US2114993A - Shoe and method of manufacturing the same - Google Patents

Description

April 26, 1938. F1 BRAND-r 2,114,993

SHOE AND METHOD OF MANUFACTURING THE SAME Filed Oct. 29, 1935 2 Sheets-Sheet 1 April 26, 1938; F BRANDT 2,114,993

SHOE AND METHOD OF MANUFACTURING THE SAME Filed 001;. 29, 1935 2 Sheets-Sheet 2 wvfwwar Patented Apr. 26, 1938- OFFICE SHOE; AND METHOD OF MANUFACTURING THE SAME Francis L. Brandt, Wakefield, Mass., assignor to United Shoe cry Corporation, Paterson,

N. 3., a corporation of New Jersey Application October 29; 1935, Serial No. 47,284

18 Claims. (01. 12-142) This invention relates to shoemaking and is illustrated as embodied in shoes the heels of which are attached with adhesives, and with reference to methods of attaching the heels to the shoes.

It is common practice to attach wood heels to shoes by nails or screws which are driven from the inside of the shoe after the last has been pulled. While various finishing operations such as securing covering flaps to the breasts of the heels, edge trimming, edge setting and scouring,

are being performed, the heel should form an integral part of the shoe, the shoe at this time preferably being on the last in order to maintain 15 the shape of the shoe and to facilitate carrying out the above operations. In order to avoid having to pull the last for the purpose'of securing the heel to the shoe by inside nailing and then having to reinsert the last in the shoe, it is customary in the manufacture of the better grades of shoes to secure the heel temporarily by glue to the shoe preparatory to performing the various finishing operations. lifter the shoe has been substantially completed and the last has been pulled the heel is permanently secured to the shoe by nails or screws.

In order to retain as much as possible the pressure of the heel against the heel seat of the shoe for the purpose of preventing the shoe materials from springing back while the finishing operations are being performed and to insure that the heel seat shall set in permanently molded position, it is often the practice to use a temporary attaching screw inserted as disclosed in United States Letters Patent No. 1,502,014, grant; ed July 22, 1924 on an application filed in the name of Frederic E. Bertrand.

In attaching the heel to the shoe temporarily by glue the heel is clamped with considerable pressure against the heel seat of the shoe upon the last for a period sufflcient to allow the glue to dry. The heels may be temporarily attached to the shoes by the use of a heel-attaching machine of the turret type, for example as disclosed in Letters Patent of the United States No. 1.376.539, granted May 3, 1921 on an application filed in the names of Isabelle Henne and John L. Free, in which heels are pressed upon the shoes for a substantial period thereby permitting the glue to dry before the shoes are removed from the machine and go forward for subsequent. operations.

The results obtained when using the temporary attaching screw have been generally satisfactory. It has been found, however, that when glue alone is relied upon to attach the heels temporarily to the shoes some of therheels become detached before the heel-attaching nails or permanent screws are inserted. Even though the heels do not become detached, they frequently spring away from their molded positions upon the heel seats of the 5 shoes. Such a condition is unsatisfactory, particularly in the case of Louis heel work in which the. heel has a covering flap secured to its breast and is seldom restored to its original position upon the shoe at the time of the permanent attaching 1o operation, with the result that a wrinkle is formed in the flap in the vicinity of the heel-breast line of the shoe.

With the above and other considerations in view and in accordance with a feature of the pres- 15 ent invention, I propose toprovide a shoe and a heel which is to be attached to the shoe with anchoring means, and to interpose a mass of hot thermoplastic material between the heel and the shoe. The heel is then pressed against the heel seat of the shoe to force the thermoplastic material into interlocking engagement with said anchorlng means, pressure of the heel against the shoe being maintained until the thermoplastic material cools and hardens.

When a quantity of thermoplastic adhesive is used to attach the heel to the shoe, the time dwell during which the heel need be held against the heel seat with molding pressure is reduced materially and there is little danger of the heel becoming loose as the operator performs the various finishing operations. When the last has been removed from the shoe the thermoplastic material may, if desired, be supplemented by nails or screws. Furthermore, by utilizing an undercut or reentrant cavity in the attaching face of the heel and a similar cavity or other appropriate anchoring means in the heel-seat portion of the shoe, the thermoplastic material may be forced to take 40 the form of a' rivet which, after it has set, has such a strength and permanence and such an interlocking engagement with the shoe and heel as will enable it to serve as the entire heelattaching means. The thermoplastic material, 45

- preferably in the form of a plug, is insertedin one of the undercut cavities and the heel is. forced with molding pressure against the heel seat while the plug is in moldable condition; the heel being then clamped against the heel seat 50 until the heel seat has become permanently molded and until. the thermoplastic material has set. The plug should be of a size to fill both the cavities as well as to fill, so far as practicable, the

space included between the attaching face of the 55 heel and the heel seat of the shoe, as well as all the insole 34, (Fig. 3) of the shoe. During the interstices or voids in the latter. With the above arrangement the heel is effectively secured to the shoe upper by a large'rivet of hardened material which may be said to be clenched to the heel and to the heel seat and its respective ends and which is of suflicient strength to'serve as the entire heel-attaching means.

In order to provide an exceptionally strong and durable form-retaining heel end structure for the shoe a further feature of the invention resides in the provision of an insole having a. fibre reenforcement attached thereto extending to the margin of the heel seat, which reenforcement has a projecting portion which may be embedded in the hardened mass of thermoplastic cement in a. manner to hold the overlasted margin of the shoe upper tightly clamped between the reenforcement and the rim of the heel. It is further contemplated that a shank stiffener be locked in the mass of thermoplastic material and this may be done either independently of the above-mentioned reenforcement or by combining the shank stiffener and the reenforcement as a single unit thereby obtaining in a maximum degree the qualities of strength and rigidity which are so desirable in the heel portion of a shoe.

The above and other features of the invention in both its method and shoe structure aspects will be better understood and appreciated from reading the following detailed description there- I of in connection with the accompanying drawings, in which Fig. 1 is a perspective view of a shoe upon a last, the heel-seat portion of the sole of the shoe having been fitted for the reception of a Louis heel;

Fig. 2 shows in perspective a heel with a mass of thermoplastic adhesive applied to its attaching face, and a tool for applying the adhesive to the heel;

Fig. 3 is a perspective view, partly in section, showing the heel of Fig. 2 after it has been forced with moldingpressure against the heel seat of the shoe ofFlg. 1; I

Fig. 4 is a perspective view of a sole having a fibre reenforcement secured thereto;

Fig. 5 shows a covered Cuban heel having an undercut cavity in its attaching face;

Fig. 6 is a perspective view, partly in section,

of the heel end of a shoe having a short outsole,

Fig. 9 is a transverse section taken through the heel end of the shoe after the heel has been permanently attached to the shoe.

In the manufacture of the shoe 22, which is illustrated asmounted one last 24, a pair 01' I heel-breast receiving shoulders. l8 (Fig. 1) have been formed upon the sale 20 and the heel-seat portion of the sole has been reduced thereby providing a tongue 26 of suitable shape'to be included within the attaching face 28v of a wood heel 30, tacks 32 being employed, in accordance with usual practice, to secure the tongue 26 to heel-attaching operation the rim 36 of the attaching face 28 of the heel 30 is forced with molding pressure against the overlasted counter portion 38 of the shoeupper, the rim forming a shallow groove 40 (Fig. 3) in the previously somewhat rounded margin 42 (Fig. 1) of the heel seat of the shoe.

In order to insure that the heel 30 may be effectively secured to the shoe 22 while various finishing operations are being performed upon the shoe and until the last 24 has been pulled and the heel has been nailed or otherwise permanently attached to the shoe, I propose to interpose a substantial quantity of thermoplastic adhesive 44 between the heel 30 and the heel seat of the shoe 22, the heel then being forced with moldingpressure against the heel seat of the shoe and being clamped in molding relation with the heel seat for a period of sufficient duration to insure thesetting of the adhesive.

The thermoplastic adhesive 44 may conveniently be applied to the attaching face 28 of the heel 30 by a plate 46 of suitable shape. Although the thermoplastic adhesive 44 is illustrated with- The heel 30 may be effectively forced against the heel seat of the shoe 22 mounted upon a support 48, by a tread clamp 50 and a back clamp 52 constructed and arranged to engage a thick leather apron 54 which covers the rear face of the heel, the shoe being positioned lengthwise relatively to the clamps by a back gage 56. A machine which comprises the above-mentioned elements and which may be advantageously used for clamping heels to shoes, is disclosed in United States Letters Patent No. 2,076,537, granted April 13, 1937 on an application filed in the name of Bazzoni, a covering flap 51, in accordance with a preferred practice, being applied to the breast of the heel by the machine while the heel is held under molding pressure against the shoe. When heels are temporarily attached to shoes by thermoplastic adhesive as above described there is little, if any, trouble experienced due to the heels becoming loose between temporary and permanent heel-attaching operations.

While it may be impracticable to attempt to fill absolutely all the voids or interstices included between the attaching face of the heel and the heel seat of the shoe, since it is desirable to insure that the thermoplastic adhesive 44 shall not .seep from between the rim 36 of the heel 30 and the counter portion of the shoe, nevertheless by using reasonable care and an appropriate quantity of thermoplastic material these spaces may be substantially filled. It will be understood that the heel-seat portions of the soles may be reduced to various shapes, the amount of thermoplastic adhesive used varying .in accordance with the shape of the reduced heel seat.

In order permanently to secure heels to shoes by thermoplastic adhesive without the aid of nails or screws, the procedure illustrated in Figs.

4 to 9 may be utilized. In those figures a shoe 58 is provided with a Cuban heel 80 which is secured to the shoe by a rivet 62 of hardened thermoplastic adhesive, best shown in Fig. 9. The insole 64 (Fig. 4) of the shoe 58 has a fibre'reenforcement 66 adheslvely or otherwise secured to it, the reenforcement having a channel 68 for receiving a shank stifl'ener I and a hollow frustoconical projecting portion I2 which is located at the rear end of the channel and maybe described as being funnel-shaped with its smaller end'projecting from the insole. The attaching face 14 (Fig. 5) of the heel 60 is provided with an undercut conical cavity 16. After the shoe 58 has been lasted the shank stiffener 10 is tacked or otherwise secured to the insole, the stifiener being of suitable shape to fit within the channel 68 of the fibre reeniorcement 68 and having a' bent rear end 18 which extends into the hollow conical projecting portion I2 of the fibre reenforcement 66. A short outsole 80 provided with a heel-breast receiving shoulder 82 (Figs. 6 and 7) is then attached to the shoe 58. The rivet 62 of thermoplastic adhesive is formed from a, lump or plug 84 which, after being heated to the proper moldable temperature, is inserted within the cavity 16 (Fig. '7) of the heel 60. The shoe 58 is then mounted upon the support, 48 and the heel 60 is forced, for example by the use of the heel-attaching machine above referred to, against the heel seat of the shoe which may be described as having a reentrant or undercut cavity 86 (Fig. 6). The lump or plug 84 of thermoplastic adhesive may be inserted in the cavity 86 (Fig. 8) of the heel instead of being inserted in the cavity 16 of the heel. The hardened rivet 62 of thermoplastic adhesive fills the undercut or reentrant cavities I6, 86 and also fills a considerable portion, preferably all or substantially all, of the space between the heel seat of the shoe and the attaching face of the heel.

The heel is clamped in molded relation with the shoe for a period suflicient to insure the hardening of the thermoplastic material, the heel thereafter being held securely in its molded position upon the shoe by the rivet 62 of hardened thermoplastic adhesive which may be said to be clenched at opposite ends within the undercut cavities I6, 86. In the illustrated construction the bent rear end I8 of the shank stiffener I0 is preferably embodied within the rivet 62 and in combination with the fibre reenforcement 66 secures the heel to the rear end of the shoe upper and provides an exceptionally strong and durable form-retaining heel end structure for the shoe. N

A thermoplastic adhesive which may be eflectively used for attaching heels to shoes is disclosed in United States Letters Patent No. 1,945,803, granted February 6, 1934 on an application filed in the name of Myron E. Delaney.

Ha'ving described the invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. The method of attaching heels to shoes which comprises providing a. shoe upper which has a reentrant cavity in its heel seat, providing a heel having a reentrant cavity in its attaching face, interposing a quantity of moldable thermo-- plastic adhesive between said heel seat and said attaching face, clamping the heel under heavy molding pressure against the heel seat while the adhesive is in a moldable condition thereby causing the same to fill said cavities as well as to fill voids included betweenthe attaching face of the heel and the heel seat, and maintaining the heel clamped to the heel seat for a period sufficient to insure the setting of the adhesive.

2. The method of attaching a heel to a shoe 1 which comprises providing recesses in the heel and the shoe, interposing a mass of self-hardening plastic material in a plastic condition between the heel and the shoe, pressing the heel against the heel seat of the shoe to force the plastic material into said recesses, and permitting the plastic material to harden.

3 The method of attaching a heel to a shoe which comprises providing cavities in the heel and the shoe, interposing a mass of hot thermoplastic material between the heel and the shoe, pressing the heel upon the shoe to force the thermoplastic material into said cavities, and permitting said material to cool and harden.

4. The method of attaching a heel to a shoe which comprises providing the heel and the shoe with anchoring means, interposing a mass of hot thermoplastic material between the heel and the shoe, pressing the heel upon the. shoe to force the thermoplastic material into interlocking engageing element having a projecting portion, lasting an upper and counter over the'insole and securing them thereto, attaching an outsole to the shoe leaving the projecting portion of said reen forcing element exposed, providing a heel with an anchoring means, interposing a mass of plastic material between the heel and the heel seat of the shoe, pressing the heel against said heel seat to force the plastic material into interlocking engagement with said anchoring means and the projecting portion of said reenforcing element, and permitting said plastic material to harden.

6. The method of securing a heel having an undercut cavity in its attaching face to a shoe provided with a heel seat having an undercut cavity, comprising inserting a plug of moldable thermoplastic adhesive into one of said cavities, forcing the heel against the heel seat with molding pressure while the plug is moldable to cause said adhesive to fill said cavities and to fill at least a substantial portion of the voids included between said heel seat and said attaching face, and maintaining pressure of the heel against the heel seat until the adhesive has set thereby permanently securing the heel to the shoe.

7.- A shoe the heel and heel seat of which have undercut cavities filled with a hardened mass of plastic material which is ofsufiicient strength to secure the heel permanently to the shoe.

8. A shoe the heel-seat portion of which has an undercut cavity, a heel engaging said heelseat portion and also having an undercut cavity,

said heel being secured to the shoe by a rivet consisting oi a hardened mass of thermoplastic material engaged in and substantially filling both of said cavities.

9. A shoe having a heel seat provided with a cavity, a shank stiflener, and a heel engaging said heel seat andhaving a cavity in its attaching face, the heel being secured to the heel seat by a hardened mass of plastic material interengaging the cavities in the heel and the heel seat and permanently embedding and locking a portion of the stiflener.

10. A shoe having a heel seat containing a reentrant cavity, a heel having a reentrant cavity in its attaching face, a mass of hardened plastic the heel to the shoe, and a shank stiil'ener the rear end of which extends into the cavity in the heel seat and is embedded andlocked in said material.

11. A shoe the heel end of which comprises an insole, a rigid reenforcing member attached to the lower face of the heel portion of the insole, said member extending substantially to the margin of the heel seat of the shoe and having a hole in its central portion to provide a cavity the bottom' of which is formed by the insole, a heel having an attaching face provided with a cavity, a shoe upper having an overlasted margin clamped between the reenforcing member and the heel, anda massof hardened plastic material interlocked within said cavities and serving to maintain the edge of the heel tightly against the heel seat.

12. A shoe having a heel provided with a cavity in its attaching face, an insole, a reenforcing member which is secured to the lower face of the insole and has an anchoring portion extending toward the heel, and a shank stiffener the rear end of which extends toward the heel, all of the above parts being secured together by a mass of hard thermoplastic material.

13. A shoe having an insole, a fibre reenforcement secured to the lower face of the insole, said reenforcement having a hollow, frusto-conical portion the smaller end of which projects from the insole and a heel having an-undercut cavity in its attaching face, all of the parts being secured together by a hardened mass of plastic material substantially filling the hollow frustoconical portion of the reenforcement and the undercut cavity of the heel.

14. A shoe having an insole, a heel the attacha ing face of which is provided with an undercut recess, a fibre reenforcement secured to the lower face of the insole, said reenforcem'ent having a funnel-shaped portion the smaller end of which projects toward the heel, and a short outsole, all of said parts being engaged and securedtogether by a hardened mass of plastic material.

15. A shoe having a heel provided with an undercut cavity in its attaching face, an insole, V a reenforcing member secured to the lower face of-the insole and having a funnel-shaped projection the smaller end of which extends toward the heel, a shank stiflener the rear end of which extends toward theheel and into the funnelshaped projection, all of theabove parts being engaged and secured together by a hard mass of thermoplastic material.

16. A step product consisting of a shoe ready to receive a heel, said shoe being provided with a cavity which is included within the heel-seat of the shoe and is limited in depth by the insole of the shoe, and a mass of thermoplastic material in said cavity.

17. A step product consisting of a shoe ready to receive a heel, said shoe being provided with an undercut cavity which is included within the heel seat of the shoe andis limited in depth by the insole of the shoe, and a mass of thermoplastic material in said cavity.

18. An insole for use in the manufacture of shoes having a relatively rigid reenforcement se-,

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