WO1982003183A1

WO1982003183A1 - Electromagnetic safety ski binding

Info

Publication number: WO1982003183A1
Application number: PCT/SE1982/000074
Authority: WO
Inventors: Goeran Sjoenell
Original assignee: Goeran Sjoenell
Priority date: 1981-03-18
Filing date: 1982-03-17
Publication date: 1982-09-30
Also published as: SE444267B; EP0075560A1; SE8101727L

Abstract

This invention relates to the release of a ski binding. The boot is provided on the inner surface with pressure-sensitive cells (6), which are actuated by predetermined loads from the foot and/or leg. At least one electromagnet (4; 8) is provided in the boot and supplied with current, which can be broken by signals from the pressure-sensitive cells (6) in the case when they are loaded, and at least one armature (3) attracted by the electromagnet is arranged so that, upon breaking of the current, the binding of the armature to the electromagnet ceases, and the boot (1) disengages from the ski (2).

Description

ELECTROMAGNETIC SAFETY SKI BINDING

This invention relates to a method at the release of ski bindings, and to a ski binding intended to bring about this release method.

Ski bindings, and especially slalom bindings, must be constructed so that they release when the ski boot is loaded in certain directions by predetermined forces. Such forces, at which the ski binding is to release, can be adjusted optionally. The aim is that the force for releasing the binding is sufficiently great for rendering normal use of the ski possible, but sufficiently small for preventing at accidents legs and feet to be injured. Normally, the adjusting of the ski binding is carried out by a specialist, and the principle is to adjust a spring tension. Even when a correct adjustment of the binding can be obtained,optimum adjustment is not achievable due to the fact, that the binding can be affected by forces having varying directions. An adjustment which is correct for preventing leg fracture at fall forward, does not imply automatically that the binding is adjusted correctly when, for example, the foot is twisted in the binding. Very often the skier himself adjusts the release force of the binding.

In order to facilitate the accurate determination of the release force, mechanical bindings also have been combined with sensing members arranged in the ski boot and intended by action of a predetermined force to release the binding. By the combination with mechanical bindings, and as the sensing members only sense horizontal or vertical forces in one or several points in the boot, optimum release of the binding is not obtained, either.

In view of the aforesaid, leg fractures use to occur at slalom skiing. These fractures, besides, normally are very complicated.

The present invention relates to a ski binding, which acts according to an entirely new way of thinking, as stated in the characterizing clauses of the claims. By the invention, a release of the binding is obtained, i.e. the ski loosens from the boot instantly as soon as an unnormal pressure arises between the boot and foot and/or leg in the boot.

The invention operates with a purely magnetic binding between boot and ski. This binding is broken instantly on order from pressure-sensitive cells, which are located in selected places on the inner surface of the boot. Forces not injurious per se when acting alone can, when combined, give rise to leg fracture. According to the invention, this is excluded because the pressure-sensitive cells in different areas of the boot are combined with each other and release the binding even when the individual forces each alone would not open the binding.

The invention is described in greater detail in the following in the form of embodiments and with reference to the drawing, in which Fig. 1 is a lateral section of one embodiment of the invention, Fig. 2 is a corresponding section through a second embodiment of the invention, Fig. 3 shows boot and ski dashed and schematically with inserted coils according to the latter embodiment. In the Figures, 1 designates a boot, slalom boot, and 2 designates the ski. On the upper surface of the ski, in a place where the boot is to be positioned, a plate 3 of soft-magnetic material is located. Into the sole of the boot 1 an electromagnet 4 is cast, the lower surface of which lies in the plane of the sole surface. At the embodiment shown, the plate 3 is provided with a pair of elevations in the form of cone-shaped warts 5, which engage with corresponding recesses in the sole of the boot. The inner surface of the boot 1 is provided with pressure-sensitive cells, which are marked in the form of spots 6 and distributed uniformly on the boot inner surface. The cells may, for example, be in the form of piezoelectric elements, which upon load emit a current pulse. From a suitable current source (not shown) the electromagnet 4 is supplied with current, which via a suitable connection with amplifier can be broken by the current impulse or signal from the cell 6.

It is possible by accurate studies to map the inner surface of the boot in respect of different pressure loads in different places in the boot, depending on the process of accidents to be expected. As soon as a predetermined pressure arises in an area of the boot, the cell or cells in this area are actuated and break the current to the electromagnet 4. The ski hereby disengages from the boot. By coupling together via microcomputer different areas of the boot, these areas can be effected to co-operate for different types of loads. In order to prevent, for example, torsion fracture of the leg, the heel and toe areas of the boot can be coupled together "diagonally". Parts of the inner surface of the boot can be coupled together "diagonally" with other, parts of lower location of the boot inner surface.

It is, therefore, not necessary to line the entire inner surface of the boot with pressure-sensitive cells 6, but, as indicated schematically in Fig. 2, it is possible to provide only certain parts of the inner surface of the boot with such cells. Such parts are designated in Pig. 2 by a, b, c.

According to Fig. 2, the electromagnet 4 consists of two metal bars 7, which are cast into the sole of the boot in parallel with each other. Each bar is provided with five downward directed cylindric metal cylinders 8,which form cores for coils 9. The coils are wound of 500 windings and connected in series, supplied by a 9 V, 1,0 A battery, which, for example, can be stored in a pocket in the boot (not shown) or in another suitable place. The current to the coils 9 is broken in the way described above at disadvantageous load on the foot and/or leg. The boot 1 is guided in lateral direction on the ski by means of low studs 10 attached in suitable arrangement on the ski. These studs have no binding effect per se between ski and boot.

It is, of course, possible within the scope of the invention to use other solutions for achieving the desired effect, viz. to actuate via pressure-sensitive cells in the ski boot an electromagnet so that the ski instantaneously is disengaged from the boot.

It is possible by means of a magnet coil consisting of about 5000 windings supplied from a 9 V, 1,0 A battery during 15 hours to obtain a holding-together force of about 100 kp, which is sufficient for a purely magnetic binding, i.e. without any mechanic auxiliaries, for example according to Pigs. 2-3.

A current source suitable for the purpose can be used which is carried, by the skier and built-in in the boot, or attached to the ski. In the latter case electric connection to the boot must be provided. Instead of studs 5 according to Pig. 1, of course, also edge guides for the boot can be used.

Claims

1. A method at the release of a ski binding, c h a r a c t e r i z e d i n that pressure-sensitive cells arranged on the inner surface of the ski boot for releasing the binding are subjected to pressure load on parts of the foot and/or leg, which cells thereby emit a control signal for breaking the current through one or several electronagnets, the electromagnetic fields of which, which co-operate with one or several armatures retaining the ski at the boot, instantaneously cease, and the boot disengages from the ski.

2. A ski binding for instantaneous release, disengaging the ski from the ski boot, c h a r a c t e r i z e d i n that the boot (1) is provided on the inner surface with pressure- sensitive cells (6), which can he actuated by a predetermined pressure originating from the foot and/or leg, and at least one electromagnet (4;8) suppled with current, which can be broken by signals from the pressure-sensitive cells (6) in the case of their loading, and that at least one armature (3) attracted by the electromagnet is arranged so, that upon breaking of the current the binding of the armature to the electromagnet ceases and the boot (1) disengages from the ski (2).

3. A ski binding as defined in claim 2, c h a r a c t e r i z e d i n that the electromagnet (4) forms a portion of the sole of the boot (1), and the armature (3) is a portion of the ski (2), on which the boot is positioned, which ski is provided with elevations (5) intended to engage with the boot and guide the same to correct position on the ski.

4. A ski. binding as defined in any one of the claims 2 or 3, c h a r a c t e r i z e d i n that the pressure-sensitive cells (6) are arranged on the entire inner surface of the boot, with exception of the sole.

5. A ski binding as defined in any one of the claims 2-4, c h a r a c t e r i z e d i n that the pressure-sensitive cells (6) are arranged in areas (a-c), which are especially exposed to pressure load of leg and foot at such a process which is to release the binding.