WO2013042154A1

WO2013042154A1 - Ski - or trekking- stick equipped with magnetic- inductive harvester device for electric generation

Info

Publication number: WO2013042154A1
Application number: PCT/IT2012/000280
Authority: WO
Inventors: Aurelio Soma'; Giorgio DE PASQUALE; Federico FRACCAROLLO
Original assignee: Politecnico Di Torino
Priority date: 2011-09-22
Filing date: 2012-09-12
Publication date: 2013-03-28
Also published as: ITTO20110844A1; EP2758141A1; EP2758141B1

Abstract

A ski- or trekking-pole (1) is described, composed of at least one shaft (3) interposed between at least one handle (5) and at least one ring (7) placed at the two opposite ends of the shaft (3), comprising at least one harvester device (9) for generating electric current composed of at least one moving magnetic element (11) sliding along at least one sliding guide (13); at least one fixed magnetic element (15) arranged in the vertically lower end of the sliding guide (13), the fixed magnetic element (15) and the moving magnetic element (11) sliding along the sliding guide (13) being mutually oriented in such a way as to oppose the two faces with the same polarity in order to generate a magnetic repulsion force; and at least one first winding (17) made of electrically conductive material adapted to concatenate a magnetic field of the moving magnetic element (11) sliding along the sliding guide (13).

Description

SKI - OR TREKKING- STICK EQUIPPED WITH MAGNETIC- INDUCTIVE HARVESTER

DEVICE FOR ELECTRIC GENERATION

SKI- OR TREKKING-RACKET EQUIPPED WITH MAGNETIC- INDUCTIVE HARVESTER DEVICE FOR ELECTRIC GENERATION

The present invention refers to a ski- or trekking-racket equipped with harvester device for electric generation.

As known, an harvester is a device that is able to capture energy from external sources present in the surrounding environment (solar energy, thermal energy, kinetic energy from vibrations, etc.) and transform it into electric energy that can be exploited, for example, by other user devices or electronic systems. It is then clear how the environment advantageously is an abundant source of energy, if compared with the amount of energy that can be stored in common accumulators, such as batteries and the like.

In particular, among the various energy sources that can be used, vibrations are advantageously capable of being exploited for making harvester devices: in fact, when a device is subjected to vibrations, it is possible to use an inertial mass suitably connected to an electric transducer to transform kinetic energy into electric energy. In the years, therefore, harvester devices have been developed that are able to transform kinetic energy provided by vibrations into electric energy, by exploiting different operating types, based, for example, on the piezoelectric principle, the electrostatic principle (through the use of capacitors with plane parallel faces) or the electromagnetic principle (exploiting the electromagnetic induction phenomena) . Currently, such harvester devices have also ben used as accessories to commonly used objects, such as pieces of clothing or sports articles, in such a way as to allow the users of such objects to have available a source of electric energy generated by their own movement to supply or recharge possible electric apparatuses, like cellular phones, MP3 readers, smart-phones, palmtop computers, etc., even in case of unavailability of a connection to mains for recharging the related supply batteries.

EP1506800, GB1270457, DE3317600 disclose ski- rackets equipped with current generating systems. In particular: EP1506800 discloses a ski-racket in which the generation of current occurs through the compression of a piezoelectric material created by abutting the racket shoe onto the ground;

- GB1270457 discloses a ski-racket in which the generation of current occurs through compression and flexure of a piezoelectric material; it can further comprise transmissions in the stick shoe to move electromagnetic generators, that can be magnets or motors, through a rack connected to the racket show itself;

DE3317600 discloses a walking stick in which the generation of current occurs through a generator like a mercury tube of a dynamo.

The art however does not propose any ski- or trekking-racket in which the electric generation occurs through a harvester device of the magnetic- inductive type, in particular with asymmetric magnetic constraint.

Moreover, above all in a sports discipline like alpine ski, it is extremely needed to always guarantee the necessary degree of electric charge to the batteries of the searching device in case of an avalanche (typically called ARVA) that ensures its correct operation and with its due continuity. The art however does not propose any ski- or trekking-racket equipped with a searching device in an avalanche that is self-supplied by an harvester device housed in the racket itself.

Moreover, the art proposes harvester devices equipped with symmetric magnetic suspension^'s in which a moving magnetic element is interposed between two fixed magnets with their respective polarities, in order to create, in both these fixed magnets, magnetic repulsion forces towards the moving magnet: these known systems however allow having the moving magnet in a static and dynamic equilibrium due to the effect only of the magnetic forces, independently from the direction of the force of gravity.

Document DE-Al-10 2007 029689 discloses a ski- racket according to the preamble of Claim 1, in which, however, there are no fixed magnets and the moving magnet is compelled to perform only small oscillations due to the presence of two springs pushing on both its sides: such small oscillations are therefore capable of generating only a small current, which is not suitable for supplies like those mentioned in the present invention.

Object of the present invention is solving the. above prior art problems, by providing a ski- or trekking-racket equipped with a magnetic-inductive harvester device for electric generation.

Another object of the present invention is providing a ski- or trekking-racket equipped with at least one searching device in an avalanche, self-supplied by an harvester device housed in the racket when it is subjected to vibrations when skiing .

Moreover, an object of the present invention is providing a ski- or trekking-racket equipped with a magnetic-inductive harvester device for electric generation with asymmetric magnetic suspension.

The above and other objects and advantages of the invention, as will appear from the following description, are obtained with a ski-racket equipped with a magnetic-inductive harvester device for electric generation as claimed in Claim 1. Preferred embodiments and non-trivial variations of the present invention are the subject matter of the dependent claims.

It is intended that the enclosed claims are an integral part of the present description.

It will be immediately obvious that numerous variations and modifications (for example related to shapes, sizes, arrangements and parts with equivalent functionality) could be made to what is described, without departing from the scope of the invention, as appears from the enclosed claims.

The present invention will be better described by some preferred embodiments thereof, provided as a non-limiting example, with reference to the enclosed drawings, in which:

- Figue 1 shows a schematic side view of a preferred embodiment of the ski-racket according to the present invention;

Figure 2 shows an electric block diagram of a component of the ski-racket according to the present invention; and

Figures 3a and 3b show graphs representing the voltage generated by the racket according to the present invention.

With reference to Figure 1, it is possible to note that the ski- or trekking-racket 1 according to the present invention (for example it can be used for alpine ski) is composed of at least one stem 3 interposed between at least one handle 5 and at least one shoe 7 placed at the two opposite ends of such stem 3. Advantageously, the ski-racket 1 according to the present invention further comprises at least one harvester device 9 for generating electric current composed of:

at least one moving magnetic element 11 sliding along at least one sliding guide 13;

at least one fixed magnetic element 15 arranged in the vertically lower end of such sliding guide 13, such fixed magnetic element 15 and such moving magnetic element 11 sliding along the sliding guide 13 being mutually oriented in such a way as to oppose the two faces with the same polarity in order to generate a magnetic repulsion force which is contrasted only by the force of gravity applied by the moving magnetic element 11 and is capable of pushing the moving magnetic element 11 upwards along a length of said sliding guide 13 which is much greater than the distance between said fixed magnetic element 15 and said moving magnetic element 11; and

- at least one first winding 17 made of electrically conductive material adapted to concatenate the magnetic field of such moving magnetic element 11 sliding along the sliding guide 13.

Preferably, the harvester device 9 comprises at least one second winding 19 made of electrically conductive material adapted to concatenate the magnetic field of such moving magnetic element 11 sliding along the sliding guide 13, such first winding 17 and such second winding 19 being preferably symmetrically arranged with respect to the centre distance axis of the moving magnetic element 11. Each winding 17, 19 is preferably made with copper wire.

Preferably, the sliding guide 13 is made of at least one tubular recess longitudinally obtained inside the stem 3 of the ski-racket 1: obviously, the harvester device 9 as described above can alternatively be arranged in any other position (for example in the handle 5 ) , without therefore departing from the scope of the present invention.

The harvester device 9 of the ski- or trekking-racket 1 according to the present invention is then made of an inductive generator with asymmetric magnetic suspension in which the magnetic poles of the moving magnetic element 11 and the fixed magnetic element 15 are vertically placed inside the racket 1 so that the faces with the same polarity are arranged one in front of the other, and, consequently, such moving magnetic element 11 and such fixed magnetic element 15 are mutually repelled.

The moving magnetic element 11 is therefore free of sliding along the sliding guide 13, but it is suspended above the fixed magnetic element 15 due to the repulsive forces. When the ski- or trekking-racket 1 according to the present invention is taken to vibrate, for example when skiing, the moving magnetic element 11 alternately moves around its equilibrium configuration, inducing a voltage in the two coils 17, 19.

Therefore, differently from what is known in the art, the harvester device 9 according to the present invention preferably comprises a single fixed magnetic element 15 arranged in the lower part of the sliding guide 13 and a moving magnetic element 11. The magnetic suspension force is then provided by the magnetic repulsion of the two magnetic elements 11, 13, since the racket 1, in its normal use configuration, is oriented in such a way that the force of gravity pushes the moving magnetic element 11 downwards, namely towards the fixed magnetic element 15. The harvester device 9 according to the present invention therefore allows having an asymmetric suspension and a longer, stroke of the moving magnetic element 11 inside the sliding guide 13, and therefore with an energy generation efficiency and efficacy that are greater than what is proposed by the prior art.

The harvester device 9 of the ski- or trekking-racket 1 according to the present invention is then able to generate electric current and to supply any electric apparatus suitably connected through connecting means to such harvester device 9: preferably, the racket 1 according to the present invention further comprises at least one wireless searching device, for example ARVA, 20 connected to such harvester device 9, for example by interposing suitable managing means 21, and supplied with current by the harvester device 9 itself.

The ski- or trekking-racket 1 according to the present invention then comprises managing means 21 for the operation of the harvester device 9: in particular, as is possible to note in Figure 2, such managing means 21 comprise at least one electronic _. recharging card equipped, for every winding 17, 19, with at least one rectifying and levelling circuit composed of electric current rectifying means 23, such rectifying means preferably comprising at least one diode bridge with low threshold voltage, electric current stabilising means 25, such stabilising means preferably comprising at least one capacitor, means for accumulating electric energy, comprising for example at least one rechargeable backup battery (for example rechargeable lithium batteries) . Each one of the windings 17, 19 is then connected to its respective rectifying circuit, and in particular to- the above diode bridge, which in turn is connected to its respective capacitor. The capacitor is finally connected to its respective backup battery. The electrodes of the backup battery are then connected, directly or by interposing a suitable connecting means . or cable, to a possible electric apparatus 20 to be supplied with current, for example to the searching device in an avalanche arranged inside or outside the racket 1 according to the present invention.

From experimental test performed on a ski- or trekking-racket 1 according to the present invention like the previously described one, and having sizes and characteristics as included in the following Table 1, values have been measured for the generated electric voltage included in the graphs shown in Figures 3a and

Table 1

In particular, Figures 3a and 3b respectively show graphs having as abscissa the number of samples and as ordinate the generated voltage values representing the voltage generated on the first winding 17 (Figure 3a) and on the second winding 19 (Figure 3b) : it can be noted that the produced voltage can be used for recharging a 3V battery, with a minimum current produced by every coil that is equal to 30 mA. As an example, it can be observed that a searching device during an avalanche ARVA consumes about 10 mA, and therefore, after few seconds of walking, it can continuously transmit. Other possible integrated wireless transmission methods could, obviously, be added and activated upon request.

Claims

1. Ski- or trekking-racket (1) composed of at least one stem (3) interposed between at least one handle (5) and at least one shoe (7) placed at the two opposite ends of said stem (3) , comprising at least one harvester device (9) for generating electric current composed of:

at least one moving magnetic, element (11) sliding along at least one sliding guide (13); ed - at least one first winding (17) made of electrically conductive material adapted to concatenate a magnetic field of said moving magnetic element (11) sliding along said sliding guide (13) ;

characterised in that it further comprises:

at least one fixed, magnetic element (15) arranged in the vertically lower end of said sliding guide (13) , said fixed magnetic element (15) and said moving magnetic element (11) sliding along said sliding guide (13) being mutually oriented in such a way as to oppose the two faces with the same polarity in order to generate a magnetic repulsion force which is contrasted only by the force of gravity applied by the moving magnetic element (11) and is capable of pushing the moving magnetic element (11) upwards along a length of said sliding guide (13) which is much greater than the distance between said fixed magnetic element (15) and said moving magnetic element (11) . 5

2. Ski- or trekking-racket (1) according to claim

1, characterised in that said harvester device (9) comprises at least one second winding (19) made of electrically conductive material adapted to concatenate a magnetic field of said moving

10 magnetic element (11) sliding along said sliding guide (13) .

3. Ski- or trekking-racket (1) according to claim

2, characterised in that said first winding (17) and said second winding (19) are symmetrically

15. arranged with respect to the centre distance axis of said moving magnetic element (11) .

4. Ski- or trekking-racket (1) according to claim I, characterised in that said sliding guide (13) is at least one tubular recess longitudinally obtained 0 inside said stem (3) .

5. Ski- or trekking-racket (1) according to claim 1, characterised in that said harvester device is eguipped with connecting means in order to be connected to at least one electric apparatus to be 5 supplied with current.

6. Ski- or trekking-racket (1) according to claim 1, characterised in that it comprises at least one searching device (20), preferably an avalanche searching device (ARVA) , connected to said harvester device (9) and supplied with current by said harvester device (9).

7. Ski- or trekking-racket (1) according to any one of the previous claims, characterised in that it comprises managing means (21) for an operation of said harvester device (9).

8. Ski- or trekking-racket (1) according to claim

7, characterised in that said managing means (21) comprise at least one electronic recharging card eguipped, for every winding (17, 19), with at least one rectifying and levelling circuit composed of electric current rectifying means (23), electric current stabilising means (25) , means for accumulating electric energy, each one of said windings (17, 19) being connected to a respective rectifying and levelling circuit.

9. Ski- or trekking-racket (1) according to claim

8, characterised in that said rectifying means comprise at least one diode bridge.

10. Ski- or trekking-racket (1) according to claim 8, characterised in that said stabilising means comprise at least one level capacitor of the nonpolarised ceramic type.

11. Ski- or trekking-racket (1) according to claim 8, characterised in that said means for accumulating electric energy comprise at least one rechargeable backup battery.