EXPANSION PLUG ASSEMBLY

Abstract

The present disclosure relates to an expansion plug assembly, comprising a body with a channel to be plugged, the channel being defined by a channel wall which has a circumferential groove, a diameter of the groove being larger than a diameter of the channel, and a bushing for inserting into the channel of the body. The bushing comprises an orifice with a partially surrounding bushing wall, the bushing wall having a first bushing wall section having at least a bendable fin for forming a form-fit connection with the circumferential groove, and a tapered pin configured to bend up the bendable fin when inserted into the orifice of the bushing such that the bendable fin forms the form-fit connection with the circumferential groove when the bushing is inserted into the channel.

Claims

1. An expansion plug assembly, comprising: a body with a channel to be plugged, the channel being defined by a channel wall which has a circumferential groove, a diameter of the circumferential groove being larger than a diameter of the channel, a bushing for inserting into the channel of the body, the bushing comprising: an orifice with a partially surrounding bushing wall, the bushing wall having a first bushing wall section having at least one bendable fin for forming a form-fit connection with the circumferential groove, and a tapered pin configured to bend up the at least one bendable fin when inserted into the orifice of the bushing such that the at least one bendable fin forms the form-fit connection with the circumferential groove when the bushing is inserted into the channel.

2. The expansion plug assembly according to claim 1, wherein the bushing further comprises a second bushing wall section for forming a frictional connection with the channel wall.

3. The expansion plug assembly according to claim 1, wherein the first bushing wall section comprises between two and ten bendable fins disposed circumferentially around the orifice.

4. The expansion plug assembly according to claim 3, wherein the first bushing wall section comprises between four and eight bendable fins disposed circumferentially around the orifice.

5. The expansion plug assembly according to claim 4, wherein the first bushing wall section comprises six bendable fins disposed circumferentially around the orifice.

6. The expansion plug assembly according to claim 2, wherein the second bushing wall section is tapered.

7. The expansion plug assembly according to claim 1, wherein an inner surface of the bushing wall is tapered.

8. The expansion plug assembly according to claim 2, wherein an aperture angle of the second bushing wall section is smaller than an aperture angle of an inner surface of the bushing wall.

9. The expansion plug assembly according to claim 1, wherein the orifice is a blind hole and the bushing comprises a bottom wall forming an abutment surface for the tapered pin.

10. The expansion plug assembly according to claim 1, the channel has a bushing input side, where the bushing is inserted into the channel, wherein the form-fit connection with the circumferential groove is formed at a top abutment edge formed by the circumferential groove on a side of the circumferential groove facing the bushing input side.

11. The expansion plug assembly according to claim 2, wherein the channel has a bushing abutment side, where the bushing abuts when completely inserted into the channel, wherein the channel wall comprises a bottom abutment edge on the bushing abutment side, for forming a form-fit connection with the second bushing wall section.

12. The expansion plug assembly according to claim 2, wherein the second bushing wall section comprises a circumferential ridge configured to form the frictional connection with the channel wall.

13. The expansion plug assembly according to claim 12, wherein the circumferential ridge has a thread shape.

14. The expansion plug assembly according to claim 2, wherein the tapered pin has a first pin section with a first taper shape configured to bend up the at least one bendable fin when the tapered pin is completely inserted into the bushing, and a second pin section with a second taper shape configured to expand the second bushing wall section when the tapered pin is completely inserted into the bushing.

15. The expansion plug assembly according to claim 14, wherein the first taper shape of the first pin section has a larger aperture angle than the second taper shape of the second pin section.

16. The expansion plug assembly according to claim 1, wherein the bushing comprises at least one of a bendable non-thermally treated stainless steel and a carbon steel, of medium-to-high resistance with a bending capacity.

17. The expansion plug assembly according to claim 1, wherein the tapered pin comprises at least one of a hardened bearing steel and a tempered bearing steel.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0028] FIGS. 1A and 1B show a working principle of an expansion plug according to the state of the art.

[0029] FIGS. 2A and 2B show a working principle of another expansion plug according to the state of the art.

[0030] FIGS. 3A and 3B show a working principle of another expansion plug according to the state of the art.

[0031] FIG. 4 shows a sectional view of a body with a channel of the presently proposed expansion plug assembly according to an embodiment.

[0032] FIG. 5 shows a sectional view of a tapered pin partly inserted into a bushing of the presently proposed expansion plug assembly according to an embodiment.

[0033] FIG. 6 shows a sectional view of the presently proposed expansion plug assembly according to an embodiment when completely installed.

[0034] FIG. 7 shows a perspective view of the presently proposed expansion plug assembly according to an embodiment when completely installed.

DETAILED DESCRIPTION

[0035] FIGS. 4 to 7 illustrate different aspects of an embodiment of the presently proposed expansion plug assembly. As shown in FIG. 4, the expansion plug assembly comprises a body 1 with a channel 2. The channel 2 may be filled with a fluid that shall be prevented from leaking out of the channel 2 by the expansion plug assembly according to the present disclosure. The channel 2 is surrounded by a channel wall 21. The channel wall 21 comprises a circumferential groove 22 at one side of the channel 2. The groove 22 surrounds a groove section of the channel 2. In the groove section, a diameter of the channel 2 is larger than in a section of the channel 2 adjacent to the groove section. The groove 22 is disposed at a bushing input side 31 (see FIGS. 6 and 7). Spaced apart from the groove 22, the channel wall 21 comprises a bottom abutment edge 24.

[0036] As shown in FIG. 5, the expansion plug assembly further comprises a bushing 3 and a pin 5, wherein the pin 5 is adapted to be inserted into the bushing 3. The bushing 3 is adapted to be inserted into the channel 2. The bushing 3 has an orifice 4 with a partially surrounding bushing wall 41. The bushing wall 41 has a first bushing wall section 42 comprising bendable fins 43, for example four bendable fins 43, and a second bushing wall section 44 comprising a plurality of ridges 6. An inner surface 45 of the bushing wall has a taper shape, wherein the taper opens towards the first bushing wall section 42. At a bottom of the orifice 4 next to the second bushing wall section 44, the bushing 3 has a bottom wall 46. The pin 5 has a first pin section 51 with a first taper shape and a second pin section 52 with a second taper shape. The pin 5 can be inserted completely into the bushing 3 such that the pin 5 abuts against the bottom wall 46 of the bushing 3, the first pin section 51 is in frictional connection with the second bushing wall section 44 and the second pin section 52 is in frictional connection with the first bushing wall section 42.

[0037] FIG. 6 shows the mounted expansion plug assembly according to the embodiment in a sectional view. FIG. 7 shows the mounted expansion plug assembly according to the embodiment in a perspective view. The bushing 3 has been inserted into the channel 2 from a bushing input side 31. The bushing 3 abuts against the bottom abutment edge 24 of the channel wall 21. The pin 5 has been completely inserted into the bushing 3 such that the pin 5 abuts against the bottom wall 46 of the bushing 3. In this case, the second pin section 52 is disposed next to the first bushing wall section 42 with the fins 43. The fins 43 are bent open by the second pin section 52 having a maximum diameter of the pin 5. Thus, the first bushing wall section 42 increases in diameter, and the fins 43 insert into the groove 22 of the channel wall 21. This results in the formation of a form-fit connection between the fins 43 and the top abutment edge 23 of the groove 22. Thus, the bottom abutment edge 24 and the top abutment edge 23 prevent the bushing 3 from being ejected from the channel 2. Furthermore, the second bushing wall section 44 having a plurality of grooves 6 forms a frictional connection with the channel wall 21 which additionally inhibits a movement of the bushing 3 along the channel 2. The form-fit connection between the fins 43 and the top abutment edge 23 prevents the bushing 3 from being ejected under increased pressure independently of the material resistance, coupling clearances or surface roughness.