EP2227840B1 - Connecting flange, particularly for an electric terminal - Google Patents

Description

The present invention relates to a connecting flange, in particular for an electrical connection terminal or another electrical component, which comprises a housing and a slot provided thereon for receiving a screw, wherein the shaft has a shaft wall, in particular of an elastic material and wherein a securing device is provided to take the screw captive in the shaft. Although the invention will be described below with reference to the use as a connecting flange, the invention can also be used for securing screws in the shafts to electrical components in general.

Locking arrangements for screws have become known in the prior art. For example, is from the DE 296 21 267 U1 a Schraubklemme become known, in which the screw head is covered by a cover housing except for a screwdriver opening. Distributed over the circumference are provided in the cover housing in the axial direction formed ribs which have a minimum distance from each other, which is smaller than the diameter of the screw head. When screwing the clamping screw, the ribs are deformed and abraded in this prior art. Due to the elasticity of the ribs, the screw is taken captive in the cover housing.

A disadvantage of this known solution, however, is that in the longitudinal direction of the screw on the cover housing extending ribs must be made in close coordination with the screw to be used to ensure safe operation.

The tolerances to be complied with are very tight, since the ribs on the one hand must enable screwing in the screw without destroying the cover housing by overstretching, while on the other hand, the screw must be held securely after insertion. This leads to the need to comply exactly with the dimensions and causes a high production cost and thus higher production costs.

From the DE 30 28 958 C2 is a terminal has become known in which the clamping screw is arranged retractable in a shaft of a body. In the shaft profiling is provided, which can be deformed elastically when screwing in and when sweeping the head. After sweeping the profiling, the profiling deforms only partially elastically back, so that the profiling performed as a bead serves as a backup.

Also in this known from the prior art arrangement a very close coordination of the dimensions and the compliance with very tight manufacturing tolerances is required to reliably prevent destruction of the component during insertion and loss of the screw used.

Furthermore, prior art devices have become known in which a circumferential rib is provided in the screw receiving shaft, which has a smaller free inner diameter than the largest outer diameter of the screw head. If a screw is inserted into such a shaft and guided past the annular rib, it is taken captive in the shaft. However, this solution, which in itself works well, requires precise coordination of the manufacturing tolerances, as it can otherwise lead to the tearing off of the screw in automatic screw assembly, namely, when the expansion forces in the passage of the screw head exceed the durability of the component.

Such a system works with slow assembly by hand or even with exact compliance with the tolerances, which in turn but causes a considerable manufacturing effort and thus higher costs.

From the FR 1 173 759 is an electrical screw with a screw known according to the preamble of claim 1.

From the CH 511 522 is a terminal for electrical conductors with a clamping screw known.

Prior to the cited prior art, it is therefore an object of the present invention to provide a device for captively receiving a screw on an electrical component and in particular on a terminal available, with greater manufacturing tolerances allowed and high reliability of the captive can be achieved.

This object is achieved by a connecting flange with the features of claim 1. Preferred developments of the invention are defined in the subclaims. Further advantages and features will become apparent from the description of the embodiment.

An inventive connecting flange is provided in particular for an electrical terminal or another electrical component and comprises at least one housing and at least one shaft provided therein for receiving a screw. In the connection flange according to the invention, the shaft has a shaft wall made of an elastic material. On the shaft wall a securing device is designed or provided so that the screw of the shaft is at least in a non-screwed state captive captive. For this purpose, the length of an inner circumference of the securing device is adapted to the length of the outer circumference of the screw. Furthermore, a free cross section of the securing device and the largest cross section of the screw have different shapes.

The invention offers many advantages. A considerable advantage is that due to the different cross-sectional shapes, the screw in the shaft is taken captively even in the non-bolted state.

In addition, since the length of the inner periphery of the securing device is adapted to the length of the outer circumference of the screw, this means that the screw diameter is at least one point greater than the corresponding free diameter of the shaft.
The result is a natural captive for the screw in the shaft.

According to the invention, the screw is introduced by utilizing the elastic properties of the shaft wall. Characterized in that the length of the outer circumference of the screw and the inner circumference of the securing device are adapted to each other, this means that while the insertion of the screw, a local deformation of the shaft wall must occur so that the screw is inserted, but since the circumferential lengths are adjusted, no Elongation of the entire circumference of the shaft wall done, but it is sufficient in each case local bends, but do not lead to an overall elongation of the shaft. After passing through the screw or the screw head, the shaft wall deforms elastically back, so that the screw is taken captive.

In particular, the length of the inner circumference of the securing device, that is approximately the length of the outer circumference of the screw, wherein the length of the inner periphery of the securing device is in particular slightly larger than the length of the outer circumference of the screw, so as to ensure that a total no stretching of the shaft wall over the entire extent occurs or is required. This means that the inner circumference of the securing device, for example, 1%, 3% or even about 5% or more longer than the outer circumference of the screw.

In a preferred embodiment of the invention, the cross-sectional shape of the shaft is polygonal, while the screw has a rounded cross-section.

Also possible would be a polygonal screw which has a number of corners, which is significantly higher than the number of corners of the shaft. This example is not an embodiment of the invention.

The fact that the circumferential lengths are adapted to one another causes a slight local deformation of the shaft walls by the introduction of the screw into the polygonal shaft, the shaft wall being locally bent, in particular at the corners of the shaft.

Preferably, the shaft wall on the securing device between four and eight corners, wherein the corners can also be performed rounded.

In another preferred embodiment, the cross-sectional shape of the screw is polygonal, while the shaft has a rounded or round cross-section. In this embodiment, a compression and stretching of the material is locally effected analogous to the previous embodiment, with a total of a complete extension of the shaft circumference is reliably avoided, thereby overloading the shaft during insertion of the screw is prevented.

In a particularly preferred embodiment, which is not an embodiment of the invention, the screw has an oval cross section and the shaft has a round or rounded cross section or vice versa and the screw has a round cross section and the shaft has an oval cross section. In this case, due to the adapted circumferential lengths, the smallest diameter of the oval cross section is shorter and the largest diameter of the oval cross section longer than the diameter of the round cross section, so that when introducing the screw locally material is displaced elastically, which after passing through the screw at least substantially again elastically deformed. As a result, the screw is reliably received by the securing device in the shaft.

In preferred developments of all embodiments described above, the shaft wall preferably consists at least partially of an insulating material. Preferably, the shaft wall is thin-walled in order to increase the elasticity.

In the case of more massive bodies, the shaft wall can be of thin-walled construction and can be surrounded radially at least in sections by a trench or the like which preferably extends deeper from the surface than the distance between the securing device and the surface. As a result, the elasticity of the shaft is increased, since locally the material of the shaft wall can bend radially outward. In addition, the bending of the shaft wall is facilitated radially inward, since the shaft wall there due to the trench conditionally has no contact with the surrounding material of the body.

In all embodiments, the housing consists at least partially of a plastic and in particular of a thermoplastic material which has elastic properties.

Preferably, the securing device is arranged at or in the vicinity of the accessible end of the shaft, whereby the required installation depth is limited.

In preferred embodiments, the securing device comprises at least one inwardly projecting holding device or holder. In particular, two approximately opposite and in each case inwardly projecting retaining ribs are preferably provided on the housing or on the wall of the shaft. Two opposite holding ribs provide a reliable hold.

In all embodiments, the shaft wall preferably has a phase on its outer side in the region of the securing device.

Advantageously, the shaft is at least partially made of an insulating material. As a rule, the screw is equipped with an enlarged screw head and a shaft with a threaded section.

In the depth of the shaft extends behind the securing device preferably a central portion of the shaft, in which the screw or the screw head is fully circumferentially with game accepted, so that the securing device forms an undercut, which extends over an angular portion or more angular portions or even around extending the shaft around.

Preferably, the shaft is formed round in this central portion of the shaft and there, the inner circumference of the shaft is significantly larger than the outer circumference of the screw head and the screw.

The connecting flange according to the invention allows the captive capture of screws with significantly reduced requirement for accuracy of manufacture, so that a more cost-effective production with higher quality is possible.

Further advantages and features of the present invention will become apparent from the description of the embodiment, which will be explained below with reference to the following drawings.

Fig. 1

einen Anschlussflansch gemäß der Erfindung in einer Aufsicht;

Fig. 2

den Anschlussflansch nach Fig. 1 im Querschnitt A-A mit einer schematisiert dargestellten Schraube;

Fig. 3

eine Schraube für den Anschlussflansch nach Fig. 1; und

Fig. 4

die Querschnitte des Schachtes und des Schraubenkopfes des Anschlussflansches nach Fig. 2.

Show:

Fig. 1

a connection flange according to the invention in a plan view;

Fig. 2

the connection flange Fig. 1 in cross section AA with a screw schematically illustrated;

Fig. 3

a screw for the connection flange after Fig. 1 ; and

Fig. 4

the cross sections of the shaft and the screw head of the connection flange after Fig. 2 ,

An embodiment of the present invention will now be described with reference to the accompanying drawings.

In Fig. 1 is a plan view of the connecting flange 1 according to the invention shown, which comes in particular for use on electrical terminals. For this purpose, the terminal may serve to receive one or more conductors and be provided for example at one or both ends of the housing with a connecting flange according to the invention, in order to fasten such a terminal to a further component. But it is also possible to use the invention for securing a conductor to a terminal.

The connecting flange 1 according to the invention has a housing 2, in which a shaft 3 is provided, in which the screw 4 is received, as can be seen in particular from the illustration Fig. 2 results. In Fig. 2 is the cross section AA from Fig. 1 shown.

The housing 2 and in particular the shaft wall 5 of the shaft 3 are here in the embodiment made of an elastic material and in particular consist of a thermoplastic material that can be elastically deformed.

In Fig. 2 FIG. 2 shows the screw 4 shown only schematically, which is equipped with a screw head 24 and with a threaded screw shaft 25. The screw 4 is captively received in the shaft 3 of the housing 2, so that the in Fig. 2 shown state 7 results in which the screw is taken captive and especially in the non-bolted state.

For this purpose, the shaft wall 5 a safety device 6, which is designed in the manner of an undercut and causes the free diameter of the shaft 3 at least one point is smaller than the corresponding diameter of the screw 4 at this point. Generally speaking, the largest diameter of the screw 4 has a different cross section than the smallest cross section of the shaft 3, while the circumferential lengths of the largest screw cross section and the circumferential length of the smallest shaft cross section are at least approximately matched. This has the consequence that the smallest shaft diameter is greater than the smallest screw diameter, so that the screw 4 is taken captive in the shaft 3 after sweeping the securing device 6.

As in particular from the illustration Fig. 4 can be removed, in which the largest cross-section 9 of the screw 4 and the free cross section 8 of the securing device 6 are shown, can be removed, here is the largest diameter 9 of the round here screw head 24 is larger than the smallest diameter 19 of the dashed lines shown and At the same time, the eight corners 12 of the securing device 6 are provided radially outside the largest diameter 9 of the screw head 24 so that the screw head 24 is captively received in the shaft 3 by the retaining ribs 14 of the securing device 6 the circumferential lengths of the securing device of the screw head are adapted to each other.

This means here that the length of the inner circumference 10 of the securing device 6 is adapted to the length of the outer circumference 11 of the screw 4 or here the screw head 24. Here in the embodiment, the length of the inner periphery of the securing device 6 is slightly larger than the length of the outer periphery 11th the screw head 24, so that an elongation of the entire circumference of the securing device 6 during insertion the screw 4 is reliably prevented, because in such cases, this can lead to damage to the component.

The difference of the circumferential lengths may be several percent e.g. 5% or 10% or even 15%. It is essential that the shaft wall 5 can locally deform when sweeping the screw head 24, so that in the elastic deformation substantially a bending and no overstretching of the shaft wall 5 takes place.

Here in the exemplary embodiment, the width of the connecting flange 1 is about 5.4 mm, while the free diameter 20,21 and 22 are equal and about 3.9 mm. The free diameter 19 in the region of the securing device 6 is smaller and is here 3.65 mm, while the shaft wall 5 in the region of the accessible end 13 also has a free diameter 18 of 3.9 mm. This means that, in the area of the securing device 6, the free diameter 18 is conditionally reduced by the holding ribs 14 of the securing device 6 from 3.9 to 3.65 mm. Thus, a slight insertion of the screw is made possible in the accessible end 13 of the shaft 3 until the screw abuts the securing device 6.

In Fig. 3 the screw 4 for the connection flange 1 is shown in more detail. The screw head 24 and the screw shank 25 having screw 4 has here in the embodiment a circular head designed, which has a diameter of 3.8 mm. In order to turn the screw with a tool, the screw head 24 is provided with a slot 26. In other embodiments, a Phillips or an internal or external hexagon of the like. Be provided.

While the length of the screw head here is about 1.4 mm, the screw shaft 25 has a length of 6.2 mm and is provided over the greater part of its length with an external thread 30, which here as M 2.5 thread is executed. The screw shaft 25 is passed through the lower through hole 23 of the connection flange 1.

In other embodiments, other dimensions of the connecting flange 1 and the shaft 3, and the screw 4 are possible. The dimensions can be larger and smaller.

In order to facilitate the deformation of the shaft wall 5 in the region of the securing device 6 and to facilitate the production of the connecting flange 1 according to the invention, a phase 16 is provided in the region of the securing device 6 on the outside of the shaft wall 5, which increases the elasticity of the shaft wall.

Although the screw head here in the embodiment designed around and the shaft wall 5 has a polygonal cross-section, it would also be possible to make the screw 4 out of round and the shaft 3 around. This example is not an embodiment of the invention.

In all embodiments, at least in the region of the shaft bottom 33 of the free diameter of the shaft 5 is larger everywhere than the outer diameter of the screw 4 to allow easy and undisturbed rotation of the screw 4 in the shaft 3.

LIST OF REFERENCE NUMBERS

1

flange

2

casing

3

shaft

4

screw

5

shaft wall

6

safety device

7

not bolted condition

8th

free cross section of the securing device

9

largest cross section of the screw

10

inner circumference

11

outer periphery

12

corner

13

accessible end

14

holding rib

15

outside

16

phase

17

width

18

diameter

19

smallest diameter

20

diameter

21

diameter

22

diameter

23

Through Hole

24

screw head

25

screw shaft

26

slot

27

Head diameter

28

head length

29

shaft length

30

Thread diameter

31

distance

32

largest screw diameter

33

shaft bottom

Claims (11)

1. A connection flange (1), in particular for an electrical connection terminal, comprising a housing (2), a screw (4) and at least one shaft (3), provided on the housing (2), for receiving the screw (4), wherein
   the shaft (3) has a shaft wall (5) made of a resilient material, on which a securing device (6) is formed, with the result that the screw (4) can be received captively by the shaft (3) in the unscrewed state (7),
   a free cross section (8) of the securing device (6) and the largest cross section (9) of the screw (4) have different shapes,
   the length of an inner periphery (10) of the securing device is adapted to the length of the outer periphery (11) of the screw (4), characterised in that
   a free diameter of the shaft (3), at least at one point, is smaller than the corresponding diameter of the screw (4) at this point due to the securing device (6), and
   the cross-sectional shape (8) of the shaft is polygonal, whereas the screw (4) has a rounded cross section (9).
2. The connection flange according to Claim 1, wherein the shaft wall (5) on the securing device (6) has between four and eight corners (12).
3. The connection flange (1) according to one of the preceding claims, wherein the shaft wall (5) consists substantially partially of an insulating material.
4. The connection flange (1) according to one of the preceding claims, wherein the shaft wall (5) is formed at least in portions in a thin-walled manner.
5. The connection flange (1) according to one of the preceding claims, wherein the shaft wall (5) is radially outwardly surrounded at least in portions by a channel.
6. The connection flange (1) according to one of the preceding claims, wherein the housing (2) consists at least partially of a plastic, in particular of a thermoplastic.
7. The connection flange (1) according to one of the preceding claims, wherein the securing device (6) is arranged on the accessible end (13) of the shaft (5).
8. The connection flange (1) according to one of the preceding claims, wherein the securing device (6) comprises at least one inwardly protruding holding rib (14).
9. The connection flange (1) according to the preceding claim, wherein the housing comprises two approximately mutually opposed holding ribs (14) each protruding inwardly.
10. The connection flange (1) according to one of the preceding claims, wherein the securing device (6) is formed as an inwardly protruding, peripheral holding rib (14).
11. The connection flange (1) according to one of the preceding claims, wherein the shaft (5), on its outer face (15), has a phase (16) in the region of the securing device (6).

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