Патент USA US2406738код для вставки
Sept. 3, 1946. J. J. BROPHY 2,406,738 APPARATUS FOB USE IN STIFFENING UPPERS OF SHOES ' Original Fliled Nov. 22, 1944 0 H, xx)?" 1 67 4/ 2 Sheets-Sheet 1 SePt- 3, 1945' J. J. BROPHY 2,406,738. ‘APPARATUS FOR USE IN STIFFENING UPPERS OF SHOES Original Filed Nov. 22, 1944 . ' 7616'? F196: 37 a9 2 Sheets-Sheet 2 3/ 1 ‘f9 7’ "/I _______ iii ~ \ I", I l .......... -. “7 Patented Sept. 3, 1946 2,406,738 ‘UNITED STATES PATENT ‘OFFICE amass APPARATUS FOR USE IN STIFFENING UPPEBS 0F SHOES John J. Brophy,‘ Salem, Mass., assignor to'United Shoe Machinery Corporation, Flemington, N. .L, a corporation of New Jersey Original application November 22, 1944, Serial No. 564,605. Divided and this application August 10, 1945, Serial No. 610,110 7 Claims. (Cl. 12-—51) 1 This invention relates to stiffening selected portions of the uppers of shoes and is herein set forth in connection with stiffening the toe portions and the rear portions of uppers. It is common to provide a toe stiffener blank, usually one having a fabric base impregnated with a stiffening substance, which can be soft ened and rendered limp by treatment with a sol vent or with heat; to incorporate the softened blank in an assembled upper; and then to con 10 form the upper with the softened blank to a‘ last, the blank becoming hard and resilient upon evaporation of the solvent or upon dissipation of caused to run together so that, when the shellac hardens, a stiffened portion of the upper results. Shellac is not a satisfactory material for use in stiffening portions of the uppers of shoes; and subjecting the selected portion of the upper to radiant heat for approximately an hour at a tem perature between 210° and 250° F., as is necessary in the patented process, is extremely injurious to all but a very few kinds of‘ leather. Consequently no one, so far as I am aware, has ever made use of the Schwartz process, said patent never hav ing advanced at all the art of shoemaking. According to the present invention there is ‘ incorporated in a selected portion of the upper, There are certain disadvantages involved in 15 in cold, dry, non—fused form, a resinous material the use of stiifener blanks of the general type which can be caused to coalesce when subjected the heat. outlined above. They can be most conveniently incorporated in the assembled uppers, and are to the heating e?ect of a high-frequency ?eld. The resinous material, while cold and dry, is con usually so incorporated, just prior to the pull formed with the upper of a shoe to a last and ing-over operation, a special solvent-applying or 20 subsequently is subjected to the heating effects heat-applying apparatus being provided for of a high-frequency ?eld. This material pro rendering them temporarily limp. They become duces a tough, strong stiffener. By making use of a high-frequency ?eld the heat is applied di hard and resilient as soon as the solvent has evaporated or the heat dissipated; but it is dif rectly to the stiffening material. The heat need ficult to maintain them limp, and hence in con 25 be applied for only a very short interval; there is no danger of injuring the upper of the shoe dition for being conformed to the last, for just the right time, and then to have them become such as is present when radiant heat is used, and a resinous material having a comparatively high hard soon afterward so that the last may be melting point can be employed. removed from the upper. These and other dis advantages present very considerable di?iculties 30 Preferably the electrodes of the high-frequency apparatus are ?exible members mounted in a to the use of such blanks as counter stifieners ?exible presser which is pressed against the se so that, although toe stiffeners of the general lected portion of the upper. In this manner not type under discussion are widely used, no shoe only is a stray ?eld from the electrodes made use manufacturer, so far as I am aware, uses them 35 of to heat the stiifening material but the stiff as counter sti?’eners. The patent to Schwartz No. 1,215,875 of Feb ener blank is caused, by the action of the presser, to conform very accurately to the contour of the ruary 13, 1917 discloses a method intended to avoid the disadvantages involved in the use of last beneath it, and the upper, stiffener and lin ing are ?rmly bonded together. , stiffener blanks which are given a preliminary treatment to ‘render them soft and limp. before 40 The invention comprises a method, an appa ratus for use in carrying out a step of the meth they are conformed to the last. This patent dis od, and an article which is used in the method. closes a method which comprises the use of a Referring to the accompanying drawings, stiffener blank carrying shellac in powdered or Fig. 1 is a plan of a toe stiffener blank accord broken form, whereby the blank is limp when cold and dry. Such a stiffener blank is incorpo 45 ing to the present invention; rated in the assembled upper of a shoe and con . Fig. 2 is a similar view of a counter stiffener formed to the last. After the shoe is lasted, the blank; Fig. 3 is a plan of an apparatus for subjecting part of the upper which contains the stiffener blank is subjected to radiant heat to fuse the the front and» rear portions of the upper of a shellac whereby the particles of shellac are 50 lasted shoe to the heating e?‘ect of a high-fre 2,406,738 4 quency field, a shoe being shown in place, certain parts of the apparatus having been removed or the stitching room. The upper may then go through the regular shoe manufacturing opera broken away; tions, including being mounted upon and con Fig. 4 is a vertical longitudinal section of the formed to a last; and, at any time after the last apparatus and lasted shoe shown in Fig. 3, the ing has been completed, the toe and heel ends plate 69 which has been removed in Fig. 3, being of the upper, with the conformed, limp sti?ener therein, may be subjected to the heating effect of shown; Fig. 5 is a perspective of the rear electrode a high-frequency ?eld. holder with the electrodes; The resinous sti?ening material, as has been Fig. 6 is a vertical cross-section through the 10 stated, is preferably incorporated inselected por tions of the upper by incorporating two separate rear part of the apparatus and the shoe which are shown in Fig. 3 ; and Fig. 7 is a vertical cross-section through the forward part of the apparatus and shoe. The stiifenerblanks (Figs. 1 and 2) are pref erably made by impregnating a sheet or porous base, such as cotton ?annel, felt or paper, with a solution of a plastic stiffening material consist ing essentially of a synthetic resinous material, stiffener blanks such as are shown in Figs. 1 and 2. In Fig, 6 a lasted upper is indicated at I", a stiffener at 200, a lining at 300, and a last at "l. 15 After the sti?eners have been incorporated in the upper and the upper has been lasted, the next step is to subject the selected portions of the upper to the heating e?ect of a high-frequency ?eld. A convenient method of accomplishing such, for example, as ethyl cellulose, in a solvent, 20 this will now be described inconnection with a suitable apparatus. such, for example, as acetone; treating the im Referring ?rst to Figs. 3 and 4, the apparatus pregnated base with a non-solvent liquid, such, comprises a base 9 upon which are mounted a for example, as water, which is miscible with the front section and a rear section. The front sec solvent but is not a solvent for the resinous ma terial, so as to precipitate the resinous material 25 tion comprises a block H‘ which is hollowed out to receive a ?exible rubber bag 13 shaped to receive the toe portion of a lasted shoe, said block being adjustable toward and from the rear sec tion in a guideway [5 formed in the base 9 and stices a resinous material may be carried out in held in adjusted position by a clamping screw any suitable manner, for example, as disclosed ii, the purpose of this adjustment being to pro in United States Letters Patents No. 1,256,240, vide for shoes of different lengths. The rear dated February 12, 1918, and No. 1,353,599, dated section also has a ?exible bag is which is shaped September 21, 1920, both granted upon applica to extend around the rear and sides of the shoe, tions of Stanley P, Lovell. The dry sheet carry and the wings or sides of which can be moved ing the resinous material in precipitated form, from open to closed position. Two electrode if stiffer than desired, may be rendered limp or holders 2|, 23, the details of construction of ?exible by any suitable treatment. For exam which will be described later, are placed respec ple, the sheet may be carried between moving tively upon the toe portion and the rear portion belts which make sharp reverse turns over small rolls so as to bend the sheet sharply ?rst in one 40 of the upper on the lasted shoe, and then the lasted shoe, with the electrode holders in place direction and then in another; or the sheet may upon it, is placed as shown in Figs. 3 and 4 with be run through a mangle and thus rendered limp the electrode holder 2! resting against the bag II and ?exible by reducing the precipitated resi and the electrode holder 23 resting against the nous material more or less to discrete particles. After the above treatment the stiffener blanks 4. bag IS, the block if having been adjusted hori zontally and locked in position by the clamping may be cut out of the sheet. It may be desired to omit the precipitating screw IT. A cover 25, which is hinged to the step, in which case the solvent may be caused to front section at 21, is swung over and down into horizontal position and fastened in this position evaporate, and the dry sheet containing the res by a hasp (not shown) on the cover, the slot in inous material treated to render said sheet limp. the hasp receiving a staple (not shown) driven It will be understood that the base, instead of into the block I I, a pin (not shown) being passed being a separate member, may be some part of the through the staple to hold the hasp in place. assembled upper of a shoe, for example, the dou bler, which has, for example, been cut out of an The cover 25 (Fig. 7) has set into it near its impregnated sheet. Also, if desired, the porous middle a block of resilient material 28 which base may be omitted, and limp, easily conform presses down the electrode holder on the toe porable stiffener blanks produced by spraying a tion of the shoe. A similar cover 3| (Fig, 3), suitable solution of a synthetic resinous material hinged to a stationary part 01' the rear section at in a suitable manner upon a smoothsurface, peel 33, is swung over and its hasp (not shown) held ing oil’ the comparatively thick, porous sheet 60 by a staple 35 which is driven into a stationary which results when the solvent has evaporated, part of the rear section. This cover 3| (Fig. 6) and cutting out blanks from such a sheet. In any has set into it near its middle 9. block of resilient case, there will be incorporated in the upper 01 material 31 which presses the electrode holder 21 a shoe a synthetic resinous material which while and the rear portion of the lasted shoe against cold and dry may be conformed with the upper 65 the ?exible bag l9. Next, the sides or wings of to a last and may be later caused to coalesce by the rear bag H are forced inwardly in a manner subjecting it to the heating effect of a high-fre presently to be described so as to press the sides or quency ?eld. wings of the rear electrode against the upper Limp stiffener blanks, for example, a toe stiff and the upper against the sides of the rear por ener blank (Fig. 1) and a counter stiil'ener blank tion of the last. (Fig, 2), may be incorporated in the upper of a In the manufacture of shoes it is usual to tack shoe at any suitable stage in the manufacture of an insole to a last, the heel end of the insole the shoe. Conveniently the blanks may be in being somewhat narrower than the widest part corporated in and become part of the upper dur of the rear end of the last so that there is a in the base; and then drying the sheet. The procedure outlined above for impregnat ing a porous sheet by precipitating in its inter ing the assembling of the parts of the upper in if , re-entrant angle which extends around the heel 9,406,788 5 Y and of the last and insole. said'angle (Pig. 6) beingboundedononesidebytheedgeofthe 6 . ' the electrode holder 28 ?rmly against the upper ‘of the shoe and the upper ?rmly against the last. insole Ill and on the other by the somewhat Fastened respectively to the tops of the arms curved surface at the bottom of the heel end of ill. I" are two thin plates u, ‘H; and fastened ' the last. It is desirable that the ?nished sti?ener to the top of the rear wall I1 is a third thin should bridge this angle; and in order that the plate 13, the inner edges of these plates extending sti?ener, while soft, shall not be forced into over the top of the bag II. The arms III, I" this angle, the inner wall of the bag at this are normally held in open or spread-apart posi locality is given sumcient rigidity. In the illus tion, as shown in'Fig. 3, by two tension‘ springs trated construction there is vulcanized or other 10 ‘ll, 11, one end of each spring being fastened to wise attached to the adjacent portion of the an arm and the other end to the base I. In order inner wall of the bag It a strip of resilient ma to move the arms to closed position against the terial 8|, wedge-shaped in cross-section, so that force of the springs ‘II, 11, there are provided no objectionable crease or depression appears in two cam members ‘II, II pivoted ‘respectively the outer of the ?nished shoe. 15 about the stems of screws 88, II which are With the shoe and the electrodes thus ?rmly threaded respectively into the side walls II. II. held, a ?uid under pressure, for example, com The cam members have comparatively long, pressed air, is forced through two pipes 4i and straight handles which. as viewed in Figs. 3 and 43 into the rear bag it and through the pipe 4, are upright, the springs ‘II, 11 holding the ll into the front bag I! to distend the bags. 20 arms ill, I" open. when it is desired to swing Thereafter the electrodes are energized from the terminals of an oscillator of a high-frequency the arms toward each other to exert pressure. the handles are swung down and outwardly about the pivot screws ll, 85. This causes the cam members, which are integral with the handles, to force the arms inwardly. Upon the upper face sure is twofold. First, it presses the electrodes, of the base 9 is a block 81 of resilient material which are ?exible, ?rmly into contact with the to receive the cone of the last 4". shoe, thereby rendering them much more effec The electrodes are flexible. They are sub stantially alike except for their shapes, and con tive. Second, it presses the outer, the stiffen ing material, and the lining of the shoe into ?rm 30 sequently only the rear electrode will be de contact with each other so that the three mem scribed in detail. The holder 23 for the rear electrodes has the general shape shown in Fig. bers arej ?rmly bonded together in the ?nished 5, being provided with curved side walls which shoe. The general construction and mode of opera resemble in shape those of a molded counter tion having been given above, a detailed de 35 stiffener, and with an intumed, substantially ?at scriptlon of the parts of the apparatus will now ?ange at the top. The inner wall of the holder thus corresponds roughly to the shape of the be given.‘ The block ll of the front section is rear portion of the last. The illustrated holder hollowed out, as has been explained, to receive the resilient bag I3. In order to aid in holding is made of two layers of ?exible material, such the bag properly in place, a suitably shaped thin 40 as leather, a thin layer 88 and a thicker layer 89, the thicker layer having in it a series of holes plate 41, the inner edge of which extends over the 90 to receive spirals of wire which constitute the top of the bag, is fastened by screws to the electrodes of the high-frequency machine. Con_ block; and a comparatively thick, substantially veniently, if desired, the layers of the electrode upright, but slightly inclined plate 49 is fastened to the block ll, said plate 49 having cut in it a 45 holder may be made of ?nely woven elastic glass, curved bevel-edged opening to ?t closely around and the electrodes fastened in place between the glass layers. These electrodes are arranged in the inner (left-hand as viewed in Fig. 4) end oi’ sets of two series of three each. To the three the bag IS. The pipe 45, through which com members of one set have been applied the ref pressed air is forced into the bag, has its inner end upset over one wall of the bag and is held 50 erence numerals 9|, and to the three members ?rmly in place by a nut 5| which is threaded .ofthe other set the reference numerals 93. The upon the pipe. ' three electrodes 9i are connected to three con machine whereby the resinous stiffening material is caused to coalesce and, ?nally, becomes hard, ?lm-like, and resilient. The purpose of the pres ductors I91 which in turn are connected to a The rear section is different from the front section principally because means are provided single conductor 2M, said last-named conductor for causing the sides or wings of the bag 19 to 55 leading from one terminal of a high-frequency press the electrode holder against the sides of oscillator. The three electrodes 93 of the other the rear portion of the shoe. This rear section set are connected to three conductors I93 which comprises two stationary, upright side walls 53, in turn are connected to a single conductor 293, I5 and a stationary, upright rear wall 51, all said last-named conductor leading from the other three walls being rigid with the base 9. The rear 60 terminal of the high-frequency oscillator. It wall has rounded ends which are adjacent to but will be noted that the three electrodes 9| are somewhat spaced from the side walls 53, 55. alternated with the three electrodes 83, and that These rounded ends have horizontal slots about direct ?elds lie between these electrodes. It is midway of their height, one such slot being shown not, however, such direct ?elds which are relied at n in Fig. 4; and extending vertically through 65 upon to heat the stiffening material in the shoe. the rounded ends and the slots are vertical pivot There is present a series of stray ?elds extend pins, one of which is shown at BI and the tops , ing outwardly and inwardly from the planes be of both of which are shown at II and 83 in tween the electrodes, these stray ?elds being Fig. 3. Extending horizontally into the slots and parts of the electrostatic ?elds which are ex pivoted on the pins are ?at tongues 85, 01 formed 70 ternal to the space between the electrodes, and respectively on the rear ends of arms I85, it‘! it is this, series of stray ?elds which is principally which receive between them the sides of the bag relied upon. The forward electrode holder is of I I, as shown in Fig. 6, in which ?gure the arms substantially the same construction as that of have been swung in about their respective piv the rear electrode holder which has just been de ots ll, '8 to cause the sides of the bag to press 75 scribed, but differs from the rear holder in that 2,406,738 7 it is shaped roughly to correspond to the shape Polyvinyl acetate R. H. #410 is~a polymerized of the toe portion of a lasted shoe. The con vinyl acetate put out by the E. I. du Pont de ductors for the two sets of electrodes of the front Nemours 8: Co., Inc., of Wilmington, Delaware. holder M are indicated in Fig. 3 at 95 and 81. Example VI The following are examples of solutions which 5 Parts by weight may be used to impregnate a porous base. Example I Normal propyl methocrylate ______________ __ 35 Acetamide ______________________________ __ 12 Parts by weight Ethocel 100 C. P. Standard _____________ __ 16.25 m Rosin (cherry wood) __________________ __ 5.25 Acetamide 6.75 Acetone ___________________________ __ ____________________________ __ ________________________________ __ 80 Example VII _ _____________________________ __ 75 Methanol Acetone Parts by weight Normal butyl methacrylate _______________ __ 35 15 Acetamide "Ethocel 100 C. P. Standard” is ethyl cellulose 15 Acetone put out by the Dow Chemical Co. of Midlands, Michigan. The rosin is used principally to add to the tackiness of the compound. Acetamide is _____________________________ __ 12 __, ______________________________ ..- ' 80 Example VIII Parts by weight Ethocel 100 C. P. Standard ________________ __ 16 a compound which has a lower melting point than'the “Ethocel" and is more susceptible to 20 Rosin (cherry wood) _____________________ __ 12 Hycar __________________________ -.‘ ______ -_ 6 the heating e?ect of a high-frequency ?eld than is the “Ethocel.” Its principal function is to Acetone cause the “Ethocel” to melt at a lower tempera Methanol ture than it otherwise. would. Example II ' > ______________________________ ..- 20 Example IX 25 Parts by weight Ethocel #250 C. P.‘ Standard _____________ __ Petrex ________________________________ __ 90 15 - Parts 'by weight Ethocel 50 C. P. Standard ________________ _- 24 Rosin (cherry wood) __________________ "s... 12 Hycar __________________________________ __ 6 acid _____________ -__ ________ __'____- 6 ‘Acetone ________________________________ __ 90 Acetone _______________________________ __ 100 so Methanol Methanol __________ _.' _________________ __ ______________________________ .. 20 28 In this formula, “Petrex acid" is used in. place of_acetamide and rosin. This acid is a high Hycar, a synthetic rubber, is a butadiene acrylonitrile copolymer containing in the neigh borhood of 25% by weight of acrylonitrile and molecular weight, synthetic, polybasic acid of 75% by weight of butadiene put out by the Hycar terpene origin put out by the Hercules Powder 35 Chemical Company of Akron, Ohio. Like Co. of Wilmington, Delaware. acetamide it has a lower softening point than Example III has the ethyl cellulose. The synthetic rubber renders the stiil’ener blank more pliable when cold so that the lasting operation is facilitated, Ethocel #150 C. P. Standard ____________ __ 16 4o and enhances the resilient quality of the finished Polypale ester No. 2 _____________________ __ 12 stiffener in the shoe. Acetone _______________________________ -_ 140 Parts by weight Methanol ______________________________ __ Example X 28 In this formula “Polypale ester No. 2" is used, in place of acetamide and rosin. This ester is 45 the diethylene glycol ester of polymerized rosin and is also put out by the Hercules Powder Co. Parts by weight Paraplex X100 __________________________ __ Durez resin #12687 ______________________ __ Benzoyl peroxide _______________________ __ Altax Example IV Parts by weight 50 Ethocel 250 C. P. Standard ______________ __ Rosin (cherry wood) ____________________ __ 10 10 40 70 1 _________________________________ __ 1 Titanox R. A. 10M0 _____________________ __ 50 Acetone _______________________________ __ 134 Methanol ______________________________ -_ 24 Paraplex X100 put out by the Resinous Prod Acetone _______________________________ __ 120 ucts 8: Chemical Co. of Philadelphia, Pa., is an Methanol ______________________________ __ 24 alkyd type thermosetting resin having a soften Rosin, besides adding to the tackiness of the 55 ing range of from 100° F. to 105° F. Durez resin compound also is more susceptible to the heat #12687 is a thermosetting phenol-formaldehyde ing effect of a high-frequency ?eld than is the resin, put out by Durez Plastics & Chemicals, “Ethocel.” It will be noted that no acetamide, Inc., of North Tonawanda, New York, which has "Petrex acid” or "polypale ester" is present in a softening range of 40°-60° C. and a melting the formula, the large proportion of rosin in this 60 range of '70"-75° C. Benzoyl peroxide is an ac case acting to increase su?iciently the suscepti celerator for the curing of the thermosetting res bility of the “Ethocel” to the heating effect of inous material. Altax, benzothiazyl disul?de, put the high-frequency ?eld. The above formula out by the R. T. Vanderbilt Co., of New York, produces a stiffener which, when hot, is some N. Y., is a rubber accelerator but here probably what more sticky than that produced by Example acts to retard somewhat the curing operation. I and one which will soften at a somewhat lower Titanox R. A. 10M0 is a titanium oxide put out temperature, but not below that to which the stiffened portion of a ?nished shoe is liable to be by the ‘Titanium Pigment Corporation of New exposed. ' Example V York, N. Y. It serves here principally as a filler. This application is a division of application 70 Serial No. 564,605, filed November 22, 1944, and is directed to the apparatus. Parts by weight Having described my invention, what I claim Polyvinyl acetate R. H. #410__' ____________ __ 45 as new and desire to secure by Letters Patent of Acetamide ______________________________ __ the United States is: 15 Acetone ________________________________ __ 90 75 . 1. Apparatus for use in stiffening the front and 2,406,788 9 rear portions of the upper of a lasted shoe, there being incorporated in the two portions non-fused resinous stiffening material capable of being caused to coalesce by heat, said apparatus com ' prising two supports including yielding members against which the two portions‘ 0! the shoe rest, means for exerting pressure through the ?exible members upon the two portions of the upperto press them against the last,’and means for sub iecting the pressed portions to the heating effect 10 of a high-frequency ?eld; 2. Apparatus for use in stiffening the front and rear portions 0! the upper of a lasted shoe, there ~ 10 5. Apparatus for use in stiifening a selected portion of the upper of a lasted shoe, said se lected portion having incorporated therein a non fused stiffening material capable of being caused to coalesce by heat, said apparatus comprising a ?exible electrode holder shaped to fit about the selected portion, an in?atable bag shaped to ?t about the holder, means for supporting the bag in such manner that, when in?ated, it will press the electrode holderagainst the selected portion of the upper and the selected portion against the last, said bag-supporting means including members of rigid material movable toward and from each other, means for in?ating the bag, being incorporated in the two portions non-fused resinous stiffening material capable of being 15 and means for connecting the electrodes to the terminals of a high-frequency oscillator. caused to coalesce by heat, said apparatus com 6. Apparatus for use in stiffening a selected prising two supports including yielding members portion of the upper of a lasted shoe having in against which the two portions of the shoe rest, corporated therein a non-fused sti?ening, mate means whereby one support may be adjusted to ward and from the other to provide for shoes of 20 rial capable of being caused to coalesce by heat. said apparatus comprising a ?exible electrode different lengths, means for exerting pressure holder having two sets of electrodes in its wall. through the ?exible members upon the two por the electrodes, of one set being alternated with tions of the upper to press them against the the electrodes of the other set, said holder being last, and means for subjecting the pressed por shaped to ilt over the selected portion of the shoe tiolnls to the heating e?ect of a high-frequency and to extend over the bottom thereof, a ?exible ?e . bag embracing the holder, means for holding 3. Apparatus for use in sti?'ening a selected the outer wall of the bag from movement away portion of the upper of a lasted shoe having in from the shoe, means for in?ating the bag to corporated therein a non-fused sti?ening ma terial capable of being coalesced by heat, said 30 press the electrode holder against the bottom and side portions of the upper, and means for apparatus comprising a ?exible electrode holder connecting the two sets of electrodes respec having two sets of electrodes in its wall, the elec tively to the terminals of a high-frequency oscil trodes of one set being alternated with the elec lator. trodes oi the other set, said holder being shaped v'7. Apparatus for use in stiffening a selected to ?t over the selected portion of the shoe, means portion of the upper of a lasted shoe, said por for pressing the ?exible electrode holder against tion having incorporated therein a non-fused the shoe, and means for connecting the sets of sti?ening material capable of being caused ‘to electrodes respectively to the terminals of a high coalesce by heat. said apparatus comprising a irequency oscillator. 4. Apparatus for use in sti?'ening a selected 40 ?exible member, means for causing said mem ber to press the selected portion against the last. portion of the upper oi a lasted shoe, said selected said ?exible member having a part of su?lcient portion having incorporated therein a non-fused - sti?ening material capable of being caused to coalesce by heat, said apparatus comprising a . ?exible electrode holder shaped to ?t about the selected portion, an in?atable bag shaped to ?t about the holder, means for supporting the bag in such manner that, when in?ated, it will press the electrode holder against the selected portion of the upper and the selected portion against 50 the last, means for in?ating the bag. and means for connecting the electrodes to the terminals oi a high-frequency oscillator. rigidity located to bridge the re-entrant angle bounded on one side by the edge 01' the rear part oi! the insole and on the other by the curved surface at the lower portion of the rear part 0! the last. and means for subjecting the selected portion while under pressure to the heating effect of a high-frequency ?eld. some J. BROPHY.