US3585760A

US3585760A - Portable ski sharpener

Info

Publication number: US3585760A
Application number: US837556A
Authority: US
Inventors: Stanley M Richmond
Original assignee: Individual
Current assignee: Individual
Priority date: 1969-06-30
Filing date: 1969-06-30
Publication date: 1971-06-22
Anticipated expiration: 1988-06-22

Abstract

A power-operated device which utilizes the smooth ski bottom and one edge of the ski as guides for applying an abrasive element to the projecting metal edge at right angles to the bottom surface. No part of the sharpener extends more than a few millimeters past the metal edge to be sharpened so that mountings, screws, plates and cable anchors on the top and sides of the ski do not have to be removed.

Description

United States Patent Inventor Stanley M. Richmond 331 Eugene Medical Center, Eugene, Oreg. 97401 App No. 837,556 Filed June 30, 1969 Patented June 22, 1971 PORTABLE SKI SHARPENER 9 Claims, 4 Drawing Figs.

U.S. CL 51/170 EB, 51/241 S, 144/134 D Int. Cl B241 23/00 FleldotSeareh 51/170, 170.1, 1702,1703, 170.4, 241 S;144/70, 134.5, 137

[5 6] References Cited UNITED STATES PATENTS 2,282,145 5/1942 lndge 51/170.2 3,119,207 1/1964 Nall... 51/170.l

3,159,951 12/1964 Winbauer 5l/170.1 3,412,508 11/1968 Schell, Jr. 51/170 Primary Examiner-William R. Armstrong AnomeyLee R. Schermerhorn PORTABLE SKI SHARPENER BACKGROUND OF THE INVENTION This invention relates to a portable power-operated tool for sharpening skis.

Modern skis are of composite construction from light metals, epoxy resins and fiberglas and most have laminated wooden cores. All of them havelaterally projecting metal edges which have sharp right-angle corners when the skis are new. These corners are formed on edge plates which have a flat sliding surface and a perpendicular side edge surface. This sharp right angle must be maintained for proficiency in skiing.

It is estimated that about two-thirds of all skiing is done on surfaces that are not optimal. The desired powder snow is not ordinarily available. Most skiing is done on packed surfaces and much skiing is done on icy surfaces. Substantially all skiing is done on steep surfaces of varying degree of inclination.

In transversing any slanting surface, the sharp edges of the skis cut into the surface and often the entire weight of the skier is balanced on only 95 or 'A-inch width of the bottom sliding surface of the ski, the balance of the running surface being out in the air. Furthermore, to initiate certain turns and maneuvers, the skier sets his edges. This is a common term in the basics of ski instruction manuals which means to establish a bite or a platform on the terrain from which to shove off or change direction, this maneuver being executed while moving over the terrain at speeds ranging from 5 to 50 m.p.h. When the surface is icy or contaminated with foreign materials, the square corners of the edge plates are subject to considerable wear causing loss of control and requiring frequent sharpenmg.

Heretofore, two different sharpening techniques have been available. The skier may attempt the sharpening operation himself by putting a ski in a vise and manually filing the vertical edge surfaces with a fiat file. The effectiveness of this technique is questionable. It requires a good mechanic and a new sharp file because the edge plates are of a hardness and toughness approaching that of the file. Filing is difficult because of obstructions in the regions that are most in need of sharpening. This is the midlength portion directly under the boot which does most of the work in establishing a bite in skiing maneuvers and is subject to the most wear. It is also in this area that the footplates and bindings usually extend out over the edges of the ski from Ate l inch, ordinarily on both sides of the ski. A filing operation in the hands of most skiers therefore leaves much to be desired.

Established ski shops sharpen skis either with a file or a stationary band sander or bench grinder. The two latter types of machines require 14 feet of linear space to run 7-foot skis through the stationary equipment. Here, again, the footplates and bindings prevent operation of a band sander or bench grinder in the midlength portion of the ski unless the fittings are first removed from the skis. Removal of the fittings, however, is objectionable because of the likelihood that some of the securing screws will not be screwed down firmly enough'in replacement of the footplates and bindings to make watertight connections. Moisture quickly deteriorates the wood laminations used in most skis.

Thus, all methods of ski sharpening heretofore used have required removal of the footplates and fittings at each sharpening in order to do an effective job. As a result of these various difficulties in sharpening skis, at any given time the average pair of skis is in need of sharpening.

Objects of the invention are, therefore, to provide an improved portable power-operated ski sharpener, to provide a ski sharpener which may be used successfully by the average skier without requiring the services of a skilled mechanic, to provide a ski sharpener which does not require removal of footplates and bindings in order to sharpen the midlength portion of the ski, and to provide a device of the type described which is of relatively simple and inexpensive construction and which is convenient to use.

SUMMARY OF THE INVENTION The present device is mounted on a flanged soleplate which is adapted to slide on the fiat bottom surface of a ski turned upside down. It is not necessary to secure the ski in a vise. It may merely be laid across the two chairs. Skill is not required in the use of the device.

All that is necessary is to hold the flange of the soleplate against the edge of the ski to be sharpened and slide thesoleplate along the length of the ski. The abrasive element is motor driven and spring tensioned to hold it against the vertical surface of the edge plate in the proper position to restore the sharp, square corner originally provided by the manufacturer. The parts are positioned and proportioned to clear any projecting parts of footplates and bindings so that these do not have to be removed before sharpening the skis.

With convenient means available for sharpening his skis, the user will keep them in better condition and experience greater pleasure in skiing. The device also provides a safety feature in that properly resharpcned skis will always perform like new equipment, giving the skier a sure-footedness and control that he does not experience with dull-edged skis.

The invention will be better understood and additional objects and advantages will become apparent from the following detailed description of the preferred embodiment illustrated on the accompanying drawing. Various changes may be made in the details of construction and arrangement of parts and certain features may be used without others. All such modifications are included in the invention.

. BRIEF DESCRIPTION OF THE DRAWING FIG. I is a perspective view illustrating the operation of a ski sharpener embodying the principles of the invention;

FIG. 2 is a view on the line 2-2 in FIG. 1;

FIG. 3 is a view on the line 3-3 in FIG. 2 with the footplate omitted; and

FIG. 4 is a view on the line 4-4 in FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENT In FIGS. 1 and 2 the ski 10 is turned upside down in order to present its bottom or running surface 11 uppermost. The ski is equipped with a pair of hard metal edge plates 12, each having a flatbottom surface 13 in the plane of the general bottom surface 11 of the ski and a flat vertical edge surface 14 which projects laterally a small fraction of an inch beyond the vertical edge 15 of the body of the ski. The comer 16 between the bottom surface 13 and edge surface 14 is a angle as formed by the manufacturer.

As explained above, this square corner becomes worn and rounded in use and, if sharpened improperly, the angle may exceed 90. When either of these objectionable conditions occurs, the skis require resharpening to restore the original 90angle between

surfaces

13 and 14. This is necessary in order that the skier may set his edges and establish a bite in the snow or ice surface in changing direction as described above. When corner 16 becomes rounded or if the angle between surfaces 13 and I4 is substantially larger than 90, a dangerous condition exists resulting in loss of control of the skis in executing maneuvers. The function of the present device is to grind off from the surface 14 the minimum amount of metal necessary to restore a square corner at 16 with a right-angle relationship between the

surfaces

13 and 14.

FIG. 2 shows the conventional footplate 17 extending beyond both side edges 15 of the ski. This footplate is omitted in the other views. Many skis also have fastenings for bindings protruding from the side surface 15 although these are not shown on the drawing.

The operation instrumentalities in the present device are mounted on a flat soleplate 20 having a narrow guide flange 21 extending in a straight line along the underside-of the plate as shown in FIG. 4. The width or vertical dimension of flange 21 is only slightly greater than the thickness of edge plate 12 whereby the flange will clear the footplate l7 and any fastenings for bindings on the side surfaces of the body of the ski. Flange 21 is shaped as shown in FIG. 4 to clear the edge plate 12 and engage the side surface 15 closely adjacent edge plate 12.

Mounted in upstanding position on soleplate is a handle 22 whereby the operator may slide the plate 20 along the bottom surface of the ski while holding flange 21 against the side surface 15. The direction of this sliding movement is indicated by double-headed arrow A in FlG. 1. Handle 22 is equipped with a switch 23 and a circuit wire connection 24 for energizing the motor 25.

Motor 25 is pivotally mounted on a vertical post 26 in an overhanging portion of soleplate 20 which projects outward beyond the flange 21. The front end of motor 25 is biased inward in the direction of arrow B by a tension spring 28 which may be adjusted by a thumbscrew 29. The range of this swinging movement is limited by a stop 27 on the motor which will engage an abutment surface 27a on soleplate 20 when the device is not in use. In use, the stop 27 normally remains spaced from abutment 27a as shown in F IG. 3.

Motor shaft 30 is equipped with a drive pulley 31 carrying an abrasive belt 35. Belt 35 is trained around an idler pulley 36 on a pulley shaft 37. Shaft 37 is mounted on one end of an arm 40 which is pivotally mounted on a horizontal pivot 41 on the front end of the motor housing. The belt is tightened by a vertical adjusting screw 42 having threaded engagement with the motor housing and bearing against the underside of the opposite end of arm 40. When a belt 35 is worn out, it may be replaced by loosening the adjusting screw 42 allowing idler shaft 37 to move upward.

The above-described parts are proportioned so that when abrasive belt 35 is tightened in operating condition by adjusting screw 42, the axis of idler shaft 37 will be on the level of edge plate 12 and no higher than the running surface of the edge plate. If desired, the idler shaft 37 may be positioned slightly lower to form an angle of slightly less than 90 between running surface 13 and edge surface 14. This is readily accomplished by mounting the motor 25 slightly closer to soleplate 20. In FIG. 2 the axis of shaft 37 is slightly below the plane of the bottom surface of soleplate 20.

Shaft 37 is horizontal and the length of arm 40 and the position of vertical pivot 26 are such that idler shaft 37 is parallel with the edge surface 14 of edge plate 12 when the abrasive belt 35 on pulley 36 engages the surface 14 in working position. This parallel relationship makes the whole width of the belt effective in working on edge surface 14.

The belt is held in this working position by spring 2% and the pressure exerted by the belt against edge surface 14 is adjustable by thumbscrew 29. As the soleplate 20 is moved along the ski by means of handle 22, the abrasive belt 35 operates on the whole length of one edge plate 12 to sharpen the edge plate. Then by turning the device end for end, the opposite end plate 12 is sharpened in the same manner.

Idler pulley 36 is of very small diameter so as to clear any binding attachments on the side surface 15 of the body of the ski. Thus, the idler pulley 36 will traverse the full length of the ski from end to end with clearance above such attachments and the attachments and footplate 17 do not have to be removed from the ski. A minimal amount of skill is required in the use of the device because it is only necessary to hold soleplate 20 flat against the running surface of the ski and hold flange 21 in engagement with side surface 15 throughout the length of the flange as the device is moved along the ski. When these two requirements are fulfilled, the idler pulley 36 will be positioned on the level of the edge plate 12 and parallel therewith, making it practically impossible to perform a faulty sharpening operation.

Although only the preferred embodiment has been illustrated and described, the invention is capable of various possible modifications. For example, instead of training the abrasive belt 35 around two pulleys, a circular belt or band of shorter length may be mounted on a driven mandrel in position to work on edge surface 14 under the pressure applied by spring 28. Also,-the motor 25 may be equipped wit a short stroke saber saw-type of reciprocating mechanism to reciprocate a flat file against edge surface 14 under the lateral pressure applied by spring 28. Still other modifications of the invention will occur to persons skilled in the art.

Having now described my invention and in what manner the same may be used, what I claim as new and desire to protect by Letters Patent is:

A portable ski sharpener for a ski having metal edge plates on its bottom surface, said sharpener comprising a soleplate adapted to slide on said bottom surface of the ski, guide means on said soleplate arranged to engage a side edge of the ski, a handle on said soleplate for sliding the sharpener along said bottom surface of the ski, a motor-driven sharpening device comprising an abrasive band having a working movement approximately perpendicular to said soleplate, means mounted said device for transverse movement on said soleplate outwardly from said guide means, and spring means tensioning said sharpening device inwardly toward said edge plate to engage the edge thereof when the sharpener is in working position on said ski.

2. A ski sharpener as defined in claim 1, said guide means comprising a flange on said soleplate.

3. A ski sharpener as defined in claim 2, said flange being shaped to clear said edge plate and engage a portion of the side edge of the ski adjacent said edge plate.

4. A ski sharpener as defined in claim 1, said band comprising a belt mounted on a drive pulley and an idler pulley.

5. A ski sharpener as defined in claim 4, said idler pulley having an axis parallel with said soleplate and adjacent the plane of the ski-engaging surface of said soleplate.

6. A ski sharpener as defined in claim 5, said spring-tensioning means causing said idler pulley to press said abrasive belt against said edge of said edge plate.

7. A ski sharpener as defined in claim 1, said mounting means comprising a pivot on said soleplate.

8. A ski sharpener as defined in claim 7, said pivot being positioned on said soleplate outwardly from said guide means.

9. A portable ski sharpener for a ski having metal edge plates on its bottom surface, said sharpener comprising a soleplate adapted to slide on said bottom surface of the ski, a guide flange on said soleplate arranged to engage a side edge of the ski, a handle on said soleplate for sliding the sharpener along said bottom surface of the ski, perpendicular pivot on said soleplate, a motor mounted for pivotal movement on said pivot, a drive pulley on said motor, an idler pulley mounted on said motor in a position adjacent one of said edge plates when the sharpener is in working position on said ski, an abrasive belt on said pulleys, and spring means acting on said motor to press said belt against the edge of said edge plate.

Claims

1. A portable ski sharpener for a ski having metal edge plates on its bottom surface, said sharpener comprising a soleplate adapted to slide on said bottom surface of the ski, guide means on said soleplate arranged to engage a side edge of the ski, a handle on said soleplate for sliding the sharpener along said bottom surface of the ski, a motor-driven sharpening device comprising an abrasive band having a working movement approximately perpendicular to said soleplate, means mounted said device for transverse movement on said soleplate outwardly from said guide means, and spring means tensioning said sharpening device inwardly toward said edge plate to engage the edge thereof when the sharpener is in working position on said ski.