US2186589A - Shoe stiffener blank and method of making the same - Google Patents

Description

Jan. 9, 1940. I sup. I O VELL 2,186,589

SHOE STIFFENER BLANK AND METHOD OF MAKING THE SAME Filed May 26, 1957 W655 A46. ran in 1 UNITED STATES Patented Jan. 9, 19.40

SHOE STIFFENER BLANK AND METHOD F t MAKING THE Stanley P. Lovell, Newton Center, ;Mass., assig nor. i a;

to Beckwith Manufacturing Company, Dover, I N. H., a corporation of Massachusetts Application May 26, 1937, serialo, 144,843 g 13 Claims. (01. 12;1 6 I .s

The present invention relates to shoestififener blanks and. method "ormaking the same,;and

-more particularly to that type of blank of the g pre-stiflened type which is cut or died out from "5 "a sheet of stiffened material, such, for example,

as a felt saturated with thermoplastic stiffening compound.

Heretofore theseblanks have been died out one 'at'a time by means of a hand die, prior 'atv '10 tempts to out these blanks with a multiple die having proved unsuccessful in commercial practice, due to the great length of cutting edge re- I quired by the conventional or standard'outline or configuration of the blank per square unit of \15 surface, and the consequent excessive pressure needed to force such a die through the material.

While these stiffener blanksmay be successfully died: out with the single unit die, this opera- 'tion is necessarily slow and "laborious: and in- 5 0 volves a great waste or material 'beca'use, due to the brittleness of thestiflening compound; one or more cracks would ordinarily be formed, extending outwardly from the line ofcut of the die into the uncutmaterial. To avoid such cracks '25 in blanks cut from adjacent portions of the sheet material it was necessary to spacethe cuttingdi'e a su fii cient distance to exclude them, resulting in the formation of a border or zone of stiffener material which was of substantial width-and err-- *tended entirely around the blanks. This border or zone was all waste and represented a very large proportion, sometimes" as high as 24%j,'c-i" area of the original sheet. a

. Itihas been attempted to avoidfthe formation of these cracks with the consequent high wastage 1 by dieing out the blanks with a multiple unit die when the sheetmaterial is soft and pliant from heat, as disclosed in my prior Patent No. l,962,--

603 of June 12, 1934, and while this enabled the j -40 blanks to be cut close to one anotherff-rom the sheet without forming cracks, thus eliminating a largepart of the waste. neverthelessdifiiculty was experiencedin keeping the cutting edges of the I 'die clean and free from the sticky, gummy, ma-

=45 terial with which the blank was stifiened and which interfered not only with the cutting operation'itself, but caused a seriousvariation in the size'of the blanks cut by the same size die. Another objection to the present method of 5 0 producing 'stifiener blanks bythe' use of-a single unit cutting die is the amount of hand labor required in handling the cut out blanks preparatory to the skiving operation. This operation is ordinarily performed in a machine having a 5115 magazine and automatic feed, the cut blanks bea ing stacked by hand in the magazine in a certain definite angular alignment. Where these bla-nks are cut by a single die, each blank has to 'be picked up by itself, brought to the proper "alignment and stacked preparatory to"being'5 transferredto the magazine of the skiving'maless wastagegand with the cut blanks aligned in pilesbr stacks ready for transfer totheskiving i or other machine for further manipulation.

To the above ends the present invention contemplatesthe forming 'of the stifiiener blanks with their side'edges straight for substantial portions-ofthe distance from the vamp line to the toe 'er'tip; instead of convexly curved, as is the present practice. By having the straight portions' of adjacent blanks coincide, a single cut-- ting edge-will serve for both blanks. As a result, thetotal length of the cutting edges of a mul- J tiple unitf die for cutting the new form ofblank willbe sufficiently reduced over one having a complete andindependent cutting'edge for the entireperimeter of each blank, as required with thesha'peof blank now in commercial use, that the pressure required per unit of area for operat- 30 ing such new die member will be much less and well within the practical limits.

Furthermore, when cutting a; sheetof material with a multiple die in a single operation, the

sheetwill be leftsuifficiently coherent to permit handling and stacking as a unit, yet with the stiifener blanks and the waste pieces sufficiently severed from the sheet to permit separation therefrom, and from one another, with a mini- "mum ofefiortL. L

Thus the operator, after stacking the sheets in vertical alignment, is enabled to remove the blanks a -pileor stack at a time, all similarly --ali gned, and transfer them to the magazine of the skiving machine or other Iinstrumentality. The handling-of each individual blank by itself is "thus avoided, "the blanks first being handled a in a'fhoriaontal group or layer in the original --sheet from which they are formed, and later in vertical aligned stacks consisting of one blankm fromreach of thesheets.

the accompanyingdrawing which illustrates one :embodimentof the present invention, Fig. l 1 H v is atop'plan view showing; infull line, the shape or contour-bf :the' stiffenerblank when formed .in

accordance with the present invention, those portions of the old blank, which have been altered or changed in the new construction, being shown in dotted line; Fig. 2 is a top plan view, on a reduced scale, of a portion of a sheet of material showing the arrangement or interlock of the improved stiffener blanks after they have been cut but before they have been separated from the sheet; and Fig. 3 is a perspective View of a corner portion of a vertical pile of cut sheets showing the manner in which the stacks" of aligned blanks and waste pieces are formed and how each stack may be separated from the pile of sheets and handled as a unit.

The new and improved stifiener blank consists of a generally segmental-shaped piece of felt or other suitable material saturated with a stiffener compound, such as one of the well known thermoplastics, comprising asphalt, resin, wax and other materials. The stiffening material for the blanks is usually produced by passing thefelt or other base material through a body of the hot stiffener compound, the excess being removed by pressure rolls, and the sheet or web allowed to cool and. stiffen. When cold and stiff the blank of the shape shown in Fig. 1 is died therefrom.

As heretofore formed, these blanks 4 had a rounded toe or tip portion 6 and a vamp line or I edge 8, shown in the drawing as straight, but sometimes either convex or concave. The side margins or edges were convexly curved from the corner portions Hi through the intermediate portions i2, shown in dotted line, to the toe portion 6.

As constructed in accordance with the present invention, this intermediate side portion, instead of being convexly curved as shown at I2, is formed in a straight line !4, shown in full lines. This permits the blanks to be cut from a sheet of stiifener material in the manner illustrated in Fig. 2, with the straight portions of the sides of adjacent reversely arranged blanks coinciding for substantial distances so that there is asingle line of severance between such blanks. With the blanks positioned in this manner on the sheet of stiffener material, the wastage, except at certain of the side margins, consists only of the small triangular pieces It left between the curved toe 6 of one blank, the straight vamp line of another,

and the curved corner portion ill of the third of three contiguous blanks.

A comparison of these small areas with the substantial amount of border or zone required to be left completely around the blank as heretofore formed and as illustrated in Fig. 3 of my prior patent, shows the great saving effected by the present invention. By actual measurement it has been found that this waste of vmaterial could be reduced from as high as twenty-two per cent of the original sheet to as low as four per cent, representing a net saving of eighteen per cent in the cost of the stifiener materiahwhich has little if any value as waste.

After the. box toe is out from .the sheet of stiifener material it is ordinarily skived, as at 18, along the vamp line 8 to form a thin or feather edge which will merge into the vamp and lining in the shoe without leaving any distinctive line or ridge showing on the top of the vamp. To facilitate the handling of the cut blanks and transfer them to the magazine of the automatic skiving machine in the proper. position or alignment, the sheets of material 20 as they come from the die press are piled vertically, one above the other, in the same angular position they occupied in the press so that vertical stacks or pilesof blanks will be formed with all the blanks in the same stack facing the same way, but different stacks facing different Ways. Such stacks are indicated in Fig. 3 of the drawing at 22, 24 and 26, and the waste material at 28. Ordinarily the sheets as they are discharged from the die press maintain their sheet formation becauseof the character of the material from which they are formed, so that they may be piled vertically, one above another, as shown.

From such a pile, the operator can remove the stacks of waste material and the blanks as units, and with little efiort. Thus, after removing the stack of waste material corresponding to that indicated at 28 in Fig. 3, which happens to be much larger than most of the waste stacks because of its location at the side edge of the pile of sheets, the operator grasps the stack of blanks indicated at 22, separates them fromthe rest of the sheets, and then transfers them, as a unit, to the magazine of the skiving machine, or to some intermediate point.

Similarly, the other stacks of waste material will be removed and the other stacks of blanks,

such as 24 and 26, transferred as units with such angular adjustment as maybe required to bring them into proper alignment in the magazine or other holder. r

In actual practice it has been found that a satisfactory size of multiple die and sheet may consist of thirty-six units or stiffener blanks and that apile of cut sheets sixty-five units high is a convenient size for handling.

The improved form of stiffener blank is incorporated in the shoe in exactly the same manner as with the blank now commonly used, being softened in an appropriate manner, as by heat if a thermoplastic stiffening compound is employed, or by a solvent if a solvent stifiening material is used, and then assembled'in the regular 4 o manner with the vamp, lining, and other shoe parts, and pulled over the last and lasted in place.

With the prior form of stiffener this operation invariably resulted in the formation of flutes or ears of surplus stiffener blank material adjacent to and on each side of the toe or tip. This surplus material, formed between the side jaws and the end jaw on the pulling over machine, would either be trimmed off and thrown away or forced down upon the bottom of the last. Its disposal, in one way or another, has always been a problem.

With the new form of stiffener blank, however, owing to the formation of this intermediateportion of the side edges of the blank in straight lines instead of 1 convex curves, this fullness or surplus of the box toe material disappears, and

the ears or flutes consist only of the upper leathmental shape having a convexly curved toe portion, convexly curving corner side portions adjacent the vamp line, and straight side portions intermediate the toe and the corner side portions.

2. A pre-stiifened blank for box toes comprising a piece of suitable material impregnated-with stifiening compound and being of generally segmental shape with a straight vamp line, a convexly curved toe portion, and substantial lengths of staight side portions oppositely inclined at the same angle to the vamp line.

3. The method of making stiffener blanks for box toes which consists in cutting a sheet of pre-stiiifened material in a single operation into a plurality of blanks having their toe portions curved and their side edges straight for a substantial length, adjacent blanks having their straight side edges contiguous.

4. The method of making stifiener blanks for box toes which consists in cutting a sheet of pie-stiffened material in a single operation into a plurality of blanks having their toe portions curved and their side edges straight for a substantial length, adjacent blanks having their straight edges contiguous and their vamp lines oppositely disposed.

5. The method of cutting stiffener blanks with curved toe portions from a sheet of pro-stiffened material which consists in severing the blanks along lines to form in asingle operation a plurality of parallel rows of blanks, the blanks of each row being oppositely'positioned, with respect to the Vamp line, from the blanks in adjacent rows, and the side edges of adjacent blanks in the adjacent rows being straight and contiguous for substantial lengths.

6. The method of cutting stiffener blanks with their side edges straightand contiguous for a substantial distance.

' '7. The method of making stiffener blanks for box toes which consists in successively and similarly cutting a multiplicity of blanks from sheets of material, superposing thecut sheets on one another while maintaining the sheets intact to form a pile with the corresponding parts in vertical alignment, and removing, as a unit, vertical stacks of aligned blanks. p

'8. The'method of making stiffener blanksfor box toes which consists insuccessively and similarly cutting a multiplicity of blanks and waste pieces from a series of sheets of stiffening material, stacking the cut sheets in vertical piles material into pluralities of the articles, handling posed and havingtheir straight edges contiguous.

11. A pre-stiffened blank for box toes comprising a piece of suitable material impregnated with stiffening compound and being of generally seg-.

vmental shape, with a straight vamp line, convexly curved corner portionsadjacent the vamp line, a convexly curved toe portion, and straight side portionsintermediate the curved toe and corner portions.

, .12. The method, of cutting stiffener blanks with curved toe portions from a sheet of prestiiiened material which consists'in severing-the blanks along lines to form two series of parallel 'ro-ws of blanks, the two series being at right angles to one another, theadjacent blanks in one series of rows being aligned with the top of one blank toward the vamp line of the adjacent blank, and adjacent blanks in the other series of rows having their vamp lines oppositely dis posedand their side edges straight and contiguous for a substantial distance, and the end portions of their vamp lines straight and contiguous to similar portions of the vamp lines of adjacent blanks inadjacent rows of such other series.

13. The method of cutting from a sheet of pie-stiffened material a stiffener blank' having a curved toe portion, a straight vamp iine and substantial lengths of straight side edges betweenthe toe portion and the vamp line, which consists in cutting the vamp line with its end portions coincident with the end portions of the

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