U.S. patent application number 13/024974 was filed with the patent office on 2011-09-08 for guidance system for a medical facility.
Invention is credited to Peter Grubling, Klaus Herrmann, Ulrich Weber.
Application Number | 20110214588 13/024974 |
Document ID | / |
Family ID | 43903808 |
Filed Date | 2011-09-08 |
United States Patent
Application |
20110214588 |
Kind Code |
A1 |
Grubling; Peter ; et
al. |
September 8, 2011 |
GUIDANCE SYSTEM FOR A MEDICAL FACILITY
Abstract
A guidance system for a medical facility includes at least one
floor element that extends along a path of the medical facility and
is arranged in a floor area of the path. The at least one floor
element is configured for magnetic interaction such that through
the magnetic interaction of the floor element with a magnetic guide
element arranged on a mobile transport device, a magnetic
attraction is generated. The mobile transport device is guided
along the at least one floor element by the generated magnetic
attraction during forward motion of the mobile transport device
along the path through the medical facility.
Inventors: |
Grubling; Peter;
(Weimar/Lahn, DE) ; Herrmann; Klaus; (Nurnberg,
DE) ; Weber; Ulrich; (Friedrichsdorf, DE) |
Family ID: |
43903808 |
Appl. No.: |
13/024974 |
Filed: |
February 10, 2011 |
Current U.S.
Class: |
104/118 |
Current CPC
Class: |
B60L 2200/26 20130101;
A61G 7/08 20130101; H02K 41/03 20130101; G05D 2201/0206 20130101;
A61B 6/0487 20200801; B60L 5/005 20130101; A61G 2203/22 20130101;
G05D 1/0265 20130101; A61G 5/1051 20161101; A61G 1/02 20130101;
A61G 2203/36 20130101; A61G 2210/50 20130101 |
Class at
Publication: |
104/118 |
International
Class: |
B61B 13/04 20060101
B61B013/04 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 15, 2010 |
DE |
10 2010 008 014.4 |
Claims
1. A guidance system for a medical facility, the guidance system
comprising: a floor element that extends along a path through the
medical facility and is arranged in a floor area of the path; and a
magnetic guide element arranged on a mobile transport device,
wherein the floor element is configured for magnetic interaction
such that a magnetic attraction is generated through the magnetic
interaction of the floor element with the magnetic guide element,
and wherein the magnetic guide element is operable to guide the
mobile transport device along the floor element during forward
motion of the mobile transport device along the path through the
medical facility.
2. The guidance system as claimed in claim 1, wherein the floor
element comprises an elongated body made of a ferromagnetic
material.
3. The guidance system as claimed in claim 1, wherein the floor
element tapers at a start, an end or the start and the end of the
path.
4. The guidance system as claimed in claim 1, wherein the floor
element comprises a component that generates a magnetic field.
5. The guidance system as claimed in claim 1, wherein the floor
element is set into the floor area.
6. A medical facility comprising: a patient transport corridor with
a guidance system, the guidance system comprising: a floor element
that extends along a path of the medical facility and is arranged
in a floor area of the path; and a magnetic guide element that is
arranged on a mobile transport device, wherein the floor element is
configured for magnetic interaction such that a magnetic attraction
is generated through the magnetic interaction of the floor element
with the magnetic guide element, and wherein the magnetic guide
element is operable to guide the mobile transport device along the
floor element during forward motion of the mobile transport device
along the path through the medical facility.
7. The medical facility as claimed in claim 6, further comprising a
treatment or diagnostic room of a particle therapy system, wherein
the path is at least partly in the treatment or diagnostic
room.
8. A mobile transport device comprising: a magnetic guide element
that is configured to come into magnetic interaction with a floor
element such that through the magnetic interaction a magnetic
attraction is generated, the floor element being arranged in a
floor area and extending along a path, wherein the magnetic guide
element is operable to guide the mobile transport device on the
path during forward motion of the mobile transport device along the
path.
9. The mobile transport device as claimed in claim 8, wherein the
magnetic guide element comprises a permanent magnet.
10. The mobile transport device as claimed in claim 8, wherein the
magnetic guide element comprises a plastic coating.
11. The mobile transport device as claimed in claim 8, wherein the
magnetic guide element is at a distance less than 10 cm from the
floor area.
12. The mobile transport device as claimed in claim 8, further
comprising a front part located forwards relative to the direction
of motion, wherein the magnetic guide element is arranged in the
front part.
13. The mobile transport device as claimed in claim 12, further
comprising: a rear part located backwards relative to the direction
of motion; and another magnetic guide element, the other guide
element being arranged in the rear part.
14. The mobile transport device as claimed in claim 12, further
comprising: a steering mechanism; and a wheel that is connected to
the magnetic guide element via the steering mechanism, wherein the
steering mechanism is operable to transfer the magnetic attraction
exerted on the magnetic guide element to the wheel.
15. The mobile transport device as claimed in claim 8, wherein the
magnetic guide element comprises two oppositely poled permanent
magnets arranged at a distance from each other.
16. A method for steering a mobile transport device along a path in
a medical facility, the method comprising: magnetically interacting
a guidance system having a floor element arranged along the path
with a magnetic guide element of the mobile transport device; and
guiding the mobile transport device along the path using a magnetic
attraction between the magnetic guide element and the floor element
when the mobile transport device is moved forward.
17. The guidance system as claimed in claim 2, wherein the
ferromagnetic material comprises ferrous metal sheet or
ferromagnetic steel.
18. The guidance system as claimed in claim 4, wherein the
component that generates a magnetic field comprises a permanent
magnet.
19. The guidance system as claimed in claim 5, wherein the floor
element forms a smooth surface with the floor area.
20. The mobile transport device as claimed in claim 9, wherein the
permanent magnet is a Neodymium Iron Boron magnet.
Description
[0001] This application claims the priority benefit of DE 10 2010
008 014.4 filed Feb. 15, 2010, which is hereby entirely
incorporated by reference.
BACKGROUND
[0002] The present embodiments relate to a guidance system for a
medical facility.
[0003] In a medical facility (e.g., a medical system) such as, for
example, a clinic, patients positioned on a patient transport
device (e.g., trolley) may be conveyed great distances from one
room to the next in order to conduct particular
investigations/therapies in certain rooms, for example.
[0004] One example of a medical system is a particle therapy
system. Particle therapy is an established method for the treatment
of tumor conditions, for example. As a particle therapy system is
comparatively costly, a particle therapy system may be operated in
an efficient manner. In order to facilitate efficient operation, a
known approach is to irradiate a patient in a treatment room and to
undertake little preparation/aftercare on the patient in the
treatment room. Preparation includes, for example, the
immobilization of a patient. The preparation/aftercare may thus
take place in a separate room.
[0005] In some cases, the patient transport device may travel
considerable distances between the preparation room and the
treatment room over routes that for reasons of radiation
protection, may be maze-like in nature. The patient may thus be
conveyed backwards and forwards between the preparation room and
the treatment room.
[0006] In the prior art, the transport of a patient couch may be
monitored using an optical system, and the patient couch may be
steered automatically via an integrated control mechanism.
SUMMARY AND DESCRIPTION
[0007] The present embodiments may obviate one or more of the
drawbacks or limitations in the related art. For example, in one
embodiment, a guidance system for medical facilities, which
facilitates the conveyance of a mobile transport device in a
readily controllable manner and minimizes a force used for the
conveyance, is provided. In another embodiment, a mobile transport
device that is operable to be conveyed along the guidance system in
a readily controllable manner and with a minimum of force is
specified. In yet other embodiments, a medical facility including
the guidance system and a method for steering a mobile transport
device, which provide simple and safe guidance, are provided.
[0008] One embodiment of a guidance system for medical facilities
includes at least one floor element that extends along a path
(e.g., a target path) of the medical facility and is arranged in a
floor region of the path. The floor element is configured for
magnetic interaction such that by the magnetic interaction of the
floor element with a magnetic guide element arranged on a mobile
transport device, a magnetic attraction may be generated. The
mobile transport device may be guided along the floor element by
the magnetic attraction during forward motion of the mobile
transport device along the path through the medical facility. The
floor element may be manufactured from ferrous metal sheet and/or
ferromagnetic steel, as examples.
[0009] The guidance system, with an appropriately configured mobile
transport device and by employing the magnetic attraction, may
guide the mobile transport device on the path. The magnetic
interaction brings about a magnetic attraction between the floor
element and the magnetic guide element. The magnetic attraction
directly exercises a resetting force on the mobile transport
device. The magnetic attraction exerts a direct force on the mobile
transport device so that upon being moved forwards, the transport
device is drawn to the target path, which is characterized by the
floor element. Should the mobile transport device veer off track
and diverge from the path, the magnetic attraction causes the
mobile transport device to be drawn back laterally to the path. In
the vicinity of the floor element (e.g., a rail), the greater the
divergence from the floor element (e.g., from the central axis of
the rail), the larger the resetting force is.
[0010] The guidance system includes elements that enter into
magnetic interaction with each other. The guidance system may be
constructed in a comparatively simple manner and may require little
maintenance but nevertheless, offers effective and contact-free
guidance of the mobile transport device.
[0011] The guidance system serves to prevent the mobile transport
device, which is being moved forward along the path, from veering
off the target path at locations including numerous corners, for
example, and colliding with a wall. Collisions of this kind may
pose a problem (e.g., in radiation therapy) if a patient is already
stereotactically fixed and is not to be physically shaken.
[0012] Compared with optical or electromagnetically-inductive
sensors and a corresponding electronic controller used to control
the mobile transport device, the guidance system offers a series of
advantages. The complex sensor and control technology is
cost-intensive and may also be susceptible to faults. The
controller and the motor mechanism that are arranged on the mobile
transport device result in increased space requirements and greater
weight. An energy supply for the controller is also needed. The
energy supply may include a battery with a charge status that is
monitored. Alternatively, the energy supply may be supplied via
cables, which give rise to significant disadvantages in terms of
freedom of movement. The same advantages also apply compared with
active control of the mobile transport device. Active control makes
use of induction loops attached to the floor for the correct
guidance of the mobile transport device.
[0013] Compared with a floor-mounted rail in mechanical contact
with the mobile transport device to guide the mobile transport
device, the guidance system of the present embodiments offers the
advantage of magnetic and thus contactless guidance. The safety of
the medical facility may thereby be improved, as mechanical rail
systems represent dangerous trip hazards or uneven floors and also
present cleaning problems from a hygiene perspective. The guidance
system of the present embodiments may provide a smooth floor.
[0014] In one embodiment, the floor element includes an elongated,
rail-like body made of ferromagnetic material. The elongated,
rail-like body includes, at least partially, a ferrous metal sheet
and/or ferromagnetic steel.
[0015] The use of a ferromagnetic material provides magnetic
interaction with a magnetic guide element of the mobile transport
device. A ferrous metal sheet and/or the ferromagnetic steel may be
several centimeters wide (e.g., between 5 and 15 cm) and several
millimeters thick (e.g., between 2 and 20 mm).
[0016] The floor element (e.g., the elongated, rail-like body) may
taper at a start of the path and/or at an end of the path. The
tapering causes the magnetic interaction with the mobile transport
device to weaken at the start and/or the end, facilitating the
mobile transport device to be led to the floor element without
jolting.
[0017] In one embodiment, the floor element includes an element
generating a magnetic field (e.g., a permanent magnet). A curved
section may, for example, be configured in this way. The magnetic
effect may be strengthened in this manner. The magnet or magnets
used in the curved section is/are oppositely poled to the guide
element of the mobile transport device so that an attractive effect
arises.
[0018] The floor element may be set into the floor. The floor
element may, for example, be prepared or incorporated with the
floor covering such that an overall smooth surface is produced
(e.g., there are no rims, channels or edges).
[0019] The medical facility (e.g., medical system) of the present
embodiments includes the guidance system discussed above. The
medical system may be a particle therapy system, for example. The
particle therapy system includes at least one treatment or
diagnostic room and one preparation room, in which a patient is
prepared for a subsequent diagnosis or treatment.
[0020] The guidance system is arranged along the path at least
between winding stretches between the preparation room and the
treatment or diagnostic room. The workflow may be simplified in
this way.
[0021] The mobile transport device (e.g., a patient transport
device) of the present embodiments includes a magnetic guide
element. The magnetic guide element is configured to enter into
magnetic interaction with a floor element such that by the magnetic
interaction, a magnetic attraction may be generated. The floor
element may be arranged in a floor region and may extend along a
path. The mobile transport device may be laterally guided on the
path by the generated magnetic attraction during forward motion of
the mobile transport device along the path.
[0022] The magnetic guide element may include a permanent magnet.
The permanent magnet may permit a weight and space-saving
construction of the mobile transport device. The permanent magnet
may, for example, be a Neodymium Iron Boron (NdFeB) magnet. NdFeB
magnets are strong, provide a high degree of attraction and thus
sufficiently positive guidance. A magnet diameter of 125 mm, for
example, may provide a holding force of 130 kg. NdFeB magnets may
have a diameter of between 100 and 200 mm and a thickness of 10 to
30 mm, for example. NdFeB magnets retain magnetic properties for a
period of time of 10 years or longer, for example.
[0023] The permanent magnet may be provided with a plastic coating.
The plastic coating may be several mm in thickness, for example.
The plastic coating prevents the permanent magnet from directly
contacting or "clashing" with the floor element (e.g., when the
mobile transport device is sprung) and thus no rigidly fixed
distance between the permanent magnet and the floor element
applies.
[0024] The magnetic guide element is arranged such that the
magnetic guide element is a minimal distance from the floor (e.g.,
less than 10 cm). In one embodiment, the magnetic guide element is
less than 5 cm from the floor. In another embodiment, the magnetic
guide element is between 2 and 20 mm from the floor. A high degree
of attraction is provided in this way.
[0025] In one embodiment, the magnetic guide element is arranged in
a front part (e.g., half) of the mobile transport device, where the
front half is defined in relation to the standard direction of
motion (e.g., a direction of motion preferably adopted during use
in a standard manner). The magnetic guide element may, for example,
be arranged such that the magnetic guide element is arranged in
front of a furthest forward wheel in the direction of motion. The
transport device may include a front axle that is characterized by
the position of the furthest forward wheel. The magnetic guide
element may be arranged in the region of the front axle (e.g., in
the same position as (in line with), slightly ahead of or behind
the front axle in relation to the direction of motion). The
position of the magnetic guide element may be selected on the basis
of size, axle construction, weight distribution and/or the
characteristics of the corners to be negotiated.
[0026] The magnetic guide element may lie on a longitudinal central
axis of the mobile transport device.
[0027] In one embodiment, the mobile transport device includes
another magnetic guide element. The other magnetic guide element is
arranged in a rear part (e.g., a rear half) of the mobile transport
device. The rear part may be towards a back of the mobile transport
device relative to the direction of motion. The other magnetic
guide element may, for example, be arranged such that the magnetic
guide element is located behind a rearmost wheel of the mobile
transport device. The mobile transport device includes a rear axle
that is characterized by the position of the rearmost wheel. The
other guide element may be arranged in an area of the rear axle
(e.g., in the same position as (in line with), slightly ahead of or
behind the rear axle relative to the direction of motion). Such an
arrangement may be helpful if the mobile transport device is to be
shifted backwards in addition to forward motion along the path.
[0028] In one embodiment, a wheel is linked to the magnetic guide
element via a steering mechanism. The magnetic attraction exerted
on the magnetic guide element may be transferred to the wheel via
the steering mechanism. The wheel position may be at least
partially influenced by the magnetic attraction, such that the
position of the wheel affects steering of the mobile transport
device along the path and thus affects redirection of the mobile
transport device to the target path.
[0029] In one embodiment of a method for steering a mobile
transport device along a path in a medical facility, in which a
guidance system with a floor element is arranged along the path,
the floor element comes into magnetic interaction with a magnetic
guide element of the mobile transport device such that when moved
forward, the mobile transport device is steered along the floor
element by a magnetic attraction between the magnetic guide element
and the floor element.
[0030] The preceding and the following description of the
individual features relate both to the device and to the method,
without this being explicitly mentioned in every single case; the
individual features disclosed may also be significant to the
present embodiments in other combinations than those discussed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] FIG. 1 shows a view of an irradiation room of a particle
therapy system with an access path, along which one embodiment of a
guidance system is arranged;
[0032] FIG. 2 shows an enlarged representation of an area from FIG.
1 indicated by II;
[0033] FIG. 3 shows an enlarged representation of an area from FIG.
1 indicated by III;
[0034] FIG. 4 shows a side view of the area from FIG. 3 indicated
by IV;
[0035] FIG. 5 shows a side view of one embodiment of a patient
transport device;
[0036] FIG. 6 shows a top view of one embodiment of the patient
transport device;
[0037] FIG. 7 shows a front view of one embodiment of the patient
transport device;
[0038] FIG. 8 shows an enlarged representation of an area from FIG.
7 indicated by VIII;
[0039] FIG. 9 shows a representation corresponding to FIG. 8 with a
lateral displacement of a magnet relative to a magnetic rail;
[0040] FIG. 10 shows a side view of one embodiment of a patient
transport device;
[0041] FIG. 11 shows a side view of one embodiment of a patient
transport device with a steering mechanism;
[0042] FIG. 12 shows a top view of one embodiment of the patient
transport device shown in FIG. 11;
[0043] FIG. 13 shows a side view of one embodiment of the patient
transport device shown in FIG. 5; and
[0044] FIG. 14 shows one embodiment of the structure of a magnetic
guide element with two oppositely poled permanent magnets.
DETAILED DESCRIPTION OF THE DRAWINGS
[0045] FIG. 1 shows part of a particle therapy system 11 with a
treatment room 13. For reasons of radiation protection, the
treatment room 13 may be entered via a maze-like access path 15
(e.g., an entry path). A patient on a patient couch is conveyed
along the path 15 in order to reach the treatment room 13. A
guidance system 17 is arranged along the path 15. With the aid of
the guidance system 17, passage of the patient couch is supported
along the path 15, as is described in greater detail with reference
to the following figures.
[0046] The guidance system 17 includes a floor element 19
configured in rail-like form. The floor element comes into magnetic
interaction with the patient couch or another transport device. The
floor element 19 tapers in end regions 21 that are, for example, in
a preparation room (e.g., at the start of the maze-like path 15)
and/or in the treatment room 13.
[0047] The tapering of the floor element 19 is shown more clearly
in FIG. 2, which represents an area indicated by II in FIG. 1 in
enlarged form. The tapering of the floor element 19 in the end
regions 21 reduces the magnetic interaction with the floor element
19 at the end regions 21. Because of the reduced magnetic
interaction, the patient couch may be introduced into the guidance
system 17 gently and largely without jolting.
[0048] FIG. 3 shows an enlarged representation of an area of FIG. 1
indicated by III. The floor element 19 may be differently
constructed in different sections. In sections that generally take
a straight course, the floor element 19 may include an elongated
ferrous metal sheet or a ferromagnetic steel sheet 23 (e.g., a
ferrous metal sheet). In other sections (e.g., highly tortuous
sections 25), the floor element 19 includes a plurality of small
permanent magnets 27 (e.g., 5 mm to 20 mm in size). As a result of
the use of the plurality of small permanent magnets 27, the patient
couch may continuously travel, so that jolting caused by the
attraction forces of the individual floor magnets is largely
avoided.
[0049] FIG. 4 shows a side view of an area from FIG. 3 identified
with IV. Both the ferrous metal sheet 23 and the plurality of small
permanent magnets 27 are set into the floor and provided with a
coating 29 so that a smooth floor surface results. The magnetic
field lines 31 are also shown in FIG. 4. The magnetic field lines
31 symbolize the magnetic field produced by the small permanent
magnets 27. The magnetic field of the small permanent magnets 27 is
oriented such that through interaction with a magnetic guide
element of the patient couch, an attraction force is created.
[0050] FIG. 5 shows a side view of one embodiment of a mobile
patient couch 33 (e.g., a patient bed or a patient table). The
mobile patient couch 33 includes a table top 35, and a patient (not
shown) is positioned on the table top 35. The patient couch 33 may,
for example, include four wheels 37 so that the patient couch 33 is
mobile. In other embodiments, more wheels (e.g., five or six
wheels) or fewer wheels may be provided. An operative (not shown)
may push the patient couch 33 ahead of the operative. As a result
of the construction of the patient couch, the patient couch may
have a preferred direction of motion, in which the patient couch is
conveyed during standard use. The patient couch 33 may include a
handle 39 for this purpose. In one embodiment, two of the four
wheels 37 or all of the four wheels 37 are castering, so winding
stretches may also be negotiated with the patient couch 33.
[0051] A permanent magnet 41 may be arranged in a frontal area of
the patient couch 33 (e.g., relative to the direction in which the
patient couch 33 may be propelled in standard use). In one
embodiment, the permanent magnet 41 may include a material
including Neodymium Iron Boron. As shown in FIG. 5, the permanent
magnet 41 may be arranged ahead of a front axle (e.g., an axle for
front steerable wheels 37). Alternatively, the permanent magnet 41
may be arranged in line with or slightly behind the front axle. The
permanent magnet 41 is at a small distance (e.g., between 1 mm and
10 mm) from the floor.
[0052] FIG. 6 shows a top view of one embodiment of the patient
couch 33 with the table top 35 removed. FIG. 6 shows the floor
element 19, which came into magnetic interaction with the permanent
magnet 31 of the patient couch 33. When the patient couch 33 is
pushed in the direction of the arrow, the magnetic attraction
between the permanent magnet 41 and the floor element 19 causes the
patient couch 33 to be guided along the floor element 19.
[0053] FIG. 7 shows a front view of one embodiment of the patient
couch 33. FIG. 7 shows that the floor element 19 is set into the
floor. As a result of the floor element 19 being set into the
floor, a smooth floor surface without grooves and edges is
created.
[0054] FIG. 8 shows an enlarged representation of an area from FIG.
7 indicated by VIII. The magnetic interaction between the permanent
magnet 41 and the floor element 19, symbolized by magnetic field
lines 43, is shown in FIG. 8. The permanent magnet 41 may be
provided with a plastic coating 42.
[0055] FIG. 9 illustrates the situation that may occur when upon
being moved forward, the patient couch 33 moves away from the floor
element 19. As a result of the magnetic attraction 45 (e.g.,
forces), the permanent magnet 41 is drawn towards the floor element
19 so that the patient couch 33 is automatically guided along the
floor element 19. This happens with very little extra human effort,
as the forces do not have a braking effect. The forces are absorbed
through the wheels and may generate a slightly increased rolling
friction as a result of the greater vertical bearing force of the
castors.
[0056] FIG. 10 shows one embodiment of a patient couch 33 that
includes another guide element 47 compared with the patient couch
33 shown in FIG. 5. The other guide element 47 is arranged in a
rear area (e.g., part) of the patient couch 33. The other guide
element 47 may be advantageous when the patient couch 33 is moved
in an opposite direction of the preferred direction of motion.
[0057] FIG. 11 shows a patient couch 33, which differs from the
patient couch shown in FIG. 5 in that the permanent magnet 41 is
coupled with front steerable wheels 37' (e.g., two front wheels)
via a steering mechanism 49.
[0058] The effect of the steering mechanism 49 is illustrated in
greater detail within FIG. 12. The two front wheels 37' are guided
on a parallel course by the steering mechanism 49. The steering
mechanism 49 is coupled with the magnetic guide element (e.g., with
the permanent magnet 41) such that the steering mechanism 49
directs the two front wheels 37' in the direction of a target curve
according to the force exerted on the permanent magnet 41, by which
the permanent magnet 41 is attracted to the floor element 19.
[0059] If the patient couch 33 diverges from the target curve
(e.g., so the permanent magnet 41 is no longer centered over the
floor element 19), a horizontal moment has an effect on the
permanent magnet 41 that works towards the floor element 19. In
this case, the significantly greater vertical moment plays no role.
The horizontal moment is transferred to the steering of the front
wheels 37' via a lever mechanism, so that the patient couch 33 is
guided back to the target curve.
[0060] FIG. 13 shows a side view of one embodiment of a mobile
patient couch 33 that is slightly modified compared with FIG. 5.
The permanent magnet 41 is arranged between the front wheels 37 and
the rear wheels 37.
[0061] FIG. 14 shows one embodiment of the guide element, in which
the single permanent magnet is replaced by two oppositely poled
permanent magnets 41', 41'' arranged next to each other. The
opposite poling is symbolized by the thick arrows. The two
oppositely poled permanent magnets 41', 41'' may be made of NdFeB
and may be cuboid in form (e.g., with dimensions of
50.times.75.times.10 mm), for example. In one embodiment, a
distance between the floor element 19 and the permanent magnets
41', 41'' is 10 mm. A floor covering 51 (e.g., consisting of
linoleum) may be arranged over the floor element 19 and may be a
steel rail (e.g., an 8 mm thick steel rail).
[0062] A narrow spacer 53 made of plastic, for example, may be
inserted between the two oppositely poled permanent magnets 41',
41''. The narrow spacer 53 may maintain a distance of 20 mm between
the two oppositely poled permanent magnets 41', 41''.
[0063] A shared yoke 55 made of ferromagnetic material (e.g., a
thick steel plate), for example, may be disposed over the two
oppositely poled permanent magnets 41', 41''.
[0064] The advantage of this arrangement lies in the fact that the
magnetic field lines run in a self-contained manner through a
system including the floor element 19, the permanent magnet 41',
the yoke 55, and the permanent magnet 41''. A high degree of
attraction is thus achieved with small/low-weight magnets, and the
magnetic stray fields (e.g., unused field lines outside the system)
are reduced.
[0065] While the present invention has been described above by
reference to various embodiments, it should be understood that many
changes and modifications can be made to the described embodiments.
It is therefore intended that the foregoing description be regarded
as illustrative rather than limiting, and that it be understood
that all equivalents and/or combinations of embodiments are
intended to be included in this description.
* * * * *