US3494422A - Plastic horse shoe and method of applying to hoof - Google Patents

Description

Feb. 10, 1970 F M CLARK 3,494,422

PLASTIC HORSE SHOE AND METHOD OF APPLYING T0 HOOF Filed Jan. 16, 1967 2 Sheets-Sheet 1 INVENTOR.

FRANK M. CLARK ATTORNEYS Feb. 10, 1970 v F. M. CLARK 3,494,422

PLASTIC HORSE SHOE AND METHOD OF APPLYING TO ROOF Filed Jan. 16, 1967 2 Sheets-Sheet 2 United States Patent Office 3,494,422 Patented Feb. 10, 1970 US. Cl. 168-4 8 Claims ABSTRACT OF THE DISCLOSURE The application discloses a novel shoe for hoofed animals, formed of a synthetic resin material, such as an elastomeric polyurethane plastic, that may be cast to shape and size while being sufficiently flexible for close fitting to the hoof. The shoe exhibits resistance to wear and a'braison comparable to iron and other metallic shoes. It includes calks and cleats that may be trimmed, a protective flange for the front edge of the hoof, and a channel for lubricant beneficial to the hoof. A method and apparatus for applying the shoes without nails is also disclosed. The shape and effective size of the shoe can be adjusted by the shortening of a heel crossbar.

BRIEF SUMMARY OF THE INVENTION This application relates to so-called shoes for hoofed animals, particularly horses.

For many centuries the conventional material for shoeing horses, in particular, has been a form of iron or steel. The shoes are normally fitted to the hoof while hot, and a great amount of skill is required to achieve the proper fitting without injury to the hoof. There have been known a few instances where metal shoes have been fitted and adjusted While cold, but this is a difficult task, and few shoers have either the time or the skill to achieve the proper fit with a cold metal shoe.

In this art, there are a number of factors which must be taken into consideration in selecting a proper shoe and fitting it to the hoof. The type of service in which the animal will be used is a consideration in selecting the weight and style of shoe to be used, and the gait of the particular animal, and to some extent even its habits, must also be taken into consideration. For example, it is recognized that shoes for racing thoroughbred horses are desirably light and thin, their main purpose being to help the horse to grip the track. Harness horses may require a number of different types of shoes in order to adjust the animals stride or alter its gait, and jumping horses usually require a rather large calk on the hind shoes. The same horse may have to be shod differently when the type of work or use to which it is put changes.

Particularly where shoes are fitted and selected to help correct gait troubles, the proper shaping and fitting is most important. It is possible to correct gait problems such as forging, interfering, and speedy-cutting with proper shoeing, and it is also possible to enable a horse afflicted with founder to walk and run reasonably well with proper shoeing. The fact remains, however, that metal shoes must in all cases be fitted hot, they are nailed to the hoof, and the metal shoes will abrade and thus be formed during use with sharp edges which can increase the injuries resulting where gait troubles occur. Also, metal shoes will transmit any shock directly to the hoof, with practically no shock absorption, and the possibility of injury from loosened nails, or even improperly applied nails, is well-known.

Rubber shoes have been known for some time, one of their chief uses being on horses used in the past to pull delivery trucks, especially over hard surface streets where the metal shoes made objectionable noise at night or in the early morning. Generally speaking, however, the rubber shoes did not have either the desirable wear or pulling characteristics, but were considered a compromise to give the horse adequate footing for its task while minimizing noise. More recently, some shoes have been available made of synthetic resin material, such as nylon, however these shoes are essentially direct replicas of the iron shoes, and it appears from experience with them that the wear characteristics are unsatisfactory, and they do not incorporate the desirable and novel features disclosed herein.

The object of the present invention is to provide a novel shoe for hoofed animals, particularly horses, which is formed of a synthetic resin material, preferably an elastomeric polyurethane plastic, that may be cast to the desired shape while still being sufficiently flexible to facilitate close fitting of the shoe to the hoof, and at the same time providing such a shoe which will wear and last as well as iron and other metallic shoes, even under hard use as in racing; to provide a horseshoe which achieves some shock absorption and thereby relieves the horse from some of the impact on its hooves and legs during hard running, while still maintaining satisfactory wear such that the shoes do not need to be replaced after an objectionably short time of use; to provide such a horseshoe which may be trimmed, shaped, and closely fitted, and applied to the hoof with or without the use of nails, thereby eliminating the objectionable features of nails previously used; to provide such a horseshoe which incorporates a protective flange that minimizes the tendency of the hoof edge to cut when it overreaches or interfers during a particular gait; to provide such a horseshoe in which the hoof surface of the shoe can be closely fitted to the bearing surface of the hoof, and wherein the hoof surface of the shoe incorporates a channel for holding a quantity of lubricant or the like which is beneficial to the horny structure of the hoof; and to provide a novel method and apparatus for shoeing horses and like animals.

Other objects and advantages of the invention will be apparent from the following description, the accompanying drawings and the appended claims.

In the drawings FIG. 1 is an elevational view of the bottom or ground surface of a horseshoe provided by the invention;

FIG. 2 is an elevational view of the top or hoof surface of the shoe shown in FIG. 1;

FIG. 3 is an edge view of the shoe shown in FIG. 1, as seen from the rear, or bottom of FIG. 1;

FIG. 4 is an edge view of the front of the shoe, as seen from the top of FIGS. 1 and 2;

FIG. 5 is a partial sectional view taken along lines 55 in FIG. 2;

FIG. 6 is an enlarged partial sectional view taken along lines 66 in FIG. 1;

FIG. 7 is a bottom elevational view of a modified form of shoe, omitting the cleats and incorporating calks at the rear;

FIG. 8 is an enlarged parallel sectional view taken on lines 88 of FIG. 7;

FIG. 9 is a perspective view showing a tool provided by the invention used to apply one of the novel shoes to a hoof; and

FIG. 10 is a bottom view of the tool holding a shoe on the hoof, with the open position of the tool shown in dot-dash lines.

Referring to the drawings, which illustrate preferred embodiments of the invention, and particularly with reference to FIGS. l6, the shoe provide by the invention comprise the body 10 cast or molded of a synthetic, wear resistant, resilient resinous material. This material is selected to provide a resistance to abrasion, even under conditions of hard use such as on racing or jumping horses, while still being sufliciently resilient to provide shock absorption which is beneficial to the hooves, legs and leg joints of the animal.

Particularly under racing conditions, substantial shock is imparted to the legs and leg joints of a horse. Conventional metal shoes, usually formed of cast iron, provide no appreciable shock absorption, but rather due to their hard and rigid structure, they tend to transfer the shock directly to the hoof and leg each time the hoof engages the ground. Metal shoes are difficult to fit, must be heated to a relatively high temperature for this purpose, and even then are difiicult to shape. An important feature of this invention is the discovery that certain materials are particularly suitable for use as horseshoes without sacrificing the wear capability of metal shoes, and are much easier to fit to the hoof. In particular, a polyurethane plastic such as the product described in US. Patent No. 3,214,- 411, issued on Oct. 26, 1965, has been found desirable. A material which has been successfully used is a commercially available product of Mobay Chemical Company, Pittsburgh, Pa., known as Texin 480-A.

The body of the shoe includes a generally arcuate forward portion 12 and the usual inwardly curving rear portions 14 which are shaped generally to the contour of a hoof. A protective flange 15 is formed as an integral upwardly extending part, tapering up and inwardly as shown in FIG. 6, and extending around the forward edge of the shoe, preferably back around the sides for a substantial distance as shown in FIG. 2. This flange engages around the periphery of the hoof and extends partially up the outer surface of the hoof to cover the peripheral edge thereof. The rear sections of the shoe are joined by a crossbar 18, preferably including a narrower neck portion 20, which may be cut and trimmed to provide for shaping and adjustment of the spacing of the rear portions 14. When such trimming is necessary, the separated part of the crossbar are joined by a split metal ring 22 (see FIG. 10) which is usually known as a hog ring. As will be explained, by drawing this ring tighter, the separated parts of the crossbar can be adjusted toward each other to fit the rear portions of the shoe precisely to the hoof.

Inside the flange 15, formed in the top of hoof surface of the shoe, there are a number of small cavities 24 and a channel 25 which extends around the front and sides of the shoe, generally inward from and coextensive with the flange 15. This channel has been found particularly useful for retaining a quantity of lubricating fluid, such as lanolin or other hoof lubricating compounds, which is beneficial to the horny structure of the hoof. For example, the fluid can be inserted into this channel periodically by the use of a hypodermic needle and syringe, since a sufiiciently sharp needle will penetrate the body of the shoe without harming it.

At the toe of the shoe there is a downwardly extending elongated toe cleat 27, and at the toe and along the sides a number of smaller bar-like extensions or ridges 28 form additional gripping surfaces for improved traction. Under some conditions, it is desirable to incorporate elongated cleats 30, and a number of these are shown extending from the lower or ground surface of the shoe. Where these cleats (or the toe cleat) are not desired, they can readily be omitted from the shoe during the molding process, simply by plugging the mold cavities for the cleats. Furthermore, the cleats can readily be trimmed by a sharp nipping tool, thereby enabling the shoer to adjust the height of the cleats, as for purposes of correcting an irregular gait tendency of the horse.

On the ground surface of the rear portions 14 there are pads 32 which include a raised crisscross pattern of traction surface. This type of construction is preferred for front shoes, or for rear shoes where there is no exceptional demand for good traction. Particularly in those cases where additional traction is needed, as with jumping horses, calks 35 can be formed in the area of these pads, as shown in the modified form of shoe in FIG. 7. The calks have a tapered prow or front 37 to minimize the drag that the calks may cause during running. This shoe incorporates the small traction ribs 28, but omits the cleats, since experience has indicated that these usually are unnecessary on the type of shoe which requires a raised calk. A section through the elongated calk is shown in FIG. 8.

The shoes are provided with a number of nail holes 40, and the resilient plastic material of the shoe has embedded in it, at the time it is molded, one or more thin metal retaining plates 42. These plates are formed with apertures corresponding to the nail holes, and are located in the sides and toe of the shoe. The plates are out lined in dotted lines in FIG. 2, and are shown in crosssection in FIGS. 5 and 6. The plate at the toe portion of the structure is in the nature of a thin metal Washer. The purpose of these plates is to assist in holding the shoes in place when the shoe is in use, because in many instances shoers may prefer to apply these shoes to the hoof by nails, in accordance with the conventional and presently known practice with which they are familiar.

It should be recognized, as mentioned, that there are a number of well-known disadvantages to the use of nails for this purpose. If the nails are not properly applied, they can cause substantial damage to the hoof. One or more nails can be loosened and then forced into the hoof creating injury, or upon being loosened the nails may eventually permit the shoe to work loose to the point where it is thrown, with possible injury to both the horse and anyone around. It has been found that nails used to hold shoes as disclosed herein will grip in the apertures in the plates 42, but due to the nature of the material of the body of the shoe, these metal plates can move somewhat in the shoe, with the result that there is a possibility for limited shock absorbing movement between the nails and the actual body of the shoe, reducing the tendency to loosen the nails under shock, and reducing the tendency to transmit shock from the nails into the hoof. Therefore, even when applied with nails, it has been found that the shoes disclosed herein have substantial advantages over metallic and similar shoes such as disclosed in the beginning of this specification.

The invention also relates to a novel method and apparatus for applying the shoes, such as described above, directly to the hoof of the animal, by means of a suitable adhesive. A commercially available adhesive known as Estain, available from B. F. Goodrich Company, has been suitably employed for attaching the shoes to the hoof, without use of nails. Another adhesive which has been found suitable is known as Plibond, available from Goodyear Tire and Rubber Company. Since the adhesives require some time to set, it is desirable to clamp the shoe into engagement with the hoof for a sufficient time to permit the adhesive to set, after which the clamping structure can be removed.

A novel clamp for this purpose is shown at FIGS. '9 and 10. It includes a front hinge structure provided by a pair of bars 50 which are joined through pins 52 to swinging side clamp members 54. These members have upwardly and inwardly curved retainer pieces 55 fastened to them, and adapted to extend upwardly around the flange 15' to hold it against the hoof. One of the side members 54 has the retainer bar member 58 attached to it by a hinge pin 59. The member 58 is hollow, for example by a construction of parallel plates or the like, and at its other end there is an internally threaded block 60 receiving a threaded thumbscrew or bolt 62. The base of this bolt engages the outer side of the other clamp member 54, thereby providing an adjustable arrangement which can squeeze the side members of the clamp around the shoe and against the hoof. With the bolt released, the member 58 can swing outwardly and the sides of the clamp can in turn swing Open, as shown in FIG. 10, to release clamp structure from the hoof.

In a typical operation, the neck 20 of the crossbar 18 can be cut and trimmed, if needed, the hog ring 22 inserted and tightened, and the adhesive applied to the bottom of the hoof and/or to the hoof surface of the shoe. Preferably, the adhesive is applied to the shoe so that it can be forced into the small cavities 24, while keeping the adhesive out of the lubricating channel 25. If desired, lubricant can be applied to this channel at the same time, particularly if it is sufficiently viscous to remain in the channel while the shoe is applied.

The shoe is then fitted to the hoof, including tightening of the hog ring as necessary, and the clamp is applied and the bolt tightened to hold the shoe in position on the hoof. The side members of the clamp may include one or more cleats 64 which would permit the animal to rest its foot on the ground temporarily with the clamp applied. Whether or not this is desirable will depend to some extent upon the nature and temperament of the animal, since it is of course necessary to avoid loosening or twisting of the clamp while the adhesive sets. Once the adhesive has set, the clamp structure can be removed, and the shoe will be bonded to the hoof without the need for nails, thereby eliminating any of the difiiculties and disadvantages that result from the use of nails. When it is time to replace the shoe, the shoe can be removed by trimming, as with a sharp instrument, together with the use of suitable solvent for the adhesive.

The present invention, therefore, provides novel shoes for hoofed animals, and methods of applying them, wherein a number of advantages are attained. The elastomeric material used in the construction of the shoes can readily be made sufficiently translucent to show any stones or other pieces of foreign matter that might work between the hoof and the shoe, and the shoe is flexible enough to allow such material to be removed. Where the shoes are applied solely through use of an adhesive, all of the disadvantages of nails are eliminated. Where nails are used, the fact that the nail engages the metal retainer plate embedded in the shoe provides a shock absorbing action between the nail and the shoe, and since the head of the nail can be recessed within the body of the shoe, no direct contact will normally occur between the nail and the ground.

The shoes are sufficiently resilient to provide shock absorption which is beneficial to the legs of the animal. In a number of cases, shoes constructed as described herein have been successfully applied to animals unable to run with metal shoes, and the usefulness of an expensive animal has been substantially prolonged. The cleats, in particular, can be trimmed to different heights to cause the hoof to move to one side or the other, and thus counteract an unusual gait or tractive pull of the animal. The toe cleat 27, in particular, is further beneficial in that it tends to stabilize the hoof and urges the hoof to clear the ground on the end of the stride. Under hard use, as in hard running of race horses, metal shoes will heat due to the abrasion and friction with the ground. This tends to drive the natural lubricant from the hoof, however it has been found that the shoe of synthetic material, as provided herein, does not have this tendency, and in addition the channel for an external supply of lubricant is provided to further condition the hoof.

The flange around the toe of the shoe, in particular, is beneficial in avoiding injury where a gaited horse strikes itself as in forging, cross firing, or other interferences. The flange covers the sharp edge of the hoof itself, and is sulficiently blunt and soft to avoid cutting. The structure of the ground surface of the shoes also is beneficial in that, because of some possible flexing of the shoe, it can clear itself of any collection of dirt or other foreign matter, and the extended cleats 30 can provide substantial shock absorption when the animal is required to walk or run over hard surfaces. The crossbar 18, in addition to providing for 6 accurate fitting of the shoes, also provides some protection for the frog of the hoof. In general, particularly with gaited animals, an improved and smooth stride has been observed with the use of these shoes.

While the methods herein described, and the forms of apparatus for carrying this method into effect, constitute preferred embodiments of the invention, it is to be understood that the invention is not limited to these precise methods and forms of apparatus, and that changes may be made in either without departing from the scope of the invention.

What is claimed is:

1. A horseshoe comprising a body of an elastomeric polyurethane plastic, said body including a main supporting member having a generally arcuate forward portion and inwardly curving rear portions shaped generally to the contour of a hoot, said portions having a hoof surface adapted to provide the main support for the hoof by fitting of said portions beneath the bearing surface of a hoof and also having a ground surface, a connecting bar having opposite ends formed integrally with said body and extending between said rear portions, said bar having a section adapted to be severed and trimmed to adjust the length of said bar to flex said rear portions toward each other to shape the curving rear portions of the body member into conformity with the shape of a hoof to which the shoe is fitted, and means for adjusting and holding the trimmed ends of said bar in adjoining relation beneath the hoof as the shoe is attached to the hoof.

2. A horseshoe as defined in claim 1 including an open channel formed in the upper surface of said body member and terminating short of the periphery of said body member and adapted to be located beneath the horny sole of the hoof for retaining a quantity of lubricating fluid placed in said channel and to maintain such fluid in contact with the sole of the hoof.

3. A horseshoe as defined in claim 1, including an insert member molded into said body member, a plurality of apertures formed in said insert member and including integral tangs of suflicient rigidity to bear against the sides of a nail passing through the aperture of the insert member to resist movement of the nail out of the body member once the nail has been inserted, and locating means formed on the bottom surface of said body member in alignment with said apertures in said insert members to align inserted nails with said apertures.

4. A horseshoe as defined in claim 1 including a plurality of depressions formed in the upper hoof engaging surface of said body member and adapted to receive a self-hardening adhesive for retaining the shoe on a hoof without nailing.

5. A horseshoe as defined in claim 1, including a plurality of tread members formed as protrusions from the bottom surface of said body member to provide a ground engaging surface with improved traction capabilities on the bottom surface of the shoe.

6. A horseshoe as defined in claim 5, wherein said tread members are constructed for trimming to different heights according to the need for compensation of the manner in which the animal places its hoof during running.

7. A horseshoe as defined in claim 1, including a protective flange extending upwardly and partially over said forward portion at least in the center thereof to engage the outer surface of the hoof and thus to cover the sharp lower edge at the forward part of the hoof.

8. The method of attaching to a hoofed animal a flexible shoe having an integral crossbar which can be varied in length to adjust the shape of the shoe to the bottom of the hoof, comprising (a) fitting the shoe to the bottom of the hoof and cutting the crossbar into parts of a length which brings the sides of the shoe into approximate conformity with the sides of the hoof,

(b) securing the parts of the trimmed crossbar to each other and adjusting the distances between them to retain the adjusted shape of the shoe,

(0) applying an adhesive to at least one of the surfaces of the shoe and the hoof to which the shoe is pp (d) then clamping the shoe to the hoof for a period suificient to allow setting of the adhesive, and

(e) then removing the clamp to leave the shoe attached to the hoof.

References Cited UNITED STATES PATENTS 3,026,636 3/1962 Fridrich 36-14 3,050,133 8/1962 Ketner et a1. 168-4 3,200,885 8/1965 Johnson 168-12 3,236,310 2/ 196 6 Quick 168-18 3,285,346 11/1966 Jenny et a1. 168-4 Renkenberger 168-4 Ward 168-4 Cooke 168-4 Jerome 168-27 Lowes 168-4 Wiesenfeld 168-11 Powlowski et a1. 168-20 Burnha-rn 36-14 Harsem 168-4 Nygaard 16 8-4 Anderson et a1. 168-4 Gash et a1. 168-4 Phalaner 168-14 U.S. Cl. X.R.

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