DE20106525U1 - Terminal block with cutting contacts and contact actuators - Google Patents

Description

The invention relates to a terminal block with
an insulating housing,

at least one connection device arranged in the insulating housing for at least one electrical conductor, which has at least one conductor wire and an insulation surrounding the conductor wire, wherein the connection device has a contact spring with a contact blade for separating the insulation of the electrical conductor and a contacting area for contacting the at least one conductor wire,
at least one contact actuating piece which is displaceably guided in the insulating material housing and which has at least one lateral guide means which cooperates with corresponding lateral guide means in the insulating material housing.

A terminal block with a connection device that penetrates the conductor insulation is known from DE 196 27 209. The connection device shown in this document

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¹ Registration text dated 10.04.2001 Page 2

The device has contact blades with cutting edges that expand to form contact surfaces. The contact surfaces enable a larger-area contact to be made with the line wire of the connected electrical conductor than the actual contact blades for separating the conductor, which essentially touch the conductor in a "linear" manner.

The solution of DE 197 32 182 Cl has proven to be effective for supporting the external springing of the connection devices. This document discloses, among other things, an insulation displacement contact with a contact spring with two springy contact legs that delimit a contact slot, with a U-shaped force spring being provided which has essentially flat spring legs. The U-shaped force or overspring is designed as a component separate from the actual contact spring. The essentially plate-shaped spring legs are aligned approximately or essentially perpendicular to the insulation displacement or contacting areas of the contact legs and encompass them along the contact slot over a predetermined width.

A series terminal of this type is known from EP 0 936 697 A1. In this prior art, the contact springs are each formed at the two ends of a busbar, which is aligned in the insulating housing in such a way that the insertion openings of the two contact springs face away from each other, i.e. a conductor is inserted into the contact springs from the outside relative to the support rail. In order to facilitate the actual insertion of the conductors into the contact springs, contact actuating pieces are provided, which are arranged on the top of the insulating housing. The contact actuating pieces are designed like sliders and are inserted into the insulating housing from the outside during initial assembly. They each have a conductor insertion opening and, under a substantially U-shaped recess in the base area, lateral driving surfaces and a depth stop for the conductor.

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LOESENBECK · STRACKE · SPECHT · DANTZ - PATENT ATTORNEYS - EUROPEAN PATENT AND TRADEMARK ATTORNEYS

Registration text dated 10.04.2001

In the upper opening area of the insulating housing, dovetail-like guides are formed on which the contact actuating piece is slidably guided with corresponding dovetail grooves on both sides. The contact actuating piece can be moved between a conductor insertion position and a contacting position using an actuating tool, with these two positions being defined by a locking position.

This terminal block has proven itself to be effective. However, for various applications it is desirable to further develop the design of the terminal block so that terminal blocks with particularly small dimensions can be produced. The solution to this problem is the aim of the invention.

The invention solves this problem through the subject matter of claim 1. The guide means of the contact actuating piece are designed as lateral guide pins which engage in guide grooves in the insulating material housing, the guide pins and the guide grooves being coordinated with one another in such a way that the guide pins can be pivoted and displaced in the guide grooves, so that the guide pins can be displaced in the sense of a superimposed pivoting and/or pendulum movement and a linear and/or curved movement in the guide grooves. The combined pivoting and linear and/or curved movement of the contact actuating pieces allows the length of the guide grooves in the insulating material housing to be shortened compared to simply moving the contact actuating pieces. In addition, tilting is particularly effectively avoided. The guide grooves are preferably designed as straight or curved elongated holes in the walls of the insulating material housing.

According to a further advantageous embodiment of the invention, which can also be considered independently of the subject matter of claim 1, the contact springs

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Registration text dated 10.04.2001 Page 4

of the two connection devices in the terminal housing to each other and the contact actuating pieces are arranged between the contact springs. Essentially only pressure forces act when switching on and off.

According to further variants of the invention, the pins have a circular cross-section or a cross-section that is flattened compared to a circular shape. The geometry of the pins with a cross-section that is flattened compared to the circular shape allows the pivoting of the contact actuating pieces to be limited to a predeterminable angle.

According to a further variant, which can also be considered independently, the actuating piece has at least one, preferably two, lateral openings facing the inner walls of the insulating housing in the area where it engages with the insulating housing, so that the conductor to be wired can extend essentially to the inner wall of the insulating housing. This measure makes it possible to achieve a narrower design in a decisive way, i.e. relatively wide conductors can also be wired using a relatively narrow terminal block. If, on the other hand, the actuating piece encloses the conductor all around, the width of the walls of the actuating piece is lost.

Further advantageous embodiments can be found in the remaining subclaims.

In the following, embodiments of the invention are described in more detail with reference to the drawing. It shows:

Fig. la-e the insertion of a conductor into the connection device of a terminal block according to the invention in five consecutive steps; and

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Registration text dated 11.04.2001 Page 5

Fig. 2a-c show the process of releasing the conductor from the terminals of the terminal block of Fig. 1 in three steps;

Fig. 3a-c a sliding piece for the terminal block from Fig. 1 and 2;

Fig. 4, 5 a further side view and an exploded view of a terminal block according to the invention;

Fig. 6 and 7 the switching and unswitching of a third terminal block;

Fig. 9 is a view of a part of a fourth terminal block of the invention with

cutting connections;

Fig. 10 is a perspective view of a cutting connection of the terminal block

me from Fig. 9 together with contact actuating piece;

Fig. 11 is a section perpendicular to Fig. 9 through the upper part of the clamp

housing and the contact actuator; and

Fig. 12 is a view of a fifth terminal block with insulation displacement connections.

Fig. 1 shows a series terminal 2 - here a feed-through terminal - with a one-piece insulating housing 4 made of plastic, which has in its lower area in Fig. 1 locking feet 6, 8 for locking the series terminal onto a support rail - not shown here - and in its upper area two connection devices 10, 12 for contacting electrical conductors. The connection devices 10, 12 are directly connected to one another via a busbar 14, the ends of which are initially bent upwards at a right angle and then at a right angle to one another. The ends of the busbar thus point towards the center of the terminal or towards one another and each form a kind of sideways "U".

In alternative embodiments, it is also conceivable to design the busbar 14 in several parts and/or to connect electronic components between the connection devices 10, 12 in order to realize further terminal variants.

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Registration text dated 10.04.2001 Page 6

The connection devices 10, 12 are each designed using so-called IDC technology. They each comprise a contact spring 15 at the slotted ends of the busbar 14 that face each other. These each have a contact blade 16 that widens out like a mouth and is also slotted, and a contacting area 20 that is offset relative to the contact blade 16 along the slot 18 of the busbar 14, whereby the contact blade 16 and the contacting area 20 of the busbar 14 can be made in one piece from a uniform material or in multiple pieces, e.g. from two different materials, whereby the different materials are specially adapted to the functions of cutting (e.g. steel cutting) and contacting (e.g. copper).

If a conductor is inserted into the busbar 14, which is slotted at its ends, the insulation of the conductor is first severed by the contact blades 16 and then expanded slightly as the conductor is pushed in further. The contact areas 20 of the contact spring are then pressed against the conductor wires of the conductor 36 (see Fig. 1b).

The contact springs 15 are enclosed in the contacting area 20 by a force spring 22 which is essentially U-shaped in cross section.

According to the teaching of DE 197 32 182 Cl, the force spring 22 has essentially flat spring legs 24, wherein the essentially flat spring legs 24 run essentially perpendicular to the contact edge 16 and the contacting area 20 and encompass them along the contacting area 20.

In a further development of the above-mentioned document, the U-shaped end region of the busbar 14 is supported by the force springs 22 not only in the area of the contact spring 15, which forms one longitudinal leg of the "U", but also in the area of the lower

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Registration text dated 10.04.2001 Page 7

The longitudinal legs of the U-shaped force spring 22 thus enclose the longitudinal legs of the lying "U" which forms the busbar 14 in each of its end regions.

This design offers the particular advantage of reducing the forces introduced into the insulating housing 4 or the terminal carrier during wiring.

In contrast to the solution of EP 0 936 697 A1, the clever space-saving arrangement of the ends of the busbar 14 facing each other or inwards towards the support rail also makes it possible to insert the conductors into the contact edges 14 and the contacting areas 20 from "inside to outside" relative to the support rail, which makes it possible to reduce the width of the terminal block on both sides of the support rail compared to EP 0 926 697.

The conductor is inserted into the contact springs 15 with the aid of a contact actuating piece 26 which is slidably guided and also pivotally mounted in the insulating material housing. Actuation with a contact actuating piece 26 is already known from EP 0 926 697. However, unlike in this document, in the series terminal of Fig. 1, it is possible to arrange the contact actuating pieces 26 between the contact springs 15 - i.e. towards the terminal center - by aligning the ends of the busbar with the contact edges facing each other towards the "terminal center".

During initial assembly, the contact actuating pieces 26 are each inserted from above into openings 28 of the preferably one-piece insulating housing 4 and are guided there so as to be displaceable essentially parallel to the contact springs 15.

The contact actuating pieces 26 have in the side view of Fig. 1 or 3a a direction extending in the broadest sense from "top" to "bottom", i.e. in the direction of the mounting rail

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Registration text dated 10.04.2001 Page 8

widening, e.g. "pear-like" shape and are penetrated by an insertion hole 34 for the conductor 36 (see Fig. 1b). They protrude slightly upwards from the opening 28 out of the insulating housing 4 so that their respective switching position in the insulating housing 4 can be seen from the outside, which makes it easier to insert the conductor 36.

In their area facing the contact edge 16, they are also provided with a recess 38. They also have a conductor contact surface 39 and a receptacle 40 for the contact edge 16 after the conductor insulation has been severed, which is shaped such that it essentially reproduces the shape of the contact edges for reasons of strength.

The function of this arrangement becomes clear with regard to the switching on of the terminal block from Fig. 1a-e and with regard to the switching off of the terminal block 4 from Fig. 2a-c.

First, a conductor (not shown in Fig. 1a) is inserted into the opening 34 of the contact actuating piece 26. According to Fig. 1a, it is possible to insert an actuating tool 42 into the insulating housing on the side of the contact actuating pieces 26 facing away from the contacting area 16 into the openings 28 of the insulating housing 4 between the insulating housing 4 and the contact actuating piece 26. The actuating tool 42 thereby encounters a guide bevel 44 in the insulating housing and pushes the contact actuating piece 26 (see Fig. 1b) with the conductor inserted therein in the direction of the contact cutting edge 16, wherein the contact actuating piece - see Fig. 1b - is first pivoted slightly on its guide pin 30 and then displaced further in the guide groove 32 by performing a combined rotary and linear movement.

If the operating tool 42 is inserted further into the opening 28, it finally comes into contact with the busbar 14 (see Fig. Ic).

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Registration text dated 10.04.2001 Page 9

it is pivoted on the busbar 14 in the direction of the connection device 10 or 12 (see Fig. Id and Ie).

When the actuating tool 42 moves, the conductor insulation is severed by the contact blades and widened when the conductor 36 is pushed further into the slot 18 until the contact actuating piece 26 with the conductor inserted therein, as shown in Fig. 1e, with the receptacle 40, engages over the contact blades 16, the conductor wire(s) of the conductor 36 contacting the contacting areas 20 of the connecting devices 10, 12.
10

Fig. 2a-c show the disconnection of the terminal block of Fig. 1.

When switching off, the actuating tool 42 is inserted into the opening 28 of the insulating housing 4 on the side of the contact actuating piece 26 which is located on the outside relative to the mounting rail or terminal center (plane K) (Fig. 2a) until it comes to rest on a stop 46 of the contact actuating piece 26 which protects the metal parts of the contact spring 15.

The contact actuating piece 26 is then moved with the actuating tool 42 towards the terminal centre or in the direction of the mounting rail (Fig. 2b).

The contact actuating piece 26 pulls the conductor 36 out of the contacting area 20 from the contact spring 15 until it finally slides past the contact cutting edge 16 out of the contact spring into the position shown in Fig. 2c, in which the conductor 36 can be pulled upwards out of the contact actuating piece 26.

Further advantages of the invention result directly from the above explanations of the switching on and off of the terminal block.

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Registration text dated 10.04.2001 Page 10

The guidance of the contact actuating piece 26 in the manner of a superimposed rotary or pendulum and a linear movement with the guide pins 30 in the guide grooves 32 particularly reliably prevents the contact actuating pieces 26 from tilting when the terminal block is switched on and off. In addition, it is possible to make the guide grooves 32 shorter than would be conceivable with a purely linear movement of the contact actuating pieces 26 in the guide grooves 32. In particular, when the guide grooves 32 are designed as elongated holes (possibly also curved), it is advantageous that the length can be shortened compared to when the contact actuating pieces are designed as elements that can be moved alone, since this increases the stability of the insulating housing in this area compared to a receiving groove with a length that is necessary for a purely linear guide.

A taper 47 in the guide groove 32 divides it into locking positions for the guide pin 30, which are formed on both sides of the taper and into which the guide pin noticeably engages when actuated.

Fig. 3 shows particularly clearly a further advantage of the invention.

According to this, the actuating piece 26 has at least one, preferably two - here on both sides - lateral slot-like openings 54a,b facing the inner walls of the insulating material housing in its lower region 26' engaging in the insulating material housing, so that the conductor to be wired can extend essentially to the inner wall of the insulating material housing. The insulation of the conductor can penetrate these slot-like openings 54a,b. The conductor is only completely enclosed in the upper region 26o, which does not engage in the insulating material housing. This means that conductors with a cross-section that is relatively large in relation to the width can also be inserted with a small grid dimension or a small construction width.

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Registration text dated 10.04.2001 Page 11

Corresponding openings can also be provided in the metallic over- or force spring 22.

This measure makes it possible to achieve a narrower design, i.e. relatively wide conductors can also be connected using a relatively narrow terminal block. If, however, the actuating piece encloses the conductor all the way around, the width of the walls of the actuating piece is lost.

The web 30 does indeed bridge the slot-like openings. However, since the webs 30 fully engage in the guide grooves 32, the conductor can also have at least a diameter in the area of the webs 30 that corresponds to the width of the opening 28 or the distance between the two webs 30.

An alternative design is shown in Fig. 6 and 7. In the terminal block 2 shown in this figure, the contact actuating piece is also provided with lateral guide pins 30, but these are guided in the guide grooves 32 in a purely sliding manner. Such an embodiment is also feasible. It also offers the advantage of arranging the actuating pieces relative to the connection devices 10, 12 towards the center of the terminal. However, the guide grooves 32 must be made somewhat longer than in the embodiment of Fig. 1 and 2.

According to Fig. 6, the stop 46 is further provided with a locking projection 50 which is designed to engage in a recess 52 of the terminal housing 4.

Fig. 8 shows a further advantageous variant of the invention. According to this variant, the actuating piece 26 is guided in an arc-shaped guide groove 32, with the center M of the circular arc of the guide groove 32 lying above the housing. This makes it possible to achieve a narrow design.

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Registration text dated 10.04.2001 Page 12

Preferably, the superimposed swivel and curve movement is also realized here, but the swivel behavior can also be largely minimized in less preferred variants - as shown in Fig. 8.

In Fig. 8, the U of the busbar 14 is also particularly narrow, but extends beyond the rear area of the force spring 22, with the busbar 14 being supported in the rear area of the U, i.e. in the area of the base leg in the insulating housing. The busbar 14 is also supported on an abutment W in the overspring 22.

In the embodiment of Fig. 9, the contact actuating piece 26 is guided essentially linearly in the guide grooves 32. As can be seen in Fig. 10, the contact actuating piece 26 and the insulating housing 4 engage in one another in the upper area by means of a dovetail connection 55, i.e. the upper edges of the webs 30 of the contact actuating pieces 26 and the lower edges of the upper section 26o of the contact actuating piece and the associated sections of the insulating housing 2 are provided with corresponding guide slopes 56a, b, 58a, b. This ensures a secure linear guidance of the guide piece even when a torque is applied by moving the screwdriver.

Another difference between the embodiment in Fig. 9 and that in Fig. 1 lies in the spring geometry and its arrangement. Unlike in Fig. 1, the busbar does not run in a U-shape inside the force spring 22, but rather it first passes through the force spring 22 in the contact area 20, then runs outside the force spring 22 in the direction of the support rail 60 vertically downwards and finally turns away from the force spring 22 vertically, so that the busbar in the view in Fig. 10 essentially has a Z-like geometry in the area of the force spring. The lower leg of the Z is used to mount the busbar 14 on another busbar 62.

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which connects the various connection devices 10, 12 or their busbar pieces 14 with each other.

As can be seen in Fig. 11, more than two (here three, but conceivably also four or more) connection devices 10, 12 can be attached to the busbar 62 if the insulating housing is widened accordingly.

According to Fig. 9 and 11, the force spring 22 is provided with a projection 64 on its side facing the contact edge 16 in the area of the lower corner relative to the support rail, which projection engages under an abutment 66 in the insulating housing. Since the busbar 14 and the busbar 62 together engage under another abutment 67 in the insulating housing and since further sides of the force spring 22 also rest against walls of the insulating housing, a defined seat of the force spring 22 in the insulating housing 2 is ensured.

In the embodiment of Fig. 9 and 11, a conductor (not shown) is also inserted into the opening 34 of the contact actuating piece 26. It is again possible to insert an actuating tool 42 into the insulating housing on the side of the contact actuating pieces 26 facing away from the contacting area 16 into the openings 28 of the insulating housing 4 between the insulating housing 4 and the contact actuating piece 26. The actuating tool 42 then hits a guide bevel 44 in the insulating housing and pushes the contact actuating piece 26 with the conductor inserted therein in the direction of the contact cutting edge 16, whereby the contact actuating piece is displaced further in the guide groove 32 while performing a linear movement.

If the operating tool 42 is inserted further into the opening 28, it finally comes into contact with, for example, the busbar 14. It is then

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Registration text dated 10.04.2001 Page 14

Busbar 14 or a housing stop is pivoted in the direction of the connection device 10 or 12.

When disconnecting, the actuating tool 42 is inserted into the opening 28 of the insulating housing 4 on the side of the contact actuating piece 26 that is on the outside relative to the mounting rail or terminal center (level K) until it comes to rest on a stop 68 of the insulating housing that protects the metal parts of the contact spring 15, on which the contact actuating piece 26 is moved "like a rail" with the actuating tool 42 towards the terminal center or in the direction of the mounting rail. It should also be emphasized that disconnecting is also possible if the screwdriver is not placed on the stop 68 to the left as shown in the left part of Fig. 9, but pivoted to the right and then pivoted to the left. The stop 68 or another attachment in the insulating housing not shown here can also be designed in such a way that protection is provided to prevent the conductor from being misconnected when it is inserted into the terminal block.

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Registration text dated 10.04.2001 Page

Reference symbol Terminal block 2 Insulated housing 4 Locking feet 6.8 Connection devices 10.12 Busbar 14 Contact spring 15 Contact cutting edge 16 Slot 18 Contact area 20 Power spring 22 Spring leg 24 Contact actuator 26 openings 28 Guide pin 30 Guide groove 32 Insertion hole 34 Director 36 Recess 38 Conductor contact surface 39 Recording 40 Operating tool 42 Guide bevel 44 attack 46 rejuvenation 47 Support rail 48 Locking projection 50 Recess 52 openings 54 Dovetail joint 55 Guide bevels 56a, b, 58 a, b Support rail 60 Busbar 62 head Start 64 Abutment 66 Abutment 67 attack 68 Middle level K Abutment W

Claims (21)

1. Terminal block, with a) an insulating housing ( 4 ), b) at least one connecting device ( 10 , 12 ) arranged in the insulating housing ( 4 ) for at least one electrical conductor ( 36 ) which has at least one conductor wire and an insulation surrounding the conductor wire, the connecting device ( 10 , 12 ) having a contact spring ( 15 ) with a contact blade ( 16 ) for separating the insulation of the electrical conductor and a contacting area ( 20 ) for contacting the at least one conductor wire, c) at least one contact actuating piece ( 26 ) which is displaceably guided in the insulating housing ( 4 ) and which has at least one lateral guide means ( 30 ) which cooperates with corresponding lateral guide means ( 32 ) in the insulating housing, characterized in that a) the guide means of the contact actuating piece ( 26 ) are designed as lateral guide pins ( 30 ) which engage in guide grooves ( 32 ) of the insulating housing ( 4 ), the guide pins ( 30 ) and the guide grooves ( 32 ) being coordinated with one another in such a way that the guide pins ( 30 ) can be pivoted and displaced in the guide grooves ( 32 ), so that the guide pins ( 30 ) can be displaced in the sense of a superimposed pivoting and/or pendulum movement and a linear and/or curved movement in the guide grooves ( 32 ). 2. Terminal block according to claim 1, characterized in that the guide grooves ( 32 ) are designed as straight or curved elongated holes in the walls of the insulating housing ( 4 ). 3. Terminal block according to the preamble of claim 1 or according to claim 1 or 2, characterized in that the contact springs ( 15 ) of the two connection devices ( 10 , 12 ) in the terminal housing ( 4 ) point towards each other and that the contact actuating pieces ( 26 ) are arranged between the contact springs ( 15 ). 4. Terminal block according to one of the preceding claims, characterized in that the pins ( 30 ) have a circular cross-section or a cross-section that is flattened compared to a circular shape. 5. Terminal block according to one of the preceding claims, characterized in that the contact actuating pieces ( 26 ) can each be inserted during initial assembly from above into openings ( 28 ) of the preferably one-piece insulating housing ( 4 ). 6. Terminal block according to one of the preceding claims, characterized in that the contact actuating pieces ( 26 ) have a shape which widens in sections in the direction of the locking feet ( 6 , 8 ) and are penetrated by an insertion bore ( 34 ) for the conductor ( 36 ). 7. Terminal block according to one of the preceding claims, characterized in that the contact actuating pieces ( 26 ) protrude slightly upwards from the opening ( 28 ) out of the insulating housing ( 4 ). 8. Terminal block according to one of the preceding claims, characterized in that the contact actuating pieces ( 26 ) are provided with a recess ( 38 ) in their region facing the contact cutting edge ( 16 ) and have a conductor contact surface ( 39 ) and a receptacle ( 40 ) for the contact cutting edge ( 16 ), which is shaped such that it essentially reproduces the shape of the contact cutting edge. 9. Terminal block according to one of the preceding claims, characterized in that the openings ( 28 ) in the insulating housing are designed such that an actuating tool ( 42 ) can be guided in the opening ( 28 ) between the insulating housing ( 4 ) and the contact actuating piece ( 26 ). 10. Terminal block according to one of the preceding claims, characterized in that the insulating housing ( 4 ) is provided with a guide bevel ( 44 ) for the operating tool ( 42 ). 11. Terminal block according to one of the preceding claims, characterized in that the opening ( 28 ) in the insulating housing ( 4 ) preferably extends to the busbar ( 14 ). 12. Terminal block according to one of the preceding claims, characterized in that the contact actuating piece ( 26 ) is provided on its side lying outside relative to the terminal center (plane K) with a stop ( 46 ) for positioning the actuating tool ( 42 ) during disconnection. 13. Terminal block according to one of the preceding claims, characterized in that the stop ( 46 ) is provided with a locking projection ( 50 ) which is designed for locking engagement in a recess ( 52 ) of the terminal housing ( 4 ). 14. Terminal block according to one of the preceding claims, characterized in that a taper ( 47 ) is formed in the guide groove ( 32 ), which divides it into locking positions for the guide pin ( 30 ). 15. Terminal block according to one of the preceding claims, characterized in that the contact springs ( 15 ) are each provided with a force spring ( 22 ) with a U-shaped cross section. 16. Terminal block according to one of the preceding claims or according to the preamble of claim 1, characterized in that the actuating piece ( 26 ) has, in its region engaging in the insulating housing, at least one, preferably two lateral openings ( 54 ) facing the inner walls of the insulating housing, so that the conductor to be wired can extend substantially as far as the inner wall of the insulating housing. 17. Terminal block according to one of the preceding claims, characterized in that the contact actuating piece ( 26 ) and the insulating housing ( 4 ) engage with one another in the upper region by means of at least one dovetail connection ( 55 ). 18. Terminal block according to one of the preceding claims, characterized in that, in order to form the dovetail connection ( 55 ), the upper edges of the webs ( 30 ) of the contact actuating pieces ( 26 ) engaging in the guide grooves ( 32 ) and the lower edges of the upper section ( 260 ) of the contact actuating piece as well as the associated sections of the insulating housing ( 2 ) are provided with guide slopes (56a, b; 58a, b) corresponding to one another. 19. Terminal block according to one of the preceding claims, characterized in that the force spring ( 22 ) is provided on its side facing the contact edge ( 16 ) in the region of the lower corner relative to the support rail with a projection ( 64 ) which engages under an abutment ( 66 ) in the insulating housing ( 2 ). 20. Terminal block according to one of the preceding claims, characterized in that the insulating housing ( 4 ) has a stop ( 68 ) protecting the metal parts of the contact spring ( 15 ), on which the contact actuating piece ( 26 ) with the actuating tool 42 can be displaced towards the terminal center or in the direction of the support rail. 21. Terminal block according to one of the preceding claims, characterized in that a projection to prevent mismating is formed in the insulating housing.