DE102021105362A1 - Front screw terminal - Google Patents

Abstract

The invention relates to a front screw terminal (10) for connecting an electrical conductor (70), having a conductor connection area (11), an electrically conductive contact element, a clamping screw (40), a return spring (60) and a clamping pocket (30) which a pressure piece (50) is pivotably mounted in a bearing point (16). The pressure piece (50) can be pivoted in the direction of the conductor connection area (11) by actuating the clamping screw (40) against the spring force of the return spring (60) and for clamping a conductor (70) inserted into the conductor connection area (11) between the pressure piece (50). and formed the electrically conductive contact element. The clamping pocket (30) has an assembly opening (15) through which the pressure piece (50) is introduced into the clamping pocket (30) during assembly and is fed to the bearing point (16). The clamping screw (40) lies between the conductor connection area (11) and this mounting opening (15).

Description

The invention relates to a front screw terminal for connecting an electrical conductor according to the preamble of claim 1.

In the field of electrical connection technology, front screw terminals are known in which an electrical conductor is fed in from the same direction as the actuation of a clamping screw, i.e. essentially on the same side of a terminal. There are different versions of such front screw terminals that implement the same operating principle in different ways. The torque introduced by a screw is converted into a clamping force by means of a displaceable pressure piece or clamping body, which presses the conductor to be connected onto an electrically conductive metal part and thus fixes it in an electrically conductive manner. In particular, the design and mounting of the pressure piece and the arrangement of the clamping screw in relation to the pressure piece can vary.

For example, front screw terminals are known in which the pressure piece consists of a cold-formed metal part, such as the DE 93 177 83 U1 or the EP 0 271 594 A1 describe. For this purpose, the contours for a clamping area and a mounting of the pressure piece are stamped on the metal part. Furthermore, front screw terminals are known in which the assembly of the pressure piece in a terminal space is very complex. Often a U-shaped or closed metal pocket is used as the clamping space, which is formed from several bent tabs, and the bending sequence required to produce the metal pocket is complex. The formation of a bearing point for the pressure piece can also be difficult, depending on the design. In the case of many front screw terminals, the bearing point is, for example, between a wall of a clamping pocket through which the clamping screw is threaded and a conductor entry area. This wall of a clamping pocket or the complete clamping pocket must first be finished bent, so that the pressure piece can then often only be threaded into the bearing point with great effort, as is the case, for example, with the embodiment which the DE 93 177 83 U1 describes.

In other embodiments, a pressure piece has to be pressed into a finished bent clamping pocket until the position of the bearing point is reached, which leads to a disadvantageous mechanical load on the clamping pocket and the pressure piece. This also increases the assembly costs. Such an embodiment are disclosed, for example, by the EP 0 271 564 A1 or the DE 10 2008 010 162 A1 . Other front screw terminals have an additional axis or shaft for mounting the pressure piece, as is the case, for example, in the DE 10 2004 021 836 B4 is described. Although this design simplifies the assembly of the pressure piece in a clamping pocket, it increases the part costs. Also known are front screw terminals in which the screw position and the bearing point are arranged unfavorably with respect to one another. Often the clamping screw is screwed in as a wedge between the metal pocket and the pressure piece, which can lead to a deformation of the screw thread and thus to the system becoming stiff. This is the case, for example, in embodiments as shown in FIG EP 0 271 594 A1 or the DE 10 2004 010 579 B4 are known.

Furthermore, the EP 3 525 289 A1 a front screw terminal with a cam-shaped pressure piece which can be pressed against an electrically conductive contact element by actuating a clamping screw against the spring force of a return spring. This contact element is formed by a separate, angled metal part, which can be inserted with a first leg into a clamping pocket made of non-conductive material, the second arm largely closing an open side of the clamping pocket. Before attaching this angular contact element, the pressure piece can be introduced into the clamping pocket via the initially open side and pushed into bearing receptacles that are located on this side of the clamping pocket. The return spring is also supported on the contact element. Thus, the pressure piece can indeed be assembled with the contact element and the spring, but this design also requires an increased assembly effort.

The invention is based on the object of providing a front screw terminal with a pressure piece and a return spring, with which the disadvantages mentioned can be avoided.

This object is achieved by a front screw terminal with the features of claim 1. Advantageous further developments of the front screw terminal emerge from the subclaims 2-16.

The front screw terminal according to the invention is designed for the connection of an electrical conductor. A front screw terminal is to be understood as a connection terminal in which an electrical conductor is fed in from the same direction as the actuation of a clamping screw. This side of the terminal is referred to as the front side in the following, while the opposite side is referred to as the rear side.

The front screw terminal according to the invention has a conductor connection area and an electrically conductive contact element. One in the Conductor connection area of inserted conductors should be contacted in a terminal space with the electrically conductive contact element by being pressed onto the contact element. The contact element can be designed and arranged in various ways. The front screw terminal also has a clamping screw, a return spring and a clamping pocket. The clamping pocket forms the clamping space. A pressure piece is pivotably mounted in a bearing point on the clamping pocket. The front screw terminal is designed so that the pressure piece can be pivoted in the direction of the conductor connection area by actuating the clamping screw against the spring force of the return spring and is designed to clamp a conductor inserted into the conductor connection area between the pressure piece and the electrically conductive contact element. An actuation of the clamping screw here means a rotation of the clamping screw, by means of which the position of the clamping screw is shifted translationally in the direction of its longitudinal axis. A torque introduced by a clamping screw is converted into a clamping force by means of a displaceable pressure piece, which presses the conductor to be connected onto an electrically conductive metal part and thus fixes it in an electrically conductive manner.

A mounting opening is provided in the clamping pocket, through which the pressure piece is introduced into the clamping pocket during installation of the front screw terminal and is fed to the bearing point. According to the invention, the assembly opening is arranged in such a way that the clamping screw lies between the conductor connection area and the assembly opening.

The invention has the advantage that the assembly opening is on one side of the clamping pocket, which enables a simplified installation of a pressure piece in a clamping pocket. A threaded hole for the clamping screw and a conductor opening for inserting a conductor must be provided on the front of the front screw terminal, which makes this side unsuitable for such a mounting opening. Known assembly openings on the back of the front screw terminal, ie on the side of a clamping pocket which is opposite the threaded hole for the clamping screw and the conductor opening, usually require an increased installation effort, since the relevant bending area of a return spring is often in this area and / or a return spring is even in this area is fixed to the clamping pocket. The assembly of the pressure piece and return spring must therefore be coordinated with one another.

On the other hand, when viewed from the longitudinal axis of the clamping screw opposite the conductor connection area, there is sufficient space at the clamping pocket to provide an assembly opening. The clamping space within the clamping pocket is easily accessible from this side, with the return spring and clamping screw elements being suitably positioned so that they can also be installed in front of the pressure element, but do not block the installation opening afterwards. This is particularly the case when the invention provides in one embodiment that a bending area of the return spring that is elastically deformed when the clamping screw is actuated is located outside the assembly opening. The essential area of a return spring therefore does not block the assembly opening. This distinguishes the front screw terminal according to the invention, for example, from the front screw terminal, which is derived from the EP 3 525 289 A1 is known. In the latter case, the bending area of a return spring blocks a mounting opening for the pressure piece, which means that the pressure piece can only be installed before or at the same time as the return spring.

Furthermore, the invention makes it possible to keep the rear side of the clamping pocket free of an assembly opening, so that this side can be used to attach protruding contact means to the clamping pocket. In addition, the side of the clamping pocket opposite the assembly opening, i.e. the pocket base, can also be used to attach protruding contact means. The contact means are, for example, soldering pins or one or more contact tulips. The clamping pocket is made, for example, of a high-strength copper material (e.g. bronze) and the pocket base represents the contact element to the connection conductor. The contact means can be integrally molded onto the pocket base or connected to the pocket base by a material connection (e.g. welding). One side of the clamping pocket is then reserved for the assembly of the pressure piece, while the back and the underside of the clamping pocket can be reserved for the attachment of a contact means, which reduces the installation effort compared to other solutions.

In one embodiment of the invention, the electrically conductive contact element is formed in one piece by the clamping pocket and does not represent a separate component. It therefore consists of the same electrically conductive material as the clamping pocket. This material is preferably an electrically conductive copper material which is particularly high-strength. For example, a bronze can be used.

The clamping pocket can, however, also be made of a material that is much less electrically conductive than copper. In one embodiment of the invention, the clamping pocket is formed from a steel, for example. To make electrically conductive contact with the conductor then an additional component made of a conductive material (e.g. copper material) is required, which is inserted between the pressure piece and the pocket base. This component then forms the contact element. The contact means can then be formed in one piece on the contact element.

The pressure piece can be manufactured as a metal part with embossed contours. In an alternative embodiment, it is a stamped and bent part which was manufactured from a strip material. The mounting of the pressure piece on the clamping pocket can be designed in different ways. In one embodiment of the invention, the clamping pocket forms, for example, two bearing straps, each with a bearing receptacle. The pressure piece then has two opposite bearing bolts, via which the pressure piece is pivotably mounted between the two bearing straps in the bearing receptacles. These bearing receptacles are preferably designed to be open towards the assembly opening. If the pressure piece is passed through the assembly opening, the bearing bolts can be pushed into the bearing receptacles without the two bearing brackets having to be pushed apart. The bearing receptacles are slots on each edge of a bearing bracket, which can in particular be curved or hook-shaped and thus form bearing indentations at their closed ends. The bearing bolts of the pressure piece are pushed into these end-side bearing indentations during assembly. The shape and position of the bearing indentations is selected in particular so that the pressure piece is held in them in a captive manner. This can be supported by the spring force of the return spring, by means of which the bearing bolts of the pressure piece are pressed into the bearing indentations.

At least one form fit is provided between the bearing pin and the bearing indentations, which prevents movement of the pressure piece in its entirety in the direction of the assembly opening.

This is preferably also the case if the clamping screw has not (yet) been fully installed or has been removed again. In the context of the invention, a clamping screw that is not fully assembled is to be regarded as a clamping screw that was either not screwed in at all or that was screwed into a threaded hole but does not protrude into the interior of the clamping pocket. In one embodiment of the invention, the restoring spring exerts a force on the pressure piece which holds the pressure piece in the bearing location in a captive manner when the clamping screw is not completely installed. The bearing bolts of the pressure piece are pressed into the bearing indentations, for example, as described. This captive holding of the pressure piece can be supported by stops against which other areas of the pressure piece are pressed.

A stop can also be used to hold the pressure piece in a defined open position when the clamping screw is not fully installed. This open position enables the clamping screw to be screwed in (further) without the position of the pressure piece making this difficult or even preventing it completely when it blocks the movement of the clamping screw. It is important in this embodiment that the pressure piece cannot protrude too much into an area within the clamping pocket into which the tip of the clamping screw is screwed. Such a tip is designed, for example, as a rounded pressure pin. A tip of the clamping screw located within the clamping pocket can then be displaced by a screwing movement within an imaginary, cylindrical screw area, and in one embodiment of the invention a stop is provided which, when the clamping screw is not fully installed, limits a movement of the pressure piece into this screw area caused by the return spring . A disadvantageous displacement of the pressure piece in front of the threaded hole for the clamping screw is limited.

Either the stop completely prevents the pressure piece from moving into this screw area of the clamping screw, or the movement is permitted up to a certain position which still allows the clamping screw to be screwed in, for example by the clamping screw pushing the pressure piece away. The pressure piece does not have to be kept completely out of the screw area of the clamping screw; depending on the design, it can be sufficient if certain areas do not slide in front of the threaded hole for the clamping screw. For example, the pressure piece has a pressure area which, when the clamping screw is actuated, presses a conductor introduced into the conductor connection area with a clamping force against the electrically conductive contact element. In one embodiment it is provided that the stop limits the movement of this pressure area of the pressure piece into the screw area of the clamping screw. The pressure area is provided, for example, at the pivotable end of the pressure piece and such a pressure area pivoted in front of the threaded hole for the clamping screw can completely block the access for the clamping screw, since it may not be affected by the clamping screw due to the rest of the geometry of the pressure piece and its bearing point on the clamping pocket can be pushed away.

At least one wall of the clamping lug has a threaded bore into which the clamping screw is screwed. In one embodiment of the invention, the previously described stop for the pressure piece is formed by such a wall. The wall runs essentially at an angle of approximately 90 ° to the longitudinal axis of the clamping screw and the pressure piece can strike the wall from different directions. For example, the pressure piece, in particular the pressure area of the pressure piece, strikes the stop transversely to the longitudinal axis of the clamping screw. The pressure piece then hits an edge of the wall. The position of the edge defines the open position of the pressure piece and is selected accordingly. In this way, a stop can be provided for the stated purpose in a simple and effective manner.

In one embodiment of the invention, the pressure piece is angled, spanning an obtuse angle towards the conductor connection area, i.e. it angles towards the clamping screw. One end of the pressure piece is held on the clamping pocket via the bearing point and the opposite end can be pivoted about the bearing point. The return spring is formed, for example, by a simply bent spring steel that is fixed at one end. This end is preferably fixed to the clamping pocket. The other end is free to move and there is a bending area between the two ends. When the free end of the return spring is deflected, the bending area generates a spring force in the opposite direction.

The simply curved return spring is a very simple spring that is easy to manufacture and easy to assemble. The return spring is arranged in such a way that its free end makes contact with the pressure piece on the side facing away from the clamping screw. It is also designed in such a way that it exerts a spring force in the direction of the clamping screw, i.e. away from the conductor connection area, on the pressure piece. If the pressure piece is pressed by the clamping screw in the direction of the conductor connection area, the curved return spring is expanded and the spring force applied to the pressure piece increases further.

The return spring is arranged, for example, in such a way that the bearing point of the pressure piece is received by the return spring. The bearing point is then within the bend of the return spring. This allows a space-saving arrangement of the pressure piece and return spring. Furthermore, the bearing point of the pressure piece can be arranged near the fixed end of the return spring. Not only can the bearing point of the pressure piece lie within the bend of the return spring, but also other areas of the pressure piece.

The clamping pocket is suitably shaped to hold at least the clamping screw, the pressure piece and the return spring. In one embodiment of the invention, it is a stamped and bent part which has a U-shaped curved base body with a pocket base from which two bearing straps extend at right angles and run parallel to one another. The clamping area of the clamping pocket lies between these two bearing brackets. The conductor connection area lies in the area of the pocket base and an inserted conductor can be pressed against the pocket base by the pressure piece, whereby the pocket base forms the electrically conductive contact element according to the invention. The pressure piece is pivotably mounted between the bearing tabs extending from the pocket base and the bearing receptacles described with the bearing indentations are formed on these bearing tabs. The bottom of the pocket is opposite the assembly opening, which is formed on this side at least by the edges of the bearing tabs, which form a groove or a gap. The bearing receptacles are formed on this side, for example, as open slots in the edges of the bearing brackets. Starting from the respective edge, they initially run in the direction of the bottom of the pocket and then bend towards the back of the clamping pocket. They preferably run a little further back in the direction of the edge in order to form a bearing indentation at their end. The bearing receptacles are preferably stamped into the bearing brackets.

In one embodiment, at least one threaded bracket, into which the clamping screw is screwed, extends at right angles from the bearing brackets. The threaded bracket extends from one side of a bearing bracket that runs at right angles to the depth base, so that the threaded bracket also runs at right angles to the depth base. The threaded flap is on the front of the clamping pocket. In order to hold the clamping screw better and to prevent unwanted deformation of the clamping pocket, it can be provided that two threaded brackets extend at right angles from the bearing brackets, which at least partially overlap, and the clamping screw is screwed into both threaded brackets in the overlap area. For example, a first threaded bracket, into which a threaded hole is made, extends from one bearing bracket, and a second threaded bracket, into which a second threaded bore is made, extends in the opposite direction from the other bearing bracket. The threaded bores are aligned with one another in an overlapping area of the threaded brackets, so that the clamping screw can be screwed through both threaded bores.

The at least one threaded flap protrudes so far in the direction of the pocket base that between it and an opening remains in the bottom of the pocket through which a conductor can be inserted into the clamping pocket. That edge of the at least one threaded flap that points towards the bottom of the pocket can also form a stop for the pressure piece. By actuating the clamping screw, the pressure piece is pressed away from the edge towards the bottom of the pocket.

In a further embodiment of the invention, a push-through protective flap extends at right angles from at least one bearing flap and delimits the conductor connection area in the plug-in direction of the conductor. This reduces the insertion depth of the conductor, but protruding contact means such as soldering pins and / or contact tulips can also be attached to this push-through protection tab. The push-through protection flap runs at right angles to the bottom of the pocket and goes from the side of a bearing flap which is on the back of the clamping pocket. It partially or completely closes the back of the clamping pocket.

In one embodiment of the invention, a spring tab is formed on the clamping pocket, to which the return spring is fixed. It is fastened, for example, by riveting or welding. For example, the spring tab is on the side of the assembly opening and extends from a bearing tab. The spring tab then runs essentially parallel to the bottom of the pocket and closes part of the gap that is formed on this side between the edges of the two bearing tabs. The assembly opening is then limited, for example, by the bearing tabs, the spring tab and the at least one threaded tab. A preferably rectangular assembly opening is thus formed, the size of which is sufficient to insert the pressure piece through the assembly opening and bring it into its desired position within the clamping pocket.

The clamping pocket with the functional components built into it is preferably arranged in an insulating housing made of an electrically insulating material. The insulating housing has at least two openings to allow access to the clamping pocket. A conductor opening is used to introduce a conductor through the insulating housing into the conductor connection area of the terminal pocket. Another screw opening is used to feed the clamping screw into the clamping pocket. Since these two openings are next to each other on the front side of the clamp, the two openings can also be combined to form a common opening.

In one embodiment of the invention, the insulating housing then covers the assembly opening. The advantageous arrangement of the mounting opening according to the invention also comes into play when shaping the insulating housing, since the rear side of the insulating housing can have a larger opening through which the entire clamping pocket can be pushed into the insulating housing after the return spring and the pressure piece have been assembled. This simple insertion of the clamping pocket takes place in the direction of the longitudinal axis of the clamping screw or the direction of insertion of the conductor. This is particularly advantageous if contact means such as soldering pins or a contact tulip are attached to the rear of the clamping pocket. The larger insertion opening on the back of the insulating housing can then be closed with a cover or another housing part, for example. Indentations or projections on the front side of the clamping pocket can also engage in indentations or projections on the inside of the front side of the insulating housing and the clamping pocket is thus securely held transversely to the longitudinal axis of the clamping screw.

Further advantages, special features and expedient developments of the invention emerge from the subclaims and the following illustration of preferred exemplary embodiments on the basis of the figures.

• 1 einen schematischen Schnitt durch eine erste Ausführungsform einer Frontschraubklemme mit Löt-stiften in einer ersten Ausrichtung;
• 2 einen schematischen Schnitt durch eine zweite Ausführungsform einer Frontschraubklemme mit Löt-stiften in einer zweiten Ausrichtung;
• 3 einen schematischen Schnitt durch eine dritte Ausführungsform einer Frontschraubklemme als Steckerausführung mit einer Kontakttulpe;
• 4 eine dreidimensionale Ansicht einer Klemmtasche;
• 5 eine dreidimensionale Ansicht eines Druckstücks;
• 6 eine Frontschraubklemme gemäß 1 mit kontaktiertem Leiter;
• 7 eine dreidimensionale Ansicht einer Klemmtasche mit kontaktiertem Leiter; und
• 8 einen schematischen Schnitt durch eine Frontschraubklemme gemäß 1 ohne montierte Klemmschraube.

Show it

• 1 a schematic section through a first embodiment of a front screw terminal with soldering pins in a first orientation;
• 2 a schematic section through a second embodiment of a front screw terminal with soldering pins in a second orientation;
• 3 a schematic section through a third embodiment of a front screw terminal as a plug design with a contact tulip;
• 4th a three-dimensional view of a clamping pocket;
• 5 a three-dimensional view of a pressure piece;
• 6th a front screw terminal according to 1 with contacted conductor;
• 7th a three-dimensional view of a clamping pocket with a contacted conductor; and
• 8th a schematic section through a front screw terminal according to 1 without installed clamping screw.

the 1 until 3 show different embodiments of front screw terminals according to the invention 10 , 10 ' and 10 " which differ only in the type or arrangement of a protruding contact means. For example, have contact means in the form of solder pins 12th and 13th at the embodiment of the 1 a first alignment in which the solder pins 12th , 13th essentially at right angles to the direction of movement of a clamping screw 40 stick out. They are on one side of the front screw terminal 10 attached to a mounting opening 15th opposite, ie in the area of a conductor connection area 11 .

In the embodiment of 2 loosening pins run 12th , 13th however, in the direction of movement of a clamping screw 40 . They stand from the back of the front screw terminal 10 ' away. In the embodiment of 3 is a contact tulip as a contact means 14th provided in a housing part 23 and together with this from the rear of the front screw terminal 10 " sticks out. The rest of the structure is identical in all embodiments, so that this can be seen in the following on the basis of FIG 1 is explained, but in an analogous manner for the embodiments of FIG 2 and 3 is applicable. In the 1 until 3 the front of a front screw terminal is on the left, while the back is on the right.

A front screw terminal 10 ( 10 ' , 10 " ) has a clamping pocket 30th which is formed by a stamped and bent part in which a type of housing has been created by bending over several tabs. An exemplary structure of the clamping pocket 30th is also depicting the 4th refer to. It is a U-shaped component with a pocket base 31 , of which two bearing straps at right angles 32 , 33 go off, which run parallel to each other and form a clamping space between them. On one side opposite the bottom of the bag 31 a spring clip goes at right angles 34 from the storage tab 33 in the direction of the other bearing bracket 32 away. There are also two threaded brackets 35 and 36 provided on the front of each one bearing bracket 32 , 33 in the direction of the other bearing bracket. The threaded tabs 35 , 36 overlap at least partially and in each threaded lug 35 , 36 there is a threaded hole. These threaded holes are aligned with one another, so that there is a total of a continuous threaded hole 38 results (see 4th and 8th ).

On the back goes from a storage tab 33 a push-through protection flap 37 off which is the back of the clamping pocket 30th partially closed. Opposite this push-through protection flap 37 there is a plug-in opening on the front 16 which of the two threaded lugs 35 , 36 , the two bearing straps 32 , 33 and the bottom of the bag 31 is limited. This plug opening 16 is used to insert a conductor into the terminal pocket 30th . It is also opposite the bottom of the pocket 31 an assembly opening 15th shaped, which by the spring tab 34 , the two bearing straps 32 , 33 and the inside threaded flap 36 is limited. This assembly opening 15th serves to insert a pressure piece 50 in the clamp pocket 30th what to do when assembling the front screw terminal 10 he follows.

In the embodiment of 1 are the solder pins 12th , 13th electrically conductive at the bottom of the bag 31 appropriate. In the embodiment of 2 are the solder pins 12th , 13th electrically conductive on the push-through protective flap 37 appropriate. The same goes for the contact tulip 24 the embodiment of the 3 .

The clamp pocket 30th is in an insulating housing 20th arranged. The insulating housing has on the front 20th a ladder opening 21 on, through which a conductor through the plug opening 16 through into a conductor connection area 11 is pluggable. The insertion depth is determined by the push-through protective flap 37 limited. There is also a screw opening on the front 22nd through which a clamping screw 40 is led. The clamping screw 40 is in the threaded hole 38 in the two threaded brackets 35 , 36 screwed in and protrudes into the interior of the clamping pocket 30th . The clamping screw 40 has an actuating head for actuation 41 on, which has, for example, a slot for attaching a slotted screwdriver. The actuating head 41 is over the screw opening 22nd accessible. Furthermore, the clamping screw 40 a pressure pin at its tip 42 with preferably rounded edges, which is used to apply a pressure to a pressure piece 50 is trained.

A pressure piece 50 is also the three-dimensional view of the 5 refer to. The pressure piece 50 is an elongated, angled component with a pressure area 51 that is in a warehouse 16 pivotable between the two bearing brackets 32 , 33 is stored. To this end, the pressure piece 50 at one end two opposite bearing journals 52 , 53 on while the print area 51 at the other end of the pressure piece 50 is located.

In the area of the assembly opening 15th are on the edges of the two bearing brackets 32 , 33 Bearing recordings 80 and 81 formed into which the bearing journals 52 , 53 of the pressure piece 50 were inserted during its assembly. At the camp recordings 80 , 81 it is a matter of slots that open up to the mounting hole 15th are open. Starting from this edge of a bearing bracket, the slots in the bearing receptacles initially run in the direction of the pocket base 31 and then angle towards the back of the clamping pocket 30th away. They then run back a little in the direction of the starting edge to create a bearing indentation at the end of the respective slot 82 , 83 to form in which the bearing pin 52 , 53 of the pressure piece are held. Overall, the slots are the bearing mounts 80 , 81 therefore curved or hook-shaped.

During assembly, the pressure piece was the first 50 with its pressure area 51 advance through the assembly opening 15th led up to the bearing journals 52 , 53 the open ends of the bearing mounts 80 , 81 have reached and could be introduced into them. The bearing journals 52 , 53 were along the slots up to the bearing indentations 82 , 83 pushed. The pressure piece 50 is mounted so that it faces the clamping screw 40 is angled.

Before or after mounting the pressure piece 50 becomes a return spring 60 in the clamp pocket 30th appropriate. The return spring 60 is formed by a bent spring steel, one end of which is attached to the spring clip 34 is fixed. A freely movable end of the return spring 60 forms a pressure leg 62 that has a bending area 63 with a contact leg 61 is connected, which in turn is attached to the spring clip 34 is fixed. The depository 16 of the pressure piece 50 is from the return spring 60 recorded and is close to the contact leg 61 and the spring clip 34 . The pressure leg 62 the return spring 60 runs along the pressure piece 50 and brings about the spring force of the return spring 60 a compressive force on the pressure piece 50 which acts in the direction of the clamping screw.

Will the pressure piece 50 in front of the return spring 60 mounted, the return spring is installed 60 subsequently on the spring clip 34 fixed that her pressure leg 62 the said pressure force on the pressure piece 50 brings up. The assembly of the return spring 60 can for example from the rear through an opening between the spring tab 34 and the push-through protection flap 37 take place. Will the return spring 60 in front of the pressure piece 50 mounted, the pressure piece is 50 inserted so that it is the pressure leg 62 the return spring 60 pushes away towards the rear.

Furthermore, the pressure piece 50 for example, mounted before the clamping screw 40 into the threaded hole 38 is screwed in. Pressure piece 50 and return spring 60 are as described inside the clamping pocket 30th mounted and the clamp pocket prepared in this way 30th then from the back through an opening 24 in the insulating housing 20th inserted. Then the insertion opening 24 be closed with a lid (not shown). A cover can also be replaced by another housing part 23 be formed, as for example in the embodiment of 3 is the case in which a contact tulip 14th in such a housing part 23 is recorded. The housing part 23 points to the contacting of a conductor with the contact tulip 24 a connector opening 25th on.

After inserting the clamping pocket 30th in the insulating housing 20th can the clamping screw 40 through the screw hole 22nd through the two threaded brackets 35 , 36 be screwed in until the pressure pin 42 inside the clamping pocket 30th protrudes. With a correspondingly large screw opening 22nd can the clamping screw 40 even before the clamping pocket is introduced 30th in the insulating housing 20th be screwed in, the clamping screw 40 then from the inside into the screw opening 22nd is pushed.

Pressure piece 50 , Return spring 60 and clamping screw 40 are at the end of each other so that when they are actuated, the clamping screw 40 a compressive force on the pressure piece 50 exerts through which there is a torque around the bearing point 16 in the direction of the conductor connection area 11 learns. This takes place against the spring force of the return spring 60 going in the opposite direction from the pressure leg 62 is applied.

Should with this clamp 10 in electrical conductor 70 be connected, this is through the conductor opening 21 in the insulating housing 20th in the ladder reception area 11 inside the clamping pocket 30th pushed as the 6th can be found. 7th shows only the clamp pocket 30th with an introduced conductor 70 without surrounding insulating housing. Then the clamping screw 40 operated and protrudes further and further into the interior of the clamping pocket 30th into it. The clamping screw 40 thereby exerts a compressive force on the pressure piece 50 from whose attack and direction in 6th is shown simplified with a black arrow S. The pressure piece experiences a leverage effect 50 a torque around the bearing point 16 through which the print area 51 at the free end of the pressure piece 50 towards the ladder 70 pivots. The print area 51 is shown in simplified form, in the direction of the black arrow F against the conductor 70 pressed. This creates a clamping force that holds the conductor 70 between the bottom of the bag 31 and the pressure piece 50 pinched. An electrical contact is made with the conductor 70 with the bottom of the pocket 31 . This takes place against the spring force of the return spring 60 , their pressure leg 62 now an increased pressure force in the direction of the white arrow R on the pressure piece 50 brings up. Will the clamping screw 40 unscrewed again, the force in direction F decreases, the spring force of the pressure leg 62 lifts the pressure piece 50 again from the head 70 off and the head 70 can be pulled out.

The components described can also be used for the pressure piece 50 if the clamping screw is not fully installed 40 to hold in a defined open position in which there is the threaded hole 38 not blocked. For this purpose, a stop is provided against which the pressure piece 50 by the return spring 60 is pressed when there is no clamping screw 40 is mounted or a mounted clamping screw is not inside the clamping pocket protrudes. Such a stop is particularly easy 17th through at least one of the threaded straps 35 , 36 form. This is done using the 8th explained the one front screw terminal 10 shows without clamping screw. If the clamping screw were screwed in, its tip would move within an imaginary cylindrical screw area, which is in the 8th shown in dashed lines and with the reference number 43 is designated. Length and diameter of this screw area 43 serve only to illustrate how the stop works 17th and are not intended to provide an exact outline of the possible screwing area 43 define.

The pressure piece 50 should be caused by the compressive force of the return spring when the clamping screw is not installed or has been screwed out a long way 60 not so far in this screwing area 43 swivel so that it blocks screwing in of the clamping screw. The edges of the two threaded brackets function for this purpose 35 , 36 as a stop 17th against which the pressure piece 50 strikes. In particular, the pressure piece strikes 50 in the area of its printing area 51 at this stop 17th at.

The attack 17th can also be used to press the pressure piece 50 if the clamping screw is not installed or has been screwed out a long way, it cannot be lost in the bearing position 16 to keep. The pressure leg 62 the return spring 60 so grips the pressure piece 50 at that its bearing journals 52 , 53 in the direction of the spring tab 34 into the warehouse bookings 82 , 83 be pressed.

List of reference symbols

10.10 ', 10' '

Front screw terminal

11

Conductor connection area

12.13

Solder pin

14th

Contact tulip

15th

Assembly opening

16

Plug-in opening

17th

attack

20th

Insulating housing

21

Ladder opening

22nd

Screw opening

23

Housing part

24

Insertion opening

25th

Connector opening

30th

Clamp pocket

31

Pocket base

32.33

Bearing bracket

34

Spring tab

35.36

Threaded lug

37

Push-through protection flap

38

Threaded hole

40

Clamping screw

41

Actuator head

42

Pressure pin

43

Screwing area

50

Pressure piece

51

Pressure area

52.53

Journal

60

Return spring

61

Contact leg

62

Pressure leg

63

Bending area

70

ladder

80.81

Stock taking

82.83

Bearing indentation

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• DE 9317783 U1 [0003]
• EP 0271594 A1 [0003, 0004]
• EP 0271564 A1 [0004]
• DE 102008010162 A1 [0004]
• DE 102004021836 B4 [0004]
• DE 102004010579 B4 [0004]
• EP 3525289 A1 [0005, 0012]

Claims (16)

Front screw terminal (10) for connecting an electrical conductor (70), having a conductor connection area (11), an electrically conductive contact element, a clamping screw (40), a return spring (60) and a clamping pocket (30) on which a pressure piece (50 ) is pivotably mounted in a bearing point (16), the pressure piece (50) being pivotable in the direction of the conductor connection area (11) by actuating the clamping screw (40) against the spring force of the return spring (60) and for clamping one into the conductor connection area (11) introduced conductor (70) is formed between the pressure piece (50) and the electrically conductive contact element, and a mounting opening (15) is provided in the clamping pocket (30), through which the pressure piece (50) during assembly in the clamping pocket (30) is introduced and fed to the bearing point (16), characterized in that the clamping screw (40) lies between the conductor connection area (11) and the assembly opening (15). Front screw terminal according to Claim 1 , wherein when the clamping screw (40) is actuated, a bending area of the return spring (60) is elastically deformed and this bending area lies outside the assembly opening (15). Front screw terminal according to Claim 1 or 2 , wherein the clamping pocket (30) is formed from an electrically conductive copper material and the electrically conductive contact element is formed by the clamping pocket (30). Front screw terminal according to one of the Claims 1 until 3 , wherein the clamping pocket (30) forms two bearing straps (32; 33) each with a bearing receptacle (80; 81) and the pressure piece (50) has two opposite bearing pins (52; 53) via which the pressure piece (50) can be pivoted between the two bearing tabs (32; 33) is mounted in the bearing receptacles (80; 81), and the bearing receptacles (80; 81) are designed to be open towards the assembly opening (15). Front screw terminal according to one of the Claims 1 until 4th , wherein the tip of the clamping screw (40) lying within the clamping pocket (30) can be displaced by a screwing movement within a cylindrical screw area (43), and a stop is provided which, when the clamping screw (40) is not mounted, is activated by the return spring (60) caused movement of the pressure piece (50) in the screw area (43) limited. Front screw terminal according to Claim 5 , wherein the pressure piece (50) has a pressure area (51) which, when the clamping screw (40) is actuated, presses a conductor (70) inserted into the conductor connection area (11) against the electrically conductive contact element, and the stop controls the movement of this pressure area ( 51) of the pressure piece (50) in the screw area (43). Front screw terminal according to Claim 5 or 6th , wherein at least one wall of the clamping pocket (30) has a threaded bore into which the clamping screw (40) is screwed, and the stop (17) is formed by the wall. Front screw terminal according to one of the Claims 5 until 7th , wherein the pressure piece (50) strikes the stop transversely to the direction of movement of the clamping screw (40). Front screw terminal according to one of the Claims 1 until 9 , wherein the return spring (60) exerts a force on the pressure piece (50), which holds the pressure piece (50) in the bearing position in a captive manner when the clamping screw (60) is not installed. Front screw terminal according to one of the Claims 1 until 9 wherein the clamping pocket (30) is a stamped and bent part which has a U-shaped curved base body with a pocket base (31) from which two bearing tabs (32; 33) extend at right angles and run parallel to one another. Front screw terminal according to Claim 10 , with at least one threaded lug (35; 36) extending from the bearing lugs (32; 33) at right angles, into which the clamping screw (60) is screwed. Front screw terminal according to Claim 11 , two threaded tabs (35; 36) extending at right angles from the bearing tabs (32; 33), which at least partially overlap, and the clamping screw (60) is screwed into both threaded tabs (35; 36) in the overlapping area. Front screw terminal according to one of the Claims 10 until 12th , with a push-through protection tab (37) extending from at least one bearing tab (32; 33) at right angles, which delimits the conductor connection area (11) in the plug-in direction of the conductor (70). Front screw terminal according to one of the Claims 1 until 13th , wherein the clamping pocket (30) forms a spring tab (34) to which the return spring (60) is fixed. Front screw terminal according to Claim 14 , wherein the spring tab (34) is on the side of the mounting opening (15). Front screw terminal according to one of the Claims 1 until 15th , wherein the clamping pocket (30) in one Insulating housing (20) is arranged, which covers the assembly opening (15) of the clamping pocket (30).

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