Patent Publication Number: US-2016219857-A1

Title: Horseshoe with metal clips

Description:
FIELD OF THE INVENTION 
     The present invention relates to horseshoes. More particularly, the present invention relates to a horseshoe with metal clips. 
     BACKGROUND OF THE INVENTION 
     A horse is born with hooves that are adapted to walking in its natural habitat. In nature, a horse may walk several types of ground surfaces and cover 30 km to 40 km a day. In this setting, the hoof is well adapted to the horse&#39;s needs, and such natural activity generally results in a hardened hoof. 
     A horse&#39;s hoof includes an outer cornified capsule that encapsulates an inner part that includes nerves, blood vessels, and bone. The hoof has sufficient flexibility to adapt to the ground surface. The hoof widens when contacting the ground, and its shape is adaptable to rocky or uneven ground. The lower central part of the hoof includes a softer region, or frog, that is connected to the horse&#39;s circulatory system. Pressure on the frog assists in pumping blood from the hoof toward the heart. 
     When horses were domesticated, the conditions of domestication diverged from these natural conditions. Human masters provided nourishment such that there was no longer a need for horses to roam about to find food. As a result, the hoof began to grow at a rate that was no longer balanced by daily wear. Also, as a result of the reduction in daily activity, the hoof of the domestic horse is softer and less protective of internal structure than that of the wild horse. 
     Since antiquity, horses have been utilized for work and warfare. Thus, at times, the horse was expected to perform strenuous tasks for a limited period of time. The hoof of the domestic horse could not withstand this stress. As a result, the metal horseshoe, nailed to the horse&#39;s hoof, was developed. Metal horseshoes were already known in Roman times, and the horseshoe substantially in its present form is at least 1000 years old. The horseshoe provided a solution to accommodate both the relatively sedentary daily life of the horse, and the occasional extreme demands of the horse. More recently, plastic horseshoes have been developed for veterinary purposes and for a limited number of other special uses. Plastic horseshoes may provide a degree of flexibility and cushioning. 
     SUMMARY OF THE INVENTION 
     There is thus provided, in accordance with an embodiment of the present invention, a horseshoe including: a blank that is shapeable to substantially conform to a contour of a hoof, the blank including a plurality of webs each having a thickness that is thinner than a thickness of an adjacent region of the blank; and a plurality of metal clips, each of the metal clips being shaped to attach to a web of the plurality of webs such that opposite plates of each of the clips sandwich at least a portion of the web to which that clip is attached, each of the opposite plates including a hole, each web being adaptable to enable the attachment of a clip of the plurality of metal clips such that when the horseshoe is aligned to the hoof, the holes on the opposite plates are substantially aligned with one another and with a white line of the hoof to enable driving of a nail through the holes and into the hoof at the white line. 
     Furthermore, in accordance with an embodiment of the present invention, the blank includes a substantially radial slit. 
     Furthermore, in accordance with an embodiment of the present invention, the blank is sufficiently transparent to enable discerning an indication of the white line via the blank when the blank is held against a bottom of the hoof. 
     Furthermore, in accordance with an embodiment of the present invention, each web is adaptable by trimming a distal end of that web or by placement of a slot that is cut on that web. 
     Furthermore, in accordance with an embodiment of the present invention, the blank includes plastic. 
     Furthermore, in accordance with an embodiment of the present invention, the opposite plates of the clip are each provided with a post that is configured to be inserted through a slot in a web of the plurality of webs. 
     Furthermore, in accordance with an embodiment of the present invention, an end of the clip is configured to be inserted through a slot in a web of the plurality of webs. 
     Furthermore, in accordance with an embodiment of the present invention, the end includes a tab that is insertable through a slot on a bendable plate of the clip, the tab being configured to spread laterally or bend to hold the tab in the slot. 
     Furthermore, in accordance with an embodiment of the present invention, the clip includes a projection such that, when the horseshoe is placed on a hoof, the projection extends upward outside of the hoof. 
     Furthermore, in accordance with an embodiment of the present invention, the clip includes a projection such that, when the horseshoe is placed on a hoof, the projection extends downward. 
     Furthermore, in accordance with an embodiment of the present invention, the projection includes a spike. 
     Furthermore, in accordance with an embodiment of the present invention, the horseshoe includes a metal clip without a hole for a nail. 
     There is further provided, in accordance with an embodiment of the present invention, a method of preparing a horseshoe for attachment to a hoof, the method including: preparing for attachment of a plurality of metal clips a blank that is shaped to cover a bottom of the hoof, the blank including a plurality of webs, each web for attachment of a metal clip of the plurality of metal clips being adapted such that when that clip is attached to that web and the blank is aligned with the hoof, a nail hole of the clip is substantially aligned with a white line of the hoof; and attaching each clip of the plurality of metal clips to a web of the plurality of webs. 
     Furthermore, in accordance with an embodiment of the present invention, preparing the blank includes marking an outer contour of the hoof on the blank when the blank is held to the hoof, and cutting the blank substantially along the marked outer contour. 
     Furthermore, in accordance with an embodiment of the present invention, preparing the blank includes marking a position of the white line of the hoof on the blank when the blank is held to the hoof, and trimming each web of the plurality of webs in accordance with the marked position. 
     Furthermore, in accordance with an embodiment of the present invention, preparing the blank includes marking a position of the white line of the hoof on the blank when the blank is held to the hoof, and cutting a slot into each web of the plurality of webs in accordance with the marked position. 
     Furthermore, in accordance with an embodiment of the present invention, attaching each clip includes insertion of two substantially parallel end plates of the clip through a corresponding two slots in a web of said plurality of webs, and bending one of end plates. 
     Furthermore, in accordance with an embodiment of the present invention, attaching each clip includes insertion of an end plate of that clip through a slot in a web of the plurality of webs and closing a bendable plate such that a tab on the end plate is inserted through a slot in the bendable plate. 
     Furthermore, in accordance with an embodiment of the present invention, the method includes attaching each clip, which includes applying a tool to laterally spread the tab or bending the tab to hold the tab in the slot. 
     Furthermore, in accordance with an embodiment of the present invention, the method includes attaching a metal clip without a nail hole to an additional web of the blank. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In order for the present invention, to be better understood and for its practical applications to be appreciated, the following Figures are provided and referenced hereafter. It should be noted that the Figures are given as examples only and in no way limit the scope of the invention. Like components are denoted by like reference numerals. 
         FIG. 1  schematically illustrates a plastic and metal horseshoe, in accordance with an embodiment of the present invention. 
         FIG. 2A  schematically illustrates a face of a plastic horseshoe blank for the horseshoe shown in  FIG. 1 . 
         FIG. 2B  schematically illustrates a side view of the plastic horseshoe blank shown in  FIG. 2A . 
         FIG. 3A  is a schematic perspective view of fitting the plastic horseshoe blank of  FIG. 2A  to a hoof. 
         FIG. 3B  is a schematically illustrates marking the plastic horseshoe blank of  FIG. 2A  to indicate structure of the hoof relative to the blank. 
         FIG. 4  schematically illustrates the plastic horseshoe blank of  FIG. 3B  after shaping. 
         FIG. 5  schematically illustrates the plastic horseshoe blank of  FIG. 4  prepared for attachment of metal clips. 
         FIG. 6A  schematically illustrates attachment of a metal clip to the plastic horseshoe blank of  FIG. 5 . 
         FIG. 6B  is a schematic sectional view of preparing the metal clip shown in  FIG. 6A  for attachment to the plastic horseshoe blank. 
         FIG. 6C  is a schematic side view of the metal clip in  FIG. 6B  while open and in place on the plastic horseshoe blank. 
         FIG. 6D  is a schematic side view of the metal clip of  FIG. 6C  after closing. 
         FIG. 7A  is a schematic illustration of a metal clip for locking into by use of a tool, in accordance with an embodiment of the present invention. 
         FIG. 7B  shows a variation of the metal clip of  FIG. 7A , with an upward projection. 
         FIG. 7C  shows a variation of the metal clip of  FIG. 7A , with a downward projection. 
         FIG. 7D  shows a variation of the metal clip of  FIG. 7C , with a downward-projecting spike. 
         FIG. 8  shows a slit horseshoe blank, in accordance with an embodiment of the present invention. 
         FIG. 9A  schematically illustrates a metal clip for insertion through two slots in a horseshoe blank, in accordance with an embodiment of the present invention. 
         FIG. 9B  schematically shows a horseshoe blank that is adapted for attachment of the metal clip shown in  FIG. 9A . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be understood by those of ordinary skill in the art that the invention may be practiced without these specific details. In other instances, well-known methods, procedures, components, modules, units and/or circuits have not been described in detail so as not to obscure the invention. 
     Although embodiments of the invention are not limited in this regard, discussions utilizing terms such as, for example, “processing,” “computing,” “calculating,” “determining,” “establishing”, “analyzing”, “checking”, or the like, may refer to operation(s) and/or process(es) of a computer, a computing platform, a computing system, or other electronic computing device, that manipulates and/or transforms data represented as physical (e.g., electronic) quantities within the computer&#39;s registers and/or memories into other data similarly represented as physical quantities within the computer&#39;s registers and/or memories or other information non-transitory storage medium (e.g., a memory) that may store instructions to perform operations and/or processes. Although embodiments of the invention are not limited in this regard, the terms “plurality” and “a plurality” as used herein may include, for example, “multiple” or “two or more”. The terms “plurality” or “a plurality” may be used throughout the specification to describe two or more components, devices, elements, units, parameters, or the like. Unless explicitly stated, the method embodiments described herein are not constrained to a particular order or sequence. Additionally, some of the described method embodiments or elements thereof can occur or be performed simultaneously, at the same point in time, or concurrently. Unless otherwise indicated, us of the conjunction “or” as used herein is to be understood as inclusive (any or all of the stated options). 
     In accordance with an embodiment of the present invention, a horseshoe includes a horseshoe blank that may be shaped to be fitted to a hoof of a horse or other animal A plurality of metal clips may be firmly attached to the horseshoe blank. For example, the horseshoe may be made of plastic or another lightweight material (e.g., wood, cardboard, or another suitable material). The material used for the horseshoe blank may be lighter, more flexible, and more transparent than a similarly sized and shaped metal object. The material used for the horseshoe blank may be cut or shaped using tools typically design for work on plastic or wood, without need for tools designed especially for working with plastic. 
     When the clips are attached, at least a portion of the horseshoe blank is sandwiched between opposite plates of the metal clip (e.g., upper and lower plates when the horseshoe is attached to a hoof of an animal that is standing erect). The metal clips include a pair of aligned nail holes on the upper and lower plates of the metal clip. The metal clips may be attached to the horseshoe blank such that when the resulting horseshoe is placed on the hoof, the nail holes are aligned with the white line of the hoof. As used herein, a nail hole is aligned with the white line when the nail hole is positioned at a point relative to the white line where the farrier or other person shoeing the hoof intends to drive a nail. The point is typically on the white line or near (e.g., within 5 mm, or in some cases within 2 mm of) the white line. Nails may be driven via nail holes through the plates and the sandwiched portion of the horseshoe blank into the hoof at the white line. As used herein, a position at the white line or water line refers to a position on or near (e.g., within 2 mm of) the white line or water line of the hoof. Other clips that are attached to the horseshoe blank may serve purposes other than attachment of the horseshoe to the hoof. Such other clips may not include nail holes. 
     A horseshoe in accordance with an embodiment of the present invention may provide solutions to problems with both metal and plastic horseshoes. 
     Traditional metal (typically iron or steel) horseshoes provide good protection to the hoof against injury and wear. However, the rigidity of the metal horseshoe prevents the hoof in adjusting its shape in accordance with the hoof&#39;s natural flexibility. Thus, a metal horseshoe may prevent the hoof from properly adapting to different ground surface conditions. The rigidity may also transfer the shock of contact with the ground to the horse&#39;s leg and body. Since a metal horseshoe typically raises the frog of the hoof, and since the rigidity of the metal horseshoe prevents the horseshoe from bending or deforming upon contact with the ground, the frog may be prevented from contacting the ground. When the frog is prevented from contacting the ground, proper operation of the horse&#39;s circulatory system may be interfered with. 
     A plastic horseshoe, by being more flexible than a metal horseshoe, could, in principle, solve these problems. However, a typical plastic horseshoe is not sufficiently strong to be held in place by a nail. Thus, typically, a plastic horseshoe is glued to the hoof. Such gluing may be suitable only for short-term situations, or where the horse is not expected to be active. Alternatively, a plastic horseshoe may be configured to fit over the hoof. Since plastic may not be bent in the same manner as metal, fitting a plastic horseshoe may involve custom production (e.g., molding) to size and special shoeing techniques. Such custom production of a plastic horseshoe may be very expensive. The alternative, stocking a large number of different sizes of plastic horseshoes, may be impractical for a farrier. 
     A horseshoe blank in accordance with an embodiment of the present invention, may provide the flexibility of a plastic horseshoe, and enable the hoof to react more naturally to ground conditions an impact with the ground than would a metal horseshoe. On the other hand, the metal clips with nail holes enable attachment to the hoof with nails. Some or all of the clips may be configured to provide (increased resistance to wear over a plastic horseshoe. 
       FIG. 1  schematically illustrates a plastic and metal horseshoe, in accordance with an embodiment of the present invention. 
     Horseshoe  10  is configured to fit on hoof  20 . Horseshoe  10  includes an adapted horseshoe blank  52  made of a plastic. A plurality of metal clips  30  are attached to clip attachment webs  12  of adapted horseshoe blank  52 . Some or all of metal clips  30  may include nail holes  38 . Nails  56  may be driven through nail holes  38  to attach horseshoe  10  to (e.g., at a white line or water line of) hoof  20 . Typically, when a metal clip  30  is attached to adapted horseshoe blank  52 , an upward-facing (e.g., configured to face the bottom of hoof  20 ) surface of the metal clip  30  is substantially flush with an upward-facing surface of adapted horseshoe blank  52 . A downward-facing (e.g., configured to contact the surface on which hoof  20  and horseshoe  10  are resting) surface of metal clip  30  may be recessed (e.g., by a few millimeters, typically less than 1 centimeter) from a downward-facing surface of adapted horseshoe blank  52 . A central hole  16  of horseshoe  10  may reduce the weight and increase flexibility of horseshoe  10 . 
     Horseshoe  10  may be prepared from a horseshoe blank that is modified to fit a particular hoof and to which metal clips  30  are attached. 
       FIGS. 2A-6D  present stages in preparing a horseshoe  10  for attachment to a hoof. 
       FIG. 2A  schematically illustrates a face of a horseshoe blank for the horseshoe shown in  FIG. 1 .  FIG. 2B  schematically illustrates a side view of the horseshoe blank shown in  FIG. 2A . 
     Horseshoe blank  11  may be initially in the form of a disk, as shown. The diameter of horseshoe blank  11  may be sufficiently large to cover a large variety of hoof sizes. For example, horseshoe blank  11  may have a diameter of about 160 mm, or another suitable size. Several different sizes of horseshoe blank  11  may be designed for different horse breeds, groups of horse breeds, or other animals that may benefit from shoeing. Alternatively or in addition, a horseshoe blank may be initially in another form that is at least as large as the hoof to which the horseshoe blank is to be fitted. 
     Horseshoe blank  11  may be constructed of a plastic. For example, the plastic may include polyurethane, a polyurethane compound, reinforced polyurethane, rubber, or another plastic that provides the required or desired flexibility, durability, or other property. The material of which horseshoe blank  11  is constructed may be transparent, semitransparent (e.g., colored or tinted), or translucent. The transparency or translucency of horseshoe blank  11  may be such as to enable at least blurred viewing of structure of a hoof, or an indication of structure of the hoof (such as the outer contour, the frog, and the white line) through horseshoe blank  11  when horseshoe blank  11  is placed on the hoof for fitting. Typically, an indication of the white line may include coloring or darkening, e.g., with a dark marker, or with a color or substance that is readily discerned. Thus, the position of the white line may be discerned via horseshoe blank  11  during fitting. 
     Horseshoe blank  11  includes a plurality of thin webs in the form of clip attachment webs  12 . The thickness of each clip attachment web  12  is thinner than that of an adjacent separation section  15  or web-less region  14 , or of other adjacent region, section, or structure of horseshoe blank  11 . Lateral sides  12   a  and  12   b  of each web structure may be substantially parallel. Each clip attachment web  12  extends to the outer perimeter of horseshoe blank  11 . 
     Each clip attachment web  12  may be adapted by a farrier to enable attachment of a metal clip  30  ( FIG. 1 ). Each clip attachment web  12  is formed between an upper web groove  17   a  and a lower web groove  17   b . Typically, upper web groove  17   a  may be similar or substantially equal to lower web groove  17   b . Each clip attachment web  12  may be oriented in a general radial direction. In some cases, some or all of the web structures may be oriented at an oblique angle to the radial direction. 
     Horseshoe blank  11  may include one or more web-less regions  14 . For example, a web-less region  14  may be configured for placement on a part of the hoof, (e.g., front or back part) to which a horseshoe  10  ( FIG. 1 ) need not, or should not, be attached with nails. 
     Horseshoe blank  11  may include a central hole  16 . For example, central hole  16  may be configured for placement over a frog of the hoof. 
     In order to form a horseshoe  10  that incorporates horseshoe blank  11 , horseshoe blank  11  may be adapted to a particular hoof. For example, a father cut horseshoe blank  11  to match a contour of the hoof. Prior to cutting, horseshoe blank  11  be fitted to the hoof. For example, horseshoe blank  11  may be marked to indicate an outline of the outer perimeter of the hoof, and a position of the white line of the hoof (along which nails to hold horseshoe  10  to the hoof are typically driven), relative to horseshoe blank  11  (e.g., after marking or coloring the white line to increase its visibility via horseshoe blank  11 ). 
       FIG. 3A  is a schematic perspective view of fitting the horseshoe blank of  FIG. 2A  to a hoof. 
     A hoof  20  may be placed on a horseshoe blank  11  for fitting. During the fitting, horseshoe blank  11  may located and oriented relative to the hoof as would the final horseshoe. Thus, web-less regions  14  may be oriented along a frontward-backward direction relative to hoof  20 . Hoof  20  may be placed on horseshoe blank  11  such that the frog of hoof  20  may be fully or partially placed over central opening  16  of horseshoe blank  11 . 
     With hoof  20  placed on horseshoe blank  11 , an outline of the outer perimeter of hoof  20  may be marked on horseshoe blank  11 . For example, a marker, pencil, pen, crayon, or other writing, drawing, or marking instrument may be used to trace the outline of hoof  20  onto horseshoe blank  11 . 
       FIG. 3B  is a schematically illustrates marking the horseshoe blank of  FIG. 2A  to indicate structure of the hoof relative to the blank. 
     Hoof contour line  21  represents the outer contour of hoof  20  marked on horseshoe blank  11 . With hoof  20  lifted, horseshoe blank  11  may be placed on hoof  20  such that hoof contour line  21  is aligned with the outer perimeter of hoof  20  as viewed via horseshoe blank  11 . White line indication line  22  may be drawn to indicate an approximate position of the white line of hoof  20  relative to horseshoe blank  11 . 
     Alternatively to physical marking of the contour, digital or computerized marking may be utilized. For example, images of hoof  20  may be acquired by one or more image acquisition devices (e.g., digital cameras) from one or more directions (e.g., from above the hoof and from below the hoof). One or more length references (e.g., a transparent ruled surface placed on or below the hoof when acquiring the images) may enable correct scaling of a digital representation of the hoof. An appropriately configured processor may then digitally superimpose one or more structures of hoof  20  (e.g., an outer contour and white line of hoof  20 ) on a digital rendering of horseshoe blank  11 . 
     After horseshoe blank  11  is marked, horseshoe blank  11  may be cut to at least cover the bottom of hoof  20 . For example, horseshoe blank  11  may be cut along, or outside (e.g., by a small distance, e.g., about 5 millimeters, or less than one or two centimeters, or by a longer distance, outside of) hoof contour line  21 . For example, horseshoe blank  11  may be cut along or outside of hoof contour line  21  using a handheld saw (manual or mechanical), mechanical saw (e.g., jigsaw) or mill, or a computerized machining device (e.g., on the basis of a digital representation of horseshoe blank  11  and hoof contour line  21 ), or another suitable cutting or shaping device. 
       FIG. 4  schematically illustrates the horseshoe blank of  FIG. 3B  after shaping. 
     The outer boundary  24  of shaped horseshoe blank  50  lies outside of hoof contour line  21 . 
     After shaping of shaped horseshoe blank  50 , clip attachment webs  12  may be adapted for attachment of metal clips. Each clip attachment web  12  to which a metal clip is to be attached may be modified such that when the resulting horseshoe is placed on a hoof, nail holes in the metal clip are approximately aligned with the white line of the hoof. 
     The adaptation of shaped horseshoe blank  50  may include trimming a distal (to shaped horseshoe blank  50 ) end of each clip attachment web  12  to enable placement of the metal clip at the required point on that clip attachment web  12 . A hole may be drilled or punched through clip attachment web  12  to accommodate one or more attachment posts of the metal clip. 
       FIG. 5  schematically illustrates the horseshoe blank of  FIG. 4  prepared for attachment of metal clips. 
     In adapted horseshoe blank  52 , a trimmed distal end  13  of each clip attachment web  12  has been formed. The amount of trimming of trimmed distal end  13  is such to enable placement of a metal clip on clip attachment web  12  such that nail holes of the metal clip are substantially aligned with white line indication line  22 . A post slot  26  has been cut (e.g., punched, drilled, machined, or otherwise cut) through each clip attachment web  12 . The size and shape of post slot  26  is such as to enable passage of one or more attachment posts of the metal clip. For example, in some cases post slot  26  may extend across all or most of the width of clip attachment web  12 . 
     Clip attachment webs  12  to which no metal clip is to be attached need not be trimmed and need not have a post hole formed. 
     For example, one or more tools may be provided to adapt a clip attachment web  12  for attachment of a metal clip. Such a tool may include a mark, viewing hole, or other positioning aid for placement at a point of the tool along white line indication line  22 . The tool may include a knife for trimming web structure  13  at trimmed distal end  13 , a punch for forming post slot  26 , or both. Operating the tool when properly positioned relative to white line indication line  22  may trim clip attachment web  12  to form a properly positioned trimmed distal end  13 , may form post slot  26 , or both. For example, the tool may have a form similar to that of cutting pliers. 
     As another example, clip attachment web  12  may be manually marked at positions where trimmed distal end  13  and post slot  26  are to be formed. A stencil-like guide tool may be provided to assist in the marking. Standard cutting or trimming tools (e.g., cutting pliers, saw, mill, or other tool) and hole-forming tools (e.g., hole punch, drill, awl, or other tool) may then be applied to the marked positions to form trimmed distal end  13  and post slot  26 . As another example, a digitally controlled shaping machine may automatically form trimmed distal end  13  and post slot  26 , e.g., concurrent with, or separately from, shaping of shaped horseshoe blank  50  ( FIG. 4 ). As another example, three-dimensional printing techniques may be applied to directly produce adapted horseshoe blank  52 . 
     After preparation of adapted horseshoe blank  52 , metal clips may be attached to clip attachment webs  12 . 
       FIG. 6A  schematically illustrates a metal clip attached to the horseshoe blank of  FIG. 5 . 
     Metal clips  30  may be attached to clip attachment webs  12  of adapted horseshoe blank  52 . Attachment of metal clips  30  to adapted horseshoe blank  52  is such that nail holes  38  of metal clips  30  are approximately aligned with white line indication line  22 . 
       FIG. 6B  is a schematic sectional view of attachment of a metal clip shown in  FIG. 6A  for attachment to the horseshoe blank.  FIG. 6C  is a schematic side view of the metal clip in  FIG. 6B  while open and in place on the horseshoe blank. 
     Metal clip  30  includes a bendable plate  40  and a fixed plate  42  connected by end plate  48 . Metal clip  30  may be made of iron, various types of steel (e.g., varying in hardness or elasticity), aluminum, copper or copper alloys, or another suitable metal. The thickness may be less than about one half of a centimeter, e.g., about 2 mm A shape and width of metal clip  30  may be such as to fit within a clip attachment web  12 . The fit may be such that the lateral walls of clip attachment web  12  constrain or prevent lateral motion of metal clip  30  within clip attachment web  12 . 
     Typically, bendable plate  40  is attached to clip attachment web  12  so as to face downward when attached to a hoof. Thus, in this case, fixed plate  42  may be placed into upper web groove  17   a  ( FIG. 1 ) and bendable plate  40  may be placed into lower web groove  17   b . In some cases, the positions of bendable plate  40  and fixed plate  42  may be reversed. The thicknesses of bendable plate  40  and fixed plate  42  may be approximately the same, or one may be thicker than the other. For example, when fixed plate  42  is placed into upper web groove  17   a , the thickness of fixed plate  42  may be approximately equal to the depth of upper web groove  17   a . The thickness of bendable plate  40  may be less (e.g., by a few millimeters) than the depth of lower web groove  17   b , approximately equal to the depth of lower web groove  17   b , or in some cases, more (e.g., by a few millimeters) than the depth of lower web groove  17   b  (e.g., depending on a purpose of the metal clip, as described below in connection with  FIGS. 7B-7D ). Bendable plate  40  may be bendable relative to end plate  48  at connection  46 . 
     A surface of metal clip  30  that is designed to face downward (e.g., of bendable plate  40 ) when the resulting horseshoe is attached to the hoof may be adapted to particular circumstances. For example, the surface may be roughened, spiked, provided with a layer of a material, or otherwise adapted to increase traction on one or more types of ground. One or more projections may extend upward to provide additional protection to sides of the hoof. The downward facing surface may have sufficient thickness so as to be flush with a downward facing surface of (e.g., of separation section  15  or web-less section  14  of) adapted horseshoe blank  52 . 
     Initially, attachment post  34   a  of fixed plate  42  may be inserted through post slot  26  of clip attachment web  12 . When so inserted, trimmed distal end  13  of clip attachment web  12  may abut end plate  48  of metal clip  30  and nail hole  38   a  of fixed plate  42  may be approximately aligned with white line indication line  22 . 
     Bendable plate  40  may be bent about connection  46  to lower bendable plate onto clip attachment web  12 . When so bent, attachment post  34   b  of bendable plate  40  may be inserted with insertion motion  44  into post slot  26 . Bendable plate  40  may be sufficiently flexible to enable insertion of attachment post  34   b  into post slot  26 . 
     Typically, attachment post  34   b  is inserted into a post slot  26  into which attachment post  34   a  has already been inserted. Thus, locking structure  36   b  on attachment post  34   b  may engage cooperating locking structure  36   a  on attachment post  34   a . The engagement of locking structure  36   b  with cooperating locking structure  36   a  may prevent opening of metal clip  30 . Alternatively or in addition, nailing of metal clip  30  to a hoof via nail holes  38   a  and  38   b  may hold metal clip  30  to the hoof, and prevent opening of metal clip  30 . 
       FIG. 6D  is a schematic side view of the metal clip of  FIG. 6C  after closing. 
     After closing metal clip  30 , part of clip attachment web  12  is sandwiched between bendable plate  40  and fixed plate  42  of metal clip  30 . Metal clip  30  is held to clip attachment web  12  by attachment posts  34   a  and  34   b . After closing metal clip  30 , nail hole  38   b  of bendable plate  40  may be aligned with nail hole  38   a  of fixed plate  42 . 
     A sufficient number of metal clips  30  may attached to adapted horseshoe blank  52  to enable nailing of the resulting horseshoe  10  ( FIG. 1 ) to a hoof  20 . For example, the number of metal clips  30  to be attached may be determined (e.g., by a farrier or other person shoeing, or overseeing or assisting with shoeing) on the basis of the anticipated activity of the horse being shoed. 
     After attachment of metal clips  30 , the resulting horseshoe  10  may be nailed to a hoof  20 . For example, nails may be driven via aligned nail holes  38   a  and  38   b  into hoof  20  at the white line of hoof  20 . After shoeing, an outer perimeter of adapted horseshoe blank  52  of horseshoe  10  may be filed, rasped, planed, or otherwise reshaped to closely match the outer contour of the hoof. 
     A metal clip of horseshoe  10  may be designed to be locked into place by separating adjacent posts with a tool. 
       FIG. 7A  is a schematic illustration of a metal clip for locking into place by use of a tool, in accordance with an embodiment of the present invention. 
     End plate  68  of metal clip  60  is designed to be inserted through a post slot (e.g., spanning the width of) a clip attachment web of an adapted horseshoe blank. When bendable plate  40  is closed, tab  62 , which includes tab slit  66 , may be inserted through tab slot  64 . After tab  62  has been inserted through tab slot  64 , a wedge or other suitable tool may be applied to (e.g., inserted into and hammered or otherwise forced into) tab slit  66 . The action of the tool may laterally spread tab  62  (e.g., laterally separate two adjacent parts of tab  62 ). The lateral spreading holds tab  62  in tab slot  64 , and may thus lock bendable plate  40  to end plate  68  to prevent opening of metal clip  60 . Alternatively or in addition, tab  62  may be bent (e.g., toward the center of the adapted horseshoe blank, or otherwise bent) in order to hold tab  62  in tab slot  64  and close metal clip  60 . 
     Such locking may be durable even when no nail is nailed through nail holes  38 . Thus, variations of metal clip  60  (such as are shown in  FIGS. 7B-7C ) may or may not include nail holes  38 . Such variations may include various types of projections. The projections may be constructed of the same material as the remainder of the metal clip, or may be made of another metal or material (e.g., ceramic, plastic, or other material) with properties (e.g., hardness, rigidity or flexibility, elasticity, durability under various conditions, resistance to corrosion, coefficient of friction, or another property) that are suitable to a particular purpose (e.g., protection from bumping, increasing traction, protection from wear or breakage, or another purpose). 
       FIG. 7B  shows a variation of the metal clip of  FIG. 7A , with an upward projection. 
     When a horseshoe that incorporates metal clip  70  is attached to a hoof, upward projection  72  may extend upward outside of and around the outer perimeter of the hoof. Upward projection  72  may protect the hoof from side impacts. Upward projection  72  may serve to assist in holding in place on the hoof a horseshoe that incorporates metal clip  70 . 
       FIG. 7C  shows a variation of the metal clip of  FIG. 7A , with a downward projection. 
     Downward projection  82  of metal clip  80  when incorporated into a horseshoe and attached to a hoof may be configured to provide one or more benefits. For example, downward projection  82  may be configured (e.g., by include a hard metal) to provide protection of the horseshoe against wear due to contact with the ground. A downward facing face of downward projection  82  may include structure (e.g., a roughened or otherwise prepared surface) or materials (e.g. a material with a high coefficient of friction for contact with the ground) that increase traction or provide additional protection against slipping. 
       FIG. 7D  shows a variation of the metal clip of  FIG. 7C , with a downward-projecting spike. 
     A downward projection in the form of spike  84  may be configured to engage the ground when metal clip  80  is incorporated into a horseshoe on a hoof, and may thus provide increased traction. 
     Variations of horseshoe blank  11  ( FIG. 2A ) may be configured to have various properties. For example, a variation of horseshoe blank  11  may be configured to have increased flexibility, thus enabling enhanced adaption of the horseshoe, and the hoof, to varying terrain. For example, a horseshoe blank may be provided with a slit that enables adaption to variations in a surface. 
       FIG. 8  shows a slit horseshoe blank, in accordance with an embodiment of the present invention. 
     Slit horseshoe blank  90  is provided with radial slit  92 . Radial slit  92  may enable relative movement between adjacent sections  94 . The relative movement may enable a horseshoe that incorporates slit horseshoe blank  90  to adapt to variations in local surface topography (e.g., when the hoof steps on a stone, object, or bump). The adaptation of the horseshoe to the variations in topography may enable, to at least a limited extent, the natural adaptation of the hoof to such variations. 
     In accordance with an embodiment of the present invention, a horseshoe blank may be adapted for attachment of a metal clip by forming two post slots in a clip attachment web of the blank. The metal clip may be initially shaped for insertion through the two post slots. 
       FIG. 9A  schematically illustrates a metal clip for insertion through two slots in a horseshoe blank, in accordance with an embodiment of the present invention.  FIG. 9B  schematically shows a horseshoe blank that is adapted for attachment of the metal clip shown in  FIG. 9A . 
     Metal clip  100  includes initially substantially parallel walls, end plate  68  and bendable end plate  102 . Adapted horseshoe blank  110  includes two parallel post slots  26  on each clip attachment web  12  that has been adapted for attachment of a metal clip  100 . The positions of post slots  26  on each adapted clip attachment web  12  correspond to those of end plate  68  and bendable end plate  102  or metal clip  100 . The spacing between post slots  26  on each adapted clip attachment web  12  is substantially equal to the perpendicular distance between end plate  68  and bendable end plate  102  of metal clip  100 . Thus, end plate  68  and bendable end plate  102  may be simply inserted through post slots  26 . 
     The attachment may be completed by bending bendable end plate  102  substantially along bending line  104  with bending motion  106 . Bending along bending line  104  may be facilitated by one or more slots  108  along bending line  104 . Metal clip  100  may be closed by insertion of tab  62  through tab slot  64  and bending or otherwise securing tab  62  within tab slot  64 . 
     The radial positions of post slots  28  on clip attachment web  12  are selected such that nail holes  38  are aligned with a white line indication line  22 . Since a bendable end plate  102  is inserted through a post slot  28  in clip attachment web  12  (and not around a distal end of clip attachment web  12 ) there is no need to trim to size a distal end of clip attachment web  12 . 
     For example, a tool for preparing a horseshoe blank for attachment of metal clip  100  may include a window or other arrangement to enable alignment of the tool with white line indication line  22 . The tool may include a double punch or other component for formation of two post slots  28 . The post slots  28  are formed with a spacing and position to enable concurrent insertion of end plate  68  and bendable end plate  102  and alignment of nail holes  38  with white line indication line  22 . 
     Different embodiments are disclosed herein. Features of certain embodiments may be combined with features of other embodiments; thus certain embodiments may be combinations of features of multiple embodiments. The foregoing description of the embodiments of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. It should be appreciated by persons skilled in the art that many modifications, variations, substitutions, changes, and equivalents are possible in light of the above teaching. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention. 
     While certain features of the invention have been illustrated and described herein, many modifications, substitutions, changes, and equivalents will now occur to those of ordinary skill in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.