US2370502A - Shoe last - Google Patents

Description

Feb. 27, 1945. M. G. STRATTON SHOE LAST Filed Jan. 13, 1944 Patented Feb. ,27, 1945 :Tliis; inventionrrelatesa-tm theirmanu facturew of tootwear :in WhiQhr: an: adhesivexisv-iheated v instan eleetrostaticefield, and: relates. more particularly to lasts having incorporated therein,-.-e1ectrodes ion-use, in establishingvelectrostaticmfielqs.

fines-E. .ca Pi-tman.-:R.eissue-.-Batent N0.@22,301 discloses;Tprooesses for-bondingashoe parts-With --.ther mop1astic .-;adhesives heated by f electrostatic esfields. The J:v FJSmith Batent No. ,2;1'09,32?,dis-

closes-i apparatus for carryin g out such processes inetheumanufacture of #511095. -.The= J F. Smith Batenti -No. 2,24Q,867;-disc1oses ea, last-having an I electrode =-.;attaehed to, its ,lowerxsurface, lwhich :mayrber used insuch apparatus.

It% :is desirable in electrostaticl heatingto have 1- an electroderiomtherbottom of a; last, whichrexa-tengistalongz :theTentir-e lengthiof: the -fo.repart=por- ;tion-, of the: lasteand-talongw a, portion oL-the. ad-.

A joining heel portion of the last. Such electrodes vhave! been f-satisfactori-ly provided on, lasts -whiche tare anotaof the: hingedqtype but .rhave-inot t-been ,satisfactorily providedrfor. hinged .wiasts. sWith hingedlastsrseparate electrode-portions haveibeen .tprovidedron the bottoms of the heel: and :forepart ,portions of ether last,---which electrodes have :not

..been. in good electrical con-tactwhenthelasts [were rbroken; evenhslightly as oftenaoccurs due, to-the "ttheilast." the relativesmovementsofnthe or,epart andiheel portions ofjthejast duringthepressin o er ions; has resnltedini thegcimuit,to...the e1ectrode on the bottom ofthe forepartpprtion.oLthe .last being poorly. made or,br oken withgthe result that insu'flicient orno. heat was, enerated inane adhesiveihthfi iorepart'. area of: the, shoe.

TThis invention provides. ifonmaintainin it-positive-.-'. e1ectrica1 conneotionmetween.rthe eleetrode ontheiforepart portion. oflfthebottom oia hinged' *Jast and an, electrode in'thel he'el portion; thereof,

"which; connectionnis maintained: throughoutlthe fullfrangepof movement, of thesaid two portions .9f the lastt relativeieaph other. iI-Lhis connection is maintained attheehingesoii the last.

"T.TwoembtidimentshLthe inventienareidis'closedher.ein, lnebo'th embodiments theielectrode surfaces preferably are formed. by sprayedtmetal. pareticlesaand ,thenmetal .linerinLlthe conventional v ja'ok rpin holewinLthe heeLportionQoithellastpref- .terablym is.r.e1ied upon -forestahlislfirigmlectricah (cine-e133) -oontaet-betweentheelectrode on the" 'last bottom I and thewiring w the usualhigh frequency elec- .trical source which is provided foz establishing the electrostatic field: g In--one embodimentgoff the "invention, 1 a metal gsereW- extends frornthedowersurface of the fore- "part of the last into't-hedast interior and iselec- --t'rica'11y'- connectedtherein-at the hinge ofthe-last to the levers which a'ttaeh the heel and-'-forepa1't portions of thelast together and-which are pivoted thereto. ""I-he"=1evers are electrically connected to o theaforesaid-metal liner. 'Ihespravwhich forms I the electrode surface contacts the head of said t,screw v k v ln' the other embodiment of the invention, the forepartand-heelrtportions-of the hinged last have eom'plementai 'eircular, hinge segments nWhiCh conta'ct eaehJ'idther throughout-t their-;range oof wmovement aridmhich: are: sprayed with 1311821119- :tauic spray- $06 that e1ectrica1 contact between the last is! alsousprayed arwith the metallic-apar- :iticles with the spray-being: continued"intheflareas azbetweencthetbottormzof the aforepart and heel-:portions of theslast so-zas; to oontactithe :sprayedpori tions ofi the -saidrseg-ments, therspray also being roontinued; SOzfls: torcontact. the eonvenitonahmetal rrheelnplate. rzzThe v heel :plate 1 -is.- electrically coonnected to the metal liner in the jack-pinholeyand vthe .-1iner ;is2c.onne,eted to a terminal for; connec- :utiQn .:.'to:.:the.-h;igh fre'quen sy-.e1ec-triea1 seurce.

mAn sobJentrotmthe/invention1is .to maintain telecricalacontaetebetweenaelectrodeisurfaces in the 1 ottom oitaihinged shoe last'throughout the range o movement-relative; each other, oft-the heeland -*.:forepart-portionsofthe last. I a

, fIheainve-ntion vwill nnoyvsbet described with: ref Ieereneeto thetdrawing; oitwhieh: v

.7 Fig.1 l-uisa-side elevatiQ'n, rpartiallyhin :sec,tion, rod-of; a shoe last embqdving this invention;

' ,Fig. 2 is-.a plan.view.looking'r-atdthebottom of the 1astof.Eig.. V v sE e'a eis a sideielevation partiall in section, phenomen -last.embodying this invention; and Eigiarisaplantview lookingtatitheibottom of the lastoiliigfi. I v I g I 5 Reierring,firstatojFigsLand; 2', ,the lasteillusattained-maybe a. conventionalrhingedflwoodenlast vv having; theflheel portion; 5 and,.the fore portion 5 pivoted for movement relative each other.

eThe.v forenportion fi io f, thefllast .isihollowed out at ,8 to, mecei-ve'ntheemetal arm. 9.,whichflis, pivoted oj ateoneeeniabout the .pivotepin 12 to the metal .arms gl SrandWhich ispivoted tovthe forepart porstion .ofthe lastbythe pin 1 .0.

fore portion 6 of the last into the opening 8 and contacts the pin III with its inner end. The head of the screw H is flush with and is made to conform with the contour of the last bottom at its.

is attached to the inner end of the rod IS. The outer end of the rod #5 contacts the metal pin 30 which connects the metal liner H5 in the usual jack-pin hole to the heel plate 2! of the last.

. metal liner l6 and with the heel plat 2| of the- The arms Sand l3 are the usual arms employed in the type of last illustrated by Figs. land 2 for holding the heel and forepart portions of the last together at the hinge thereof. The screw 1 H and the rod l5 are added for establishingthe aforesaid electrical connections to the forepart portion of the last.

The metal plate I1 forming a portion of the heel postof a shoe pres contacts the upper end of the liner l6 as illustrated and is tapped to receive the threaded terminal post 18 to which the lead l9 to a suitable high frequencyelectrical' source, is connected by the screw 20.

The bottom of the last between the heel plate 2| and the toe end of the last is roughed as by the application of a conventional shoe roughing tool, around the marginal edges of the forepart and in the shank area, and a metallic layer 22 is formed on the roughened area as illustrated by Fig. 2 by metal particles sprayed from a conventional spray gun. The sprayed coating .is continued over the inner portion of the heel plate 21 for establishing electrical contact therewith. This metallic area contacts the head of thescrew l I, and an electrical connection to the terminal screw 20 from the metallic layer 22 is established throughthe screw H, thepin lfl, the arm 9, the pinl2, the arms l3, the pin M, the rod [5, the rod 30, the liner l6 andthe post I 8. Thi connection is maintained when the last is broken and during-any lesser movement of the heel and forepart portions'of the last relative each other."

In' the embodiment of the invention'illustrated The screw ll extends from the bottom of the female portion 28' of the hinge and in the area between same and the bottom.

Likewise the inner portion of the bottom 0 the heel portion 5 of the last is sprayed with the spray continued on the surface of the male portion 2'! of the hinge on the heel portion and in the area between same and the bottom thereof. The'spray is also continued over the inner portion of the heel plate 2| for establishing electrical contact therewith.

The metal pin 30 extends in contact with the last of Figs. 3 and 4. The electrical circuit from one side of the high frequency electrical source to the sprayed layer 22 on the last bottom extends through the wir [9, the terminal screw Zll, the terminal post 16, the metal plate H, the liner l6, the pin 30, and theheel plate 2|. This circuit is maintained regardless of the movement of the fore portion of the last relative the heel portion since the sprayed layers on the male portion 27 of the hinge of the last and on the female "portion 28 thereof remain in contact during such at low cost but the electrode surfaces conform readily to the curved surface of the last bottom and do not add'appreciable depth to a last so that theconventional wooden last not having a metal bottom may be easily and cheaply provided with an electrode surface and still be :used with the,

shoe for which it was originally designed.

While embodiments of the invention have been {disclosed for the purpose of illustration, it should be understood that the invention is'not limited tothe exact apparatus and arrangement of apparatus illustrated, as modifications thereof may be suggested by those skilled in the art without departure from the essence of the invention.

Having described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. A non-metallic shoe last for use in the'elec-- trostatic heating of adhesive-between shoe parts and having hinged heel and forepart portions,

by Figs. .3 and 4, the heel portion 5 of the last has the pivot pin 24 extending crosswise therethrough and to which are rotatablyattached' the arms 25 at one end thereof. The fore portion G'of the last has the pivot pin 26' extending crosswise therethrough and the other ends of the arms 25 are rotatably attached thereto. The arms 25 are the usual type employed in the form of last illus trated by'Figs. 3 and 4 for holding the heel and forepart portions of the last'together at its hinge;

The hinge of the last has the rounded male portion 21 at the inner end of the heelportion 5 thereof, formed as a segment of a cylinderand has the corresponding female portion 28 formed complemental thereto on the forepart portionof the last. The arms 25 and thepivot pins 24 and 26 hold the heel and fore portions of the last together when they are moved with" respect to each other, with the hinge portions 21 and 28 in contact. v

For applying the electrode surfaces the heel and fore portions of the last are disassembled by removal of the pivot pin 26. The bottom of the forepart portion is then sprayed with metal particles and the spray is continued around the comprising means forming metal surfaces attachedto the bottoms of said portions, means including means extendin within the heel porsource, and means including means at the hinge of said last for electrically interconnecting said surfaces whereby electrical connection between sameis maintained when said last is unbroken and is broken. I

til)

said last, means including. means forming an electrical connection extending within the heel portion of said last for establishing an electrical circuit to a high frequency electrical source, and means including means at the hinge of said last for connecting said surface andsaid connection whereby an electrical circuit is maintained from 7 said connection to said surface when said last is unbroken and is broken. 3. A non-metallic shoe last for use in the electrostatic heatin of adhesive between shoeparts and having hinged heel and forepart portions with pivoted metal arms interconnecting said portions at the hinge thereof, comprising means forming a metal surface attached to the bottom of the forepart portion of said last, means including means extending within the heel portion of said last forming an electrical connection for establishing an electric circuit to a high frequency electrical source, and means including said arms for connecting said surface and said connection whereby an electrical circuit i maintained from,

said connection to said surface when said last is unbroken and is broken.

l. A non-metallic shoe last for use in the electrostatic heating of adhesive between shoe parts and having hinged heel and forepart portions with pivoted metal arms interconnecting same at the hinge thereof, said heel portion having a metal liner in the jack-pin hole thereof, comprisin means forming a metal surface attached to the bottom of the forepart portion of said last, means including said liner for establishing electrical connection to a high frequency electrical source, and means including said arms for electrically connecting said surface to said liner whereby an electrical circuit fromjsaid liner .to said surface is maintained when said last is unbroken and is broken.

5. A non-metallic shoe last for use in the electrostatic heating of adhesive between shoe parts and having hinged heel a d fo epa portions with pivoted metal arms interconnecting same at the hinge thereof, said heel portion having a said portions having complemental, curved hinge portions with surfaces which are in contact when said last is unbroken and is broken, means formportions of said last, means electrically connecting the said metal surface on said curved portion means including said liner for establishing electrostatic heating of adhesive between shoe parts and having hinged heel and forepart portions with pivoted metal arms interconnecting same at the hinge thereof, said heel portion having a metal liner in the jack-pin hole thereof, comprising means forming a metal surface attached to the bottom of the forepart portion of said last, means including said liner for establishing electrical connection to a high frequency electrical source, and means including said arms-and including a metal screw having its head end flushwith and contacting said surface for electrically connecting said surface to'said liner whereby an electrical circuit from said liner to said surface is maintained when said last is unbroken and is broken. I

'7. A non-metallic shoe last for use in the elec-' trostatic heating of adhesive between shoe parts and having hinged heel and forepart portions,

of said heel portion of said last with the said metal'surface on the bottom thereof, and means electrically connecting the said metal surface on.

said' curved portion of said forepart portion thereof, with the said metal surface on'the bottom thereof.

' 8. A non-metallic shoe last for use in the electrostatic heating of adhesive between shoe parts and having hinged heel and forepart portions, said portions having complemental, curved hinge portions with surfaces which are in contact when said last is unbroken and is broken, means forming a metal surface attached to the bottom of said heel portion which continues on the surface of said curved hinge portion thereof, and means forming a metal surface attached to the bottom of said forepart portion which continues on the surface of said curved hinge portion thereof.

9. A non-metallic shoe last for use in the electrostatic heating of adhesive between shoe parts and having hinged heel and'forepart portions, said portions having complemental, curved hinge portionswith surfaces which are in contact when said'last is unbroken and is broken, means forming metal surfaces attached to said surfaces of said portions, means forming metal surfaces attached to the bottoms of said heel and forepart portions of said last, means electrically, connecting the said metal surface on said curved portion of said; heel portion of said last with the said metal surface on the bottom thereof, means electrically connecting the said metal surface on said curved portion of said forepart portion of said last with the said metal surface on the bottom thereof, and means including means extending Within said heel portion and electrically contacting said metal surface on the bottom thereof for establishing an electrical connection to a high frequency electrical source.

10. A non-metallic shoe last for use in the electrostatic heating of adhesive between shoe parts and having hinged heel and forepart portions, said portions having complemental, curved hinge portions with surfaces which are in contact when said last is unbroken and is broken, means forming a metal surface attached to the bottom of said heel portion which continues on the surface of said curved hinge portion thereof, mean forming a metal surface attached to the bottom of said forepart portion which continues on the surface of said curved hinge portion thereof, and means includin means extending within said heel portion and electrically contacting said metal surface on the bottom thereof for-establishing an'electrical connection to a high frequency electrical source.

MICHAEL G. STRATTON.

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