US2983179A - Sheet metal screw - Google Patents

Description

May 9, 1961 D. A. WEINSTEIN SHEET METAL SCREW Filed April 25, 1959 H lk IN V EN TOR.

DONALD A. WEINSTEIN EEQ United States Patent SHEET METAL SCREW Donald Allen Weinstein, Toledo, Ohio, assignor to Prestole Corporation, Toledo, Ohio, a corporation of Michigan Filed Apr. 23, 1959, Ser. No. 808,341

1 Claim. (Cl. 85-1) This invention relates to sheet metal fasteners and an object is to produce a simple and efficient nut-receiving fastener from sheet metal and a method of making same.

Another object is to produce a fastener from a single strip of sheet metal folded to form a multi-ply structure, the edge portions of which are formed with threads such that they cooperate threadedly to engage a nut screwed thereon.

A further object is to produce a novel method of making such fastener from sheet metal. 7

Other objects and advantages of the invention will hereinafter appear and, for purpose of illustration but not of limitation, an embodiment of the invention is shown on the accompanying drawings in which:

Figure 1 is a perspective view of the sheet metal screw;

Figure 2 is an end elevation of the sheet metal screw shown in Figure 1;

Figure 3 is a top plan view of the screw;

Figure 4 is a longitudinal sectional view on the line 44 of Figure 3; and

Figure 5 is a diagrammatic view showing the means for stamping the threads on the edge portions of the screw in the manufacture thereof.

The illustrated embodiment of the invention comprises a unitary screw formed from flat spring metal and, as shown, comprises a fiat body or head generally rectangular in shape and from a narrower end, a pair of laterally spaced parallel slits 11 are formed to provide an elongate tongue, which is formed into a post-like member P. As shown the tongue is first bent at substantially right angles to the head 10 to provide a ply 12. The tongue is then folded upon itself intermediate its ends to provide another ply or folded back portion 13 which is pressed intimately into face to face contact so that throughout the face of each ply is in intimate contact. The terminal portion 14 of the tongue is bent at substantially right angles to the post P and then is disposed'with in the plane of the head 10.

It will be understood that the side edges of the ply portions 12 and 13 are flush with each other and in these edges are formed teeth 15. These teeth. are such that a nut N may be screwed thereon. Thusthe thread sections may be regarded as being of mating character on opposite sides and forming sections of a helical thread.

Figure 5 diagrammatically shows the method of stamp,-

' ing the thread sections on the edge portions of the post P.

As shown there are two complementary dies D. Initially these dies might be in one piece and a continuous helical ice screw thread formed in the bore thereof. Thereafter by cutting the die in two to form two sections, it will be manifest that the screw threads of the two sections are complementary. The sections are disposed on opposite sides of the post P with the edge portions thereof exposed to the threaded portions of the die parts. Thereafter the two die parts D are pressed toward each other or in the direction of the arrows, shown in Figure 5, to stamp the threads in the flush edges of the plies 12 and 13. To prevent twisting or deformation of the post P a pair of rams R may back up or bear against the sides of the post P during the thread pressing step. Subsequently the rams R are withdrawn and thereafter the die parts D are withdrawn leaving-the post P with the pressed threads on opposite edge portions suitable for the reception of a nut N.

The above described sheet metal screw can be produced at a modest cost and may be embodied in a wide variety of forms, one important use being for clips for ornamental moldings, for attaching the clip to a supporting panel. It will be observed that the two plies 12 and 13 are free of welds or rivets and are merely pressed together in intimate face to face contact. The stamping of the threads on the edge portions of the fastener not only produces an excellent screw-like post for not reception but can be performed quickly and economically on a quantity production basis. By employing the double ply structure relatively light gauge sheet metal maybe employed and still have adequate strength. Instead of a two ply structure, three or more plies maybe employed where occasion demands.

Numerous changes in details of construction, arrangement, and choice of materials may be effected without departing from the spirit of the invention especially as defined in the appended claim.

What I claim is:

A sheet metal fastener comprising a flat body, a flat relatively narrow tongue struck from the body and integral with the body at one end and extending at approximately right angles thereto, said tongue being doubled upon itself with the two portions of equal length and pressed into intimate face to face engagement with the edges flush with each other, threads on the opposite edges of each of the two portions and cooperating with each other to enable a nut or the like to be threadedly applied thereto, and a terminal portion on said doubled back portion extending at substantially right angles to said doubled-back portion to a position flush with the body portion within the space created by striking the tongue from the body. 1

References Cited in the file of this patent UNITED STATES PATENTS Kleifman June 19, 1923'

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