US680991A - Screw-nut. - Google Patents

Description

ENCE.

ATENT :WILLIAM n. CROSBY, OF BUFFALO, NEW YORK', ASSICNOR ToV THE CROSBY COMPANY, OE SAME PLACE.

'SCREW-NUT..

lSPECIFIGA'L101`1'tfol'flltgpart Of Letters Patent N0. 680,991, dated. August'20, 1901.

Application led May I 1901. Serial No. 60,324. (No model.)

`To. all whom t may concern: I

Be it known thatl, WILLIAM H. CROSBY, a citizen of the United States, residing at Buffalo, in the county of Erie and State of New .Yorin have invented a new and useful Improvement in `Screw-Nuts, of which the following is a Specification.

This invention relates generally to screwnuts, and more particularly to the class of nuts `which are commonly known as cap-nuts and which are provided at their crown or outer end with an inwardly-turned lip adapted toA i overlap theend of a tube or other member or a shoulder of the member to which the nut is applied for forming a neat finish. My in vention has more especial reference to a cap-- nut stamped from sheet metal and to a method of making the same. Heretofore it has been attempted to make such nuts partly of sheet metal by stamping a cupshaped blank or crown with a cap-flange at its small end and l F ahexagonal socketat its large end and driving an ordinary screw-nut into this socket.

` Cap -nuts comprising .two pieces have also l so` r pieces and which is free from the Objections above stated.

been constructed by stamping the body of the nut from a blank and driving a sheet-metal .r g `cap or iianged collar upon the reduced cylinx "drical portion of the stamped-nut body. Both Iof these constructions are comparatively eX- pensive, and the 'two parts of the nut are The object of my invention is the produc cheaper than nuts machined from a solid bar of metal and those composed of a number of In the accompanying drawings, Figure l is `a perspective view of the. fiat.V blank from `,which my improved nut is stamped. Figs.

2, 3, and 4. are sectional elevations of different sets of dies which are employed for forming the nut, showing the shape of the blank at differentstages of the stamping operation.

Fig. 5 is a longitudinal central section of the completed nut. Fig. 6 is a bottom plan view f of the same.

Like letters of reference refer to like parts in the several figures.

portion of my improved cap-nut, havinga projecting hexagonal rim a', and a2 is its crown portion, having an inwardly-turned lip or flange a3, which forms the cap of the nnt. The nut is stamped in a single piece from a flat blank of sheet metal, such as sheet-steel. The base portion o. of the nut, in which the greater portion of its screw-thread is cut, is thicker than the original thickness of the blank, while the crown portion a2 may be thinner than the original thickness of the blank, as shown.

In making my improvedcap-nut a flat sheet-metal plate or blank B of circular form is first cut or punched, and this blank is stamped between suitable male and female dies C C to approximately the shape of a tapering cup, with a convex bottom and aproing the deeper set. A circular hole somewhat smaller than the bore or internal diameter of the screw-threaded portion of the finished nut is next punched centrally in the bottom of the cup-shaped blank by suitable dies D D', as shown in Fig'. 3. The rim of the perforated blank is then trimmed OE to reduce its diameter, and the blank is further stamped be tween dies E E of substantially the shape of `the preceding dies, but Shallower and larger in diameter than the same, as shown in Fig. 4. The bottom of the female die E is substantially horizontal, and the lower portion of the maleQ die E is stepped to formupper and lower annular shoulders e c. of the male die between these shoulders is somewhat larger in diameter than the corresponding portion of the male die D of the preceding set, and the portion e3 of the male die E below its lower shoulder e is somewhat smaller in diameter than the corresponding portion of the male die D. The upper portion of the male die is surrounded by acollar or stripper E2, which descends with the same and which has its under side arranged flush The portion e2V IOO inwardly to form the cap-Harige as `of the nut,

and the blank is at vthe same time upset or compressed lengthwise to the form shown in" Fig. 4, the same being reduced in height and enlarged in diameter, its walls thickened, andy themetal condensed. A The collar E2, descending upon the rim portion of the blank, aids in upsetting the blank and confines the metal in the upper portion of the female die. The blank may be gradually upset to the form shown in Fig. 5 by two or more sets of dies made successively shallower and wider. A screw-thread is next cut in the Vring-shaped nut-blank so formed, and the rim of the blank is finally punched by suitable dies to the hexagonal form shown in Fig. 6, or, if desired, the saine may be left circular or flattened only at opposite points ory otherwise suitably formed to receive'a wrench or other toolfor turning the nut. Before threading the nut the portion of its bore'adjacent to its cap-flange a may be undercut by a suitable tool, las shown in Fig. 5.

By stamping the nut asabove described its base portion, in which the greater part of the screw-thread is cut and which is subjected to the greatest strain, is thickened beyond the original thickness of the flat blank, providing a suicient amount of stock in that part of the nut for cutting the screw-thread without sacrificing the strength of the nut. A nut practically as strong and of as sightly dimensions as a nut machined from a solid bar is thus produced from a blank of mini- ,mum thickness and at a much smaller cost than that of a machined nut or one composed of two stamped members or partly of a machined member and partly of a stamped member, and as the improved nut is stamped of an integral piece it has none of the objections of a two-piece nut.

While I have herein shown and described my improvement as applied to a cap-nut, the feature of providing an integral sheetmetal nut with a thickened base portion is equally applicable to nuts un provided with a cap-flange. p

I claim as my inventionl. A screw-nut pressed from an integral blank of sheet metal and having its screwthreaded base portion upset for thickening the same, substantially as set forth.

2. Ascrew-nut pressed from an integral blank of sheet metal and provided at its crown with an inwardly-turned cap-lip and having its screw-threaded base portion thickened by upsetting the same between suitable dies, substantially as set forth.

3. A screw-nut pressed from an integral blank of sheet metal and provided at its crown with an inwardly-turned cap-lip, the capped crown portion of the nut being stamped of lesslthickness and its base portion upset to a greater thickness than that of the blank, substantially as se't forth.

4. A nut-blank pressed from an integral plate of sheet metal, and consisting of a rind provided at one end with an inwardly-turne cap-lip and at its opposite end with a projecting rim and having the portion thereof adjacent to said rim upset to a greater thickness than that of the plate from which the nut-blank is pressed, substantially as set forth. Y 5. The herein-described method of making an integral sheet-metal nut-blank, which consists in stam pin ga flat plate or blank approxi` mately to the form of a cup, then forming an opening in the bottom of the cup, and. then thickening the wall of the perforated cup by upsetting the same between suitably-shaped dies, substantially as set forth.-

6. The herein-'described method of making an integral, sheet-metal cap-nut, which consists instamping a flat blank approximately to the form of a cup,- then forming in the bottom of the cup an opening of smaller diameter than the bore of the completed nut,

and finally thickening the Wall 'of the per-v forated cup by upsetting the same between suitable dies and at the same time turning form the cap-ange of the nut, substantial] asset forth.

Witness myhand this 8th day of May, 1901.

WILLIAM H. CROSBY.

Witnesses:

A. D. DANA, CARL F. GEYER.

`the perforated end of the cup inwardly to

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