US2147707A - Bunion mold - Google Patents

Description

Feb. 21, 1939. P. o. KOEHLER 2,147,707

BUN I ON MOLD Filed March 25, 1936 2 Sheets-Sheet 1 INVENTOR. 8 Paul 0. Kaehler MN 3 W A TTORNEYS.

F. O. KOEHLER BUN I ON MOLD Feb. 21, 1939.

Filed March 25, 1936 2 Sheets-Sheet 2 Fig. 10

Fig. 16

INVENTOR.

F S mam h N 2 R 0 m Kw A 0 P Patented Feb. 21, 1939 PAT OFFICE 1 Claim.

It is desirable in making'fpads' to protect bunions, on the great toe'forexample, to have a replica made of the patients bunion and the nt part of the foot soas to facilitate "the 5 fashiflning of a bunion pad for the involved area;

To obtain a replica of this limited area it is not, of course, eithe'r'necessaryor desirable to take a cast of the entire-foot. Since no suitable molding flask has apparently been provided for making bunion replicas, they have usually been made heretofore by' manually fitting ormolding strips of gauze, covered with plaster over"and around the involved area, permitting theplast'er to harden or set so as to form a negative, and then,

15 aiter removing the negative'from the foot, filling it with plaster to form the desired positive or replica. This method is objectionab-le'becau'seit requires the use of a Skilled operator'to produce uniformly good results. It is also objectionable; 20 because it involvesbothrepeated contact'ofthe operators handswith the plaster; which' pro duces. deleterious drying efiects on the skin, and,

considerable dripping of plaster, which makes the operation unsightly. The present invention' is 25directed to means for and method of producing a bunion mold which avoids these objections;

Among the important objects of'the invention" are: to provide a simple form of flask which can be easilyand quickly manipulated by an unskilled and op'eratorto produce an accurate mold; to provide" a flask which minimizesto "a negligible degree either contact of the operators hands with plas-' ter or the dripping of plaster; and to *provide' a flask from Whi'c'ha; replicacanbe easily and 35 quickly removed without injury thereto.

With the production of the replicait hasbeen' the practice heretofore manually to shapaaround the bunion area, a soft protectivecore and to enclose such core between inside and outside covers of some suitable material such as'leather,

chamois, etc. Thepad thus formed has 'usually' been provided with means for securing it to the patients foot, such means generally taking the form of a fiat resilientbelt sewed to the pad and 45 arranged to encircle either thefoot'or the great toe. To obtain uniformly good results this method likewise requireda high "degree of skill. Fur thermore the pads once formed are not only apt to be difficult to clean but are very likely to 50 change shape when handled andwor'n." In fact the results produced by this method are,for"1 nost bunion conditions encountered, not much better; if any, than those obtained from suchpads' as are commonly sold on the market usually inthree 55 standard sizes.- The presentinventionis, therefore, also directed to a novel method of forming individual pads and to the novel 'form of the resulting pad.

Hence other important-objects of the invention are: to'prov'ide a novel method of mariufactur-- 5 ing a pad which can be'easily, quickly and inexpensively performed to produce an accurate fit and, at the' same time, to provide a means for securing the pad to the patients foot; to provide a pad of accurate and more or less permanent shape; to provide one which may be accurately duplicated in size and shape; and to provide one which canbe easily kept in a sanitary condition.

Theinvention is illustrated in the accompany- L ing drawings whereinzf- Figurel is a top plan view of a flask constructed in accordance with my invention;

Figure 2 is a side elevation thereof;

Figure 3 is a section taken through line 3-3 of Figure 2;

Figure 4 shows the position of the flaskrelatively to a patients foot during the negative or mold forming operation;

Figure 5 is a top plan view of the negative and 1 Figurefi is a perspective of the positive or replica formed from the negative;

Figure? is a top plan view of the replica;

Figure 8 is a section through 'a felt core roughly preformed to desired shape;

Figure 9 shows the core after it has been placed on the replica and molded to it manually;

Figure 10 shows a fabric placed over the'replica and core to hold the latter uniformly and tightly against the replica;

Figures 11 and12 show the replica of Figure 10 after it has been coated with rubber;

Figure 13 is a perspective of the completed pad after it has been removed from the replica and trimmed;

Figure 14 is an enlarged section taken through line I l-14 of Figure 13;

Figure 15 is an enlarged similar section taken through a modified form of pad; 45

Figure 16 is an enlarged similar section taken through another modified form of pad; and

Figure '17 is an'enlarged section of the pad of Figure 16 provided with an additional inner faced layerof suitable absorbent material.

Incarrying out the invention I provide a flask I which may be of any suitable shape but preferablyis of the semi-ovoid shape shown wherein the opening or mouth of the flask is ovate, i. e. made wider at'its rear or arch end than it is at its front or toe end. The flask may be composed of any suitable material but is preferably composed of a flexible material such as rubber. The bottom and ends of the flask are thickened and the bottom also made level to provide a suitable base 2 while its interior is provided with spaced longitudinal ridges 3, the bottom ridge preferably having at the center of the flask an amplitude smaller than that of the corresponding section of the other ridges. These ridges may be transversely arranged, if desired, but, however arranged, serve to provide mechanically weak sections or depressions in the negative along which it may be easily broken. The mouth or marginal edge 4 of the flask may, if desired, be turned horizontally inward to facilitate the retention of plaster.

In operation the flask is filled with plaster up to a suitable level, this level being delimited, in the embodiment shown, by the last ridge on either side of the flask. In taking an impression of a bunion, located say on the long arch side of the foot at the ball of the great toe, the patients toe preferably is held by the operator so that its bottom plane lies approximately in the bottom plane of the foot. The foot may be turned inwardly somewhat and the flask slightly tilted as it is manually brought into contact 1th the foot in a manner such as to bring the ;toe end of the flask over the great toe, the arch end of the flask against the long arch of the foot and the bunion area approximately into the center of the flask. With the flask thus positioned the operator may find it necessary to pinch or squeeze the sides of the flask somewhat in order to bring the marginal edge 4 into continuous contact with the foot and thus prevent or at least minimize the possibility of plaster dripping out of the flask. With the flask held in its proper position, wherein the bunion and toe are partially submerged in the plaster, the latter is allowed to set and thus form the negative 5. The replica may now be conveniently made simply by coating the surface of the negative with a separating material and then filling it with plaster. When the plaster, forming the replica 6 has hardened or set it will be partially encircled by the negative thus necessitating the breakage of the latter to effect its 7 removal. The negative may be broken in any suitable manner as by striking it with a mallet. By having the negative formed with mechanically weak sections or lines, it will be easier to break than would otherwise be the case; hence the danger of damaging the replica during the removal operation is minimized. Upon removal of the replica, it should be trimmed to remove rough spots and otherwise processed for such purposes as may be desired. In order more conveniently to carry out the other objects of this invention I prefer to provide the replica with a beveled edge 7 at its bottom and to trim the great toe portion of the replica to a dimension fractionally smaller than that of the patients great toe.

It will be appreciated that this form of flask can be easily handled and manipulated by the operator; that, with it, the mold forming operation can beeasily and quickly performed by comparatively unskilled operators to produce an accurate mold; and that its form and flexibility render possible the performance of the mold forming operation without occasioning contact of the hands with plaster or dripping of the plaster. With an accurate mold formed, it is, of

. ible cover.

course, an easy matter to produce an accurate replica and, by virtue of the mechanically weak negative provided, it is also easy to remove the replica safely.

The replica illustrated has an enlarged portion or bunion area 8 around which a bunion pad may be fashioned in the normal way. However, in further accordance with my invention, the pad is formed by manually shaping or molding a suitable core to and in accurate conformation with the shape of the bunion area and then permanently maintaining it in such shape by spraying, brushing, or otherwise applying a suitable material which will adhere to it and form a flex- While many materials are no doubt suited for this purpose I have found that rubber solutions which set or vulcanize at room temperatures in comparatively short periods of time to form adhering flexible rubber sheets, are satisfactory. Solutions of this character are well known and readily obtainable on the market; hence detailed description thereof is not deemed necessary.

The particular type of pad to be manufactured will of course depend upon the particular bunion condition involved. If a bursa or soft bunion condition is involved then ordinarily a soft type of pad will be prescribed. Such pad may be made by wetting a core 9, which is composed of felt or other suitable material and which preferably has already been roughly preformed to the approximate shape desired as shown in Figure 8, placing such core over the bunion area as shown in Figure 9, and then manually pressing and molding it around the bunion area 8 until it conforms accurately to the shape thereof. It may be desirable or necessary to hold the core in its precise manually molded form during the application of the setting material. In such event, a thin sheet of gauze I is preferably stretched tightly over the wetted core, as in Figure 10, and its ends turned underneath the replica and there fastened or held together by adhesive tape or other suitable means. With the core thus firmly held in position, a coating H of setting material may then be applied over both the core and gauze as shown in Figures 11 and 12. Where a rubber solution is used as a setting material more than one coating will normally be necessary and preferably four to six. With the application of each coat a suflicient time, usually about 15 minutes, should be permitted to elapse for setting or vulcanizing purposes before the next coat is applied.

In order to attach the pad to the patients foot, the customary form of belt may be sewed or otherwise secured to the pad. In place of a belt of this character I prefer to extend the application of the outer cover coatings I I to and around the great toe of the replica and thus at the same time form a snugly fitting securing belt I 2. When the desired number of coatings of the core and toe have been applied and permitted sufficient time properly to set the entire pad may be stripped from the replica and then made ready for use as by trimming away excess material to the form shown in Figure 13 for example. It will be understood of course that the rubber coatings form over the core a single unitary sheet or cover H which firmly adheres to the core and flexibly holds it in the shape to which it has been molded. A pad of this character obviously can be easily and quickly secured to or removed from the foot, when secured, will be comfortable to the wearer, and, when re moved, can be easily cleaned and therefore easily maintained in a sanitary condition.

Where a bunion condition of a small bony nature not having any appreciable callous or corn is involved the use of a hard pad may be in order. A pad of this nature may be easily and quickly made by taking a core 9, preferably of felt, and dipping it into the rubber or other setting material. Before the setting material has time to set the core is molded by hand to the bunion area and maintained manually or otherwise in its molded position for a time suflicient to permit the material to set. While gauze or other suitable means may likewise be provided for holding the core accurately in its molded position such means will with a rubber dipped pad usually be unnecessary inasmuch as the rubber, in setting, not only holds the core in molded shape but also adheres firmly but not permanently to the replica. The core and replica may now as before be coated with rubber to form a cover Ila and band I211. The steps. of this method and the other methods hereinafter described are not deemed necessary to illustrate inasmuch as they are generally similar in character to the method illustrated in Figures 8 to 13 inclusive. However, the cross section of a portion of the pad formed bythe method just described is illustrated in Figure 15, and, by the methods hereinafter described, in Figures 16 and 17 respectively.

The majority of bunion conditions encountered are of the bony type but having an additional callous or corn. For this type of bunion a suitable pad may be easily and quickly prepared simply by providing the replica with say six coatings of rubber to form an inner cover l3 for the pad, molding a core 9 of felt, sponge rubber, or other material over the coated replica, securing the core to the cover l3 by some suitable means such as rubber cement, coating over the core and replica a sufilcient number of times to provide an outer cover I lb and belt I21) and then trimming to finish the product. Where, as in this method, the cover i3 is directly applied to the replica, it may be extended downwardly onto the beveled edge I of the replica in order to anchor it firmly.

In some instances a condition, such as acidosis, may be encountered which requires the use of an absorbent material between the pad and the bunion area. For conditions of this type an absorbent material l4, such as chamois, may be initially secured over the uncoated replica in much the same manner as the gauze sheet l0 heretofore mentioned was secured. With the chamois covering l4, held tightly in place the final product, a cross section of which is shown in Figure 17, can be formed by following the steps used in producing the product of Figure 16.

While I have described this invention in connection with the formation of separate bunion pads for each individual bunion condition it will of course be understood that the invention may be used in the manufacture of bunion pads of standard sizes which are intended for general application. Consequently the term bunion replica is not intended to mean a replica of any particular bunion area but should be construed in a sense broad enough to cover any form of model used either in the manufacture of individual bunion pads or standard pads.

Having described my invention, I claim:

A molding device for bunions and the like, comprising a flexible hand flask having an open casting space to receive the mold forming material and a flange directed laterally inward to form an ovate mouth for said space, and means associated with said flask to create a weak section in the mold.

PAUL O. KOEHLER.

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