US3533117A - Method and apparatus for heating shoe elements for the bonding thereof - Google Patents

Description

Oct. 13, 1970 c. R. DINOLFO ETAL 3,533,117

METHOD AND APPARATUS FOR HEATING SHOE ELEMENTS FOR THE BONDING THEREOF I Filed Jan. 30, 1968 2 Sheets-Sheet 1 mvmroas.

CHARLES 2. 01/001. F0 3y 205E121 LEHR ATTORNEY Oct. 13, 1970 c. R. DINOLFO ETAL 533,117

METHOD AND APPARATUS FOR HEATING SHOE ELEMENTS FOR THE BONDING THEREOF Filed Jan. 30, 1968 2 Sheets-$heet 2 i i m- '7 l g 2 115 s Z i a; :"j Ill- I E "I i mwzmoxs.

CHARLES R. DINOLFO y ROBERT M. LEI/R ATTORNEY United States Patent Office 3,533,117 Patented Oct. 13, 1970 3 533,117 METHOD AND APPARATUS FOR HEATING SHOE ELEMENTS FOR THE BONDING THEREOF Charles R. Dinolfo, 181 Bay 28th St., Brooklyn, N.Y.

11214, and Robert M. Lehr, 11 E. 86th St., New York, N.Y. 10028 Filed Jan. 30, 1968, Ser. No. 701,606 Int. Cl. A43d 11/00 US. Cl. 12-142 7 Claims ABSTRACT OF THE DISCLOSURE A method and apparatus for selectively heating shoe uppers and soles for the bonding of the same on an assembly line basis. A plurality of matched shoe upper and sole pairs are arranged in columns on a conveyor belt which transports each column through its respective oven corridor wherein each sole and selected portions of the upper are subjected to successive stages of angle controlled infrared heat beams. The oven corridors are staggered in the direction of travel of the conveyor belt so that the heat treated shoe uppers and soles emerge from the oven in staggered locations along the conveyor belt, to thereby facilitate the unloading of each individual column of shoe upper and sole pairs by a single operator stationed alongside the conveyor belt.

The present invention relates to a method of shoe manufacture and more particularly to an assembly line method for heat treating shoe uppers and soles prior to assembly thereof, during the course of the manufacturing process, and the apparatus therefor.

High volume shoe production is recognized as an area where mass production techniques can contribute significantly to cost reduction, which is a very important factor, particularly in the highly competitive low priced shoe field.

In a typical shoe manufacturing process wherein the method of the present invention finds particular application, a shoe upper is fitted on a shoe last to maintain its proper shape, an insole is placed on the sole of the last and the lower peripheral portion of the upper is folded over the insole and secured thereto by means of suitable adhesive. The adhesive coated sole and the sole portion of the upper and insole are then heated, after which the sole is secured to the upper in a bonding operation.

In presently employed methods of shoe production each sole and shoe upper is individually handled by a series of operators during the various stages of assembly of the shoe upper with the sole. Such conventional methods suffer from the fact that excessive manual labor is required for the various shoe assembly operations, thus contributing substantially to the cost of'shoe production.

(It is therefore an object of the present invention to provide a method for automating the shoe upper and sole assembly operation by making the shoe upper and sole heat treatment process suitable for mass production and to thereby obtain the attendant cost reduction.

It is a further object of the present invention to provide a method for conveying multiple lines of shoe uppers and soles simultaneously through respective oven corridors, each providing for selectively heating the uppers and soles to the proper temperatures for bonding, the corridors being so arranged as to permit the heated uppers and soles to be unloaded and bonded in an eflicient manner by a minimum number of operators.

It is another object of the present invention to pro vide an apparatus for accomplishing the foregoing objects.

In accordance with the principles of the present invention there is provided a method for heat treating shoe uppers and soles on a mass production basis with a minimum number of operators. A plurality of shoe upper and sole pairs are arranged in rows and columns on a horizontal conveyor belt. While on the conveyor belt, adhesive is applied to the sole, and in the case of fabric uppers, to the upper as well. Each column of shoe upper and sole pairs is continuously and simultaneously conveyed through its respective parallel oven corridor Wherein each sole and selected portions of the upper are subjected to successive stages of angle controlled infrared heat beams. The oven corridors are parallelly arranged and are staggered in the direction of travel of the conveyor belt so that the heat treated shoe uppers and soles emerge from the oven in staggered locations along the conveyor belt, to thereby facilitate the unloading of each column of shoe upper and sole pairs by a single operator stationed alongside the conveyor belt. Upon removal from the conveyor belt each heat treated sole is secured to its corresponding heat treated upper by means of a press, in a bonding operation.

The features of the invention which are believed to be novel are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and method of operation, together with further objects and features thereof may best be understood by reference to the following description taken in conjunction with the accompanying drawings wherein:

FIG. 1 is a perspective View of a shoe upper and a fragmentary view of a sole to be heat treated and secured thereto in accordance with the principles of the present invention;

FIG. 2 is a perspective view of a portion of the apparatus for carrying out the method of the present invention, with a part of the apparatus broken away and shown in section;

FIG. 3 is a top plan view of the apparatus shown in FIG. 2; and

FIG. 4 is an enlarged sectional view of the apparatus taken along line 44 of FIG. 3.

Referring to FIG. 1, in preparation for heat treatment as hereinafter described, a shoe upper 10 is fitted on a shoe last 12, and its lower peripheral edge 14- is folded over the peripheral portion of an insole 16 and secured thereto by means of suitable adhesive to form a shoe upper assembly 18. An outer sole 20 is provided, to be secured to peripheral edge 14 of upper 10 and insole 16, after having been heat treated in accordance with the principles of the present invention as hereinafter described. In the case of shoes having vinyl uppers, only sole 20 is coated with adhesive, whereas in the case of fabric uppers, both sole 20 and the fabric upper portion 14 are cemented.

The general objective of the present invention is to provide a method of heat treating shoe upper assembly 18 and sole 20 for assembly on a mass production basis. For this purpose, referring to FIGS. 2 and 3, there is provided an oven 22 divided into parallel elongated oven corridors A, B, C and D, with each oven corridor being further divided into four sections, e.g. A-l, A-2, A-3, and A-4, each containing a heating element for successively subjecting each shoe pair, consisting of an upper assembly 18 and sole 20, to four successive heating stages as hereinafter described. In order to feed the shoe upper and soles through the various successive heating stages, there is provided a horizontal conveyor belt 24, mounted on a supporting work table (not shown). Conveyor belt 24 may be regarded as divided into four parallel tracks A, B, C', and D aligned with the respective oven corridors, A, B, C, and D. The upper assembly 18 and sole 20 pairs are arranged in columns on con-veyor belt 24 with each column on its corresponding track, so that one column of upper assembly 18 and sole 20 pairs is transported through its respective oven corridor, wherein they are subjected to the above mentioned successive heating stages. The successive heating stages selectively heat the adhesive coated sole 20 and the folded portion 14 of the upper causing the adhesive to set, so that upon emergence from oven 22, each heat treated upper assembly 18 and sole 20 may be pressed together in a bonding operation.

As shown in FIGS. 2 and 3, the pair of inner oven corridors B and C which are in lateral alignment, are longitudinally offset from outer oven corridors A and D, the latter corridors also being in lateral alignment with each other. This staggered configuration of the oven corridors realizes an important feature of the present invention, whereby the upper assembly and sole pairs emerge from their respective oven corridors in staggered positions on conveyor belt 24. This arrangement permits the unloading of an outer column of shoe uppers and soles, e.g. on track A, by one operator, and the unloading of the other inner column, e.g. track B, by a second operator stationed further along conveyor belt 24. This arrangement eliminates any possible interference between operators, who Would otherwise have to be stationed at the same location to unload the two columns of shoe uppers and soles 'which would be emerging from oven 22 at the same time.

The loading and heat treatment process will now be described in detail. Referring to FIG. 2, the matched pairs of lasted upper assemblies 18 and soles 20 are loaded on conveyor belt 24 at loading station 26, comprising a frame 28 supporting vertical partitions 30, 32, and 34. These partitions form loading stalls for ensuring that the matched pairs are loaded on conveyor belt tracks A, B, C, and D in alignment with the respective oven corridors A, B, C, D. Operators stationed at the end of the table, for example at stations 38 and 40 shown in FIG. 3, load the matched shoe pairs in rapid succession within the various loading stalls defined within frame 28.

In loading the shoe pairs, each lasted upper assembly 18 is seated on the conveyor belt 24 with the side of the shoe upper 10 resting on the top surface of belt 24 in such a manner that the insole 16 is positioned at a slight angle to the vertical and is facing the adjacent edge of the conveyor belt 24. Thus, in FIG. 4 it will be observed that the two shoe uppers 18 on conveyor belt tracks A and B are so inclined that their insoles face the right hand side of the conveyor belt, while the insoles of the shoe uppers on conveyor belt tracks C and D face the left hand side of the conveyor belt. Further, in each matched pair, the corresponding outer sole 20 is placed flat on conveyor belt 24, alongside and slightly spaced from the lasted upper assembly 18. In each instance, the outer sole 20 is placed on the side of the corresponding upper assembly 18 in the direction of the adjacent edge of the conveyor belt 24, as shown in FIGS. 1 and 4.

After loading, the columns of upper assembly and sole pairs are transported by conveyor belt 24 in the direction of arrow 42 (FIGS. 2 and 3) toward the respective oven corridors A, B, C, D to be subjected to the successive heating stages. During such travel, operators stationed at the sides of the conveyor belt between the loading station 26 and the oven entrances, apply coatings of adhesive or cement to the lasted upper assembly 18 as well as the outer sole 20 of each matched shoe pair.

Each of the oven corridors A, B, C, and D comprises four successive heater stages, e.g. in corridor A, stages Al, A2, A3, and A4, for sequentially heating each upper assembly 18 and/or sole 20 as hereinafter described.

As best shown in FIG. 4, each heating stage comprises a horizontally disposed linear type infrared heat lamp 44 partially surrounded by a parabolic reflector 46 for controllably projecting an angle controlled heat beam 48 to 4 preselected portions of the upper assembly 18 and/or sole 20.

As shown in FIG. 4, each of the linear infrared heat sources 44 is offset sideways from its corresponding conveyor belt track so that the heat beam 48 emanating therefrom is oriented angularly toward said corresponding track. Thus, each heat beam is adapted to impinge on the folded-over portion 14 of the upper 10 which is positioned at a slight angle to the vertical, as well as upon the horizontally-disposed sole 20, as required in the particular heating stage. The housing for oven 22 comprises rectangular section enclosures 50, 52, 54, and 56 forming oven corridors A, B, C, and D respectively, and a pair of inwardly- inclined side walls 58 and 60 extending from outer walls 62 and 64 of outer compartments 50 and 56 to adjacent the side edges of conveyor belt 24.

A central partition 66 is provided between tracks B and C, as shown in FIG. 4, to prevent overlapping of the heat beams emanating from the inner corridors B and C. In addition, suitable exhausts (not shown) may be provided for removal of hot air that is generated during the heating process.

The successive heating steps will be described for oven corridor A, it being understood that the heating process is identical in the other oven corridors, B, C, and D.

In the first heating stage, e.g. stage Al, reflector 46 is so shaped and oriented as to provide an infrared heat beam 48 directed to avoid upper assembly 18 and to impinge only on sole 20. In this stage heat beam 48 is at a temperature of 110 F. Thus, as assembly 18 and sole 20 are transported through first heating stage Al, only sole 20 is heated. This first stage is indicated in FIG. 4 with relation to the stage C-l which is identical to stage Al.

Conveyor belt 24 continues to transport the upper assembly 1-8 and sole 20 pair through the second heating stage, i.e. stage A2, where an infrared heat beam at approximately 110 F. is directed at both sole 20 and folded-over portion 14 of upper 10, as well as the exposed portion of insole 16. This is illustrated for stage B-2 in FIG. 4. It will be noted that the heat beam does not impinge upon the side and top portion of the upper assembly. In this way, the adhesive which had previously been applied to folded-over portion 14 of upper 10 and to sole 20 sets, i.e., dries.

The upper assembly 18 and sole 20 are then further transported through a third heating stage, i.e., stage A3, where only the folded-over portion 14 of upper 10 as well as the insole 16 are flash heated at a high temperature, i.e., approximately 200 F. This stage is exemplified by by stage D-3 shown in FIG. 4, wherein it will be noted that the heat beam avoids the outer sole 20. In this Way, folded-over portion 14 of the upper becomes hot, but not so hot as to cause it to separate from the insole 16- i.e., to cause popping. During this heating stage the infrared heat beam is again focussed and directed to impinge only on insole 1 6 and folded-over portion 14, while avoiding the remaining portions of upper 10.

Conveyor belt 24 continues to transport upper assembly 1 8 and sole 20 through a fourth heating stage A4, illustrated in FIG. 4, which is similar to stage A3, and wherein the heating process of stage A3 is repeated, that is to say, the lower surface of upper assembly 18 is subjected to flash heat at relatively high temperature.

It is to be understood that the apparatus of the present invention is not limited to the specific dimension of the conveyor belt 24 or oven 22. However, by Way of example, in one suitable arrangement, conveyor belt 24 has an overall length of approximately feet and a width of about 40 inches. In this arrangement, the oven 22 has an overall length of 22 feet, with each oven corridor being 14 /3 feet long, and each heating stage is about 3% feet in length. Each oven corridor is approximately one foot wide. Conveyor belt 24 may have a selectively variable speed of five to fifteen feet per minute with a typical average speed of 10 feet per minute, in which case the time cycle, i.e. the total heat treatment period for each shoe upper and sole, is approximately one minute twenty seconds.

Control of the infrared heat beam angular orientation and beam width in the various heating stages A-l A-4, may be accomplished by means of additional reflectors (not shown) which may be located below linear infrared heat lamp 44 and which serve to selectively direct the respective heat beams 48 solely onto folded upper portion 14, or solely upon sole 20, as the case may be.

Since the beam width and angular orientation of heat beam 48 are preset, it is important that upper assembly 18 and sole 20 of each matched pair be accurately positioned in their proper track when being loaded at station 26, so that they will receive the proper degree of heat from the various beams 48 as they are transported through the oven 22 by means of conveyor belt 24.

It will now be approciated that as each matched pair is transported through the oven 22, it is subjected to a continuous heating operation in which relatively low heat is applied to the outer sole 20 over a relatively long period (i.e., two stages) for drying the cement thereon. Thereafter, the upper assembly, which has been preheated, is subjected to a short period of relatively intense heat so that the cement dries and sets, and the upper becomes sufiiciently hot to permit the subsequent bonding operation. As soon as the upper assembly and matched outer sole emerge together from the oven, an operator applies the outer sole to the heated upper assembly under pressure in a power press. The hot upper assembly heats and plasticizes the adhesive coating on the outer sole, resulting in firm bonding of the completed shoe parts.

In practice, at one side of conveyor belt 24, a first operator is located at unloading station 66, adjacent the area in which the heated shoe pairs emerge from oven corridor A. This operator removes the shoe pairs as fast as they emerge from corridor A and is provided with a power press for bonding the outer sole 20 to the upper assembly 1 8 while the latter is still hot. A second operator is located on the same side of the conveyor belt at unloading station 70 adjacent the area in which heated shoe pairs emerge from the oven corridor B, the station 70 being further along the conveyor belt. This second operator is also provided with a power press which he uses to bond the shoe pairs removed from the conveyor belt as fast as they emerge from oven corridor B. The bonding operation is duplicated on the opposite side of the conveyor belt 22 by another pair of operators located at unloading stations 68 and 72 for bonding the shoe pairs emerging from the respective oven corridors D and C.

Thus, the staggered or oflFset relationship of the oven corridors A, B, C, D in conjunction with the single conveyor belt realizes an important feature of the invent1 on whereby the bonding operators may each service an individual oven corridor Without interfering with each other. In this manner a smooth rapid, and highly eflicient unloading and bonding operation is efiected.

A heel- (not shown) may be suitably secured to the heel portion of sole 20, in any well known manner, prior to the loading of sole 20 on conveyor belt 24. In this way the bonding operation described above will complete the shoe assembly operation.

A preferred embodiment of the invention has been shown and described herein. It will be obvious that numerous omissions, changes and additions may be made in such embodiment without departing from the spirit and scope of the invention.

What we claim is:

1. A method of shoe manufacture comprising loading a plurality of lasted shoe uppers and matched soles on transport means with each shoe upper being paired with a corresponding sole for assembly therewith, applying adhesive to each of said soles, transporting said sole and said shoe upper pairs in unison through an oven, projecting angle controlled heat beams onto each of said soles and a pre-selected portion of each of said shoe uppers while said soles and shoe uppers pass through said oven, to thereby condition said soles and shoe uppers for securing each of said soles to its said paired shoe upper after emergence of each of said upper and said sole pairs from said oven, said shoe upper and sole pairs being disposed on said transport means in a plurality of columns for simultaneous transport of said columns through said oven, with the upper and sole pairs of each of said columns being successively subjected to a series of heat beams spaced apart in said oven, while travelling through said oven, each of said soles being positioned proximate to and in transverse alignment with its paired shoe upper on said transport means, and the first heat beam of said series being projected upon the upper surface of said sole and being of sufficient temperature to dry and set the adhesive on said sole.

2. A method as defined in claim 1 wherein the second heat beam of said series is at approximately the same temperature as said first beam and is projected onto the lower surface of said lasted upper and onto said upper surface of said sole.

3. A method as defined in claim 2 wherein the third and fourth heat beams of said series are at a relatively high temperature and are projected solely upon the lower surface of said lasted upper.

4. A method as defined in claim 3 wherein an individual heat beam series is provided for each of said columns of shoe pairs, the beams of at least some of said series being in longitudinally offset and staggered relationship to the beams of other series, whereby the shoes of the corresponding columns emerge at different locations from their respective heat beam series.

5. Apparatus for shoe manufacture comprising conveyor belt means for transporting matched pairs of shoe uppers and soles placed thereon along selected longitudinal tracks, an enclosed oven overlying said conveyor' belt means and comprising a series of elongated oven corridors extending longitudinally of said conveyor belt means, each of said oven corridors being disposed above and in substantial longitudinal alignment with a corresponding one of said conveyor belt tracks, each oven corridor containing a plurality of heating elements arranged in a longitudinal series to provide selectively variable heat beams directed at the aligned conveyor belt track, whereby when said matched pairs of shoe uppers and soles are disposed on said conveyor belt means to form pair columns transported along respective belt tracks, said heating elements of the series contained in the aligned oven corridor are operative to apply heat to each of said soles and preselected portions of each of said shoe uppers in success1ve stages as said columns are transported past the correponding longitudinal series of heating elements, each of said oven corridors comprising a plurality of successive longitudinally arranged heating stages, each of said heating stages containing one of the heating elements of a longitudinal series, each heating element being operative to produce a heat beam of a pre-selected temperature and being adjustable for selective variation of the angular orientation and width of said heat beam, whereby said shoe upper and sole pairs are successively subjected to variously adjusted heat beams as each of said columns is transported through its respective oven corridor.

6. Apparatus as defined in claim 5 wherein each of said heating elements comprises a longitudinal heat source and reflector means operative to form the heat rays emanating from said source into a heat beam whose angular orientation and beam width is selectively variable.

7. Apparatus as defined in claim 5 wherein said oven is formed of a first pair of centrally located corridors and a second pair of oven corridors bracketing said first pair and located outwardly thereof, the corridors of said first pair being in lateral alignment with each other and the corridors of said second pair being in lateral alignment with 7 each other, the first of corridors being laterally offset and staggered with respect to said second pair.

References Cited UNITED STATES PATENTS 8 3,220,033 11/1965 Bromfield et a1 121 3,256,420 6/1966 Werman 121 X FOREIGN PATENTS 842,170 7/1949 Germany.

PATRICK D. LAWSON, Primary Examiner US. Cl. X.R. 121

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