Note: Descriptions are shown in the official language in which they were submitted.
CA 02219002 1997-10-21
r t
BACKGROUND OF THE lNv~N-lloN
1. Field o~ the Invention
The present invention relates to a swinging/sliding door for
vehicles including
a) at least one door leaf;
b) a support rail fixedly mounted in the vehicle for
supporting the door leaf;
c) a carriage longitu~inally slidably mounted on the
support rail;
d) a pivotable support mechanism, possibly forming an
articulated parallelogram, for connecting the door lea~
to the carriage;
e) a guide rail fixedly mounted in the vehicle, wherein a
guide pin connected to an element of the support
mechanism travels in the guide rail and determines the
angular position o~ the support mechanism in this
manner;
f) a linear drive for effecting the movement of the door
leaf or carriage along the support rail; wherein
g) the linear drive acts on an engagement point of the
carriage.
CA 02219002 1997-10-21
,
2. Description of the Related Art
A construction of the above-described type is disclosed in
EP O 643 190 A2. In this construction, the reaction torque o~
the recluction gear unit of the drive motor through a coupling rod
is used for the purpose of outwardly moving at the beginning of
the opening movement a door support pipe which causes the
adjusting.movement o~ the side closing edge of the door leaf and
pivoting inwardly the door support pipe at the end of the closing
movement.
A similar construction is known from DE 43 16 253 A1 in
which the coupling rod assumes a position beyond dead center in
order to securely hold the door support pipe in its respective
angular position.
A somewhat different construction is disclosed in DE 32 31
181 C2. However, concerning the type of drive it is merely
mentioned that the drive acts by means o~ a rigid arm on the door
leaf. This is necessary in order to handle the dynamic and
kinematic problems during the pivoting of the articulated
parallelogram.
CA 02219002 1997-10-21
,
DE 34 19 338 C2 discloses a linear drive for a door in the
form of a revolving endless rope or belt drive in which the
diameter of the guide rollers of the rope or belt drive is used
for the adjusting movement of the door. The hinge point of the
door leaf at the revolving cLrive travels for approximately 90~
together with the guide dislc and this causes the door to be
pulled into alignment with t:he car body or to be moved outwardly
during opening. However, in view of this type of drive, the
actual guide ~or the door (which is not discussed in this
reference) must be constructed in accordance with a different
principle than in the reference mentioned first.
The reference mentionecl last has the advantage over the
refere1lce mentioned first that the drive produces at the end o~
the closing movement and at the beginning of the opening movement
directly a force component which rein~orces the swinging movement
taking place in this position of the door. However, because of
the load acting on the belt drive in which the connecting f itting
for the door leaf must partially travel around the roller, this
solution is susceptible to trouble and is subj ect to wear
quickly .
CA 02219002 1997-10-21
SUMMARY OF THE lNv~N-LlON
Therefore, it is the primary object of the present invention
to provide a swinging/sliding door for vehicles of the above-
described type in which the disadvantages described above are
avoided while the advantages are maintained. Thus, a door of the
above-described type is to be provided which is easy to maintain
and adjust and which meets the object of the invention with
simple and inexpensive structural components.
In accordance with the present invention, the engagement
element for the carriage is moveable between two positions,
wherein one position corresponds to the outwardly swung, open
position of the door leaf and the other position corresponds to
the inwardly swung, closed position of the door leaf, and wherein
the movement of the engagement element from one position to the
other position causes a torque to act on a hinge point of the
support mechanism on the side of the carriage for effecting the
inward and outward movements or for at least substantially
reinforcing the movements.
In accordance with a first preferred embodiment of the
invention, the linear drive is a revolving endless belt, a chain,
or the like, which revolves at the carriage about a roller which
. CA 02219002 1997-10-21
forms the engagement element, wherein the roller is connected or
is in operative connection with a pivot axis of the support
mechanism. In accordance with a second preferred embodiment of
the invention, the linear drive is a spindle which interacts with
a spindle nut which is rotatably mounted between two stops o~ the
carriage and forms the engagement element in this manner, wherein
the spindle nut is in operative connection with the rotational
axis of the support mechanism on the side of the carriage through
a gear unit, a ~riction wheel unit, a belt or the like.
In accordance with a third advantageous ernbodiment of the
invention, the linear drive is an endless belt or the like as in
the ~irst embodiment, but the support mechanism is not an
articulated parallelogram but a simple pivot arm, so that the
entire construction can be substantially more compact.
The various features of novelty which characterize the
invention are pointed out wif_h particularity in the claims
annexed to and ~orming a parl_ o~ the disclosure. For a better
understanding of the invention, its operating advantages,
speci~ic objects attained by its use, reference should be had to
the drawing and descriptive rnatter in which there are illustrated
and described preferred er~o(1iments of the invention.
, CA 02219002 1997-10-21
BRIEF DESCRIPTION OF THE DRAWING
In the drawing:
Figs. 1 to 5 are sectional partial views of a first
embodiment o~ a swinging/sliding door according to the present
invention showing different closing stages of the door during the
closing movement thereo~;
Fig. 6 shows a detail of a second embodiment of a door
according to the present invention with a spindle drive;
Figs. 7-9 are schematic illustrations o~ constructions
according to the present invention for locking the closed
position of the door leaf in the area of the side closing edge of
the door; and
Figs. 10-12 are schematic views of a third embodiment of the
invention in which the support mechanism does not form an
articulated parallelogram.
, CA 02219002 1997-10-21
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Fig. 1 o~ the drawing is a horizontal sectional view o~ the
swinging/sliding door accord.ing to the present invention showing
the elements which are significant with respect to the invention.
A door lea~ 1 is supported on a carriage 6 by means of an
articulated parallelogram ha.ving pivot axes 2 and 3 ~ixed to the
door and pivot axes 4 and 5 ~ixed to the carriage. The carriage
6 travels on a support rail 7 which is fixedly mounted in the
vehicle. It is also conceivable to have cases in which the
support rail 7 is mounted in. the car body so to be axially fixed
but rotatable about its axis.
The respective angular position o~ the articulated
parallelogram 2, 3, 4, 5 which depends on the position o~ the
carriage 6 on the support ra.il 7 is determined by a control
roller 8 which travels in a guide rail 9 and is connected in an
appropriate m~nner to the articulated parallelogram; in the
illustrated embodiment, the control roller 8 is connected to the
connecting arm between the a.xes 2 and 4.
The door drive is constructed as a revolving endless toothed
belt 10 which travels arouncL two stationary guide rollers 11, 12
and at the carriage 6 arouncL two guide rollers 13, 14 connected
, CA 02219002 1997-10-21
to the carriage and around a guide roller 15 which is connected
to the axis 4 o~ the articulated parallelogram so as to rotate
with the axis 4. The drive of the toothed belt 10 is e~ected by
a motor acting on one of the two guide rollers 11, 12, wherein a
gear unit may be arranged therebetween, however, such a gear unit
is known in the art and does not constitute a part o~ the
invention and, there~ore, does not require to be explained in
detail herein.
Since the angular position of the articulated parallelogram
2, 3, 4, 5 is determined by the guide roller 8 in the guide rail
9, a tensile ~orce applied to the revolving toothed belt 10 in
the position shown in Fig. 1 results in a displacement of the
carriage 6 and, thus, the door 1. The position shown in Fig. 1
corresponds to the end position during opening o~ the door; by
using appropriate sensors and control circuits which are known in
the art and not part o~ the invention, only a closing movement o~
the door leaf 1 is provided in the position illustrated in Fig.
1.
During the closing movement, the carriage 6 ~inally reaches
the position shown in Fig. 2 which constitutes the end of the
purely translatory movement o~ the door lea~ 1 and in which the
swinging movement starts which causes the door lea~ 1 to be swung
CA 02219002 1997-10-21
into its end position in which the door leaf 1 is in the door
opening in alignment with the car body. When reaching this
position, the advantages achieved by the invention become
effective: by pulling on the revolving toothed belt 10 in the
direction of arrow 16, a torque in the counter-clockwise
direction is applied on the guide roller 15 and, thus, on the
articulated parallelogram 2, 3, 4, 5 which reinforces pivoting o~
the articulated parallelogram 2, 3, 4, 5 and, thus, swinging of
the door leaf 1.
As illustrated in Figs. 3 and 4, which show the further
swinging movement of the door leaf 1, the effect according to the
present invention becomes particularly apparent and strong if, in
the area ln which the guide roller 8 is located during the
swinging movement, the guide rail 9 extends concentrically
relative to the pivot axis 4 of the articulated parallelogram
which is already standing still relative to the vehicle.
Fig. 5 of the drawing shows the completely closed position
of the door leaf 1. As is apparent from Fig. 5, the articulated
parallelogram 2, 3, 4, 5 assumes the angular position which
corresponds to the closed position of the door.
, CA 02219002 1997-10-21
Opening of the door tak:es place analogously to the described
closing in the reverse sequence: by applying a tensile force
against the direction o~ arrow 16 shown, ~or example, in Fig 3,
a torc~ue directed in the clockwise direction acts on the guide
roller 15 which is in operative connection with the articulated
parallelogram 2, 3, 4, 5 and causes a pivoting of the articulated
parallelogram and, thus, out.ward swinging o~ the door leaf 1.
Also, the guide roller 8 is displaced in the guide rail 9 in
the curved portion of the guide rail 9 which corresponds to a
rotary movement about the pivot axis 4 of the articulated
parallelogram which is still standing still relative to the
vehicle. When the roller 8 reaches during the rotary movement
the straight portion of the guide rail 9, this causes the end of
the rotary movement o~ the pivot axis 4 and, thus, also fixing o~
the guide roll 15 with respect to rotation, thus, of the toothed
belt 10 at the carriage.
Due to the reaction ~orce which is being built up as a
result, the carriage 6 is moved along the support rail 7 and
causes the now fully outwardly swung door lea~ 1 to carry out the
translatory movement in opening direction. This movement is
stopped when the position shown in Fig. 1 is reached in which the
CA 02219002 1997-10-21
various sensors determine that the position has been reached and
cause the drive to be switched off.
The embodiment described above can be modified in various
ways. For example, it is not necessary that the toothed belt 10
travels around a guide roller 15 which is coaxially and fixedly
connected to the pivot axis 4. It is possible to provide a guide
roller which acts on the pivot axis 4 through a gear wheel unit,
a friction wheel unit or a belt drive, wherein this makes it
possible to apply a different efficiency and a different torque
during opening and closing t;han those predetermined by the motor
and the gear unit flanged thereto. It is also possible to have
the toothed belt slide past an appropriately selected gear wheel
by means of a contact plate in the form of a type of pinion,
however, this solution is not preferred because of the increased
wear of the toothed belt.
In accordance with anot:her solution, a combination of the
carriage movement and the p~voting movement of the articulated
parallelogram takes place during closing which makes it possible
to produce any desired opening and closing end movement. For
this purpose, in the area in which the roller 8 is located when
the door is in the closing end position, the shape of the guide 9
must merely be adapted accordingly.
, CA 02219002 1997-10-21
When constructing two-leaf doors, it is simple to adapt the
invention accordingly: For example, it is possible to provide
another mirror-inverted device by constructing the guide roller
12 as a gear wheel and with only one drive. However, it is also
possible to use a toothed belt 10 which extends over the entire
door opening, wherein each door lea~ is driven by one o~ the two
portions of the toothed belt 10; by providing a twisted
arrangement of the toothed belt 10, possibly in combination with
inclined guide rollers 11, 12, it is possible to arrange the
guide rollers 13, 14, 15 mounted on the carriage on the two
carriages in almost the same plane without inter~ering with the
other portion of the toothed belt.
I~ is also not necessarily required that the revolving drive
means 10 is a toothed belt i~ such is pre~erred ~or reasons o~
cost and wear. 0~ course, it is possible to use ropes, ch~;n~ or
other drive elements of this type, wherein additional tensioning
members may be provided, ho~ever, these ~eatures are not part o~
the invention and are not explained herein.
The arrangement o~ a revolving drive means also has the
advantage that, during periodically recurring maintenance
operations, the drive means can be moved by a certain distance,
so that the highly stressed points "travel" along the entire
13
CA 02219002 1997-10-21
drive means during the total operating time, so that the stress
is uniformly distributed and, thus, the service life is
substantially increased.
In the second embodiment of the configuration according to
the present invention, a spindle drive is used. Fig. 6 of the
drawing shows a carriage 6 which, as is the case in the first
embodiment, travels along a support rail 7 and is arranged on the
pivot axis 4, 5 of an articulated parallelogram on the side of
the carriage. In the illustrated embodiment, the pivot axis 5
has a bevel gear 17 which meshes with a bevel-type pinion 18
which, in turn, is mounted on a spindle nut 19. The spindle nut
19 is connected so as to be rotatable but not displaceable to an
arm 20 of the carriage 6. The spindle nut 19 travels on a
spindle 21 which constitutes the linear drive element which, in
the first embodiment, is formed by the toothed belt 10.
The m~nn~r of operation of the embodiment according to Fig.
6 is completely analogous to that of the embodiment of Figs. 1-5:
in the closing end position shown in Fig. 6, during opening the
rotation of the spindle 21 transmits a torc~ue to the spindle nut
19 which transmits the torque through the bevel gears 18, 17 to
the articulated parallelogram in a clockwise direction and causes
the door leaf to be swung out. When the pivoting movement of the
, CA 02219002 1997-10-21
articulated parallelogram is stopped by the guide device (8, 9 as
shown in Fig. 1, not shown in Fig. 6 for reasons of clarity), the
resulting reaction forces cause the carriage 6 to be moved in
opening direction, i.e., toward the right as seen in Fig. 6. The
closing of the door takes place analogously.
The second embodiment of the invention can also modified in
various ways. For example, instead of the bevel gear unit, a
less expensive crown gear unit can be used or also a friction
wheel combination. Fig. 6 further shows that it is not necessary
that two sides of the articulated parallelogram extend parallel
to the support rail 7; of course, this is true for all
embodiments of the invention.
The construction of the swinging/sliding door according to
the present invention has advantages in addition to the
advantages described above because the configuration according to
the present invention makes it easily possible to hold the side
closing edge 22 of the door in the closed position with almost
any selectable forces. Three preferred developments are
illustrated in the drawing.
Fig. 7 shows a door construction according to the present
invention in which the door leaf 1 is guided in the area of the
,, ~ CA 02219002 1997-10-21
side closing edge 22 and is held in the closed position. This is
extremely desirable particularly in high-speed trains because of
the negative pressures occurring between trains when two trains
pass each other. In order to achieve this goal, a guide means 23
is provided which interacts with rollers 24 or the like which are
arranged on a pivot arm 25. The pivot arm 25 is pivotable about
an essentially vertical axis 26 and secures the outwardly moved
position of the door leaf in the area of the side closing edge 22
in this manner. In conventional doors, the pivot lever 25 is
forced to participate in the movement of the door leaf and
secures the outward position only in order to prevent a collision
between the door leaf and the frame which forms a fixed part of
the vehicle.
In accordance with other constructions, the pivot lever 25
is under the influence of a spring which, depending on the type
of application, has the purpose of moving the pivot lever into
the closing position or the opening position. In high-speed
trains, it is also known to provide a separate pivoting drive
which controls and secures t,he angular position of the pivot
lever 25 in dependence on the door control and independently of
the actual door drive.
CA 02219002 1997-10-21
In accordance with the present invention, the guide roller
11, which is located in the area o~ the side closing edge, is
provided with an appropriate drive element and a locking arm 27
which, when the closing end position of the door leaf 1 has been
reached, engages with a bolt Z8 in a groove 29 of the pivot lever
26 and pushes and then secures the pivot lever 26 at ~irst in the
closed position
It is worth mentioning in connection with the embodiment
shown in Fig. 7 that the guide rail 9 for the articulated
parallelogram 2, 3, 4, 5 is constructed di~erently ~rom that o~
the embodiment o~ Figs. 1-5 and assumes a di~erent position
relative to the door drive, while the direction of movement of
the toothed belt 10 is not changed and, thus, the respective
directions of rotation of the guide rollers 11, 12 are also not
changed. In this embodiment, during the pivoting movement, the
guide roller 15 o~ the toothed belt 10 and, thus, the pivot axis
4 are located essentially in the center of the bent portion of
the guide rail 9 of the roller 8.
At the end o~ the closing end movement, the locking lever 27
rotates against the direction o~ the guide roller 11 which can be
easily effected, for example, by a planetary gear unit. When the
door drive is flanged directly at the area of the guide roller
, 11 , CA 02219002 1997-10-21
11, the pivoting movement of the locking lever 27 is preferably
derived as a reaction movement of the motor torque from the
rotatably mounted drive.
Fig. 8 of the drawing shows a further development of the
locking means in the area of the side closing edge, wherein the
guide unit 8, 9 again has the form as described in connection
with the first embodiment. In the embodiment of Fig. 8, the
pivot lever 25 has a guide slot 30 which interacts with a
corresponding roller of an intermediate lever 31 The
intermediate lever 31 is in operative connection with the locking
lever 27, wherein the locking lever 27, in turn, interacts with
the actual drive ~or the door movement which acts on the guide
roller 11.
The control by means of a guide slot makes it possible, in
addition to securing the door leaf 1 in the area o~ the side
closing edge 22, to also support the outwardly adjusting movement
because the guide slot 30 permits the application o~ forces in
both directions perpendicularly of the longitudinal extension of
the guide slot.
In that case, by providing an appropriately curved
configuration of the guide slot 30, locking can be carried out
18
, CA 02219002 1997-10-21
even when the drive becomes inoperative because, no matter how
high the ~orces are which act on the door lea~ 1, an outward
movement of the side closing edge of the door leaf 1 is not
possible as a result of an appropriately selected shape of the
guide slot 30 in cooperation with the intermediate lever 31. For
safety reasons, such as sel~-locking con~iguration is pre~erred
in many types of application.
In accordance with another modification of this embodiment
as shown in Fig. 9, the pivot lever 25 is secured in the closed
position by moving its connecting arm 32 toward the locking lever
27 past a dead center point, so that, no matter how high the
forces acting on the door leaf 1 are, an opening of the door leaf
1 is not possible without actuating the drive. Fig. 9 again
shows this modification in the embodiment of the guide unit 8, 9
according to the present invention as shown in Figs. 1-5. The
dead center point is located where the connecting arm 32 travels
over the axis of the locking lever 27. As is the case in the
other embodiments, the locking lever 27 is preferably moved by
the reaction torque of the drive.
Figs. 10-12 show a modi~ied embodiment o~ the present
invention which is of particularly compact structural size. In
this embodiment, the support mechanism is only composed of a
19
, ,, , CA 02219002 1997-10-21
pivot arm 33 which is connected in an articulated manner to the
carriage 6 and to a support arm 34 attached to the door lea~,
wherein the pivot arm 33 is pivotable at the articulated
connections about a vertical axis each. The pivot arm 33 is
attached to a drive ar~L34, wherein the linear drive 10 acts on
the drive arm 35, and wherein the angular position of the arm
drive 35 and, thus, o~ the pivot arm 33 is determined by a guide
roller 8 which is guided in a guide rail 9 attached to the door.
As in the first embodiment of the invention, the linear
drive 10 is composed of a belt drive which is guided about guide
rollers 11, 11', 12, 12' with axes attached to the door ~rame,
wherein one roller, i.e. the roller 11 in the illustrated
embodiment, is driven through a gear unit 37 in the area of the
side closing edge of the door leaf 1.
Also, analogously to the embodiments of Figs. 7, 8 and 9, a
vertical axis 26 attached to the door ~rame, which may be, ~or
example, a door support pipe, iS provided. Attached to this axis
26 is a pivot lever 25 which supports the rollers 24 which travel
in a guide 23 of the door leaf 1.
The gear 37 is mounted so as to rotatable; a lug 36 is
pivotably mounted on the gear housing, wherein the other end o~
-
, CA 02219002 1997-10-21
the lug 36 is attached to the axis 26 and, thus, also to the
pivot lever 25.
The manner of operation of the construction according to
this modified embodiment of the invention is as follows:
Starting ~rom the upper illustration in Fig. 10 which shows the
door in the open state, closing is e~ected by rotating the gear
37, the roller 11 in a clockwise direction. The reaction torque
of the gear 37 is derived through its housing, the lug 36, the
pivot lever 25 and the rollers 24 and 39 to the guide 23, so that
the axis 26 is not rotated.
The toothed belt 10 moved by the driven roller 11 is
pivotably connected to the drive lever 35. Since the angular
position of this drive lever 35 relative to the carriage 6 is
determined by the roller 8 and its guide rail 9, the carriage and
all horizontally moveable parts of the door drive and of the door
are moved along the guide in order to close the door.
During this closing movement, the roller 8 is moved to that
location of the guide rail 9 where the guide rail 9 is curved, so
that the angular position of the drive lever 35 relative to the
carriage 6 changes. Since the drive lever is attached to the
pivot lever 33 so as to rotate therewith, this change in angular
,~ , CA 02219002 1997-10-21
position leads to an inwardly swinging movement of the door lea~
1. This inwardly swinging movement is reinforced by the reaction
torque of the gear 37 which still acts on the door support pipe
26.
The reaction torque increases with increasing pressure of
the door leaf 1 at the end of the closing movement against the
seals. Pivoting of the door support pipe 26 also has the result
that the lug 36 is rotated into the position beyond the dead
center shown in the lower illustration of Fig. 10, so that an
opening of the door is no longer possible even if the drive is
without power.
When the door is opened, the drive 6 seeks to rotate the
roller 11 in the clockwise direction which is not possible
because of the locking action, so that the reaction torque
rotates the lug 36 in the counterclockwise direction beyond the
dead center and, thus, acts on the door support pipe 26 in the
direction of the outward swinging movement.
In order to ensure that, prior to reaching the fully swung-
out position, no longitudinal displacement of the door leaf takes
place, an adjusting roller 33 is provided on the pivot lever 25,
wherein, in the closed position of the door, the adjusting roller
22
.~ . CA 02219002 1997-10-21
39 is received in a recess 40 of the door leaf 1 and, thus,
prevents a translatory movement of the door leaf. By rotating
the door support pipe 26 and the resulting change of position of
the pivot lever 25, the adjusting roller 39 is moved out of the
area of the recess 40 and the door leaf can travel past the
adjusting roller 39. In the opposite direction when closing the
door, this adjusting roller 39 ensures that the door leaf 1
cannot be swung in before reaching the correct position.
A possible emergency actuation of the door is schematically
indicated by a spring 38 con:nected to the gear housing, wherein
the spring can be used for o-vercoming the dead center position of
the door drive in the case of an emergency.
Instead of the mechanism in which the dead center position
is overcome, it is also possible to provide a guide slot
configuration, similar to the one shown in Fig. 8, so that it is
also ensured that the reaction torque of the gear or motor
supports the swinging movement of the door leaf 1 or the door
support pipe 26 also during opening.
In the case of doors having two leafs, the locking mechanism
for the side locking edge according to the present invention can
be utilized by using appropriate and conventional transmission
CA 02219002 1997-10-21
means ~or the drive or guide mechanism o~ the second door lea~;
of course, when familiar with the present invention, this does
not pose problems to those skilled in the field of the
manufacture of doors for transportation vehicles. The selection
o~ the devices to be used in the area o~ the side closing edge
depends on the intended e~ects and the field of application and
those skilled in the art can easily select the appropriate
devices in accordance with the specific requirements.
At any rate, it is a particularly pre~erred modi~ication o~
this embodiment that the movement o~ the locking lever 27 is
effected by the motor reaction torque and, thus, an additional
drive is not required. In addition to this, the derivation from
the motor reaction torque also results in an automatic sequence
o~ the individual phases of the movement without requiring
specific monitoring by sensors and an appropriate control o~
different drive units.
Of course, in the case of the second embodiment o~ the
present invention described above in which a spindle is used, it
is possible to derive the appropriate reaction torque ~or moving
a locking lever through a bevel gear or crown gear. This is also
possible when using a gear belt drive for the spindle with an
electric motor extending parallel to the spindle, however, in
, ,~ . CA 02219002 1997-10-21
that case, a support of the motor must facilitate the derivation
of an appropriate reaction torque.
Of course, it is possible to use the manner of moving and
securing the door leaf in the area of the side closing edge
according to the present invention independently of the use of
the basic concept of the present invention.
In the description and claims, the designation "engagement
element" is used in a general m~nn~r, for example, for the
contact friction between the toothed belt 10 and the guide roller
15 in the first embodiment, for the engagement of the gears 17,
18 in the second embodiment, and for the angular position of the
drive lever 35 in the third embodiment. It is also conceivable
to secure in the first embodiment the toothed belt 10 to an
extension of the connecting element of the pivot points 3 and 4
of the articulated parallelogram, which would also correspond to
an engagement point in the sense of the present invention.
The present invention can be modified in various ways. For
example, it is possible in the first embodiment to wind the
toothed belt around both piv-ot axes on the side of the carriage
in order to increase the torque which can be transmitted. The
possibility of acting on a different element of the articulated
, ,1 , CA 02219002 1997-10-21
parallelogram 2, 3, 4, 5 than on the pivot axes at the carriage,
has already been mentioned; when using an appropriate fork-shaped
drive element, this can be done without deflection o~ the toothed
belt 10. A drive element of this type can also be used in the
third embodiment of the invention.
Those elements which are conventional in the art and are not
directly part o~ the present invention are not described herein
~or reasons of clarity. Among these elements are, for example,
additional door guide means in the bottom area, sensors for
monitoring the door movement, emergency opening devices for the
case when the drive becomes inoperative, and special
configurations o~ seals, particularly in high-speed vehicles, and
the like.
While specific embodiments of the invention have been shown
and described in detail to illustrate the inventive principles,
it will be understood that the invention may be embodied
otherwise without departing from such principles.
