US1990247A - Shank stiffener with attaching means - Google Patents

Description

Feb. 5, I935. s. M. NICKERSON 1,990,247

SHANK STIFFENER WITH ATTACHING MEANS Filed March 7, 1954 Patented Feb. 5, 1935 SHANK STIFFENER WITH ATTACHING' MEANS Stacy M. Nickerson, Newton, Mass Dplication"March 7, 1934, Serial No. 714,470

38 Claims. (01. 36-76) The present invention relates to the metal shank stifieners which are used in shoes for the purpose of maintaining the shape of the shank part of the shoe. It is particularly concerned with means for anchoring or attaching the stiffener to the innersole, for the purpose of holding it permanently in place; not. only during the manufacture of the shoe, but afterwards when the shoe. is on the wearers foot and subjected to flexure of various directions by the weight and movements of the wearer.

I-Ieretofore it has been the practice to secure such shank stiffeners by means either of separate tacks or of integral prongs cut from the substance of the stiffener itself driven through the innersole and clinched at the inner side of thelatter. Such tacks and prongs have always heretofore been made with sharp points and clinching of their pointed ends has been essential to prevent their withdrawal. But toclinch them requires that they be made longer than the thickness of thenormal innersole, and that the last on which the shoe is made be non-penetrable by the points of the prongs. Practically this has limited the use of permanent attaching means for shank stiffeners to shoes made on lasts which either have a continuous iron or steel plate on the bottom, or such a plate on the heel part. Where the heel part only of the last'is thus armored, the shank stiffener can be secured by clinched points only at the heel end thereof, which leaves the forward end free to rub and make squeaking noises when the shoe is worn, and to shift side- 'wise out of place.

The cost of equipping lasts with complete bottom plates of iron or steel is so great as to be practically prohibitive, particularly when styles are changed so frequently that the factories have to be equipped with newlasts at frequent intervals. Some shoe manufacturers have sought to lessen this expense by providing a bottom plate only at the heel part and setting an iron insert into the last bottom at the ball part thereof, which is the location of the forward end of the shank stiffener, so as to provide a clinching anvil for prongs or the like at such forward end. But this practice also is too expensive to be satisfactory. Consequently the more general usage at the present time is to stick the shank stiffeners to the innersole with cement only. This mode of attachment is effective only to retain the stiffener during the shoe making process, and is wholly ineffective to prevent it from shifting out of place throughout the wearing life of the shoe,

Another fatal objection to integral clincher prongs on shank stiffeners is the quality of the steel from which a large proportion of the shanks now in use are made. In order to provide adequate strength and resilience, these shank stiffeners are made of a hard steel composition; so hard that sharp prongs formed from their substance usually break when the attempt is madeto clinch them. When broken, the remnants of such prongs, due

to their inclined side edges, quickly work out of the innersole when the shoe is-being worn, and allow the stiffener to shift out of place. e Ihe invention herein consists in a shank stiffener having attaching means which are free from the objections above referred to, and are effective to secure the stiffenerin place without penetrating through the entire thickness of an innersole and without being clinched.

The drawing furnished herewith depicts the invention in a variety of equivalent-embodiments.

Fig. 1 shows a perspective View of my new shank stiffener equipped with integral anchor lugs at opposite sides adjacent to its two ends;

. Figs. 2 and 3 are detail sectional views on lines 2-2 and 3-3 respectively of Fig. 1;

Fig. 4 is an elevation of a shoe, with the shank part represented in section and showing the shank stiffener of Fig. 1 incorporated therein;

Figs. 5, 6 and 7 are views similar to Fig. 1 showing specifically different variants of the same invention;

Fig. 8 is a cross section on line 8.-8 of Fig. '7.

Like reference characters designate the same parts wherever they occur in all the figures.

or represents the shank stiffener body. This may be of any suitable form and dimensions, and is shown here as made from a strip of sheet steel approximately A in width, strengthened by being offset along its median line except at the ends, and being longitudinally curved conformably to the shank part of the shoe for which it is designed. The invention comprehends nothing newin these particulars, but may be embodied in shank stiffeners of widely varying character istics. The new step is embodied in the attach ing means, which in Figs. 1 and 2 consist of anchor lugs b, b' a'djacent to one side edge of the stiffener body, near the opposite ends thereof; and similar anchor lugs c, 0' near. the respectively opposite sides and ends of the body. These-lugs are formed by incising the shank body inwardly from its edge, on lines perpendicular to the edge, and bending the substance 9f the .Shank body between such cuts; up at right trated in Fig. 4. Shankstifieners equipped; with angles to the plane of the adjacent part of the body. By virtue of this construction, the lugs have parallel sidestheir end bounding edges are perpendicular to these sides, and they have the same thickness as the stock of which the shank leather-board, fiber, or other suitable material. But they are made of a height less than the thickness of the normal innersole stock so that, when the stiffener is appliedto' an innersole (1 (Fig.4) attached to the bottom of a last, the-- lugs will enter the substance of the innersole, but will not pass through it, substantially as illusthese attaching means are laid against the outer face of the innersole attached to a last bottom, as,usual, and the anchor lugs are driven into the innersole substance by hammer blows at each end of the stiffener. v, Y

' An adequately strong bond is created between the embedded lug andthe innersole material, notwithstanding that the lug is not clinched and does not pass all theway through the innersole. I attribute, the strength of this bond to the fact that the sides of 'the lugs are straight and paralleland their embedded corners are square, whereby the innersole material tends to hug and grip'the lug, rather than to crowd it outward. Another factor which I believe contributes to this effect is that the lugs have substantial width. Inthe example illustrated, their width is approximately one tenth of an inch; but it is to be understood that I do not limit my protection narrowly in this particular. In terms of proportional dimensions, the ratio of protruding height of the lugs here illustrated to their'width is approximately as six or seven to ten; and of thickness to width, as four to ten. But'whatever the correct explanation maybe, the demonstrated loose.

The anchor lugs aslshown in this drawing and heretofore described, have equal width at the extremity and base; (by base I mean the part of the lug which is connected with the body of the shank'stiffener). ;This is due to the parallelism of the cuts which sever the sides of the lug from the body of the stiffener; Its corners are. square, due to the fact that the cuts extend perpendicular to the edge of the body. However, it is within my contemplation to make the lugs slightly wider at the extremity than at the base, and make their corners slightly acute rather than square, in order to increase the strength of connection with the innersole by providing: space into which the innersole substance may'crow behind the entering edge of the lug.

Lugs such as those described above 'rnaybe variedin numbers and variously positioned; but preferably they are always near the opposite ends ,of the-stiffener where they leave the middle part free to flex under the weight of the wearer. Fig.

.lugs -b and c of Fig. 1; i. e., at respectively opposite sides and oppositeends of the stiffener.

Fig. 6 shows'a variation in which there are two such lugs, e'and 6, located respectively at the extreme ends of the stiffener body with their width' dimensions extending crosswise of the body,

instead of longitudinally as in the other forms illustrated. a

Fig. 7 shows a further variation in whichthere are lugs corresponding to c and c of Fig. 1 for embedding into the innersole, and other lugs f and f, of similar formation but oppositely turned, to be embedded in the outer sole as an additional anchorage against shifting of the stiffener in the completed shoe while being worn.

It will be understood that outturned lugs corresponding to f and i may be located at any desired points along the sides or ends of the stiffener body, and provided in any desired numbers,,in connection with upturned lugs arranged as shown in Figs. 5 and 6, or otherwise.

Such lugs may be formed in shank stiflfenersv of hard steel compositions, being severed and bent up before the stiffener bodies are hardened and tempered; That is, they are serviceable with sti-ffeners of those compositions which, in clincher forms, would causebreakage of theprongs when clinched. They are, equally serviceable inconnection with all types of lasts, ,wh'ether'the latter are entirely of wood, or, have iron bottoms; and as they cannot penetrate, to the inside of the shoe, they cause neither discomfort to the wearer nor destruction of the wearers stocking. v

What I claim and desire to secure by Letters Patent is: 1. A shank stiffener. of metal having an integral upturned anchor lug of a. length less than sufhcient topenetrate'throughia normal innersole, and of a width at its extremity substantially as great as its base width. 2. A shank stiffener of metal. having an integral upturned'anchor lug. of, alength less than sufiicient .to penetrate through a normal innersole, and of a width at its extremity substantially as great as its base width, the end bounding edge of said lug being substantially straight and making substantially equal angles with both side bounding edges, I

3. A shank stiffener of metalhaving an integral, upturned anchor lug of a length lessthan sufficient to penetrate through a normal innersole, and of a width at its extremity substantially as great asitsbasewidth, the outer cor ners of such lug being substantiallysquare. a 4. A shank stiffener ofstifi sheet metalhaving an integral lug formed asajpartiallysevered tongueprojecting substantially at right angles to the portion of the stifiener body contiguous to its base and having substantially parallel side edges substantially perpendiculari-to said con tiguous part of the .body.

5. A shank stiffener of tempered. steel having an integral upturned anchor lug of which both outer corners are no greater than a right angle and the height is less than the thickness of a normal innersole, while the thickness is small enough to permit penetration into the substance of an innersole. 1 1 r Y 6. A shank stiffener consisting of a body formed from sheet steel, hardened and tempered,

and having upstanding anchor lugs at opposite ly square end edge at substantially right angles -with such'sides; said lugs having substantial width and being sufiiciently thin to penetrate innersole material; and the stiffener having similar lugs projecting oppositely to the lugs first described adapted to be embedded in the substance of the outer sole of the shoe when the lugs first described are embedded in the innersole of the same shoe.

'7. A shank stiffener consisting of a sheet steel body having integral anchor lugs partially severed from its substance and turned respectively upward and downward, adapted to be embedded in the material of the innersole and outer sole respectively of a shoe; said lugs having substantial width, with substantially square corners, and being of less height than the thickness of the innersole and outer sole respectively in which they are designed to be embedded.

8. A'shank stiffener consisting of a sheet steel body having integral anchor lugs partially sevouter sole in which they are designed to be em- 10 bedded. STACY M. NICKERSON.

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