US2229224A - Electric activation of toe-lasting cement - Google Patents

Description

Jan. 21, 1941.

5. ROGERS ELECTRI Q ACTIVATION 0F TOE-LNSTING CEMENT Filed April 12, 1940 Patented Jan. 21, 1941 UNITED STATES 2,229,224 ELECTRIC ACTIVATION F TOE-LASTING CEMENT Walter S. Rogers, Falsmouth,

Mass., assignor to United Shoe Machinery Corporation, Borough of Flemington, N.

' Jersey J., a corporation or New Application April 12, 1940, Serial No. 329,282

6 Claims.

This invention relates to machines for lasting shoes by means of cement and more particularly for activating the lasting cement around the toe end of a shoe, by means of a high-frequency electrostatic field.

In cement lasting it is common to provide a film of adhesive between the margin of the insole and the overlasted margin of the upper and this cement may be of the thermoplastic variety insole.

Accordingly, an object of this invention is to provide apparatus for the activation of the last- 'ing cement by means of a high-frequency electrostatic field, thus enabling the heat to be produced directly in the cement and at any desired time in the cycle or the lasting operation.

One particular application of the invention as illustrated herein concerns the activation of the cement in shoes being treated in a power-operated toe-lasting machine, and takes advantage of the fact that shoes which are to be lasted in one of these machines are frequently constructed upon lasts having metal toe plates attached to the bottom of the lasts. As illustrated, therefore, such a toe plate is used as one of the electrodes, while an element of the machine located outside the shoe is utilized as the other electrode. The intended purpose will be accomplished if this machine element is in such a position that the field setup between it and the toe plate includes the him of cement in the shoe. Consequently, the

wiper plates of the lasting machine have been employed for this purpose and are connected to J one side or an oscillator which forms the source of electricity. The other side of the oscillator is connected to the toe plate by locating pins which pass through apertures in the insole to engage suitable recesses in the last and which at the same time engage the toe plate.

These and other features of the invention will best be understood from a consideration or the following specification taken in connection with the accompanying drawing,'in which the heat through the leather of the upper or they Fig. 1 is a vertical-section through theshoe-" engaging portion of a toe-lasting machine to which the invention'has been applied;

Fig. 2 is a detail view showing the position of the parts at the completion of the lasting operation;' I

Fig. 3 is a plan view showing the overlasted shoe upper held in position by wipers; and

Fig. 4 is a transverse section through the toe end of a shoe with the parts of the machine in the positions illustrated in Fig. 2. 1

The invention has been applied to a machine of the type illustrated in Letters Patent oi the United States No. 2,224,146, granted December 10, 1940, upon the application of F. C. Eastman for improvements in Lasting machines, and only 15 so much of the machine has been shown herein as is necessary toa description of the present invention.

The machinevis shown as operating upon a shoe built upon alast L which is provided with 20 a metal toe plate P. This plate is provided with a pair of metal sockets i0 and is flush with the bottom of the last, lying beneath the insole I over which the upper U is to be lasted. A shoe S will be located in the machine by raising the 25 bottom of the insole into engagement with a plate l2 of insulating material, such as Textolite or the like, which is supported through interposed parts upon a plunger ll vertically adjustable in the frame iii of the machine by means of a threaded stop It. The plate I2 must be. of a size suited to the 'size of the shoe to be lasted and, accordingly, it is made removable for exchange with plates of difierent size and is provided with an apertured stud 20 received in a socket in a metal member 22. The member 22 comprises top and bottom flanges 23 and 25 (Fig.

4) interconnected by a vertical web in which there is slidably mounted a sprin plunger 24 (Fig. 1) which cooperates with the stud 20 to lock the plate I2 in position on the carrier. The member 22 is attached by screws 26 (Fig. 2) to the bottom or a block 28 of insulating material which, in turn, is attached by'screws 30 to a flange 3| on the lower end of the plunger 14.

Shoe locating pins 34, such as have been employed in the lasting machine of the Eastman patent No. 2,224,146, are secured in the member 22 and extend tl-rough apertures 36 (Fig. 4) in the plate l2 and apertures 38 in the insole I into contact with the sockets it which may be made a part of the toe plate P. The high tension side of an oscillator (not shown) is connected. to the member 22 by a lead 40, and the locating pins 34 both locate the shoe inproper angular position in the machine and serve to convey the electric current to the metal toe plate P upon the bottom of the last.

In carrying out the lasting operation, the upper U is first drawn upwardly and outwardly with respect to the shoe by means of grippers in a carrier 52 which is pivotally supported at 54 at the end of an arm 56 carried on a rod 58 so attached to the frame of the machine that the arm 56 may swing around the center of the rod. During this lasting operation the toe end of the shoe is held up against the locating plate It by means of a toe rest 42 having a pad 44 which overlies a rigid member 46. The toe rest is raised automatically, substantially at the beginning of the operation of the machine, and in connection with a,heel band (not shown) serves to clamp the shoe in position in the machine.

It will be understood that both side and end grippers 50 are provided, but that only the end gripper is herein illustrated. Up-and-down movements of the gripper carrier 52 are imparted through a cam-operated link 60, and in-and-out swinging movements of the gripper carrier are imparted through a cam-operated link 62, this arrangement being more fully described in Letters Patent of .the United States No. 2, 0,8 6. granted 'June 6, 1939, upon the application of F. C. Eastman et al.

The margin of the toe end of the insole is heldbetween the carrier 14 and the flange 3| on the.

lower end of the plunger I4. It is also supported by the arms of a yoke 18 pivotally mounted on the plunger l4 and having an upstanding portion providing a shoulder 80. The holddown member 10 is held in engagement with the insole by means of a spring 82 extending between the upper end of the carrier I4 and a pin on the frame of the machine.

The machine is also provided with wipers 90, supported in wiper carriers 92 and arranged for movement toward the toe end of the shoe, to engage the side of the shoe and then to upwipe the upper U. After this the wipers 90 are carried in over the insole I against the upper as it is tensioned by the grippers 5i! and similar side grippers (not shown). These grippers are released at the desired point in the cycle by the action of a cam-operated lever 94 on a plunger 96 sliding within the gripper carrier 52. It will be noted that the lower outside margin of the holddown member 10 is provided with a bevel 98 so that said member in cooperation with the wipers 90 serves as a retarderto cause the upper to be wiped more tightly and smoothly'inward over the insole. During the inward movement of the wipers the grippers are permitted to swing inwardly toward .the shoe, and in order that there may be no interference between the holddown 10 and the grippers, the holddown is lifted out of their way. Thus, as the holddown is raised by the engagement of the wipers with the beveled surface 98, the shoulder 80 on the yoke 18 is raised to a point where it will be engaged by a notch I00 in a bar' I02. This bar held down engagement with the insole.

against a surface I04 on the yoke 18 by means of a spring I06 and is moved laterally by means of a cam-operated arm I08 to raise the holddown against the tension of the spring 82.

The arrangement of the machine is such that it comes to rest after the upper has been completely wiped in and the wipers 90 have been depressed to hold the overlasted upper firmly in At that time, for example, power is supplied to the electrodes either automatically or manually byway of the lead 4|! connected to the positioning pins 34 and a lead H0 here shown diagrammatically as connected directly to one of the wipers. Actually, however, it will be satisfactory to connect this lead to any portion of the frame of the machine. since it is preferably connected to the ground side of the oscillator and may thus be safely grounded on the frame of the lasting machine. After an interval of only a few seconds the cement will have been activated by the field and will, as soon as the field is cut off, return to its solid state to cause the adhesion of the upper to the insole. The machine will then proceed with the completion of its cycle, withdrawing the wipers and depressing the toe rest 42 etc., permitting the removal of the shoe from the machine.

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

1. In a machine for lasting shoes which have been assembled on lasts having metal toe plates, supporting means for the toe portion of an inverted shoe, lasting means engaging the overlasted upper on the bottom of the shoe, means for connecting one of said means to one side of a high-frequency circuit, and means for connecting the other side of said circuit to-a toe plate on the last of said shoe, thereby to set up an electrostatic field localized at the toe end of the shoe.

2. In a machine for cement lasting a shoe upper to an insole on a last, means for activating thermoplastic lasting cement comprising a lasting device for engaging the overlasted margin of the upper of a shoe, means connecting said device to one side of a high-frequency circuit, and means for connecting the other side of said circuit to a toe plate carried on the last within the shoe.

3. In a machine for cement lasting shoes with apertured insoles which have been assembled on lasts having metal toe plates and which have been provided with an adhesive between said insole and the overlasted upper, a lasting device for conforming the upper to the last and drawing it over the margin of the insole, means for connecting one side ofa source of high-frequency current to said lasting device, and means for connecting the other side of said source to the toe plate.

4. In a machine for cement lasting shoes which havebeen provided with an adhesive between an insole embodied in said shoe and the overlasted margin of the upper thereof, a lasting device which in one position of operation engages the overlasted margin of the upper, means for connecting said lasting device to one side of a high-frequency circuit, an electrode associated with another portion of the shoe constructed and tured insoles and which have been assembled on shoe lasts having apertured metal toe plates,

positioning and gripping means comprising a tact with the plate, lasting mechanism comprising a wiper movable to wipe the upper over a margin to press it into position there-' of the insole and upon, said shoe having a film of cement between the insole and the overlasted upper, and means for connecting a source of high-frequency current to said locating pin and said wiper thereby to produce an electrostatic field between the wiper and the plate and passing through the cement to activate the latter to stick the upper in lasted relation.

6. In a machine forcement lasting shoes which have been assembled'on lasts having metal toe plates and which have been provided with an adhesive between an apertured insole embodied in said shoe and the overlasted upper thereof, shoe-supporting means, lasting mechanismcomprising upper-tensioning means and upper-wiping means adapted to press the overlasted upper into firm engagement with the insole, means operating through the aperture in said insole to connect a toe-plate with one side of a highfrequency circuit, and means for connecting the other side of said circuit to one portion of said lasting mechanism.

WALTER S. ROGERS.

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