US3894744A

US3894744A - Protective edge for skis

Info

Publication number: US3894744A
Application number: US501361A
Authority: US
Inventors: Wolfgang Benner
Original assignee: Individual
Current assignee: Individual
Priority date: 1973-08-30
Filing date: 1974-08-28
Publication date: 1975-07-15
Anticipated expiration: 1992-07-15
Also published as: DE2343725A1

Abstract

A protective edge profile for skis of cast plastic material having a horizontal leg portion aligned with the running surface and a vertical leg portion embedded in the ski body so that it can slide longitudinally in relation to the ski body, without being separable therefrom. In the shovel portion of the ski body, the edge profile is also longitudinally anchored through recesses in its vertical leg portion.

Description

United States Patent 1191 Benner [45] July 15, 1975 [54] PROTECTIVE EDGE FOR SKIS FOREIGN PATENTS OR APPLICATIONS [761 lnvemorl woligfi'ng Benn", 1,428.988 1/1969 Germany 280/1113 N Landsledlerstrasse. 8 K r h g, 62.069 2/1940 Norway U 280/1 1113 v .lagst, Germany [50,035 l2/193l Switzerland 1 1 280/1113 N 165,866 2/l934 Switzerland .i 280/] 1113 N [22] Flled- 281 1974 172,404 12/1934 Switzerland 280/1 1.13 N [2 Appl 501 3 l87,l45 l/l937 Switzerland 11 280/1 [.13 N

- Primary ExaminerDavid Schonberg [30] Fol-Hg" Apphcatlo" Data Assistant Examiner-Milton L. Smith Aug. 30, I973 Germany 2343725 Armrney, Agent, or Firm-Bacon & Thomas [52] U.S. Cl 280/1113 E [57] ABSTRACT [51] Int. Cl. A63c 5/04 I [58] Field of Search 280/1113 E. 1 113 J [L13 N protectlve edge profile for SklS'Of cast p astlc mate- 280 L13 P [H3 v H '3 Q H U F rial havmg a honzontal leg port1on ahgned w1th the I L13 1 H3 i 13 13 running surface and a vertical leg portion embedded i in the ski body so that it can slide longitudinally in relation to the ski bod without bein se arable there- [56] References Clted p from. In the shovel portlon of the Ski body, the edge UNITED STATES PATENTS profile is also longitudinally anchored through reces ses in its vertical leg portion. 2.918.293 lZ/l959 Tavi 280/1 l.l3 F 3.198.535 8/1965 Brown, Jr .1 280/1 1.13 E 10 Claims, 9 Drawing Figures PROTECTIVE EDGE FOR SKIS BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to protective edges for skis made of plastic material, and in particular to protective edges for skis made of foamed plastic, the protective edge being an angled metal profile of which one leg portion serves as an anchoring member.

2. Description of the Prior Art It has become common practice to protect the edge portions of the running surface of a ski, and in some cases also of the upper surface of the ski, with an abrasion resistant metal profile, known as a steel edge. Such a protective edge gives the ski improved guide characteristics, while preventing premature wear of the ski body itself. In order to minimize the resultant change in overall elasticity of the ski body, prior art steel edges had to be applied in the form of short longitudinal sections, or lamellas, of a flat steel profile, the sections being attached to the ski body by means of screws in a longitudinally adjoining arrangement.

Also known from the prior art are protective edges in the form of angle profiles which are received in a milled recess in the ski body, the horizontal leg of the profile being screwed to the body in flush alignment therewith. From this horizontal leg portion extends a heavy vertical leg portion, the latter representing the visible portion of the steel edge. This downwardly extending vertical leg portion has a height which corresponds to the thickness of a special running sole attached to the underside of the ski body.

All-plastic skis, for instance skis made of foamed polyurethane, or polystyrene hard form with highdensity outer zones, have, by their very nature, excellent sliding characteristics, so that an additional special running sole is not necessary and the mounting of the above-mentioned known protective angle profile would involve unnecessarily high production cost.

It is further known to provide protective edge profiles of metal which are embedded inside plastic profiles, length sections of which are then glued onto corresponding recesses in the ski body. Such a combination between a metallic edge profile with plastic material brings with it the problem of undesirable warping of the sections due to their different coefficients of thermal expansion. ln all these cases, furthermore, there remains the basic problem of the inability of exactly controlling the increase in rigidity of the ski body, as soon as a metallic protective edge profile is added to it.

SUMMARY OF THE INVENTION Underlying the present invention is the objective of providing a metal protective edge for a ski, especially a ski of foamed plastic material, where the protective edge cooperates in such a way with the ski body that the assembly operation is greatly simplified and, furthermore, that the initially determined optimal resiliency characteristics of the ski body are not impaired, and lastly, that no twisting of the ski body results from the combination.

The present invention proposes to attain the above objective by suggesting the combination of an angled protective edge profile with a ski body of the earliermentioned type, the protective edge profile having a laterally overhanging profile portion on the upper edge of its vertical leg which, due to recesses or cuts provided therein, is longitudinally fixedly connected with the shovel portion of the ski body at the front end thereof, and which represents a continuous, smooth profile for the remaining length of the ski body, so that the unattached portion of the received leg of the edge profile is slidable longitudinally in relation to the ski body, under differing longitudinal expansion responses and deflection.

The aforementioned features afford a very simple anchoring of the protective edge in the ski body, permitting assembly by simply placing the edge profile into the mold for the ski body, no machining or other work being necessary on the protective edge, after the ski body is molded. Since during curing and cooling of the plastic material the ski body itself shrinks to a much greater extent than the longitudinal contraction taking place at the protective edge itself, one may design the assembly process in such a way that the protective edge protrudes from the rear end of the finished ski body, due to the aforementioned unequal longitudinal contraction. The protruding part of the protective edge is then simply ground off. The shrinkage of the foam plastic material brings with it, during the curing process, a certain relative displacement between the plastic material and the metallic edge profile, so that the finished ski body holds the protective edge by the anchoring edge portion of its vertical leg in a correspondingly shaped groove, while permitting longitudinal displacement therebetween.

Since no particular resiliency requirements are made of the shovel portion of the ski body, the longitudinal attachment of the protective edge is conveniently arranged in that length portion of the ski body. This longitudinal attachment is preferably obtained in such a way that the length portion of the vertical leg of the protective edge profile which is placed in the shovel portion of the ski body is provided with recesses or cuts into which the plastic material of the ski body penetrates, thereby establishing a firm connection. These recesses in the protective edge within the shovel portion also limit the stiffening effect of the protective edge in that portion of the ski body, which otherwise would be undesireably stiffened, thereby increasing the risk of fracture in this especially vulnerable portion of the ski body.

In order to insure movability of the enclosed profile leg in that portion of the ski body inside which such mobility is desired, the protective edge profile is preferably coated with a suitable anti-friction coating material, before being surrounded by plastic material during the casting process. In this manner, a clean separation between the metal of the profile and the surrounding plastic material is obtained so that the protective edge is essentially retained only by the undercut crosssectional portions of its vertical leg outline, to the extent that it is not also longitudinally retained in the shovel portion of the ski body.

In the shovel portion of the ski body, where the protective profile is longitudinally retained, by virtue of a series of cuts or recesses provided therein, these cuts may either be in the form of a series of transverse bores in the web portion of the vertical leg, or they may also reach through the upper edge portion of the vertical leg, in which case a protective edge profile is much more flexible.

The material used for the proposed protective edge profile is preferably steel, the latter permitting positioning of the prepared profile inside the ski body mold by means of magnets. However, it is also possible to use protective edge profiles of other suitably hard and flexible metals, such as aluminum, or stainless steel.

Where it is desirable to further increase the resistance of the ski body against breakage, especially in its shovel portion, a similar edge profile may be embedded along the upper edges of the ski body, the upper edge profiles serving as countervailing tension elements. The protective edge of the invention is preferably designed as a simple rolled or drawn metal profile, the cuts or recesses being produced in a die cutting operation. In the case of a very flexible edge profile, in which the recesses reach through the entire height of the vertical leg portion, the flexibility obtained thereby permits convenient positioning of the prepared edge profile in the casting mold, pre-bending being necessary only in the transverse direction.

The present invention is not intended to be limited to the production of a protective edge profile alone; rather, it should be seen as encompassing a ski body incorporating such a profile, as well as the novel method of combining a ski body of plastic material with two or more protective edge profiles of the type suggested herein.

BRIEF DESCRIPTION OF THE DRAWING Further special features and advantages of the invention will become apparent from the description following below, when taken together with the accompanying drawing which illustrates, by way of example, several embodiments of the invention, represented in the various figures as follows:

FIG. 1 shows, in a somewhat schematic representation, a ski body with a protective edge profile incorporated therein, as an embodiment of the invention;

FIG. 2 shows, in an enlarged transverse cross section, an edge portion of the ski body of FIG. I, with the protective edge profile in cross section;

FIGS. 3-9 are similar to FIG. 2, showing seven alternative embodiments of the protective edge profile, as suggested by the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT In FIG. 1 is shown, in a schematic illustration which is not drawn to scale, a ski body I, having a forward portion, or shovel portion, which is curved upwardly. A protective edge profile, of which the vertical leg portion 4 is clearly visible in FIG. 1, is embedded within body I. The portion of the edge profile which runs inside the shovel portion 2 of the ski has a series of recesses 3 in its vertical leg portion 4. The edge profile is thus firmly anchored in the shovel portion 2 of ski body 1, by virtue of the body material penetrating the recesses 3 during casting of the ski body. Instead of providing open recesses 3, as shown in FIG. 1, there may also be provided a series of plain holes across the vertical leg portion 4 of the edge profile, without interrupting the upper edge portion thereof. This upper leg portion, thus embedded within the ski body, adjoins at its lower end a horizontal leg portion 5, as shown in FIGS. 2-9, the horizontal leg portion representing the exposed pan of the protective profile, being placed in flush alignment with the running surface and with the outer edge of the ski body.

The vertical leg portion 4 of the protective edge profile may be joined to the horizontal leg portion either at its inner edge, as shown in FIGS. 2, 4, S, 7 and 9 so as to define an angle profile, or L-profile, or it may adjoin the horizontal leg portion 5 between its inner and outer edges, as shown in FIGS. 3 and 6, so as to define a T-profile.

In most cases shown, the upper edge portion of the vertical leg 4 is horizontally enlarged, thereby positively retaining the edge profile in the vertical direction against separation from the ski body 1. In FIG. 2, the enlarged upper edge portion of the leg 4 is a rounded bead 7; in FIG. 6 the upper edge portion is similarly enlarged at 7', but trapezoidal in cross section. Both these profiles require a rolling or drawing operation for their manufacture.

In FIG. 3 is shown an embodiment of the protective edge profile in which its vertical leg 4' is tapered for increasing wall thickness toward its upper edge portion, having a cross-sectional shape of a wedge, by virtue of which the protective edge profile is retained in the vertical direction.

The embodiment of FIG. 4 features a narrow horizontal ledge portion 8, adjoining the vertical leg 4 of the edge profile in the form of a T. This shape provides an improved vertical hold of the protective edge profile inside the ski body, while minimizing any deflectioninduced friction between the protective profile and the ski body 1. A similar horizontal ledge 10 is provided in the embodiment of FIG. 5, where the protective edge profile has the overall shape of a channel, or C-profile.

Next, the horizontal ledge may also be provided as shown in FIG. 7, where the ledge 9 extends in the direction opposite to that of the horizontal leg 5, giving the protective edge profile the cross-sectional shape of a Z. Both the profile of FIG. 5 and that of FIG. 7 may be produced from sheet metal, in a simple bending or drawing operation. In this case, the holes or recesses 3 for the shovel portion 2 of the ski may be cut into the sheet metal before it is being bent into the desired C- shape or Z-shape.

FIG. 8 shows an embodiment of the invention in which the undercut cross-sectional outline is obtained through a kink in the vertical leg portion, the lower section ll of the latter being inclined at an acute angle in relation to the horizontal leg portion 5, while the upper section 12 of the upright leg portion extends vertically into the ski body I.

FIG. 9 shows a second possibility of realizing vertical retention, without an enlarged upper edge portion of the vertical leg portion 4, the retaining ledge 13 being provided in the form of an inwardly curved margin of the vertical leg portion 4.

In all cases, the protective edge profile extends from the tip of the ski body, through its shovel portion 2, and along the remainder of the ski body 1. The vertical leg 4 of the protective edge profile, being surrounded on all sides by the ski body 1, thus provides a safe vertical engagement between the leg 4 and the ski body I, while the recesses 3 additionally provide a longitudinal anchoring effect between the edge profile and the ski body I in the shovel portion 2 of the latter. The edge profile is longitudinally movable in relation to the ski body I in the remaining portion of the latter. Thus, the flexibility of the ski body is not negatively affected by the necessary deflection of the protective edge profile, as the latter is no longer stretched under deflection of the ski. The earlier-mentioned application of an antifriction coating on the vertical leg 4 of the protective edge profile insures that the longitudinal mobility of the profile inside the ski body is established at the time of the casting operation, as the ski body 1 itself exhibits a greater longitudinal shrinkage than the edge profile, during cooling and curing of the ski body.

Although, in the foregoing disclosure, the several embodiments of the protective edge profile illustrated and described feature a vertical embedded leg portion, this should not be seen as a limitation, since that leg portion may also be inclined at an angle of more or less than 90 in relation to the horizontal leg portion.

ln all cases, the engagement between the edge profile and the surrounding material of the ski body has the characteristics of a longitudinal guide, the protective edge profile being capable of sliding longitudinally in relation to the surrounding material of the ski body, while being retained against separation from the latter, by virtue of the aforementioned undercut configuration.

It should thus be understood that the foregoing disclosure describes only preferred embodiments of the invention and that it is intended to cover all changes and modifications of these examples of the invention which fall within the scope of the appended claims.

I claim:

1. A ski structure comprising:

a ski body of cast plastic material having a smooth bottom running surface and a shovel portion at its forward end;/and

a protective edge profile of hard, wear-resistant material having a substantially horizontal leg portion thereof in approximate alignment with the running surface of the ski body and an upright leg portion thereof embedded in the ski body; and wherein:

the upright leg portion of the edge profile is retained in the ski body against disengagement therefrom in the vertical direction, by virtue of an undercut cross-sectional engagement outline between it and the surrounding material of the ski body;

the protective edge profile is longitudinally continuous and smooth in outline so as to create matching continuous and smooth contact surfaces in the cast ski body along which the edge profile is capable of sliding longitudinally while being retained as mentioned; and

the shovel portion of the ski body and the protective edge define between them means for longitudinally retaining the forward end portion of the edge profile against said shovel portion.

2. A ski structure as defined in claim I, further comprising an anti-friction coating on at least those surface portions of the edge profile that slide longitudinally against surrounding ski body material.

3. A ski structure as defined in claim 1, wherein the longitudinal retaining means includes a series of recesses in the upright leg portion of the edge profile, which recesses are engaged by the material of the ski body, by virtue of the latter being cast around said upright leg portion.

4. A ski structure as defined in claim 3, wherein the upright leg portion of the edge profile is oriented substantially vertically and has an enlarged upper edge portion providing said undercut crosssectional engagement outline.

5. A ski structure as defined in claim 4, wherein the enlarged upper edge portion of the vertical leg portion has the form of a longitudinal bead.

6. A ski structure as defined in claim 4, wherein the enlarged upper edge portion of the vertical leg portion forms a substantially horizontal ledge portion which overhangs the vertical leg portion on at least one side.

7. A ski structure as defined in claim 4, wherein said vertically oriented, upright leg portion adjoins the horizontal leg portion between its edges, in the manner of a T-junction.

8. A ski structure as defined in claim 4, wherein said vertically oriented, upright leg portion adjoins the horizontal leg portion of the edge profile at that edge which adjoins the ski body running surface, in the manner of an angle junction.

9. A ski structure as defined in claim 8, wherein:

the enlarged upper edge portion of the vertical leg portion is a substantially horizontal ledge adjoining the latter in a second angle junction; and

the horizontal leg portion, the vertical leg portion, and the horizontal ledge portion of the edge profile have the same wall thickness, being portions of a shaped strip of metal.

10. A ski structure as defined in claim 3, wherein the recesses in the upright leg portion of the edge profile form interruptions in said leg profile, thereby rendering the edge profile more flexible within the shovel portion of the ski body.

Claims

1. A ski structure comprising: a ski body of cast plastic material having a smooth bottom running surface and a shovel portion at its forward end;/and a protective edge profile of hard, wear-resistant material having a substantially horizontal leg portion thereof in approximate alignment with the running surface of the ski body and an upright leg portion thereof embedded in the ski body; and wherein: the upright leg portion of the edge profile is retained in the ski body against disengagement therefrom in the vertical direction, by virtue of an undercut cross-sectional engagement outline between it and the surrounding material of the ski body; the protective edge profile is longitudinally continuous and smooth in outline so as to create matching continuous and smooth contact surfaces in the cast ski body along which the edge profile is capable of sliding longitudinally while being retained as mentioned; and the shovel portion of the ski body and the protective edge define between them means for longitudinally retaining the forward end portion of the edge profile against said shovel portion.

2. A ski structure as defined in claim 1, further comprising an anti-friction coating on at least those surface portions of the edge profile that slide longitudinally against surrounding ski body material.

4. A ski structure as defined in claim 3, wherein the upright leg portion of the edge profile is oriented substantially vertically and has an enlarged upper edge portion providing said undercut cross-sectional engagement outline.

9. A ski structure as defined in claim 8, wherein: the enlarged upper edge portion of the vertical leg portion is a substantially horizontal ledge adjoining the latter in a second angle junction; and the horizontal leg portion, the vertical leg portion, and the horizontal ledge portion of the edge profile have the same wall thickness, being portions of a shaped strip of metal.