US2834987A - Dipping last - Google Patents

Description

May 20, 1958 M. c. TEAGUE DIPPING LAST 2 Sheets-Sheet 1 Filed Sept. 21. 1953 ATTORNEY I May 20, 1958 M. C. TEAGUE DIPPING LAST Filed Sept. 21 1953 2 Sheets-Sheet 2 INVENTOR. Wf/FWW/V 6'. 75/4605 ATTORNEY United States PatentO 3 Claims. (Cl. 18.-41)

This invention relates to a dipping last for casting footwear having pre-set folding uppers to provide a normally closed expandable foot opening which will facilitate insertion of the foot in the footwear.

Heretofore various articles such as footwear have been cast on a clipping last by a dipping process. These articles can be made of various materials which are suitable for use in a dipping process, the material most widely used in dipping processes heretofore has been rubber. In making articles of rubber by a dipping process, a dipping last having the configuration desired in the finished article is provided. This last is immersed in a bath of aqueous or solvent dispersed natural or synthetic rubber which may be unvulcanized or pre-vulcanized. The last, containing a layer of rubber thereon, is then removed from the bath, this rubber is solidified such as by means of a coagulant, and the process is repeated until the coating of rubber on the last has attained the thickness desired in the finished article. Thereafter the rubber may be vulcanized if necessary, and then the article is stripped from the last, trimmed, lined, etc. to produce the finished footwear desired.

The present invention contemplates a last for casting footwear by a dipping process in which the footwear is to be made of rubber or of any other suitable material which will lend itself to use in a dipping process. More particularly, this invention contemplates a dipping last to be used for casting articles of footwear such as boots which have walls forming an expandable leg opening for insertion of the foot in which the walls are pre-set to a curved configuration, so they will tend to maintain this opening closed. Because of the configuration of the foot and lower leg, it is desirable that footwear such as boots have an expandable leg opening to permit passage of the foot when the footwear is donned or doffed. This leg opening should be expandable to permit insertion or removal of the foot in the footwear, but it should be so constructed that when the foot is inserted in the footwear it can be closed snugly about the wearer's foot and leg to hold the footwear in place during normal usage and to present an attractive appearance on the foot of the wearer.

It is an object of this invention to provide a dipping last for casting footwear on which can be produced footwear having an expandable leg opening whose walls are preset to a curved configuration lying closely adjacent the leg embracing part of the upper, so the opening tends to x close and to remain closed in its normal position. Yet the expandable pocket cast on the last of this invention can be readily expanded when desired for insertion of the foot. Consequently the footwear produced on the dipping last of this invention will tend to assume a closed position after it is donned so that it may be secured in this closed position with little effort to arrange it to provide a snug fit and an attractive appearance.

in accordance with this invention a dipping last is provided having the exterior surface of its body shaped to conform to the shape desired in the finished footwear.

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The shank of this last has a circumferential dimension less than that required for the foot opening in the foot wear leg to be cast thereon, i. e. it has a circumferential dimension sufficient, for example, to provide a boot cast thereon with a leg opening that is large enough to embrace the leg of its wearer neatly without stretching the boot upper, but which opening therefore is not large enough to permit insertion of the foot therethrough conveniently without stretching the boot upper because of the configuration of the foot and ankle. A fin or wing is' provided which is fixed to the last and extends both longitudinally and laterally of the shank, so the shank and fin have a combined linear surface dimension measured circumferentially of the axis of the shank that is sufiicient to provide an expandable foot opening in the boot leg cast thereon to permit the entrance of the foot into the boot without stretching the boot upper.

In one specific embodiment of this invention a pair of thin fins are fixed to the shank of the last at opposite sides thereof and project forwardly of the shank and extend laterally thereof to curve partially about the shank in close proximity to the external surface of the shank of the last. This specific kind of last will produce a boot of the blucher type in which two pairs of walls united at their forward edge project forwardly of the leg of the footwear on either side of its center, and in which a gusset or tongue-like member is fixed between the two innermost walls to form in conjunction with these several walls an expandable pocket. Since the fins curve forwardly and laterally of the footwear leg and in close proximity to its outer surface, these walls will be preset in a closed position, so that although the pocket may be opened without stretching the walls of the boot to permit insertion of the foot, when the pocket is unre strained its walls will tend to fall into the closed position.

By providing a thin wing which extends longitudinally and transversely of the shank, footwear can be cast on the last which will have walls forming an expandable pocket that will tend to assume a position adjacent the body of the footwear cast thereon. Furthermore, by providing fins or wings on the last which are disposed in close .promrnity to the surface of the body of the last, an area can be provided at the base of these fins where ,they join the body of the last in which a film of the material cast thereon will tend to bridge across the small distance between the wing and the body of the last.

This bridging material will constrain the folds of the tion and of its advantages, reference should be had to the following description of specific embodiment of it when read in conjunction with the accompanying drawings wherein:

Fig. 1 is a perspective view of one form of dipping .last embodying this invention;

Fig. 2 is a sectional view through the shank of the last substantially on the line 22 of Fig. 1;

Fig. 3 is a perspective view of a second last embodying this invention;

Fig. 4 is a sectional view through the shank of the last substantially on the line 4-4 of Fig. 3;

Fig. 5 is a view substantially on the line 55 of Fig. 1; and

Fig. 6 is a cross sectional view of the boot cast on that portion of the last shown in Fig. 5.

Referring now to the drawing, there is shown in Fig. 1 a dipping last to be used in casting boots of the blucher type having an expendable pocket in the leg'of the boot to'p'ermit insertion of the foot in the boot which pocket had folding walls that are pre-set to a closed position for the expandable pocket. The dipping last comprises a last body having the usual foot shaped portion 11 and shank 12 Whereon are to be cast the foot and leg respectively of the footwear. As is customary in dipping lasts, suitable means (not shown) may be provided projecting from the upper surface of the shank 12 of the last to mount the dipping last on a clipping apparatus.

In the embodiment of this invention shown in Figs. 1 and 2, the dipping last 10 is provided with a pair of thin wings 13, 14, which are fixed to the shank 12 of the last at their bases 15, 16. These wings 13 and 14 have a substantially triangular shape as seen in side profile with their forward edges 17, 18, extending vertically of the footwear and their upper edges 19, 20, extending horizontally of the footwear. However, it will be appreciated that other shapes may be given these wings as desired to produce a boot cast thereon having the desired appearance. As best shown in Fig. 2, the wings 13, 14, are fixed at their bases 15, 16, to the side of the shank of the last and project longitudinally forward of the shank and laterally toward the center of the last to curve about the shank. These fins 13, 14, excepting at their bases 15, 16, are spaced a little distance from the opposed external surface 21 of the shank of the last, so that they have surfaces 22, 23 which extend circumferentially of the shank 12 of the last that are spaced a little distance from the surface 21 of the shank 12. The distance by which surfaces 22, 23 of the fins 13, 14 may be spaced from the surface 21 of the shank may be varied somewhat, but the surfaces 22, 23 must be spaced at least the minimum distance from the surface 21 of the shank of the last which will permit the casting of discrete films on the surface 21 and on the surfaces 22, 23 respectively. Although this distance will vary for different materials which are to be used to cast a boot on the last, and although the spacing may be made greater than this minimum distance for any given dipping material if desired, it has been found that a last wherein the surfaces 22, 23 are spaced from the surface 21 approximately 4 of an inch throughout substantially their entirety will produce satisfactory footwear having pre-set folding uppers when the footwear is to be produced of a rubber latex.

It will be apparent that when the last 10 is immersed in a dipping bath, a coating of material from this bath will be deposited on the external surface of the foot portion 11 and shank 12 of the last, and more particularly a unitary seamless coating of material from the dipping bath will be deposited on the surface of the shank 12 including the surface 21, and on the surfaces 22, 17 and 24 and the surfaces 23, 18 and of the thin fins or wings 13, 14 respectively. There will thus be produced a boot which has in its legs a wall conforming to the rear portion of the shank 12 and which has an expandable pocket that is formed by walls of material deposited on the surfaces 14, 23 and the surfaces 24, 22 of the fins 14, 13 respectively which walls are joined at their for ward edges by the material deposited on the surfaces 18, 17. Between these walls a gusset or tongue-like member will be formed of the material which is deposited on the surface 21 of the shank 12, and the material deposited on the several walls of the fins 13, 14 together with that deposited on the surface 21 will form an expandable foot opening in the leg of the footwear which may be expanded without stretching the leg of the footwear to permit insertion of the foot therein. The walls of this pocket will be pre-set to the position in which they are cast on the dipping last, and specifically they will be pre-set to a position in which they extend forwardly of the shank and laterally toward the center of the last to thereby maintain the expandable opening in the leg of the footwear closed.

Referring next to Figs. 3 and 4 there is shown another embodiment of a clipping last in accordance with this invention adapted to produce footwear having pre-set folding uppers.

In the embodiment shown in these figures,'a dipping last 10' is provided having a foot portion 11' and a shank portion 12. At the forward portion of the shank 12 a pair of thin fins 13', 14' are fixed to the shank 12' of the last. The particular fins shown in the drawing have a generally triangular shape as seen in side profile in which their upper surfaces are substantially horizontal, and their forward surfaces conform to the forward outline of the footwear. As best shown in Fig. 4, these fins 13', 14' project from a base 15 where they are fixed to the shank of the footwear laterally outwardly of the shank of the footwear and rearwardly of this shank in close proximity to the surface 21' of the shank of the footwear. It will be apparent that when the last shown in Figs. 3 and 4 is immersed in a dipping bath, material from the bath will be deposited on the foot 11' and shank 12' of the last, and that a thin film of material from the bath will also be deposited on the surfaces of the thin curved fins 13, 14', so there will be produced a footwear having a leg portion conforming substantially to the outline 12' of the shank but having walls formed by the deposit of material from the bath on the fins 13, 14' which walls will provide an expandable foot receiving opening in the leg of the footwear cast on the last. These walls of the expandable leg opening will be preset to lie adjacent the body of the leg of the boot cast on the last when the expandable leg opening is not held open.

Referring next to Fig. 5, there is shown greatly enlarged a further detail of the last in accordance with this invention which will produce footwear having an expandable leg opening therein in which the footwear will tend to remain closed. In this Fig. 5, there is shown a partial sectional view of the last adjacent the base of the thin fin 13 showing the last when material from the dipping bath is deposited thereon. At this point, the inner surface 22 of the fin 13 is disposed closely adjacent the surface 21 of the shank of the last. The distance between the surfaces 21 and 22 in this area is so little that the material 26 deposited on the last will bridge over between the surfaces 21, 22, as shown at 27, to lock these surfaces together for a littie distance from the line of juncture 28 of the base 15 of the fin 13 and the shank 12. This bridging material will assist in maintaining the material deposited on the surfaces 21, 22 folded so they have a sharp crease along the edge 28, as best shown in Fig. 6. This maintaining of this crease will tend to maintain the material deposited on the surfaces 21, 22, and on the surfaces 21, 23, in the position which they occupied on the dipping last.

Referring next to Fig. 6, it will be seen that if the pocket in the footwear cast on the last of this invention is forced open, that part of the material 26 adjacent the outer surface 29 of the boot will be stretched considerably before that part of the material 26 adjacent the inner surface 30 of the boot will be stretched at all. This is due to the fact that the bridging material in the area 27 has resulted in a surface dimension measured circumferentially of the footwear along the outer surface 29 between the point a and b that is much less than the distance between corresponding points a and b on the inner surface 30 of the footwear. Consequently if the expandable pocket is to be opened fully, the material forming the footwear must be stretched adjacent its outer surface in this area, and when the stretching force is released the footwear material will contract until the pocket assumes its closed position in this area.

It will be appreciated that a similar phenomenon will occur near the base of the wing 13, 14' of the embodiment of the invention shown in Fig. 4.

Although dipping lasts for casting footwear which are essentially of the blucher type has been shown and described, it will be appreciated that other types of footwear may be made embodying the instant invention. Thus for example if a single folding flap is desired in the footwear to be cast on the last, that wing of the last shown in Figs. 1 and 2, and in Figs. 3 and 4 which is to be disposed on the outside of the footwear might be omitted, so that a pre-set folding expandable foot opening may be cast on the last which has a single pair of walls that can be folded over toward the outside of the footwear. Other and further embodiments of this invention will be apparent to those skilled in the art.

Having -.thus described my invention, what I claim and desire to protect by Letters Patent is:

l. A dipping last for casting boots with pre-set folding uppers, said last having a circumferential dimension less than that normally required for the foot opening in the bootleg to be cast thereon, comprising a shank, said shank having a pair of fins extending therefrom, said fins being fixed to said last at their bases, the remainder of said fins being spaced a little distance from the surface of said shank and extending therearound, said fins extending from the portion of the last on which the upper rim of the boot forming the foot entrance opening in the boot leg is to be cast and downwardly therefrom a substantial distance, the shank of the last and said fins having a combined linear surface dimension measured circumferentially of said shank greater than said shank.

2. A dipping last in accordance with claim 1 in which the bases of said fins are fixed to said last along a common line.

3. A last in accordance with claim 1 in which the bases of said fins are fixed to said last at opposite sides of said shank.

References Cited in the file of this patent UNITED STATES PATENTS Eade July 10, 1956

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