Magnetic wheel

Abstract

Magnetic circuit that has (a) a source of magnetic flux which includes an electromagnet or one or more permanent magnets, (b) at least two oppositely polarisable pole extension bodies associated with the magnetic flux source, the bodies being disc, wheel, roller or similarly shaped with an outer circumferential surface and held rotatable about respective axes of rotation, and (c) a ferromagnetic counter body which is arranged to cooperate with the pole extension bodies such as to provide an external flux path for the magnetic flux when in magnetic proximity or contact with the circumferential surface of the pole extension bodies, which is characterised in that the magnetic flux source is held stationary relative to the rotatable pole extension bodies.

1 . Magnetic circuit having (a) one or more permanent magnets as a source of magnetic flux, (b) at least two oppositely polarisable pole extension bodies associated with the magnetic flux source, the bodies being disc, wheel, roller or similarly shaped with an outer circumferential surface and held rotatable about respective axes of rotation, and (c) a counter body having ferromagnetic properties which is arranged to cooperate with the rotatable pole extension bodies in providing an external flux path for the magnetic flux when in magnetic contact with the circumferential surface of the pole extension bodies, the magnetic flux source being held stationary relative to the rotatable pole extension bodies. 
   
   
       2 . Vehicle capable of magnetically attaching to a magnetically attractive substrate, including a vehicle body at which are supported at least two wheel members and at least one magnet exhibiting a N— and a S-pole, wherein the wheel members include magnetically passive but polarisable material, wherein the wheel members and the magnet(s) are spatially located on the vehicle body in a manner wherein the wheel members provide rotatable, oppositely polarisable pole extension elements of the N— and S-poles of the otherwise stationary magnet(s), whereby resting of the wheel members on the surface of a magnetically attractive substrate creates a closed magnetic circuit encompassing the magnet, pole extension wheel members and the substrate. 
   
   
       3 . Support appliance capable of magnetically retaining attached to it in an otherwise displaceable manner a magnetically attractive body, including a support structure at which are mounted at least two wheel or roller members arranged for rotation about respective axes, and at least one magnet exhibiting a N— and S-pole mounted at the support body separate from the wheel or roller members, wherein the wheel members include magnetically passive but polarisable material, and wherein the wheel or roller members are spatially located on the support structure in a manner wherein the wheel members provide rotatable, oppositely polarisable pole extension elements of the N— and S-poles of the otherwise stationary dipole magnet, whereby bringing a magnetically attractive substrate into surface contact with the peripheral surface of the wheel members creates a closed magnetic circuit encompassing the magnet, pole wheel or roller members and the substrate. 
   
   
       4 . Vehicle according to  claim 2 , respectively, wherein the at least one magnet is supported such as to maintain an air gap to the wheel or roller pole extension members. 
   
   
       5 . Appliance according to  claim 3 , respectively, further including drive means arranged for transferring torque into at least one of the wheel or roller members. 
   
   
       6 . Vehicle according to  claim 2 , further including means for self-propelling the vehicle on the substrate surface. 
   
   
       7 . Vehicle according to  claim 6 , wherein the self-propelling means include an arrangement for transferring torque to at least one of the wheel members from an on-board motor. 
   
   
       8 . Appliance according to  claim 5 , wherein the drive means include one of a belt drive, a sprocket wheel drive, a chain drive or a worm gear drive or combinations thereof. 
   
   
       9 . Appliance according to  claim 8 , wherein the drive means include one or more friction rollers disposed to transmit or receive torque by engagement with an outer circumference of at least one of the wheel members. 
   
   
       10 . Appliance according to  claim 9 , wherein the friction rollers incorporate ferromagnetic materials operatively arranged for biasing the rollers into and holding contact with the wheel member(s) through magnetic force. 
   
   
       11 . Vehicle or appliance according to  claim 8 , wherein the drive means include a gear box or arrangement. 
   
   
       12 . Appliance according to  claim 3 , respectively, wherein one dipole magnet is provided per wheel or roller member pair. 
   
   
       13 . Appliance according to  claim 12 , wherein the dipole magnet is a switchable permanent magnet device arranged for generating an external magnetic field that can be varied between a maximum flux density output in a fully on or active state and a minimum, practically negligible flux density output in a fully off or deactivated state. 
   
   
       14 . Appliance according to  claim 13 , wherein the switchable permanent magnet device includes one of a toggle switch for changing and selecting between fully on and fully off states and an incremental switch for setting and fixing a magnetic flux output between fully on and fully off. 
   
   
       15 . Appliance according to  claim 12 , wherein the wheel or roller members are cup shaped in cross-section, and wherein the dipole magnet extends with one of its poles into the cup shaped wheel or roller. 
   
   
       16 . Appliance according to  claim 13 , having at least four of said wheels or rollers arranged in pairs, wherein one said switchable permanent magnet device is present per each said wheel or roller member pair, and further including a device for discretely switching the two switchable permanent magnet devices independently or jointly. 
   
   
       17 . Magnetic circuit according to  claim 1 , wherein the rotatable pole extension bodies are wheel shaped and have a cross-sectional shape and dimensions to (a) minimise flux transfer losses from the magnetic flux source into the rotatable pole wheels, (b) provide relatively larger area virtual poles thereby to maximise flux transfer outside of the direct physical contact zone between pole extension wheels and substrate surface, and (c) maintain a predetermined value of magnetic attraction force towards the substrate. 
   
   
       18 . Magnetic circuit according to  claim 17 , wherein the pole extension wheels are cylindrically cup-shaped bodies having an annular flange portion having an axial length which is a function of the magnetic field strength of the magnetic flux source. 
   
   
       19 . Magnetic circuit according to  claim 18 , wherein the cup-shaped pole extension wheels have an axial length sufficient to cover the magnetic flux source to an extent where the flux source exhibits approx 70% of its maximum field strength. 
   
   
       20 . Magnetic circuit according to  claim 1 , wherein the magnetic flux source comprises switchable permanent magnet devices switchable to exhibit an external magnet field between strong and weak (practically zero) values.