Rivet for blind fasteners, associated setting tool and method for setting such a rivet

Patent metadata

Field	Value
Publication number	US-9669457-B2
Application number	US-201514596810-A
Country	US
Kind code	B2
Filing date	Jan 14, 2015
Priority date	Jan 14, 2014
Publication date	Jun 6, 2017
Grant date	Jun 6, 2017

Abstract

A rivet for blind fastening may include a screw with a handling element, a break groove, a head separated from the handling element by the break groove, and a threaded part. The rivet may also include a sleeve with a collar and a tubular shank having an internal thread intended to come into engagement with the threaded part of the screw. The handling element includes a first handling portion able to guide introduction of the rivet in a setting tool, and a second handling portion able to transmit a torque, the two handling portions being separated by a blocking portion able to limit an axial movement of the rivet in a setting tool. A setting nose may be used for installing such a rivet, and the rivet, setting nose and a setting method can be used in the assembly of aircraft structures.

First claim

The invention claimed is:

1. Rivet comprising a screw with a handling element, a breaking groove designed to hold under a tensile stress and break under a torsional stress, a head separated from the handling element by the breaking groove, a smooth shank and a threaded portion; a sleeve comprising a collar able to receive the head, and a tubular shank comprising an internal thread intended to come into engagement with the threaded portion of the screw, characterized in that the handling element of the screw comprises a first handling portion having a smooth outer circular cylindrical surface able to guide the introduction of the rivet into a setting tool, and a second handling portion able to transmit a torque, the two handling portions being separated by a blocking portion able to limit an axial motion of the rivet in a setting tool.

2. Rivet according to claim 1 , wherein the blocking portion comprises a cylindrical median portion and is connected to each handling portion by a radiused portion.

3. Rivet according to claim 1 , wherein the sleeve comprises two welded elements.

4. Rivet according to claim 1 , wherein the sleeve comprises a zone for bulb formation with an elastic strength less than an elastic strength of the rest of the sleeve.

5. Rivet according to claim 1 , wherein the sleeve comprises at least one compression groove made on an outer portion of the tubular shank of the sleeve between the collar and the zone for formation of the bulb.

6. Rivet according to claim 1 , wherein the torque is transmitted by means of splines with polygonal faces or a cylindrical face.

7. Rivet according to claim 1 , wherein the first handling portion comprises a chamfer.

8. Rivet according to claim 1 , wherein the sleeve comprises an end portion opposite the collar, with an outer diameter smaller than the outer diameter of the shank.

9. A rivet and setting nose combination for installing the rivet, the combination comprising the rivet according to claim 1 , and wherein the setting nose includes a cylindrical body with a pierced front face, a tubular sheath arranged inside the body, a mouth piece arranged inside the sheath and defining an inner passage, characterized in that the mouth piece comprises two receiver portions for the handling element of the rivet, with a form complementary to said rivet handling portions, at least one of the receiver portions being able to transmit a torque, said receiver portions being axially separated by a median portion comprising at least one element movable radially in the inner passage and able to limit an axial motion of the rivet.

10. The rivet and setting nose according to claim 9 , wherein the torque is transmitted by means of splines, by means of polygonal faces or by a roller cage.

11. The rivet and setting nose according to claim 9 , wherein the median portion comprises at least one housing in which the radially movable element is housed.

12. The rivet and setting nose according to claim 9 , wherein an elastic means radially compresses the movable element towards the inside of the mouth piece.

13. The rivet and setting nose according to claim 9 , wherein the mouth piece is movable axially and in rotation inside the sheath.

14. Method for installation of a rivet according to claim 1 , using a setting nose with the rivet, wherein the setting nose includes a cylindrical body with a pierced front face, a tubular sheath arranged inside the body, a mouth piece arranged inside the sheath and defining an inner passage, wherein the mouth piece includes two receiver portions for the handling element of the rivet, with a form complementary to said handling portions, at least one of the receiver portions being able to transmit a torque, said receiver portions being axially separated by a median portion having at least one element movable radially in the inner passage and able to limit an axial motion of the rivet, characterized in that the method comprises the steps of:
engagement of the setting nose with the handling element of the screw,
axial traction on the handling element and formation of a bulb on the sleeve,
screwing of the screw into the sleeve and breakage of the handling element of the screw at the level of the break groove,

characterized in that during the step of engagement of the setting nose with the handling element of the screw, a radially movable element limits an axial motion of the rivet in the setting nose.

15. Installation method according to claim 14 , characterized in that during the steps of bulb formation, screwing of the screw and breakage of the handling element, the handling portions of the screw are contained in the receiver portions of the mouth piece, the blocking portion of the screw rests against the movable element, and the mouth piece is contained inside the sheath so as to prevent any radial movement of the movable element.

16. Rivet comprising a screw with a handling element, a breaking groove designed to hold under a tensile stress and break under a torsional stress, a head separated from the handling element by the breaking groove, a smooth shank and a threaded portion; a sleeve comprising a collar able to receive the head, and a tubular shank comprising an internal thread intended to come into engagement with the threaded portion of the screw, characterized in that the handling element of the screw comprises a first handling portion having an outer surface with splines extending longitudinally and the first handling portion configured to be able to guide the introduction of the rivet into a setting tool, and a second handling portion able to transmit a torque, the two handling portions being separated by a blocking portion able to limit an axial motion of the rivet in a setting tool.

Assignees

• Lisi Aerospace

Inventors

• Bigot Frederic
• Couderc Jerome
• Gay Olivier
• Pailhories Guy

Classifications

• B21J15/043 Primary

  by pulling a mandrel · CPC title

• B25B27/0007

  Tools for fixing internally screw-threaded tubular fasteners · CPC title

• F16B19/1072

  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 Primary

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

• B21J15/12

  with tools or tool parts having a movement additional to the feed movement, e.g. spin {(B21J15/027 takes precedence)} · CPC title