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Title:
CONTACT DEVICE AND METHOD OF USING SAME
Document Type and Number:
WIPO Patent Application WO/2011/062501
Kind Code:
A1
Abstract:
There is described a contact device (1) and a method of using same to be able to transfer electrical energy from a stationary energy carrier (3) to a vehicle (5), where the contact device is connected with a portion of the vehicle (5), where the contact device (1) includes: - a support body (10) having a first end portion (12) and a second end portion (14), where the first end portion (12) is fastened to a portion of the vehicle (5); - a drum (24) rotatably connected to the second end portion (14) of the supporting body (10); and - multiple contact elements (26) projecting from the drum (24) and arranged to be able to be brought into contact with the stationary energy carrier (3) such that electrical energy may be led from the energy carrier (3) to a desired location in the vehicle (5). Also described is an energy carrier (3) for use together with the contact device (1).

Inventors:
AKSNES JON GUNNAR (NO)
Application Number:
NO2010/000409
Publication Date:
May 26, 2011
Filing Date:
November 11, 2010
Export Citation:
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Assignee:
AKSNES JON GUNNAR (NO)
International Classes:
B60L5/00; B60L5/42; H01R39/02
Domestic Patent References:
WO2000046065A12000-08-10
Foreign References:
FR2696985A11994-04-22
DE10216855A12003-11-06
US4476947A1984-10-16
Attorney, Agent or Firm:
HÅMSØ PATENTBYRÅ ANS (Sandnes, NO)
Download PDF:
Claims:
C l a i m s

A contact device (1) to be able to transfer electrical energy from a stationary energy carrier (3) to a vehicle (5) , the contact device (1) being connected with a portion of the vehicle (5) , the contact device (1) including: a support body (10) having a first end portion (12) and a second end portion (14) , where the first end portion (12) is attached to a portion of the vehicle (5) ; and a drum (24) rotatably connected to the second end portion (14) of the support body (10) , c ha r a c t e r i s e d i n that a plurality of contact elements (26) protrude from the drum (24) and are arranged to be able to be brought into contact with the stationary energy carrier (3) such that electrical energy may be led from the energy carrier (3) to a desired location in the vehicle (5) .

A contact device (1) according to claim 1, wherein the stationary energy carrier (3) is placed in connection with a surface carrying the vehicle (5) .

A contact device (1) according to claim 1, wherein a portion of the support body (10) is pivotally

connected to the vehicle (5) so that the distance from the drum (24) to the energy carrier (3) may be

adjusted to thereby be able to bring the contact elements (26) into or out of contact with the energy carrier (3) .

A contact device (1) according to claim 1, wherein each contact element (26) is constituted by an

elongated body that at least in one portion (25) is fastened to the drum (24) . A contact device (1) according to claim 4, wherein the elongated body (26) is loop-shaped.

A contact device (1) according to claim 5, wherein the loop-shape is provided by fastening at least one second portion (25') of the elongated body (26) to the drum (24) .

A contact device (1) according to claim 5, wherein the loop-shape is provided by fastening at least one second portion (25') of the elongated body (26) to a third portion of the body (26) .

A contact device (1) according to claim 5, wherein the loop-shape is provided by fastening at least one second portion (25') of the elongated body (26) to a portion of a neighbouring body (26) .

A contact device (1) according to claim 6, 7 or 8, wherein the one second portion (25') is fastened by means of one of the fastening methods : permanently fastened, releasably fastened, slidably fastened.

A method for transferring electrical energy from a stationary energy carrier (3) to a vehicle (5) , the energy being transferred from the energy carrier (3) to the vehicle (5) by means of a contact device (1) including a drum (24) protruding from a portion of the vehicle (5) and arranged to be able to rotate

corresponding to the motion of the vehicle (5)

relative to the energy carrier (3) ,

c h a r a c t e r i s e d i n that the method further comprising providing the drum (24) with a plurality of contact elements (26) being brought into contact with the stationary energy carrier (3) such that electrical energy is led from the energy carrier (3) to a desired location in the vehicle (5)..

Description:
CONTACT DEVICE AND METHOD OF USING SAME

The present invention relates to a contact device and a method of using same. More particularly it concerns a contact device to be able to transfer electrical energy from a stationary energy carrier to a vehicle, where the contact device is connected to a portion of the vehicle. The present invention is particularly directed toward vehicles with electric motor, such as a so-called el-car, or vehicles having a hydro generator.

The following description is particularly directed toward el- cars, but it is to be understood that the invention may be used in connection with any vehicle having a need for supply of electrical energy.

Due to environmental considerations there is a need for reduction of emissions from vehicles driven by combustion engines. Even if a modern combustion engine has considerably lower emissions than what combustion engines had some few years ago, the number of vehicles globally is increasing rapidly. There is therefore a need to increase the share of for example el-cars whose energy at least some places is produced from renewable sources.

The use of el-cars has per the year 2009 only a limited usage. The reasons for this limited use may be many, but a limited range, long charging time, relatively limited engine power and limited comfort is often brought forward as el -car drawbacks. Traditional charging requires that electrical energy is transferred to the vehicle by means of a cable. Thus the vehicle must be stationary while the charging is in progress .

Research is currently being carried out on so-called

induction charging, often called "wireless" charging.

Wireless charging makes charging possible both when the vehicle is moving and while it is stationary, and may thus be utilised, in such as crossroads where the traffic is often moving slowly, and in such as car parks.

One of the challenges of wireless charging is that very strong electromagnetic fields are formed during charging, and these may be unfavourable health-wise.

There is known from the toy industry so-called "car-tracks" where electrical cars are provided with sliding contacts transferring electrical energy from conductor rails to the electric motor of the car. The sliding contacts are bent relative to a certain direction of motion of the car and may thus not be used for moving the car in reverse. These types of sliding contacts are worn relatively quickly and have thus a relatively short distance of use.

From the publication US 4476947 is known an electric driven vehicle and a device for transfer of energy from electrically conducting bands positioned in a road surface to the vehicle. The vehicle is provided with an electrically conducting wheel that is put in contact with the band to transfer power to the vehicle .

From the publication FR 2696985 is known an electrical power transfer system for electric vehicles where electrical energy may be transferred from a stationary energy carrier to an electric vehicle via contact devices comprising a drum, where the contact devices are connected with a portion of the vehicle .

From the publication WO 00/46065 is known a transport system comprising en electric vehicle, where electrical energy is transferred from a stationary energy carrier in a road path. The stationary energy carrier may be formed as conducting plates or a network of conductors placed in the surface of the road.

The object of the invention is to remedy or reduce at least one of the disadvantages of the prior art, or at least to procure a useful alternative to the prior art.

The object is achieved, by the features disclosed in the below description and in the subsequent claims .

According to a first aspect of the present invention, there is provided a contact device to be able to transfer

electrical energy from a stationary energy carrier to a vehicle, the contact device being connected with a portion of the vehicle, the contact device including:

- a support body having a first end portion and a second end portion, where the first end portion is attached to a portion of the vehicle;

- a drum that is rotatably connected to the second end portion of the supporting body; and

- a plurality of conta.ct elements protruding from the drum and arranged to be able to be brought into contact with the stationary energy carrier such that electrical energy may be led from the energy carrier to a desired location in the vehicle .

The contact device according to the invention is thus a rotatable contact that in the following also will be termed rolling contact. A rolling contact has the advantage that it may be rotated in two directions and thus transfers

electrical energy to a vehicle independently of the direction of motion of the vehicle.

The stationary energy carrier may be placed in connection with a surface carrying the vehicle . The surface may

typically be a road or a car park. The surface will, for simplicity, be referred to as a road in the following.

For practical reasons only a limited portion of the roads may probably be provided with stationary energy carriers. The most relevant places are presumably in areas where the speed is low so that the retention period is as long as possible relative to the length of the energy carrier, in acceleration lanes and in so-called crawler lanes.

In order to avoid unnecessary wear on the contact elements of the contact device it is an advantage if the support body is pivotally connected to the vehicle so that the spacing between the drum and the energy carrier may be adjusted to thereby be able to bring the contact elements into or out of contact with the energy carrier. The distance is adjusted by means of per se known driving means such as, but not limited to, a motor, a mechanical and/or an electric means.

An elongated body that in at least one portion is fastened to the drum may constitute each contact element.

In order to obtain a largest possible contact surface between the energy carrier and ea.ch single contact element, it is an advantage if a longitudinal portion of the contact elements being rotated to abutment against the energy carrier, are bearing against it . When the vehicle is in motion, and the contact elements are contacting the stationary energy carrier, the drum will rotate and the contact elements will be exposed to

centrifugal forces.

In order to reduce a considerable increase in the diameter of the rolling contact due to the influence of the centrifugal forces on the contact elements, the elongated contact element may be loop-shaped.

The loop-shape will also be able to produce a resilient effect if the rolling contact is led over an object, such as a stone that might be on the energy carrier.

Fixing at least a second portion of the elongated body to the drum may provide the loop-shape. Thereby at least two

portions of the elongated body may be fastened to the drum.

The loop-shape may alternatively or in addition be provided by fastening at least one second portion of the elongated body to a third portion of the body or to a portion of a neighbouring body.

The second portion may be fastened by means of one of the fastening methods: permanently fastened, releasably fastened, slidably fastened. When the other portion is slidably

fastened it will in a preferred embodiment be arranged to be able to be moved inward toward the drum, but not further than a predetermined distance from the drum. A maximum diameter is thereby ensured at the same time as the rolling contact may be resilient in toward the centre of the drum.

In a second aspect of the present invention there is provided a method for transferring electrical energy from a stationary energy carrier to a vehicle, the energy being transferred from the energy carrier to the vehicle by means of a contact device including a drum protruding from a portion of the vehicle and arranged to be able to rotate corresponding to the movement of the vehicle relative to the energy carrier, the method further comprising providing the drum with a plurality of contact elements being brought into contact with the stationary energy carrier such that electrical energy is led from the energy carrier to a desired location in the vehicle .

Also described is an energy carrier for use together with a contact device according to the first aspect of invention, where the energy carrier is constituted by electrically conducting mats placed on a substrate on which a vehicle may be located.

The mats are located essentially parallel to and spa.ced such that each of the vehicle contact devices may bear against a mat each.

The power supply to the mat may be arranged to be

activated/deactivated by means of a sensor arrangement reacting on a relevant vehicle.

In the following is described an example of a preferred embodiment illustrated in the accompanying drawings, wherein:

Fig. 1 shows a perspective view of a vehicle located on and being in electrical contact with an energy carrier by means of a connecting device according to the present invention;

Fig. 2 shows in a larger scale a perspective view of an embodiment of a connection device;

Fig. 3 shows a principle sketch of an embodiment of a

connection device viewed in section from the side; Fig. 4 shows a principle sketch of an alternative

embodiment of the connection device shown in figure

3;

Fig. 5 shows a principle sketch of an alternative

embodiment of the connection device shown in figure

3/

Similar or equivalent elements are indicated by the same reference numerals in the figures.

In the figures the reference numeral 1 indicates a contact device, which is arranged to be able to transfer electrical energy from a stationary energy carrier in the form of an electrically conducting mat 3 shown in figure 1. The mat 3 is fixed to a road 4, e.g. by means of suitable fixation means and/or by integrating the mat 3 in the surfacing of the road

4.

The contact device 1 is located on the underside of a vehicle

5 in the following also being denoted an el-car 5.

A person skilled in the art will understand that the el-car 5 must be provided with two mutually spaced apart contact devices 1 each of which being able to be brought into contact with a corresponding one of two separate electrical mats of opposite polarities.

In the embodiment shown in figure 1 the mats 3 are supplied with power from an already existing street light 7. The current is transformed to the desired voltage by means of a converter 9 known per se known. Alternating current of 50 volt and at 1000Hz may for example be applicable.

By means of technology known per se, power may be supplied to the mat 3 only in those cases a control system (not shown) registers that an el-car 5 approaches or is located on the mat 3. The registration may for example be achieved by means of a technology based on radio frequency identification, so- called RFID-technology, arranged in the el-car 5 and in connection with the mat 3. The registration may also be connected with a payment system as is known from automatic toll road collection systems.

In figure 2 is shown in a larger scale a perspective view of one embodiment of a contact device 1.

The contact device 1 includes a supporting body 10 having a first end portion 12 and a second end portion 14.

The first end portion 12 is provided with two spaced apart fastening devices 16 that can be fastened to an underside of the vehicle 5. It is to be understood that the fastening- devices 16 are electrically insulated from the vehicle.

Two supporting arms 20 extend from a rod-shaped supporting body 18 being pivotally connected to the fastening devices 16.

The supporting body 18 may be pivoted relative to the fastening devices 16 by means of per se known means (not shown) .

The supporting arms 20 are in the second end portion 14 of the supporting body 10 rotatably connected to a drum 24.

The drum 24 is provided with a plurality of elongated, electrically conducting contact elements 26, which in a first end portion 25 are connected to the drum 24 and protruding out from holes (not shown) in the shell of the drum 24. In an alternative embodiment (not shown) the contact elements may be fastened to the shell of the drum. Current is thus led from the mat 3 via the contact elements 26, drum 24, supporting arms 20, and the fastening devices 16, and from these further through not shown cables to a desired place in the vehicle 5. The desired place may be such as the battery or an electric motor.

By rotating the rod-shaped support body 18 and thus the supporting arms 20 relative to the fastening devices 16, the drum 24 and the contact elements 26 may selectively be brought into or out of contact with the mat 3. The contact device 1 may thus only be brought into contact with the substrate only when heeded. The wear on the contact device 1 will thus be greatly reduced.

In the embodiment shown in figure 2 and figure 3 each of the contact elements 26 has a helix like shape and, as shown in figure 3 are provided with a hook 27 in a second end portion 25' .

Figure 3 only shows four of the great number of contact elements 26 shown in figure 2.

The purpose of the hook 27 is that the second end portion 25' shall hook on to a portion of another but nearby contact element 26. Said portion is located between the first end- portion 25 and the second end portion 25' of the contact element 26.

By hooking a second end portion 25' of a contact element 26 on to a portion of for example a neighbouring contact element 26, the second end portion 25' will be held back against the movement away from the centre of the drum 24 due to the centrifugal forces arising from the rotation of the drum 24.

Being able to resist movement due to centrifugal forces has the great advantage that the contact elements 26 may be formed with the largest possible diameter being relatively- little influenced by the centrifugal forces acting on the contact elements when the drum 26 is rotated. Thereby the contact elements 26 will to the largest possible extent maintain their shape independently of the rotational speed of the drum 24. At the same time the contact elements 26 may be bent or be resilient inwards toward the drum 24 if a body protrudes from a portion of the mat 3. Such a body may be such as a stone or some other foreign object being on the mat 3.

The rotating part of the contact device 1 constituted by the drum 24 with the appurtenant contact elements 26, have thus an essentially constant maximum diameter at the same time as every one of the multiple contact elements 26 is resilient. The electrical contact between the mat 3 and the vehicle 5 may be maintained by some of the contact elements 26 at the same time as others of the contact elements 26 are brought out of electrical contact as a consequence of a possible foreign object being on the mat 3.

The resilient property of the contact elements 26 will also be important to provide the largest possible contact surface against the mat 3. By letting the contact device 1 exercise a certain pressure against the substrate, the resilient

property of the contact elements 26 will result in a larger contact surface by the very fact that a larger portion of every single contact element 26 will bear ajainst the mat 3.

The contact elements 26 may be arranged in several ways on the drum 24 to achieve the above, important property.

Each of the end portions 25, 25' of every single contact element 26 may for example be fastened to the drum 24. This is shown in figure 4. The contact element 26 will thus be able to form a loop protruding from the drum 24. For clarity only two of a large number of contact elements 26 are shown.

A support element 28 may protrude from a top portion of the loop in toward the drum 24 and be fastened to a portion of this or to a portion of the contact element 26. Both

alternatives are shown in figure 4.

In the embodiment shown the support element 28 co-operate in providing a relatively flat or extended contact surface between the contact element 26 and the mat 3. Each loop may be provided with more than one or less than the one support element 28 shown.

Figure 5 shows another, alternative embodiment of the contact elements 26. In the example shown each of the contact

elements 26 (only three shown) protrude essentially

perpendicularly outward from the drum 24. The contact element 26 is in its second end portion 25' formed with an angle to form a sufficiently large contact surface with the mat 3.

To reduce the effect of the centrifugal forces arising when the drum 24 and thereby the contact elements, are set in rotation, the angular portion is supported by a supporting element 28.

The supporting elements 28 shown in figures 4 and 5 may, but not necessarily, be electrically conducting.

In the figures 3, 4 and 5 the drum 24 is shown with a core portion 24' being enclosed by an external casing portion 24' ' .

Between the core portion 24' and the casing portion 24'' is an annulus 29 arranged to be able to house and keep fastened the end portions of the contact elements 26 that are led through holes in the casing portion 24''.

In one embodiment the core portion 24' is put into the casing portion 24'' after the contact elements 26 are placed in the casing portion 24''. Centring of the core portion 24' into the casing portion 24'' may be provided by means of not shown centring elements .

It is to be understood that in an alternative embodiment (not shown) the contact elements 26 may be constituted by one or more elongated bodies that are alternately threaded in and out through holes in the casing portion 24''.

From the above description it will be understood that the present invention provides a contact device which, opposed to hitherto known sliding contacts, will be able to transfer electrical energy from en energy carrier to a vehicle

independently of the vehicle moving forward or in reverse, or being stationary.

The contact device according to the invention will exhibit a resilient effect in passing over objects being on the surface of the energy carrier, at the same time as the maximum diameter of the contact device is essentially constant and independent of the speed of the vehicle. The rolling motion of the contact device against the energy carrier will

moreover reduce wear on both the contact device and the energy carrier.

By locating the energy carrier in places where a vehicle is parked or moving slowly, and/or in places where the vehicle energy need is relatively large such as in an accelerating lane and in long uphills, the range of the vehicle may be increased considerably.