US2128774A - Manufacture of stitched and cemented footwear - Google Patents

Description

Aug. 30, 1938.

F. HOLLAND MANUFACTURE OF STITCHED AND CEMENTED FOOTWEAR Filed Sept 26, 1935 Jam/anion I BY 7: W .A- 645% Patented Aug. 30, 1938 :mrem

MANUFACTURE .OF

s'rrronnn l AND on- M'ENTED FOOTWEAR Friedrich .HolIanG B'rocht n,

, Mass, assignon ,to

' 'C0mpo Shoe Machinery Corporation, New

Yo rk, NrYifacorporation of Delaware Application September 26, 1935, Serial No. 42,180

4 Claims.

Thisinvention relates to the manufacture of footwear andrmore particularly to the lubrication, strengthening and protection of stitching used in such footwear.

Aprimary object of 'theinvention is to provide animproved method for lubricating shoe stitching which is laterto contact a coating suchas pyroxylin cement or the like.

Further objects of the invention are to provide M, animproved meansfor protecting shoe stitching against soiling during passage of .the work through the factory, while assuring a firm bond between the stitched shoe parts.

,,Another object of the invention is to provide n1 a method of making a welted shoe wherein the l outsole is aflixed to thewelt by means of cement, ,andwherein the inseam stitching is particularly .adapted to provide, and permitv a strong and gsatisfactory bondhetween thG'fShOB parts in its wicinity,

, Xetanotherobiede e in entioni t me- I vide a w-elted shoe wherein thewelt is attached 15119 thela te p brme e stitching an th outsolel ta he b v a s o cement 1 and in which a lubricant is provided for the incfifia .S i QhiU W C ha an \a t o r is empatjible w t th ce en use t ra t the .qu sol Qfill i ob ects oil-t in en i iwill in pa b ;lo ri9uaand 1 1 in. par a ea hereinafter- The i ventio eceotd n com i t sev- ,.er eP and the re ati -o on m r of Such WPSa-Wit eep e Q-eec o th ot ers,- en t "entitle oss t in i heiee re r t eaend h relation of elements which ;are exemplified-in t the .iel win detailed di closu t scope Qofithe application of whichwill be indicatedin =:;the,,clai n s. i Fora fuller understanding of the nature and 1 40, jects oi the invent'on referenceshould be had to the following detarled description takenzin con- ???Qfl c p t e tcqm enrine Q WW in New 1 v r a l is a plan view of a pre-formed and pre- ,welted outsole treated in accordance-with one f orm of the present invention;

'Fig. 2 is a longitudinal sectional View taken along/line 2--2 of Fig. 1; and

Fig; 3 is a fragmentary transverse sectional viewItaken across vthe'forepart of .a lasted welted sho constructed and treated in accordance. with the present invention. The principles of this invention are generally e ee le e hem ee eeter 9 i etw e Wh at e l t ee is, 1 1 23 9? enteel w adi centcoatings such as pyroxylin or like cement=in ,thecourse of manufacture or in thefinished'shoe.

Thus, in Fig. 1, there is shown an outsole "l0 having .a welt llvstitched thereto by'means-pf stitching l2. Such a pre-formed and-pre welted outsole issometimes used, for example, inmaking ,mens sport footw,ear, and it iSBldEvDtEd tQbG ultimately attached to the lasted uppervvhile leaving, a wide extension edgewhich exposes the stitching I2 to view.

For ornamental purposessuch stitching is generally made of white or lightly colored thread which gives a color contrast with the leather used in the welt. With suchlightly colored threads, considerable difiiculty is encounteredin presenting them in a clean unsoiled condition in the ultimately finished shoe.

1 In accordance with the present invention such 7 stitching I2 is not only kept cleanduring-passage of, the Work through thefactory, but it is ulti- .-mate1y presented in atpure white condition if white is the light color-desired,which is-not even shaded by the presenceof waxor therlubricant. To this end, the stitching I2 is formed of-wax .free thread which maybe of-linen, cotton, or other acceptable material. 'lhisthread isnot Waxed for lubricating purposes, as isgenerally done in leather sewing operations,-but is, instead, in; a preferred exampla wet, or lubricatedewith 7 liquid pyroxylin cement which, is applied thereto shortly before the stitching operation so, that the thread will-be wet, or, that is to, say,- sufi1cien tly moist to enable the pyroxylin coatingtol-actfas a lubricant, during stitching.

The area in the vicinity of thesepyroxylin-cement coated stitches is now brushedover with; a coating ,of vpyroxylin cement, designated, 3', which acts as a protective covering for-thestitching during passage of the work through the shoe tactory. In viewof the use of thiscoating as a protection, it is important that the stitchingbe wax- -freetas described, since wax, interferesv with or repels suchcement and. is liable to preventthe 4 forming of aneffective coating.

At this stage the stitched area ofwthe shoe has ,a;protective coating of. cement which is unitary br 95. a so e tht -lub i ati -seat n of cement occurring on the .exposedportions; of the tch ng a W h 1 9 i com te -,:Q. time ,whenitjsdesired to free thestithinglZ 4 from its, protective coating, a; suitable solvent is brushed over or otherwise; applied to the coati ng i n th p s v p rti n tth est taes J fitmen e v ei ei -a i d z ena l s l coating to evaporate or be rubbed entirely away. The solvent also removes the pyroxylin lubricant from the exposed portions of the stitching, leaving them in a natural brilliant white or uncolored condition.

While pyroxylin cement comprises a preferred or highly satisfactory substance for use as the thread lubricant and coating material, it is contemplated that stitches may thus be protected and later exposedto view through use of other suitable lubricants, so long as they are soluble, liquid, and compatible with, i. e. non-repellant to, the coating material. Various coating materials likewise may be employed, which should preferably be soluble, together with the lubricant by means of some common solvent, although this is not strictly essential. The coating material may differ from the lubricant Within these desired limits, or the same substance may be used for lubricant and coating as in the preferred example given. Examples of suitable lubricating and/or coating materials are cellulose esters and ethers such as cellulose nitrates (including the preferred pyroxylin cement), cellulose acetate, the methyl, ethyl, 'etc., ethers and the like. Viscose or plain cellulose in a suitable solvent might also be used for lubricating and/or coating, as well as glues, especially animal glues. It is believed that all of these materials are compatible in the sense that any one may be used as a thread lubricant and any other as a stitch contacting coating with good results and without any mutual repulsion.

Suitable solvents for the above mentioned lubricating and coating materials will readily occur to those skilled in the art; acetone is mentioned as one such solvent which is generally useful with the named cellulose compounds as well as others.

While the invention has thus far been described in connection with a pre-welted outsole, it will be clear that it is applicable generally to shoe parts wherever stitching is intended to be protected against soiling and also wherever lubricated stitching is intended to contact a cement coating.

In Fig. 3, a further and highly useful application of the invention is indicated. Here, a welt shoe is made up by providing an insole I l having the usual insole lip or rib l to which an upper l6 and a welt I! are attached by stitching designated H2. This stitching is like that described in the first form in that it is made of wax-free linen or cotton threads which are lubricated with pyroxylin cement, or other suitable cement of the kinds described above, just prior to the inseam stitching operation so that the applied cement is still wet enough to lubricate during sewing. When thus lubricated, these threads may, if desired, be made thinner than usual, say of five strand linen instead of seven strand, to permit closer inseam trimming. After the inseam is sewed, the cement lubricant is allowed to set, and the inseam is thereafter trimmed. The use of pyroxylin or like cement as a lubricant is doubly advantageous in that it not only is superior to wax because of its compatibility with the cement later used to join the outsole to the welt, but it permits an extremely close trim at the inseam because the thread also is strengthened by its cement coating, and forms a strong, tight seam wherein every stitch is firmly anchored in place. It is of further advantage in cemented welt shoes because it enables the welt and inseam portions to be roughed prior to cementing with reduced fear of weakening the joint at the inseam. That is, the shoe is next reduced at the inseam and roughed at the welt and inseam and these operations may be carried quite close to the stitching H2 since even if a strand or two or even a whole stitch of the latter is broken, the thread still will not pull out or run because it is firmly anchored in the shoe by means of its cement lubricating coating which has by this time set.

After the trimming and before theroughing operation, a suitable filler I8 is applied, and the required amount of this is much less than usual because of the closeness of inseam trim available with the pyroxylin lubricated inseam stitches.

Next, an outsole l 9 is afiixed to the welt l1 and .the inseam portion of the upper by means of a cement coating l l3which is applied between these shoe parts. By virtue of the use of a pyroxylin or like cement lubricant, the bond between the outsole and upper is much stronger than could be obtained with ordinary wax lubricated thread since, as explained above, wax is incompatible with and repels a cement. Also, the number of operations previously needed with conventional waxed thread is reduced, since heretofore the wax had to be stripped from the exposed inseam stitching whenever it was desired to cement in the vicinity. The wax, too, would get on the hands of operators and thence to the sole and welting, where it acted to prevent formation of an effective cemented bond. All such difliculties are overcome by the present invention, and in addition, a stronger, better and more closely trimmed welted shoe is provided.

The cement coating H3 preferably comprises those among the above recited examples of materials which have sufliciently strong cementitious properties, pyroxylin or other cellulose derivative cements being preferred for this purpose. The associated lubricant may comprise any of the herein mentioned examples or their like, all of which are compatible with any sole afiixing' cement selected from among those described. The lubricant preferably should be cementitious when used at the inseam and like places, to secure the advantages of a firmer sewed bond wherein every stitch is anchored in the leather.

It will be seen that there has been provided an invention which is well suited to fulfil its intended functions. Since certain changes in carrying out the above method, and certain modifications in the article which embody the invention may be made without departing from its scope, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted-as illustrative be said to fall therebetween.

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

invention which, as a matter of language, might I. A method of protecting shoe stitching from soiling, which comprises, providing a wax-free thread, lubricating said thread with a liquid capable of forming a soluble coating, sewing shoe parts together with said thread While the lubricant is still wet, applying a soluble coating over exposed portions of said stitching, using said shoe" 7 parts to make a shoe and, after the shoe is completed, dissolving. said coating and the lubricant in the exposed portions of said stitching.

2. A method of protecting shoe stitching from soiling, which comprises,providing a wax-free thread, lubricating said thread with a liquid cement comprising a cellulose derivative, sewing shoe parts together with said thread while the cement lubricant is still wet, and applying a coating of such cement over exposed portions of said stitching.

3. A method of protecting shoe stitching from soiling, which comprises, providing a wax-free thread, lubricating said thread with a liquid cement comprising a cellulose derivative, sewing shoe parts together with said thread while the cement lubricant is still wet, applying a coating of such cement over exposed portions of said stitching, using said shoe parts to make a shoe and, after the shoe is completed, dissolving said coating and the lubricant in the exposed portions of said stitching.

4. A method of protecting shoe stitching from soiling, which comprises, providing a wax-free thread, lubricating said thread with a liquid pyroxylin cement, sewing shoe parts together with said thread while the cement lubricant is still wet, applying a coating of pyroxylin cement over exposed portions of said stitching, using said shoe parts to make a shoe and, after the shoe is completed, dissolving said coating and the lubricant in the exposed portions of said stitching.

' FRIEDRICH HOLLAND.

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