Keel for snowmobile front skis
Mabie et United States Patent KEEL FOR SNOWMOBILE FRONT SKIS [76] Inventors: Norman H. Mabie, 38 Fremont Sq.; John P. Putnam, 4 Rase Ave., both of Claremont, NH. 03743 [22] Filed: Sept. 4, 1973 [21] Appl. No.: 393,726  
 [52] US. Cl 280/28; 180/5 R [51] Int. Cl B62b 19/00 [58] Field of Search 280/28; 180/5 R [56] References Cited UNITED STATES PATENTS 488,266 12/1892 Jordan 280/28 3,593,814 7/1971 Bauler 180/5 R 3,632,126 l/l972 Shorrock 280/28 3,709,512 l/l973 Albertson 180/5 R X 3,778,074 12/1973 Kozlow 280/28 Primary ExaminerDavid Schonberg Assistant Examiner-Michael J. Forman Attorney, Agent, or Firm-Pearson &amp; Pearson [57] ABSTRACT A keel for use on the front skis of snowmobiles, comprising a series of relatively short, angularly configured multi-edged blades independently and replaceably mounted in a single, one piece, grooved backing extending along the keel in selected, spaced relationship and means for independent indexing of the blades from one edge to another or for individual replacement or removal by use of a simple tool and without removing other blades from the keel. Each blade is laterally supported by an individual clamp held by an individual screw so as to be replaceable without moving other blades, clamps or screws.  
 6 Claims, 14 Drawing Figures KEEL FOR SNOWMOBILE FRONT SKIS BACKGROUND OF THE INVENTION This invention relates to an improvement in ski keels, particularly those used for snowmobiles. Snowmobiles tend to side slip badly when cornering at moderate to high speeds. The severity of the problem depends on speed and the ice or snow conditions. In any case, it has been desirable to use keels on snowmobile skis and, indeed, some skis are particularly designed to accommodate such keels as disclosed in U.S. Pat&#39;. No. 3,632,126 to Shorrock and U.S. Pat. No. 3,605,926 to Leonawicz. Similar keel-like devices have been used on sleigh runners, as in U.S. Pat. No. 1,957,372 to Thompson, and on ice racers, as in U.S. Pat. No. 3,047,303 to Pliska.  
  In a somewhat different art, removable skate runners have been disclosed in U.S. Pat. No. 2,988,369 to Rebicek, and such runners may have a plurality of cutting edges, some held in the body of a blade holder while others are positioned in an ice-contacting position.  
  In recent years, the advent of serious snowmobile racing, for example that sponsored and encouraged by the United States Snowmobile Association, has stimulated a considerable amount of interest in improving snowmobile performance characteristics and one feature of snowmobile racing is particularly unique-the fact that changing temperature or weather conditions can change the kind of ski keel that is optimum and also change the rate of wear on a keel. I-Ieretofore, no keel system has existed which is sufficient to meet the challenge presented by these circumstances.  
 SUMMARY OF THE INVENTION Therefore, it is an object of the invention to provide an improved keel for use in conjunction with snowmobile skis, in which the cutting contact area can be quickly modified to suit conditions.  
  Another object of the invention is to provide a keel easily adapted to a variety of snow, ice and temperature conditions by means of quick change clamping means.  
  Still another object of the invention is to provide a keel carrying a plurality of blade edges which can be removed independently.  
  Another object of the invention is to provide a keel that carries within it blade members having a plurality of edges which can be advanced to operable position independently with a simple tool, such as a hexagonal wrench, a screwdriver, or the like.  
  Other objects of the invention will be obvious to those skilled in the art on reading the instant application.  
  The above objects have been substantially accomplished by construction of a keel assembly consisting of a one-piece backing member having an elongate channel into which, and from which, blade members can be independently mounted and removed to provide whatever keel action is required for particular conditions. A particular advantage of the invention is that it enables the quick removal or renewal of blades and provides means to store multi-edged blade members without undue wear thereof.  
 ILLUSTRATIVE EMBODIMENT OF THE INVENTION In this application and accompanying drawings, there is shown and described a preferred embodiment of the invention and suggested various alternatives and modifications thereof, but it is to be understood that these are not intended to be exhaustive and that other changes and modifications can be made within the scope of the invention. These suggestions are selected and included for purposes of illustration in order that others skilled in the art will more fully understand the invention and the principles thereof and will be able to modify it in a variety of forms, each as may be best suited in the condition of a particular case.  
 IN THE DRAWINGS FIG. 1 is a perspective view, from the bottom, of a keel assembly of the invention.  
  FIG. 2 is a section of an alternative construction to that shown in FIG. 3.  
  FIG. 3 is a section of the keel taken along Line 3-3 of FIG. 1.  
  FIG. 4 is a fragmentary plan view of the keel shown in FIG. 1.  
  FIG. 5 is a fragmentary elevation of the keel shown in FIG. 1.  
 FIGS. 6 and 7 show a two-edged blade member.  
 FIGS. 8 through 11 show alternate blade designs.  
  FIGS. 12 through 14 show three alternative means for holding multi-edged blade members.  
  FIGS. 1 through 4 and 5 illustrate a skimobile keel 10 comprising bolt means 11 to fasten the keel onto a front ski of a snowmobile. In FIG. I, most of the individual blade members are removed for clarity. Carbide cutting blade member 14, however, are shown as platelike and angularly configured with straight sharp edges and smooth, flat, planar side faces. Each blade is immovably seated in a groove 16 in an elongated one piece, blade seating, or backing member 12. A predetermined number of blades 14 are seated in groove, or channel, 16 with a cutting edge 15 thereof exposed for cutting into and gripping ice. The individual blade members 14 are retained by an equal predetermined number of clamps, or clamp jaws, 18 and the clamps are retained by an equal predetermined number of screws 20, each screw fastening a single clamp against a single blade against the opposite wall of the groove, to tighten or loosen the same. The elongated blade seat member, or backing I2 is of one piece and single machined steel construction, excepting that one wall portion 21 is alternately formed of spaced recesses 17 for seating the aforesaid clamps l8 and spaced, integral bosses, or portions, 22 of the machined steel wall 21 of backing 12. As shown in the drawing, the individual blade inserts l4 and individual clamps 18 are relatively short, with one clamp and/or screw operably associated with each blade insert so that other blades, clamps or screws are not effected in replacing or turning a blade.  
  Although it does not show in the drawing, the keel is normally bent slightly to form a slight are as is known in skimobile keel construction. The clamps 18 are usually aligned along the outside, i.e. the larger circumferential edge of such a keel.  
  FIG. 3 shows how a clamp 18 is pulled against a blade member 14 by screw 20. Note that the elongate steel backing, or seat member, 12 includes two grooves 28 at the bottom of channel, or groove, 16 along a raised foot member 30. This arrangement allows the stored&#34; cutting edge 32 of blade member 14 to be maintained free of any possible abrading contact with the inner walls of groove 16 in seat member 12, and yet to be firmly supported by foot 30. The use of two grooves 28 in the construction is particularly useful in that it allows the reversal of the blade 14 to face either side of the channel. Note also that clamp 18 includes an integral, raised, bearing ridge 34 which, in combination with recess 36, facilitates the tightening of clamps 18 against blades 14 by screws 20.  
  FIG. 2 illustrates a similar construction, except that the clamping action is effected entirely by a screw (at 38, but not shown) which goes through both the unitary grooved seat member 40 and the blade member 42.  
  FIGS. 6 and 7 show more detail of a two-edged blade member 14. The edges will normally have a 30-degree relief on cutting edges 44.  
  FIGS. 8 through 11 show other blade members 46, 47, 48 and 49 adapted for use with the seating member shown in FIG. 3. The blades may be rotated to a fresh edge when so desired by simply loosening the screw fastener and turning the blade to a new cutting edge. All edges of the illustrated blades are usually bevelled at about 30 to 60; although, in some snow conditions, they could advantageously be flat. i.e. have no bevel.  
  FIGS. 12, 13 and 14 show various other means of holding replaceable blade members 14.,However, each of these embodiments of the invention has a particular disadvantage avoided by using the favored constructions used in FIGS. 1 through 5. For exampple, bladeseating member 60 lacks the blade-protecting shoulder-and-groove arrangement of FIGS. 2 and 3. Bladeseating members 70 and 80, shown in FIGS. 13 and 14 respectively. lack the preferred use of a channel to give bilateral support to the blade members along the entire length thereof.  
  It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described and all statements of the scope of the invention which might be said to fall therebetween.  
 We claim:  
 1. A keel assembly comprising:  
 an elongated, one-piece backing member having an elongated groove, or channel, with smooth, flat planar side walls and a bottom wall;  
 a predetermined number of relatively short blade members, spaced along said groove, each having smooth flat, planar side faces in contact with the side walls of said groove;  
 an equal predetermined number of relatively short clamp members, spaced along said groove, each operably associated with one of said blade members for clamping said blade member in said groove and providing lateral support thereto and an equal predetermined number of individual fasten ing means, each for reversibly tightening and loosening each said clamp member against its blade member,  
 any one of said blade members being individually re movable without removing the other blade member in said groove by loosening only the said fastening means holding the clamp member thereof.  
 2. A keel assembly as defined in claim 1 wherein:  
 said elongated, one-piece, grooved backing member is of arcuate configuration and one said side wall thereof includes an equal predetermined number of spaced recesses, and integralbosses, each said recess seated one of said clamp members.  
 3. A keel assembly as defined in claim 1, wherein:  
 each said blade member is of angular configuration, includes a plurality of straight sharp edges; and  
 each said fastening meansis a screw passing through a blade member for independently turning each;  
  said blade member to, expose one of said straight edges of said blade member. 4. A keel assembly as defined in claim 1, wherein; the said bottom wall of said channel includes a foot member extending longitudinally therealong for supporting said blades and at least one recess providing a compartment for holding an unused edge of said blades. 5. A keel assembly as defined in claim 1, wherein: said elongated, one-piece backing member comprises a small arc therein; and said short clamp members are mounted on the said one piece, backing member. 6. In a keel for the front skis of a snowmobile of the type having a grooved backing of predetermined length with a pair of opposite side walls and a plurality of carbide cutting blade inserts seated in end-to-end relationship with said groove, the combination of:  
 a single, one-piece, machined steel backing; fastening means for permitting easy, rapid removal,  
 replacement, respacing or turning of each individ:  
 ual said insert without removing other inserts in said groove, said means comprising:  
 alternate, integral, spaced bosses and recesses extending along one side wall of said backing alongside said groove;  
 a plurality of relatively short blade inserts;  
 a plurality of clamping jaw members, each received in one of said recesses; and  
 each adapted to clamp one of said blade members against the other wall of said groove;  
 a plurality of screws, each in one of said clamping jaw members and threaded in said backing;  
 each said clamping jaw member clampingone of said inserts in immovable position in said groove, but permitting movement, or removal, of said insert when the screw in said member is loosened without requiring removal of other blade inserts of said 1 keel.