US2510794A

US2510794A - Ski having concave sides

Info

Publication number: US2510794A
Application number: US782643A
Authority: US
Inventors: Beerli Louis
Original assignee: Individual
Current assignee: Individual
Priority date: 1946-11-01
Filing date: 1947-10-28
Publication date: 1950-06-06
Anticipated expiration: 1967-06-06

Description

June 6, 1950 L.. BEERLI sx1 HAVING coNcAvE sInEs Filed oct. 28, 194'? Patented June 6, L1950 -Luuisneer1i,.Engelberg,switzerland. f

npplieseea'ocwberizs, :In Switzerland Nove 'i sains. (creed-1; ist

'Ihesides ofaJskias-fmade today, see'nli-n the vlongitudinal axis thereof, are `inward-ly arched along a curve beginning at theends of the run- 'fninggfa-ceand extending at -a uniform curvature.

The: presentfdayski:-hasagminimunr width lunder the foot-plateyand maximum widthsfatthe greatest permissibleidistances fromithef-midpoint iaswinei or iis-murmuring transversely eversloping Pis,'forced:into/'tire snow yunder `'acmanimurn force @at thefpointsaof Imaxim-um width, e.atf:the end :,poitioris.` 4113,11; performance .of swings thus-is -renfdered very -disfiiculu` as; thefmoment 4of resistance vwhich=-isein--fo1fziiositionI to the swing, increases with theplengthfo theiski. v

In vorder to decrease the saires'istancafskis have beenfbufilt, theasides-,of whichareprectilinear vor even' arched? outwardly. In. the lattery case Vami: when:oer-iorxnng.'a'swing` yonafharll and snow surracal emilyl the center portion of the ski grips the latter so 'that the ski practically ndsznofresistance. Such a ski may rock on its outward arch even on a plane surface, and is no y longer controlled byv the rider.

`Rectilinear side;.faces also did' not yproveipractical, since-even in case of vslightly rising-snm! surfaces-the skewed ski rocks about its center, and is no longer 'sufficiently controllable. s

The-subject matter of my. present inventionisfa skilwhichf overcomes the said inconveniencies of theknownskis.

In the ski according to my invention, the sides fore and aft of the binding tackle each have a point at which the curvature of the side lines changes its direction. The distance between the said points of inflexion amounts to 85%, as a maximum, of the length of the running face measured between the root of the scoop and the rear end of the ski. Forward and rearward of the said points, the side lines are convexly curved, i. e. deilected inwardly toward the center line of the ski.

The rear point of inflexion preferably is spaced from the rear end of the ski by more than of the total length of the ski, or-in other wordsthe maximum width of the rear portion of the ski is situated at a distance of more than 10% of the ski-length from the rear end of the ski.

Portions of the sides between the scoop root and the beginning of the end curvature, preferably are curved outward.

The ski also, could be bent upward, scoop like', at its rear end. The beginning of the end-curvature in the latterl case, would have to be replaced accord Ytstarts-:to .ur efunwardlv.

plaira ty or structural designs are zshown.

fbyway'oiexampiesin the" accompanying drawing, in which y tig.v ,shows Aaski 'of zconventiona'lioutlines, in

:rug sidevi'ewferanrstformorinvenuon,

fE Vp planviewfof'fsuchfr'st formja'nd' Y iF-igea e. .eachfshcw' affurthertform of invention:

fia tneeenventienarfskr shown in; nigga are sidesfare "archedlnwardly, itheusualpradiiis o f 'curvature aamountingto 'Z0-@8U metres.. Sucharch tends' .approximately Yfrom; 'the' starting `point aorsther'eareend curvatureg upwtorthe; root A jof the scoop at the front end portionY ot the ski. TIiheigmaxinrum wfdthfa. ofthe s'kif Yis'at A; e; at they-point-where Y:th recoup-startetecurve upn u thelipiof h 'Scoopbein'g'eloinches The width y,ocl'fhez'slci s-gradually-'decreasedy inthe-dilrect/ion:towrarr1. th idpointf-off. the ski, attains mum-i e ateo' te wnereituelinstepef the cot!ijs'lo'cated,1 and is; gradually "increased I teetliewidth@y beat-fthe; rear 'end'` ofthe ski, The

When the skier performs a swing on a hard surface, such conventional ski is no longer positively guided as soon as the radius of the surface swell or rise is smaller than the radius R of the ski side arch. When, however, such former radius is greater than R, the ski-which is set on edge during a swinging movement-mainly is supported at A and B, i. e. at the ends of the effective running face. Points A, B cutharder into the snow, and the resistance to a swing is increased.

In the first form of invention shown in Figs. 2 and 3, the inwardly arched portion of the ski sides curved on radius R1, extends only over a part y of the running face between root A of the scoop and point B of the rear end curvature. Two outwardly arched portions, curved on a radius R2 and adjoining the central inwardly arched portion, are provided for. At the transition from the inwardly to the outwardly arched portions, points of inflexion X and Y are situated. Fore and aft respectively of the latter points, the sides 11the -Poihtiat which: the' rear` scoop only in depressions which have are outwardly arched. The maximum widths ai, b1 of the ski are spaced by a distance g which is substantially shorter than distance e of the conventional ski according to Fig. 1. Such points of maximum widths are situated approximately at equal distances from point C of the ski, i. e. at the point of support for the skiers instep. The maximum width of the rear portion of the ski, bi, is spaced from the rear end of the ski at a distance which amounts to more than of the length of the ski, and the inward arch extends the end of the ski.

By reason of the fact that the points of maxi-:5" mum width are brought substantially nearer each other than in the conventional ski according t6 Fig. 1, the resistance encountered when swinging on a flat surface, is materially decreased,V

Rs of the inward arch is held comparatively small, in order to permit of positively guiding the ski also on rather pronounced ground swells.

:The lateral faces of the ski end and the ski front 4portion at the root of the scoop hug a circular arc of radius R4. The ends of the ski, when the latter is set on edge, thus contact` the ground a radius equal to or less than R4. r

In the example shown in Fig. 5, the portions i-which adjoin the inward arch fore and aitare aligned on a straight line'i which is inclined relative to the center line 'of the ski. 'Ihe maximum rear width is situated approximately at the same distance from the ski end as in the examples 'according to Figs. 3 and 4, but the maximum `front width is set nearer to the root of the scoop and also may be spaced (as in the conventional ski) less than 15% of the ski length from the tip 'of the scoop. Further, the length or chord of the inward arch is less than 280 times the rise l? thereof. f

In the example shown in Fig. 6, the sides extend-intermediate of the root of the scoop and forward point of curve Y-parallel to the center 4 line of the ski over a distance n which amounts to at least 10% of the length of the running surface. The ski rear portion m, situated ntermediate of the ski-end and the rear point of curve X, is rectilinear, and its edge is inclinedrelative to a straight line passing through points X and Y-through the same angle a as the edge of the parallel front portion n.

What I claim as new and desire to secure by Letters Patent, is:

1. A ski having inwardly curved sides in which over not more than of the said lengths# as measured between the root of the scoop and each lateral edge fore and aft of the bindingtackle comprises points in which the inward curvature ends and changes, the said points being spaced at a maximum of 85% of the length of the running face intermediate of the root of the scoop and the end of the ski; the parts oi' the said edges fore of one point and aft of the other point having the same shape and being symmetrically arranged with regard to a centre fline which is at right angles to the longitudinal centre line of the ski and passing through the longitudinal middle of the curvature.

' I2. A ski according to claim 1, in which the points at which the inward curvature ends are at equal distances from that point of the ski on'which the skiers instep is located.

--3. A ski according to claim 1, in which the llateral edges of the skiintermediate of said root and the fore end point of the inward curvature Aand intermediate of the end of the ski and the aft end point of the curvature respectively are rectilinear for a distance which amountsvto at 'least 10% of the length of said running face and The following references are of record in the file of this patent:

FOREIGN PATENTS Number Country Date 532,954 Germany Feb. 21, 1930 804,598 France v Aug. 3, 1936