US2444931A - Box toe stiffener - Google Patents

Description

July 13 1948 w. H. HEAToN Erm. Y 2,444,931

BOX TOE STIFFENER Filed April 24, 1947 my. ,ze

Patented July 13, 194s4 nox 'ros srmFENEa .Waiter Il. Heaton, Franklin, Masa., and William J. Vaccaro, Springvale, Maine, assigner: to

Beckwith Manufacturing Company, Dover N. ll., a corporation of New Hampshire Application April 24, A194'1', Serial No.l '143,060

' (chas-71) 4 Claims. l

'Ihis invention' comprises a new and improved box toe stiilener of the thermoplastic type and is to other parts of the upper during the shoe-making process.

It is customary in' bed-lasting shoes having. nat insoles, as distinguished from the ribbed insoles of welt shoes, for the operator first to wipe the assembled plies of the toe portion of the upper over the insole once or twice to preformthe toe of the shoe, Then he retractsl the wipers and turns upwardly the plies of the upper with his thumb, separating the box toe doubler and iining--all three oi' these plies being in laminar engagement at this stage of the shoemaking process. He then trims away a portion of this material at the toe end of the upper so that upon resumingV toe wiping there will be less bulk of upper material upon the toe end of the insole. In such conventional shoes as are fitted with a doubler,

which is a fabriclply located between the box toe and the leather, this practice is easily carried out and oiiers the operator no problem since the doubler prevents adhesion of the box toe to the flesh surface of the outer or leatherintegument of the upper. However, since skeleton constructions are popular, many shoes are today made without doublers and in that case the box toe lies in direct contact with the ilesh face of the upper leather. Under these conditions the box toe adheres to the upper after the primary wiping by the' operator and separation for the toe trimming I'I'he present invention may be usefully embodied in any box toe stiire'ner which has the property of being rendered` pliable at ja moderate heat, which sets readily after being molded and is suiiiciently stiil! and resilient to maintain the original shape of the shoe under all usual' conditions of heat and moisture in wear.

By way of example the stifiener may comprise a body of iibrous material, such as wool felt, or its equivalent, which may be readily saturated or impregnated with the stiil'ening compound. 'I'hat compound may comprise resin, wax, asphaitum. rubber or other hydrocarbon blended to have a softening point which will permit the impregnated body to become soft, adhesive an easily molded at a moderate temperature-say 160 to 2109 F.

After the sheet is impregnated with the stillening compound and has cooled and hardened, it is step becomes difficult, causing loss of time, imy perfect worir and annoyance to the operator.

The present invention contemplates a thermoplastic box toe stiener coated or otherwise provided with an adhesive retarding or preventing material throughout its tip area; for example, in a segment at the tip of the stiiiener approximately t" in width at its widest point. The uncoat-L ed or untreated area of thebox toe stiflener will remain adhesive in the lasting operation, but the treated tip portion will not adhere to the upper leather during the primary wiping and consequently the operator can easily and expediently prepare the toe for trimming.

These and other features of our invention will be best understood Vand appreciated from the following description of a preferred embodiment thereof, selected forv purposes oi illustration and shown in the accompanying'drawing. in which- Fig. 1 is a plan view oi a stiiielier. and'- v n?? 2 is a sectional view on the line 2--2 of cut into blanks of the desired shapes and sizes, and ii' ,desired one or more edges may be skived or otherwise reduced in thickness.

The blank i0 of Fig. 1 is of the character described and of a shape widely used in shoe manufacturing at the present time. Its forward edge is convex in outline and its rear edge has a cornpound curvature including a concave central portion. The thermoplastic impregnating compound, in this illustrative case. may comprise:

Pounds Rosin 4,400 Copal 700 Hydrated lime y 115 Hard wax, montan or candelilia 1,000

China-wood nii 150 An alternative formula for suitable thermo# plastic compound is as follows:

- Having prepared the stiiiener blank, which as a whole is thermoplastic and has latent adhesive properties, we now proceed to coat a limited por- 1 tion of the tip area, for example the segment il.

a0 nently non-adhesive.

with a heat resistant compound which is perma- 'Ihis may be readily ef iected by dipping the toe end of each blank into. or brushing it with. a solution of silicate of soda and a `iilier or extender of inert powder. One suitable compound may be made by mixing ,5 gals.

u of silicate o! soda with lbs. ofvnne clay.

other solution that will, deposit upon the ilbrous blank a permanently non-adhesive iilm. The non-adhesive film may be applied to one or to both surfaces oi the stifl'ener, it being essential only that the surface deposited next to the leather integument of the upper be thus coated.

The stiilener of our invention is employed exactly as stlil'eners heretofore used in the conventional manufacture of shoes. When the toe end of the upper is heated preparatory to the pullingover or toe lasting operations, the blank as a whole becomes plastic and easily moldable. It also becomes adhesive throughout its entire area, except for the coated tip portion which has been protected by the permanently non-adhesive compound and which, therefore, exhibits no tendency to adhere to any portion of the upper.

Having thus disclosed our invention and described in detail a preferred embodiment thereof, we claim as new and desire to secure by Letters Patent:

1. A box toe stiiener comprising a felt body saturated with a thermoplastic compound of the shoe.

resin, wax and hydrocarbons, and being thereby rendered thermoplastic and adhesive as a whole, and having a curved tip portion of its area coated with a non-adhesive compound of silicate of soda and ilnely divided clay.

2. A box toe stiifener comprising a fibrous body impregnated throughout with a thermoplastic compound Lhaving latent adhesive properties, and having a heat-resistant, permanently non-adhesive coating as both faces of a segment including the tip of the stiffener, whereby the stiffener as a whole may be molded while hot and at the same time present adjacent adhesive and non-adhesive surface areas.

3. A box toe stiiener comprising a normally hard brous body impregnated throughout with a resinous thermoplastic compound having latent adhesive properties, and having a tip portion of convex outline which is coated with a compound of silicate of soda and an inert powder, the stiftener being moldable as a whole at a moderate temperature and adhesi-ve only in its uncoated area.

4. A box toe stiiener comprising a normally hard and stii brous body impregnated with a resinous thermoplastic compound having latent adhesive properties, and having on one surface of its tip portion a permanently non-adhesive coating, whereby the stiiener may be molded at a moderate temperature in box toe shape without adhering to the leather of the upper at the tip of WALTER H. HEATON. WILLIAM J. VACCARO.

Images