Abstract:
A tailset crupper for an animal, such as a horse, may be made from a solid casting without lightening features, such as to produce a heavier, less easily dislodged object, such as may have a lower center of gravity, and a center of gravity located closer to the surface of the animal. The trough of the crupper may be predominantly open from below. The distal end of the crupper may have a large curl the bends on a large angle partially back toward the horse. The crupper may be substantially spoonless. That is, the protrusion at the front end of the crupper may be small, and may by shy of the cushioning on either side.

Description:
This application claims the benefit under 35 USC 120 as a continuation-in-part of U.S. patent application Ser. No. 14/073,253 filed Nov. 6, 2013, the specification and drawings thereof being incorporated in their entirety herein by reference. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to tail set cruppers. 
     BACKGROUND OF THE INVENTION 
     A tail set crupper is a portion of a harness for an animal, such as a horse, that is used to encourage the tail to be maintained in an arched shape. It may be worn by the animal for extended periods of time. After a period of use, the crupper may tend to cause the tail to be straightened relative to the direction of the spine of the animal, and also to extend on a relatively upstanding, arcuate shape, such that the tail may take on the desired “set”, hence the “tail set” crupper. A horse, or other animal, may find the crupper uncomfortable. Consequently, the horse may make repeated efforts to dislodge the crupper. In the view of the present inventor, horses often are, or become, quite adept at dislodging the crupper. It might therefore be advantageous to have a crupper that might tend either to be more comfortable, or less easily dislodged, or both. The specification and drawings of U.S. Pat. No. 6,993,892 are incorporated herein by reference. 
     SUMMARY OF THE INVENTION 
     In an aspect of the invention there is a crupper. There is a base portion and a trough portion. The base portion has a first surface for placement next to the hindquarters of an animal. A trough portion is joined to the base portion. The trough portion, in use, extends outwardly away from the animal. The trough portion has a first end adjoining the base portion, a second end distant from the base portion and an intermediate portion between the first and second ends. The second end of the trough portion has a rounded mouth. The trough has a medial portion between the first end and the second end, the medial portion being predominantly downwardly open. 
     In a feature of the aspect of the invention, the trough portion has a spine extending therealong, and apertures are formed in the trough portion adjacent to the spine, the spine being narrower than the apertures. In another feature, the trough portion has a central spine and a cross-rib extending between the first end and the second end, and is otherwise downwardly open. In yet another feature, the rounded mouth defines a continuous imperforate rounded surface. In still another feature, the crupper has a central longitudinal plane, and the crupper has the rounded mouth presents a continuous rounded surface over a sweep in the central longitudinal plane of more than 2(Pi)/3 radians. In an additional further feature, the crupper has an outlet tangent portion extending away from the continuous rounded surface. 
     In a still further feature, the crupper is substantially spoonless. In another feature, the base portion and the trough portion are joined as parts of a single casting, the base portion including left and right hand pads located to either side of the first end of the trough. The first and second pads have a through-thickness measured to the trough. The first end of the trough extends a distance less than the through-thickness proud of the first and second pads. In another feature, the first end of the trough is free of upward slope deviation. 
     In another aspect of the invention there is a tail set crupper. It has a base portion and a trough portion. The base portion has a first surface for placement next to the hindquarters of an animal. The trough portion is immovably joined to the base portion, the trough portion, in use, extending outwardly away from the animal. The trough portion has a first end adjoining the base portion, a second end distant from the base portion and an intermediate portion between the first and second ends. The first end of the crupper being substantially spoonless. 
     In a feature of that aspect of the invention, the base portion has a through-thickness adjacent to the trough, and the first end of the trough extends a distance less than the through-thickness proud of the pads. In another feature, the base portion has cushioning applied thereto, and the cushioning stands proud of the first end of the trough. In another feature, the first end of the trough is free of upward slope deviation. In still another feature, the intermediate portion of the trough is downwardly vented. 
     In another aspect of the invention there is a tail set crupper. It has a base portion and a trough portion. The base portion has a first surface for placement next to the hindquarters of an animal. The trough portion is immovably joined to the base portion. The trough portion, in use, extends outwardly away from the animal. The trough portion has a first end adjoining the base portion, a second end distant from the base portion and an intermediate portion between the first and second ends. The crupper has a mouth at the second end thereof, the mouth has the form of a channel defining continuous support surface, the channel being formed on a curve turned partially back toward the base. 
     In a feature of that aspect, the curve of the channel is formed on a curl greater than 2(Pi)/3 radians. In another feature, the mouth terminates at a tangentially extending cuff. In a further feature, the channel is at least ⅖ as deep as it is wide. In another feature, the trough portion is downwardly vented. In another feature, the crupper is substantially spoonless. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These aspects and other features of the invention can be understood with the aid of the following illustrations of a number of exemplary, and non-limiting, embodiments of the principles of the invention in which: 
         FIG. 1  shows the general arrangement of a harness on a horse, in side view, including the general positioning of a crupper according to the principles of the present invention; 
         FIG. 2  shows a perspective view of a crupper, with padding, ready for mounting on the horse of  FIG. 1 ; 
         FIG. 3 a    shows a perspective view of the crupper of  FIG. 2 a   , without padding or leather cover taken from above, behind, and to the right; 
         FIG. 3 b    shows a top perspective view of the crupper of  FIG. 3 a    without padding; 
         FIG. 3 c    shows a bottom perspective view of the crupper of  FIG. 3 a    with padding; 
         FIG. 3 d    shows a front perspective view of the crupper of  FIG. 3 a    without padding; 
         FIG. 3 e    shows a rear perspective view of the crupper of  FIG. 3 a    without padding; 
         FIG. 4 a    shows a side perspective view of the crupper of  FIG. 3   a;    
         FIG. 4 b    shows a cross-sectional view taken along the longitudinal centerline of the crupper of  FIG. 3 a   , indicated by section ‘ 4   b - 4   b ’ of  FIG. 3   b.    
         FIG. 5 a    shows a top view of a detail of an embodiment of crupper casting such as that of the crupper of  FIG. 2 ; 
         FIG. 5 b    shows a side view of the crupper casting of  FIG. 5 a   ; and 
         FIG. 5 c    is a rear view of the crupper casting of  FIG. 5 b    on section ‘ 5   c - 5   c’.    
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The description that follows, and the embodiments described therein, are provided by way of illustration of an example, or examples of particular embodiments of the principles of the present invention. These examples are provided for the purposes of explanation, and not of limitation, of those principles and of the invention. In the description, like parts are marked throughout the specification and the drawings with the same respective reference numerals. The drawings are not necessarily to scale and in some instances proportions may have been exaggerated in order more clearly to depict certain features of the invention. 
     By way of a general overview,  FIG. 1  shows a harness  10  for an animal, such as a horse  12 . Harness  10  may include a breast collar  14  that extends about the fore quarters of the horse beneath the base of the neck, a sursingle  16  and crupper assembly  20 . Sursingle  16  extends about the girth of horse  12 , and includes a sursingle belly band  18  that extends beneath the horse&#39;s belly and a sursingle back  22  that extends over the horse&#39;s back. Breast collar  14  is maintained in position relative to sursingle  16  by upper and lower breast collar straps indicated respectively as  24  and  26 . Crupper  20  is mounted to the rear end of horse  12 , and may be maintained in position by a pair of turnback straps  28  that extend from the top of the sursingle, over the hindquarters of the horse, and which connect to the top or upper portion of crupper assembly  20 , as is more fully described below. Turnback straps  28  are adjustable in length, and so govern the longitudinal distance along the back of horse  12  between the top of sursingle  16  and crupper  20 . Lateral position of crupper assembly  20  may tend to be maintained by the use, and suitable adjustment, of upper, lower, and rearward spider straps  30 ,  32 , and  34 . Upper spider strap  30  runs from the top of sursingle back  22  generally rearwardly and diagonally to a node, or ring,  36 . Lower spider strap  32  runs from a D-ring at one end of the center portion of the bottom of sursingle belly hand  18 , generally diagonally upwardly and rearwardly to ring  36 . Rear spider strap  34  runs rearwardly about the contours of the flank of horse  12  to attach to crupper assembly  20 , described below. While right hand straps are visible in the figure, corresponding left hand spiders straps extend on the opposite side of horse  12  such that the forces in the straps relative to the lateral positioning of crupper assembly  20  may tend to the more or less symmetrically balanced and crupper assembly  20  may tend to be maintained in a central position to support the horse&#39;s tail in general longitudinal alignment with the spine of the horse (which, for the purposes of this description lies ideally in a fore-and-aft longitudinal vertical plane). 
     Crupper assembly  20  may include a crupper frame, referred to hereinafter simply as crupper  40 , discussed in greater detail below, padding  42 , and a leather cover  44 . Crupper  40  has a compound concave surface that is fabricated to conform to the compound curvature of a horse&#39;s hindquarters adjacent to the root of the spine. Padding  42  is mounted to sit between the curvature of crupper  40  and the skin of horse  12 . For other animals, a different curvature may be used, such as may correspond to the customary shape of that animal. Leather cover  44  is sewn to padding, the whole assembly of cover and padding fitting over the greater part of crupper  40 . The terminology “crupper” may, depending on context, refer to either the entire assembly, i.e., crupper assembly  20 , or more specifically, to the rigid crupper frame, i.e., designated as crupper  40 , alone. 
     The illustrations provided herein are based on photographic views of an example of a crupper  40 . Crupper  40  may be fabricated from a metal, such as aluminium, but may also be fabricated from other suitable materials. In general, crupper  40  may have a vertical-longitudinal plane of symmetry, allowing for the asymmetries and imperfections in production of castings, and, in particular, of sand castings. 
     Although crupper  40  may be formed as an integral, monolithic casting, crupper  40  can be thought of as having a base, or base portion, or base,  46 , and a trough portion, or trough  48 . In general terms, base portion  46  has a pair of left and right hand pad portions,  50 ,  52  joined by a U-shaped web portion  54 . 
     Pad portions  50  and  52  may each have a contoured inward surface  56 ,  58  that may be formed on a compound concave curvature, that is generally symmetrical about a vertical longitudinal central plane bi-secting trough portion  48 , the two compound curved surfaces tending to lie on the same geometric surface, the curvature being intended to permit crupper  40  to conform, in a general sense to the curvature of the hindquarters of the animal, such as horse  12 , or as the case may be. The compound curvature may be formed according to a geometric polynominal function, or may be formed on radii of curvature about respective vertical and transverse axes, the resultant compound curvature being formed generally to conform to the shape of a horse&#39;s hind quarters. To that end, the transverse radius of curvature may be of the order of 80 to 100 inches, and may be about 90 inches (+/−5″); the vertical radius of curvature may be of the order of 10 to 15 inches, and may be approximately 11½ inches (+/−1 inch). The resultant surface may tend to be an ellipsoid, or a reasonably close approximation of an ellipsoid given the possible imprecision of a sand casting, if such is employed. That is, the surfaces of the two pad portions  50 ,  52  would then be portions lying on the same ellipsoidal surface. Put alternately, the two surfaces may tend to lie on a common torus (i.e., doughnut) surface, where, converting the radii above, the main radius of the torus may be about 75 to 80 inches in the horizontal plane, and the minor radius of the torus may be about 10 to 15 inches. While it is desirable for this curvature to conform closely to the size of the hindquarters of horse  12 , a layer of padding  42  may generally be placed between the surface of the crupper frame pad portions  50 ,  52 , and may tend to take up a reasonable degree of imprecision. 
     In one embodiment, the U-shaped web portion  54  may tend to have quite a square-cornered, or three-sides-of-the-rectangle appearance, with slightly splayed legs. The splay may be about .+−0.2 inch in width over about a 4 inch rise in height, giving a splay angle of about 3 to 4 degrees from either side of vertical for the respective sides, if the back portion is taken as being substantially horizontal in terms of the view shown in  FIG. 3 d   . The back of this web portion  54  is sometimes referred to as the “bridge” between the left and right hand pad portions  50 ,  52 . 
     Each of the pad portions  50 ,  52  may have a lower, rather wider region  68 , that may be smoothly radiused along the laterally outboard portions at its tipper end to give onto an upper, narrowing region or tail, or toe  60  (left or right hand, respectively). At the distal or upper extremity of each tail, or toe  60 , is a strap attachment fitting  62 , such as a rectangular ring, or eye,  64 , whose hinge fitting  66  may be riveted in place. Given that the general use environment may tend to be acidic, mechanical fasteners in the nature of galvanically suitable rivets may be used, such as copper rivets being used in an aluminum casting with stainless steel hinge fittings, for example. The lower lobate regions  68  of pads  50 ,  52  also have mounting fittings  67 , such as may be in the nature of hingedly mounted ring fittings  69  that may be mounted to the laterally outermost extremities of the outer surface  57 ,  59  of the wings (namely lobate regions  68 ) of crupper  40 . Fittings  67  may be employed as connection points for rearward spider straps  34 , whereby the lateral positioning of crupper  40  may be adjusted. In the embodiment shown, and in contrast to the crupper shown in FIG. 4a of U.S. Pat. No. 6,993,892, toe  60  is formed into a less sharp or pointed form, but rather retains a broader, more gently curved form to a relatively higher location such as may tend to increase the upper surface area, and spread, of the crupper, such as may be more comfortable for the animal. In the embodiment shown, the tangent of the uppermost slope portion of the outside edge of the crupper is shown, as alpha 60 . The maximum inward slope angle (taken at the tangent of the point of inflection of the transition, as indicated at alpha 68  forms an intersection angle identified as beta. In the embodiment of U.S. Pat. No. 6,993,892, the corresponding angle is quite pronounced, being less than ¾(Pi) radians, such that toe  60  is relatively long and thin. If the inside edge  71  of toe  60  is taken as a first datum, In U.S. Pat. No. 6,993,892 the intersection at angle beta is located less than halfway from the trough transition (i.e., the height h 71  at which tangent  102  intersects pad portion  50 ,  52 , as may be) to the uppermost tip h 60  toe  60 . By contrast, in the embodiment described herein, that point of intersection lies more than halfway toward datum toe  60 , and may be more than ¾ of the way. Further, the angle of intersection is well more than ¾(Pi) radians and may be more than ⅚(Pi) radians. Expressed differently, toe  60  in U.S. Pat. No. 6,993,892 has a significantly higher aspect-ratio of length to width from the inflexion point to the tip, being roughly 3:1, whereas toe  60  herein has an aspect ratio of less than 3:1, and which may be less than 2:1. As can be seen, the slope at the point of inflexion is also correspondingly shallower. Each of these measures is a proxy for the qualitative difference of the pads being fatter further upward to spread load. 
     The outer surfaces  57 ,  59  of pad portions  50 ,  52  may also be curved, but in such a way that the through thickness t 1  at the extremity of toes  60  may be substantially less than the through thickness t 2  at the lowest extremity of lobate regions  68 . For example, the upper thickness may taper to thickness t 1  of about half an inch, or less. The lower thickness may broaden to thickness t 2  of roughly about an inch (+/−⅛″), and the variation in thickness may be a smoothly continuous increase as a function of position along the arc. This may tend to result in a disproportionate biasing of the weight distribution of the pads toward the lower extremity. 
     Trough portion  48  may include an outboard, or rearward portion  70  that, in use, extends outwardly and upwardly away from the hind quarters of the animal, and an inward portion,  72  that extends inwardly of the surface of the body of revolution on which surfaces  56  and  58  of pad portions  50  and  52  are formed. Rearward portion  70  has the form of a nozzle or chute. Rearward portion may taper from its base (next to the animal) to its distal end. At its broad, proximal end adjacent pad portions  50 ,  52  rearward portion forms a smooth transition into the web, or bridge portion  54  of base portion  46 . At the distal end of rearward portion  70 , the tapered chute region gives onto a third region of trough  48 , the outboard curl or mouth  74  with a downwardly opening arcuate lip  76 . The outboard curl may be considered to commence at the outboard end or margin of apertures  84  noted below. 
     The chute of trough portion  48  has a base, or bottom portion,  78  and side portions  80 , and may include respective inward and outward reliefs  82 , and  84  in the nature of apertures. Apertures  82  and  84  are shown as being generally rectangular or square. Although apertures were provided in the embodiment shown and described in U.S. Pat. No. 6,993,892, for the purpose of making the section lighter, the inventor has observed that the horse&#39;s tail may tend to become warm, and may after time, be a source of discomfort. As horsehair is relatively insulating in a thermal sense, apertures relatively close to the top edge or margin of the trough, as in U.S. Pat. No. 6,993,892, did not apparently tend to promote cooling very well, if at all. To address this issue, trough portion  48  herein is more open than previously, the openings are larger than previously, and the openings are intended to be placed more predominantly below the tail rather than in the former, high up locations that were predominantly beside the tail. It is thought that this arrangement may tend to give better access for cooling air from below to cool the horse&#39;s tail. Trough portion  48  may include a centrally positioned, longitudinally extending external reinforcement rib, or spine,  88 , and may include a transversely oriented, integrally formed rib  90  that may emanate from spine  88  and extend peripherally about thereabout from side to side of trough  48  in a U-shape. Rib  90  may be located at a longitudinal station roughly mid-way intermediate base portion  46  and the point of tangency where the downward curvature  92  of mouth  74  of trough  48  that leads to lip  76 . Rib  90  may be located between inward relief  82 , and outward relief  84 . In the embodiment shown, rib  90  is the only laterally extending structural member between inward portion  72  and mouth portion  74 . The longitudinal width or thickness W 90  of rib  90  is less than either the longitudinal length L 82  of relief  82  or length L 84  of relief  84 . When viewed in bottom view projection, width W 82  of relief  82  may be wider than spine  88 , and may extend lengthwise a distance L 82  more than double W 90 . Similarly, and again as viewed in bottom view projection, as in  FIG. 3 c    the longitudinal extent L 82  of relief  84  is comparable to, or larger than, the longitudinal extent of rib  90 , and the cross-wise projected width W 84  of relief  84  is comparable to or greater than the projected width of spine  88 . As such, more than ⅖ of the projected underside area in trough  48  between inward portion  72  and mouth portion  74  is downwardly open for ventilation, and in the embodiment shown that proportion is greater than ½ of the downwardly projected area in that region, i.e., roughly the total projected area of the region between the left and right hand side portions of trough  48  less the projected area of spine  88  and rib  90 . Expressed differently, the solid portion of spine  88  defines less than of the total projected width of section in the region of either of apertures  82  and  84 . 
     The upper edges or margins of the side portions  80  of the trough portion  48  are indicated as  94  and  96 , and have a profile indicated as  98 . Profile  98  includes an outward end portion  100  and an inward portion  102 . Outward portion  100  is downwardly concave, with local radii of curvature having local centers of curvature lying below trough portion  48 . Inward portion  102  is substantially straight and runs along, and defines the upper edge of, each respective side of trough  48 . In contrast to the previous crupper of U.S. Pat. No. 6,993,892, the inventor has found that a larger curl  110  at mouth  74  may be helpful, such that the horse&#39;s tail may be less likely to rub on a relatively abrupt end edge and thereby irritate the horse. To that end, the outward facing or upper surface  112  of mouth  74  is formed on a large-radius curve alpha 112  extending over more than 120 degrees of arc (i.e., more than ⅔(pi) radians), and having a generally downwardly and forwardly (i.e., with a component of direction toward the horse) extending cuff  114 , which may extend away from curl  110  on a tangent portion  116  at its distal end. In one embodiment alpha  112  may be about 150 degrees. That is, the outer end portion of crupper  40  has a cross-sectional profile that merges into, or is substantially the same as, that of the intermediate portion of trough  48  more generally. However the outer end of the channel or trough is bent around and somewhat back upon itself on a return angle oriented partially back toward the horse. The end of the tail may then be supported on a well radiused large curve, and in the normal condition the tail may tend to hang vertically under gravity somewhat away from cuff  114  rather than swinging against a sharp edge. In the embodiment shown, there are no apertures in curl  110 , such that a continuous, relatively smooth curved surface is presented to the horse&#39;s tail, the curve being both in the lengthwise orientation of crupper  40  (and or the horse&#39;s tail) and in the cross-wise orientation. Furthermore, trough  48  is wide and deep, with an inside depth that is greater than ⅖ of the width, and the width at mouth  74  being more than ¾ the width of trough  48  at the junction with base portion  46 . Thus mouth  74  presents a continuous surface of compound curvature around curl  110 , and provides an out-feed or chute or collar, or cuff on the tangent at its outlet. The lip of curl  110 , at the end of cuff  114 , is also well radiused to be free of sharp edges. 
     The bottom or forward portion or region  78  of the trough portion  48  and  72  may sometimes be referred to as the “spoon” of the crupper. In the earlier apparatus of U.S. Pat. No. 6,993,892 the inner region of the spoon protruded significantly beyond, or inwardly proud of the surface of the body of revolution of the inner surfaces of pad portions  50 ,  52 . The spoon was also angled upwardly and inwardly relative to the slope of the trough taken along the upper, or inside, surface at the trough centerline. This geometry may not have been as comfortable for the horse as might have been desired. In the embodiment shown herein, trough  48  is substantially spoonless. That is, inner portion  78  extends inwardly proud of pad portions  50 ,  52  described herein, but less far than the inward surface of the undeflected cushioning or padding  47 ,  49  on surfaces  56 ,  58 . Expressed differently, the extension distance d 78  inwardly proud of surfaces  56 ,  58  is less than the through thickness t 50  of pad portions  59 ,  52 . Expressed differently again, as a proportion of the width of trough  48  at its inward end, indicated as W 48 , d 78  may be less than about ⅓ of W 48 , may be in the range of ⅙ to ⅓ of W 48 , and in one embodiment may be about ¼ of W 48 . Moreover, in the embodiment the upper surface of inner portion  78  continues on the same, or substantially the same, slope or curvature as trough  48 , rather than having a marked change in curvature, or other distinct deviation upward. That is, in the direction toward the horse it is free up upward slope deviation relative to the inside surface of trough  48  generally, such that no “spoon” shape is formed. 
     Certain geometric relationships between the forgoing elements may be observed. First, as compared to existing cruppers, the center of gravity CG, of crupper  40 , as viewed from the side may tend (a) to be relatively low; and (b) may tend to lie relatively close to the bottom of trough portion  48 , and may tend to lie relatively close to the surface of the body of revolution corresponding to the curvature of pad portions  50  and  52 . 
       FIGS. 5 a , 5 b , and 5 c    are intended to show an alternate form of crupper casting to that described above. Casting  120  is a reduced weight casting, with the same front or rear facing profile, but with generally thinner wall sections. As before, casting  120  may be an aluminum casting. The form and curvature of the trough  122 , and the trough geometry relative to the tail of the horse, as discussed above, is retained, although the wall thickness may be reduced. Casting  120  has a lateral base having two wings  124 , being of left and right hand. As above, casting  120  may be taken as being symmetrical about the longitudinal vertical center-line plane of trough  122 , such that a description of one half also describes the other half, allowing for handedness. 
     In  FIG. 5 c   , the root of the central spine is shown in section as  126 , and the root of the sidewall of the trough is shown in section as  128 . The main vertical post portion is shown as  130  and the lateral outward and downwardly diagonal lobe is shown as  132 . Main vertical post  130  has a rebate, or cut-out, or accommodation  134  of depth corresponding to, or somewhat deeper than, the through thickness of the land of the generally rectangular stainless steel harness mounting hardware, or hinge, to which attachment ring  64  is secured. Similarly, lobe  132  has a rebate, or cut-out, or accommodation  136  for the land of ring  69 . In each case it is intended that the mounting hardware will sit flush with, or shy of, the adjacent surface of casting  120 . The double-dashed lines R 1  and R 2  in  FIG. 5 c    are intended to show the location of radii in casting  120 . Vertical post  130  and lobe  132  are of full thickness, that “full” thickness tapering from a bottom end that is somewhat thicker, to a top end that is somewhat thinner. For example, the bottom edge of lobe  132  may be ⅓ to ⅔ thicker than the top end of post  130 , and in one embodiment may be about ½ thicker. For example, the top through thickness may be about 14 mm, ( 9/16″) whereas the bottom edge may be about 21 mm (⅞″). The taper in thickness may be smooth, i.e., without a step discontinuity. The front face of wing  124  (i.e., the surface facing the horse) may be somewhat hollowed out, or concave, generally to follow the shape of the animal. In the rearward face, there is a portion between the substantially vertically running radius R 1 , to the radius R 2  that runs at about a 4 o&#39;clock angle (or 120 degrees) as seen in  FIG. 5 c   . That portion may be termed flange  140 , and it may be considered to be “stepped” at the radii from the greater thickness to the lesser flange thickness. The front face of flange  140  forms a smooth continuous surface with lobe  132  and post  130 . The rearward face is stepped to a thinner section at radii R 1  and R 2 , that thickness being of the order of between ¼ and ½ of the overall thickness of the adjacent vertical post  130  or lobe  132 , and in one embodiment is about ⅓ of the thickness. For example, whereas the bottom edge of lobe  132  may be 21 mm thick, flange  140  may be 7 mm thick. The projected surface area of flange  140  may be about ⅓-½ of the total projected surface area of wing  124 , and in one embodiment may be about ⅖ of that projected area as seen in the view of  FIG. 5 c   , for example. 
     In the example of  FIGS. 5 a , 5 b  and 5 c   , wing  124  is partially relieved by being thinned at flange  140 , and the relieved portion lies generally upwardly of the lower lobe  132 . Lower lobe  132  retains full thickness, and is correspondingly the region of greatest weight concentration of wing  124 . Also in the embodiment of  FIGS. 5 a , 5 b , and 5 c   , and unlike the embodiment of  FIG. 2 , the through-thickness of the trough portion is substantially uniform, and roughly the same as the through-thickness of the thinned flange portion of wing  124 , allowing for the local variations of thickness in the casting generally. This can be seen in the section of items  126  and  128  in  FIG. 5 c    where the through thickness is comparable to the through-thickness of flange  140 , and substantially less than, and in one embodiment less than half as thick as, the average or mid-height, thickness of main vertical post  130 , and much less than the thickness of pad  132  at its bottom edge. The casting thickness is, of course, greater in the radiused corner portions where the trough and base portions meet. As seen in  FIGS. 5 a  and 5 b   , neither the longitudinal spine nor the lateral mid-trough cross-piece has enhanced thickness, and may be contrasted with the heavier, increased, thickness of spine  88  or rib  90  noted above. 
     Although the embodiments illustrated and described above are preferred, the principles of the present invention are not limited to this specific example which is given by way of illustration. It is possible to make other embodiments that employ the principles of the invention and that fall within its spirit and scope as defined by the following claims.