US2276826A

US2276826A - Magnetic ski harness

Info

Publication number: US2276826A
Application number: US404656A
Authority: US
Inventors: Frederick D Crowther
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1941-07-30
Filing date: 1941-07-30
Publication date: 1942-03-17
Anticipated expiration: 1959-03-17

Description

March 17, 1942.

F. D. CROWTHER- 2,276,826

MAGNETIC SKI HARNESS Filed July 30 194i Inventor-:- Frederick D. Cr-owther',

Hi Attorney.

= Patented Mar. 17, 1942 MAGNETIC SKI HARNESS Frederick D. Crowther, Scotia, N. Y., assignor to General Electric Company, a corporation of New York Application July 30, 1941, Serial No. 404,656

9 Claims.

This invention relates to ski bindings or harnesses by which a ski boot or shoe is held to a ski, and more particularly to means for maintaining the heel of a ski boot or shoe on a ski.

In skiing, in order to obtain proper control of the skis, it is desirable in most circumstances to keep the heels against the skis. Various methods have been used in the past to accomplish this result. According to one method, a spring is fastened around the ankle or instep, the ends being fastened to the ski in back of the foot. This method makes walking uphill extremely diificult. According to another method, the binding comprises a strap extending around a groove in the heel, a spring usually being incorporated. The strap assembly is pivoted against the ski below the level of the toe so that as the heel'is raised from the ski, the force tending to pull the heel down is increased. This method is generally satisfactory for downhill running but is not particularly satisfactory for climbing because the greater the distance between the heel and the ski, the more strain there is on the foot and the tighter the binding becomes so that in case of a fall in which the skier falls forward, it often happens that the ankle or leg is broken.

It is an object of.my invention to provide a new and improved ski harness which eliminates the foregoing disadvantages.

It is another object of my invention to provide a new and improved ski harness which is simple and rugged in construction, and eincient and reliable in operation.

Still another object of my invention is to provide a new and improved ski harness utilizing permanent magnets.

It is also an object of my invention to provide a new and improved magnetic ski harness with means for reducing the magnetic pull when desired in order to facilitate climbing.

Other objects and advantages of my invention will become apparent as the following description proceeds, and the features of novelty which characterize my invention will be pointed out, with particularity in the claims annexed to and forming a part of this specification.

For a better understanding of my invention reference may be had to the accompanying drawing in which Fig. 1 is a. perspective view of a ski boot in association with a portion of a ski illustrating the cooperation between the magnet and an armature. Fig. 2 is a cross sectional view of the heel and ski shown in Fig. 1. Fig. 3

illustrates a detail of my invention and Figs. 4 F

and 5 illustrate a second embodiment of the invention shown in Figs. 1 and 2. I

Referring to the drawing, there is illustrated a ski harness for maintaining a ski boot II or the like in association with a ski In. In order to determine the location of the foot on the ski, I have provided a pair of toe plates l2 having opposed inturned upper edges or lifts to provide a channel or groove for the reception of theedge portion H of the sole of the boot I I. In order to hold the boot to the toe plate, there is provided a two-part heel strap [5, one part being provided with a buckle IE to permit fastening of the two parts of the strap and to permit adjustment of the length of the strap to the size of the boot. The ends of the straps are suitably pivoted to suitably arranged lugs on the toe plates as indicated by the numeral IT. The centrally disposed portion of the strap I5 ispreferably provided with a substantially circular cross section'as indicated by the numeral I8 in Fig. 2 and arranged for reception in a groove IS in the heel 20 of the boot.

I have provided means for normally maintaining the heel of the boot in association with the ski. As illustrated in the drawing, this means comprises a permanent magnet assembly or element 2| disposed either in association with the heel of the boot or in association with the ski and a second magnetic element, as an armature 22, associated either with the ski or with the heel of the boot, respectively. The first suggested arrangement is illustrated in Figs. 1 and 2 while the latter arrangement'is illustrated in Figs. 4 and 5 wherein the numeral 2 l represents the magnet assembly secured to the ski and the numeral 22' indicates the magnetic armature associated with the boot. The latter arrangement has the advantage that the magnet is not subject to damage during walking of the skier when the ski is not employed.

In the arrangement shown in Figs. 1 and 2, the permanent magnet assembly is suitably secured within a recess 23 in the heel 20 of the boot as by means of non-magnetic screws or nuts and bolts 24' of brass, for example. The non-magnetic material for the securing means is necessary to prevent short-circuiting of the magnet.

The permanent magnet assembly represented by the numeral 2| comprises a permanent magnet 24 preferably constructed of high coercive force material and positioned b tween two substantially U-shaped pole pieces 25 and 2B of relatively high permeability magnetic material, such as soft iron, for example, and maintained in engagement therewith by securing means. The outer pole piece is of substantially U-shape having leg portions 21 in the form of flanges which extend from the flat interconnecting portion of the U. The other pole piece 26 which engages the opposite end of the magnet 24 is likewise of substantially U-shape and its legs or arms 28 extend. in the same direction as the raised or leg portions 21. The legs are spaced apart a suflicient distance-to form a pair of air gaps. These gaps form a low reluctance shunt or leakage path for the magnetic flux when the armature is removed from the poles of the magnet. The relatively high permeability pole pieces serve to concentrate the magnetic flux at the junction with the keeper or armature and together with the air gaps form a low reluctance shunt or leakage path to carry the flux when the magnet is open-circuited, therebylessening the demagnetization.

As an example of suitable magnetic material for use in the magnet 24, 1 have found that alloys containing iron, nickel and aluminum as the basic or essential ingredients, as described in United States Letters Patent No. 1,947,274 and No. 1,968,569 to William E. Ruder, and Nos. 2,027,994 to 2,028,000, inclusive, to Tokushichi Mishima, are highly satisfactory materials for forming a permanent magnet used with my invention. If desired,- however, the magnet composed of the aforementioned alloys may be formed by a sintering process as disclosed in United States Letters Patent No. 2,192,743 to Goodwin H. Howe.i Magnets made from. such alloys exhibit a very high coercive force. Inasmuch as it is the coercive force which determines the ability of a permanent magnet to resist demagnetization, magnets made from such materials may consequently be made much shorter in length than those made from low coercive cover plate 33 of non-magnetic material, as brass, for example, which may be interposed between the armature and the magnet thereby'lengthening the air gap and weakening the magnetic at-' traction between the armature and magnet. The cover plate shown is in the form of a longitudinally extending clip having an inwardly and forwardly extending flange 34 to engage the front edge of the armature and a transverse member 35' suitably attached to the clip 33 and having on each end a downwardly and inwardly turned flange 36 for engaging the side and under surfaces of the armature. It will be seen that when the heel is down the non-magnetic clip will separate the magnet poles and the armature. Other means for accomplishing this purpose will be apparent to those skilled in the art. For example, the result may be obtained by providing a steel or other magnetic material member or plate which may be aflixed to the magnet when desired. In any case, it is desirable to provide a removable member which may be carried in the pocket and applied to the binder apparatus when struction to the magnetillustrated in Figs. 1 and v 2. In order to retain the magnet 2| on the ski, I have provided a strap 39, preferably of nonmagnetic material, in order to prevent shortcircuiting the magnet, suitably secured at either force materials and such magnets will maintain their magnetism almost indefinitely without appreciable diminution. Consequently, a maximum amount of magnetic energy is obtained from a given volume of magnetic material, so that for a particular application less magnetic material will be required.

In. order to hold the boot to the ski, I have provided an armature of magnetic material, such as soft iron, suitably secured to the ski. In the form of my invention shown inthe drawing, I have provided a pivotal support for the heel plate 22 by suitably securing the heel plate to a pin 29 which, in turn, is suitably journaled in brackets 30 on either side of the ski, the brackets being suitably secured as by screws 3|.

In order to prevent side slip of the heel, the brackets 30 have been extended above the face or surface of the heel plate as indicated by the numeral 32. heel plate, separation of the boot from the heel plate by levering action is minimized.

In operation, the heel will normally be held in association with the ski by the magnetic attraction between the permanent magnet assembly 2! and the heel plate 22. However, pressure exceeding a predetermined amount will cause the heel to be withdrawn so that in case of a fall danger of breaking a leg or ankle is minimized.

In order to facilitate climbing on skis it is desirable to provide an arrangement which permits the heel freely to lift from the ski. An arrangement for permitting the heel to be freely withdrawn from the ski under such conditions is illustrated in Fig. 3. There is illustrated a By thus pivotally supporting the' end thereof to the ski as by means of screws 40.

If magnetic material is used for the strap 39, it will be necessary to insulate the strap from the magnet. As shown in Figs. 4 and 5, the magnet 2| is loosely retained by the strap 39, for limited movement normal to the ski in order to permit a wobbling action in order to prevent separation of the armature from the magnet by lever action. Thus, in both forms of my invention, I have provided means movable out of its normal plane in engagement with the heel or ski to prevent such separation by lever action. If desired, the magnet and strap maybe covered by a cover plate 4| of non-magnetic material. The disposition of the armature 22' in a recess in the heel provides a recess within which the magnet assembly fits, thereby minimizing any tendency of the heel of the boot to sideslip while skiing.

While I have shown a particular embodiment of my invention, I do not desire my invention to be limited to the particular construction shown and described and I intend in the appended claims to cover all modifications within the spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. A device for securing skis to boots comprising a shoe member and a ski member, a permanent magnet on one of said members and a cooperating magnetic armature on the other of said members, the magnetic attraction between the permanent magnet and the armature serving to retain the heel of the boot in association with the ski.

2. A device for securing skis to boots comprising a shoe member and a ski member, a permanent magnet on one of said members and a cooperating magnetic armature on the other of said members, the magnetic attraction between the permanent magnet and the armature serving to retain the heel of the boot in association with the ski, and removable means for lessening the magnetic attraction between the magnet and the armature.

3. A device for securing skis to boots comprising a shoe member and a ski member, a pair of magnetic elements, one of said elements comprising a permanent magnet and the other of said elements comprising a magnetic armature, one of said elements being disposed in association with the heel of said shoe member and the other of said elements being disposed in association with said ski member, one of said elements being free to move out of its normal plane in order to minimize separation of said elements by lever action.

4. A device for securing skis to boots comprising a shoe member and a ski member, a pair of magnetic elements, one of said elements comprising a permanent magnet and the other of said elements comprising a magnetic armature, one

of said elements being disposed in association with the heel of said shoe member and the other of said elements being disposed in association with said ski member, one of said elements being free to move out of its normal plane in order to minimize separation by lever action, and means associated with one of said elements for preventing side slip of said heel with respect to said ski member.

5. A deviceior securing skis to boots comprising a shoe member and a ski member, a pair 0! magnetic elements, one or said elements comprising a permanent magnet and the other of said elements comprising a magnetic armature, one of said elements being disposed in association with the heel of said shoe member and the other of said elements being disposed in association with said ski member, one of said elements being free to move out of its normal plane in order to minimize separation by lever action, and means for lessening the magnetic attraction between said elements in order to enable the heel to be lifted relatively easily from the ski.

6. A device for securing skis on boots including for each ski an armature, means for pivotally supporting said armature on said ski and a cooperating permanent magnet secured to the heel of the boot.

'I. In a device for securing skis to boots, the combination of a permanent magnet within a recess in said heel, an armature, means for pivotally supporting said armature on said ski, and means for preventing side slip of said heel when said heel is adjacent said ski.

8. In a device for securing skis to boots, the combination of a permanent magnet within a recess in said heel, an armature, means for pivotally supporting said armature on said ski, and means for preventing side slip of said heel when said heel is adjacent said ski, said means comprising an extended portion on each of said supporting means, said extensions extending above the surface of said armature.

9. In a device for securing a ski to a boot, the combination of a permanent magnet mounted on said ski for limited movement normal to said ski and a cooperating magnetic armature car-