US 1647639 A
Description (OCR text may contain errors)
Nov. 1,1927. 1,647,639-
M. LARSON CAST OR TEMPORARY SHOE LAST AND METHOD O1" MAKING SAME Filed Feb 19. 1926 2 smug-sheet 1 Nbv. 1, 1927; Q 1,647,639
M. LARSON CAST on TEMPORARY SHOE LAST AND umnon or 'nummesum Filed Feb. 19. 1926 z Sheets-Sheet 2 for the manufacture-of footwear thereover.
Patented Nov. 1, 1927.
- voeuvre!) srA'rEs PATENT OFFICE.
MARTIN LARSON, or LA'GRANGE', rumors.
CAST, OR TEMPORARY SHOE LAST AND METHOD 6F MAKING SAME.
Application filed February 19, 1926. Serial No. 89,346.
The invention relates to an improved form of cast ortemporary shoe last and to an improved method of making the same from which a last of wood or other material of a'morefirm and enduring .character'may be made if desired for use particularly in the manufacture of custom made footwear fashioned in the form of boots or shoes from leather or other suitable materials.
adapted to custom made shoes for feet that are deformed or reason it is required that exceptionally accurate fits of such shoes or other footwear is required, although the use of the invention is not necessarilyso restricted, because it may be used equally 'well' in all cases where custom made footwear of accurate fit is desired.
It is the primary object of my invention to'provide an improved method of making a cast or temporary shoe last preferably of a flexible material so constructed andv reinforced that it ma be reproduced in a facsimile from. woo or other material of a more firm and enduring character to be used It is a further object of this invention to provide an improved method of casting a temporary shoe last that shall be capable ofv producing an accurate last or cast of the foot of the subject with a minimum amount of inconvenience to the subject.
Other objects of the invention will appear from the following description of my improved method of producinga castor temporary shoe last taken in connection with the accompanying drawings forming a part of the specification, the novel features being set forth 'in the appended claims.
In the said drawings, Fig. 1 is a perspec:
tive view of an impression in position on the foot of a subject before removal, the outline of a portion ofthe foot of the subject being indicated in dotted lines andthe line of severance of the wall of the impression being 'shown also in dotted lines.
Fig. 2 isa view similar to Fig. 1 of the hollow impression ormold of Fig. 1 after a portion 'of the wall of the mold or impression is severed, as clearly indicated in the figure, and the impression or .mold also shows the insertion of metal reinforcing members adapted to appear later in the temporary last when cast.
My invention has been found particularly diseased or where for anyting Fig, 3 shows the mold or impression with the remforcments in it of Fi 2 having the casting material as plaster 0 Paris poured thereinto after the impression or mold has been closed along the line of severance by taping or wrapping, as indicated in this figure. v
Fig. 4 is a view of the casting of Fig. 3
after the impression or mold has been untaped and removed from the casting of frangible material, the view showing the reinforcing members in the casting and also showmg a temporary frame or mold, as preferably used in carrying out .the process of building out the toe ortion of the temporary last'by the addition of plastic material thereto in the outline of the temporary mold so that when the temporary mold is removed the completed last will a pear as in Fig. 6 with the built out or built on to portion in the desired relation for serving as a complete'last or outline for the shoe or 'other footwear to be made thereon.
Fig. 7' is a sectional view taken on line -7-7 ofFig. 5 looking in the direction of the arrows and showing the manner in which the temporary mold is applied to the cast for the toe building operation.
Heretofore casts for making lasts and footwear have sometimes been produced by putting the foot of the subject into a molten material adapted to harden quickly on settened with water, which is known to have the quality of setting within a relatively short time after being mixed to the form of a mortar or pasty mass and when molds have thus been taken the foot of the subject .is placed in the molten soft material and such as plaster of Paris when mois- Insu'ch methods of castin it has been common after the molten 1 m terial sets around the foot or member of which a cast is being taken to cut the so that it will be separated in two parts,
a thread or other sometimes by means of v The tendency to suitable cutting means.
' and to overcome the defects of such methods of making casts and producing lasts particularlyfor the manufacture of footwear, I have provided my improved method and reinforced temporary last as herein described. and claimed, which is preferably produced and practiced by producing a temporary form of mold or casing for making the cast in the manner and construction illustrated in Fig. 1. This is accomplished preferably by taking elongated strips of rather loosely woven cloth such as cheese cloth and first saturating the same in a mortar, or pasty mass made by mixing water and plaster of Paris together and wrapping said strips around the footof the subject in a plurality of layers in the manner illustrated in Fi 1. The number of thicknesses of the 0 0th strips that shall be used in making up the casing is not vital just sothat enou h layers are utilized to give the casing or orm sufficient firmness'when the plaster of Paris with which the strips are saturated shall set so that the mold will have the desired firmness to support and control the form of the cast. In practice I find that I can utilize anywhere from two or three thicknesses of saturated cloth in making up the form or mold up to five or six thicknesses and since on account of the extreme irregularities of the human foot there may be some difficulties especially on the part of a novice in attempting to make a wrapping or mold that shall be uniform throughout as to the thicknesses of cloth employed in difierent parts of the mold, it may be stated that it is not im ortant if the thicknesses of cloth in the mo d wall shall vary at different locations therein, since it will be found that when the plaster of Paris absorbs the water in the mortar and sets, the mold'or hollow form will be found to be sufiiciently firm throughout the walls thereof when-removed from the foot of the subject and allowed to drfy, to support and give perfect reproductive orm to the casting to be made from the mold thus formed.
In Fig. 1 of the drawings where the mold is shown in section around the top wall thereof it will be seen that approximately 1 four thicknesses of cloth are indicated-as by reference character 11, the mold generally being designated by reference character 10. The cloth strips used in the wrapping to form the mold or casing are shown in the drawings and are indicated by reference character 12. As soon as the stri sof cheese cloth saturated in plaster of aris mortar are in the form shown in Fig. 1, condition to designated dry, and this result may be accomplished by causing the subject to remain first taken to see the mold or form is of course. in.
memes quiet for a brief interval of time to allow the plaster of Paris to set, precautions being that the walls of the mold,
which when first Wrapped will be flexible,
are pressed into close contact with every part .of the foot. I find in practice that comparatively little difliculty will be found in thisrespect on the top parts of the mold Where it contacts withthat part of the foot over the top from the toes back to the ankle, but I have experienced in practice some dif-v ficulty in being ableto insure that the flexible saturated walls portions of the mold on the bottom of the subjects foot. shall adhere closely to the irregularities of the foot'bottom and since the weightof a person must be borne by the-contact of-the bottom portions of the foot with the wall of-the footwear,- one of the most important and essential things'in producing a perfect piece of foot' wear is to insure a perfect fit of the foot with the bottom parts of the shoe. In order therefore to insure close cont-act of the mold when in its flexible condition with the bottom of the foot to get a perfect impression thereof, I have experimented with various means to obtain this desirable contact while the flexible walls of the mold are setting and I have found that the most advantageous thing to use to secure. a, perfectime pression of the bottom of the foot' is to have the subject press the foot with the wrapped mold thereon upon some cushioning material such as sponge rubber which/will permit any protruding parts of the foot to project suitable cutting means an incision willbe made in the top of the form or casing corresponding somewhat to the usualslit or opening in an ordinary pair of shoes where they are laced together, this iline of severance beingdesignated by the broken line 13 of Fig. 1 and'the line of cleavagein Fig. 2 designated by the same reference character."
When the form or mold 10 has been cut as designated and removed from the foot of the wearer it-will be obvious. that if the plaster of Paris has had an opportunity to absorb the water of crystallization and to set that the walls of the form or mold thus cast or impressed will be comparatively firm. Since the purpose of the form or mold 10 is to make the ultimate temporary last casting it is only neeessaryto. allow the'saturated' cloth material to set before beginning the operation of casting the temporary last, and this may therefore be undertaken usually at Car . permanent any time even a few minutes after the first impression or form is taken, or the form or mold may be allowed to set and dry for any length of time, as a few days or months, or even years. Before making the cast in the form 10 I prefer to introduce special strengthening means for strengthening the ultimate casting and supporting the same when the temporary casting is used in an automatic machine for the production of a last made of some material more permanent and durable than plaster of Paris, as for example, wood, which is the material commonly used in making shoe lasts. Into the form or mold 10 I therefore preferably insert metallic reinforcing members formed of a heavy grade of steel wire of suflicient diameter to give the necessary strengthening qualities, said reinforcing members being preferably in the form illustrated in Figs. 2 to 7 inclusive, and from which it will be seen that they are. given the general shape of the capital letter L having the elongated body portions 15 of a length which may approximate the entire length of the last so as to extend longitudinally on the interior thereof usually near the bottom and they will therefore have the comparatively short- -angular portions 16 and bent beyond the short portions as at 17 into parallel relation with the main body portions 15 so that they may be inserted into the hollow forms or molds by puncturing the walls thereof at the heel and toe as shown most clearly in Fig. 2 so that the major portion of the part 15 will lie within the form or mold with a short U-shaped extension on the outside at the heel, the part 17 usually extending only a short distance through the wall of the form or mold.
In an application for Patent Serial No. 89,258 filed of even date herewith, I have shown, described and claimed a machine which is adapted for utilizing fragile, temporary casts in making lasts of a permanent material, and it is feature of the present invention to so strengthen the temporary last which is a product of the method herein claimed so that said temporary last or flexible material may be successfully used as a pattern. To that end the strengthening or reinforcing member 15 will be inserted at the heel end of the form or mold as shown in Fig. 2 so that the portion 16 will extend vertically While the corresponding part will extend horizontally as illustrated .in Fig. 2 at the toe, this arrangement of the reinforcing members being devised for the purpose of enabling the temporary last to be more readily and easily grasped and clamped in the machine. When the reinforcing members are therefore in the form as illustrated in Fig. 2 the slit'portion 13'will be closed and wrapped by suitable taping or other closure means as designated by reference character 18 in Fig. 3. The form or mold is then in position to receive plastic material for the formation or casting of the temporary last and material of this character is designated by reference character 20 in Fig. 3'.
In Fig. 4 the plaster of Paris casting 20 of Fig. 3 is shown removed from the mold "or form 10 and having the reinforcing membars 15, 16 and 17 imbedded therein. An inspection of the view of this figure Wlll show that the casting thus formed is a facsimile of the foot of the subject and although a most accurate form of footwear may be desired by the subject, nevertheless, it is not customary to make up footwear especially with respect to the toe portions that follows the absolute contour of the foot. more, in the'remov'al of a last from a shoe being manufactured and in the insertion of the same into a shoe for any purpose during manufacture, and in manipulatingthe top portions of footwear in maunafcture, it is quite customary and desirable to trlm the last around the top above the heel portion which maybe advantageously done somewhat in the manner in whichthe casting 20 comprising the temporary last is shown trimmed in this regard in Fig. 5 so that the last will now appear in the finished form as shown in Figs. 5 and 6 where the top or part which corresponds to a section through the ankle of the subject, as .designated at 20*, is of an elongated oval form rather than the almost circular section ap pearing on the horizontal temporary casting of Fig. 4. It is also usually desirable to perform some special operations on casts taken in this manner at the toe portl'ons Furtherthereof and a temporary mold as designated building out the toe portions of the temporary last by the addition of plastic material such as plaster of Paris and will be sha ed and allowed to harden after the remova of the temporary mold 25 in the manner illustrated in Figs. 5 andfi so that when the toe of the last is completed the reinforcing portions 15, 16 and 17 of the metallic reinforcing device will be substantially covered at the toe and be imbedded in the material so that they will be in position to serve their strengthening function when the toe of the temporar last is grasped by the pattern 'holding evice of a machine in the manner ment and form shown in Fig. 6 varying in described in my aforesaid co-pending ap li- .to the rear of the heel so that it may be en- 'gaged by the gripping device of the last making machine.
When my improved temporary last 1s completed, it will be in the substantial arrangeshape of course, according to the shape of the foot of the subject and when completed, as shown in Fig.v 6, it may be put into the lastmaking machine or reproduced in facsimile by any desired method in Wood or any other desired permanent last material.
A last formedin the manner and by the method described will insure, especially for custom work and in making shoes under difficult conditions, the most perfect fit in footwear that is known in the art and without the employment of any objectionable or nerve racking methods that have been heretofore employed in makin casts. v
l/Vhile in the above speci cation I have described one embodiment which my invention may assume in practice, it will of course be understood that the same is capable of modification and that modification may be made without departing from the spirit and-scope of the invent-ion as expressed in the following claims. s
I claim 1.j The'her ein described method of forming arcast last of frangible material for use in the manufacture of custom made footwear which consists in producing a mold or casing of strips of flexible material saturated in wet plaster of Paris or analogous material 7 wrapped closely around the foot of the subject and allowed to harden thereon until the walls of said mold or casing take a permanent set, slitting a part of the wall of the rudder casing thus formed and removing it from the foot of the subject, closing-theslitted portion and inserting reinforcing means from the exterior through the wall of the mold or casing to be ,imbedded in the casting to be formed therein, casting a last of frangible material :in the said mold or casing, and finally removing the casting with the reinforcing material-"therein from the mold or casing. v A
2. The herein described method of forming a cast last offrangible material for use in the manufacture of custom 'made footwear which consists in producing a mold-0r casing of strips of flexibleni'a'terial saturated in memes 'last casting by adding plastic rapidly drying material to vthe toe portions thereof.
.3. The herein described method of forming a cast last of frangible material for use in the manufacture of custom made footwear which consists in producing a mold or casing of strips of flexible material saturated in wet plaster of Paris or analogous material wrapped'closely around the foot of the subject and allowed to harden thereon until the walls of said mold or casing take a permanent set, removing said mold or casing from the foot of the subject, casting a last of frangible material in the said mold or casing, removing the cast from the mold or casing, finally com leting the desired contour of the last by ad ing plastic rapidly drying material to the toe portions thereof,-and trimming and shaping the top or ankle portion thereof to render operation and insertion of the last more easy.
4. As an article of manufacture, a temporary last of frangible material having remforcing metallic members imbedded in the toe and heel portions, said reinforcing metallic members extending beyond the toe and heel portions thereof.
5 As an article of manufacture, a temporary last of cast frangible material having reinforcing metallic members imbedded in the toe portion, said reinforcing member havin the sald toe portion thereof.
a looped portion extending beyond 6. As an article of manufacture, a temporary last of cast frangible material, as plas- .ter of Paris, having reinforcing metallic members in the form of metallic rods or wires imbedded in the material thereof and extending substantially from the toe to the heel portion of the last, one of said reinforcing metallic members being provided withe'a projectin beyond the extremity of the loop hee portion 0 the last and the other of said.
metallic members having a loop at the toe portion of said last and adj acent the extremlty of said toe portion thereof.
gln testimony-whereof I have signed my name to this specification, on this 16th day of February A": D. 1926.
' MARTIN LARSON.