US1796852A - Method of riveting - Google Patents

Description

March 17, 1931. MCDONOUGH 1,796,852

METHOD OF RIVETING Filed May 31, 1927 Patented Mar. 17, 1931 UNITED STATES PATENT OFFICE JOHN MCDONOUGH, OF CHICAGO, ILLINOIS, ASSIGNOR TO WESTERN ELECTRIC COM- PANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK METHOD or RIVETING Applicationfiled May 31, 1927. Serial No. 195,379.

This invention relates to a method of riveting, and more particularly to a method of riveting pins in thin sheet materials.

Considerable difficulty has been experienced in riveting pins in thin sheet material due to a distortion of the sheet as the rivet expands and forces the material radially outward from the aperture in which the rivet is set. This is apparently due to the fact that the thin sheet material does not possess suflicient rigidity to retain the surrounding material in its original plane when it is attempted to draw the metal of the sheet in the vicinity of the aperture. Objects of this invention are to provide a method of obviating difiiculties heretofore experienced and making it possible to rivet pins in thin sheet material without distorting the sheet.

The invention contemplates the provision of a method in which the metal immediately surrounding the aperture in the sheet metal is formed so as to extend out of the plane of the sheet as the rivet is expanded to avoid a radial expansion of the material in the plane of the sheet. In accordance with one embodiment of the invention, the metal of the pin being riveted is drawn in such a manner as to cause the sheet metal adjacent the aperture in which the pin is being riveted to be drawn out of the plane of the sheet.

It is believed that a complete understanding of the invention may be had by reference to the following description taken in conjunction with the accompanying drawing which illustrates one embodiment of the invention as applied to attaching pins to calling dials for automatic telephones, in which Fig. 1 is a plan view of a die and its su port showing an unfinished dial partial y broken away in a position ready to be worked upon;

Fig. 2 is a fragmentary view of a riveting machine with a sectional view of the die and its support taken on line 22 of Fig. 1;

Fig. 3 is an enlarged fragmentary sectional view through the center of a rivet showing the rivet in a sheet of material at the beginning of the riveting operation, and

Fig. 4 is a view similar to Fig. 3 showing the rivet after the riveting operation.

Referring to the drawing in which the same reference characters designate similar parts in the several views, a riveting machine is designated generally at 7 and comprises a bracket 8 upon which a die support 9 is rotatably mounted and held in position by a pin- 11 fixed in the bracket. An arm 12 of the machine carries a compressed air cylinder 13 for operating a reciprocating hammer 14 through the medium of the compressed air which is supplied through a tube 15 from a source of compressed air (not shown). Inasmuch as any suitable compressed air cylinder and hammer may be employed they have not been shown in detail.

The die support 9 is provided with an annular groove 16 in which a similarly shaped die 17 is carried. The die is made of an annular shape in the present instance for the reason that the embodiment of the invention illustrated is adapted to rivet pins 10 in calling dials 18 which have an annular shape as used in automatic telephone systems. The die is provided with three tubular holes 19 corresponding to the number of pins to be riveted into a calling dial and each hole is surrounded at its upper end by a boss 21 having a slightly convex surface so as to form a shearing edge around the hole.

The pins 10 used in the riveting operation comprise a head 22, an enlarged portion which may be slightly tapered and ending in a shoulder 24, and a straight reduced portion 25. In order to rivet the pins in a calling dial, a dial with three apertures provided therein is placed on the die 17 in suclra position that the apertures in the dial coincide with the tubular holes 19 in the die. A pin is placed in each hole with the reduced portion inserted in the hole and the shoulder of the enlarged portion resting upon the boss 21. The die support is then rotated until a pin is directly under the hammer, when com-. pressed air is admitted to the cylinder 13 by means (not shown) to cause the reciprocating hammer to perform the riveting operation. It will be noted that in the beginning of the riveting operation the dial 18 as well as the shoulder 24 of the pin rest upon the boss 21,

but when the shoulder is being sheared from r the straight portion it is also turned outwardly and upset, thereby turning the edge of the material of the dial surrounding the aperture and bending the material out of the plane of the dial as shown in Fig. 4 of the drawing. By thus bending the material out of the plane of the dial the distorting radial strains adjacent the aperture in the dial are avoided when the pin is radially expanded in the riveting operation.

- It will be understood that the embodiment of the invention herein described and illustrated is merely a convenient and useful form of the invention, which is capable of many other modifications without departing from the spirit and scope of the invention.

WVhat is claimed is:

1. A method for riveting a shank to a thin sheet of metal, consisting in providing a rivet having a reduced shank at one end, a head at the other end, and an intermediate enlarged shank forming a shoulder between it and the reduced shank, providing a thin sheet of metal having an aperture, placing the rivet through the aperture, with the walls of the aperture closely embracing the enlarged shank at the shoulder, and shearing the metal of the enlarged shank substantially to the size of the reduced shank from the shoulder toward the head, as well as upsetting such sheared metal by forcing the shouldertoward a fixed shearing and upsetting zone, while re tarding the sheet from riding up the enlarged shank, such upset metal as well as the metal to be sheared and upset being forced downwardly toward the sheet and outwardly head at the other end and an intermediate enlarged shank forming a shoulder between the enlarged shank and the reduced shank in an aperture in the sheet material with the walls of the aperture closely engaging the enlarged shank at .the shoulder, shearing the metal of the enlarged shank substantially to the size of the reduced shank from the shoulder toward the head and upsetting the sheared metalv to cause a downward and outward flow of the material of the rivet toward the reduced shank side of the sheet to bulge the sheet material adjacent the aperture, enlarge the aperture and form a recess into which the rivet head is countersunk.

4. A method of securing a rivet in thin sheet metal which consists in providing a rivet having a head, a reduced shank ortion and an intermediate enlarged an tapered shank portion, forming a shoulder between the enlarged and reduced shank portions, placing the rivet in an aperture in the sheet material with the walls of the aperture closely embracing the enlarged shank portion adjacent the shoulder and the shoulder adjacent a shearing and upsetting zone, and applying pressure to the head of therivet to cause the material of the enlarged shank to be sheared to approximately the size of the reduced shank and to be upset outwardly and downwardly forming a recess in the sheet material and surroundingthe edges of the recess.

In witness whereof, I hereunto subscribe my name this 20th day of May A. D., 1927.

JOHN MCDONOUGH.

against the walls of the aperture and the reduced shank side of the sheet, whereby the friction of the downwardly moving shank, together with the outward flow of upset metal at and below the aperture will bulge the sheet adjacent the aperture, enlarge the opening and form a recess.

2. A method of securing a rivet in a thin sheet of material having an aperture, which consists in placing a rivet having a reduced shank at one end, a head at the other end, and an intermediate enlarged shank forming a shoulder between it and the reduced shank in the aperture in the sheet with the walls of the aperture closely embracing the enlarged shank and with the sheet closely adjacent the shoulder, shearing the metal of the enlarged shank substantially to the size of the reduced shank from the shoulder toward the head, and upsetting the sheared metal radially against the walls of the aperture while retarding the sheet from riding up the enlarged shank by forcing the shoulder toward a fixed shearing and upsetting zone to form a recess in the sheet material about the aperture for receiving the head of the rivet.

3. A method of securing a rivet in thin sheet material, which consists in placin a rivet having a reduced shank at one en a

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