US3220036A - Process for mulling shoe uppers - Google Patents

Description

Nov- 30, 1955 M. s. BROMFIELD r-:TAL 3,220,035

PROCESS FOR MULLING SHOE UPPERS 8 Sheets-Sheet 1 Original Filed March 6, 1962 S S M w T. N m W H w m E w 1 M A 5 E J m 0. .mmm m m m m mvrm R um Gv M G Q las@ WMU T Q inw $.23 m Y Sm Hmm Q l N B m QU @YN/1U@ s mm@ mmmmllmwd W1 mw Q 4| @.mnhwnmmwn www SQSNM 595mm mgm,

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NOV. 30, 1965 M. s. BROMFIELD ETAL 3,220036 PROCESS FOR MULLING SHOE UPPERS 8 Sheets-Sheet 2 Original Filed March 6, 1962 INVENTORS MORTO/V SROMF/ELD JACK 7. FERNER ATTORNEYS NOV. 30, 1955 M. s. BRoMFH-:LD ETAL 3,220,036

PROCESS FOR MULLING SHOE UPPERS Original Filed March 6, 1962 8 Sheets-Sheet 5 INVENTORS` M05 7'0/V 5. BRMF/[LD JACK D. FER/VER ATTORNEYS N0 30, 1965 M. s. BRoMFll-:LD ETAL 3,220,035

PROCESS FOR MULLING SHOE UPPERS Original Filed March 6, 1962 8 Sheets-Sheet 4 d 64 62 97 I 3 ,6/ 66 99/0 7, 65 69 g 79 59 ,a 55 60 g.4 74 760 6 74 6/ 8 78 56 IN VENTOR 5 MOR TON Sy BHOMF/E'LD JACK D. FER/VER www @www ATTORNEYS Nov. 30, 1965 M. s. BROMFIELD ETAL 3,220,036

PROCESS FOR MULLING SHOE UPPERS 8 Sheets-Sheet 5 Original Filed March 6, 1962 INVENTORS MORTO/V S BRO/WF/ELD JACK D. FER/VER ATTORNEYS NOV 30, 1955 M. s. BROMFIELD ETAL 3,220,036

PROCESS FOR MULLING SHOE UPPERS Original Filed March 6, 1962 8 Sheets-Sheet '7 INVENTOR5 MOR/V 5.13R0MF/ELD JACK D. FER/VER ATTORNEYS United States Patent O 3,220,036 PRUCESS FR MULLING SHE UPPERS Morton S. Bromfield, 8 Hubbard St., Canton, Mass., and Jack D. Ferner, Lowell St., Carlisle, Mass.

Original application Mar. 6, 1962, Ser. No. 177,785, now

Patent No. 3,161,898, dated Dec. 22, 1964. Divided and this application Apr. 23, 1963, Ser. No. 285,540

1 Claim. (Cl. 12-142) Our invention relates to shoemaking, and particularly to improved methods for lasting and soling shoes. This application is a division of our copending application Ser. No. 177,785, filed March 6, 1962, now U.S. Patent No. 3,161,898, entitled Shoemaking In the manufacture of shoes, it is extremely important to limit the number of operators required, the time that the operators spend in performing operations other than those for which they are specially trained, and the number of operations which they must perform. In addition, the overall time required to manufacture a shoe should be kept as small as possible. Numerous improvements have been made in the past which expedite some of the operations required in shoemaking. For example, in United States Patent No. 2,973,531, tiled September 3, 1959, by Morton S. Bromfield for Method for Mulling Shoe Uppers, and issued March 7, 1961, an improved method of mulling uppers is disclosed which greatly reduces the time required for this operation.

In United States Patent No. 2,973,530, filed May 4, 1959, by Morton S. Bromfield for Method of Manufacturing Shoes, and issued March 7, 1961, an improvement in shoemaking is disclosed which consists essentially of introducing into the outer surface of a shoe upper just enough water to increase the exibility of the surface zone, lasting the upper before the water can pervade the central zone of the upper, and then heating the shoe to remove the water before it can penetrate the upper.

Our present invention provides an improved mulling process for shoe uppers, in which the uppers are sequentially conveyed through a water-saturated atmosphere at elevated temperatures. The water-saturated atmosphere is best provided in a tunnel, and as the uppers are passed through the tunnel, the moisture condensing on its walls is collected so that it cannot drip on the uppers; a fine mist of water, at the temperature of the atmosphere of the tunnel, is periodically sprayed upwards so that it rises and then falls on the uppers; the spraying operation is periodically abruptly and positively shut off. By controlling the duration of the spraying periods, it is easily possible to maintain the exactly desired water mist atmosphere in the tunnel, without overmoistening the uppers. The provision for sudden shut-off prevents after flow from the spray nozzles, which would render precise control impossible.

Our invention will best be understood by reference to the accompanying drawings, together with the following detailed description of a preferred embodiment thereof.

In the drawings:

FIGURE 1 is a schematic plan view of shoemaking apparatus embodying our invention, and illustrating the novel process of shoemaking of our invention;

FIGURE 2 is a diagrammatic illustration of a portion of the shoemaking apparatus of FIG. 1, showing details of the conveyor and drier system, and including a crosssectional elevation of the muller of our invention;

FIGURE 3 is a perspective view, with parts shown in cross-section and parts broken away, of the novel last and sole conveyor employed in the apparatus of FIG- URES 1 and 2;

FIGURE 4 is a cross-sectional end view through the novel toe steamer of my invention, also showing a cross- 3,220,936 Patented Nov. 30, 1965 "ice sectional end view at a typical section of the novel last and sole conveyor of FIG. 3;

FIGURE 5 is a typical section through the muller of FIG. 2, taken essentially along lines 5-5 of FIG. 2;

FIGURE 6 is a schematic wiring and piping diagram showing the control apparatus for the muller of FIG. 2;

FIGURE 7 is a typical section through the novel drier employed in the apparatus of FIG. l; and

FIGURE 8 is a typical section through the novel activator unit employed in the system of FIG. l.

Referring rst to FIG. l, we have shown a typical shoemaking operation, namely, the manufacture of womens high heeled shoes. As will be apparent from the following description, by simple substitution of the appropriate manual operations, this process can readily be applied to the manufacture of mens or childrens shoes. The invention is applicable to shoes of leather or of plastic material. The term shoes used herein is intended to cover all kinds of footwear, e.g. boots, shoes, slipper or sandals.

In FIG. l, the stations of manual operators are indicated schematically by circles with appropriate labels, and it will be understood by those skilled in the art that these operators will be provided with the necessary benches, machinery and tools to perform their respective functions.

The central element in the shoemaking process of our invention is the conveyor, here schematically shown as a line 1 which is assumed to run in the direction of the arrows around drive sprocket 2, and idler sprockets 3, 4, 5, 6, 7 and 8. Before describing this conveyor in detail the overall lasting and soling process will be briefly described.

The rst step in the portion of the shoemaking process here illustrated is the placement of lasts with insoles attached and cemented out-soles on the conveyor 1, and the placement of associated stitched uppers on a conveyor belt at the entrance end of a muller 9. These operations are performed by a put-on operator whose station is schematically indicated by the circle 10. Depending on the material from which the uppers are made, these are taken either from a rack 11 of leather uppers which have been stitched at the heel, or from a vinyl preheater 12 for uppers of polyvinylchloride or other plastic material.

At the exit end of the muller 9, one or more assemblers whose stations are schematically indicated by the circles 13 and 14 removed the mulled uppers emerging from the muller 9, removed the associated lasts from the conveyor 1, and assemble each upper on the associated last with tacks. As the next operation, the pullover operator, whose station is schematically indicated by the circle 15, performs the function of pulling the uppers over the lasts, in a conventional manner which is facilitated by the manner of mulling, as will appear. These operations are followed by the lasting operations performed by side lasters and a forepart laster, whose stations are schematically indicated by the circles 16, 17 and 18, respectively. The forepart laster, having completed his operation, places the partially lasted uppers on the conveyor 1 for travel through a toe steamer schematically indicated at 19.

As will appear, the toe steamer 19 is so controlled and arranged that in a first portion, that their toes and their thermoplastic stitfeners are conditioned with heat and moisture sufficiently for bed lasting, and this condition is maintained without a substantial increase in moisture during the latter portion of the travel through the toe steamer 19. Thus, a rst bed laster, whose station is schematically indicated by the circle 20, may take, say, the rights, and a second bed laster, whose station is schematically indicated by the circle 20', can take the lefts, both rights and lefts being similarly and optimally conditioned for the lasting of the toe.

Following the bed lasting operation, a heel-seat laster whose station is schematically indicated by the circle 21 may tack in the heel `seat in a conventional manner, and then place the lasted uppers on the conveyor 1 for travel through an upper dryer schematically indicated at 22 which is divided into a plurality of sections, here shown as three sections 23, 24 and 25 for progressive controlled removal of the moisture in the uppers. As will appear, the speed of the conveyor and the controls for the muller 9 and the dryer 22 may be so adjusted that the shoemaking process disclosed in the above-mentioned Patent No. 2,973,530 may be carried out with great eciency and uniformity of results.

After the shoes have left the upper dryer 22, the excess portion of the overlasted uppers is removed by a trimmer and insole tack remover whose station is schematically indicated by the circle 26, and the lasts then pass to an inspector and crowner, whose station is schematically indicated by the circle 27, who notes any defects, makes minor corrections, and puts aside shoes requiring major correction for further Work. The shoes are then processed in the normal manner by a pounder located as schematically indicated by the circle 28, a rougher located as schematically indicated by the circle 29, and a shanker, Whose station is schematically indicated by the circle 30.

Having performed his operation of inserting the shank, and where necessary or desirable, filling with cork composition or the like, the crevices which would otherwise interfere with the proper laying of the sole, the shanker places the lasted upper on the conveyor 1 in association with its outsole `for travel through an oven generally designated at 31. The oven is provided with one or more preheating units such as 32` and 33, which may be elongated heaters of conventional types, and which preferably do not provide heating throughout the entire run through the oven 31, as less heating time is generally required in the pre-heating stage than in the subsequent drying stage. The function of these preheaters is to provide a reservoir of heat in the upper and sole which will serve to condition the inner portion of cement which is applied by a cementer stationed as schematically indicated by the circle 34. The cementer applies cement to the overlasted margin of the shoe bottom, the outsole having previously been `coated with cement as described above, and then places these parts on the conveyor 1 for a second passage through the oven 31, past a plurality of cement driers schematically indicated at 35, 36 and 37, which extend substantially over the entire length of the oven. Since this oven performs a conventional function, and need consist of only an open housing over the conventional mounting means for the conventional heating elements, it will not be described in further detail. It is sufficient to note at this point that the overlasted margins and outsoles emerging from the oven are coated with cement from which the solvent has been evaporated. `These cemented parts will then be passed to the heel attacher, whose station is schematically indicated by the circle 38, and who, in the case of a womans shoe, attaches a heel to the heel seat with a temporary screw in a conventional manner. If mens or -childrens shoes, or Hat-heeled Womens shoes are to be manufactured, this operator may be dispensed with.

The heel attacher places the lasts carrying the 4cemented uppers and the outsoles on the conveyor 1 for passage through an activator generally designated at 39 which comprises a sole activator 40 and a shoe bottom activator 41. Arrangement of the Various heating units within this activator 39 will be described below.

Following the activator 39, a sole layer, located as schematically indicated by the circle 46, removes the components from the conveyor 1 and lays the cemented outsole on the cemented shoe bottom, and, in the case of the sole employed in womens shoes, over the breast of the heel. The nished shoes are then placed in a suitable rack 47 for last pulling and any other operations which may be necesary or desirable.

Referring now to FIG. 2, the conveyor 1 of FIG. l comprises a longitudinal guide member 48 which is supported at suitable intervals by pipe stands indicated at 49 and 50 which are provided with floor caps such as 51 and 52 and channel engagement members such as 53 and 54, respectively, of which the latter will be described in more detail below. Mounted for movement with respect to the guide channel 48 are a plurality of last and sole conveyors 55 for conveying lasts such as 75 and soles such as 90 throughout the system.

Referring now to FIGS. 3 and 4, the construction of the guide channel 48 and the last and sole conveyor 55 are shown in more detail. As shown, the guide channel 48 is in the form of a generally Ueshaped, elongated channel provided with horizontal support and bearing lugs 58 on either side of the inner portion thereof to support a block 59, which is preferably of nylon or the like, but may be of any suitable low friction material, and which forms a support for the last and sole conveyor 55. Upper lugs 60 are provided on the guide channel, as shown, to prevent the accidental removal of the block 59.

Sets of opposed lips 61, 62 and 63 are provided on the sides and bottom of the guide channel 48, respectively, for use in attaching the guide channel to various other elements. For example, the lower lips 63 may be employed to engage the rim of a fitting 64 which is threaded into a pipe coupling 65, the latter being in threaded engagement with a pipe such as 66 to form a pipe stand such as 49 and 50 in FIG. 2. Suitable washers of resilient material, as schematically indicated at 67, may be employed to permit a firm engagement of the lips 63 with the upper flange of the fitting 64 without scoring of the bottom of the channel 48 by the coupling 65. It will be apparent that similar use of the lips 61 and 62 may be made to attach various accessories to the conveyor channel 48.

The last and sole conveyor support block 59 is attached by suitable means such as screws 68 to a bracket 69 welded on or otherwise attached to a link of a conveyor chain generally designated at 70. As best shown in FIG. 3, the conveyor chain 70 generally is of a conventional construction which will be readily understood without fur` ther description.

The various lasting operators may drop tacks around and about the conveyor, and unless removed, these may accumulate to an extent that damage to the conveyor may result. In order to remove these and other foreign objects, one or more paddles 71, of rubber or the like, as shown in FIG. 4, may be attached to a suitable bracket 72, which in turn is screwed to a lower link of the chain 70 in a suitable conventional manner. As will be apparent from the drawings, the paddle 71 will be swept along the base of the channel formed in guide member 48 to contact any foreign articles such as tacks 73 and convey them to a suitable disposal point, which may be lon cated at any desired place along the conveyor by providing an aperture along the base of the channel 48 through which they will fall.

As shown in FIGS. 3 and 4, the support block 59 of conveyor 55 is provided with side lugs 74 which engage the support lugs 58 of the guide channel 48 for longitudinal sliding support. As best shown in FIG. 4, a last 75 may be supported on the support blocks 59 by means of a post 76 which is threaded at one end and has its threaded end extending through a hole in the block 59, where it is secured by means of nuts 77 and 78. A spring 79 surrounds the post 76 and extends between a washer 80 on nut 77 and a shoulder formed on a collar 81. Collar 81 is provided with a last support shelf 82 having upstanding portions 83 at the corners thereof for engaging the sides of the last 75 in either of four positions 90 apart.

The collar -81 is retained on the .post 76 against hichmax, i

be of a conventional split construction engaging a groove on the post 76, not shown. By this construction, it will be apparent that the last will be held in either of the two orthogonal positions normally required, but may be turned from one to the other of these positions by grasping the last 75 and turning it with a force sufficient to overcome the friction between the collar and the spring 79 at one end and between the shelf 82 and the retaining ring 84 at the other end.

Associated with the last supporting post 76, and mounted on the support block 59, is a sole conveyor member generally designated at 85 which is bent over in the manner shown in FIGS. 3 and 4, being provided with a lug 86 for attachment to the block 59 by means of the post 76 and the nuts 77 and 78, as shown. An aperture 87 is provided at the upper part of sole carrier 85 to permit free passage of the collar 81.

A sloping shelf portion 88 is formed on the other side of the sole conveyor 85, and a serrated base portion 89 extends along the bottom edge of the sloping shelf 88 as shown. Retaining clips for the sole, the latter being indicated by dotted lines 90 in FIG. 4, are provided by a wire 91 which is bent as indicated in FIG. 3 to form a rst upstanding portion 92 which extends through a hole in the base portion 89 of the sole conveyor 85, being retained by a clip 93, and is bent backwards and then bent again along the axis of the conveyor to form a portion 94 indicated by the dotted lines which engages a suitable groove 95 in the support block 59, past which it is bent again to form another upstanding portion 96 which is retained by a clip 97 in the same manner as clip 93 retains the upstanding portion 92.

The portion 94 of the wire 91 is retained, as shown in FIGS. 3 and 4, by the lug 86 formed on the back portion of the sole conveyor 8S. Preferably, the wire 91 is made of a thin material which will retain the sole and yet not interfere with the activation of cement thereon, such as 1A; in. dia. stainless steel wire.

It will be apparent that by the above described construction, both the lasts and soles of a shoe may be progressed through the various shoemaking operations together, and yet be readily available to the operator, or accessible to the automatic equipment for processing.

Referring again to FIG. 2, the conveyor chain 70 is driven lby a drive sprocket 2, which in turn is driven through a suitable gear box 98 by a motor 99. Generally speaking, box 98 will be selected to provide a speed reduction such that the chain 70 will travel at approximately 6 feet per minute; of course, this Speed may be varied widely for special operation, and is given merely as an indication of a typical speed suitable for the usual Shoemaking operation.

As Ishown in FIG. 2, the idler 3 has attached thereto an auxiliary drive shaft 100, which, through suitable bevelled gears and an over-riding clutch, not shown, drives the drive roll 101 of the conveyor belt 102 for the muller generally designated at 9. In some instances, it will be -desirable to run the muller conveyor for a time independently of the conveyor chain 70, as Ito remove uppers from the muller when the rest of the apparatus is shut down. For this purpose, as indicated, an auxiliary drive motor 103 may be provided to drive the motor 101 through the overriding clutch mentioned above. It is believed that this arrangement is sufficiently conventional and obvious that it does not require detailed description.

The drive assembly, together with a pump 104 for the muller sprays, to be described, which is driven by motor 99, is mounted in a suit-able housing 105, and conventional means schematically indicated as an opstanding bracket 106, or other support means, are provided to support the muller above the conveyor 1. If desired, a separate drive motor can be provided for the pump 104.

The muller will be described by reference to FIGS. 2 and 5. However, before describing the muller in detail, its function Will be briefly considered. As is known, in

order to expedite the mulling process, it is desirable to mull the shoe uppers in a saturated atmosphere at a temperature between 140 and 180 F., while applying a very tine spray to the uppers. One of the more important requirements in ca-rrying out this process is the prevention of water droplets of appreciable size from falling on the upper, since such a droplet will cause staining which it is not practical to remove, and which ruins the appearance of the shoe. Thus, it is highly essential to prevent any dripping in the muller, as well as to avoid splashing from the conveyor or from the water tank, Iand to maintain the sprays in uniform operation during mulling so that they provide only a very ine mist of water droplets.

Again, it is very desirable that the time required lby the muller to complete its operation be redu-ced to a minimum. In addition, lit has been found quite difficult to maintain ra suitable mulling mist in the muller by the continuous operation of Spray nozzles. In part, this is because the use of sufficient spray to cre-ate a uniform mist will overmoisten the uppers if run continuously, whereas a smaller number of nozzles would not crea-te the desired uniform atmosphere. Of course, the nozzles co-uld be made smaller, but this would not be an effective expedient, both because the range of each nozzle would be decreased, and because a smaller nozzle is much more likely to fail through clogging, and to :spray unevenly. We have attempted to overcome this diiculty by intermittent operation of the sprays, which desirably controls the amount of mist introduced, but raises a serious problem caused by afterflow of the nozzles as the pressure in the expande-d lines feed-ing the nozzles is gradually relieved. As will appear, we have found an eicient means for elimina-ting this fault, so that the nozzles will shut off abruptly. By this means, we are able to 4control the amount of sprayed moisture over wide limits.

It has been found lthat if the number and dimensions of the nozzles were selected for optimum continuous use for one particular type of upper leather stock, the operations on other types of upper stock would not be satisfactory. It would of course be impractical to attempt to replace the nozzles every time a different type of upper `stock was to be processed. However, by providing for pulsed or intermittent operation, the desired adjustments can easily be made merely by varying the frequency and duration of the spray periods.

The control over the sprayed moisture makes possible a further improvement in the operation of the muller. We have found that the rat-io between the surface moisture absorbed in the grain side of the upper and the moisture absorbed on the flesh, or corium, side, can be controlled by controlling the relationship between the amount of moisture introduced by steam from a Water tank in the base of the muller and the amount of moisture introduced by the spray nozzles. Specifically, we have found that by increasing the relative amount of sprayed moisture, the grain side of the upper will be moistened proportionately more than the flesh side, whereas by increasing the relative amount of water Vapor applied from the steam pipe, the reverse effect may be achieved. As `will appear, the novel muller Iof our invention is operable to select any desired balance between the moisture applied to the surface of the grain side and the moisture applied to the esh side ot the upper.

In the `earlier patents previously referred to we speak of providing a substantially relative humidity in the muller. This is achieved primarily by an elevated mulling temperature, which according to the psychosometric charts, shows a disproportionate increased ability :of heated air to hold moisture. `Sec-ondarily, warm moisture is me. chanically sprayed on to the upward facing surface of the leather uppers. In the horticultural iield it has been found that leaf structures are aided in growth by super-saturated atmospheres; whereas such atmospheres have been created by elevating temperatures it had been thought that heat was essential to the accelerated growth. However, su-

per-saturation has proved to 'be the key element Iand it is this super-saturation which has been found to be an important fa-ctor to accelerated moisture `absorption by leather from a super-saturated atmosphere. This supersaturation is best achieved by using a high pressure, for example in excess of 150 lb./sq. in., absolute in combination with spray nozzles capable of producing a finely atomized spray or mist.

Whereas leather has generally some thermo-plastic properties advantage can best be taken of these characteristics to obtain optimum workability by introducing as hot a sprayed mist as can be mechanically introduced without the danger of creating ilashes of steam. To this end, in accordance with the invention relatively cold pressurized water is heated at the closest point to the spray yformation so as to eliminate the difficulties of creating steam under high pumping pressures as well as to minimize the temperature drop beyond the point of heating. Therefore, there is provided a means of heating pressurized water at or near the point of atomization with a minimal line volume of pressurized heated water.

Referring next to FIGS. 2 and 5, the muller 9 comprises an outer cylindrical shell 107, which may be made of any suitable material, but which, in accordance with a preferred embodiment of our invention, is made of a ber glass filled resin. An inner shell 108, which may be made from the same material as the outer shell, and has a cross-section of the type shown in FIG. 5 for reasons which will appear, is disposed within the outer shell. The space between shells 107 and 108 is filled with `an insulating and structural support composition 109, which may be selected from a wide range of material, but which is preferably of polyurethane foam.

In order to maintain a uniform atmosphere in the muller, and to conserve heat and moisture, the muller is provided at the ends with closure plates 110 and 111, which may be provided with suitable apertures, not shown, to permit the uppers to pass in and out of the muller. As shown, the conveyor belt 102 is inclined downwardly as it emerges from the muller at each end, the entrance end being surrounded by a housing 112 and the exit end being surrounded by a housing 113 opening into the bottom of the muller tunnel. A steam trap is formed in the upper portion of the ends of the muller tunnel by this arrangement, since the steam tends to rise and will not escape through the openings so provided.

The conveyor belt 102 passes between the drive roll 101, described above, and an idler roll 114 located in housing 112. Intermediate its ends, the conveyor belt is supported by suitable rollers 115 and 116 `for the upper run of the belt, and 117 and 118 for the lower run of the belt. In between these rollers 115 through 118, the upper run of the belt is supported by slider rails 119, and the lower run of the belt is supported by slider rails 120, also shown in FIG. 5. The belt 102 may be of openwork construction, comprising strips of metal laid edgewise, each provided with a series of 90 bends intersecting bends in the adjacent strips, and hinged on wires passed through the intersecting bends in a manner well known to those skilled in the art, such that the resultant belt is a thick screen having approximately a 1 inch mesh and approximately 8O percent voids. Referring to FIG. 5, the upper slider rails 119 rest on a fine screen 121, which may be in the form of a relatively thin sheet of Monel metal perforated with approximately 625 holes per square inch, and having approximately percent voids, which is provided to prevent splashing from the water tank that might damage the uppers on the upper run of the belt 102. Screen 121 and slider rails 119 may be supported by angle brackets 122, a suitable number of which may be located along the length of muller 129. The lower run of belt 102 is supported by slider rails 120, which are spot welded to angle brackets 123, a suitable number of which are located along the length of the slider rails.

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A supply of water, which may be provided by a line 124 or by other suitable means, is maintained in the bottom of the tank to a level approximately indicated at 125 in FIG. 5 by an entrance end dam 126 and an exit end dam 127. As shown in FIG. 2, entrance dam 126 may be apertured for attachment of a drain pipe 128 and an overflow pipe 129.

As shown in FIGS. 2 and 5, a source of steam comprising perforated pipes 130 is provided in the water tank dened by the dams 126 and 127 and the bottom of the inner wall 108. As shown in FIG. 5, the perforations of pipes 130 are preferably directed downwardly and inwardly, to prevent undue cavitation of the water. The pipes may be secured in the bottom of the tank by any suitable means such as brackets 131 located at convenient distances along the bottom of the tank. As suggested in FIG. 2, the pipes 130 may be connected to a supply line 132, and the supply of steam may be controlled by any suitable device such as a control valve 133.

The steam supply pipe 130 provides a source of moisture for the muller, this source being equally effective in moistening both surfaces of the uppers placed on the upper run of belt 102. A second source of moisture, which is more effective in moistening the upper surface of the uppers, is provided by spray nozzles 134 disposed along the length of the muller tunnel. These nozzles 134 are connected by relatively short, rigid supply pipes 135 of relatively small diameter to an external supply of hot water, which will be described more -fully in connection with FIG. 6. As shown inV FIG. 5, the pipes 135 are directed upwardly, to cause a finely `divided mist of hot water to first rise in the muller and then fall gently on the uppers. As shown in FIG. 2, the pipes 135 are also directed longitudinally along the tunnel in oppositely disposed pairs, to provide an even distribution of the line spray along the tunnel. The function of the opposite longitudinal orientation of the nozzles is to prevent a net pressure drop from developing which would cause a net flow of gases through the muller, an obviously undesirable effect. In order that the moisture be directed toward variously inclined surfaces of the uppers, rather than falling vertically, we may provide in the muller enclosure a paddle wheel, as shown in FIG. 2, which may be rotated at an appropriate speed to cause turbulent agitation of the moist atmosphere in the muller.

We have found that it is extremely important to prevent condensed moisture on the walls of the muller from dripping down on the uppers. In many instances, the pigments used to color the leather will absorb water drops to cause stains which cannot be removed. In addition, such preferentially moistened spots have different lasting properties than the drier spots, leading to difficulty in later operations. In order to prevent this spotting from occurring, the upper portion of the inner shell 100 of the muller is made of triangular cross section, in the form of an inverted angle forming an apex 136, at the top, and preferably in the vertical plane of the longitudinal center line, of the dryer, and having outwardly inclined flat walls 137 and 13S which direct any condensed moisture along paths on the walls of the dryer to the water tank. This construction has the additional advantage of greatly reducing the volume of the muller tunnel, which minimizes the time required to change the process condition in the muller, making it possible to run uppers of different materials successively without undue delay. While the walls 137 and 138 may be made of any suitable material which will be impervious to water and `which is wet thereby sufficiently to retain the runlets on the surface, as noted above, these walls are preferably made of fiber glass lilled resin in a preferred embodiment of the invention.

Referring now to FIG. 2, the end plates 110 and 111 are provided with conduits 139 and 140 which run across their widths and are connected at one side, which is at a lower elevation than the other side, to auxiliary conduits 141 and 142 which direct the condensate back to the tank. In this manner, any dripping on the uppers as they enter and leave the muller is prevented.

As disclosed in the above-mentioned Patent No. 2,973,531, it is desired to produce an essentially saturated atmosphere in the muller at a temperature between 140 and 180 F. This atmosphere -is maintained yby the spray nozzles 134 and the steam supply line 130 as described. We have found that, as pointed out above, a desirable balance between the moisture in the upper and lower surfaces of the uppers can be provided by adjusting the ratio of spray to steam, and in accordance with our present invention we provide improved apparatus for controlling this ratio without introducing undesirable dripping from the spray nozzles. Referring now to FIG. 6, the control apparatus for the spray nozzles 134 of the muller 9 is shown. Referring now to FIG. 6, water from a suitable supply, such as a city water main, not shown, is supplied to an intake pipe line 143 in a conventional manner. Preferably, a conventional pressure regulator 144 is provided in line 143 to provide a constant input pressure, since otherwise the output spray pressure would be variable. To protect the spray control apparatus, it is also desirable l.to provide a filter 145 in the line 143. Following the lter 145 is the pump 104, which is driven from the motor 99 as schematically indicated in FIG. 2, or by a separate motor as previously mentioned. This pump raises the pressure to a suitable high value, such as 500 pounds per square inch. The output of the pump 104 is connected in parallel to spray supply line 146 and a relief line 147. Relief line 147 has connected therein a pressure relief valve 148 which is set to bypass the pump output to the overflow and drain line 129 when the pressure exceeds 500 pounds per square inch. Desirably, a check valve 149 is provided in the supply line 146 to prevent backflow. Downstream of the check valve 149, a pressure gauge 150 may be mounted to provide a visual indication of the condition of the apparatus.

A conventional wetting agent injector 151 is provided in the line 146 to inject a small amount of wetting agent to the water supply for surface tension control, optionally as desired. The injector 151 may be of a conventional type including a suitable pump, of the sort used in automatic washing machines.

Following the wetting agent injector 151, a pressure accumulator 152 may be included in the line to provide a-reservoir when the nozzles are open and to protect against surging. Following the accumulator is a first control valve generally designated at 153. This valve is controlled by a solenoid 154 conventionally shown as comprising an armature 155 and a control winding 156. We have shown control valve 153, which may be of any suitable commercially available design, in terms of a simple` convention adopted for its graphic simplicity. According to this invention, the valve is shown as a pair of blocks 157 and 158, the latter normally being held in the line by a spring 159, and being shown blank to indicate that it prevents ow. The block 157 is brought into the line when the solenoid 154 is energized, and permits flow in the direction of the arrow.

Following the rst control valve 153 in the supply line is a conventional immersion heating unit generally designated at 160 and provided with a temperature control generally designated at 161. By this means, the temperature of the water in the supply line is brought to the desired operating temperature of the muller. Connected between the iirst control valve and the spray nozzles 134 is a drain line 162 having at least one portion somewhat above the highest level of the water in the supply and provided with a second control valve 163 controlled by a solenoid 164. In accordance with the same convention as used to show valve 153, valve 163 is normally open, and is closed when solenoid 164 is energized.

Solenoids 154 and 164 are controlled over a common circuit including a lead 165 which extends to the wiper arm 166 of a ilow cycle timer schematically indicated at 167. This timer comprises a disc 168 which is mounted for relative rotation with respect to wiper 166 and for relative rotation with slight friction with respect to the support means, indicated schematically by the dashed line rectangle. A pair of adjustable stop members 169 and 170 are mounted on the periphery of the disc in desired positions which can be changed by manipulation of set screws securing the projections to the disc. The disc is also provided with a fixed projection 171 which is attached through a conventional linkage, not shown, but indicated schematically by the dotted line, to control a pair of contacts generally designed at 173.

Mounted on disc 168 is a conductive segment 174 which makes electrical contact with the wiper 166 over a desired portion, which may be 180, of the rotation of the wiper on the disc. Conductive segment 174 is connected over a lead 175 and a switch 176 to one terminal of suitable source of voltage such as a battery 177, the other terminal of which is grounded as shown.

Wiper 166 is driven by the shaft 178 of a suitable reversible alternating current motor 179, which has one winding reversibly connected over switch 173 and through a switch to a suitable source of voltage, such that motor 178 will be rotated in one direction or the other depending on the position .of switch 173. As shown, the motor 99 is interlocked with the motor 179 by parallel connection across its supply lines on the load side of the switch 180. Switch 180 is ganged for simultaneous operation with switch 176 by means of schematically indicated at 181, and whict are adapted for manual actuation in a conventional imanner.

In the operation of the apparatus of FIG. 6, lwhen means 181 is actuated to ` close switches 176 and 180, the motor 99 will operate to move lconveyor belt 102 and to drive pump 104. Assuming that the valves 153 and 163 are initially in the positions shown, closure of switch 176 will complete a circuit for the energizing of solenoids 154 and 164 to open valve 153 and close valve 163. Water under pressure will then be supplied to the heater and thence to the spray nozzles 134. This action will continue while wiper 166 rotates counterclockwise on disc 168 until the wiper 166 strikes the projection 169, driving the disc 168 counterclockwise and causing projection 171 to throw switch 173 lto its opposite position, While will reverse the motor 179.

The motor will then run in the opposite direction until wiper 166 moves 0E of control segment 174, which will deenergize solenoids 154 and 164, to cause Valve 153 to close and valve 163 to open. The opening of valve 163 will instantaneously relieve the pressure built up in the suplpy lines to the spray nozzles such that the spray will immediately shut off without dripping. It might appear at rst sight that the relative incompressibility of the water in a closed system would prevent after-flow at the nozzles. However, this is not the case, because at the high pressures employed in muller spraying, in accordance with our invention, the material of which the lines are made expands suiciently to provide a substantial reservoir of high pressure water, which would be relieved only gradually through the spray nozzles. Thus, the valve 163 performs an important function, and makes possible the control of the amount of water sprayed. It will be apparent that the relative proportions, as well as the overall period of the spraying cycle, can be adjusted by will by suitable movements of projections 169 and 170 on the disc 168. In combination with adjustment of the steam supply valve 133, these adjustments make it possible to exert control, over a wide range, of the mulling temperature and of the ratio of upper surface moisture to lower surface moisture absorbed by the mulled uppers.

Referring now to FIG. 4, the novel toe steamer 19 of our invention will next be described. As shown, the toe steamer 19 comprises an outer housing 182 secured to a suitable support 183, which may in turn be secured to lips 61 of guide channel 48, if so idesired. The toe steamer is provided with an angular inner plate 184 to direct condensate back to the box 18S and away from the last, which is assumed to be in position on last 75. The angles of pitch of the angular plate 184 must be so chosen that condensation will be carried along the surfaces of the plate and not fall from the surface. It has been found that the angles of the plates to the horizontal should not be less than 30 to 35 depending upon the characteristics of surface tension and viscosity in a given mulling atmosphere and temperature. Conveniently, the angle plate is bent to an angle of 90 and is arranged in the housing 182 symmetrically about the vertical. This arrangement provides a 45 pitch. A gutter 184C is provided at the forward edge of the plate 184 to collect yand drain away the condensate. Within the toe steamer, a steam box 185 provided with an apertured lid 186 encloses a steam pipe 187 which is located on one side of a bale 188. The steam box 185 is partly filled with water, as indicated in the drawing, to cover the pipe 187. The pipe 187 is perforated to allow steam to escape in a baffled manner which will prevent spraying, and so as to pass through the water in the steam box 185, to insure that the steam is Wet and not dry, since hot dry steam might injure the uppers. Referring to FIG. l, the apertures in pipe 187 may be graduated along the length of the toe steamer 19 such that a major proportion of the steaming is done in the first portion of the steamer, such that all of the toe-s are adequately steamed by the time that they reach the rst bed lasting station 20 in FIG. l. Less steam is provided in the remainder of the apparatus, so that the stage of condition-ing reached at the first bed lasting station 120 is maintained without change until the asts reach the final bed lasting station 20. In addition to the graduation of the holes in the steam pipe 187, an additional steam pipe or pipes may be provided in the first portion of the steamer and controlled by individual valves, not shown, to obtain a suitable balance between the conditioning effected by the two portions of the steamer.

Referring now to FIG. 7, we have shown (somewhat digrammatically) a typical cross section through the upper dryer 22 of our invention. As shown, the dryer 22 comprises an inner shell 189, an intermediate shell 190 and an outer shell 191. The space between shells 190 and 191 may be filled with insulation 216 of the type employed in the muller, and the shells themselves may be made of the Same material as employed in the muller. The lasts 75 conveyed by the conveyor 55 through guide channel 48 will pass through the dryer, such that the last is approximately centered, although the center line of the guide channel 48 is displaced somewhat, as shown. The dryer is supported by plates 192 bonded to blocks 193 formed integral with the inner shell 189. Plates 192 are in turn secured to channel 48 through intermediate members 194 which are welded together zand provided with lugs mating -with the lips of the guide channel 48 as sufciently shown in FIG. 7.

A plurality of elongated heaters 195 are disposed about the inner periphery of the inner shell 189 as shown, such that they irrafdiate the shank of the uppers without appreciable heat being applied to the insole portion of the lasted shoe, or to the outsole lcarried on the side of conveyor 55. Each of the heaters 195 may comprise a conventional quartz heating unit including a reflector 196 and a heating element 197, although any other suitable conventional heating element may be employed if so desired. Referring to FIG. 1, these heating units are divided into three sections 23, 24 and 25. The group of heaters 23 are operated at a relatively high temperature, since a large `quantity of heat can be absorbed in elevatingthe temperature of the moisture without damage to the uppers through overheating. The intermediate set of dryers 24 is operated at a lower temperature, which ideally is selected to just maintain a constant drying temperature for the uppers to remove the bulk of the moisture. However, in practice,the variability Qfizes, colors, patterns, leathers and other factors recommends a setting of this second group below the ideal and thus warranting the provision of the third group of heaters 25. The last group 25 `of heaters is set at a relatively low temperature which is so determined that the uppers are heated little beyond the point at which their surface temperature begins to rise above the constant drying temperature which is maintained as long as they have moisture at the surface. Thus, this unit may be such that, while driving out the last of the moisture, it Iwill prevent the uppers from rising to a temperature that might be harmful to the finish or the leather.

Referring again to FIG. 7, constant circulation of air to promote uniform drying is maintained in the dryer 22 by one or more axial fans 198 mounted on the upper portion of the dryer and discharging air upward through an aperture 199 which is elongated and extends along the top of inner shell 189. Cooling air enters the drye1 through the ports 201 spaced at appropriate intervals along its bottom, the ports 201 being, in effect, continued through the space between the shells 189 yand 190 by longitudinal barriers 802. Similar barriers 800 block the interspace between the same shells adjacent the top of the dryer. The drying of the llasted shoe is accomplished by radiation from the spaced heaters, and the passage of cooling air through the dryer serves two purposes. It prevents overheating of the sole member 55 during normal operations of the dryer and also prevents overheating of the lasted shoe in the event of a stoppage `of the conveyor, it being understood that when the conveyor stops, the quartz heaters are automatically turned off. Otherwise the lasted shoes would be exposed to the radiant heat energy for an excessively long time. The fans 198, of course, continue to operate whenever the Vconve-yor is stopped. There may not be any moisture buildup which would cause condensation in this system, because of the temperature in the unit and the relatively small amount of moisture in the shoes, at least unde-r the usual length of run. However, if condensation becomes a problem it may readily be alleviated by permitting makeup air to leak around the guide channel 148, and by providing for the removal of the moist air through ports 202, which can be controlled by suitable adjustable baffles 203 as suggested in FIG. 7.

Referring now to FIG. 8, the activator unit 39 of our invention comprises a shoe bottom activator portion 41 having a suitable housing 204 connected by a suitable support diagrammatically indicated at 205 connected to the lips 61 of the guide channel 48. A housing 206 for the outsole activator 40 may be connected either to the lower lips or the other side lips of the guide channel 48. As here shown, it is connected to the bottom lips 63 by means of a suitable fitting 207 sufficiently illustrated in 208.

Turning first to the outsole activator unit 40, the sole indicated by dotted lines is irradiated by a heating unit 45, here shown as comprising an elongated enclosure 208 provided with a double reflector 209 and secured to the housing 206 by any conventional means through intermittent heat insulation 210, and a pair of elongated quartz heating bulbs 211 mounted within the reflectors.

Referring now to shoe bottom activator portion 41 of the activator 39, this comprises a plurality of elongated quartz heating units 42, 43 and 44, which operate preferably at a lower temperature than the outsole activating unit, and which are secured to the upper housing 204 by means of` suitable slotted brackets 212, 213 and 214 for adjustment in the direction of the arrows as shown. Unit 42, as shown in FIG. l, extends substantially the length of the activator and performs the most demanding activating operation, that on the forward portion of the overlasted margin. Activator unit 43 is shorter, and performs the less demanding operation of conditioning the shank of the insole. Unit 44 may be quite short, since it need only condition the cement on the breast of the heel.

It will be apparent that in the operation of the cement activator of FIG. 8, the heat activatingoperation is elfi t' 13 ciently and rapidly performed, without any risk of overheating portions of the shoe or sole which require less heating treatment than the other portions.

Referring again to FIG. 1, where it is desired to make shoes having synthetic plastic uppers, for example of polyvinylchloride or the like, certain variations in the process of our invention may be made. Specifically, the plastic does not require moisture for last conditioning, but is conditioned by heat alone. Moreover, these uppers are in some cases as susceptible to staining by water spots as are leather uppers. However, the plastic uppers are frequently lined with cloth or other material which is more easily lasted after mulling with both heat and moisture. In order to adapt the process of our invention to meet these requirements, the plastic uppers are first heated in the vinyl preheater 12 shown schematically in FIG. l. This preheater can be of any conventional design, suitable to perform the function of heating the plastic uppers to a temperature above the muller temperature, so that condensation on the uppers will not occur in the muller. The preheated uppers are then placed in the muller 9 lining side uppermost, so that the linings may be mulled in the usual way with heat and moisture, the latter being supplied primarily by the spray nozzles 134, While the plastic uppers will be heated, but not moistened. The rest of the process may be carried out in the same way as described above for leather uppers.

As previously stated, it is an important feature of the improved method of shoe manufacture to subject the uppers to rapid drying after mulling to remove the excess moisture therefrom as quickly as possible. Due to the rapid turn round of lasts in the system of the invention moisture may remain in the last. This may not only affect the rapid drying of the uppers but also the shape and/or dimensions of the last. According to a further aspect of the invention means are provided for preheating or warming the lasts before the uppers are placed thereon. Although not shown in the drawings, the last warm-ers or preheaters may conveniently 'be provided below the muller to direct heat on the lasts as they are brought along on the conveyor chain 70 (FIG. 2). Any suitable heating means may be provided for this purpose.

Having thus disclosed our invention what we claim as new and desire -to secure by Letters Patent is:

T-he process of mulling shoe uppers comprising the steps of conveying the uppers through a tunnel having a Water saturated atmosphere at a temperature between and F., collecting the moisture condensing on the walls of the tunnel to prevent it from dripping on the uppers, periodically spraying a tine mist of water at the temperature of the atmosphere of the tunnel upwardly in the tunnel to rise and then fall on the uppers, and abruptly and positively shutting off the spray between sprayings.

References Cited bythe Examiner UNITED STATES PATENTS 2,206,275 7/ 1940 Woodberry 12,-142 2,940,094 6/ 1960 Bromtield 12e-1 2,973,530 3/1961 Bromeld 12-142 2,973,531 3/1961 Bromfield 12-142 3,055,026 9/1962 Gulbrandsen 12-16.4 X

JORDAN FRANKLIN, Primary Examiner.

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