in a self-locking manner. After inserting a conductor into the connection terminal, the actuating element can be pivoted in the opposite direction.

Direction to release the spring travel, thereby clamping the conductor to the connection contact.

This terminal has several disadvantages: Due to the direct contact of the actuating element with the clamping spring, which in turn is conductively connected to the connection contact, the actuating element must be designed to be non-conductive. This is necessary because the actuating element must be accessible from the outside due to its design and therefore a conductive design would entail the risk of electric shocks.

It will therefore be made of plastic, particularly with regard to the mass production of terminals. Since many such terminals are usually arranged parallel to one another, another boundary condition is the required, small overall width. This inevitably involves thin material walls of the actuating element. If the actuating element is frequently stressed with a screwdriver, there is a risk of one of the side walls of the actuating element breaking off, which can be facilitated by the aging of the plastic used for this purpose.

A further disadvantage is that the actuating element is not covered by the housing over a large part due to its design. In the embodiment shown in DE 196 11 762, one end of the actuating element even extends beyond the housing. There is therefore a risk of accidental actuation.

For the actuating element to lock itself in the open position, the actuating element must be mounted precisely on a pivot. Wear on the nose can lead to the self-locking state no longer being maintained, i.e. the clamping spring springing back into the clamping position by itself. Since the actuating element must sit exactly on the pivot, high demands must be placed on the manufacturing tolerances.

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Accordingly, it is the object of the present invention to provide a connection terminal which allows greater manufacturing tolerances during production and which also functions reliably during long-term operation.

According to the invention, this object is achieved in that the first lever arm is pivotally connected to the second lever arm, wherein a free end of the first lever arm is pivotally mounted in the housing, and a free end of the second lever arm is coupled to the spring leg.

This solution also offers the advantage of making it possible to house such a lever mechanism entirely inside the housing. This effectively prevents accidental activation. This design principle with a so-called knee lever also makes it possible to reduce the overall height.

Another significant advantage is that when the clamping spring is brought into the open position, according to the toggle lever principle, the force exerted by the lever increases steadily as it is opened further, since the load path becomes very small in relation to the force path. The increase in the clamping force of the clamping spring is effectively compensated by this working principle.

It is particularly advantageous to mount the first and second lever arms in the housing in such a way that their position in the open position is self-locking. This eliminates the need to maintain the tension of the clamping spring by constantly applying force from the outside, for example using a screwdriver.

This is preferably achieved by the connection of the first and second lever arms being able to pivot beyond their dead center for self-locking.

In order to pivot the lever arms against each other and thereby tension the clamping spring, the housing can be pivoted in the area of the pivoting

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The two lever arms can have an opening for a clamping tool in the pivotable connection of the two lever arms. However, it can also be provided that an opening for a clamping device that can be operated from outside the housing is provided in the housing in the area of the pivotable connection, whereby the clamping device can be slidably mounted in the housing and firmly connected to the housing. In a further development, it can be provided that such a clamping device is connected to at least one lever arm in such a way that in addition to clamping, the clamping spring can also be released by operating the clamping device.

However, instead of this or in addition, at least one of the lever arms can be connected to an actuating device, with which the clamping spring can be tensioned and/or released. It is particularly advantageous to arrange the actuating device in or in relation to the housing in such a way that it can only be actuated when the clamping spring is tensioned. This ensures that after inserting a conductor into the connection terminal, i.e. when the spring is tensioned, a relaxation, i.e. clamping of the conductor, can be triggered, while after the conductor has been clamped, the actuating device is no longer accessible and thus an accidental release of the conductor is prevented.

It can be provided that the actuating device is designed in such a way that it extends out from a first side of the housing, whereby it is guided around the housing, at least partially, in such a way that it is visible and operable from another side of the housing. This has the advantage that when the terminal is installed with the rear side inaccessible, three work steps can be carried out from one side of the terminal: firstly, inserting a conductor, secondly, tensioning the spring by inserting a tensioning device or activating the tensioning device provided in the housing and thirdly, releasing the clamping of the conductor by activating the actuating device.

The first lever arm can be pivotally connected to the second lever arm via a pin or a rivet. However, it can also be provided that the first lever arm is formed in one piece with the second lever arm, whereby the two lever arms can be produced in a cost-effective manner, for example by a plastic die-casting process in one operation.

Further advantageous developments of the invention are defined in the subclaims.

In the following, embodiments of the invention are described in more detail with reference to the accompanying drawings. They show:

Figure 1 shows a first connection terminal according to the invention in the open position;

Figure 2 shows the embodiment according to Figure 1 in the clamping position ;

Figure 3 shows a second embodiment of the connection terminal according to the invention in the open position;

Figure 4 shows the embodiment according to Figure 3 in the clamping position;

Figure 5 shows a third embodiment of the connection terminal according to the invention in the open position;

Figure 6 shows the embodiment according to Figure 5 in the clamping position;

Figure 7 shows a fourth embodiment of the connection terminal according to the invention in the open position; and

Figure 8 the embodiment according to Figure 7 in the clamping position
lation.

The connection terminal shown in Figure 1 has a housing made of plastic, with pins 12 and holes 14 provided in the housing 10 in order to join several such connection terminals together to form a terminal block. The housing 10 has a front side 11, through which a conductor can be fed, and a rear side 13. Each housing 10 has a closed side wall, which covers and closes the opposite, open side wall of the adjoining housing 10 when the housings 10 are assembled. The open side surface of the last housing 10 of the terminal block is closed by a correspondingly attached side plate (not shown).

In the housing 10 there is a connection contact in the form of a contact bracket 16. This contact bracket 16 can be inserted into the housing 10 via the open housing side and is held in the housing without additional fastening means, simply by suitable shaping of the housing interior. A first leg 18 of a clamping spring 20 lies between a part of the contact bracket 16 and a holding projection 22 and is thus held in the housing 10 without additional fastening means. In continuation of the leg 18, the clamping spring 20 is bent in a U-shape around the holding projection 22. A freely springy spring leg 24 of the clamping spring 20 is formed above the holding projection 22. The front end of the spring leg 24 is bent downwards essentially at a right angle, so that a clamping end 26 is formed. The transition of the spring leg 24 into the clamping end 26 is formed by a bending knee 28 that is curved in a circular arc around the front end of the retaining projection 22. The clamping end 26 has an opening 30 through which the front end 32 of the contact bracket 16 extends.

If the spring leg 24 of the clamping spring 20 is pressed downwards against its spring force, the lower free end of the clamping end 26 is pressed downwards into a receptacle of the housing 10. In this open position of the connection terminal, an insertion opening 34 of the housing 10 is aligned with the opening 30 of the

Clamping end 26. In this position, an electrical conductor (not shown) with its stripped wire can be inserted into the insertion opening 34 and passes through the opening 30. The spring leg 24 can then be released, as shown in Figure 2. Due to its elasticity, the spring leg 24 pivots upwards, whereby the clamping end 26 is pulled upwards. This takes the wire of the conductor passing through the opening 30 of the clamping end 26 with it. The wire is thereby clamped between the contact bracket 16 and the lower clamping edge of the opening 30 under the spring force of the spring leg 24. In this way, the conductor is reliably brought into conductive contact with the contact bracket 16 and held.

To actuate the clamping spring 20, an actuating member having a first lever arm 36 and a second lever arm 38 is arranged above the retaining projection 22 in a free space 40 of the housing 10. The first lever arm 36 is pivotally connected to the second lever arm 38, for example by a pin 42 or a rivet. While the free end 44 of the first lever arm 36 is pivotally supported in the housing 10, the free end 46 of the second lever arm 38 is in contact with the spring leg 24 of the clamping spring 20. By suitably designing a housing projection 48 and dimensioning the play between the first and second lever arms, it is achieved that the entire actuating member only needs to be inserted into the housing 10 without the need for additional fastening or holding means. The free end 44 of the first lever arm 36 and the free end 46 of the second lever arm 38 are rounded to facilitate sliding during the pivoting movement in the housing area 48 or on the spring leg 24 of the clamping spring 20. In the open position of the connection terminal shown in Figure 1 , the angle a that the first lever arm 36 forms with the second lever arm 38 is more than 180°. This angle cannot be exceeded because the first lever arm 36 rests on a stop area 50 and the second lever arm 38 rests on a stop area 52 of the housing 10.

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In this position, the spring force of the clamping spring 20 causes self-locking, i.e. the clamping spring 20 cannot change into the relaxed state without external intervention. The safety reserves for the self-locking can be varied by varying the angle of the stop areas 50 and 52. In this state, an actuating device 54, which is connected to the first lever arm 36 and protrudes from the housing through a housing opening 57, is visible and can be actuated from the outside. A projection 56 of the housing 10 secures this actuating device 54 against accidental contact.

After inserting a conductor through the insertion opening 34, the actuating device 54 can be pressed downwards to clamp the conductor, whereby the pivoting connection of the first and second lever arms can be pushed back past the dead center, which in turn automatically closes the terminal. The actuating device 54 also serves to indicate the status of the connection terminal, i.e. whether it is in the open position or the clamped position.

The clamping position is shown in Figure 2. In the clamping position, the actuating device 54 is visible through the housing opening 57, but cannot be actuated, and in particular cannot be actuated accidentally. In order to move the connection terminal from the clamping position shown in Figure 2 to the open position shown in Figure 1, a tool, such as a screwdriver, is used to press through the housing opening 58 against the toggle lever formed by the first lever arm 36 and the second lever arm 38 until the self-locking open position shown in Figure 1 is reached. In this position, the conductor inserted through the insertion opening 34 is released again by the clamping end 26 of the clamping spring 20.

Figures 3 and 4 show a further embodiment of the connection terminal according to the invention. The components corresponding to Figures 1 and 2 are marked with corresponding reference numbers.

φ ·

In this embodiment, a push button 60 is slidably mounted in the housing 10. By inserting the push button 60, the clamping spring 20 can be tensioned. To release the tension, the push button 60 has a projection 62 which interacts with a return hook 64 attached to one of the two lever arms in order to release the spring. So that the push button 60 does not have to be pulled out of the housing 10 by hand when releasing it, corresponding spring means can be provided which interact with corresponding locking means in order to set defined tensioning or release states. It is obvious to the person skilled in the art that instead of a return hook and a projection, a corresponding groove can also be provided into which the return hook 64 engages. Figure 3 shows such a connection terminal in the open position, while Figure 4 shows a corresponding connection terminal in the clamping position.

The embodiment shown in Figures 5 and 6 is based on the embodiment shown in Figures 1 and 2, but is further developed in that the actuating device 54 has an extension 68 and is guided around the upper side of the housing 10 in such a way that it can be seen and actuated from the side of the connection terminal on which the insertion opening 34 for the conductor is located. This has the advantage that the connection terminal itself, when installed, only needs to be accessible from the front 11 in order to move the connection terminal from the open position to the clamped position and vice versa.

The embodiment shown in Figures 7 and 8, where Figure 7 shows the open position and Figure 8 shows the clamping position, is particularly simple and inexpensive to implement in terms of manufacturing costs. In this embodiment, the first lever arm 3 6 and the second lever arm 3 8 are formed as one piece. The two lever arms are pivotally connected to one another via a constriction 66, whereby the entire lever construction can be assembled in the pressure

is made from plastic using a casting process. This eliminates the need to form holes to insert a rivet or a pin. By appropriately forming the projection 48, it is ensured that the first and second lever arms in the clamping position do not fold together so tightly that they fall out of the housing 10 through the housing opening 58. By appropriately selecting the stiffness of the constriction 66 - in particular through its diameter and length - a secure tensioning of the clamping spring 20 in the open position is achieved. This can be supported by suitable plastic shaping of the first and second lever arms, see the structure shown in dashed lines.

It is clear to the person skilled in the art that further embodiments of the inventive concept are possible. For example, it is not necessary for the free end 46 of the second lever arm 38 to be directly connected to the clamping spring 20. Rather, the force transmission can also be effected via an intermediate connecting element.

Claims (13)

WECO Wester, Ebbinghaus GmbH & fco. KG Attorney's file: 24724 63452 Hanau German utility model application Terminal with toggle lever operation Claims: 1. Connection terminal with a housing (10), with a connection contact (16) fixedly arranged in the housing (10),
with a clamping spring (20) with a first leg (18) which is arranged to support the connection contact (16), with a free spring leg (24) which passes over a bending knee (28) into a clamping end (26), wherein the clamping end (26) has a clamping edge which engages under the connection contact (16), with an actuating member pivotably mounted in the housing (10) and engaging the spring leg (24) of the clamping spring (20), which in a clamping position releases the spring leg (24) in such a way that its clamping end (26) with its clamping edge pulls a conductor inserted into the housing (10) against the connection contact (16), and in an open position presses down the spring leg (24) so that the clamping edge is lifted off the connection contact (16) for inserting a conductor, the actuating element having a first (36) and a second lever arm (38),
characterized, that the first lever arm (3 6) is pivotally connected to the second lever arm (3 8), wherein a free end (44) of the first lever arm (36) is pivotally mounted in the housing (10), and a free end (46) of the second lever arm (38) is connected to the Spring leg (24) is coupled. 2. Connection terminal according to claim 1,
characterized, that the first (36) and second lever arm (38) are mounted in the housing (10) in such a way that their position in the open position is held in a self-locking manner. 3. Terminal according to claim 2,
characterized, that the connection (42) of the first (36) and second lever arm (38) can be pivoted beyond its dead center for self-locking. 4. Connection terminal according to one of the preceding claims, characterized in that the housing (10) has an opening (58) for a clamping tool in the region of the pivotable connection (42), in order to pivot the lever arms (36, 38) against each other and thereby tension the clamping spring (20). 5. Connection terminal according to one of claims 1 to 3, characterized in that the housing (10) has an opening (58) in the region of the pivotable connection (42) for a clamping device (60) which can be actuated from outside the housing (10), which is slidably mounted in the housing (10) and is firmly connected to the housing (10). 6. Terminal according to claim 5,
characterized, that the tensioning device (60) is operatively connected to at least one lever arm (3 6; 38) in order to cause the clamping spring (20) to be relaxed. 7. Connection terminal according to one of the preceding claims, characterized in that at least one of the lever arms (36; 38) is connected to an actuating device (54) with which a tensioning and/or relaxing of the clamping spring (20) can be effected. 8. Connection terminal according to claim 7, characterized in that the actuating device (54) can only be actuated when the clamping spring (20) is in the tensioned state. 9. Connection terminal according to claim 7 or 8, characterized in that the actuating device (54) extends out from a first housing side (13) and is guided at least partially around the housing (10) in such a way that it is visible and actuatable from another housing side (11). 10. Connection terminal according to one of the preceding claims, characterized in that the first lever arm (36) is pivotally connected to the second lever arm (38) via a pin (42) or a rivet. 11. Connection terminal according to one of claims 1 to 9, characterized in that the first lever arm (36) and the second lever arm (38) are formed in one piece. 12. Connection terminal according to claim 11, characterized in that the first (36) and second lever arm (36) are pivotally connected to one another via a constriction (66). 13. Connection terminal according to one of the preceding claims, characterized in that it has a limitation (48) for the spring travel of the spring leg (24).