WO2000021160A1

WO2000021160A1 - Spring clamp

Info

Publication number: WO2000021160A1
Application number: PCT/EP1999/007184
Authority: WO
Inventors: Jürgen Pries; Dietmar Hillebrand
Original assignee: Aeg Niederspannungstechnik Gmbh & Co. Kg
Priority date: 1998-10-02
Filing date: 1999-09-28
Publication date: 2000-04-13
Also published as: AU753112B2; CN1286817A; PL195886B1; HUP0004707A3; NO20002808L; NO318047B1; PL340759A1; BR9907294A; AU6329899A; HU224145B1; CN1135659C; NO20002808D0; EG21982A; HUP0004707A2; DE19845475B4; TR200001540T1; EP1038334A1; DE19845475A1

Abstract

The invention aims at improving a spring clamp that can be moved to an open position for clamping a conductor in such a way that clamping of said conductor can be performed as easily as possible. To this end, a clamping body (2) of the spring clamp can be held in open position without any actuation using a tool or the like. The conductor can be very easily inserted into the spring clamp when the clamping body (2) is automatically placed in open position due to the fact that no additional activity is required aside from inserting the conductor. Once the conductor has been successfully inserted, the assembler can concentrate on clamping of the conductor by releasing from its current state the clamping body (2) held without any actuation.

Description

SPRING CLAMP

description

The invention relates to a spring-loaded terminal according to the preamble of claim 1.

A conventional generic spring clamp is known from DE 93 12 380 Ul. It consists of an insulating body in which at least one clamping body receptacle is provided. The clamping body receptacle receives a clamping body, for example a cage tension spring. The clamping body can be brought into an open position by an opening device, in which a conductor to be clamped can be inserted into the clamping body in order, for example, to establish a power connection. For insulation and safety reasons, a lever which is accommodated in the insulating body and hinged to it is used as the opening device. By depressing the lever using a screwdriver or similar tool, the lever is pivoted about its pivot axis and presses against a loop-like part of a clamping leg of the cage tension spring. As a result, the loop-like part of the clamping leg is elastically deformed, whereby the cage-like recess in the clamping leg is released. The clamping body is biased in the closing direction, so that the clamping body clamps the conductor which has now been introduced when the lever depressed by the screwdriver is released.

Spring clips of the type mentioned are generally used as terminal blocks. The insulating body is a housing that is only continuous on one side and open on the opposite side. The clamp body and a busbar extending from there is inserted into this open housing.

There are usually two or more clamping bodies in a spring-cage terminal block, which are connected by a common busbar. The last-mentioned spring-loaded terminals form coupling links the whose insulating body can be snapped onto a top-hat rail permanently installed on a wall. By lining up several insulating bodies side by side, a multi-pole terminal block is created. Terminal blocks can optionally also be made from a one-piece housing.

It has proven to be disadvantageous that a tool must be used to clamp a conductor in the conventional spring-loaded terminal. A mechanic has to press the screwdriver against the lever to open the clamp body with one hand, while he introduces the conductor into the open clamp body with his other hand. The lever must be kept actively printed while the conductor is actively inserted into the clamp body. Carrying out these two active activities to clamp the conductor simultaneously proves to be effortless.

From DE 39 10 937 AI, a spring-loaded terminal shown in FIG. 3 is known, in which a lever 13 articulated on an insulating body 15 and projecting outwards is used to open the clamping body 14. The connection of conductors 16 is thus simplified because the lever 13 projecting outwards is more easily accessible to the fitter. But even with this spring-loaded clamp, an active actuation by a tool is necessary to open the clamp body 14, with which the lever 13 must be pressed down, around the conductor 16 m a cage opening 14b in a loop-like part of a clamp leg 14a of the clamp body realized as a Kaflgzugfeder 14 to introduce. In addition, the same two active activities as already described above must be carried out simultaneously for clamping.

The invention has for its object to develop a spring clamp according to the preamble of claim 1 so that jamming the conductor is as simple as possible. This object is achieved according to the invention by the features of claim 1.

Advantageous further developments are defined in the subclaims.

According to the invention, the clamp body is stable in its open position without the need for actuation by a tool or the like. When the clamping body is held automatically in the open position, it is very easy to insert a conductor m the spring-loaded terminal, since in addition to the introduction of the conductor, no further active activity has to be carried out simultaneously. After the conductor has been inserted, the fitter can concentrate on jamming the conductor by releasing the clamp body, which is kept free of actuation, from its state. During the jamming by jerking the clamping body m the closed position under its prestress acting in the closing direction, no further active activity has to be carried out at the same time. The installer only has to make sure that the conductor does not accidentally slip out of the clamp body. To do this, it secures the conductor passively while it returns the clamp body to its closed position, in which the conductor that has now been inserted is clamped.

According to an advantageous development, the clamping body can be locked in its open position by means of the opening device. This latching of the opened clamping body with the opening device ensures a reliable open position of the clamping body and largely prevents accidental jamming at an undesired point in time. On the other hand, the fitter can simply deliberately overcome the latching of the opening device with the clamping body in order to bring about the clamping of the conductor.

The formation of the opening device as a lever articulated on the insulating body and pressing on the clamping body makes the conductor easier to clamp, since the articulated lever is captively connected to the spring-loaded terminal and is therefore reliably available at every place of use.

The use of a Kaflgzugfeder as clamping body is particularly advantageous. The Kaflgzugfeder has a loop-like clamping leg with a cage opening formed therein, into which the conductor is inserted. The lever can press one of its free ends onto the clamping leg of the cage tension spring, so that the cage opening is released. This results in actuation which is particularly smooth and less prone to disruption when the lever is articulated in the middle and makes cam-like contact at its one free end with the clamping leg, while its other free end is angled. When the lever is pivoted, the contacting free end slides along the stationary clamping leg, so that a jerky or sudden squeezing of the conductor in the cage opening when the cage spring is closed is prevented. The Kaflgzugfeder is also opened gradually so that the Kaflgzugfeder is prevented from tilting.

A flat latching between the lever and the clamping leg can be achieved particularly advantageously in that the end face of the free end of the lever pointing towards the clamping leg is of concave design and is therefore adapted to the external shape of the loop-like part of the clamping leg. The shape of the concave face of the free end of the lever is exactly matched to the outer shape of the clamping leg at the point where the free end of the lever is in contact with the cage spring in the open position. The concave, flat latching ensures particularly reliable maintenance of the open position of the spring-loaded terminal. There is practically no possibility that the spring clamp may snap shut.

The articulation point of the lever is selected so that the closing force of the Kaflgzugfeder via its clamping leg on the lever in such a way is initiated that the lever held in the open position remains stable in this position. In this case, the biasing force of the open cage tension spring pointing in the closing direction acts to hold the lever in the open position.

The assembly on site is particularly simplified for the fitter in that the spring-loaded terminal is supplied prepared with the clamp body held in the open position. Before a conductor is clamped, the spring-loaded terminal does not have to be opened first, so that the fitter can start directly with the activity of inserting the conductor without further preparatory measures.

The invention is explained in more detail below on the basis of a preferred exemplary embodiment with reference to the attached drawings.

Show it:

1 is a side view of an embodiment of the spring-loaded terminal according to the invention in the open position,

Fig. 2 is a side view of the embodiment of FIG. 1 in the closed position and

Fig. 3 shows a spring clip according to the prior art.

Figs. 1 and 2 show a preferred exemplary embodiment ei ^¬ ner spring terminal.

An insulating body 1 of the spring-loaded terminal is preferably formed from resin or plastic as a housing that is continuous on one side. The outer shape of the insulating body is adapted to the special field of application of the spring-loaded terminal and will not be explained in more detail. A busbar 5 is molded or inserted into the insulating body 1. The busbar 5 serves in the shown Exemplary embodiment for deriving or supplying current from or to a cage clamp spring 2 in contact therewith. The busbar can also connect two or more cage clamp springs to one another. A guide device 5a is formed in one piece with the busbar 5 at the contact point with the cage tension spring 2. The guide device 5a prevents a lateral protrusion of the spliced-on wires of a conductor (not shown) to be clamped by the cage spring 2.

The cage tension spring 2 has a loop-like design

Clamp leg 2a on. The cage spring 2 is inserted into the insulating body 1 so that it is held in contact with the busbar 5 at the contact point m near the guide device 5a. The clamping leg 2a is provided near one of its free ends with a cage opening 2b through which the opposite end of the cage tension spring 2 and the busbar 5 are guided. In the position shown in FIG. 1, the cage tension spring 2 is in the open position, in which the conductor can be inserted through the cage opening 2b on the side of the busbar 5. The clamping leg 2a of the cage tension spring

2 is the open position by a lever explained later

3 loaded and held, wherein it is biased in the closing direction. In the maximum open position, the cage opening 2b rests on its side opposite the busbar 5 at the other free end of the cage tension spring 2.

Fig. 2 shows the relieved state of the spring clamp, in which the cage spring 2 is relaxed to a residual tension and assumes its closed position. In this state, the side of the cage opening 2b adjacent to the busbar 5 bears against the busbar 5.

As shown in FIGS. 1 and 2, the lever 3 is articulated at a pivot point 3d on the insulating body 1. The lever 3 preferably consists of an insulating material, such as resin or

Plastic. The articulation point 3d is roughly in Langser- Extension of the lever 3 in the middle of the lever 3. By actuating the lever 3, the cage spring 2 is deformable for opening and closing. For this purpose, the lever 3 is in cam-like contact at one of its free ends with the loop-like part of the clamping leg 2a of the cage tension spring 2. At its other end 3b, the lever is designed to be slightly angled for actuation.

An end face of the free end 3a of the lever 3 which is in contact with the clamping leg 2a is concave. The

The end face can be locked flat with the loop-like part of the clamping leg 2a in the open position of the cage tension spring 2. With regard to this end face, the articulation point 3d of the lever 3 on the insulating body 1 is selected such that a closing force applied to the lever 3 by the clamping leg 2a biased in the closing direction keeps the lever 3 in the open position stable in this position. The contour of the contact-side end of the lever 3 on the side facing the cage spring 2 in the closed position is rounded at the transition from the concave end face to the longitudinal extension of the lever 3, so that pivoting of the lever 3 results in the cam-like contact in which the contact-side end of the lever 3 slides on the clamping leg 2a of the cage tension spring 2 and deforms it.

The angled end 3b of the lever is provided with a passage 3c into which a tool 4, for example a screwdriver, can be inserted for actuation. The angle of the lever 3 on the actuation side is selected such that the angled end 3b projects beyond the contour of the insulating body 1 in the closed position. The passage 3c with the angled end is also in the closed position outside the contour of the insulating body 1.

The insulating body 1 has integral stop sections la, lb and lc for each of the end positions of the lever 3. The stop section la for the closed position of the lever 3 comes into contact with the actuation-side part of the lever 3. For the open position, two stop sections 1b and 1c are provided, one of which comes into contact with the part of the lever 3 on the contact side near the articulation point 3d and the other further away.

It is of particular importance that the spring-loaded terminal is supplied ready for assembly with the cage spring 2 held in the open position.

The conductor is clamped with the exemplary embodiment of the spring-loaded terminal as follows.

The fitter inserts the conductor through the cage opening 2a along the conductor rail 5 into the cage tension spring 2, which is held in the open position without actuation. In this state, the fitter only has to make sure that the inserted conductor does not accidentally slip out of the open spring-loaded terminal. Then the fitter actuates the open position m t of the cage spring 2 latched lever with the screwdriver 4 inserted into the passage 3c, whereby the latching is released and the cage spring 2 clamps the conductor inserted through the cage opening 2a against the conductor rail 5 due to its pretension. The lever 3 is moved into its closed position, which protrudes beyond the contour of the insulating body 1, so that the fitter can recognize whether the conductor has been jammed.

Although a cage tension spring is used as the clamping body in the exemplary embodiment shown, any type of clamping body can be used instead. The sprag must be able to be brought into the open position by an opening device.

In the embodiment shown, the lever serves as an opening device for the clamping body. It holds the clamping body in the open position without actuation by locking it with it. Instead of the lever articulated on the insulating body, it can also be used a pin not hinged to the insulating body can be used, with which the clamping body can be opened and held in the open position without actuation. This pin can, for example, be a one-way pin that is only attached to the spring-cage terminal supplied and is intended to be thrown away after the first jamming. When using multiple spring clips in the form of a terminal block, a plurality of pins can be connected to form a pin unit. By removing this pin unit, all or a selection of the conductors inserted into the terminal block can be jammed at once.

Claims

claims

1. Spring-cage clamp consisting of an insulating body (1) with at least one clamping body receptacle for receiving a clamping body (2), which can be bung by an opening device (3) into a biased open position in the closing direction, m a conductor to be clamped can be inserted, characterized in that that the clamping body (2) can be kept in the open position without actuation

2. Spring clamp according to claim 1, characterized in that the clamping body (2) by the opening device (3) can be locked in the open position.

3. Spring-loaded terminal according to one of claims 1 or 2, characterized in that the opening device (3) is a lever articulated on the insulating body (1), by the actuation of which the clamping body (2) is deformable for opening and closing.

4th Spring clamp according to claim 3, characterized in that the clamping body (2) is a cage tension spring.

5. Spring-loaded terminal according to claim 4, characterized in that the lever (3) is articulated in its longitudinal extent approximately centrally on the insulating body (1), at one (3a) of its free ends with a loop-like part of a clamping leg (2a) of the cage tension spring ( 2) is in cam-like contact and is configured at its other end (3b) to be slightly angled for actuation.

6. Spring clamp according to claim 5, characterized in that the end face of the free end (3a) in contact with the clamping leg (2a) of the lever (3) is concave, which with the loop-like part of the clamping leg (2a) in the open position the cage tension spring (2) can be locked flat.

7. Spring clamp according to claim 5 or 6, characterized in that the angled end (3b) of the lever is provided with a passage (3c) into which a tool (4) can be inserted for actuation.

8. Spring clamp according to one of claims 5 to 7, characterized in that the angled end of the lever protrudes in the closed position over the contour of the insulating body.

9. Spring-loaded terminal according to one of claims 5 to 8, characterized in that the articulation point (3d) of the lever (3) on the insulating body (1) is selected so that a by the biased in the closing direction clamping leg (2a) on the lever (3 ) applied clamping force holds the lever (3) in the open position stable in this position.

10. Spring clamp according to one of claims 1 to 9, characterized in that the spring clamp is prepared for assembly with the clamping body (2) held in the open position.