United States Patent 3837123

A tool for sharpening metal edges, particularly running edges on snow skis, in which a hand held housing supports pairs of abrading wheels rotatably mounted on parallel axes spaced in such a manner that the wheel peripheries overlappingly intersect at substantially right angles and thereby tangently engage right angularly related surfaces forming the ski's running edge when the tool is operatively positioned for guided movement longitudinally over the ski bottom.

Application Number:
Publication Date:
Filing Date:
Primary Class:
Other Classes:
76/88, 451/358, 451/549, 451/555
International Classes:
A63C11/06; B24D15/06; (IPC1-7): B24D5/00; B24D7/00
Field of Search:
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US Patent References:

Foreign References:
Primary Examiner:
Jones Jr., James L.
It is claimed

1. A hand tool for sharpening metallic edge members marginally bordering the bottom running surface of a snow ski and having a pair of intersecting surfaces to be sharpened comprising in combination: a manually engageable hollow body formed to fit the palm of an operator's hand and having a portion providing planar guide means adapted to slidingly engage the bottom running surface of the ski and to stabilize the tool in operating movements thereof longitudinally over said running surface, a pair of parallel spaced shafts mounted across an open sided chamber in said body, the axes of which parallel said edge member in the tool's operating position thereover and are so arranged that one lies coincident with the plane of said guide means and the other does not; at least one abrasive wheel mounted on each of said shafts such that the respective peripheries thereof are axially spaced and overlappingly intersect to provide tangential engagement of each wheel's periphery with one of the intersecting surfaces of said edge member, whereby to and fro sliding motion of the tool longitudinally along said edge member causes the peripheral engagement of said wheels with said surfaces to form a sharp snow engaging edge at the intersection thereof.

2. The invention of claim 1 wherein said wheels are rotatably adjustable to present multiple unworn abrading areas of their peripheries to the said intersecting surfaces to be sharpened.

3. The invention of claim 1 wherein at least two abrasive wheels are mounted in axially spaced relation on each of said shafts to cooperate with said guide means for laterally stabilizing the tool in operation.

4. The invention of claim 1 wherein said intersecting surfaces of the edge member are right angularly related, and each said shaft parallels one of said surfaces and is geometrically spaced therefrom such that tangential engagement of said peripheries with said surfaces occurs substantially at the line of intersection of the latter.

5. The invention of claim 1 wherein said body comprises a unitary open bottom hollow member having an elongated upper wall portion, a curvilinear upper wall portion subtending from one end of said elongated wall portion, and a pair of laterally spaced side walls transverse to said upper wall portions, the wall portions and walls being formed to fit the palm of an operator's hand; said guide means being located at the other end of said elongated wall portion and comprising a planar surface adapted to operatively engage the bottom planar running surface of the ski, with the axes of said shafts being aligned, one parallel over and the other substantially in, the plane of said running surface, laterally beyond the edge member.


This invention relates generally to sharpening tools and more particularly to hand-operated tools for sharpening and abrading metallic running edges of snow skis and the like.

Presently known devices for sharpening metal edges on skis generally employ one or more multiple edge cutting bits adapted to engage one surface of the ski edge. Such multiple edge bits are normally mounted in a hand held housing, and the operator presses the cutting bits into the metal ski edge, pushing the same therealong to remove a series of small metal shavings. This serves to sharpen one edge surface, usually the outer edge surface thereof bordering the lateral sides of the ski. In still other areas, unrelated to ski edges, sharpening tools using rotatably driven abrasive wheels provide a narrow V-shaped slot within which a knife blade, for example, may be drawn back and forth across the rotating wheels to effect sharpening therof. The cutting edge thus formed has an extremely acute cutting angle which is desirable for such cutting instruments. In properly sharpening a ski edge, however, the running or cutting edge thereof is formed at the intersection of two right angularly related surfaces, one parallel to the ski bottom and the other at right angles thereto along one side of the ski. It is desirable to sharpen both surfaces to provide a proper snow engaging edge.

So far as I am aware, the present state of the art has failed to provide a hand tool for sharpening the metal edges of a snow ski in the above-described desirable manner, or that is simultaneously over both right angularly related surfaces providing the cutting edge thereof. The present invention is directed to the solution of this problem and the provision of an effective hand operated tool for providing the desired sharpening function. In brief, this invention employs a plurality of cylindrical abrasive wheels mounted on parallel shafts, the rotational centers of which are spaced to provide a right angular relationship between the overlapping intersecting peripheries of adjacent abrasive wheels. The ski edge is sharpened by moving the sharpening tool along the length of the ski, guiding the tool on the running surface of the ski bottom. As a result both surfaces of the metal edge are simultaneously abraded or, that is, both the snow engaging bottom and side surfaces thereof, to effect a sharp snow biting or cutting edge; the abraded surfaces being characterized by a slightly hollow ground formation.

One of the more important objects of this invention is to provide a simple, easy to operate hand tool for sharpening metal edges on snow skis.

Another object of this invention is to provide a ski edge sharpener or tool utilizing a plurality of rotatable abrasive wheels arranged to effect a hollow ground formation of intersecting surfaces forming the snow engaging edge to be sharpened.

An additional object is to provide a ski edge sharpener as aforesaid provided with easily adjustable means for presenting multiple abrading surfaces for sharpening the ski edge.

A further object of this invention is to provide a hand tool for sharpening ski edges which includes means for positively guiding the tool in a manner to insure sharpening of the ski edges simultaneously in planes substantially coincident with the plane of the ski bottom and at right angles thereto.

Still another important object of this invention is to provide a tool for sharpening ski edges which is compact, light in weight and may be easily transported in a jacket pocket or the like.

Having thus described the present invention, the best mode presently contempleted so as to enable those skilled in this art to understand and practice the same will be described in association with a presently preferred embodiment thereof illustrated in the accompanying drawings.


FIG. 1 is a cross-sectional view of the sharpening tool according to this invention operatively associated with a ski and illustrating the working components thereof;

FIG. 2 is a bottom plan view thereof;

FIG. 3 is a skematic diagram illustrating the geometrical relationship of the abrasive wheel elements thereof; and

FIG. 4 is a perspective view illustrating the sharpening tool operationally positioned for sharpening a metal running edge of a snow ski.


Turning now to the details of the particular embodiment of this invention illsutrated in the drawings, initial reference is made to FIGS. 1, 2 and 4, showing a sharpening tool 10 according to this invention as comprising a unitary housing 11 formed to fit in the palm of an operator's hand so as to be grasped between the thumb and extended fingers. The housing includes an elongated wall portion 12 of substantially wedge-shaped cross-section, as shown in FIG. 1, which may be suitably grooved (not shown) on its outer surface to provide gripping surfaces for the individual fingers of the operator. Such elongated wall portion 12 merges into a rearwardly and downwardly extending top wall portion 13 of generally curvilinear profile; portions 12 and 13 presenting a unified wall of substantially rectangular plan, as illustrated best in FIG. 2. The outermost end of the elongated wedge sectioned wall portion 12 is formed to provide a planar guide surface 14 adapted to engage the planar bottom wall or running surface of the ski 15 for the purpose of buiding the tool 10 along the length of the ski in operation, as will be described in greater detail hereinafter.

The body 11 also is formed with a substantially open bottom side to enclose a hollow chamber 16 enclosed on 3 sides by the wall portions 12 and 13 and two laterally spaced side walls 17 17 (see FIG. 2). In practice it is contemplated that the body 11 may best be cast light weight metal such as aluminum, or molded rigid plastic.

As will best be understood from FIG. 2, the body 11 forms a protective cover for pairs of laterally spaced cylindrical abrasive wheels 18 and 19 mounted on parallel spaced axle shafts 20 and 21, respectively, which extend transversely between the two side walls 17, 17 and pass through opposite aligned openings 22 therein. The axle shafts 20 and 21 may be retained in their mounted position between the side walls of the housing by any suitable means, such as riveting over the outer ends thereof, in the manner illustrated.

The pairs of abrasive wheels 18 and 19 are rotatably mounted on the axle shafts such that wheels 18, 18 are disposed immediately adjacent the inside surfaces of side walls 17, 17 on shaft 20, while the pair of wheels 19, 19 are mounted on shaft 21, adjacent wall portion 13, in between the abrasive wheels 18, 18 where they are held in spaced parallel relationship by means of intervening cylindrical spacer 24. It is fully contemplated that whereas two wheels 19, 19 have been illustrated, the same may comprise a single elongated abrasive cylinder in which event the necessity for the space means 24 will be eliminated.

As best shown in the FIGS. 1 and 2, the peripheries of the wheel sets or pairs 18 and 19 overlap and intersect according to a predetermined geometric relationship as best illustrated in FIG. 3 of the drawings. With reference to the latter figure, it will be recognized that the center of shaft 21 is located to lie along an X coordinate axis, at a distance from the intersection of the X and Y coordinates equal to one-half the diameter of an abrasive wheel 19. In a similar fashion the axis of shaft 20 lies along the Y axis a distance equal to one-half the diameter of an abrasive wheel 18. In this preferred embodiment illustrated it will be appreciated that the diameter of the wheels 18 and 19 are substantially equal although this is not essential to the successful operation of the present invention so long as the geometric relationship of the wheels to provide their overlapping intersecting alignment, as illustrated in FIG. 3, is maintained. To that end it will be understood that a right angle 26 is formed by the tangents of the intersecting wheels regardless of their diameters and it is this relationship that is required to successfully carry out the present invention.

With the foregoing relationship in mind, it will be understood, with reference to FIGS. 1 and 4 in particular, that the tool 10 is positioned on the ski 15 so that the guide surface 14 of the housing engages the bottom running surface of the ski while the curved housing wall portion 13 subtends along one side edge thereof. So positioned the peripheries of abrasive wheels 18 and 19 engage the right angularly related intersecting surfaces forming the cutting or snow engaging outer edge of the metal edge member 30 which familiarly comprises an elongated metal bar or strip either unitary or in sections, inset into the ski bottom along the lateral margins of the snow engaging or running bottom surface of the ski. In the inverted position of the ski, or that is with its bottom running surface up, as illustrated in FIG. 4, the two shafts 20 and 21 lie above and in the plane of the guide surface, respectively, while the wheels 18 rest on the top surface 31 of the edge member 30 and wheels 19 oppose the exposed outer edge surface 32 thereof in a normal rest position for the tool. By applying pressure to the tool housing 11, substantially in the direction of he arrow P shown in FIG. 1, the resultant forces imposed on the axles 20, 21 and thus the abrasive wheels 18 and 19, cause the latter to abradingly engage the outer surfaces 31 and 32 of the edge strip 30, substantially at their line of intersection as diagrammed in FIG. 3.

To operate the tool, the operator reciprocates the same with a to and fro motion gradually working along the length of member 30 while pressing the same toward the corner of the ski edge. This action simultaneously abrades both surfaces 31 and 32 of the metal member 30 producing an extremely sharp snow engaging corner or cutting edge which is characterized by slightly hollow ground surfaces 31 and 32 in accordance with the contour of the abrading wheels 18 and 19.

As the portions of the wheels engaged with the metal edge member gradually clog with metal particles, each wheel may be rotated slightly from time to time to provide new abrading surfaces. Also wheels of different abrading grit may be used as by using two tools 10, or alternate wheels of different abrasive grit to effect rough and finish grind finishes to the sharpened surfaces, if desired.

It further will be recognized that by virtue of the inter-engagement of the guide surface 14 and the plane of the ski bottom running surface, the tool 10 is guided to maintain the abrasive wheels in their tangential engagement with the right angular intersecting surfaces of the ski edge. Further due to the lateral or spaced relationship of abrasive wheels 18, 18 in particular, as well as the length of guide surface 14 on the housing, the tool exhibits good lateral stability in operation preventing tipping or tilting thereof during the to and fro sharpening motion.

From the foregoing it is believed that those familiar with this art will readily understand and appreciate the novel aspects and utility of the present inventive combination which obviously are susceptible to modification and substitution of equivalents within the skill of this art. Therefore, having described the particular embodiment of this invention illustrated in the accompanying drawing so as to enable those familiar with the art to understand and practice the same,