Title:
Tubular rivet
United States Patent 2366965


Abstract:
This invention relates to tubular rivets constructed so as to be upset by exerting an outward pressure upon the internal bore of the rivet, but more particularly to tubular rivets intended to be threaded upon a mandrel and upset by drawing from one end of the rivet to the other an enlarged...



Inventors:
Thomas, Johnson Stanley
Application Number:
US34642440A
Publication Date:
01/09/1945
Filing Date:
07/19/1940
Assignee:
AVIAT DEVELOPMENTS LTD
Primary Class:
Other Classes:
16/386
International Classes:
F16B19/10
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Description:

This invention relates to tubular rivets constructed so as to be upset by exerting an outward pressure upon the internal bore of the rivet, but more particularly to tubular rivets intended to be threaded upon a mandrel and upset by drawing from one end of the rivet to the other an enlarged head of the mandrel while exert'ng an opposing thrust against the end of the rivet towards which the head of the mandrel is drawn.

According to the present invention there is provided a tubular rivet whose stem is uniformly tapered externally so that the wall is thickened at the tail end of the rivet. The rivet may be upset by drawing a mandrel having a rigid pear-shaped head through the bore of the rivet so that an outward radial pressure is exerted by the mandrel head on the stem of the rivet throughout the whole or the greater part of its length, causing the stem to be expanded to a tight fit in the rivet hole. After the rivet has been upset and tne head of the mandrel reaches a position in line with the face of the workpiece remote from the rivet head, some of the metal of the rivet stem is drawn along by the mandrel head, so as to increase the radial pressure and ensure the filling of the rivet hole.

Typical forms of rivet according to the present invention and a method of upsetting the same are illustrated, by way of example, in the accompanying drawings, in which: Figures 1 to 12 illustrate in longitudinal section twelve forms of rivet constructed in accordance with the present invention, and Figures 13 and 14 illustrate sectional views indicating successive steps in the upsetting of a rivet in accordance with the present invention.

Figure 13 illustrates the rivet in position and the shank of the upsetting mandrel extending through the rivet, while Figure 14 illustrates a later stage of the upsetting operation.

Referring to the drawings, it will be seen that the form of rivet illustrated in Figure 1 is one in which the stem of the rivet has a tapered external surface A which terminates in a chamfered portion B and is provided at one end with a countersunk head C. The bore D of the rivet 's uniformly tapered throughout its length, the diameter of the bore being a minimum at the tail end of the rivet, thereby producing a rivet having a thickened wall at the tail end of the rivet.

Figure 2 illustrates a modified form of rivet to that illustrated in Figure 1 wherein the external configuration of the rivet is the same as that illustrated in Figure 1 but wherein the internal bore of the rivet comprises a cylindrical portion E adjacent to the head of the rivet and thereafter for the major portion of the length of the rivet a un'formly tapered portion D. The minimum diameter of the bore of the rivet is so arranged as to form a thickened wall at the tail end of the rivet.

Figure 3 illustrates a modified form of the rivet illustrated in Figure 1, wherein the external configuration of the rivet is the same as that illustrated in Figure 1 but wherein the internal bore of the rivet comprises a tapered portion D adjacent to the head of the rivet and thereafter a cylindrical portion E disposed adjacent to the tail of the rivet so as to form a thickened wall at the tail end of the rivet.

Figure 4 is a combination of the rivets illustrated in Figures 2 and 3 in which the external configuration of the rivet is the same as that illustrated in Figure 1, but wherein the internal bore comprises cylindrical portions E and F disposed respectively at the head and tail of the rivet and disposed between the two cylindrical portions E and F is a uniformly tapered portion D the minimum diameter of which is disposed adjacent to the cylindrical portion F adjacent to the tail end of the rivet. Further the tapered portion D extends over the greater part of the length of the internal bore and forms together with the cylindrical portion F a thickened wall at the tail of the rivet.

Figure 5 illustrates a rivet having an internal cylindrical bore G and a stem H, the external surface of which tapers externally over the whole of its length so as to-produce a thickened wall at the tail end of the rivet.

Figure 6 illustrates a rivet having an internal cylindrical bore G and a stem, the external surface of which is cylindrical at that portion K thereof which is adjacent to the head of the rivet, whereafter the stem tapers at the portion M over the greater part of the length of the stem to form a thickened wall at the tail end of the rivet.

Figure 7 illustrates a rivet having an internal cylindrical bore G and a stem, the external surface of which tapers at N from the head towards the tail for the greater part of the length of the stem whereupon the surface is cylindrical as at P. so that with the tapered portion above referred to a thickened wall is formed at the tail end of the rivet.

Figure 8 illustrates a rivet having an internal cylindrical bore G and a stem, the external surface of which is divided into three portions R, 2,860,965 II f 0 l s a 0 r t 1o ( t I I and T. The portion R of the stem adjacent othe head of the rivet is of cylindrical formaon, the portion S of the stem tapers outwardly owards the tail of the rivet and the portion T f the stem is of cylindrical formation. The ortions R and T of the stem are shaped so as to orm a thickened wall at the tail of the rivet 7hilst the tapered portion S is made of such a ength as to form the greater part of the length f the rivet. r10 gure 9 i llustrates a rivet wherein both the ternal bore V and the external surface W of the tem of the rivet taper in opposite directions so s to produce a thickened wall at the tail end of he rivet, but the external surface of the stem ýf the rivet is curved outwardly but yet may be nodifled in the manner indicated in Figures 6, 7 r 8 and further the internal bore of the rivet ay be modified in the manner indicated in Figares 2, 3 or 4 without in any way departin he spirit of the invention which s to produce t spirigt o twah which ithicen s to h e tl end aperi wa ch thickens at t he tail end ig the lltraterivet siir Figure 10 illustrates a rivet similar to that ilustrated in Figure 1 wherein the tapered interior f the vet is of a stepped formation and it is f the unvet is of a stepped formation and s it s o be understood that any of the tapered surfaces referred to with reference to Figures 1 to 4 may ie of stepped formation.

Figures 11 and 12 illustrate rivets in which the external surface tapers in the form of a curve imilar to that illustrated in Figure 9 so as to produce a thickened wall at the tail end of the rivet, the internal bore of the rivets being respectively curved and cylindrical.

Itively cve apnd tcyindrical. tehe It will be appreciated that the heads of the rivets may bte of any desired shape and that the tail end or the internal bore at the head rivet may be chamfered or not as desired without departing from the essence of the present inventin. of the remainder of the stem. tion.

A method of fixing the rivets according to the present invention is diagrammatically illustrated, by way of example, in Figures 13 and 14. A rivet for instance of the form illustrated in Figure Sinserted intof thwo oaxial holes drilled in two i insertd into two c oil holes drilled in two members I and 2 to be s eured together. The diameters of the holes are made slightly greater than that of the stem of the rivet thus leavin tan lehatn the betee of the wrivek thus leaing The heand C f the rivet s pressed against the outer surface of the member i by the nose 4 of a riveting machine of which only a part is illustrated. The shank 5 of a mandrel of the riveting machine is formed with an enlarged pear-shaped head 6, 1 and Is drawn through the rivet from the tail toward is the headrawn thereof th As the conical portion $ of the head of the mandrel is drawn through the rivet it causes the tail end 8 of the rivet to be expanded and upset into the position 9 illustrated in Figure 14. Further movement of the mandrel in the same direction expands the body of the rivet outwardly into contact with the sides of the hole-to fill the space 3 as indicated at 10 in Figure 14. During the passage of the mandrel through the bore of the rivet a ridge of metal I is formed in advance of the conical surface 6 of the mandrel head and, this is expanded outwardly to ensure the tightness of the rivet, the material of the rivet being suti-iently ductile to allow this action, To complete the fixing of the rivet the head of the mandrel is drawn completely through the rivet, Owing to its simple form most of the rivets 75 which constitute the subject matter of the present invention may as an alternative to machining be formed by pressing or stamping from blanks or tubes. With certain materials it may be advantageous to subject the rivets so formed to heat treatment to increase or restore their ductility.

In the examples of rivets hereinbefore described and illustrated the external tapered surface of the rivet has been indicated as a plane surface or surfaces. It is to be understood that the external tapered surface of the rivet may necessary be stepped in a similar manner to that indicated in the rivet illustrated in Figure 10 with regard to the internal tapered surface thereof.

What I claim as my invention and desire to secure by Letters Patent of the United States is: 1. A tubular rivet comprising an enlarged head from 0 and a stem, said stem being deformable when subjected to outward radial pressure to expand the stem to a tight fit within a rivet hole, the length of said stem exceeding the maximum exi ternal diameter thereof, and said stem being tap red externally toward the tail end of the rivet so that the wall of the rivet is thickened at the tail end thereof where the stem has an external diameter exceeding the external diameter of the remainder of said stem.

2. A tubular rivet comprising an enlarged head 0 and a stem, said stem being deformable when subjected to outward radial pressure to expand the stem to a tight fit within a rivet hole, the length of said stem exceeding the maximum external diameter thereof, and said stem being ta35 ternal diameter thereof, and said stem being tahe pered externally toward the tail end of the rivet over at least the greater part of the length thereof, so that the wall of the rivet is thickened at stem has an eternal diameter exeeding the eternal diamete 40 ternal diameter exceeding the external diameter 3. A tubular rivet comprising an enlarged head 3. A tubular riv stem being deformable when and a stem, said stem being deformable when subjected to outward radial pressure to expand 45 the stem to a tight fit within a rivet hole, the length of said stem exceeding the maximum xternal diameter thereof, and the exterior of said stem being tapered outwmardly toward the tail end of the rivet and having its bore uniformly n tera ahi is bre u m 50 tapered inwardly toward the tail end of the rivet over at least the greater part of the length thereof to form a thickened wall at the end of the rivet remote from the head, at which end the stem has an external diameter exceeding the external di55 ameter of the remainder of the stem.

4. A tubular rivet comprising an enlarged head and a stem, said stem being deformable when subjected to outward radial pressure to expand the stem to a tight fit within a rivet hole, the 60 length of said stem exceeding the maximum external diameter thereof, and said stem having an internal bore which is tapered inwardly toward the tail end of the rivet over the whole of the length thereof so that the portion of lesser 65 diameter of the bore is located at the end of the rivet remote from the head, the external surface of said stem being tapered outwardly toward the tail end of the rivet, so that the wall of the rivet is thickened at the tail end thereof where 70 the stem has an external diameter exceeding the external diameter of the remainder of the stem.

5. A tubular rivet comprising an enlarged head and a stem, said stem being deformable when subjected to outward radial pressure to expand the stem to a tight fit within a rivet hole, the length _ __ of said stem exceeding the maximum external diameter thereof, and the exterior, of said stem being tapered outwardly toward the tail end of the rivet, the bore of said stem being cylindrical for a part of the length thereof so that the wall of the rivet is thickened at the tail end of the rivet where the stem has an external diameter exceeding the external diameter of the remainder of the stem.

6. A tubular rivet comprising an enlarged head and a stem, said stem being deformable when subjected to outward radial pressure to expand the stem to a tight fit within a rivet hole, the length of said stem exceeding the maximum external diameter thereof, the-exterior of said stem being tapered outwardly toward the tail end of the rivet over at least the greater part of the length thereof, the bore of the stem being cylindrical to form a thickened wall at the tail end of the rivet where the stem has an external diameter exceeding the external diameter of the remainder of the stem.

7. A tubular rivet comprising an enlarged head and a stem, said stem being deformable when subjected to outward radial pressure to expand the stem to a tight fit within a rivet hole, said rivet having an internal bore which is tapered over a portion of the length thereof and inwardly toward the tail end of the rivet and is cylindrical for the remainder thereof, the exterior surface of the stem being tapered outwardly toward the tail end of the rivet to form a thickened wall at said tail end where the stem has an external diameter exceeding the external diameter of the remainder of the stem.

8. A tubular rivet comprising an enlarged head and a stem, said stem being deformable when subjected to outward radial pressure to expand the stem to a tight fit within a rivet hole, the length of said stem exceeding the maximum external diameter thereof, and the bore of said stem being substantially cylindrical, the exterior of said stem being tapered uniformly toward the tail end of the rivet over the greater part of its length to form a thickened wall at the tail end of the rivet where the stem has an external diameter exceeding the external diameter of the remainder of the stem.

9. A tubular rivet comprising an enlarged head and a stem, said stem being deformable when subjected to outward radial pressure to expand the stem to a tight fit within a rivet hole, the length of said stem exceeding the maximum external diameter thereof, the bore of said stem being tapered inwardly toward the tail end of the rivet, and the exterior of the stem being tapered uniformly outwardly toward the tail end of the rivet, both tapers extending over at least the greater part of the length of the stem to form a thickened wall at the tail end of the rivet where the stem has an external diameter exceeding the external diameter of the remainder of the stem.

10. A tubular rivet comprising an enlarged head and a stem, said stem being deformable when subjected to outward radial pressure to expand the stem to a tight fit within a rivet hole, the length of said stem exceeding the maximum external diameter thereof, said stem being tapered both internally and externally over the greater part of the length thereof, the internal portion of said stem being tapered inwardly toward the tail end of the rivet and the external portion of said stem being tapered outwardly toward the tail end of the rivet, the remainder of the internal portion of said stem being cylindrical and the arrangement being such as to form a thickened wall to the tail end of the stem where the stem has an external diameter exceeding the external diameter of the remainder of the stem.

STANLEY THOMAS JOHNSON.