US2280099A - Shoe heel and method of making same - Google Patents

Description

Patented Apr. 21, 1942 A I snoa HEELAND Horace A. Sheesley, Portland, Maine, asslgnor to .lnflde Products Oorpo a corporation of Maine No Application Serial No. 151,450

Claims.

invention relates to shoe heels and method of making same. 1" I 1 Shoe heels have heretofore been made of such materials as leather, rubber or wood. Women's high heels are generally made of wood, which has generally proven more satisfactory than an all leather or all rubber heel. Wood heels, however, must be made from selected wood which has been thoroughly dried andis free from chinks and cracks. Due to the spindle-like con-. structlon of womens high heels as now designed. the wood heel is subjected to severe strains and the heels often break off in use. Wood heels are also hard on the feet of the wearer since wood has little or no resiliency or spring and oftentimes the heels come off from a shoe sole due to the loosening of the nails or screws holding the same in place. The wood heel also has to be lacquered and treated to give it the desired shade.

Leather heels are usually stronger than wood heels but are expensive to manufacture, possess a small degree of resiliency and are also heavy on the feet. Rubber heels are only adapted for low heeled shoes since the rubber composition used does not possess sufllcient stillness and rigidity to be satisfactorily used on a high heel. Rubber heels are also heavy on the feet and relatively expensive to manufacture.

In accordance with this invention, heels for mens, womens and children's shoes and slippers are made from a fibrous composition moldable into any desired form or size. The composition isformed from a wood base, such as wood flour, or wood flour mixed with a fibrous ingredient such as wood pulp. This base material is quite inexpensive and is light in weight. The wood flour with or without pulpfibers is held together in a strong composite'mass by means of a binder which preferably comprises a rubberous material such as latex, which may be mixed with animal glue and certain curative and hardening agents, such as formaldehyde and an alcohol, so used as to harden the latex and glue in situ. After thoroughly mixing the wood flour and fibers with a binder, the mixed composition is placed into a .mold having the desired heel-forming cavity :therein and a substantial pressure applied to the mold so as to compress the composition into a compact mass. The compressed composition is then removed from themold and the volatile constituents removed ,in a suitable drier.

tages over the wood, leather and rubber heels ration, Portland, Maine,

July 1 19:1.

(Cl. se -w from the composition above described are lighter in weight and lower in cost than either wood. rubber or leather heels and possess a wearing quality and the desired resiliency which is superior than either wood leather or rubber heels,

' as heretofore manufactured. My improved heels are stronger and tougher than wood heels and will not crack or break off in use. This is especially important in the manufacture of women's high heels in current fashion having a spindlelike shape. My improved heel will also hold nails and screws better than wood or rubber heels due to the fact that the nails or screws become enveloped in the adhesive binder forming one of the materials of which the heel composition is made. My improved heel composition can be colored to resemble natural leather by placing a suitable coloring dye in the mixed batch, or

any desired color can be given to the composition either afteror prior to the molding thereof. My heel is waterproof and is thus not affected by moisture and does not increase in weight by contact with moisture as in the case of leather or wood heels. These marked advantages are clearly recognized by those skilled in the art.

Other objects and advantages of this invention will become apparent as the disclosure proceeds. Y

The invention also consists in forming a product having the general characteristics, the new and useful applications,- and the several original features of utility hereinafter set forth and claimed.

In accordance with the present invention, a quantity of wood flour made from pulverizing wood chips, sawdust or wood waste is provided. Such wood flour is a readily available by-product of lumber manufacture. In certain instances it may be desirable to mix with the wood flour a quantity of finely divided flufly fibrous material such as wood pulp or other animal or vegetable fibers so as to produce a composite without the fibrous mixture into a compact mass heretofore used. My improved heels formed preferably includes latex or similar rubberous material. I have found that a high grade glue may be added to the' rubberous liquid latex ingredient along with a small amount of ammonia and formaldehyde and a highly volatile organic liquid. Animal glue, such as blood of albumin type, is preferable although fish glues, hide glues, egg albumin glues or other fat-free animal glues may be used. Casein glue may be used, but it is not usually recommended due to the fact that it has a tendency to decompose in warm moist weather. The compound should be free from zinc oxide and other materials which unfavorably affect the desired binding action of the latex or glue constituent.

The volatile organic liquids preferably used contain alcohol as the principal constituent. A liquid should be selected which is highly volatile, which will readily escape from the fibers and which will preferably aid in removing the less volatile liquid materials, such as water, from the composition during manufacture. A very satisfactory volatile liquid has been made from approximately 85% to 90% ethyl alcohol and approximately 10% of a mixture of methyl alcohol, acetone, ethyl acetate and aviation gasoline.

The cheaper alcohols, such as wood alcohol or grain alcohol, preferably 170% proof and upwards, can be used.

A small amount of liquid ammonia is added to stabilize the latex in solution and prevent a premature precipitation of the latex solids. A small amount of formaldehyde may also be added to assist in tanning the glue and prevent odors from the resultant product.

By way of example, the following formula has been found satisfactory for the purpose of this invention. To 8 /2 lbs. of liquid latex of good commercial grade is added 6 lbs. of blood albumin blood albumin and 5 lbs. of water. The quantities above referred to are representative and, of course, will vary within fairly wide limits since liquid latex from Various sources may vary in amount of solid constituents and various sources of blood glue also vary in water-absorptive qualities. A liquid latex containing approximately 40% rubber solids provides a desirable material. Suflicient water should be added to the solid blood albumin to reduce the same to a soft but non-flowing gel.

For blending purposes approximately lb. to 2 lbs. of a readily volatile liquid comprising a major portion of ethyl alcohol is added. The escap of the liquid constituents of the binder from the fibers may be facilitated by increasing the quantity of alcohol added. The proportion of aqueous ammonia which is addedvwill depend upon the amount of ammonia contained in the commercial liquid latex. As a general rule, however, most commercial grades of latex will require the addition of from /2 lb. to 2 lbs. of liquid ammonia to every 8 /2 lbs. of latex. Approximately /2 oz. of formaldehyde added to the above constituents is sufficient to remove any odors from the material and exert the desired tanning and hardening action on the blood albumin glue. A binder material containing approximately the above proportion of ingredients is liquid and free flowing and can be readily incorporated into the fibrous mass to homogeneously coat the fibers and bind them into a solid mass.

In summarizing the effective formula above referred to, the binder,may contain approximately 18% to 22% rubber solids from latex, 4% to 7% of blood albumin, giving a solid constituent of approximately 25%, a liquid constituent of 70% to 74%, and a gaseous constituent of 1% to 4%. The normally liquid and gaseous constituents would comprise approximately 60% to 65% water,

6% to 8% ethyl alcohol (which might also contain approximately 1% or less of methyl alcohol), ethyl acetate and aviation gasoline, together with approximately of 1% of formaldehyde and from 1% to 3% ammonia.

The above formula is given by way of example only. The amount of liquid latex used should be sufllcient to thoroughly cement the wood particles and fibers together in a strong composite mass. Sufilcient alcohol should be added to permit thorough mixing of the wood flour base materials with the binder. It has been found by actual experiment, however, that the finished material may possess considerably less than 50% by weight of binder constituent and 50% or more by weight of wood flour and fibrous material.

Commercial latex varies from approximately 25% to 60% in the amount of solid latex constituents. Since the solid constituent is an important component, it is always desirable to test each batch of latex for rubber solids before combining the same into a mixture. Different types of albumin blood glue will also absorb diflerent quantities of water varying from one part dry glue to 4 to 7 parts water, depending upon the source of the albumin, which varies in different animals. Sufliciena water should be added to the dry glue to produce a soft but non-flowing gel.

From 2% to 20% of a highly volatile liquid, such as alcohol, may be used, the percentage varying with the hardening and drying speed desired.

The base constituent, such as the wood flour with or without the additional fibrous material, is placed in a batch mixture or pulp mill, where it is churned by paddles. The latex and aqueous glue solution is preferably added to the base material while being stirred by the paddles in the batch mixer. When the glue and latex have been added, a tanning agent such as formaldehyde and alcohol are added in the general proportions above named. When the material has been thoroughly mixed so that it is a doughlike plastic mass, predetermined quantities of the mixed composition are injected preferably by air pressure into a strong mold having a mold cavity therein which conforms to the shape of the heel to be molded. The molds are preferably associated with a suitable mechanical press provided with a plunger or other ramming device for applying pressure to the composition injected into the mold. Preferably, each heel should be subjected to from 1 to 10 tons pressure, depending upon the size and shape of the heel. The compacting action should be such as to force the binder component to surround each particle of base material so as to form a strong compact mass having the desired hardness and resiliency characteristics.

After the molding operation the compressed heel is placed within a suitable drier. The drier preferably comprises an enclosure, such as a room or tunnel, suitably heated to a temperature of approximately 200 F. to 250 more or less. The greater proportion of the volatile liquid constituents, such as the water and the alcohol, are driven off and evaporated from the compressed composition when subjected to these temperatimes.

To hasten the drying action, the drier interior may be reduced to a partial vacuum by means of vacuum pumps and suitable means, such as condensing apparatus, may be provided to recover the volatile material, such as alcohol, used in the process.

The heels may be given any desired finish. The molded heels may be coated with any of the colcred lacquers applied to wood heels. It has been found that these colored lacquers have great adhesion to my molded heel and the lacquer will not chip off as is often the case with lacquered wood heels. The molding composition itself may be colored the'desired shade by mixing a dye or coloring agent into the batch in the pulp mill as it is being stirred. Any desired finish can be given to the composition.

My improved molded heel is light and comfortable on the foot; it is waterproof and will not take up moisture; it is resilient to abrasive wear and has unusually long wearing qualities; it

holds nails and screws with great tenacity; it is unusually strong and tough in all directions,

and it will not crack off even when molded into spindle-like heels. My improved heels are generally cheaper to manufacture than wood, leather, rubber, or other molded heels now in use,

since .the ingredients which form the composition are inexpensive and the molding and drying geneously mixed with said base material, said binder material consisting of dehydrated latex and animal glue.

2. A molded heel for a womans shoe comprisins, a base material and a binder homogeneously mixed and firmly. compacted, said base material comprising ground wood flour, said binder material comprising-dehydrated unvulcanized latex and animal glue tanned in situ.

3. A molded shoe heel including, a homogeneous base material comprising 50% and upwards of wood flour compressed and interbonded in atough compressed mass of substantially uniform tensile strength in all directions with a binding material comprising the solid residuum of a liquid flowable mixture of latex, animal glue and a tanning agent.

4. A molded shoe heel characterized by lightwas in weight and high strength in all directions comprising, 50% and upwards of a base material comprising highly compressed wood flour, and a operations can be performed automatically at a high rate of speed. The heel has the desired resiliency to make it very comfortable to walk upon and due to its lightness it is especially adapted for women's shoes, slippers and sandals, where lightness and strength are of prime importance.

While certain novel features of the invention have been disclosed and are pointed out in the annexed claims, it will be understood that various omissions, substitutions and changes may be made by those skilled in the art without departing from the spirit of the What is claimed is;

l. A-molded shoe heel characterized by lightnessin weight and high strength in all directions comprising, a major proportion of a base material including compressed wood flour homogeneously mixed with animal vegetable fiber, and a minor proportion of a binder material homoinvention.

binder material for the base material homogene-' ously dispersed therein, said binder material consisting of dehydrated latex and animal glue tanned in situ..

5. A molded high heel for women's shoes. consisting of a homogeneous base material compressed and interbonded in a tough compressed mass of high and uniform strength with-a resilient bonding material, said base material consisting of or more by weight of wood flour and a minor proportion of fibrous material, and said bonding material consisting of coagulated latex' and animal glue tanned in situ and derived from a binding liquidcontaining approximately 25% solids, including dispersed rubber solids and albumin, and approximately nonsolid components including water, alcohol, ethyl acetate, gasoline, formaldehyde and ammonia.

HORACE A. SHEESLEY.