US2001032A - Manufacture of shoes having stiffened parts - Google Patents

Description

s. P.- LOVELL MANUFACTURE OF SHOES. HAVING STIFFENED PARTS 2 Sheets-Sheet 1 Filed Dec. 5, 1932 (aw/Z y s. P. LOVELL 2,@01,32

MANUFACTURE OF SHOES HAVING STIFFENED PARTS Filed Dec. 5, 1932 2 Sheets-Sheet 2 dwpkr iatented May 14, 1935 PATENT OFFICE MANUFACTURE OF SHOES HAVING STIFFENED PARTS Stanley P. Lovell, Newton, Mass., assignor to Arden Box Toe Company, Watertown,

Mass., a

corporation of Massachusetts Application December 5 1932, Serial No. 645,649

'1 Claims.

This invention relates to the manufacture of shoes having stiffened parts, for instance, a stiffened fore part and/or a stifiened back or rear part.- p

5 In making shoes having stiffened parts, it has heretofore been the practice to introduce under the upper leather of the shoe a stiffener blank which prior to the lasting operation was made limp and moldable by suitable treatment so as 10 to be conformable to the shape of the last. Such a blank was pre formed or pre-cut to'the desired shape and was skived accurately at its marginal portionsto render the inside of the shoe smooth and comfortable as well as to avoid unsightly ridges on the surface of the finished shoe. The stiifener blank usually consists of an integral fibrous sheet serving as a carrier for a stiffening agent of a colloidal nature. It is common practice to impregnate a fibrous sheet with such stiffening agent, to cut the stiffener blank from the impregnated sheet, and finally to skive the blank at its marginal portions to a feather edge. The blank inthis form reaches the shoe operator who renders it limp and moldable by the application of moderate heat .or by solvent action, depending upon the nature ofthe stiffening agent. The operator then assembles the moldable blank with the shoe upper and performs the lasting and pulling-over operations which impart to the blank its desired permanent shape.

In accordance with l the present invention, rather than depending upon the introduction of a, pre-formed stiflener blank into the shoe upper,

V the desired stifiening effect is realized by charging with stifi'ening agent at the desired zones the ,woven or other fabric which invariably is associated with the shoe upper as a doubler and/or lining. In accomplishing this result, I first treat,

the desired zone or locality of the doubler and/or lining with a solvent or gelatinizing liquid for the particular stiffening agent to beemployed and then associate with the liquid-treated'zone the stiffening agent under conditions resulting in a substantially complete solution or fusion of the agent, in consequence of which 'the agent flows into the treated zone, and, upon the evaporation of the solvent or gelatinizing liquid, functions to stiil'en such zone. Before such stiffening 'action has ensued, however, the liquid-treated zone toso gether with its associated dissolved or fused stifiening agent is. conformed to the shape of the last in the course of the usual shoe-making wo'perations. Byslmh practice, I may, for exam- 3 pie, eflect a 'stifi'ening of the toe porton of ,the

:55 shoe, the stiffening agent existing in the doubler and/or lining invariably forming part of the shoe upper assembly.

There are various ways of applying the principles of my invention. Let us assume, for example, that a shoe upper assembly is on the last 5 and is ready to be stiffened at its toe portion prior to conformation to the last. In accordance with my invention, the toe portion of the doubler and/or lining of the upper assembly is treated by immersion, spraying, or other suitable treatment with a suitable solvent or gelatinizing liquid for the stiffening agent, the fabric constituting the doubler and/or lining thereby becoming charged with solvent or'gelatinizing liquid. A film of the proper stiffening material is now laid on the wet doubler and/or lining and the upper assembly is then put through the pulling-over and bed-lasting operations. There are various combinations of solvent or gelatinizing liquid and films of stiffening material which might be used in the practice of my invention. For instance, the doubler-and/or lining can be treated with acetone, and films of cellulose acetate or cellulose nitrate may be used as the stiffening media. If desired, a film of gelatin may be used as the stiffening medium in which case, the doubler and/or lining may be treated with water or dilute acetic acid as the solvent or gelatinizing liquid. By using a solvent or gelatinizing liquid of the proper kind and by associating therewith a comparatively thin film of the stiffening medium, it is possible to sever the excess film lying outside of the solvent-affected film area before or after the pulling-over and bed-lasting operations have been completed. Indeed, a properly wet doubler and/or lining may be laid on a film or between two films of stifiening medium, the other parts of the shoe assembly brought together over the film, and a film blank corresponding to the wet zone of the doubler and/ or lining removed from the rest of the film. In other words, the solvent or gelatinizing liquid will etch or cut away from a sheet of film material, as if by knife or die action, the desired area of film material, for instance, an area corresponding to the toe portion of the upper. Rather than using a film for furnishing the stiffening medium to the wet doubler and/or lining, it is possible to apply solid powdered stiifening medium thereto. For instance, the wet area of the doubler and/or lining may be brought into contact with a mass of such powder or the powder may be sifted or projected 0 such area from aspray gun or atomizer. In su h case, however, there may be diiiiculty in realizing a uniform stifiening effects The use With the forsgonig end; other features and objects in view, my invention will now be described in conjunction with the accompanying drawings, wherein,

Figure l represcmts in plan view, before the operation, as shoe upper assembly, the portion oi the upper bemg lifted sway from the doubler and lining to show the solvent-treatd. Giza I Figure 2 is a, similar view with a film placed over the solvent-=treotod arcs.

Figine 3 illustmtes diagrammatically theblo'wing oi powdered stififening' medium over the solvent treotsd toe portion.

Figure 4 shows in perspective tho bottom of tho toe portion altos the pulling-over operation has ,,n completed, with the excess film being reincv 'ei at the margins of the shoe upper.-

' or gcletinlzod and tends to diffuse into assembly. v I fabric constitute ports of the shoe upper assembly and, after having supplied with the stifiemng medium in the up 1 and powdered iorrn respectively.

not previously been done.

Figures 5 and 6 are enlarged sectiom throu the stifiened ports of a shoe and illustrate the end results in the case of stiffening agent used mm Figure '7 is s side view of s shoe stifien'ed at its fore part in accordance with my invention, the fore part being shown in section.

While the drawings illustrate the stifiening of the fore port of a shoe in eccordance with my invention, it is of course possible to stiffen other ports, for instance, the buck or rear pert,und thus dispense with the use of a so-callcd counter. As shown in Figure l, the toe portion I of the doubler and/oz? lining of the shoeupper asseznbly may be thoroughly wet with a. solvent-.01 gelatinizing liquid, e. g., acetone,

medium. A film 2 of the stiffening medium may be laid upon the solvent-treated area. Should there be excess film materiel outlying the soivcnt trestcei treat, as shown in Figure 2, this excess may be readily removed. by bringing the upper 3; and the other parts of the upper assembly together, for! as hcreinbeiore observed, thev solvent soon creates a the boundary of the solvent treated area. the upper" has undergone tion has been conformed. to the shape of the last, as illustrated in Figm'c-i, it is also possible to remove readily the excess film material 4 beyond the marginal portion of the upper, if this has The excess film m'aterisl may be recovered and. reused in making new film moterial. Rather than using the stifiening agent in film form, powdered stiffening agent may, as illustrated in Flgu're'v3, be blown or otherwise projected on the solvent-treated area of the doubler and/or lining ofthe upper assembly. In any cvont, the solvent; ted ores receives stlflcnlng medium. in such "form that the medium is, substantially completely dissolved the fabric of the doubler and/or lining of the shoegupper that a. doubler and lining line of cut or severance at When been wet with solvent" ud.

propriate 10min ssscmbly is lasted and the solvent is permitted-to evaporatc,-the end result will be that illustrated lnFigures 5 and 6. Thus, as illustrated in both these figures, the stiifening medium will diffuse into the fabric layers and this nation's; be promoted by the pressure ap- I y when cellulose acetaste or cellulose nitraw is to serve as the stiffening v lasting and its toe por- 'selves advantageously to plied in shaping the ,upperussembly to the last. Such stiffening medium as remains as a. coating on the lining and doubler serves to-cement or bond together the successive the shoe upper, increasing the strength of the shoe upper structure at its stifiened portion. The stiffened portion is not appreciably thicker than the unstiffened therefore assumes the lines of the last more faithfully than is the case when. a. stiffener blank; of substantial thickness forms part of the shoe upper assembly us in prior art practice. Thus, as shown in'Figure '7, the stiffened toe portion 5 of the shoe is not visibly thicker than the unstifiened vamp portion and, accordingly, there is no tendency for '9. ridge to be raised in the shoe upper at the vamp line.

There are many advantages inherent in the practice of stiffening shoe parts in accordance with my invention. My invention makes possible the desired stiifening effect without the introductlon into the shoe upperoba blank which is apt to work loose in the shoe under the stresses of use. Moreover, the practice of my invention means that the expense incident to using additional fabric in making shoe stifiener blanks and in cutting, skiving, sorting and packing preformed blanks is, done away with. Shoe parts stiffened in accordance with my invention are capable of withstanding the stresses of use for the life of the for the stiffening medium is integral with, or part of, the shoe upper assembly.

In using films of stiffening medium in accordance with my invention, the thickness of the film may be coordinated with the degree of stiffness desired in the finished shoe. For instance, a womans dancing shoe need require a, film of, say, cellulose acetate of only about .003 inch thickness, whereas a woman's street shoe may require two such films next to the doubler. On the other hand, a man's dress shoe may-require the use of cellulose thickness sad 2. men's street or work shoe may require two such films next to the doubler. In any one of these cases, however, the film required is so thin that it is promptly dissolved or gelatinized substantially completely when brought in contact with a, doubler sud/or lining wet with the appropriate solvent.

While I have .herelnbelore described various preferred stilfening media, which lend themvin film form, for the purposes stiflening agents. Thus, practiced in connection with a. ing agent, it is possible to use a wide variety of stiffening agents, including not onlytbose hereinbcfore mentioned, but such other agents as resins, bitumen, which are soluble in various organic solvents, as

nevertheless, it is possible to use of my invention various other when my invention is well as water-soluble agents like caseimdextrm On the other hand,

gum arabimorthe like. when the stiffening agent is used in film form, such other film-forming stiffening pgents no caseim'slbumen, (e. g., blood albumen), gums,

layers constituting portions of the shoe and acetate film of .00! inch' formation and handling powdered stiffenhard waxes,.or tbelrequivolents,

(e. g., gum shellac), and artificial resins of the vinyl and rosy resins, might be employed. A caseincr albumen film may be acted upon by suitable alkaline aqueous solvent media, e. g., water, whereas gums-or artificial resins like we, fvinyl" and "rezylf' resins are soluble in various organic so! vents, such as the hydrocarbons. ,flcohols, others, or mixed solvents of this typo.

class of the so-colled layer of fabric, those steps which comprise wetting said fabric with 'a solvent for stiflening agent at the desired zone, associating solid stiffening agent with said wet zone in a form conduclve to a prompt and substantially complete solution of said stiifening agent, and conforming said zone to the shape of the last.

2. In a method of shoemaking which involves I lasting a shoe upper assembly having an internal layer of fabric, those steps which comprise wetting said fabric with a solvent for stiffening agent at the desired zone, associating stiflening agent with said wet zone in thin film form conducive to a prompt and substantially complete solution of said film, and conforming said zoneto the shape of the last.

3. In a method of shoemaking which involves lasting a shoe upper assembly having an internal layer' of fabric, those steps which compise wetting said fabric with a solvent for stiffening agent at the desired zone, associating stifl'ening agent with said wet zone in a powdered form conducive to a prompt'and substantially complete solution oLsaid stiffening agent,- and conforming said zone to the shape of the last.

. 4,111 a method of shoemaking which involves lasti ng a shoe upper assembly having an internal layer of fabric, those steps which comprise wetting the i'ore part of said fabric with a solvent for cellulose ester stiilening material, applying cellulose ester to said wet fore part in thin fllm form conducive to a prompt andsubstantially '3 complete solution of said firm, and conforming said fore part to the shape of the last.

5. In a method of shoemaking which involves lasting a shoe upper, assembly having an internal layer of fabric, those steps which comprise wetting tbefore part of said fabric with a solvent for cellulose ester stiflening material. applying cellulose ester to a face of said wet forepart in thin iilm form conducive to a prompt and substantially complete solution of said film, removing any fllm outlying said wet fore part after the solvent has acted upon the film in contact therewith and has madesaid, outlying film easily removable, and conforming the fore part to the shape of the last.

6. In a method of 'shoemaking which involves lasting a shoe upper assembly having an internal layer of fabric, those steps which comprise wetting the fore part of said fabric with a volatile. nitrocellulose solvent, applying nitrocellulose to said wet fore part in thin fllmform conducive to a prompt and substantially complete solution of lay: of fabric, those steps which comprise wetting the fore part of said fabricwith a volatile solvent for cellulose acetate, applying cellulose acetate to said wet fore part in thin film form conducive to a prompt and substantially com-' plete solution of said fllm, and conforming said fore part to the shape of the last.

STANLEY r. Lovma.

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