GB2095354A - Coupling for a flexible hose - Google Patents

Abstract

A coupling for a flexible hose made of polymer material of high molecular weight, comprising a clamping ring by means of which a wall portion of the hose, which is radially extended when the hose wall is deformed, is urged to an annular shoulder of an axially-secured support, characterised in that the surface (17) of the clamping ring (13) subtends an acute angle ( alpha ) relative to the axis of symmetry (a-a) of the coupling and is spaced from the annular edge of the annular shoulder (22) of the support (w) by a distance which is smaller than the thickness of the undeformed wall of the hose (10) and in that, in use, the extended wall portion (10a) lies on said surface (17). <IMAGE>

Description

SPECIFICATION Tension-relieving means for a flexible hose The present invention relates to a tensionrelieving means for a flexible hose made of highpolymer material, comprising a clamping ring by means of which a wall portion of the hose, which is radially extended when the hose wall is deformed, is pressed rearwardly against the annular shoulder of an axially secured abutment.

Atension-relieving means ofthistype is required, for example, for a hose which encloses delicate electrical leads, which are laid slackly to a greater or lesser degree, and thereby protects them from mechanical stresses. In many cases, such leads extend from an electrical appliance and the hose which surrounds them is axially secured to the appliance wall.

However, tension-relieving means of this type are also required for hoses which transport fluid media, the hoses being connected, for example, to a hydraulic block and being supplied therefrom.

Even hoses on hose couplings must be able to be stressed to axial tension and be relieved of tension accordingly. In a known tension-relieving means of the above-mentioned type which is formed on a hose coupling, the abutment comprises an external annular groove into which is radially pressed the wall of the hose, drawn over the radiallysymmetrical abutment, by means of a belt and the wall is secured in the deformed position by means of a clamping ring. The pressing of the hose material into the groove thereby necessarily presupposes a radial movement of the belt, and this is not possible without more complex technical aids (German Offenlegungsschrift2 109 974).

The invention seeks to develop a tension-relieving means of the above-mentioned type in such a mannerthatthe radial extension of the hose wall may be achieved with relatively little manufacturing outlay and without impairing the ability of the means to relieve tension, and so that good conditions therefor exist for simple assembly and economical manufacture.

According to the present invention there is provided tension-relieving means for a flexible hose made of polymer material of high molecular weight, comprising a clamping ring by means of which a wall portion of the hose, which is radially extended when the hose wall is deformed, is urged to an annular shoulder of an axially-secured support, characterised in that the surface of the clamping ring subtends an acute angle relative to the axis of symmetry of the tension-relieving means and is spaced from the annular edge of the annular shoulder of the support by a distance which is smaller than the thickness of the undeformed wall of the hose, and in that, in use, the extended wall portion lies on said surface.

So asto attach the tension-relieving means subsequentlyto a hose surrounding electrical leads, it is advantageous to use a clamping ring which is axially split, at least partially, and which may be fully split, if required, by hand, e.g. with a knife. After it has been fully split axially, such a clamping ring permits the electrical leads, which are accommodated in the hose, to be inserted into the clamping ring via the axial gap without their having to be previously removed and without subsequent time-consuming axial threading during the assembly of the tensionrelieving means.

When the tension-relieving means is attached to a hose which transports fluid media, it is important, for sealing purposes, that the annular edges of the two annular shoulders of the abutment are pressed into the deformed wall of the hose.

Further embodiments of the invention are found in the subclaims.

The invention will be described further, by way of example, with reference to the accompanying drawings, in which: Fig. 1 is a side elevation partly in longitudinal section through an embodiment of tension-relieving means; Fig. 2 is an end elevation of the clamping ring viewed from the right-hand side of its position in Fig. 1; Fig. 3 is an elevation partly in section taken on the line III-ill of Fig. 2 of the split tensioning ring shown in Fig. 2, and Fig. 4 illustrates a rotatable mandrel having an abutment shoulderforthe clamping ring, it to be inserted into the hose by the axial slipping-on of the hose.

Atension-relieving means is illustrated which is intended for use with a flexible hose 10 made of polymer material of high molecular weight and comprises a clamping ring 13 which is disposed within the hose 10. The surface 17 of the clamping ring 13 subtends an acute angle a relative to the axis of symmetry a-a of the tension-relieving means. The surface 17 is spaced from the annular edge of the annular shoulder 22 of the abutment w by a distance which is less than the thickness of the undeformed wall of the hose 10. A wall portion 10a of the hose 10, which is radially extended when the hose wall is deformed, is pressed behind (beyond and against) the annular shoulder 22 of an axially secured support or abutmentw of the tension-relieving means.

The radially extended wall portion 1 Oa lies on the surface 17 of the clamping ring 13. The radiallysymmetrical abutment w is formed by two sleeves, namely tension-relieving sleeve 12 and securing sleeve 11 which are interconnected to each other by portions 11b, 12a. The tension-relieving sleeve 12 which surrounds the hose 10, is in engagement with the internal thread 1 1d of the securing sleeve by means of an external thread. The securing sleeve 11 has an axial portion 1 lea having a smaller internal diameter and an external thread Ilf.

The clamping ring 13 is an injection moulding made of a polymer material of high molecular weight with a greater rigidity than the rigidity of the material of the hose. The annular shoulder 22 which is rearwardly engaged by the radially extended wall portion 1 Oa, of the abutment w is the front edge of the tension-relieving sleeve 12. This annular shoulder 22 is axially spaced from an annular shoulder 19 of the securing sleeve 11-the axial space corresponding to approximately three times the thickness of the wall of the hose 10. The two annular shoulders 19 and 22 each lie perpendicular to the axis of symmetry a-a.

The annular edges of these annular shoulders 19,22 are pressed into the deformed wall of the hose 1cud.

The external surface 17 of the clamping ring 13 subtend an angle a of approximately 10#rnlativetoThe inner surface 18 which extends parallel to the axis of symmetrya-a. The inner diameter of the tension relieving sleeve 12 corresponds to the inner diameter of the securing sleeve 11 in the portion 1 lea and is slightly larger than the external diameter of the hose 10. The frontedge 14 of the clamping ring 13 isaxially spaced from the annular shoulder 19 of the securing sleeve 11, this axial space being substantially smaller than the thickness of the wall of the hose 10.

The clamping ring 13 overlaps the tension-relieving sleeve 12 in the axial direction. The radial dimensions of the annular shoulders 19, 22 each correspond to approximately half the thickness of the wall of the hose. The maximum diameter of the clamping ring 13 in the region of the front edge 14 corresponds approximately to the diameter of the hose in the undeformed region, while the inner diameter of the clamping ring 13 is slightly smallerthan the inner diameter of the hose in the unextended region. The annular edge 15 of the clamping ring 13, remote from the connection side of the tension-relieving means, passes over an inclined face 16 into its surface 17. The securing sleeves 11 and the tensionrelieving sleeve 12 are each provided with a multiple edge 1 ic or 12b respectively for manipulation by a tool.As can be seen from Fig. 3, the clamping ring 13 has an axial gap 211 which extends from the outside radially inwardly and terminates some distance from the inner surface 18. The wall 13a, which spans the gap 211 in the gap region, permits the clamping ring to split fully axially in a relatively simple manner in the region of the gap 211. A fully axially split clamp ing ring facilitates the subsequent assembly of a tension-relieving means on a hose which surrounds electrical leads because these leads may be inserted into the clamping ring 13, via the axial gap, without being previously removed from their points of connection, and the clamping ring may then be brought into its predetermined position within the tensionrelieving means.

If the clamping ring is required for relieving the pressure of a hose which transports fluid media, the sealing quality of the internal surface 18 of the clamping ring 13 is not impaired by the partial gap 211 which serves merely to facilitate the completion of the gap if the tension-reliveving means is subsequently mounted on a hose surrounding electrical leads.

With such a tension-relieving means for a hose surrounding electrical leads, the abutment w is in engagement, via an external thread Ilf, with a threaded ring 20 which reaches behind a wall 21 of an appliance wall (not shown in full) so as to axially secure the tension-relieving means as shown in Fig.

1. In such a case, the portion 1 la of the abutment w attached to the appliance passes through a recess formed in the plane or flat appliance wall 21. An annular shoulder 1 lie of the abutment w thereby abuts, for centering purposes, against an external face of the wall 21 of the appliance and the shoulder of the threaded ring 20 abuts against the inside surface of the appliance wall.

With a tension-relieving means for a hose transporting fluid media, the external thread 1 of the abutment w is in sealingly threaded engagement with ahydraulic block containing the hydraulic medium.

The tension-relieving means is assembled in the following stages: The tension-relieving sleeve 12 is first pushed onto the end of the hose for a distance which corresponds approximately to the axial dimension of the tension-relieving sleeve 12. Subsequently, the clamping ring 13 is placed upon the end portion 23a of a substantially cylindrical mandrel 23 which is held by the chuck of a mechanical rotary drive. The clamping ring 13 is attached axially until its front end 14 abuts an annular shoulder 23c of the mandrel, this shoulder being formed at a transitional point between the portion 23a of the mandrel and a portion 23b of larger diameter. The end of the hose is then pushed onto the rotating clamping ring 13 until it reaches a position which substantially corresponds to the position as shown in Fig. 1 where it axially overlaps the tension-relieving sleeve 12.The rotation of the clamping ring and, where applicable, the lubrication of its external surface 17, make it easter to slip the end of the hose axially over the clamping ring 13, whereby the wall of the hose 10 becomes radially extended. After the hose 10 together with the clamping ring 13, has been removed from the mandrel 23, the end portion 1 Ob of the hose largely springs back into its original position, while the radially extended wall portion 10a remains in its deformed position.

The securing sleeve 11 is then screw-connected to the tension-relieving sleeve 12. The component of axial movement of the securing sleeve 11 which results from the screw-connection, causes the annular edge of the annular shoulder 19 of this securing sleeve to press into the wall of the hose, so that the annular edges of the two annular shoulders 19 and 22 are pressed into the wall of the hose. When fluid is transported through the hose, the deep abutment of the hose against the annual shoulder 19 provides a positive seal, while the abutment of hose material against the front edge of the tension-relieving sleeve 12 secures the hose 10 axially within the clamping connection. Because the distance between the surface 17 of the clamping ring 13 and the annular edge of the annular shoulder 18 is less than the thickness of the hose in the undeformed state, the hose cannot possibly be released axially from its clamping connection.

Claims (18)

1. Tension-relieving means for a flexible hose made of polymer material of high molecular weight, comprising a clamping ring by means of which a wall portion of the hose, which is radially extended when the hose wall is deformed, is urged to an annular shoulder of an axially-secured support, characterised in that the surface of the clamping ring subtends an acute angle relative to the axis of symmetry of the tension-relieving means and is spaced from an annular edge of the annular shoulder of the support by a distance which is smaller than the thickness of the undeformed wall of the hose, and in that, in use, the extended wall portion lies on said surface.

2. Atension-relieving means as claimed in claim 1, in which a tension-relieving sleeve, which surrounds the hose, has an external thread in threaded engagement with the internal thread of a mounting sleeve which has an axial portion with a reduced inner diameter and an external thread.

3. Atension-relieving means as claimed in claim 1 or 2, in which the clamping ring is an injection moulding made of a polymer material of high molecular weight with a higher degree of rigidity than the rigidity of the material of the hose.

4. A tension-relieving means as claimed in one of the preceding claims, in which the annular shoulder which is rearwardly engaged by the radially extended wall portion, is the leading edge of a tension-relieving sleeve and is axially spaced from an annular shoulder of a securing sleeve.

5. Atension-relieving means as claimed in claim 4, in which the annular shoulders each lie perpen dicular to the axis of symmetry of the tension relieving means and, in use, the annular edges of these annular shoulders are pressed into the deformed wall of the hose.

6. Atension-relieving means as claimed in one of the preceding claims, in which the external surface of the clamping ring defines an angle of approximately 10 relative to an inner surface thereof which extends parallel to the axis of symmetry.

7. Atension-relieving means as claimed in one of the preceding claims 2 to 6, in which the internal diameter of the tension-relieving sleeve corresponds to the internal diameter of the securing sleeve in the axial portion of reduced diameter and is slightly larger than the external diameter of the hose.

8. A tension-relieving means as claimed in one of the preceding claims 2 to 7 in which the front edge of the clamping ring is axially spaced from the annular shoulder of the securing sleeve, this axial space being smaller than the thickness of the wall of the hose, and in which the clamping ring overlaps the tension-relieving sleeve in the axial direction.

9. Atension-relieving means as claimed in one of the claims 4 to 8, in which the radial dimensions of the annular shoulders each corresponds to approximately half the thickness of the wall of the hose with which the means is to be used.

10. Atension-relieving means as claimed in one of the preceding claims, in which the clamping ring has a gap which extends from outside radially inwardly but terminates some distance from the internal surface.

11. A tension-relieving means as claimed in one of the preceding claims, in which the maximum diameter of the clamping ring corresponds approx imatelytothe diameter of the hose in the undeformed region.

12. Atension-relieving means as claimed in one of the preceding claims, in which the internal diameter of the clamping ring is slightly smaller than the internal diameter of the hose in the unextended region, and in which the annular edge of the clamping ring remote from the connection side of the tensionrelieving means, passes over an inclined face into its surface.

13. Atension-relieving means as claimed in one of the preceding claims 2 to 12, in which the securing sleeve and the tension-relieving sleeve each have a multiple edge for the attachment of tools.

14. Atension-relieving means for a hose surrounding electrical leads as claimed in one of the preceding claims, in which the abutment is engageable, via an external thread, with a threaded ring which is locatable behind a wall of an appliance with which the tension-relieving means is to be used so as to axially secure the tension-relieving means.

15. Atension-relieving means as claimed in claim 14, in which a portion of the abutment attached to the appliance passes through a recess formed in the flat appliance wall, whereby an annular shoulder of the abutment abuts, for centering purposes, against an external face of the appliance wall and the shoulder of the threaded ring abuts against the inside of the appliance wall.

16. Atension-relieving means for a hose conducting fluid media according to one of the claims 1 to 14, in which the external thread of the abutment is, in use, in sealingly threaded engagement with a hydraulic block containing the hydraulic medium.

17. A method of manufacturing a tension relieving means, corresponding to one of the preceding claims 1 to 16, characterised in that the hose wall is allowed to slide onto the inclined surface of the axially stationary and rotating clamping ring because of the axial advance of the hoseforthe radial extension of the hose with the formation of the radially extended wall portion.

18. Atension-relieving means substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.