[0001] The present invention relates to elevator car door operating systems and, more particularly,
to means for supporting and housing the same.
[0002] In conventional elevator systems, elevator car doors are selectively opened and closed
by a rotary electric motor driving a mechanical assembly, which typically includes
a plurality of moving parts such as gear boxes, a set of drive arms, linkages and
cams. The rotary electric motor is typically enclosed in a motor housing and secured
to the elevator car by means of a flange or mounting feet. A major drawback in existing
elevator car door systems is their susceptibility to misalignments, which require
frequent adjustments that result in high maintenance costs. Also, the misalignments
degrade the pertormance of the system such that door opening and closing functions
are not consistently smooth.
[0003] A linear motor driven door system provides an alternative to the existing electro-mechanical
system. However, packaging linear motor driven systems is challenging. A typical linear
motor for driving elevator car doors includes either a motor secondary or a motor
primary that extends the length of the elevator car door travel. Housing and supporting
such long motor parts becomes expensive and adds significant weight to the moving
elevator car.
[0004] Another problem encountered in the use of linear motors on elevator car doors is
misalignment between the moving and stationary parts of the linear motor. Maintaining
a constant clearance between the parts of the motor is critical to the performance
and efficiency of the motor. Usually, a housing of the moving part of the motor is
fixed to the elevator car door and moves therewith and a housing of the stationary
part of the motor is attached to the elevator car by means of a first bracket. The
door, with the moving part of the motor attached thereto, is movably supported by
a second bracket. In order to maintain proper clearances between the moving and stationary
parts of the motor, precise tolerances must be maintained between the first bracket
securing the stationary part of the motor to the elevator car and the second bracket
which affects the position of the door having the moving part of the motor secured
thereon.
[0005] Viewed from one aspect the present invention provides an elevator car door operating
system for driving an elevator car door, comprising:
a door hanger suspending said elevator car door therefrom, said door hanger having
a plurality of rollers attached thereto;
a linear motor primary fixedly attached to said door hanger;
a motor secondary extending the length of the door travel; and
a system housing supporting and housing said motor secondary and including a track
for said rollers to ride on.
[0006] The system housing may also support a termination box with moving flexible cables,
and a positioning and synchronization system.
[0007] An embodiment of the invention will now be described by way of example and with reference
to the accompanying drawings, in which:-
FIG. 1 is a cut-away schematic perspective view of an elevator car door system supported
by a multi-functional system housing, according to the present invention; and
FIG. 2 is a schematic cross-sectional side view of the system of FIG. 1, taken along
the line 2-2.
[0008] Referring to FIG. 1, an elevator car door operating system 10 for opening and closing
a pair of elevator car doors 12 includes a multi-functional system housing 14 that
houses and supports all parts of the elevator car door operating system. The system
housing 14 comprises integrally formed upper and lower housing portions 16 and 18.
The lower housing portion 18 includes a protruding bend portion 20 to support a track
22. The track 22 extends the length of the door travel and is bolted to the protruding
bend 20 by means of bolts 24. The track includes an upper roller surface 28 and a
lower roller surface 30.
[0009] Referring to FIG. 2, a plurality of hanger rollers 34, that are attached to each
door hanger 36, come into contact with the upper roller surface 28. A plurality of
upthrust rollers 38, that are also attached to each door hanger 36, have a minimal
clearance from the lower roller surface 30. The lower housing portion also supports
a synchronization and positioning system 39.
[0010] The upper housing portion 16 includes an integrally formed top flange 40, and houses
a linear motor secondary 42. The motor secondary 42 is attached to the housing 16
by means of a plurality of joints 44. Each joint 44 includes a standoff to provide
spacing between the housing 16 and the motor secondary, and a swivel to allow flexibility
of the motor secondary 42 about each joint 44.
[0011] The upper housing portion 16 also houses a termination box 50 with a pair of moving
flexible cables 52, as best seen in FIG. 1. The termination box 50 is mounted centrally,
underneath the top flange 40, with each flexible cable 52 originating from the termination
box 50 and terminating at a respective motor primary 54. Each motor primary 54 is
fixedly attached to a respective one of the door hangers 36. Each motor primary includes
a primary winding 56 and a backiron 58 spaced apart by a plurality of spacers 60 to
define a magnetic air gap 62 therebetween.
[0012] In operation, the moving flexible cables 52 transmit energy from the termination
box 50 to the respective motor primaries 54. As each motor primary 54 travels across,
the motor secondary 42 fits within the magnetic air gap 62 of the motor primary 54.
The motor primary cooperates with the motor secondary to generate thrust forces. The
thrust forces move the motor primaries and the respective door hangers to which the
motor primaries are attached. As the door hangers travel, opening and closing the
elevator car doors suspended therefrom, the hanger rollers 34 glide atop the upper
roller surface 28 of the track 22. The upthrust rollers 38 come in contact with the
lower roller surface 30 of the track 22 in the event the doors are subjected to upward
thrust.
[0013] The multi-functional system housing 16 of the present embodiment not only supports
the rollers of the door hangers, but also functions as an integral housing for the
motor secondary. The housing eliminates the need for an additional separate housing
to shield and support the motor secondary. The housing provides rigid support to the
motor secondary and has the motor secondary flexibly mounted thereto. Also, the housing
shields the motor secondary from external elements and includes the top flange to
prevent hoistway debris or drippage from reaching the motor secondary. By eliminating
the need for a separate motor secondary housing, the present embodiment saves the
cost of an additional piece, the time to install it, and the excess weight.
[0014] Also the present embodiment, having the housing of the motor secondary integral with
the track for the door hangers, reduces the potential for misalignment between the
motor primaries and the motor secondary.
[0015] The housing also supports the termination box 50 and the positioning and synchronization
system 39.
[0016] In a preferred embodiment the system housing is formed from steel.
[0017] It will thus be seen that the present invention, at least in its preferred forms,
provides a high performance operating system for opening and closing elevator car
doors; and furthermore ensures proper alignment between parts of a linear motor driving
the elevator car door operating system; and furthermore reduces the overall weight
of the elevator car door operating system; and furthermore minimizes the number of
parts necessary to support the elevator car door operating system.
1. An elevator car door operating system for driving an elevator car door (12), comprising:
a door hanger (36) suspending said elevator car door therefrom, said door hanger having
a plurality of rollers (34,38) attached thereto;
a linear motor primary (54) fixedly attached to said door hanger;
a motor secondary (42) extending the length of the door travel; and
a system housing (14) supporting and housing said motor secondary and including a
track (22) for said rollers to ride on.
2. A system according to claim 1, wherein said system housing (14) is made of steel.
3. A system housing (14) for an elevator car door operating system for driving an elevator
car door between open and closed positions, said system housing comprising:
an upper housing portion (16) supporting and housing a motor secondary (42); and
a lower housing portion (18) integrally formed with said upper housing portion, said
lower housing portion including a track (22) to support a plurality of rollers (34,38)
mounted on a door hanger (36) for suspending a said door.
4. A system housing according to claim 3, which also supports a synchronization and positioning
system.
5. A system housing according to claim 3 or 4, which also supports a termination box
(50) and a plurality of moving flexible cables (52).