Seamless ski shoes and method of making same

Jan. 9, 1968

V. DRAGO

3,362,091

SEAMLESS SKI SHOES AND METHOD OF MAKING SAME

Filed June 13, 1966

Sheets-Sheet 1

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Jan. 9, 1968 v. drago 3,362,091

SEAMLESS SKI SHOES AND METHOD OF MAKING SAME

Filed June 13, 1966 ₄ Sheets-Sheet 2

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<img file="US3362091A_D0004.tif" />

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Jan. 9, 1968

V. DRAGO

3,362,091

SEAMLESS SKI SHOES AND METHOD OF MAKING SAME

Filed June 13, 1966

Sheets-Sheet 3

<img file="US3362091A_D0006.tif" />

Jan. 9, 1968 v. _DRAGO 3,362,091

SEAMLESS SKI SHOES AND METHOD OF MAKING SAME

Filed June 13, 1966 4 Sheets-Sheet 4

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United States Patent Office „ 3,362,091

Patented Jan. 9, 1968

3,362,091

SEAMLESS SKI SHOES AND METHOD OF MAKING SAME

Vittorio Drago, Turin, Italy, assignor to Superga Societa per Azioni, Turin, Italy

Filed June 13,1966, Ser. No. 557,013 Claims priority, application Italy, June 25,1965, 14,546/65

Claims. (Cl. 36—2.5)

The invention relates to methods of manufacturing seamless ski shoes and shoes obtained by the method.

Seamless ski shoes are known which comprise and upper formed from layers of vulcanized rubber, the said layers differing in rigidity. Such shoes are lined on the inside with a layer of expanded rubber covered by a layer of wool fabric. A rigid rubber sole and an insole, usually of the so-called orthopaedic type are secured to the said upper.

. In methods of manufacturing shoes of the above-mentioned type it is known to place various layers forming the upper, insole and sole on a last and to introduce the prepared last into an autoclave for sealing together and vulcanizing the various layers.

In ski shoes manufactured by such known methods the profile of the last is arranged to match the profile of a foot, that is to say, the last surface is formed with projections and recesses corresponding to the instep. Unfortunately, the rubber layers froming the outer wall of the upper tend to become loosened from the last surface at the said recesses during vulcanizing. This is despite thef act that they are pressed against the last during lasting and means that the outer wall of the upper of the finished shoe does not match the foot which it is intended to fit.

The upper, instead, adheres to the projecting foot parts only, and more particularly to the instep where the fastening action of the shoe clips tends to be concentrated.

In order to make the shoes more comfortable it has been proposed to provide expanded rubber pads within the upper, these pads being distributed around the instep. These are intended to fill the gaps formed between the foot and upper.

The addition of such pads, however, enlarges the shoe laterally beyond the ski width and this means that a skier wearing the shoes cannot draw his skis tightly together.

An object of the present invention is to shape the upper in accordance with the profile of the last during manufacture and to maintain the said profile after vulcanization and unlasting.

A further object of the invention is to provide a shoe having a rigid upper which uniformly compresses the

A further object is to provide a method of manufacturing seamless ski shoes, wherein an upper, an insole and a sole are placed on a last having the shape of a foot, the said upper comprising a lining, a layer of expanded rubber extending over the said lining and at least one rubber-cloth layer forming the wall of the upper, a layer of heat-setting synthetic resin is then fixed to the surface of the upper wall and a layer of rubber applied thereto, at least one portion of the upper at the instep is then compressed by means of a divided mold having its inner surface conjugated with the anatomic surface of the last, the layer of heat-setting resin heated while the upper is maintained pressed between the last and mold to cause the synthetic resin to harden, the mold removed and the lasted shoe vulcanized.

A still further object is to provide a seamless ski shoe comprising an upper, an insole and a sole interconnected by vulcanization, the upper having from the inside towards the outside a layer of lining, a layer of expanded rubber extending over the said lining, and at least one rubber-cloth layer having a Shore hardness of between 50 and 75 and forming the outer wall of the upper, a layer of heat-setting synthetic resin exceeding in hardness the rubber layer forming the outer wall of the upper hav5 ing been applied to the outer surface of the wall of the upper.

. These and other objects and advantages of the invention will be clear from the following description given with reference to the accompanying drawings which are 10 by way of example and in which:

FIGURE 1 is a perspective view of a ski shoe according to the invention;

FIGURE 2 is a sectional view taken along the line II—-II of FIGURE 1;

FIGURE 3 is a detail view of FIGURE 2 on an enlarged scale;

FIGURE 4 is a sectional view taken along the line IV—IV of FIGURE 2 and showing the shoe lasted on a last which has the profile of a foot;

FIGURES 5 and 6 are sectional views similar to FIG. 4, showing the lasted shoe and a mold in two operational positions.

Referring firstly to FIGS. 1, 2 and 3, the ski shoe will be seen to comprise an upper 1 provided with a tongue 25 2 and fastening means in the form of clips 3.

The upper is secured by vulcanization to an insole 4 and a pre-molded sole 5.

The upper 1 comprises one or two layers of rubbercloth 6 sealed together by vulcanization and having ap30 plied to their outer surface a layer 7 of a heat-setting synthetic resin mix. The layer 7 substantially covers the surface of the said layers 6.

The upper is shaped to fit a foot but is formed on both shoe sides with projections 8 in the regions above the 35 instep and with adjacent recesses 9 behind them.

The layer 7 is externally covered by a rubber layer 7α and this layer forms the outer coating of the upper 1. The rubber layers 6 are covered on their inner surface with a layer of expanded rubber 10 and a suitable lining 40 11, for instance of woolly material.

Preferably the rubber mix for the layers 6 is of a Shore hardness ranging between 50 and 75 and the heat-setting resin employed for the layer 7 is of the type marketed by Chemische Werke Huele A.G., Marl, Western Germany, 45 under the name “Duranite 3 0B,” the said synthetic resin having a butadiene base with a high styrene content and exhibiting, after heat treatment, a Shore hardness of 90-95. The layer 7 is thus stiffer then the internal layers 6. The latter, as well as the layer 7α, the expanded rubber ⁵⁰ layer 10 and the lining 11, are arranged in accordance with the foot profile and include recesses 12 and projections 13 situated respectively opposite the projections 8 and recesses 9. In this way, when the shoe is fastened by means of the clips 3, the pressure from the upper on the ^J foot is uniformly distributed, and the shoe is comfortable in use.

The main steps of manufacturing ski shoes of the type described above are shown in FIGURES 4 to 6.

„„ The first step (FIG. 4) is carried out on a suitably ^υ shaped last 14 provided at the region of the instep with projections 15 and recesses 16. The insole 4, upper 1 and sole 5 are lasted in a manner known per se.

The upper 1 comprises a plurality of layers sequentially glued to the last 14 and including an inner lining 11 ⁰ of wool, a layer of expanded rubber 10, one or two layers 6 of rubber having a Shore hardness of between 50 and 75, alternated with one or two cloth layers and a layer 7 of a mix having a base of heat-setting resin of the “Dura70 nite 30B” type. The surface of the layer 7 is covered by a layer 7α formed from a rubber having a Shore hardness of between 50 and 60. Owing to the resiliency of

3,362,091 the layers forming the upper 1, the latter does not adhere to the surface of the last 14 throughout, and tangentially engages the projections 15. As a result hollows 17 are formed adjacent the recesses 16.

At the second step (FIG. 5) the still-lasted upper is 5 laterally compressed by a heated mold made of two halves 18, 19. The said mold halves are each formed with recesses 20 and projections 21 respectively matching the projections 15 and recesses 16 in the last 14.

Compression of the mold halves on the last removes the recesses 17 and the upper 1 takes on the foot profile exhibited by the last 14, and mold halves 18, 19.

While in contact with the hot mold the layer 7 hardens and is, at the end of the treatment, of a Shore hardness of 90-95. This exceeds the hardness of the internal layers 15 of the upper.

When the mold halves 18, 19 are withdrawn from each other (FIG. 6) the layer 7 maintains the layers 6 of lower hardness, the layer of expanded rubber 10 and the lining 11 in a deformed state in accordance with the shape of 20 the last 14. In this way the upper is internally formed at the instep with recesses 12 and projections 13.

After removal of the mold-halves 18, 19 the lasted shoe is introduced into an autoclave for vulcanization.

Various modifications of the invention are of course 25 possible within the scope of the appended claims.