Blind type removable fixing device, assembly comprising at least one such fixing device and method of dismantling such a fixing device

Patent metadata

Field	Value
Publication number	US-12540638-B2
Application number	US-202418916784-A
Country	US
Kind code	B2
Filing date	Oct 16, 2024
Priority date	Oct 18, 2023
Publication date	Feb 3, 2026
Grant date	Feb 3, 2026

Abstract

A fastening device for keeping at least first and second parts assembled, the fastening device comprising a tubular body passing through the first and second parts, an expansion nut and a screw that is seated in the tubular body and cooperates with the expansion nut. To facilitate the removal of the fastening device, the screw has at least one shape, such as a recess positioned on the transverse face thereof, to prevent it from rotating using a first tool, and the expansion nut has at least one shape, such as a flat, to unscrew it using a second tool. Also an assembly comprising at least one such assembly device as well as a removal method.

First claim

The invention claimed is:

1 . A fastening device for keeping at least first and second parts assembled, each of which has a through-hole and a bearing surface into which the through-hole opens, said fastening device comprising:
a tubular body; an expansion nut; and a screw, the tubular body extending between a first end and a second end and configured to be seated in the through-holes of the first and second parts, the first end of the tubular body cooperating with the expansion nut, the second end of the tubular body having a head configured to bear against the bearing surface of the first part, the expansion nut extending between a first end and a second end, having at least one threaded section and an axis of revolution, the expansion nut configured to expand to form a bulb when subjected to a compressive force between the first and second ends thereof, the screw having a shank extending between a first end and a second end, an axis of revolution, and an end face at the first end of the shank, the shank comprising a threaded section which cooperates with the threaded section of the expansion nut, the second end of the shank having an enlarged shape bearing against the tubular body, wherein the screw has at least one shape, on a transverse face of the shank, configured to cooperate with a first tool to prevent the screw from rotating about the axis of revolution thereof with respect to the first tool, wherein the expansion nut has at least one shape designed to cooperate with a second tool to prevent the expansion nut from rotating about the axis of revolution thereof with respect to the second tool, wherein the expansion nut further comprises a lateral face connecting the first and second ends of the expansion nut, and at least one flat positioned on the lateral face, and wherein the lateral face comprises a plurality of flats regularly distributed about the axis of revolution of the expansion nut.

2 . The fastening device as claimed in claim 1 , wherein each flat is positioned closer to the first end of the expansion nut than to the second end of the expansion nut.

3 . The fastening device as claimed in claim 1 , wherein the shank further comprises a recess, coaxial with the axis of revolution of the screw, which opens into the transverse face and has a bottom and a lateral face connecting the bottom and the transverse face, the lateral face having at least one flat.

4 . The fastening device as claimed in claim 3 , wherein the recess comprises a plurality of flats regularly distributed about the axis of revolution of the screw.

5 . The fastening device as claimed in claim 1 , wherein the head is configured to allow the head to be prevented from rotating or to be driven in rotation using a tool.

6 . The fastening device as claimed in claim 5 , wherein the head of the tubular body extends between a first transverse face and a second transverse face, the second transverse face configured to bear against the bearing surface of the first part, and
wherein the head comprises a first section of prismatic cross-section which extends from the first transverse face and a second section which extends between the first section and the second transverse face, the second section larger in cross-section than the first section.

7 . An assembly comprising:
a first part, a second part, and at least one fastening device as claimed in claim 1 configured to keep the first and second parts assembled.

8 . A fastening device for keeping at least first and second parts assembled, each of which has a through-hole and a bearing surface into which the through-hole opens, said fastening device comprising:
a tubular body; an expansion nut; and a screw, the tubular body extending between a first end and a second end and configured to be seated in the through-holes of the first and second parts, the first end of the tubular body cooperating with the expansion nut, the second end of the tubular body having a head configured to bear against the bearing surface of the first part, the expansion nut extending between a first end and a second end, having at least one threaded section and an axis of revolution, the expansion nut configured to expand to form a bulb when subjected to a compressive force between the first and second ends thereof, the screw having a shank extending between a first end and a second end, an axis of revolution, and an end face at the first end of the shank, the shank comprising a threaded section which cooperates with the threaded section of the expansion nut, the second end of the shank having an enlarged shape bearing against the tubular body, wherein the screw has at least one shape, on a transverse face of the shank, configured to cooperate with a first tool to prevent the screw from rotating about the axis of revolution thereof with respect to the first tool, wherein the expansion nut has at least one shape designed to cooperate with a second tool to prevent the expansion nut from rotating about the axis of revolution thereof with respect to the second tool, wherein the expansion nut further comprises a lateral face connecting the first and second ends of the expansion nut, and at least one flat positioned on the lateral face, and wherein each flat is positioned closer to the first end of the expansion nut than to the second end of the expansion nut.

9 . The fastening device as claimed in claim 8 , wherein the shank further comprises a recess, coaxial with the axis of revolution of the screw, which opens into the transverse face and has a bottom and a lateral face connecting the bottom and the transverse face, the lateral face having at least one flat.

10 . The fastening device as claimed in claim 9 , wherein the recess comprises a plurality of flats regularly distributed about the axis of revolution of the screw.

11 . The fastening device as claimed in claim 8 , wherein the head is configured to allow the head to be prevented from rotating or to be driven in rotation using a tool.

12 . The fastening device as claimed in claim 11 , wherein the head of the tubular body extends between a first transverse face and a second transverse face, the second transverse face configured to bear against the bearing surface of the first part, and
wherein the head comprises a first section of prismatic cross-section which extends from the first transverse face and a second section which extends between the first section and the second transverse face, the second section larger in cross-section than the first section.

13 . An assembly comprising:
a first part, a second part, and at least one fastening device as claimed in claim 8 configured to keep the first and second parts assembled.

Assignees

• Airbus Operations Sas
• Ateliers De La Haute Garonne Ets Auriol Et Cie Sas

Inventors

• Laurent Jean-Noël
• Bigot Julien
• Fouladoux Adrien
• Le Henaff Perig
• Maurice Arnaud
• Jehenne Bertrand
• Gutierrez Lucas
• Meric François

Classifications

• F16B19/1072 Primary

  the pull-mandrel or the like comprising a thread and being rotated with respect to the rivet, thereby mechanically expanding and fastening the rivet (nuts fastened by riveting F16B37/067) · CPC title

• F16B19/1054

  the pull-mandrel or the like being frangible · CPC title

• F16B19/1063

  with a sleeve or collar sliding over the hollow rivet body during the pulling operation · CPC title

• F16B35/045

  for retention or rotation by a tool (specially shaped heads of bolts or screws for rotation by a tool F16B23/00) · CPC title

• F16B31/021

  by means of a frangible part (F16B31/025, F16B31/028 take precedence; break members in torque limiters or torque indicators in wrenches or screwdrivers B25B23/1415) · CPC title