DE102016121476B4 - Cable strain relief and connectors with such cable strain relief - Google Patents

Abstract

Cable strain relief (1) for the centered relief of a cable (2) from a tensile force, with a first and a second cable clamp element (10, 11) and a tensile force forwarding element (20), the cable strain relief (1) being in a motorized state of the cable strain relief (1). is mounted on the cable (2), the first and second cable clamp elements (10, 11) being arranged on the cable (2) in the assembled state, so that the cable (2) is immovable relative to the first and second cable clamp elements (10 , 11) is clamped between the first and second cable clamp elements (10, 11) and wherein the first and / or the second cable clamp element (10, 11) optionally each form or form at least one tensile force dissipation surface (12), which is at least in the mounted State of the cable strain relief (1) is arranged on a tensile force receiving surface (21) of the tensile force forwarding element (20), characterized in that the tensile force forwarding element (20) is formed by a spring element (22) and an end sleeve (30) and the spring element (22) between the at least one tensile force dissipation surface (12) and the end sleeve (30) are arranged and the spring element (22) forms the tensile force receiving surface (21) on the cable clamp element side and, in the assembled state of the cable strain relief (1), rests against the end sleeve (30) with the side facing away from the cable clamp.

Description

The invention relates to a cable strain relief for cable centering and relieving the cable of tensile forces along the cable axis, which is suitable for use with higher tensile forces. Cable strain relief devices are devices that are used to prevent strain on the connection between a conductor of the cable and a contact point by redirecting any tensile forces that act on the cable via the device to structures that are more stable than the connection.

The purpose of a cable strain relief is to prevent the connection between the conductor and the contact point from suffering mechanical damage when the cable is subjected to tensile stress, such as when the cable is pulled or accidentally tripped over the cable. Without strain relief, this would not be loaded as intended and could be damaged or completely interrupted. Cable strain relief devices that are suitable for use with higher tensile forces prevent the cable from slipping and strain on the connection between the conductor and the contact point or on the conductor, even under high tensile forces.

A wide variety of embodiments are already known from the prior art, but these usually do not allow the cable to be centered through a feedthrough, load the cable asymmetrically, often take up a large amount of space, can only be installed with a corresponding amount of space and, in many cases, require additional assembly effort.

From the DE 73 23 418 U a generic cable strain relief according to the preamble of claim 1 is known as well as a connector that has such a cable strain relief.

From the documents DE 69 12 731 U and DE 16 65 113 A Other solutions for strain relief on a cable are known.

The invention is therefore based on the object of overcoming the aforementioned disadvantages and of providing a cable-centering, space-saving and inexpensive solution which makes assembly easier and faster compared to conventional solutions.

This task is solved by a cable strain relief according to claim 1 and a connector according to claim 7.

According to the invention, a cable strain relief for centered relief of a cable from a tensile force with the features of claim 1 is proposed. For this purpose, the cable strain relief includes a first and a second cable clamp element as well as a tensile force transfer element.

The first and second cable clamp elements are arranged on the cable, so that the cable is clamped between the first and second cable clamp elements in a non-displaceable manner relative to the first and second cable clamp elements. The first and/or the second cable clamp element forms at least one tensile force dissipation surface. The at least one tensile force dissipation surface is designed to dissipate the tensile force, which is transmitted from the cable to the first and second cable clamp elements in the event of a tensile force load, via the tensile force dissipation surface. The tensile force dissipation surface is arranged on a tensile force receiving surface of the tensile force forwarding element, at least in a mounted state of the cable strain relief. In the case of a tensile force load, the tensile force receiving surface absorbs the tensile force that is derived from the tensile force dissipation surface.

An advantageous embodiment of the invention is when the first and second cable clamp elements each have a first section with a screw head support surface and a through opening, a second section with a shape that at least partially follows a cable cross section of the cable and a third section with a through hole with an internal thread. The third section also forms the tensile force dissipation surface. Because the first and second cable clamp elements are identical, the number of component variants to be provided decreases and simplifies assembly and production. In the assembled state, the first section of the first cable clamp element is arranged on the third section of the second cable clamp element and vice versa. In each case a cable clamp screw, which engages through the through opening of the first or second cable clamp element into the internal thread of the second or first cable clamp element, establishes the clamping of the cable between the first and second cable clamp elements. The respective screw head rests on the screw head support surface. The first and second cable clamp elements do not touch each other at their first and third sections. The respective second section of the first and second cable clamp elements rests on the cable at least in part following the shape of the cable cross section.

A further development is also advantageous in which the second section of the first and second cable clamp elements each forms at least one elevation in the direction of the cable. This elevation in the direction of the cable is at for example, introduced into the cable clamp element by an impression from the side facing away from the cable.

The elevation digs into the cable during installation. The elevation increases the clamping surface of the second section for clamping the cable. By burying the elevation in the cable, part of the tensile force is absorbed by the surfaces of the elevations in the direction of the tensile force.

In the exemplary embodiment according to the invention, the tensile force transfer element is formed by a spring element and an end sleeve. The spring element is arranged between the at least one tensile force dissipation surface and the end sleeve. Furthermore, the spring element forms the at least one tensile force receiving surface on the cable clamp element side. At least in the assembled state of the cable strain relief, the spring element rests on the end sleeve with the side facing away from the cable clamp. The spring element is ring-shaped, with the cable running through the through opening formed by the ring shape. The spring element extends over at least two levels, with the spring element being arranged on the end sleeve in the first level and spring arms extending to the second level with which it rests on the tensile force dissipation surfaces or at least one tensile force dissipation surface in the second level.

A further advantageous embodiment is one in which the spring element forms a centrally arranged recess through which the cable runs, at least in the assembled state, and wherein the spring element is compressed along the cable axis in the direction of a cable axis, at least in the assembled state and/or in the event of a tensile load. During assembly, the first and second cable clamps must be mounted in such a way that, in the event of a load, the spring element can be compressed in such a way that, if the first and second planes are compressed into a common plane, there is no load on the connection between the conductor and the contact element.

It is also advantageous if, in one embodiment, the end sleeve forms a circumferential wall which, at least in the assembled state, surrounds the first and second cable clamp elements in the cable circumferential direction.

In the event of a load, the first and second cable clamp elements are surrounded and protected by the wall. In the unloaded case, the cable with the first and second cable clamp elements can be moved relative to the wall. The wall serves as protection against the loosening of the clamping of the first and second cable clamp elements on the cable and to protect against environmental influences.

It is further advantageous if, in one embodiment, the end sleeve forms a cavity with an internal thread on its side facing away from the cable clamp element for receiving a sealing clamp cage, in which, at least in the assembled state, the seal clamping cage presses a seal against the cable in order to keep the side of the end sleeve facing the cable clamp element opposite the side facing away from the cable clamp element the end sleeve and to center the cable relative to the tensile force receiving surface. Because the tensile force dissipation surfaces rest on the tensile force receiving surface, the cable is not pushed in a specific direction. The centering carried out by the clamping cage is maintained in the area of the cable clamp elements. As a result, the cable lies against the seal over the entire length of the seal and is sealed over the entire length of the seal.

According to the invention, a connector with a strain relief, as described, is further proposed. The connector includes a sleeve with an external thread, onto which the end sleeve with an internal thread is screwed along the wall in a mounted state of the connector. The sleeve surrounds the contact point to which a conductor of the cable can be connected or is connected.

1. a) Aufschieben des Dichtungsklemmkäfigs mit der Dichtung auf das Kabel.
2. b) Aufschieben der Endhülse auf das Kabel.
3. c) Aufschieben des Federelements auf das Kabel.
4. d) Einschrauben einer ersten Kabelschellenschraube durch die Durchgangsöffnung der ersten oder zweiten Kabelschelle in das Innengewinde der jeweils anderen Kabelschelle, wobei die Kabelschellen so orientiert sind, dass die jeweils zweiten Abschnitte einen geeigneten Raum zum Durchführen oder Einlegen des Kabels bilden.
5. e) Einschrauben einer zweiten Kabelschellenschraube durch die verbleibende Durchgangsöffnung in das verbleibende Innengewinde, und Aufschieben der Kabelschellenelemente auf das Kabel.
6. f) Festschrauben der ersten und zweiten Kabelschellenschraube in einem vorgegebenen Abstand zu einem Ende des Kabels mit einer vorgegebenen Kraft zum Herstellen einer Kabelklemmung.
7. g) Schieben der Endhülse mit der Wandung über die Kabelschellenelemente und Aufschrauben der Endhülse mit dem Innengewinde auf das Außengewinde der Hülse, sodass in Umfangsrichtung des Kabels eine Abdichtung der kabelzugewandten Seite der Wandung hergestellt ist und die Zugkraftableitungsfläche die Zugkraftaufnahmefläche berührt.
8. h) Einschrauben des Dichtungsklemmkäfigs mit der Dichtung in die Kavität um eine Zentrierung des Kabels herzustellen und einen Innenraum des Steckverbinders abzudichten.

According to the invention, a method for assembling a plug connector is further proposed, the assembly comprising at least the following steps:

1. a) Slide the seal clamping cage with the seal onto the cable.
2. b) Push the end sleeve onto the cable.
3. c) Pushing the spring element onto the cable.
4. d) screwing a first cable clamp screw through the through opening of the first or second cable clamp into the internal thread of the other cable clamp, the cable clamps being oriented in such a way that the respective second sections form a suitable space for passing through or inserting the cable.
5. e) Screwing in a second cable clamp screw through the remaining through opening into the remaining internal thread and pushing the cable clamp elements onto the cable.
6. f) Tightening the first and second cable clamp screws in a specified manner Distance to one end of the cable with a given force to create a cable clamp.
7. g) Pushing the end sleeve with the wall over the cable clamp elements and screwing the end sleeve with the internal thread onto the external thread of the sleeve so that a seal is created on the side of the wall facing the cable in the circumferential direction of the cable and the tensile force dissipation surface touches the tensile force receiving surface.
8. h) Screwing the sealing clamp cage with the seal into the cavity to center the cable and seal the interior of the connector.

The features disclosed above can be combined in any way as long as this is technically sensible and they do not contradict each other.

• 1 eine schematische Darstellung einer Kabelzugentlastung mit geschnittener Endhülse;
• 2 eine schematische isometrische Darstellung einer Kabelzugentlastung ohne Endhülse;
• 3 eine schematische Darstellung einer Kabelzugentlastung mit geschnittener Endhülse und Federelement;
• 4 eine schematische isometrische Darstellung einer Kabelzugentlastung mit Federelement ohne Endhülse;
• 5 eine schematische isometrische Darstellung einer Kabelzugentlastung;
• 6 eine schematische isometrische Darstellung einer alternativen Ausführungsform einer Kabelzugentlastung.

Other advantageous developments of the invention are characterized in the subclaims or are shown in more detail below together with the description of the preferred embodiment of the invention with reference to the figures. Show it:

• 1 a schematic representation of a cable strain relief with a cut end sleeve;
• 2 a schematic isometric representation of a cable strain relief without an end sleeve;
• 3 a schematic representation of a cable strain relief with a cut end sleeve and spring element;
• 4 a schematic isometric representation of a cable strain relief with a spring element without an end sleeve;
• 5 a schematic isometric representation of a cable strain relief;
• 6 a schematic isometric representation of an alternative embodiment of a cable strain relief.

The figures are only schematic examples. The same reference numbers in the figures indicate the same functional and/or structural features. Insofar as the figures show an integral design of the tensile force transfer element 20, which is integrally formed by the end sleeve, it is not an embodiment according to the invention, but rather a fact to explain the invention.

1 shows a cable strain relief 1 in which the cable 2 is relieved of a tensile load in the longitudinal direction of the cable. In part, the tensile force is transmitted from the cable to the end sleeve 30 by clamping a seal through the seal clamping cage 33. The majority of the tensile force is absorbed by the clamping of the cable clamp elements 10 and 11, which clamp the cable 2 between them, and from the cable clamp elements 10 and 11 via the tensile force dissipation surfaces 12 to the tensile force receiving surfaces 21 and the tensile force forwarding element 20, which is integrally connected to the end sleeve 30 is trained, derived. Through the elevation 17, which is impressed from the outside into the second section 15 of the first and second cable clamp elements 10 and 11 and which are each buried in the cable 2, the tensile force is additionally transferred to the cable clamp elements 10 and 11 and slipping or shifting is prevented of the cable 2 relative to the cable clamp elements 10, 11 is prevented. The cable clamp elements 10 and 11 are clamped using two cable clamp screws 18. A cable clamp screw 18 runs through a through opening in the first section 13 of the first or second cable clamp element 10, 11 and engages in the internal thread of the through hole in the third section 16 of the second or first cable clamp element 10, 11.

The cable clamp screws 18 each rest with their respective screw heads on the screw head support surface 14 of the first section 13 of the respective cable clamp element 10, 11. The first section 13 of the first or second cable clamp element 10, 11 does not rest on the third section 16 of the second or first cable clamp element 10, 11. A distance is formed between the first section 13 of the first or second cable clamp element 10, 11 and the third section 16 of the second or first cable clamp element 11, 10. The cable clamp elements 10, 11 are punched and bent from sheet metal, cast from plastic or made from a solid metal material by machining and are each designed to accommodate the flow of force in order to be able to absorb and dissipate the high tensile forces that act along the cable.

The tensile force transfer element 20 or the end sleeve 30 and the wall 31 are made of metallic material or plastic and designed to accommodate the flow of force in order to transfer the force to a housing on which the end sleeve 30 is mounted or to a sleeve. A metallic design of the cable clamp elements 10, 11 and/or the tensile force forwarding element 20 results in extensive independence from temperature influences and makes the cable clamp elements 10, 11 and the tensile force forwarding element 20 temperature-resistant. The sleeve, as part of a plug connection, conducts the force in turn is transferred to a suitable force dissipation device.

The first and second cable clamp elements 10, 11 are mounted at a distance from the cable end or conductor end, so that no tensile load is passed on to the conductor ends or the cable end. By screwing the seal clamping cage 33 into the cavity 32, a seal against environmental influences such as moisture is also created by compressing the seal and pressing it against the cable. Due to the arrangement of the cable clamp elements 10, 11 and the tensile force forwarding element 20, the cable strain relief can be implemented in a small installation space. Due to the arrangement of the cable clamp elements 10, 11 surrounded by the wall 31, the risk of injury to the end user is low.

2 shows the cable 2 with the first and second cable clamp elements 10, 11 in an isometric detailed view. The cable clamp screws 18 clamp the cable clamp elements 10, 11 against the cable 2 and dig the elevation 17 into the cable when the cable clamp screws 18 are screwed in. The first section 13 of the cable clamp elements 10, 11 with the screw head support surface 14 is tapered, so that the first section 13 can penetrate into the space of the tensile force dissipation surfaces 12, which are formed symmetrically in the longitudinal direction of the cable by the third section 16. The second section 15 of the cable clamp elements 10, 11 at least partially follows the round cable cross section and forms a partial circle in the contour.

3 shows a cable strain relief 1 as in 1 , wherein the tensile force transfer element 20 is formed from a spring element 22 and the end sleeve 30.

4 shows the cable 2 with the first and second cable clamp elements 10, 11 and the sealing clamp cage 33 in an isometric detail view 2 , wherein the spring element 22 is shown as part of the tensile force forwarding element 20.

The spring element 22 has a substantially circular shape, with the cable 2 passing through the resulting opening. The spring element 22 runs over at least two planes, with a part of the spring element 22 lying in the first plane and forming a resilient arcuate section between two sections lying in the first plane. Spring arms extend from the sections in the first level into the second level. In the assembled state, the spring element 22 rests with the first level on the end sleeve 30 and with the tensile force receiving surfaces 21, which are formed by the spring arms in the second level, on the tensile force dissipation surfaces 12 of the cable clamp elements 10, 11. The spring element 22 is, for example, made of metallic material and insensitive to temperature.

5 shows the cable strain relief 1 in an isometric view as in 4 . In addition, the end sleeve 30 and the wall 31 formed by the end sleeve 30 can be seen. By moving the end sleeve 30 along the longitudinal axis of the cable in the direction of the cable clamp elements 10, 11, the wall 31 can be brought over the cable clamp elements 10, 11. The wall 31 can be screwed into a suitable mating thread in a sleeve or a housing via an internal or external thread formed by the wall 31. Tensile forces can be dissipated onto the sleeve or the housing via the cable clamp elements 10, 11, the tensile force dissipation surfaces 12, the tensile force receiving surfaces 21, the tensile force forwarding element 20 and the wall 31.

6 shows a cable strain relief 1 in an isometric view similar to the view of 2 . As with the 1 described, the cable clamp elements 10, 11 can be punched and bent from sheet metal or alternatively made of plastic or cast from plastic or made from a solid metal material by machining and each designed to accommodate the flow of force in order to absorb and dissipate the high tensile forces that act along the cable can. This design according to 6 corresponds to a solution in which the cable clamp elements 10, 11 are made of plastic. For this purpose, the upper and lower cable clamp elements 10, 11 have a semi-cylindrical jacket-shaped shape, with the two cable clamp elements 10, 11 being clamped on the cable jacket of the cable 2 by means of a screw connection with cable clamp screws 18. On the cable clamp elements there is a projection 19b at one end and a corresponding recess 19a at the opposite end, which are designed in such a way that the projection 19a of one cable clamp element 10, 11 extends into the respective recess 19a of the oppositely arranged cable clamp element 10, 11 engages with positive locking.

The recess 19a is delimited in the axial direction by a front and rear wall 19d, against which a front wall 19c and a rear wall 19d of the engaging projection 19a engage.

The implementation of the invention is not limited to the preferred exemplary embodiments given above. Rather is A number of variants are conceivable, which make use of the solution presented even in fundamentally different designs. For example, the first and second cable clamp elements in the area of the second section can be designed with a shape that only partially follows the shape of the cable cross section.

Reference symbol list

1

Cable strain relief

2

Cable

10

first cable clamp element

11

second cable clamp element

12

Tensile force dissipation surface

13

first section

14

Screw head support surface

15

second part

16

third section

17

survey

18

Cable clamp screw

19a

recess

19b

head Start

19c

front wall

19d

rear wall

20

Traction force transfer element

21

Tensile force receiving surface

22

Spring element

30

End sleeve

31

wall

32

cavity

33

Seal clamp cage

Claims (7)

Cable strain relief (1) for the centered relief of a cable (2) from a tensile force, with a first and a second cable clamp element (10, 11) and a tensile force forwarding element (20), the cable strain relief (1) being in a motorized state of the cable strain relief (1). is mounted on the cable (2), the first and second cable clamp elements (10, 11) being arranged on the cable (2) in the assembled state, so that the cable (2) is immovable relative to the first and second cable clamp elements (10 , 11) is clamped between the first and second cable clamp elements (10, 11) and wherein the first and / or the second cable clamp element (10, 11) optionally each form or form at least one tensile force dissipation surface (12), which is at least in the mounted State of the cable strain relief (1) is arranged on a tensile force receiving surface (21) of the tensile force forwarding element (20), characterized in that the tensile force forwarding element (20) is formed by a spring element (22) and an end sleeve (30) and the spring element (22) between the at least one tensile force dissipation surface (12) and the end sleeve (30) are arranged and the spring element (22) forms the tensile force receiving surface (21) on the cable clamp element side and, in the assembled state of the cable strain relief (1), rests against the end sleeve (30) with the side facing away from the cable clamp. Cable strain relief (1). Claim 1 , wherein the first and second cable clamp elements (10, 11) each have a first section (13) with a screw head support surface (14) and a through opening, a second section (15) which has a peripheral section of the cable (2) in the assembled state of the cable strain relief (1) and has a third section (16) with a through hole with an internal thread, the third section forming the tensile force dissipation surface (12). Cable strain relief (1). Claim 2 , wherein the second section (15) of the first and second cable clamp elements (10, 11) each form at least one elevation (17), which in the assembled state of the cable strain relief (1) points in the direction of the cable (2). Cable strain relief (1) according to one of the previous ones Claims 1 until 3 , wherein the spring element (22) forms a centrally arranged recess through which the cable (2) runs at least in the assembled state of the cable strain relief (1) and wherein the spring element (22) at least in the assembled state of the cable strain relief (1) in the direction of a cable axis is compressed. Cable strain relief (1) according to one of the previous ones Claims 1 until 4 , with a sealing clamping cage (33) and a seal, the end sleeve (30) forming a cavity (32) with an internal thread for receiving a sealing clamping cage (33) on its side facing away from the cable clamp element, in which the sealing clamping cage is at least in the assembled state of the cable strain relief (1). (33) presses the seal against the cable (2) in order to seal the side of the end sleeve (30) facing the cable clamp element from the side of the end sleeve (30) facing away from the cable clamp element and to center the cable (2) relative to the tensile force receiving surface (21). Cable strain relief (1) according to one of the previous ones Claims 1 until 5 , wherein the end sleeve (30) forms a circumferential wall (31) which, at least in the assembled state of the cable strain relief (1), surrounds the first and second cable clamp elements (10, 11) in the cable circumferential direction. Plug connector with cable strain relief (1). Claim 6 , wherein the plug connector comprises a sleeve with an external thread, onto which the end sleeve (30) with an internal thread can be screwed along the wall (31) in a mounted state of the plug connector.

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