US905105A - Rubber footwear. - Google Patents

Description

unirsi) s'rn'rns raannr Iernten.

EMME'IT A. SAUNDERS, OF SOUTH BEND, INDIANA.

1 RUBBER roo'rwnaa@l Specication o f Letters Patent.'

i Patented Nov; 24, 1908.

original aplilieaapn niea February 24, 1905. serial'No.. 247,101. Divided and this appresa@ ala June 17, isos.

To .all whom 'it may concern:

Be it known that I, Enns'r'r A. SAUNDERS, a citizen of the lUnited States,'residing in South Bend, Indiana, have invented a eertain new and useful yImprovement in Ruhber Footwear,` of which the 'following isa specification. d

' This-invention has relation to integral or seamless rubber boots and shoes., .whether i n g lntherto used 1s alsoopen to objections.

lined with fabric or unlined. The principal object of. the invention the production of improvedrubber footwear which, by reasonv of its seamless character,

vhasnone of the disadvantages of a' perma-v nently cemented vlarticle; 4and wherein the u nder parts of the shoes onthe one hand and the entireuppers on the other handV possess each the peculiar characteristics best adapted totheir own necessities under conditions of use.

Seamless rubber footwear has been hitherto manufactured by building up thewhole boot orshoe on a last and vulcanizing the partsall together to produce an integral article of manufacture. In. vsome cases this vulcanifzation takes place lby exposure "to l open heat in a proper` oven. In other cases a mold is provided whchincloses the entire booter shoe and wherein it is sub- `je'cted to simultaneous heat and pressure to accomplish vulcanzation. v i p e The present invent-ion aims 4to overcome certain .disadvantages unavoidably incident to both of the above named modes vof treat` ment. These maybe stated as followszThe main objection to Vulcanizing an entire shoe by open heat in an oven' lies inthe fact that all green rubber compounds contain more or less moisture and other materials "which form 40 sequence, when a rubber shoe is vulcanized by. open heat these gases open up cells .within the rubber=walls,giving the whole a more' or less 'spongy texture. The thin parts of the shoe contain yless gas-producing fluids than thethicker portions, owing to the greater expressive effect of the forming rollers or calenders on thin sheets than.' on thicker masses. 'during vulcanization is not' noticeable in these thinner portions', and such lack of solidity as does exist is rather beneticial than otherwise, as it promotes elasticity and pliability. The thicker portions of the shoe, 56 however, 'containing as they do a greater serial No.' 265,724.

'or wrinkle when-0n the foot.

'expansible gases on 'being heated.l In con-I` Hence -lthe sponginess' developed amount of moisture etc., suffer a greater expansion and are converted into ,rubber .Sponge covered with a thin outerlayer offrmer. ma-

terial. WearsoonY penetrates this latter4 and before long al th1ck`sole so made often absorbs and so to speak pumps lup water into its interstices with every step. The result vof this, of course, is a rapid deterioration.

VThe second process above mentioned and Wiere the entire shoe is placed in a mold for vulcanlzation under pressure, the spongi- `ness above mentioned 1s prevented in the thickerparts but the softness is also .snppressed in the thinner portions of the shoe. As heretofore mentioned, this softness is beneficial in thethinnerv walls, and its suppression tends to bri-ttleness in the very parts which must 'be allowed to yield when the shoe is taken olf or put on, and must bend Another important disadvantage met with in this prior process is that the thicker parte, including the heel, thesoleand those portions of the remainder of the` shoe in direct Contact therewith, require more prolonged action than the uppers. f It results from this that either the uppers are overc'ured during a `given treatment, or the aforesaid thicker 4portions are not suiciently vulcanized. If

the uppers are overcured they are hard, inelastic and unyielding and, as the strains of wear 'on the uppers are pulling` and bendin strains, quick deterioration is the result. I on the other hand, the thin uppers are not vulcanized too hard, the thicker parts atsole and heel are left too`soft for resisting the lwear to which they are subjected. This wear takes the forni ofshock and abrasion, and a tough, hard, relatively nnyielding condition best in these portions of a hoot or shoe.

By the practice of my present invention l Iam able to produce shoe having :i soft ,elastic and. pliable texture in the thin walls ofthe upper portions but #free from spuug-y or'cellular structure in those thicker port ionsl to resist shocks and abrasive action.

g In making my improved shoe I may make `use of any desired apnaratrls whether novel or well known, and anexalnple of suitable 4means is illustrated"` in the accompanying at-th'e bottom of th'eshoe which :1re intended with a shoe on its last shown in the operating position and Fig. 2 is a pers ective view of a rubber sole ready for app ication to a shoe in the mold shown in lFig. 1.

The body ofthe shoe including the inner sole all shown at 1 in Fig. 1, is built up in the usual manner on a last 2, being constructed of properly shaped parts temporarily cemented together.

The thick outer rubber sole 3 is separately prepared, being keither formed reen or partly vulcanized in a press ina we l'lmown manner. The sole shown in Fig. 2 is a typical example of this part as prepared for application" to the shoe. It is concave in transverse section to lfit the convexity of the shoe body, and is preferably provided with an upturned edge 4, which is adapted to fit closely all around the lower edge of the shoe body. The form of sole illustrated isnot essential to my invention the sco e of which covers the use .and application o a mere tap sole or of a-heel alone.

The shoe body and the thick lower part to be applied thereto having been thus separately prepared, the latter is placed in a mold 5 into which it fits snugly, which mold is combined with means for pressing the shoe body, while still on the last, down onto the sole im said mold.

In the illustrative form of apparatus shown in the' drawings, this takes the shape of an arch 6 fitted with a screw 7 having a hand wheel 8. The last with zthe shoe body upon itis placed upon the sole 3 so as to tit within the upturned edge '4 and the screw 7 is turned down hard upon it. The action of the convex body when thus forced down into the concave sole when in the mold 5 is to create a pressure between the soft'meeting surfaces at all points, and thus the sole is pressed upon the shoe body, not only on the,

under surface, but horizontally along the entire length of the upturned edges 4.

In order to carry out my process, the mold must be heated to a proper vulcanizing temperature and this may be accomplished in any manner desired. In the ap aratus shown in the drawing the mold 5 is ho low-as shown and the heat is supplied by steam entering for instance at 9 and returning at 10.

By the means above described there is created a strong continuous pressure which is preserved during the period of vulcanization of the lower shoebody and joined surfaces, or until this process has been carried so far that the material is able, of its own re'- sistance to suppress all formation of sponginess under the further influence ofI heat. Then the rubber reaches this last named condition it may be said to set. lThis word is intended to express a suiiicient degree of e employed. i In the following claims the term sole is vulcanization to prevent sponginess on application of further heat. y Local vulcanization in a mold asabove described must be continued at least to such a n an evenmin out vulcanizing -temperat y," l

ssureg" The sole and the application o heel being set, therieigisv'n dangerpeof sponge therein and the.` manufacturer isfree to secure the best-'results in 4the uppers without danger to therema-inder fthe shoe.

The apparatus whereby my process is carried out forms no part .of this invention, as Vany form of machine ap ropriate to accomlishment of the steps a ove described may intended to cover either the tap sole or heel or bothtogether and whether extending up- W'ard on the side of the shoe body or not.

. The process herein described is claimed in my pending application for patent Serial Number 247,101, filed February 24th, 1905, of which this is a division.

What I claim is- 1. As an article of manufacture, an integral rubber boot or shoe havin uppers of thin soft and elastic texture an outer and inner soles with contiguous parts of solid and relatively inelastic material, substantially as described.

2. As an article of manufacture, an integral rubber boot or shoe in which the sole and contiguous parts are made of compressed and vulcanized rubber while the uppers are made of rubber vulcanized without pressure, substantially as described.

3. As an article of manufacture, an integral vulcanized rubber boot or shoe having a compressed long-cured sole and contiguous parts and having uppers cured for less time and without pressure, substantially as described.

4. As an article ff manufacture, a rubber boot or shoe, havmgthe insole, outer sole and uppers vulcanized together in olie piece, and wherein the insole and outer sole arc of molded rubber vulcanized under pressure to the edge of the upper, and the upper is composed of elastic unmolded rubber, substantially as described.

EMMETT A. SAUNDERS.

Vitnesses HAROLD A. MACKAYE, FLORENCE S. Pioli.

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