US2549981A - Double activation with conditioning for sole attaching - Google Patents

Description

April 1951 M. MAESER ET AL 2,549,981

DOUBLE-ACTIVATION WITH CONDITIONING FOR SOLE ATTACHING Filed Sept. 27, 1949 9 Sheets-Sheet l 26 1 40 i zz [nven tors M'eth Maesez" Rabh E HobbS Jn B r z'rA may .\w

April 24, 1951 M. MAESER ETAL 2,549,981

DOUBLE-ACTIVATION WITH CONDITIONINGFOR SOLE ATTACHING Filed Sept. 27, 1949 -9 Sheets-Sheet 2 4 fiwen tom 47 Mz'et/z Maeser PaZp/z E. Hobbs Jr:

April 24, 1951 M. MAESER ET AL DOUBLE-ACTIVATION WITH CONDITIONING FOR SOLE ATTACHING 9 Sheets-Sheet 3 Filed Sept. 27, 1949 lnven tors .Mz'eth Maeser' Ranh EHabbs' J n m r 0 u A .P w m U B April 24, 1951 M. MAESER ET AL 2,549,981

DOUBLE-ACTIVATION WITH CONDITIONING FOR SOLE ATTACHING Filed Sept. 27, 1949 9 Sheets-Sheet 4 Mz'ezh Maeser' Rqlph E H0663 Jr. 5' zhz'r 1 e I 9 H April 24, 1951- M. MAESER ET AL $549,981

DOUBLE-ACTIVATION WITH CONDITIONING FOR SOLE ATTACHING Filed Sept. 27, 1949 9 Sheets-Sheet 5 2,549,981 DOUBLE-ACTIVATION WITH CONDITIONING FOR SOLE ATTACHING Filed Sept. 27, 1949 April 24, 1951 M. MAESER ETAL 9 Sheets-Sheet 6 l v in! llll April 24, 1951 M. MAESER ET AL 2,549,931

ACTIVATION WITH CONDITIONING FOR SOLE ATTACHING DOUBLE- Filed Sept. 27, 1949 9 Shee cs-Sheet 7 0 w M M m 0% %/I@ W .N m Wm HEP-Em m -EJIB w 3 M MW m I -i w ,6 I W 1 K m m I Mz'et/L .Mmsuser Ralph E Hobbs r:

M. MAESER ETALj 2,549,981 DOUBLE-ACTIVATION WITH CONDITIONING FOR SOLE ATTACHING April 24, 1951 '9 Sheets-Sheet 8 Filed Sept. 27, 1949 Yr i ln ven tors Mezh Maeser' Raoh E3 Hobbs Jr: By Zia! April 24, 1951 I M. MAESER ET AL 2,549,981

DOUBLE-ACTIVATION WITH CONDITIONING FOR SOLE ATTACHING Filed Sept. 27, 1949 9 Sheets-Sheet) 9 I Thermosla! fl r link Inventors 94 Mz'ezh Maeser Patented Apr. 24, 1951 UNITED STATES PATENT OFFICE DOUBLE ACTIVATION WITH CONDITIONING FOR SOLE ATTACI-IING Application September 27, 1949, Serial No. 117,966

This invention relates to apparatus for conditioning and treating shoe materials which are to be vadhesively attached. More particularly, the invention is concerned with the provision of means for preparing soles for attachment to shoe bottoms by rubber-like cement. While especially useful in facilitating such attachment when the shoe materials are of leather and the adhesive is readily heat-activatable only at rather high temperatures, it will be understood that utility of the present invention is not so restricted, nor is it necessarily limited to sole attaching.

As pointed out in United States Letters Patent No. 2,367,629 granted to Jan Teppema, certain adhesive compositions such as those comprising butadiene-acrylonitrile copolymer with a toughener therefor may be advantageously employed to secure shoe parts together and maintain them in very tight relation. In contrast with neoprene base and other synthetic rubber-type cements, not only are these compositions found to be peculiarly effective in adhesively attaching a variety of materials coated therewith, but, unfortunately, they also are found to have the characteristic of being activatable only at temperatures considerably above those at which the neoprene base types and some other adhesives are heat activatable. It has been learned that an especially beneficial property of the butadiene-acrylonitrile type cement in shoemaking is its ability to retain L its capacity for being heat activatable after prolonged drying times such as a month or more. But, for activation of this type cement within a short period of time convenient to shoemakers (about 15 seconds for soles) and corresponding With the production rate of certain shoe machinery, experience reveals that the requisite high temperatures (about 400-450 F.) are ordinarily damaging and even destructive to many leathers and other shoe materials unless appropriate protective measures be taken. There is, moreover, a tendency for the cement activatable only at high temperature to set more rapidly when removed from the activating heat, and, lastly, the finding of a satisfactory solution to the activation problem is made more difficult by the fact that such high temperatures frequently tend to induce shrinkage and distortion of the heated surfaces.

For quicker and better attaching results, each of the two surfaces to be joined should be roughened and bear a cement film. Also, the sole leather or other material should not have entirely lost its moisture content; that is, it should be in a pliable condition enabling it to conform 10 Claims.

and adhere closely to the curved shoe bottom or other contour. Excessive moisture content in a sole, while imparting pliability, will, however, result in spotty and unacceptable edge and bottom characteristics upon application of activating heat. For cement attaching different materials permanently, therefore, it Will be appreciated that a preparatory operation with an appropriate apparatus having control of temperatures and moisture is highly desirable.

Having due regard for the above considerations and realizin that, for any adhesive surface, an evenly distributed activation is important, the present invention embodies two-Way activation. This is to say that the influence of the same source of activating heat is simultaneously di-' rected toward the sole cement and shoe bottom cement, for example. By means of this principle, lower activating temperatures, better bond strength over longer cementage, that is age of .cement after application, and reduced danger of hydrolyzing the work are results obtained at lower operating cost.

In view of the foregoing, an object of the present invention is to provide an improved means for more rapidly and satisfactorily preparing for attachment work pieces having adhesive thereon that is readily activatable only at temperatures which are detrimental to them.

In accordance with this object, and inone aspect of the invention, a feature resides in preparing a sole for cement attachment to a shoe bottom by directing a current of warm moist conditioning air against one face (the grain side, for example) of the sole both before and then while the influence of hot activating fluid is simultaneously directed upon its cement coated attaching face and the coated shoe bottom.

Another feature of the invention relates to the provision of convenient and novel apparatus for practicing the method just mentioned comprising means for supporting a sole in a current of warm moist air, means for emitting hot dry air against the cement coated portions of said sole and its shoe bottom while supporting the latter, and mechanism for relatively moving one of said means with respect to the other so that said coated portions may jointly partake of the activatin heat while said sole is being suitably tempered in moist air.

In an alternate aspect, a still further feature of the invention is the provision of novel activating means which may be advantageously employed, if desired, in lieu of the just mentioned hot dryair medium, said means comprising a conformable heating unit containing temperature-controlled activating fluid and adapted to contact all, or substantially all, of the confronting cemented surfaces simultaneously.

With the above object and features in view, the invention will now be more particularly described with reference to the accompanying drawings, in which Fig. 1 is a perspective view of an illustrative apparatus embodying the present invention;

Fig. 2 is a view partly in section and on a larger scale of an upper portion of the apparatus as viewed from the front of the machine (or from the left in Fig. 1) when subjecting a shoe and its outsole to double activation, preparatory to sole attachment;

Fig. 3 is a side elevation, partly in section, of the air heating and distributing mechanism shown in Fig. 1, the shoe sole support being shown in its lowest position;

Fig. 4 is a plan view of a portion of the apparatus seen in Figs. 1 and 3;

Fig. 5 is a perspective of a shoe and its outsole on their respective supports at an initial stage of treatment;

Fig. 6 is a perspective of the shoe and sole seen in Fig. 5 at a subsequent stage of their treatment;

Fig. '7 is a vertical section taken across the toe portion of the shoe and sole viewed in Fig. 6, and illustrating double activation during sole conditioning;

Fig. 8 is a perspective of an alternate heat activating unit which may be substituted in the apparatus for the dry hot air mechanism;

Fig. 9 is a plan view of the alternate form of heat activator seen in Fig. 8;

Fig. 10 is a front elevation of the alternate activator when operating on both sole and shoe;

Fig. 11 is a sectional view corresponding to Fig. '7, but illustrating the conformability of the alternate activator to the contours of cemented surfaces to be attached;

Fig. 12 is a rear elevation of the pump and motor mounting; and

Fig. 13 is a wiring diagram of the electrical sysstem for control of the apparatus.

For simplicity the illustrated apparatus is in the form of a single station machine. It will be understood that multiple station machines for treating rights and lefts would be of substantially similar construction except that the respective shoe and sole supports would be vented in a pattern corresponding generally to the right and left cemented margins to be activated. As will become apparent, however, unless it is desired to prepare more than one shoe at a time for sole attaching, duplex construction is unnecessary when the alternate form of heat activator is employed, as hereinafter disclosed.

Referring to Fig. 1, the apparatus is preferably supported by a rectangular boxlike frame If) in which is fixedly mounted shelves [2, I4 and I6 for purposes later to be explained. Detachably supported in an aperture formed in the top of the frame ID by brackets l8 afiixed thereto is a hollow metallic support for a shoe. This stationary support 20 is of a shape such that its upper surface 22 has a longitudinal contour complemental to the cemented shoe bottom to be activated. For operating on shoes differing considerably in bottom contour, other and more suitably formed supports 20, not shown, may be secured to the brackets 18, or the accommodation of shoe bottoms by a single support may be improved and broadened, as for example, by employing a shoe support comprising two or more hollow sections consecutively hinged together.

The support 20 has a lower surface 24 (Fig. 2) preferably approximately parallel with the surface 22 for reasons which will become apparent. The surfaces 22 and 24 are provided with perforations or hot air emission ports 26 (Figs. 5, 6, '7 and 8) which are so spaced as to generally define and confront the usual cemented margins of the shoe bottom and attaching face of the sole which are to be activated for attachment. Spacing elements 28 secured to both surfaces 22 and 24 serve to separate the cement film therefrom, thus assuring even dispersion of air blown through the ports 26.

Means are provided for directing into the shoe support 20 a steady current of highly heated dry air. While any suitable mechanism for accomplishing this may be employed, the preferred arrangement (Figs. 1, 3 and 4) utilizes a blower 30 (Fig. 3) driven by an electric motor 31 (Fig. 13). The blower is secured to one end of a hollow insulated cylinder 32 which is aflixed to a rearward portion of the frame I0. Air taken into the blower 38 at its inlet 34 is forced past an electric heater element 36 in the cylinder 32 to have its temperature raised. A two-way duct 40 connected to the other end of the cylinder 32 intro duces the dry heated air into both the toe and shank portions of the support 20.

In juxtaposition beneath said shoe support 20 is a sole support 42 mounted as will now be described (Fig. 2). Supported from the top of the frame It) and disposed diagonally of said supports is a pair of vertical guide rods 44, the latter being respectively secured to bosses 45 integral with the frame by bolts 46 (Figs. 2 and 3). The shelf I6 is supported by bolts 41 received by the lower ends of the rods 44. A moisture generating tank 48 rests on the shelf [6 and has a drain plug 50 accessible through the latter. The sole support 42 includes in its upper portion a screen 52 substantially parallel with surfaces 22 and 24 of the support 20, and the screen is overlaid with foraminous material such as a felt pad 54. Depending sides of the sole support 42 are arranged for telescopic movement relatively to the tank 48. The top of the latter is provided with a strip of rubber 56 extending for edgewise engagement with said sides to prevent the escape of vapor at this junction. The lower limit of movement of the sole support 42 is fixed by stops 58 (Fig. 3) secured to the rods 44, a bracket 6|! afiixed to the support 42 having sleeves 62 slidable on the rods 44 between said stops and the bosses 45.

For raising or lowering the sole support 42, one link 64 (Fig. 1) of a toggle is pivotally connected to the bracket 60. The other link 66 of the toggle constitutes an arm of a bell crank 68 pivotally connected to a crossbar of the frame [0. A treadle 10 pivotally mounted near the base of the frame It! is connected to the bell crank 68 by a vertical link 12.

Water from a water main is supplied to the tank 48 by an inlet pipe 14 and via a valve 16 (Fig. 2). The latter is automatically regulated by means of a conventional float 18 so as to maintain a suitable water level in the tank. The water is heated by means of a heating unit extending across the lower part of the tank, the unit being connected by wires in a conduit 82 to an electric control box 84. A thumb head 88 mounted on the box 84 controls a thermostat 86 for regulating the heating unit 80 and the temperature of the water.

' For supplying warm moist air to the sole support 42, air is admitted near the bottom of the tank 48 by being forced under pressure through a perforated pipe 90. This air pressure is derived from acompressor 92 driven by a motor 94, both compressor and motor being mounted on shelf H as best seen in Fig. 1 2. Before being conducted into the pipe 98 via a hose 96, the compressed air is preferably led through a filter 98 mounted on the shelf Id to eliminate oil particles or other extraneous matter. Tubing Hi0, connected to a valve 38 for a purpose subsequently described, is coiled about a portion of the heater 36 and is arranged to conduct compressed air directly from the pump 92 to the low portion of the felt pad 54 where the warmed air may be blown crosswise thereof.

A main switchl02 (Figs. 1 and 13) is' provided at the front of the apparatus and, when closed, a single auxiliary switch I04 may be thrown to energize the heater and blower relays and the air compressor motor 94'. A variable transformer I06 mounted on the shelf I2 is provided with a dial and adjusting knob I 08 (Fig. 12) by which to set the desired temperature of air to be delivered by the blower so. 7

In an alternate form of the apparatus a dif ferently constructed shoe activator support or receptacle generally designated I I0 (Figs. 8 to 11,

inclusive) is substituted for the hollow support 20. Referring to Fig. 8, the activator support I I0, secured as by brackets H2 to the top of the frame I0 and in juxtaposition to the sole support 42, comprises a generally rectangular frame H4 having a longitudinal curvature corresponding to that of a shoe bottom. The top and bottom of the frame H4 are respectively covered by pliant sheets I It firmly anchored against leakage as by strips H8, H9 and screws I (Fig. 11). The material of the sheets H6 may be selected from any nonleaking fabric having the characteristics of being a good heat conductor, able to withstand high temperature without breakdown, and not inclined. to pick up activated cements. A sheet material found to be unusually satisfactory for this purpose is afabric of spun glass impregnated with synthetic rubber. A receptacle I22 serves as an inlet and overflow reservoir for liquid filling the support H0. The liquid to be used is preferably an oil having a flash point of 500 F. or over. A heater I24 (Fig. 11) is immersed in the oil and arranged in a loop having itsterminals respectively connected to wires leadingto the variable transformer I05. It will be apparent that the heater unit I24 supplants the air heating mechanism otherwise associated with the shoe support 20.

In preparing an outsole O for attachment to the bottom of a shoe S by means of the apparatus of this invention, adhesive will first have been applied as a film A to a marginal portion of both the shoe bottom S and the attaching face of the sole 0. It may be assumed for present purposes that a rubberlike cement activatable only at rather high temperatures is being employed for better bonds and then, as is customary, the coated worl: pieces have then been allowed to age for as much as a day or longer. The operator of this apparatus may also operate a sole attaching machine or serve as an assistant to the sole attacher. He will close switches I02 and I04 and. then adjust the water thermostat control 88 to provide a vapor temperature of about 170 F. and the variable transformer knob I08 to provide an air flow temperature to the shoe support 20 of Cal With the shoe support 20 spaced from the sole support 48, as seen in Fig. 5, the operator places the shoe bottom S on the surface 22, and the sole 0 is placed grain side down on the felt pad 54.. Then, either by stepping on the treadle I0 or by depressing the bell crank. 68 by hand, the op erator raises the sole support 42 to bring the flesh side of sole 0 in close proximity to the surface 24 and under the activating influence of the hot, dry air. No special efiort is made at this stage of operations to clamp the sole under any high molding pressure. Thus, while the shoe bottom is being activated by air escaping from the upper perforations 26,. the sole adhesive is also being activated by hot, dry air from the lower perforations 26, and the grain side of the sole 0 is being conditioned by the warm moist air directed thereagainst through the felt pad 54. Being thus rendered somewhat inert and pliable by the circulating moisture the sole will more or less assume the contour of the sole support 42. It is important to note that the warm moist air serves bothto prevent burning or bydrolyzing of the work: pieces and to assure that they will: still be in moldable and activated condition some moments later when removed to a sole attaching machine.

wetness or excess moisture causing spotty or otherwise unacceptable condition on the sole tread surface is normally eliminated by the pad 54. When steeply curved shoe bottoms are being worked. upon. or the apparatus has been steadily employed on many shoes an excess wetness may accumulate along the low portion of the pad 54.. To guard'against this the valve 38 may be opened so that the tube I063 delivers a stream of air heated somewhat by the heater 36 and so vapor-ices the excess moisture in this region.

In about fifteen seconds for ordinary leather, or for longer periods at lower temperatures, if more convenient, the operator may release the treadle 10 or cell crank. 68 to separate the sole support 42 from the shoe support 20. The activated cement surfaces are ready for adhesion and the work pieces may be removed from the machine, spotted on one another, and delivered to the sole attaching machine for the application of suitable pressure. Transfer to this machine need not be made hurriedly, however, as the activating effect will be prolonged by the vapor treatment, and the sole is in no danger of grain cracking when the attaching pressure is applied.

The manner of using the alternate heat activator H0 in lieu of the support 20 is essentially as just described for operating the latter. The activator H0 is frequently found especially convenient in that an operator will not be subjected to uncomfortable operating temperatures although the oil is kept at 400450 F., and the operating cost may be somewhat lower without slowing down the attaching process. Also, since the activator H0 is conformable and will be in intimate contact with the contours of any coated surface to be attached, items other than soles and shoes may be placed thereagainst for double activation during conditioning.

Having thus described our invention what we claim as new and desire to secure by Letters Patent of the United States is:

1. Apparatus for conditioning a sole and simultaneously activating adhesive on said sole and a shoe bottom, said apparatus including a sole support arranged for contact with warm moist air, and a heating unit in juxtaposition with said sole support having one side shaped to conform with a sole thereon and another side shaped to conform with a shoe bottom.

2. Apparatus for preparing a cemented sole and shoe bottom for adhesive attachment to one another comprising a perforate support for said sole having the general contour of said shoe bottom, a heat activating unit in juxtaposition with said sole support and having opposite surfaces conformable with said general contour, means for directing warm conditioning vapor about said support, and means for directing heated fluid into said unit. 7 3. Apparatus for preparing one cemented shoe part for adhesive attachment to a second comprising a conditioning chamber, a vapor generator operatively connected therewith, a support for said first part movable in the chamber and having a surface shaped to conform with the attaching face of the second part, and a two-way heat activating unit disposed for intimate engagement with the attaching face of said first part on said support, said unit also serving as a conformable support for said second part.

4. Apparatus for conditioning a sole and simultaneously activating adhesive on said sole and a shoe bottom, comprising a conditioning chamber, means for generating warm vapor in said chamber, a perforate sole support for exposing the sole to the vapor in the chamber, a heating unit adjacent said chamber having opposite surfaces respectively adaptable to conform with said sole and shoe bottom, and means for relatively moving the sole support and heating unit together and apart whereby sole tempering may be effected during two-way activation by said unit.

5. Apparatus as set forth in claim 4 further characterized in that controls are provided for independently governing both the conditioning temperature within said chamber and the activating temperature of said heating unit.

6. Unitary apparatus for activating a cemented sole and shoe bottom while conditioning said sole, comprising a sole support including a surface complemental to said shoe bottom, means for moving said support with a sole thereon while the latter is in contact with warm moist air, and a heating unit mounted in the path of said sup- 8 port having activating faces also complemental to said shoe bottom, one of said faces being arranged to cooperate with said surface during contact with said sole.

7. A heating unit for activating the cement coated portions of two work pieces to be adhesively attached comprising a receptacle for oil, frame portions of the receptacle generally defining the contour of the attaching faces, means for controlling the temperature of the oil, and pliant heat-conducting coverings for the opposite sides of said receptacle, said coverings being in contact with the oil and respectively conformable to an attaching face.

8. A heating unit as set forth in claim 7 further characterized in that said coverings respectively comprise a fabric of spun glass impregnated with synthetic rubber.

9. Apparatus for preparing a leather part of a shoe for adhesive attachment, comprising a formed support engageable with a non-attaching face of the part to be treated, means for subjecting the part to warm moist air, a conformable heat activating unit in juxtaposition to the support, and means for relatively moving the unit and the support whereby the attaching face of the part is located in proximity to the unit and thereby activated during conditioning of the remainder thereof.

10. Apparatus for preparing a cemented sole and a cemented shoe bottom for adhesive attachment, comprising a formed sole support, a twoway heat activating unit arranged and adapted to treat the shoe bottom, means for directing warm moist air about the sole on said support but not to the shoe bottom, and means for relatively moving said support and unit whereby the activating effect of the latter is also influential in the vicinity of said support.

MIETH MAESER. RALPH E. HOBBS, JR.

REFERENCES CITED UNITED STATES PATENTS Name Date Borge Mar. 14, 1933 Number

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