Eddy current braking apparatus with adjustable braking force

Abstract

An eddy current brake includes a diamagnetic member, a first support wall and a second support wall with the first and second linear arrays of permanent magnets disposed on the walls facing one another. Apparatus is provided for moving at least one of the walls in order to control eddy current induced in the member in the passage of the member therepast to adjust the braking force between the magnets and the member. Apparatus is also provided for causing the velocity of the member to change the braking force between the magnets and the member.

Description

The present invention is generally related to permanent magnet linear brakes and is more particularly directed to an eddy current brake and magnet system for providing adjustable braking for movable apparatus, for example, rail support moving apparatus, go-cart moving apparatus, elevator moving apparatus, conveyer moving apparatus, roller coaster moving apparatus, and magnetically levitated vehicles or apparatus, among others.

Heretofore, eddy current braking system for providing deceleration of moving apparatus have utilized physically fixed magnets which provided no opportunity to adjust braking before or during passage of a diamagnetic member past a linear array of permanent magnets.

Accordingly, such prior art systems, when installed for decelerating a plurality of moving apparatus, cannot accommodate for variations in apparatus weight, speed, and size.

The present invention provides for a unique permanent magnet array arrangement and apparatus for adjusting braking force before and/or during passage of apparatus, such as, for example, a car past a selected point.

SUMMARY OF THE INVENTION

An eddy current brake in accordance with the present invention generally includes a diamagnetic or non-magnetic member, a first support structure and a separate second support structure disposed in a spaced apart relationship with the first support structure for enabling the member to pass therebetween.

A first linear array of permanent magnets is disposed on the first structure on the side facing the second structure and a second linear array of permanent magnets is disposed on the second structure on the side facing the first structure. The first and second arrays are parallel with one another and spaced apart from one another for allowing passage of the member therebetween and causing eddy current to be induced in the member which results in the braking force between the magnets and the member. No magnetic connection, such as a yoke, is required between the structures or the arrays of permanent magnets. This feature enables adjustability of the distance between the member and the magnet arrays.

In accordance with the present invention, apparatus is provided for moving a least one of the first and second structures in order to control eddy current induced in the member during the passage of the member therepast in order to adjust braking force between the magnets and the member. In one embodiment of the present invention, the apparatus includes means for moving at least one of the first and second structures in a direction perpendicular to the member, and in another embodiment of the present invention, the apparatus includes means for moving at least one of the first and second walls in a direction parallel to the member.

Thus, it can be seen that the apparatus in accordance with the present invention provides for changing the spaced apart relationship between the first and second structures in order to control eddy current induced in the member during passage and adjust a braking force between the magnets and member.

Accordingly, the amount of deceleration provided to a given moving apparatus may be adjusted in accordance with the present invention. In addition, moving apparatuses of various sizes, weights, and speeds may be utilized and the eddy current magnetic brake in accordance with the present invention adjusted to provide the proper, or desired, deceleration. In one embodiment to the present invention, apparatus is provided for adjusting the eddy current induced in the member, and the braking force, as a function of velocity of the member between the arrays. Thus, moving apparatuses having various velocities upon passing the brake, can be decelerated to a more uniform velocity exiting the brake in accordance with the present invention.

In this embodiment of the brake, the apparatus for adjusting eddy current includes a linkage mounting at least one of the first and second structures to a fixed foundation for enabling movement of the member therepast to change a distance between at least one of the first and second structures and the member. More particularly, the linkage may provide for changing a spaced apart relationship between the first and second structures.

An embodiment of the present invention includes linkage for enabling movement of the member to change a transverse relationship between at least one of the first and second structures of the member and another embodiment provides linkage for enabling movement of the member to change a parallel relationship between the first and second structures and the member.

Magnetic coupling and inducement of eddy current is effective through a linear array of permanent magnets which may include a container and plurality of magnets disposed therein. The magnets may be arranged within the container in at least two adjacent rows with each magnet in each row being arranged with a magnetic field at a 90° angle to adjacent magnets in each row along the container. Each magnet in each row is also arranged with a magnetic field at an angle to another adjacent magnet in the adjacent row.

In yet another embodiment of the present invention an eddy current brake includes a diamagnetic or non-magnetic member with a fixed linear array of permanent magnets. A moveable linear array of permanent magnets is disposed in a parallel relationship with the fixed linear array of permanent magnets for enabling passage of the member therebetween.

Apparatus is provided for adjusting the eddy current induced in the member, and concomitant braking force, by the lateral movement of the movable linear array of permanent magnets.

More specifically, this embodiment may utilize an actuator disposed in an operational relationship with a movable linear array of permanent magnets or alternatively utilize a spring or similar force mechanism, attached to the movable linear array of permanent magnets for enabling the lateral movement of the movable array as a function of velocity of the member between the magnetic arrays. In this way the braking force is automatically adjusted upon relative velocity between the member and the magnet arrays.

Still another embodiment of the present invention includes an eddy current brake with a diamagnetic or non-magnetic member, at least two arrays of permanent magnets and at least one rotatable array of permanent magnets disposed in a spaced apart relationship with the fixed array of permanent magnets for enabling the passage of the movement therebetween.

Apparatus is provided for adjusting the eddy current induced in the member, and concomitant braking force, through rotation of the rotatable arrays of permanent magnets. More specifically, the apparatus may include an actuator disposed in an operational relationship with the rotatable array of permanent magnets for rotation thereof. Alternatively, a spring may be attached to a rotatable array of permanent magnets for enabling rotation of the rotatable array as a function of velocity of the member between the magnetic arrays. Again, this configuration provides for automatic adjustment of braking force as a function of member velocity.

A further embodiment of the present invention includes an eddy current brake mechanism with a diamagnetic of non-magnetic member, a first movable linear array of permanent magnets and a second movable linear array of permanent magnets disposed in a spaced apart parallel relationship with the first array for enabling passage of the member between and within a plane established by the parallel arrays.

An actuator may be provided and connected to the arrays for adjusting the eddy current induced in the member, and concomitant braking force, through movement of the arrays in a direction perpendicular to the plane.

Yet another embodiment of the present invention provides for an eddy current braking mechanism for a moving apparatus having spaced apart wheels for engagement with a pair of parallel rails. The mechanism includes a diamagnetic or non-magnetic member descending from the moving apparatus between the wheels and first and second linear arrays of permanent magnets disposed in a parallel spaced apart relationship for enabling passage of the member therebetween in order to induce eddy current, and concomitant braking force, in the member upon passage of the member between the arrays.

Springs disposed between the moving apparatus and each wheel are provided for enabling lowering of the member between the arrays as a function of moving apparatus weight thereby adjusting the induced eddy current and braking force as a function of moving apparatus weight.

BRIEF DESCRIPTION OF THE DRAWINGS

The advantages and features of the present invention will be better understood by the following description when considered in conjunction with the accompanying drawings in which:

FIG. 1 is a perspective view of an eddy current brake in accordance with the present invention generally showing first and second spaced apart support structures and first and second linear arrays of permanent magnets along with a diamagnetic or non-magnetic member attached to moving apparatus such as a moving apparatus, represented by dashed line, and a sensor for determining member velocity;

FIG. 2 is a perspective view of a first linear array of permanent magnets disposed upon a first support structure;

FIG. 3 is an elevational view of the brake shown in FIG. 1;

FIG. 4 shows a selectively actuatable brake system disengaged;

FIG. 5 shows a system of FIG. 8 engaged, it should be appreciated that either the member or the array(s), or both, may be selectively actuated;

FIG. 6 is an elevational view of an alternative embodiment according with the present invention further showing apparatus for moving at least one of the first and second structures in order to control the distance between permanent magnets and opposing structures for adjusting braking force between the magnets and a member;

FIG. 7 is plan view of the brake shown in FIG. 6;

FIG. 8 is an enlarged view of a linear array of permanent magnets in accordance with the present invention generally including a channel and a plurality of magnets disposed therein in a particular arrangement as will be hereinafter described in greater detail;

FIGS. 9 and 10 show embodiment of the present invention similar to that shown in FIGS. 8 and 9 and further including apparatus for adjusting eddy current induced and in the member, and braking force, is a function of velocity of the member between arrays of magnets;

FIGS. 11-14 are diagrams of alternative embodiments of the present invention which provide for linkage from at least one of the first and second structures to a fixed foundation for enabling movement of the member past the first and second structures with the first and second magnet arrays thereon to change a perpendicular relationship between the first and second structures and the member;

FIGS. 15 and 16 are diagrams of an eddy current brake mechanisms with a fixed linear array of permanent magnets, a movable linear array of permanent magnets and apparatus for adjusting eddy current induced in the member by longitudinal movement of the movable linear array of permanent magnets;

FIGS. 15A and 16A are diagrams of an alternative embodiment of an eddy current brake mechanism with a fixed linear array of permanent magnets, a movable linear array of permanent magnets and apparatus for adjusting eddy current induced in the member by longitudinal movement of the movable linear array of permanent magnets;

FIG. 17 is a diagram of eddy current mechanism utilizing a fixed array of permanent magnets and at least one rotatable array of permanent magnets and an apparatus for adjusting eddy current induced in a member passing therebetween through rotation of the rotatable array of permanent magnets;

FIG. 18 is a diagram of eddy current brake mechanism showing two movable linear arrays (shown in a more graphic representation in FIGS. 4 and 5) of permanent magnets and an actuator for adjusting eddy current induced in a member passing therebetween by movement of the arrays in a direction perpendicular to a plane established by the arrays of magnets; and it should be appreciated that either the member or the array(s), or both, may be selectively actuated.

FIG. 19 is a diagram of an eddy current brake mechanism utilizing fixed magnet arrays and a spring arrangement between a moving apparatus and wheels for lowering a member attached thereto in a depending fashion as a function of a moving apparatus weight in order to adjust the induced eddy current in the member as the member passes between the magnet arrays.

DETAILED DESCRIPTION

For the ensuing description of a braking apparatus 10 for an object 12, reference is made particularly to FIGS. 1-3. The object 12 is shown in generalized form only and is contemplated for movement, or travel, in the direction of the arrow 15. Affixed to the object 12 is a member, or fin, 14 which extends outwardly from the object 12 and also moves with the object in the direction of arrow 15.

At some point along the path of movement there are mounted first and second laterally spaced magnet arrays 16 and 18. Each array includes an elongated support structure 20 which may be any cross-section, such as, for example an L-shaped cross-section, and on a lateral surface thereof, there are provided a linear series of permanent magnets 22, of any size, arrangement or configuration. For instance, the magnets may alternate in polarity as indicated by the identification letters “S” and “N”. Also, the space 26 between the arrays is dimensioned and arranged with respect to the object path of movement, that the fin 14 will move along the space directly opposite the magnets and spacers, but remain out of physical contact with either the magnets or spacers.

When the fin 14 passes through the magnetic field existing in the space 26, an electric current (eddy current) is induced in the fin 14 which, in this case, reverses as the fin passes from a magnet of one polarity to a magnet of opposite polarity. These eddy currents produce a force exerted on the fin 14 (and object 12) of such direction as to reduce the velocity of movement of object 12 and fin 14. It is this deceleration that produces the “braking” of the present invention.

Although the above-described first embodiment includes movement of the object and fin past fixedly located magnet arrays, the magnet arrays can just as well be moved past a stationary object and fin. All that is needed to achieve the braking effect is relative movement between the magnets and fin. Since usually the object is moving, in that case the magnet arrays would be carried by the object and the fin fixedly mounted adjacent the path of movement. The choice of which technique to employ depends upon the particular application.

In its more general aspects, the invention can be advantageously employed for braking a large variety of moving objects. As an excellent example, eddy current braking for elevators could be highly advantageous as an emergency measure where normal operation has somehow been interfered with or disrupted. Also, many amusement park rides could benefit by having eddy current braking devices to retard excessive speed as the “ride” vehicle takes a corner or drops at a severe angle.

FIGS. 4 and 5 illustrate an object 52 with a brake fin 54 interconnected therewith, that moves generally along a direction indicated by an arrow 56 which normally will pass by a magnet 22 (FIG. 2) moving apparatus 58 beyond the range of substantial magnetic interaction (FIG. 4). Relative movement between the fin 54 and magnets 22, indicated by the arrow 60, caused by the apparatus 58 effects magnetic coupling to achieve desired braking.

Alternatively, an actuator 62 may be carried by the object 52 for extending and retracts the fin 54, such actuator 62 may be of any suitable pneumatic or electric type.

A suitable velocity sensor 66 may be fixed to the support structure 18.

Although the above-described first embodiment includes movement of the object and/or the fin 54 past fixedly located magnet 22 arrays, the magnet 22 arrays can just as well be moved past a toward the object and fin 54 shown in FIG. 5. All that is needed to achieve the braking effect is relative movement between the magnets and fin. Since usually the object is moving, in that case the magnet arrays would be on the moving apparatus and the fin fixedly mounted adjacent the path of movement. The choice of which technique to employ depends upon the particular application.

With reference to FIGS. 6 and 7, there is shown an alternate embodiment 100 of the eddy current brake in accordance with the present invention generally including a diamagnetic or non-magnetic member 102, a first support structure 104 and a second support structure 106. Structures 104, 106 are separate from one another and disposed in a spaced apart relationship upon a base or foundation 110 via leg portions 112, 114 respectively. The spaced apart relationship enables the member 102 to pass between the structures 104, 106 and because 104, 106 are not fixed with respect to one another, a distance D therebetween can be adjusted as will be hereinafter discussed in greater detail.

A first linear array 120 of permanent magnets 122, see FIG. 8, is disposed on the first on a side 124 facing the second structure 106.

A second linear array 130 of permanents (not individually shown) are disposed on the second structure 106 on a side 132 facing the first structure 104 with the first and second arrays 120, 130 being parallel with one another as shown in FIG. 10. Apparatus 140, 142 is provided for moving the structures 104, 106 and change the spaced apart relationship between the first and second structures 104, 106 in order to control, or adjust, eddy current induced in the member 102 during passage of the member 102 past and between the structures 104, 106 and magnets 120, 130 thereby adjusting the braking force between the magnets arrays 120, 130 and the member 102. Either or both of the arrays 120, 130 may be moved to effect the change in braking force.

The apparatus 140, 142 may include adjusting nuts 144, 146 and bolts 148A, 148B, 150A, 150B interconnected between the structures 104, 106 and brackets 152, 154 fixed to the base 110.

Jam nuts 156, 158 prevent unwanted movement of the adjusting nuts 144, 146 and securing bolts 160, 162 extending through the base 110 and legs 112, 114 through slots 166, 168, fix the structures 104, 106 in a desired spaced apart relationship after adjustment. The exact size of the structures 104, 106, magnet arrays 120, 130, member 102 and spacing D will be dependant upon velocity and weight of a car (not shown) attached to the member 102 and may be empirically determined.

It should be appreciated that the apparatus 140, 142 may include any number of configurations for adjustment of the structures 104, 106. Such alternatives including single direction bolts, worm screws, jack screws, short in-line turn buckles, or other magnetic, electrical, pneumatic, hydraulic configurations capable of providing the adjustment of spacing D, between the structures 104, 106. Such configurations may eliminate a need for the securing bolts 160 and 162.

Although the above-described first embodiment includes two parallel magnet arrays 120, 130, it can just as well be configured with only one magnet array interacting fin. All that is needed to achieve the braking effect is relative movement between the magnets and fin. Since usually the object is moving, in that case the magnet arrays would be moving apparatus by the object and the fin fixedly mounted adjacent the path of movement. The choice of which technique to employ depends upon the particular application.

Preferably, each magnet array 120, 130, as illustrated by the array 120 in FIG. 7, includes at least 1 row 170, each having individual magnets 180, 182, 184, 186. A second row 172 may include individual magnets 188, 190, 192, 194 respectively.

The magnet rows 170, 172 may be disposed in a tube, or container 200 extruded shape or any form which may be formed of any suitable material such as aluminum, stainless steel, plastic; any number of magnets (not all shown) may be used.

The magnets 180, 194 are specifically arranged within the container 200 with a specific magnetic field pattern. While two rows 170, 172 are shown, it should be appreciated that any suitable number of rows (not shown) may be utilized.

The container 200 may be removably attached in any suitable manner to the wall 104. Thus, as hereinabove noted, assembly of the brake 100 is facilitated. Another advantage of the preassembly of magnets 180-186 is the is the fact that alternative magnet configurations may be easily exchanged on the wall 104 in order to tailor magnetic braking characteristics.

As heretofor noted, eddy current braking systems in accordance with the present invention for providing deceleration of moving apparatus may utilize alternating magnet polarities, reference is made particularly to FIGS. 1 and 2.

More particularly, a magnet 182 in a row 170 may be arranged with a magnetic field (indicated by the arrow 204) which is at an angle to the magnetic fields 206, 208 of adjacent magnets 180, 184 in the row 170. A number of angular relationship between the adjacent magnets 180, 182, 184 such as, for example, 15°, 30°, 45° or 90°. When the angular relationship between adjacent magnet 180, 182, 184 is 900, they may also be arranged with the magnetic field 104 at a 90° angle to a magnetic field 210 of the magnet 190 in the adjacent row 172. Such a 90° arrangement is called the Halbach Array.

When the angular relationship between adjacent magnets is other than 90°, such an arrangement shall be referred to as a Halbach variation.

An embodiment of the present invention includes the multiple row array of FIG. 8, which can be defined as array 120 or 130 of FIG. 6. When the Halbach array (90° alignment) or variations thereof (15°, 30°, 45° etc.) are employed in the multiple rows, the resulting magnetic field strength in space D, FIG. 6, is greater than the sum of the two individual rows 170 and 172. Multiples of 1.5 for two rows can be achieved, accomplishing a significant improvement in magnetic field strength per unit weight of magnet. This improvement subsequently produces high braking forces and represents an advancement over prior art systems.

Preferably, the magnets 180-194 are epoxied or otherwise potted into the container 200 and thereafter may be attached to the structure 104 in any suitable manner. Also, the container 200 may be open, as shown, or closed, (not shown) and be of any suitable shape for containing the magnets. Because the magnets may be assembled in the container 200 before installation on the structure 104, 106, assembly of the brake 100 is facilitated. In addition, change of magnetic field can be easily performed by changing of containers (not shown) having different magnet configurations therein.

The multi-row Halbach arrangement as shown in FIG. 8, can be built with no backiron. The advantage is that most of the flux is confined to the member of fin 102 area, without needing backiron as is needed in the standard eddy current brake (not shown). The flux is concentrated between the magnet array and is small above and below the magnets. Significant weight improvements result because no backiron is used.

Multiple rows 170, 172 in proper alignment permit the use of the cubic Halbach arrangement in such a way that brakes of increasing power levels can be constructed while maintaining a fixed depth of magnet.

The Halbach array can achieve higher braking forces for the equivalent volume of magnetic material of a conventional ECB. The Halbach array reduces stray magnetic field through the lower strength side of the array.

With reference to the diagrams shown in FIGS. 9 and 10, apparatus 250 including links 252, 254 interconnecting the structure 104 with a foundation 258 provides for changing, controlling, or adjusting eddy current induced in the member 102, and braking force, as a function of member 102 velocity between the structures 104, 106 and arrays 120, 130. Only one structure 104 is shown in FIGS. 9 and 10 for the sake of clarity.

As shown by the directional arrows 260, 262 in FIGS. 9 and 10 respectively, movement of the member 102 past the structure 104 and array 120 attached thereto provides a reaction force as shown by the arrow 266 which raises the structure 104 from stops 270, 272 in order to change a transverse relationship between the structure 104 and array 120 and the member 102. This transverse movement raises 104 increasing relative penetration of 102, into the magnetic field, which increases the induced eddy currents and braking action.

Because the drag force is a function of velocity, when the structures 104 are mounted for pivoting on the links 252, 254, the structure 104 is raised a specific height based upon the drag force generated causing rotation of the links 250, 254. Thus, the penetration of the member 102 into the magnetic flux established by the arrays 120, 130 is self regulated.

When used in one orientation, as shown in FIGS. 9, 10, the member 102 having a velocity in excess in a predetermined value would generate drag forces 266 sufficient to rotate, or pivot, the structure 104 to increase member 102 penetration and subsequently generating higher drag forces to reduce the excess velocity. As the velocity falls below the level necessary to generate drag force sufficient to fully rotate the structure 104 and pivot linkages 252, 254, the structure 104 rotates back toward the default position. How far back it rotates is a self regulating function of the velocity/drag force in that instance.

Thus, the apparatus 250 can be utilized as an automatic “trim” brake actuating only when necessary and only with a force necessary to maintain the desired velocity of the member 102 and vehicle attached (not shown). Opposite linkages (not shown) would have the effect of lowering the structure 102 upon movement of the member 102 therepast, thereby having the effect of flattening the initial drag peak and providing flatter more uniform deceleration.

As diagramed in FIGS. 11 and 12, apparatus 280 including pivoting links 282, 284, 286, 288 interconnected between a foundation 290 and the structures 104, 106 enable movement of the member as indicated by the arrow 302 to pivot the links 282, 284, 286, 288 in direction indicated by the arrows 304, 306 in order to change a distance d, between the structures 104, 106. The magnet arrays are not shown in FIGS. 11 and 12 for the sake of clarity in describing structures 104, 106 movement. Since the structures 104, 106 carry the magnet arrays 120, 130 the distance between the arrays 120, 130 is also varied. The links 282, 284, 286, 288 may include spring loaded pivots 310, 312, 314, 316 respectively in order to bias the structures 104, 106 against stops 320, 322 in a rest position.

As shown in FIG. 12, movement of the member between the structures 104, 106 decreases the distance d₁ to d₂, thus increasing magnetic flux the induced eddy currents and increasing a braking action. A stop 326 defines the minimum distance d₂ of approach between the structures 104, 106.

Similar linkage apparatus is shown in FIGS. 13 and 14 in connection with the structures 104, 106 and member 102. In this instance, links 342, 344, 346, 348 are interconnected so that movement indicated by the arrow 360 of the member 102 causes a spread or widening as indicated by the arrows 364, 366 of the structures 104, 106. Stops 370, 372, 376 limit the movement of the structures 104, 106 in a manner similar to that described in connection with the apparatus 280 shown in FIGS. 11, 12.

Spring loaded pivots keep the structures 104, 106 initially biased against the stop 376. This configuration lowers the magnetic coupling due to movement of the member 102 between the structures 104, 106 and, as hereinabove noted, has the effect of flattening the initial drag peak and provide a flatter more uniform deceleration. It should be appreciated that other means of opening and closing arrays and lowering the structures 104, 106 may be utilized which can include other mechanical, pneumatic, hydraulic or other components (not shown) to provide the same function.

With reference to FIGS. 15 and 16, there is diagramed an eddy current brake mechanism, which includes a diamagnetic or non-magnetic member 402, as hereinbefore described for movement between a fixed linear array 404 of permanent magnets 406 and a moveable linear array 408 of permanent magnets 410 which may be mounted on a rail 412, for longitudinal movement therealong. The longitudinal movement may be provided by, for example, magnetic attraction/repulsion, a pneumatic actuator, or electric motor 414 or, as shown in FIGS. 15A and 16A, a spring 416 which provides for automatic adjustment of eddy current induced in the member 402 between the arrays 404, 408. Common reference characters shown in FIGS. 15, 16, 15A, 16A refers to identical or substantially similar elements.

As illustrated in FIG. 15, the arrays 404 and 408 are positioned for optimum braking position with flux lines 420 represented in dashed format. That is, maximum braking force is achieved with the magnet arrays aligned as shown in FIG. 15.

As illustrated in FIG. 16, the actuator 414 has moved the movable array 408 by M wavelength, i.e. Δx=λ/2 and hence the flux 422 on the member 402 is minimized and accordingly braking force is minimized. While the permanent magnet arrays 404, 408 are shown as Halbach arrays, it should be appreciated that other magnetic arrangement of permanent magnets with or without backiron, or electromagnets may be utilized in accordance with the principle of the present invention.

When the spring 416 is utilized, no external motor or actuator of any kind is necessary. In this embodiment, the magnet array 408 is held in place by a spring, which offsets the force of the magnetic attraction to the adjacent magnet array 406.

It should be appreciated that the spring 416 may be interchanged for any number of configuration for offsetting the force of the magnetic attraction of adjacent magnet arrays.

When the member 406 moves between the arrays 404, 408 the electrodynamic braking force moves the movable array 408 to a more optimal braking position by dragging it by the effects of eddy currents.

At a higher speed of the member 402, there is more drag force acting on the movable array 408 and hence more force tending to move it to an optimal braking location, i.e. greater braking force. In this manner, the brake compensates for higher input speed of the member 402 by providing more braking force.

With reference to FIGS. 15-16 a velocity sensor 430 interconnected to the actuator 414 provides movement of array 408 in a longitudinal or parallel manner with respect to the array 404 as a function of velocity of the member 402 between the magnet arrays 404, 408.

With reference to FIG. 17, (an elevation view looking in the direction of travel), there is diagramed an eddy current brake mechanism 450 in accordance with the present invention utilizing a diamagnetic or non-magnetic member 452 disposed for movement between a fixed array 454 of permanent magnets 456 and at least one rotatable array 460 of permanent magnets 462. The array 460 is rotatable about an axis 466 as indicated by the arrow θ, which provides maximum braking force at θ=0 and lesser braking force as the angle θ is increased.

Rotation of the array 460 may be provided by an actuator 470 coupled to the array 460 in a conventional manner and velocity of the member 452 may be determined by a sensor 471 for enabling rotation of the array 460 as a function of member 452 velocity.

Alternatively, the array 460 may be spring 472 loaded in order to provide rotation of the array 466 as a function of velocity of the member 452 between the arrays 454, 460. This movement is akin to the linear movement of the array 408 hereinabove described in connection with the embodiment 400 of the present invention.

Turning on to FIG. 18, there is diagramed eddy current brake mechanism 500 generally including a diamagnetic or non-magnetic member 502 as hereinbefore described in connection with earlier embodiments along with a first movable linear array 504 of permanent magnets 506 and a second movable linear array 508 of permanent magnets 510 disposed in a spaced apart relationship for enabling passage of the member 502 therebetween.

The magnet arrays 504, 508 establish a plane 514, and an actuator, which may be pneumatic or electric 516, is coupled to the arrays 504, 508 as indicated by the dashed line 520 in a conventional manner for adjusting the eddy current induced in the member 502, and concomitant braking force, through movement of the arrays 504, 508 in a direction perpendicular to the plane 514 as indicated by the arrow 522. Movement of the arrays 504, 508 in a downward direction provides for less magnetic coupling with the member 502 hence less braking action. The member 502 may also be moved in the direction of arrow 522 in order to change the magnetic coupling.

Again, a sensor 524 may be provided in order that movement of the arrays 504, 408 may be controlled as a function of member 502 velocity.

FIG. 19 diagrams another eddy current brake mechanism 550 in accordance with the present invention for a moving apparatus 552 having spaced apart wheels 554, 556, slides, maglev devices, etc., for engagement with parallel rails 558, 560, slides, maglev devices, etc. The mechanism 550 includes a diamagnetic or non-magnetic member 570 depending from the moving apparatus 552 between the wheels 554, 556.

First and second linear arrays 572, 574 of permanent magnets 576, 578 are disposed in a spaced apart relationship for enabling passage of the member 570 therebetween in order to induce eddy currents and concomitant braking force in the member 570 upon passage of the member 570 between the arrays 572, 574.

Springs 580, 582, which may have a selected spring constant k, are disposed between the moving apparatus 552 and wheels 554, 556 in a conventional suspension manner and are operable for lowering the member 570 between the arrays 572, 574 as a function of car weight, thereby adjusting the induced eddy current and braking force as a function of car weight.

That is, when the mass of the moving apparatus 552 increases (for instance, if the moving apparatus is full of cargo, payload or passengers) the moving apparatus is suspended lower and the moving member 570 moves farther down inside the air gap or space 590 between the arrays 572, 574. This provides more braking force which is advantageous for the heavier moving apparatus.

Although there has been hereinabove described a specific eddy current braking apparatus with adjustable braking force in accordance with the present invention for the purpose of illustrating the manner in which the invention may be used to advantage, it should be appreciated that the invention is not limited thereto. That is, the present invention may suitably comprise, consist of, or consist essentially of the recited elements. Further, the invention illustratively disclosed herein suitably may be practiced in the absence of any element which is not specifically disclosed herein. Accordingly, any and all modifications, variations or equivalent arrangements which may occur to those skilled in the art, should be considered to be within the scope of the present invention as defined in the appended claims.

Claims

1. An eddy current brake mechanism comprising: a first array of permanent magnets; a second array of permanent magnets disposed adjacent said fixed array of permanent magnets; a diamagnetic or non-magnetic member disposed for travel between the first and second arrays of magnets; and velocity sensitive magnet array moving apparatus connected to at least one of the first and second arrays of permanent magnets for adjusting braking force against the member as a function of member velocity between the magnet arrays.

2. The brake mechanism according to claim 1 wherein the first and second arrays are linear and the array moving apparatus comprises a linear actuator causing array movement in a direction parallel to the member travel.

3. The brake mechanism according to claim 1 wherein the first and second arrays are linear and the array moving apparatus comprises a linear actuator causing array movement in a direction transverse to the member travel.

4. The brake mechanism according to claim 1 wherein the array moving apparatus comprises a spring.

5. The brake mechanism according to claim 1 wherein at least one of the first and second arrays is rotatable about an axis and the array moving apparatus comprises an actuator for rotating at least one of arrays.

6. The brake mechanism according to claim 1 wherein the at least one of the arrays is rotatable about an axis and the array moving apparatus comprises a spring for rotating at least one of the arrays.

7. The brake mechanism according to claim 1 wherein the array moving apparatus comprises a linear actuator causing array movement in a direction perpendicular to a plane established by the magnet arrays.

8. An eddy current brake mechanism comprising: a first array of permanent magnets; a second array of permanent magnets disposed adjacent said first array of permanent magnets; a diamagnetic or non-magnetic member disposed for travel between the first and second arrays of magnets; a member velocity sensor; and velocity sensitive magnet array moving apparatus connected to at least one of the first and second arrays of permanent magnets and sensor for adjusting braking force against the member as a function of member velocity between the magnet arrays.

9. The brake mechanism according to claim 8 wherein the first and second arrays are linear and the array moving apparatus comprises a linear actuator causing array movement in a direction parallel to the member travel.

10. The brake mechanism according to claim 8 wherein the first and second arrays are linear and the array moving apparatus comprises a linear actuator causing array movement in a direction transverse to the member travel.

11. The brake mechanism according to claim 8 wherein the at least one of the arrays is rotatable about an axis and the array moving apparatus comprises an actuator for rotating the rotatable array.

12. The brake mechanism according to claim 8 wherein at least one of the arrays is rotatable about an axis and the array moving apparatus comprises a spring for rotatable the moveable array.

13. An eddy current brake mechanism comprising: a first array of permanent magnets; a second array of permanent magnets disposed adjacent said fixed array of permanent magnets; a diamagnetic or non-magnetic member disposed for travel between the first and second arrays of magnets; and velocity sensitive member moving apparatus connected to the member for adjusting braking force against the member as a function of member velocity between the magnet arrays.

14. The brake mechanism according to claim 13 wherein the first and second arrays are linear.

15. The brake mechanism according to claim 13 wherein the first and second arrays are linear and the member moving apparatus comprises a linear actuator causing member movement in a direction transverse to the member travel.