US2154306A - Staple strip and method of producing the same - Google Patents

Description

April 11, 1939. c. B. GOODSTEIN STAPLE STRIP AND METHOD OF PRODUCING THE SAME Filed March 18, 1957 INVENTOR E- IHRLEE E1. E0013 5mm ATTORNEY Patented Apr. 11, 1939 PATENT OFFICE STAPLE STRIP AND METHOD OF PRO- DUCING THE SAME Charles B. Goodstein, Brooklyn, N. Y.

Application March 18,

2 Claims.

The present invention relatesto an improved staple strip and method of producing the same,

and has for an object to provide a staple strip in which the staples are of uniform and accurate shape and size, in which better penetration of the staple legs through the material to be stapled is obtained, and through which better clinching of the staple is produced, the clinched staple being relatively flatter than the usual type of staple and holding the material with greater strength and reliability.

The invention relates especially to staples of U-shape. Heretofore it has been extremely difllcult to obtain such U -shape staples in which the staple legs were at a perfect right angle to the intermediate portion or crwn,'and this has been due to the hardness of the stapling wire, which is essential for proper penetration. As a consequence of the hardness of the material the wire m has a certain amount of springiness or temper,

so that the staple when bent to U-shape would tend to spring outwardly.

In the present invention it is proposed to take advantage of this condition and at the same time u produce a staple in which the legs are at a perfect right angle to the crown, and in which the legs are of tapered cross-section from end to end, the tapering of the legs lending itself to several advantageous results. For example, they will 3 penetrate the material with greater ease, the staple legs will bend upon the anvil in the form of a curve, as distinguished from staple legs of uniform cross-section which tend to bend angularly, and the staple may be used in a machine in which the staple guide passage is designed for the particular shape of the staple, and will not permit of the use in such machine of a staple of the usual type having legs of uniform cross-section.

With the above and other objects in view, the staples according to an exemplary embodiment of the invention, and the method of forming the same, are illustrated in the accompanying drawing, and the invention will be hereinafter more fully described with reference thereto, and the invention will be finally pointed out in the claims.

In the drawing: I

' Fig. 1 is a perspective view of a series of staple forming members bent to approximate U-shape with the legs slightly sprung outwardly, the staple pieces being coagulated by means of a suitable adhesive prior to the next step in the method of forming the staple.

Fig. 2 is a perspective view of a staple strip, according to the invention.

1937, Serial No. 131,643

Fig. 3 shows the manner of forming the staples by grinding the outer surfaces of the staple legs into planes at right angles to the crown, the staple legs being thereby given a tapered shape from end to end.

Fig. 4 is a sectional view showing the staple strip engaged in a machine especially designed to receive it.

Fig. 5 is a sectional view showing the clinched staple in relation to the material and the clinching anvil.

Referring to the drawing, the staple wire employed in the formation of the staple may be of circular, rectangular, or other suitable crosssection, as desired. As shown in Fig. 1 it is bent into the form of a substantially U-shape staple having a crown portion l0 and leg portions II--- II, which are slightly sprung outwardly due to the natural tendency of the hard staple forming wire to assume this shape. The staple forming pieces are coagulated by means of a suitable adhesive, or by any suitable means whereby they are arranged and held in a strip. As shown in Fig. 3 this strip is engaged upon a mandrel l2 having a cross-sectional shape corresponding to the inner outline of the staple strip, that is, the upper surface is horizontal and the side surfaces diverge downwardly. The strip mounted upon the mandrel I2 is fed into relation to grinding rollers i3-I3 which grind the outer surfaces of the legs so that they are in right angular relation to the crown. It will be seen that this right angular relation does not depend upon the bending of the staple, but is produced independently by the grinding operation, so that the outer faces are of extreme accuracy and uniformity.

In Fig. 4 I have illustrated the type of staple guide rail which may be employed in the machine using the staple strip of the invention, the guide rail l4 having downwardly diverging side surfaces which with the inner surfaces of the channel l5 provide tapered guideways for the legs. It will be seen that while this type of machine will only receive this particular type of staple, the same staples may nevertheless be used if desired with the ordinary type of machine adapted to receive staples having straight legs.

In Fig. 5 I have illustrated the manner in which the staple is clinched, the legs being bent as a continuous arc by the anvil I6 so that they are free from any exposed points or angular formations. By varying the curve of the anvil the legs may be bent in a smaller or larger circle as desired. The curving of the legs is due to the fact that the staple leg first bends on its weakest portion, which is of course the end first engaging the anvil, and will continue to do so until a perfect circle is completed. In the bending of the ordinary type of straight staple leg the wire as it projects through the material will, depending upon its rigidity, first bend in a sharp angle on a radius further back from the point of the staple leg and as the clinching operation is continued this operation will be repeated, so that the clinch is in the form of a series of angular bends.

I have illustrated and described a preferred and satisfactory embodiment of the invention, but it will be obvious that changes may bemade therein, within the spirit and scope thereof, as defined in the appended claims.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. A strip of adhesively connected U-shape wire staples each having a crown and bendable leg portions, said crownconsisting of a section of wire of uniform cross-section having the same surface characteristics at its inner and outer surfaces as the wire, each of the leg portions diverging downwardly at their inner surfaces with.

the same surface characteristics of .said wire and being continnations oi the inner surface of said crown, and their outer surfaces being in parallel relation to each other and in right angular relation to said crown whereby the staple legs are of tapered cross section, said outer surfaces belng flat and having different surface characteristics from saidwire distinguished by grinder produced surfacing and the outer surfaces of the staple leg portions in the strip being in a continuous plane at each side.

2. The method of forming a strip of adhesively connected staples from wire of uniform crosssection which consists in bending the wire into substantially U-shape with the legs diverging downwardly and grinding the outer faces of said legs into parallel relation with each other and into right angular relation with. the crown, whereby staple legs of tapered cross-section are produced and the outer surfaces of the legs are in continuous planes at each side.

CHARLES B. GOODSTEIN.

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