US2191869A - Staple - Google Patents

Description

Feb. 27, 1940. w. M. STONE 2,191,869

STAPLE Filed May 9, 1938 ffm/wins.

Patented Feb. 27, 1940 UNITED STATES PATENT vori-ICE STAPLE Warren M. Stone, Camden, N. J.

Application May 9, 1938, Serial No. 206,708 s claims. (c1. ca -4) The object of the invention is to provide a staple for securing together a plurality of layers of material or for securing one or more .layers of material to a penetrable body. A staple of this character comprises the usual crown and end legs, the latter being adapted to penetrate the elements intended to be secured together. In case the staple is used to secure together a plurality of layers of material, the crown of the applied staple overlies the top layer while the legs are bent inward toward each other under the bottom layer. In case the sta-ple isI used to secure one or more layers of material to a thick penetrable body, the crown will overlie the top layer and, without bending, penetrate the said body. The

staple may be made of various sizes and is adapted to a variety of specific applications.

The above specified characteristics of my improved staple are those which characterize conventional staples. The ordinary staple, however, cannot be relied upon to operate satisfactorily under all conditions of use and is not intended `or adapted for certain uses for which my improved staple is intended andl adapted. For example, When ordinary staples of small size are used for securing together certain materials resistant to penetration, the legs of the staple are apt to jam or clog, the ends of the legs adjacent to the crown being forced toward each other and the crown buckling downward, making the fastening insecure or ineffective. Again, when ordinary staples are used to fasten together a multiplicity of flexible sheetsV (e. g., paper) of easily penetrable material, the anvil of the stapling machine, which guides the free ends of the legs inward, will often cause the legs to be deflected before complete penetration, cutting or tearing the flexible material. Again the ordinary staple is ineffective to penetrate thin metal sheets, for which purpose a staple of special construction must be provided. My improved staple is open to none of the foregoing objections and has other special advantages which are hereinafter explained.

Several embodiments of the invention are shown in the accompanying drawing:

Fig. 1 is a perspective view of a staple made by bending a strip of metal of permissibly uniform thickness and width.

Fig. 2 is a perspective view of a staple which may be made from a block by fprging or -any other suitable metal-working operation.

Fig. 3 is a sectional elevational view of the staple of Fig. 2.

Fig. 4 is a plan view of half of the staple oi.'

Figs. 2 and 3 associated with the guide (shown in cross-section) of a stapling machine.

Fig. 5 is a view, similar to Fig. 3, of a modification.

Fig. 6 is a view, similar to Fig. 4, showing the application of the staple of Fig. 5 to the guide of a stapling machine.

The staple of Fig. 1 is formed by taking a strip of material of uniform width and thickness and of a width exceeding its thickness and bending its central portion at right angles to its end portions to form a relatively narrow crown a .and relatively wide legs b, b. i

The staple of Figs. 2 and 3 may be formed by forging or swaging a long block of material to form a relatively narrow crown c and relatively wide legs d, d.

In Figs. 1, 2 and 3 the transverse extension of the legs is beyond both sides of the crown. The staple of Fig. 5 is similar to that of Fig. 3 but differs therefrom in that the legs f. f are laterally offset from the crown e on one side only of the latter.

It will be understood that the staple of Fig. 1 may be similarly modified to produce a staple the legs of which are offset from one side only of the crown.

Any of the staples may be provided with legs tapering to sharp edges, as shown in Figs. 2, 3 and 5.

The form of the staple of Fig. 3 (and also of Fig. l) is such as to adapt it for use in a stapling machine provided with guides g whichembrace the legs of the staple on all four faces, and at all four corners, of each leg. It is therefore impossible to bend the legs during penetration, the governing basic principle being the same as that which enables a needle, embedded in a supporting layer of cork, to be held from deflection While being driven through a considerable thickness of metal. The same advantage inheres in the staple of Fig. 5, which is so shaped as to adapt it for use in a stapling machine provided with guides h which enclose the legs of the staple on all four sides and at three of the four corners.

It will thus be clear that a staple embodying my invention cannot jam or clog during penetration. No part of the leg can bend (if the staple is used for securing together a plurality of layers of material) until after such part has completed its penetration and therefore the crown cannot buckle. After the stapling operation is completed, the crown necessarily lies straight over the upper layer, the adjacent part of the leg extends at right angles to the crown, and the projectlng ends of the legs extend inwardly toward each other in parallelism with the crown.

Moreover, if the staple is used to secure together a number of sheets of paper, there cannot be any tearing, cutting or shredding of the paper, due to inward. deiiection of any part of a leg, be' fore it has completed penetration of all the sheets.

By making the crown height dimension the greater dimension in cross section and by onsetting the legs as described and shown with their smaller transverse dimensions parallel with the longitudinal extension of the crown, the stinness of the crown is enhanced and the strength of the staple as a whole is increased, while at the same time the weight of metal in the'staple may be safely less than that of the conventional staple of comparable size.

In the stapling machine, the guides g or h should be of internal dimensions slightly greater than the external dimensions of the legs, so as to provide a tolerance or clearance between the staple legsv and the walls of the guides.v 'I'his permits distortion, or lateral now with enlargement of cross section, of metal under the driving pressure. f

,It will be understood' that my invention may be embodied not only in staples which are formed separately before insertion in the stapling machine but also in staples which, in the stapling machine itself, are cut to length from a continuous strip of metal and bent to shape. 'I'hese alternative methods of forming staples are known in the art.

What I claim and desire to protect by Letters Patent is:

I. A staple comprising a crown and end legs, the crown being of greater thickness vertically than laterally and the legs being of greater thickness in the transverse direction of the staple than in a direction parallel to the longitudinal extension of the crown and of substantially greater thickness in the transverse direction of the staple than the lateral thickness of the crown.

2. A staple comprising a crown -and end legs,

all of similar and substantially equal oblong cross section, the greater thickness of the crown being in the direction of penetration and the greater thickness or the lees being e: riant longitudinal extension of the staple.

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3. A staple comprising 'a continuous strip of I metal the central portion and opposite end portions of which are all comparatively wide and thin. the greater cross-sectional dimensions of che end portions being et right angles ce the 'n greater cross-sectional dimension ofthe central portion, the metal strip being bent at the junction of the central portion and the end portions to laterally onset with respect to the sides of the -crow-n, thereby imparting maximum strength to the crown and enabling the legs to' be .guided ured' in either direction at right angles to its direction of extension, the legs being onset laterally from the adjacent ends of the crown, each leg from its junction with the crown downward being onset laterally from at least one side oi' the crown so as to adapt said legs, before and during penetration and until penetration is substantially completed, to be guided at all four sides and at not less than three corners.

5. A staple comprising a crown and end legs, the length of the crown between the legs being multiple times the thickness of the crown measured in either direction at right angles to its direction of extension, each end leg being onset laterally from both sides of the crown so as to adapt said legs, before and during penetration and until penetration is substantially completed, to be guided at all four sides and at all four corners.

6. A staple comprising a crown and end legs, all oi' oblong cross section, the greater thickness ,of the crown being in the direction of penetration and the greater thickness of the legs being at right angles to the longitudinal extension of the staple, the legs being onset laterally from the ends of the crown.

'l0 form a staple comprising a crown which is thicker f v in the direction of penetration and legs which are WARREN M. STONE.

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