U.S. patent application number 10/034014 was filed with the patent office on 2002-08-22 for door suspension apparatus.
Invention is credited to Rennetaud, Jean-Marie, Zhou, Tian.
Application Number | 20020112410 10/034014 |
Document ID | / |
Family ID | 8175098 |
Filed Date | 2002-08-22 |
United States Patent
Application |
20020112410 |
Kind Code |
A1 |
Zhou, Tian ; et al. |
August 22, 2002 |
Door suspension apparatus
Abstract
A door suspension assembly includes a ferromagnetic flat plate
horizontally extending from a support rail adapted to be attached
to a door frame above a doorway or entrance portal. Two supporting
blocks each have an opening in which a cylindrical bearing with an
axial hole is located. The supporting blocks are attached to a door
panel. Connectors extend downwardly from the flat plate and support
a tube that extends through the holes in the bearings. A magnet
array is supported by an upper plate attached to upper ends of the
supporting blocks with a small magnetic gap between the magnet
array and the flat plate such that the magnet array generates a
magnetic force lifting the supporting blocks and the door panel. A
primary of a linear motor is attached to the upper plate between
the supporting blocks and cooperates with a secondary located in
the interior of the tube to move the door panel relative to the
flat plate.
Inventors: |
Zhou, Tian; (Littau, CH)
; Rennetaud, Jean-Marie; (Chester, NJ) |
Correspondence
Address: |
MACMILLAN SOBANSKI & TODD, LLC
ONE MARITIME PLAZA FOURTH FLOOR
720 WATER STREET
TOLEDO
OH
43604-1619
US
|
Family ID: |
8175098 |
Appl. No.: |
10/034014 |
Filed: |
January 3, 2002 |
Current U.S.
Class: |
52/30 ; 187/313;
187/336; 52/204.1 |
Current CPC
Class: |
E05D 2015/0695 20130101;
E05F 15/60 20150115; H02K 41/03 20130101; H02K 7/08 20130101 |
Class at
Publication: |
52/30 ; 52/204.1;
187/313; 187/336 |
International
Class: |
E04H 006/06 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 22, 2000 |
EP |
00811229.4 |
Claims
What is claimed is:
1. A door suspension assembly comprising: a substantially flat
plate formed of ferromagnetic material extending generally
horizontally and adapted to be attached to a door frame above a
doorway; a guide means having an opening formed therethrough and
adapted to support a door panel; a rail extending through said
opening and extending at least approximately a length of a required
door travel; at least two connectors attached to said flat plate
and extending downwardly supporting said rail and said guide means;
and a magnet means attached to said guide means and spaced from
said plate to form a small magnetic gap, such that said magnet
means generates a magnetic force lifting said guide means toward
said plate whereby when a door panel is suspended from said guide
means, said magnet means generates a magnetic force sufficient to
support at least most of a weight of the door panel.
2. The door suspension assembly according to claim 1 including a
bearing having a generally cylindrical shape with an axial hole
formed therein, said bearing being mounted in said opening of said
guide means and said rail extending through said axial hole.
3. The door suspension assembly according to claim 2 wherein said
bearing is made of a synthetic material for sliding contact with
said rail.
4. The door suspension assembly according to claim 1 wherein said
guide means includes two supporting blocks each having a lower
surface attached to a lower plate, including connection means
extending from said lower plate and adapted to be attached to a
door panel, wherein said supporting blocks each have an upper
surface attached to an upper plate, and wherein said magnet means
is attached to said upper plate.
5. The door suspension assembly according to claim 1 wherein said
rail is a tube.
6. The door suspension assembly according to claim 5 wherein said
tube is made of a non-magnetic material and including a linear
motor having a primary mounted on said guide means and a secondary
mounted in an interior of said tube.
7. The door suspension assembly according to claim 6 wherein said
guide means includes two spaced apart supporting blocks said
primary is located between said supporting blocks.
8. The door suspension assembly according to claim 1 wherein said
magnet means is one of a plurality of neodymium rare earth
permanent magnets and a plurality of ferrite permanent magnets.
9. The door suspension assembly according to claim 1 including a
support means attached to said flat plate, said support means being
adapted for attachment to a crosspiece of a door frame.
10. A door suspension assembly for an elevator comprising: a
substantially flat plate formed of ferromagnetic material extending
generally horizontally and adapted to be attached to a door frame
above an elevator doorway; a guide means having an opening formed
therethrough; a door panel suspended from said guide means; a rail
extending through said opening and extending at least approximately
a length of a required travel of said door panel; at least two
connectors attached to said flat plate and extending downwardly
supporting said rail and said guide means; and a magnet means
attached to said guide means and spaced from said plate to form a
small magnetic gap, such that said magnet means generates a
magnetic force lifting said guide means toward said plate with a
magnetic force sufficient to support at least most of a weight of
said door panel.
11. The door suspension assembly according to claim 10 wherein said
guide means includes two supporting blocks each having a lower
surface attached to a lower plate, including connection means
extending from said lower plate and attached to said door panel,
wherein said supporting blocks each have an upper surface attached
to an upper plate, and wherein said magnet means is attached to
said upper plate.
12. The door suspension assembly according to claim 11 wherein said
opening extends through said supporting blocks, and including a
pair of bearings having a generally cylindrical shape with an axial
hole formed therein, each said bearing being mounted in said
opening of an associated one of said supporting blocks and said
rail extending through said axial holes.
13. The door suspension assembly according to claim 12 wherein said
bearings are made of a synthetic material for sliding contact with
said rail.
14. The door suspension assembly according to claim 10 wherein said
rail is a tube.
15. The door suspension assembly according to claim 14 wherein said
tube is made of a non-magnetic material and including a linear
motor having a primary mounted on said guide means and a secondary
mounted in an interior of said tube.
16. The door suspension assembly according to claim 15 wherein said
guide means includes two spaced apart supporting blocks said
primary is located between said supporting blocks.
17. The door suspension assembly according to claim 10 wherein said
magnet means is one of a plurality of neodymium rare earth
permanent magnets and a plurality of ferrite permanent magnets.
18. A door suspension assembly comprising: a support means having a
substantially flat plate formed of ferromagnetic material extending
generally horizontally, said support means adapted to be attached
to a door frame above a doorway; a guide means including a pair of
spaced apart supporting blocks each having an opening formed
therethrough and adapted to support a door panel; a rail extending
through said openings and extending at least approximately a length
of a required door travel; at least two connectors attached to said
flat plate and extending downwardly supporting said rail and said
guide means; and a magnet means attached to said guide means and
spaced from said plate to form a small magnetic gap, such that said
magnet means generates a magnetic force lifting said guide means
toward said plate whereby when a door panel is suspended from said
guide means, said magnet means generates a magnetic force
sufficient to support at least most of a weight of the door
panel.
19. The door suspension assembly according to claim 18 wherein said
rail is a tube made of a non-magnetic material and including a
linear motor having a primary mounted on said guide means and a
secondary mounted in an interior of said tube.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates generally to a door suspension
assembly and, in particular, to a door suspension apparatus for an
elevator car door.
[0002] The European patent application No. 0 841 286 A1 discloses
an elevator car door suspension assembly for opening and closing
elevator car doors including a linear induction motor having a pair
of movable motor primaries attached to a respective door hanger of
each door and a stationary motor secondary attached to a header
bracket which is secured to the elevator car, and wherein the motor
secondary includes a substantially flat plate which is vertically
disposed and is preferably made of a conductive metal such as
copper. In this system, in which the door panels are guided by
separate rails, a pair of flexible ropes and wheels is needed to
keep both panels moving synchronously.
[0003] Another known design is a driving apparatus for doors such
as is disclosed in U.S. Pat. No. 5,172,518 (Yoshino). This driving
apparatus for doors includes a door-like driven body, a conductive
rail having an inverted T-shaped configuration serving as a
secondary member of a linear motor, two travelling bodies being
supported upon a base portion of the conductive rail by means of
first rollers, and a primary coil of the linear motor and second
rollers disposed upon side surfaces of the unit travelling
bodies.
[0004] A drawback with the elevator car door suspension assemblies
of the known types is instability problems and increased
installation and maintenance cost.
SUMMARY OF THE INVENTION
[0005] The present invention concerns an apparatus for the
operation of suspended doors. A door suspension assembly includes a
ferromagnetic flat plate horizontally extending from a support rail
adapted to be attached to a door frame above a doorway or entrance
portal. Two supporting blocks each have an opening in which a
cylindrical bearing with an axial hole is located. The supporting
blocks are attached to a door panel. Connectors extend downwardly
from the flat plate and support a tube that extends through the
holes in the bearings. A magnet array is supported by an upper
plate attached to upper ends of the supporting blocks with a small
magnetic gap between the magnet array and the flat plate such that
the magnet array generates a magnetic force lifting the supporting
blocks and the door panel. A primary of a linear motor is attached
to the upper plate between the supporting blocks and cooperates
with a secondary located in the interior of the tube to move the
door panel relative to the flat plate.
[0006] If two door panels are used to provide center opening, each
door panel can be suspended in the manner described with the
support rail and flat plate extending across the doorway to the
extend required to provide adequate door travel.
[0007] One of the advantages of a door suspension assembly
according to the present invention is that it can be easily and
inexpensively manufactured and easily and quickly installed.
DESCRIPTION OF THE DRAWINGS
[0008] The above, as well as other advantages of the present
invention, will become readily apparent to those skilled in the art
from the following detailed description of a preferred embodiment
when considered in the light of the accompanying drawings in
which:
[0009] FIG. 1 is a schematic view of two door panels with a door
suspension assembly for an elevator car according to the present
invention;
[0010] FIG. 2 is a fragmentary schematic front elevation view of
the door suspension assembly for one of the doors shown in FIG.
1;
[0011] FIG. 3 is a side elevation view of the door suspension
assembly shown in FIG. 2;
[0012] FIG. 4 is a side elevation view similar to FIG. 3 of a
second embodiment of the door suspension assembly according to the
present invention;
[0013] FIG. 5 is a schematic perspective view of the bearing shown
in FIG. 3;
[0014] FIG. 6 is a cross-section of a portion of the tube shown in
FIG. 1 showing the secondary of a motor for said door suspension
assembly according to the present invention;
[0015] FIG. 7A is a top plan view of a door suspension assembly
shown in FIG. 1; and
[0016] FIG. 7B is a schematic front elevation view of the door
suspension assembly shown in FIG. 7A.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0017] A door suspension assembly according to the present
invention is shown in FIG. 1 and includes a support means or rail
support 1, intended to be attached to a crosspiece of a door frame
above the doorway or entrance portal. The system may be applied to
doors, windows, opening portions as doorways of industrial
buildings, houses, elevator cars, vehicles and the like.
Preferably, the rail support 1 has an I-profile, or an L-profile,
or a T-profile.
[0018] The rail support 1 includes or supports a substantially flat
ferromagnetic plate 2 extending in a horizontally disposed plane.
Attached to the rail support 1 at a lower surface of the plate 2
are two downwardly extending, spaced apart connectors 3 and 4
supporting opposite end portions of a rail 5 which preferably is
substantially cylindrical shaped having the form of a hollow tube,
e.g. made of non-magnetic stainless steel. The tube 5 and/or the
flat plate 2 extend at least approximately the length of an
associated door or have approximately the same length as the
required door travel. A further connector 6 may be provided
extending downwardly from the rail support 1 for holding a center
of the tube 5.
[0019] As shown in FIG. 1, the door suspension assembly includes
two guide means each having a pair of supporting blocks 7 and 7'
for suspending two door panels 12. Referring to FIGS. 2 to 4, each
of the blocks 7 and 7' has a recess or opening 8 and 8'
respectively in which the tube 5 is introduced. Attached to a lower
or bottom surface 9 of one of the supporting blocks 7 is a first or
lower plate 10 with connection means 11 (FIG. 3) from which a door
or the door panel 12 is suspended. The connection means 11
preferably includes screws or other types of fastener for
attachment to the door panel 12. The door panel 12 is attached to
the associated supporting block 7' in a similar manner and a second
door panel 12 is suspended in a similar manner from the other pair
of supporting blocks.
[0020] An upper or top surface 13 of the supporting block 7 is
attached to an end area of a lower surface of a second or upper
plate 14 whereas the supporting block 7' is attached to the other
end area of said upper plate 14 in a similar manner. A primary 15
of a linear motor is attached to the lower surface of the upper
plate 14 via a connecting means 16. Typically, the motor primary 15
includes a cylindrical type of winding. Preferably, the primary 15
is placed in the space between the blocks 7 and 7'. The secondary
of the linear motor is accommodated in an interior of the hollow
tube 5 as described below.
[0021] A magnet array 17 is also attached to the second plate 14 on
an upper surface thereof. The magnetic array 17 may include rare
earth permanent magnets, such as neodymium-iron-boron (NdFeB),
cobalt, samarium or cheap hard permanent ferrite magnets disposed
with alternating magnetic polarities. Accordingly, the door
suspension assembly functions as a magnetic unit including the
supporting blocks 7 and 7', the lower plate 10, the upper plate 14,
the motor primary 15 and the magnet array 17 attached to the plate
14. Naturally, the primary 15 also has an opening 18 (FIG. 2) which
is coaxial with the openings 8 and 8' of the blocks 7 and 7' so
that the tube 5 can traverse all the openings.
[0022] Accommodated in the opening 8 of each supporting block 7
there is a bearing or bushing 19, like a linear plain bushing or a
linear ball bushing, located in the air gap of the support block 7
between the tube 5 and a wall 20 (FIG. 3) of the opening 8 (FIG.
2). As seen in FIGS. 3 to 5, the bushing 19 is substantially a
cylindrical body with a longitudinally extending central hole 21
for receiving the tube 5. Preferably, the bushing 19 is a guide
made from a sliding synthetic material; for example, a plastic
material such as the "iglide J" bearing available from igus, inc.
of E. Providence, R.I., or the "FluoroNyliner" bearing available
from Thomson Industries, Inc. of Port Washington, N.Y., or a linear
ball bushing, for example of the Thomson "Super Smart" type.
[0023] The magnet array 17 generates a magnetic force lifting the
plate 14 and hence the attached blocks 7 and 7' supporting the door
12. The magnet array 17 is constructed to cancel the most of the
weight of the door panel 12. This passive magnetic suspension of
the door 12 reduces dramatically the radial force applied to the
bearings 19, as well as the overall friction in the system and the
maximum required force of the motor. The magnetic attraction force
between the magnet array 17 and the plate 2 is independent of the
action of the tubular linear motor, i.e. with or without currents.
It means that the passive magnetic suspension allows the door 12 to
open faster, noiseless and maintenance-free, the motor and an
additional converter to be smaller in size and the life of the
linear bearings 19 to increase due to the load reduction. When the
motor is active, the bushings 19 slide along the tube 5. The
bearings 19 guide the motor primary 15 sliding along the tube 5 in
case that the door weight is not fully suspended by the magnetic
force.
[0024] In the alternate embodiment according to FIG. 4, the door
panel 12 is suspended with a small eccentricity relative to the
axis of the hollow tube 5 which is received in the hole 21. An
L-shaped sheet 22 of a synthetic material or metal covers the front
of the blocks 7 and 7', the primary 15 and the magnet array 17 for
aesthetic purposes.
[0025] The rail support 1 preferably supports both the fixed
ferromagnetic plate 2 and the fixed tube 5. As seen in FIGS. 1 and
2, the linear motor primary 15 is attached to the door or panel
door 12 via the connecting means 16, the plate 14, the blocks 7, 7'
and the strip 10. Thus the door 12 will be moved together with the
primary 15. Between the magnet array 17 and the bottom surface of
the plate 2 there is a small magnetic gap d (FIG. 3), e.g. of 1 to
2.5 mm.
[0026] Due to the relatively high attraction between the magnet
array 17 and the flat plate 2, it is convenient to use a rigid rail
support 1 so that no deflection and change in the air gap d
dimension can occur. This requirement is fulfilled by the hollow
tube 5 and the high stiffness of the flat plate 2.
[0027] The individual magnets of the array 17 may be disposed with
alternating polarity on a carrier as shown in FIGS. 7A and 7B. The
carrier may be a back iron 31. The array 17 may comprise segments
(not shown) intermediate to inset-mounted individual permanent
magnets, i.e. each sequence of magnetic elements comprises a flat
permanent magnet e.g. with the N polarity above, an optional
intermediate magnetic element, a flat permanent magnet with the S
polarity above and an optional intermediate magnetic element. The
width of the intermediate segments may be smaller than that of the
individual permanent magnets. Preferably, the back iron 31 is
formed from a soft magnetic material such as mild steel, preferably
having a relative high permeability .mu..sub.r>>1. The
intermediate magnetic elements may be flat elements of mild iron or
steel, plates of ferrite, preferably but not exclusively soft
ferrite. The individual permanent magnets and/or other optional
intermediate elements may be glued to the back iron 31. As
illustrated in FIG. 6 and FIG. 7B, the array 17 may be supported by
the non-magnetic plate 14. The non-magnetic plate 14 may be formed
of aluminum or stainless steel, for example.
[0028] The secondary of the linear motor includes a plurality of
ring type permanent magnets such as magnets 23 and 24 shown in FIG.
6 that are accommodated in the interior of the hollow tube 5.
Between each pair of the magnets 23 and 24, which preferably have a
diametrically enhanced anisotropic direction of magnetization 25,
other cylindrical pieces 26 of non-magnetic material and/or soft
iron may be located. Note that for rod magnets the direction of
magnetization would point to the right for the magnet 23 and to the
left for the magnet 24. The actual sense of magnetization of the
ring or rod magnets depends of the type of motor used. The motor
primary 15 and the motor secondary 27, which are separated by an
air gap, produce the thrust to drive the door panel 12. This air
gap is substantially a wall thickness D of the hollow tube 5. As
usual, the primary 15 may be supplied with electrical current from
an electronic controller (not shown) that also controls the speed
of the motor. Because of the tubular linear motor configuration,
the normal force between the motor primary and the motor secondary
is very well balanced. There is no additional guidance, such as
roller, for the door panel 12 as required by a conventional linear
motor door. However, a lower guiding joint 28 (FIG. 1) for the door
or door panel 12 may also be used.
[0029] The position control of the door suspension assembly
according to the present invention may be achieved by sensors
comprising a moving element 29 and a fixed device 30 (FIG. 1)
arranged according to the prior art or by any other standard
positioning system.
[0030] The tubular linear motor is typically a permanent magnet
tubular linear synchronous motor (PM-TLSM) according to the prior
art. As an example, the linear motor elevator door will be based on
a center-opening door system, and be driven by two PM-TLSMs
separately. Therefore, the elevator door will operate with a very
simple mechanical structure. However, the tubular motor can also be
replaced by other types of motors, such as FLIMs/TLIMs or
FLRMs/TLRMs etc. (wherein F means flat, T tubular, L linear, I
inductance, R reluctance and M motor).
[0031] The tube 5 should be mounted on the blocks 7 and 7' prior to
attachment to the connectors 3, 4 and 6. However, in another
embodiment of the present invention the guide means 7 and 7' and/or
the bearing 19 may also have a radial opening instead of the hole
21.
[0032] A simplified embodiment of the invention includes only the
disclosed magnetic suspension, so that it can be fitted to the
elevator hoistway door. This means that the motor primary can be
replaced by a non-magnetic mechanical support with two linear
guides, and the motor secondary can be replaced by any tube or rod
or rail without magnets inside.
[0033] If the guide means 7 and 7' are made from a sliding
synthetic material, for example the igus "iglide J" plastic
material, the bearings 19 may be eliminated, and in this case the
diameter of the opening 8 should be smaller, specifically, it must
fit the tube or other equivalent element 5. Generally speaking, the
guide means may include or may not include the bearing 19.
[0034] Other advantages of the system according to the present
invention are that a high reliability can be achieved due to the
great reduction in the number of parts in comparison with the prior
art systems and the use of nearly maintenance-free components; the
volume of the motor and the inverter can also be reduced; extra
heat generated in the primary can be avoided; no special bearings
are needed to keep the motor air gap constant, avoiding so
stability and maintenance problems; and additional flexible ropes
and wheels are not needed.
[0035] In accordance with the provisions of the patent statutes,
the present invention has been described in what is considered to
represent its preferred embodiment. However, it should be noted
that the invention can be practiced otherwise than as specifically
illustrated and described without departing from its spirit or
scope.
* * * * *