Patented Oct. 19, 1937 UNITED, STATES RIVET Francis L. Sheane, Shelton, Conn., assignor to Shelton Tack Company, Shelton, Conn., a corporation of Connecticut Application December 18, 1935, Serial No. 54,984
3 Claims This invention relates to rivets. More particularly the present invention relates to a rivet provided with a downwardly converging head and with means for gripping the mate- 5 rial with which'it becomes intimately associated when in use. i w
A primary object of the invention is to provide a rivet that will allow distribution of stresses onthe material intimately associated therewith over substantially the entire area comprehended by the under-surface of the rivet head rather than merely to the portion of the material immediately adjacent the rivetshank; also, to provide means for exerting a drawing force on the material intimately associated with the under-surface of the rivet head, inward toward the rivet shank. to
counteract the tendencyotherwise inherent in. such downwardly converging head of exerting compressive forces outwardly on the material therewith associated.
Embodiments of the present invention include a. rivet having gripping means concentrically arranged on the under-surface of its downwardly converging head.
In preferred forms such gripping means takes,
the shape of a plurality of annular ridges concentrically arranged on the under-surface of the rivet head from the outer diameter of the rivet shank outward to the periphery of the rivet head,
each set of annular ridges, comprising those annular ridges which are mutually adjacent, in- ,cludin'g a groove between component annular ridges having its bottom closer to the top of the rivet head than are the free ends of the compo- 5 nent ridges.
advantageouslyemployed as equivalents of the concentric ridges- Further features and objects of this invention 40 are clearly set forth in the following detailed description together with the accompanying drawing, in which: I
- Fig. 1 is a view partly in side elevation and partly in vertical section of a. preferred embodiment of the present. invention.
Fig. 2 is a bottom plan view of the embodiment Various other formations having similar gripping characteristics may, however, be
I Fig. 5 illustrates in side elevation anothe'r'embodiment of this invention.
Fig. 6 is a bottom plan view of the rivet shown in Fig. 5.
Referring to the drawing and particularly to Figs. 1 and 2;at I0 is illustrated a rivet. including one form of gripping means contemplated by this invention.
The rivet I0 is preferably of unitary structure and may be produced by any of, the usual methods common in the rivet making art.
As component parts of the rivet-I0, are the shank II and the head I2, the shank II preferably including a recess I3 inits free extremity to facilitate spread of the material of the shank during the actual riveting operations, and the head I! having a downwardly converging undersurface.
On the under-surface of, and desirably integral with the head I2, is provided gripping means. Such means preferably take the form of a plurality of annular ridges I4 concentrically arranged between the outer periphery of the shank -I I. and the periphery of the head I 2, and desirably being of substantially V shape to present the biting edges Ha. It will be noted that each set of concentric ridges I4, comprising those concentric ridges which are-mutually adjacent, include between component ridges a groove for receiving the material to be held, the bottom of the groove being closer to the top of the rivet head than are the free ends of the stated component concentric ridges.
When the rivet is in its riveted holding position, the ridges I4 bite into the material with which they become intimately associated, and, when such material is subjected to external stresses, serve to distribute the effects of same over substantially the eritire' area comprehended by the undersurface of the rivet head I 2 rather than to merely that limited area immediately adjacent the rivet shank II. Thereby, undue stresses at such shank adjacent area are pre vented. I
In Figs. 3 and 4 is shown a specialized appli- 45 cation of the present invention wherein rivets such as l0, having downwardly converging heads I2,:preferably of a. general conical configuration, are utilized to fasten brake lining, such as l5, to a brake band, as at l6.
The assembly, represented by the brake lining I5 and the brake band It, is provided with rivet receiving holes II conflgurated to form a sub 'stahtially frusto-conical seat Ila, for receiving and positioning the under-surface of the heads I2 of rivets II in the material of the lining I 5, the shanks I of the rivets passing through the opening I! in the band l6 and being spread into holding position as at ll'a.
positioned, the downwardly converging rivet head l2, exerts a force upon the material of the lining IS in a direction substantially normal to the converging under-surface of the rivet head. Were this under-surface relatively smooth, as is commonly the case, there would arise undesirable stresses in the lining material l5, and, if such material were brittle to any degree, as in the case of molded linings, such stresses would tend to split off sections of such material under normal brake operation.
Thegripping means forming the substance of the invention, and illustrated at II in the form of a plurality of annular concentric ridges similar to those shown in Figs. 1 and 2, counteract the aforesaid splitting forces by biting into the material of the seat l la and tending to draw the lining in toward the rivet shank ll when the brake assembly is under operative stresses.
Another embodiment of gripping means is shown at 2|, Figs. 5 and 6, on the under-surface of the head of therivet 20, and is anotherexample of the various gripping formations comprehended by the present invention. The formations 2| include a plurality of arcuate projections arranged in substantially staggered rela-.
tionship on the area of the under-surface of therivet head 22.
Whereas, I have described my inventionwith reference to specific forms thereof, it will be understood that many changes and modifications may be made without departing from the spirit of the invention.
I claim:
1. A rivet including a head and a shank, the
the converging surface of said head throughout the area thereof between the outer periphery of the shank and the periphery of the head, each set of gripping formations, which comprises those gripping formations mutually adjacent radially of the said converging surface, including between component gripping formations a groove whosebottom lies closer to the top of the said head than do the free ends of the said component gripping formations.
2. A rivet including a head and a shank, the bottom surface of said head converging toward said shank, and annular ridges concentrically arranged on the converging surface of said head throughout the area thereof between the outer periphery of the shank andthe periphery of the head, each set of annular ridges, comprising those annular ridges which are mutually adjacent, including between component annular ridges a groove whose bottom lies closer to the top of the said head than do the free ends of the said component annular ridges.
3. A rivet including a head and a shank, the bottom surface of said head converging toward said shank, and annular ridges concentrically arranged on the converging surface of said head throughout the area thereof between the outer periphery of the shank and the periphery of the head, each set of annular ridges, comprising those annular ridges which are mutually adjacent, including between component annular ridges a groove whose bottom lies closer to the top of the said head than do the free ends of the said component. annular ridges, said annular ridges being interrupted at intervals throughout their annular extensiom FRANCIS L. SHEAlTE.