US1611942A - Hollow rivet and process for making same - Google Patents

Description

Dec. 28, 1926. 1,611,942

L. M. PERSONS HOLLOW RIVET AND PROCESS FOR MAKING SAME Filed 001:. 20. 1.920

Patented Dec. 28, 1926.

miwanncn iairnnsons, or corner, rumors, ASSIGNOB'TO coox nmc'rarc com- PANY, OI CHICAGO, ILLINOIS,

A CORPORATION OF ILLINOIE.

, HOLLOW BIVET AND YBOCESS FOR MAKING BAKE.

Application filed Qctober 20, 192). Serial No. 418,308.

' My invention relates to split tubular rivets and the roc'ess for making. same.'

One 0 ject of my invention is the provision of a simple and eflicient tubular rivet capable of being easily expanded.

Another object of my invention is the provision of a tubular rivet internally threaded and capable of being expanded by adjusting a screw slightly larger than the internal diameter of the rivet.

A further object is the provision of a tubular rivet formed of sheet material having the threads formed by stamping serrations in the sheet material before the latter is made into tubular form.

A still further object is the provision of a simple and efiicient method of making rivets, such as above referred to. 7

Other objects will appear hereinafter.

An embodiment of my invention is shown in the accompanyin drawing, forming a part of this specification, and in Which Fig. 1 is a perspective view of a blank from which my tubular rivet is formed;

Fi 2 is a similar view of the blank having t e serrations formed therein and the longitudinal edges bent up;

F i 3 is a similar view showing the tubular rivet completely formed;

Fig. 4 is an enlarged fragmental section of a motor core having a tubular rivet therein embodying my invention;

Fig. 5 is a fragmental section, more or less diagrammatical, illustrating the method of forming my improved rivet; and

Fig. 6 is an elevation, more or less diagrammatical, illustrating the finishing process of making my im roved rivet.

My improved rivet as the advantage that it can be made very economically, much more so that where the tubular rivet must be made from a tube and internally threaded with dies.

In forming my rivet I first cutout a blank, such as indicated in Fig. 1, of the desired size to give a finished rivet in the size to be made. The next step in forming the rivet is to place it in the position indicated in Fig. 5 at 7 in a forming die 8. The punch 9 is then brought down onto the blank 7 pressing it from its dotted line position to its full line osition shown in Fig. 5. The punch 9 an die 8 are so formed that the serrations 10, clearly indicated in Fig. 2, will be formed. At the same time the die 8 and punch 9 will turn up the longitudinal edges 11 of the blank, as indicated in Fig. 2. The blank is next placed in a die, such as indicated in Fig. 6, and upon members 12 of such dies being forced in the directions of the arrows 13 the blank will be bent from itglfull line position to that indicated in dotte lines in said Fig. 6, thus completing the formation of the split tubular rivet with its internal threads.

This rivet will be useful in many places and I find it particularly adaptable for securing the laminations of motors, dynamos, and the like, together. In Fig. 4 I have indicated the usual core laminations 14 of a motor which are provided with registering perforations 15 therein for receiving a rivet to secure such laminations together. With the 'use of my improved rivet the latter is placed in the perforations 15 and its ends riveted in the usual manner. After the rivet has been riveted screws 16 are passed through the cover members 17 of the usual motor, or the like, constructions and threaded into the serrations 10 of my improved rivet. In forming the serrations 10 it will be understood they are to be made so that when finished the screw threads formed thereby will have the same pitch as the screws 16 to be used.

I preferably use screws 16 slightly larger than the internal diameter of the split rivets so that in forcing the screws into said rivets the latter will be expanded into close contact with the walls of perforations 15. The rough ed es 18 of the rivet will also tend to cut into t e walls of the perforations 15 and facilitate holding the rivet against rotation while the screws 16 are being adjusted into or out of position.

In Fig. 4 I have indicated a screw 16 in each end of one of my improved rivets. This expands both ends of the rivet and binds all of the laminations together. One of the screws 16 holds the laminations 14 up 1.

laminations, of a tubular rivet extending through registering openings therein and having the ends thereof beaded, said rivet no ill laminations with registerin having one side longitudinally split to permit expansion thereof, frame members en-.

closing said laminations and screws threaded core having a perforation therein, a tubularrivet in the perforation having beaded ends engaging the surface of the outermost laminations, and a wedge member disposed in the tubular rivet holding the latter in close contact with the walls of said rforation. V 3. In combination, a plurality of core perforations therein, a split tubular rivet 1n the perforations comprising a continuous sheet metal plate having a smooth outer surface, and a screw threaded in the tubular rivet adapted to expand the latter tightly against the laminations.

4. In combination, a plurality of core laminations with registering perforations therein, a split tubular rivet in said per- -tions together comprising riveting a split tubular rivet through the core laminations and then expandin the tubular rivet into close contact. with t e laminations by forcing a wedge into the tubular rivet.

6. The method of locking core laminations together comprising riveting a split tubular rivet through the laminations and then forcing a screw slightly larger than the internal diameter of the tubular rivet into the latter for expanding such tubular rivet into close contact with the laminations.

In testimony whereof I have signed my name to this specification on this 28th day of September, A. D. 1920.

LAWRENCE M. PERSONS.

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