-
This invention relates to a control system for a closure such as a door and
in particular, but not exclusively to a control system for a vehicle door.
-
Controlling opening movement of vehicle doors is required to prevent
damage to the door and/or to a surface which the door comes into contact
with, for example the door of another vehicle when two cars are parked
next to each other.
-
It is already well known to employ a door check of the kind in which a
link in the form of strap adapted to be pivotally connected at one end to a
door frame is withdrawn through a housing mounted on a complementary
part of the door and has a stop at the other end to limit opening movement
of the door.
-
The movement of the link is typically subject to a restraining force which
may be provided by a spring loaded roller on one of the link and housing
and co-operable with the other of the link and housing to provide
frictional restraint to opening movement of the door.
-
The known door checks commonly allow the door to open up to a
maximum of 60° relative to the vehicle body and the door may be held in
one or two intermediate open positions, for example at 30° and 45° to the
vehicle body, by engagement of the spring loaded roller in complementary
recesses.
-
A disadvantage of the existing door checks of this type is that the door
can only be held open at pre-determined positions according to the
position of the end stop and any recesses for engagement with the spring
loaded roller.
-
It can often happen that such pre-determined positions do not correspond
to the extent to which the door can safely be opened without coming into
contact with an adjacent surface leading to the risk of damage if the door
is released at an open position in which it is not positively held. For
example, the door may open beyond the position at which it is released
due to the momentum of the force applied to open the door and/or by a
gust of wind if the door is released when stationary.
-
The number of intermediate hold open positions may be increased by
providing more recesses but the size and spacing of the recesses restrict
the angular spacing of the hold open positions that can be achieved. In
general, an angular spacing of 15-20° is the minimum that can be
obtained with this type of device.
-
The present invention has been made from a consideration of the
disadvantages aforementioned.
-
In particular, the present invention seeks to provide a control system for a
closure such as a door and in particular, but not exclusively a vehicle
door, which enables a wider range of hold open positions to be achieved
than permitted by existing door checks.
-
More especially, it is a preferred object of the invention to provide a
control system which allows relatively small adjustments to be made to
the hold open position of the closure.
-
Thus, the invention may permit the angular position of the closure to be
adjusted by a few degrees and the closure to be held in selected open
positions.
-
In this way, the hold open position of the closure can be finely adjusted
between closed and fully open according to the space available. As a
result, the opening movement of the closure can be adapted to the
requirements for a particular situation.
-
According to one aspect of the present invention there is provided a
control system for a closure mounted for movement relative to a frame
towards and away from a closed position, the control system comprising
means for releasably holding the closure in an open position, means for
monitoring force applied to the closure and movement of the closure, and
means for controlling the holding means in response to the monitoring
means.
-
By this invention, the control means is operable to release the holding
means allowing movement of the closure when the monitoring means
detects a pre-determined force applied to the closure, and to apply the
holding means preventing movement of the closure when the monitoring
means detects the closure is stationary or has slowed to a pre-determined
speed.
-
In this way, the open position of the closure can be adjusted as desired
according to the available space thereby reducing the risk of damage to
the closure from contact with an adjacent structure. As a result, the
closure can be opened to the extent permitted and held at that position
until it is desired to close the closure.
-
Preferably, the holding means is arranged to apply a braking force to
prevent movement of the closure, and the braking force is released to
allow movement of the closure when a pre-determined operating force is
applied to the closure.
-
The braking force may be applied by any suitable means, for example by
using devices employing friction, detents, hydraulics, pneumatics,
electro-magnets or ferro-fluidics.
-
In a preferred embodiment, opening movement of the closure is controlled
by a link arm configured to move through a device operable to apply the
braking force to the link arm. The link arm may include an end stop to
limit opening movement of the closure.
-
Advantageously, the monitoring means includes a device for sensing the
force applied to the closure and sending a signal to the control means
when the pre-determined force is applied, and a device for sensing
movement of the closure and sending a signal to the control means
according to whether the closure is stationary or moving.
-
Any suitable devices may be employed for this purpose. For example,
the force detector may comprise an electronic sensor such as a strain
gauge or load cell or a mechanical sensor for detecting movement of an
element against a pre-loaded spring. The movement detector may, for
example, comprise a proximity sensor or optical or magnetic sensor.
-
Preferably, the control means comprises a logic controller responsive to
signals from the monitoring means to control actuation of the restraining
means to releasably hold the closure in a selected position. The logic
controller may be programmable to control the function of the system
according to user requirements.
-
The restraining means may be operable to hold the closure in both open
and closed positions. Alternatively, the restraining means may be
operable to hold the closure in open positions only.
-
Preferably, latch means is provided for securing the closure closed in
place of or in addition to the restraining means. Where the closure is
secured closed by the latch means and the restraining means, the latter
may be released by actuation of the latch means to open the door, for
example by actuation of a latch operating handle. Where the closure is
secured closed by the latch means only, the restraining means may be
released in the closed position by additional input of a sensor to detect the
closure is closed, for example a "door closed" switch.
-
Advantageously, the control system includes means for applying a
constant braking torque to prevent unrestricted movement of the closure
when the restraining means is released. For example a friction device or
any other suitable means to control movement of the closure.
-
Preferably, the control system includes fail-safe means for over-riding the
restraining mean. For example, the control means may be arranged to
release the restraining means in the event of a power failure or a fire
allowing the closure to be opened.
-
The invented control system may be applied to any type of closure but is
particularly intended to control movement of doors, especially automotive
doors.
-
For application to automotive doors mounted for pivotal movement
between open and closed positions, the monitoring means is preferably
arranged to detect torque loads applied to the door by pushing or pulling
and to generate a signal to the control means when the pre-determined
torque has been applied for a pre-set time, for example 2 seconds. In this
way, accidental release of the restraining mechanism by a gust of wind
when the door is open or by a person leaning on the door when closed is
prevented.
-
Longer or shorter time delays may be employed as appropriate for a
particular application and it may be desirable for certain applications to
have no delay so that the restraining mechanism is released when the pre-determined
torque has been applied.
-
According to a second aspect of the invention there is provided a control
system for a closure such as a vehicle door, the system comprising
restraining means for releasably holding the closure in an open position,
sensor means for monitoring at least one parameter representative of a
condition of the closure, and logic control means responsive to the sensor
means for controlling the restraining means according to the detected
condition of the closure.
-
The sensor means may be arranged to monitor movement of the closure
and the logic control means is responsive to the sensor means to apply the
restraining means under pre-set conditions. For example the restraining
means may be applied when the closure is stationary or slowing down or
speeding up.
-
Thus, the restraining means may be actuated to hold the closure when it is
not moving or if it is moving slower or faster than pre-set lower and
upper limits.
-
Alternatively or additionally, the sensor means may be arranged to
monitor an operating force applied to the closure such as when pushing or
pulling a pivotally mounted closure, and the logic control means is
responsive to the sensor means to release the restraining means at a pre-determined
operating force. The operating force may be set to prevent
accidental or inadvertent release of the restraining means.
-
In a preferred arrangement, the sensor means is arranged to monitor both
movement of the closure and the operating force applied to the closure
with the logic control means being responsive to signals from the sensor
means representative of the movement and operating force to apply and
release the restraining means respectively for holding the closure in any
selected one of a range of open positions.
-
By this arrangement, the open position of the closure may be finely
adjusted between closed and fully open positions enabling the closure to
be held at a series of closely spaced apart positions. For example,
angular adjustment of a few degrees, preferably about 5° and more
preferably of the order of 1-2°, may be obtained between the hold open
positions of the closure.
-
By such incremental adjustment of the position of the closure, the opening
movement can be adapted to the available space so as to avoid damage to
the closure. The incremental adjustment may be reduced so as to provide
substantially infinite adjustment of the hold open position of the closure.
-
According to a third aspect of the invention, there is provided a control
system for a vehicle door comprising means for releasably holding the
door open, means for monitoring loads applied to the door and generating
a signal when a pre-determined load is applied, and means responsive to
the signal for releasing the holding means to allow movement of the door
to a new position.
-
According to a fourth aspect of the invention there is provided a control
system for a vehicle door comprising means for monitoring movement of
the door and generating a signal representative thereof, and means
responsive to the signal for releasably holding the door when stationary.
-
The invention will now be described in more detail, by way of example
only, with reference to the accompanying drawings in which:-
- Figure 1 shows schematically a door control system embodying the
invention;
- Figures 2A and 2B are sectional views, at right angles to each
other, showing application of the door control system to a
restraining mechanism for a vehicle door; and
- Figure 3 shows a function logic block diagram for controlling
operation of a restraining mechanism for a vehicle door.
-
-
Referring first to Figure 1 of the drawings, there is shown a door 1
mounted for pivotal movement relative to a frame 2 about a vertical axis
at one side by a pair of hinges 3,4 between open and closed positions.
The door 1 may be of any type but in a preferred application of the
invention is a vehicle door.
-
The door 1 is pivotal towards and away from the closed position and is
releasably held in any desired open position by a restraining mechanism
indicated schematically by reference numeral 5.
-
The restraining mechanism 5 is operable under the control of a logic
controller 6 described in more detail later to apply a restraining torque to
hold the door 1 in any selected open position and to release the
restraining torque to allow pivotal movement of the door 1 towards or
away from the closed position.
-
Any system of applying the restraining torque may be employed. For
example, a brake device (not shown) mounted within the door cavity co-operable
with a link (not shown) pivotally connected at one end to the
door frame 2 and arranged to move through the brake device as the
door 1 moves towards and away from the closed position.
-
In a known manner, the link includes an end stop co-operable with the
brake device to limit opening movement of the door 1. In the case of a
vehicle door, opening movement would typically be limited to a maximum
of 60° but the range of opening movement may be varied according to the
application.
-
The brake device is operated under the control of the logic controller 6 to
apply a braking force to the link to hold the door 1 stationary at the
selected open position and to release the braking force to allow the door 1
to move from the selected open position.
-
Any brake device could be added for this purpose. For example, friction
pads to apply a frictional braking force to the link. Alternatively, co-operating
plungers and indents may be provided to hold the door 1 at the
selected open position. It will be understood, however, that other
methods could be used including but not limited to hydraulics,
pneumatics, electro magnets and ferro-fluidics.
-
Furthermore, whilst the restraining mechanism has been described in the
form of a brake device and co-operating link, it will be appreciated that
the restraining mechanism could be incorporated in one or both hinges 3,4
or any other arrangement capable of stopping and preventing movement of
the door 1.
-
The logic controller 6 controls the restraining mechanism 5 to apply and
release the braking force to the door 1 in response to a device 7 for
monitoring the operating torque applied to the door 1 and a device 8 for
monitoring movement of the door 1.
-
The device 7 senses the operating torque being applied to the door 1, for
example by a pushing or pulling action, and sends a signal to the logic
controller 6 when a pre-determined torque is reached. The logic
controller 6 in turn is responsive to the signal to cause the restraining
mechanism 5 to release the braking force applied to the door 1 allowing
the door 1 to move from the position in which it was being held by the
restraining mechanism 5.
-
The applied torque may be detected by means of electronic sensors such
as strain gauges or load cells. Alternatively, the applied torque may be
detected by movement of an element against a pre-loaded spring. It will
be understood, however, that the actual method employed is not essential
and that any system of monitoring the applied torque may be employed.
-
The pre-determined torque to release the restraining mechanism 5 may be
set at any desired level appropriate to the given application and the
device 7 may be arranged to generate the signal only when the pre-determined
torque has been applied for a pre-determined time. In this
way, inadvertent or accidental release of the restraining mechanism 5 by
an instantaneous torque e.g. from a gust of wind, does not release the
door 1.
-
The device 8 senses movement of the door 1 and sends a signal to the
logic controller 6 according to whether the door 1 is moving or
stationary. The logic controller 6 in turn is responsive to the signal to
cause the restraining mechanism 5 to apply the braking force to the
door 1 under pre-set conditions.
-
For example, the restraining mechanism may be applied when the door 1
is stationary or slowing down or speeding up. Thus, the restraining
mechanism may be applied when the door is moving slower than a pre-determined
lower speed or faster than a pre-determined upper speed. In
this way, the restraining mechanism is applied if the door slows down to
secure the door at the desired position of adjustment, and if the door
speeds up to secure the door and prevent uncontrolled movement of the
door such as by a gust of wind.
-
The movement may be detected by the use of a proximity sensor which
detects the presence or absence of teeth on the edge of a wheel so that, as
the wheel rotates, the proximity sensor will detect an intermittent signal
and, if the wheel is stationary, the proximity sensor will detect a steady
signal. Thus, by urging the wheel to rotate as the door 1 moves, the
motion of the door 1 is detected. It will be understood, however, that the
actual method employed is not essential and that any system of monitoring
movement may be employed. For example, systems could be configured
with the use of optical or magnetic sensors such as used in automotive
anti-lock braking systems. Magnetic zones in a moving element could be
used to generate small electrical pulses which in turn could be detected to
indicate movement of the door 1.
-
As thus far described, the restraining mechanism 5 is operable to prevent
movement of the door 1 until a pre-determined operating force is applied
and detected by the device 7. The logic controller 6 responds to a signal
from the device 7 to cause the restraining mechanism 5 to release the
braking force holding the door 1 and allowing the door 1 to be moved
from the position in which it was being held to a new position. The
movement of the door 1 is detected by the device 8 and the logic
controller 6 responds to a signal from the device 8 when it no longer
detects movement or the movement is slower or faster than a pre-determined
speeds to cause the restraining mechanism 5 to apply the
braking force to hold the door 1 at the new position.
-
As will now be appreciated, the invented door control system enables the
position of the door 1 to be adjusted between the closed and open
positions with the door 1 being held in any desired open position. This
has particular benefits for application of the system to vehicle doors
where the extent to which the door 1 can be opened may vary widely
according to the position in which the vehicle is parked. Thus, the door
can be opened as far as permitted and held in that position to allow access
to and egress from the vehicle until it is desired to close the door without
risk of damage by contact with an adjacent vehicle, wall, pillar or other
structure obstructing full opening movement of the door.
-
Although the invention has been described thus far in its simplest form, it
will be understood that the control system can be adapted to the particular
needs of any given application by the addition of other features of which
some are now described by way of example only.
-
For some applications of the system, especially for vehicle doors, it is
desirable to control movement of the door when the restraining
mechanism 5 is released. This may be achieved by employing a device to
apply a constant braking torque to the door 1 which prevents the door 1
moving freely in an uncontrolled manner. Any suitable device may be
employed for this purpose. For example, where the restraining
mechanism includes a link arm as described previously, a constant
braking torque may be provided by a friction pad bearing on the link arm.
-
The door may be held in the closed position by the restraining mechanism
alone, for example where the control system is applied to internal doors
in buildings. For some applications of the system, however, especially
for vehicle doors, it is necessary to prevent the door opening accidentally
or inadvertently if someone leans against the door. This may be achieved
by means of a latch mechanism operable automatically to secure the door
when it is moved to the closed position and which is manually releasable
by means of an actuator such as a handle. In this arrangement, the
restraining mechanism may be released when the door 1 is closed as it is
not required to hold the door closed.
-
For example, a sensor such as a "door closed" switch may be provided to
detect when the door is closed and give a signal to the logic controller to
release the restraining mechanism. Alternatively, the restraining
mechanism may be applied when the door is closed and released in
response to operation of the actuator. Such operation may be effected by
incorporating a door operating sensor such as a switch responsive to
operation of the actuator in the control loop for the restraining
mechanism. The restraining mechanism may be re-applied when the
actuator is released. Alternatively, the restraining mechanism may be re-applied
in response to the signal from the movement sensor.
-
In another arrangement, the restraining mechanism may be released by
means of a contact sensor such as a touch sensitive operating pad
arranged to sense contact with the door. The restraining mechanism may
be re-applied when the contact sensor is released or in response to the
signal from the movement sensor. Any suitable contact sensor may be
employed with operation by earth leakage, pressure, direct switching or
any other appropriate method.
-
Referring now to Figures 2A and 2B, there is shown an example of the
application of the invented control system to a vehicle door arrester 10
for controlling movement of a vehicle door (not shown) relative to a door
frame (not shown).
-
The arrester 10 comprises an elongate link arm 11 slidable through a
housing 12, and a restraining mechanism 13 located in the housing 12 to
hold releasably the link arm 11 and secure the door in selected positions.
-
The link arm 11 is the form of a flat bar of rectangular section pivotally
connectable at one end to the door frame and having serrations 14 on each
side edge face 15. The housing 12 is mountable on the door and the link
arm 11 extends through the housing 12 and through a block 16 located in
a cavity 17 within the housing 12.
-
Mounted in the block 16 is a pressure pad 18 biased by a spring 19 to
engage an upper surface 20 of the link arm 11 to apply a constant
frictional braking force to sliding movement of the link arm 11 through
the housing 12.
-
Also mounted in the block 16 is a roller 21 supported for rotation by a
spindle 22. The roller 21 contacts a lower surface 23 of the link arm 11
and is rotated by sliding movement of the link arm 11 through the
housing 12. The surface of the roller 21 has circumferentially spaced
formations such as teeth.
-
A proximity sensor 24 is arranged to receive a steady signal when the
roller 21 is stationary and an intermittent signal when the roller 21 is
rotating. The proximity sensor 24 sends a signal to a logic controller (not
shown) according to whether the roller 21 is stationary or rotating to
indicate if the link arm 11 is moving or not.
-
The restraining mechanism 13 is provided by a pair of blades 25,26
arranged to co-operate with the serrations 14 on the side edge faces 15 of
the link arm 11. One of the blades 25 is fixed. The other blade 26 is
movable towards and away from the adjacent side edge face 15 under the
control of a cam 27 operable by an actuator 28 such as a pneumatic
cylinder 29 in response to a signal from the logic controller.
-
The restraining mechanism 13 is shown in the locked state in Figure 2B in
which the cam 27 is advanced to urge the movable blade 26 towards the
link arm 11 so that both blades 25,26 engage respective serrations 14 on
the side edge faces 15 to secure the link arm 11.
-
In this condition, the block 16 is biased to a centre position within the
cavity 17 by a pair of springs 30,31 as shown in Figure 2A. If a force is
applied to the door in the direction of sliding movement of the link
arm 11 to open or close the door as indicated by the arrows in Figure 2A
with the link arm 11 held by the restraining mechanism 13, the block 16
will move in the direction of the applied force against the biasing of the
spring resisting such movement. When the applied force is sufficient to
displace the block 16 a pre-determined amount from the centre position,
such movement is detected by a sensor 32 which sends a signal to the
logic controller to retract the cam 27 releasing the restraining
mechanism 13 and allowing the link arm 11 to slide through the
housing 12 to adjust the position of the door.
-
The roller 21 rotates in response to such movement and, when the link
arm 11 stops or the speed of movement falls below a lower limit or
exceeds an upper limit, the sensor 24 sends a signal to the logic controller
to re-apply the restraining mechanism 13 to secure the link arm 11.
-
As will be appreciated, the co-operation of the blades 25,26 with the
serrations 14 enables fine adjustment to be made to the position in which
the link arm 11 is secured. In this way, small changes in the angular
position of the door can be made providing substantially infinite
adjustment to the open position of the door. As a result, the extent of
opening movement of the door can be adjusted according to the available
space for a given condition thereby reducing the risk of damage to the
door from accidental contact with an adjacent structure.
-
The restraining mechanism 13 may be applied to hold the door in closed
or open positions or in open positions only with a separate latch
mechanism for securing the door closed. Where the door is secured
closed by a latch mechanism, a sensor may be provided to detect when the
door is closed and give a signal to the logic controller to release the
restraining means, for example the sensor may be a "door closed" switch.
-
The above is one example of the possible application of the invented door
control system and it will be understood the invention is not limited to the
details thereof.
-
Referring now to Figure 3, there is shown a function logic block diagram
for controlling operation of the invented door control system and control
movement of a vehicle door.
LOGIC INPUTS ARE:-
-
Move sensor - This is a pulsed signal, which indicates that the door is
moving. This signal might be taken from a sensor detecting the rotation
of a toothed roller as described previously.
-
Door closed - This is a steady signal, which is present when the door is
closed. This might be derived from a switch, in a similar style to a
courtesy light switch.
-
Load sensor - This is a temporary signal, which indicates that there is an
operating load on the door. This may be derived from a touch pad on the
door's surface or from a load detection device in the door arrester
mechanism as described previously.
LOGIC OUTPUTS ARE:-
-
Hold door - This is a 'one-shot' (0.5s) signal, which would operate an
actuator. The actuator would engage a door holding mechanism as
described previously.
-
Loose door - This is a 'one-shot' (0.5s) signal, which would operate the
actuator in the opposite direction. The actuator would disengage the door
holding mechanism as described previously.
THE FUNCTION OF THE LOGIC IS AS FOLLOWS:-
-
The roller stops moving when the door is stationary and this condition is
signified when a signal is received from the move sensor for longer than a
pre-determined duration, for example 0.3s, in either an "on" or "off"
state.
-
If either an 'on' signal or an "off" signal is received from the move
sensor for longer than 0.3s indicating the door is stationary and, if the
door has not been closed for 0.6s, then the hold door signal is generated
to engage the door holding mechanism and the door will be held in it's
position.
-
If a signal is received from the door operating load sensor or if the door
is fully closed then the loose door signal is generated to release the door
holding mechanism and the door will be released.
-
It will be understood that the logic controller may be programmed to
provide any desired operating functions to suit the requirement for a
given application and all combinations and alternatives are within the
scope of the invention.
-
The logic controller may also be employed to provide fail-safe operating
modes. For example, to allow the restraining mechanism to be over-ridden
in the event of a power failure or an emergency. Thus, by linking
to a fire detection system, the logic controller could allow the door to
open in the event of a fire. Other applications and uses of the invented
control system will be apparent to these skilled in the art.
