TECHNICAL FIELD
[0001] This disclosure relates to a window having an electrically pivotable sash and the
electrically operated actuator used for operating such a sash. Particularly, the disclosure
relates to anti-pinch sensing and control of the movement of the sash.
BACKGROUND
[0002] EP 2754820 discloses a pivotable window with an actuator on each side. Each actuator has a safety
strip on the actuator housing to detect an object entrapped between the actuator housing
and the window frame.
[0003] EP 1441100 discloses a pivotable window without pinch detection. Instead, the closing movement
is performed stepwise to increase the attention of the person nearby and to limit
the risk of pinching.
[0004] However, due to various reasons which are explained below, it has shown to be difficult
to provide a reliable pinch detection, which also is cost effective. Further, it is
an object to provide an actuator, which is easy to retrofit to a window that is already
installed in a building.
[0005] Different window sizes may use the same actuator drive, yet require different closing
forces. The final closing movement of a window sash creates a spike in the closing
force needed to compress the gasket between the frame and sash.
Wind or draft can also change the closing force needed. Some pivotable windows such
as roof windows may be installed in differently sloped roofs and consequently the
force requirements may differ. Further, snow may change the weight of the window sash
temporarily and hence the closing force needed. Likewise, the window may be retrofitted
with a blind or a shutter which also changes the weight of the sash. As a window ages,
the resistance (friction) and closing forces also change.
SUMMARY
[0006] It is an object of the invention to solve or at least reduce the problems indicated
above, and to provide a solution which compensates for sample tolerances, installation
differences, and wear and tear of a roof window.
[0007] This object is achieved according to a first aspect by an electrically operated actuator
for operating a window, the window comprising a frame, a sash being pivotally suspended
from the frame by a horizontal pivot axis and, when pivoted, positioned in one of
an open position zone, a near closed position zone, and a visually closed position
zone, a compressible seal or gasket being provided between the frame and the sash
such that it bridges at least a part of the visually closed position zone, the actuator
being adapted to perform a first closing operation while monitoring an indicator of
a closing force applied onto the sash by the actuator, the actuator further being
adapted to initiate a first reversing operation upon the indicator of closing force
exceeding a threshold during the first closing operation, and the actuator being configured
to initiate a subsequent, second closing operation after the first reversing operation,
monitoring of the indicator of closing force being disengaged when the sash reaches
the visually closed position zone.
[0008] By closing the window with the force limited to a relatively low first threshold
a pinching event or entrapment event can be detected without large force being applied
to the trapped or pinched object. The reversing action allows the trapped or pinched
object to be removed, before the second closing action takes place. The second closing
action can be carried out with a higher threshold allowing a larger force to be applied
to the window. This larger force may be necessary due to excessive friction or wind
conditions. Thus, proper closing of the window is ensured whilst the risk of injury
to e.g. fingers or other body parts of a person is reduced since the person will have
a chance to remove their hand, fingers or other body part during the reversing operation.
Thus, there is provided an enhanced entrapment detection, which does not terminate
the closing operation due to false pinching signals caused, e.g., by strong winds.
Further, it is ensured that the window closes while still allowing trapped objects
to escape.
[0009] In a first possible implementation form of the first aspect, the actuator is configured
to monitor the indicator of closing force during the second closing operation, adapted
to initiate a second reversing operation upon the indicator of closing force exceeding
a threshold during the second closing operation, and further configured to initiate
a subsequent, third closing operation after the second reversing operation.
[0010] In a second possible implementation form of the first aspect, the actuator is adapted
to perform at least one further reversing operation upon the indicator of closing
force exceeding a threshold, and at least one further subsequent closing operation.
[0011] In a third possible implementation form of the first aspect, the subsequent closing
operation is executed without monitoring the indicator of closing force.
[0012] In a fourth possible implementation form of the first aspect, the actuator is configured
to apply the maximum closing force if needed during the subsequent closing operation.
[0013] In a fifth possible implementation form of the first aspect, the actuator is driven
by an electric drive motor and the closing operation is executed at at least one of
a plurality of electric drive motor speeds.
[0014] In a sixth possible implementation form of the first aspect, the electric drive motor
is operated at a normal closing speed when the sash is positioned in the open position
zone.
[0015] In a seventh possible implementation form of the first aspect, the electric drive
motor is operated at a decreased speed when the sash is positioned in the near closed
position zone.
[0016] In an eight possible implementation form of the first aspect, the electric drive
motor is operated at an increased speed when the reversing operation is executed.
[0017] This object is also achieved according to a second aspect by a method of closing
a window by means of an actuator according to the above, the window comprising a frame,
a sash being pivotally suspended from the frame by a horizontal pivot axis and, when
pivoted, positioned in one of an open position zone, a near closed position zone,
and a visually closed position zone, the method comprising performing a first closing
operation while monitoring an indicator of a closing force applied onto the sash by
the actuator, initiating a first reversing operation upon the indicator of closing
force exceeding a threshold during the first closing operation, initiating a subsequent,
second closing operation after the first reversing operation, disengaging the monitoring
of the indicator of closing force when the sash reaches the visually closed zone.
[0018] In a first possible implementation form of the second aspect, the method comprises
performing a second closing operation while monitoring the indicator of closing force
applied onto the sash by the actuator, initiating a second reversing operation upon
the indicator of closing force exceeding a threshold during the second closing operation,
and initiating a subsequent, third closing operation after the second reversing operation.
[0019] In a second possible implementation form of the second aspect, the method comprises
at least one further reversing operation upon the indicator of closing force exceeding
a threshold, and at least one further subsequent closing operation.
[0020] In a third possible implementation form of the second aspect, the subsequent closing
operation is executed without monitoring the indicator of closing force.
[0021] The foregoing and other objects are achieved by the features of the independent claims.
Further implementation forms are apparent from the dependent claims, the detailed
description, and the figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] In the following detailed portion of the present disclosure, the invention will be
explained in more detail with reference to the example embodiments shown in the drawings,
in which:
Fig. 1 illustrates an example embodiment of a pivoting roof window with a chain actuator,
Fig. 2 illustrates an example of a pivoting roof window with an exterior sun screening
installed,
Fig. 3 is a diagrammatic illustration of a window actuator with a control unit,
Fig. 4 is an elevated view of the window actuator of Fig. 3,
Fig. 5 is an elevated cutaway view of a portion of the window actuator of Fig. 3,
Fig. 6 shows an example of measured motor current, a low-pass filtered motor current,
a filtered current derivative, and a filtered current derivative threshold of the
motor of the window actuator,
Fig. 7 is a graph illustrating a closing procedure for a window with a window actuator,
Fig. 8 is a flowchart illustrating the closing procedure of Fig. 7,
Fig. 9 is a graph illustrating another closing procedure for a window with a window
actuator,
Fig. 10 is a flowchart illustrating the closing procedure of Fig. 9,
Fig 11. illustrates the open position zone, the near closed position zone, the visually
closed position zone, and the fully closed position of a pivoting roof window, and
Fig. 12a, 12b, and 12c illustrate an example embodiment of a section of a pivoting
roof window in a near closed position, a visually closed position, and a fully closed
position, respectively.
DETAILED DESCRIPTION
[0023] Fig. 1 illustrates a roof window 1 with top hung rectangular sash 3 with a window
pane 4 therein and a matching rectangular frame 2, i.e. the sash 3 is pivotally connected
to the frame 2 along its top member by a hinge for pivotal movement of the sash 3
between a closed position D and any number of open positions. Fig. 2 illustrates a
roof window 1 with a pivot hung sash 3 and a matching rectangular frame 2. The roof
window 1 of Fig. 2 is provided with an exterior sun screening 6.
[0024] The roof window of Fig. 1 and Fig. 2 is provided with a compressible gasket (shown
in Fig. 12) between the rectangular sash 3 and the rectangular frame 2. The compressible
gasket is tightly compressed or deformed between the rectangular sash 2 and the rectangular
gasket 3 when the roof window 1 is fully closed. The roof window is further provided
with an actuator for moving the window i.e. moving the sash 3 between an open position
and a fully closed position D (see Fig. 11 and Fig. 12c). The actuator can be any
suitable type of actuator, e.g. a push-pull (thrust) chain actuator such as that shown
in Fig. 1. The actuator itself can be installed in or on the frame 2, or in or on
the sash 3. The actuator need not be installed at the bottom member of a window as
shown in Fig. 1, but could be installed at the opposite side, i.e. the top member
of the window.
[0025] The sash 3 is pivotally suspended from the frame 2 by a horizontal pivot axis and,
when pivoted, positioned in one of an open position zone A, a near closed position
zone B, and a visually closed position zone C, see Fig. 11 and Fig. 12a-c. The compressible
seal or gasket 5, provided between frame and sash, bridges at least a part of the
visually closed position zone C. When the sash 3 is locked, it is in the fully closed
position D. In the visually closed position C, the gasket and lock are about to engage
with a corresponding window component.
[0026] In one embodiment, the distance between the frame 2 and a section of the sash 3 is
at least 25 mm when the sash is in the open position zone A. The distance d is shown
schematically in Fig. 12a. The visually closed zone C extends from the frame 2 and
at least up to an outer limit of the seal or gasket 5, in one embodiment past the
outer limit of the seal or gasket 5, such that the seal or gasket 5 bridges at least
a part of the visually closed zone C. In the visually closed zone, the window appears
to be closed and it is nearly impossible to become trapped between the sash 3 and
the frame 2. In the nearly closed position zone, the seal or gasket 5 is always uncompressed.
[0027] For illustration purposes, a roof window has been shown in Figs. 1 and 2, but it
is understood that the actuator can be used also for other types of windows, particularly
for any other type of top hung or pivot hung window. The actuator is particularly
suitable for retrofitting onto an existing window, e.g. a manually operated window,
since it does not require additional components such as special locks or external
sensors.
[0028] Figs. 3 to 5 shows an embodiment of an actuator 10 in the form of a push-pull chain
actuator with a push-pull chain 11. However, it is understood that the actuator can
be of another type, in particular any type of linear actuator such as e.g. a spindle
actuator. The actuator 10 comprises a housing 15 that holds an electric drive motor
12, a chain magazine, a push-pull chain 11, and a position sensor 14. The electric
drive motor 12 may be linear or a rotating electric motor connected to means that
convert the rotational movement of the electric drive motor 12 to linear movement.
The position sensor can, e.g., be a rotary pulse generator on the electric motor 12.
[0029] The actuator 10 is provided with an electronic control unit 50. The electronic control
unit 50 can be external to the actuator 10 or it can be located in the housing 15.
In one example, the electronic control unit 50 is embedded in a secure separate processor
to provide fail-safe operation. The electronic control unit 50 is connected to a source
of electric power and configured to control the operation of the actuator 10, i.e.
to control the operation of the electric drive motor 12. Typically, there will be
a single electric drive motor 12. However, in an embodiment there can be two drive
motors 12 in tandem, as shown in Fig. 5.
[0030] The closing force applied onto the sash by the actuator 10 is preferably the same
regardless of the speed of the electric drive motor 12. In one embodiment, the force
is measured by monitoring an indicator of a closing force. Such an indicator may,
e.g., be the electric current directly consumed by the electric drive motor 12. However,
in an embodiment, the actual current is measured and the derivative of the current
calculated. The derivative of current is, by other words, the rate of change over
time of the consumed current. By calculating the derivate, atypical deviations such
can be disregarded, and the indication of a pinching event enhanced.
[0031] When monitoring the derivative, the magnitude of the rate of change in current is
monitored instead of the actual motor current. If something or someone is trapped
between frame and sash, the motor current will increase rapidly and significantly.
The derivative indicates how fast the motor current increases, and if the derivative
is high enough, a threshold will be reached and entrapment detected. See, e.g., the
slope of the derivative curve D
F in Fig. 6 between times t
1 and t
2, as well as derivative threshold D
Th.
[0032] In one embodiment, the monitoring of the indicator of closing force comprises calculating
the derivative, i.e. rate of change, of filtered electric current IF consumed by the
electric drive motor 12 over a change in time, (I
2-I
1)/(t2-t1), and comparing the calculation to a predetermined threshold value D
Th.
[0033] In a further embodiment, the monitoring of the indicator of closing force instead
comprises calculating the derivative/ rate of change of filtered electric current
consumed by the electric drive motor 12 over a constant time window, while adjusting
the threshold value D
Th e.g. in relation to the speed of the electric drive motor 12. A lower speed requires
a lower threshold due to a slower rate of change, and vice versa.
[0034] The measured electric current I
M is, in one embodiment, filtered by means of a signal processing unit. The filtering
is executed prior to calculating the derivative/rate of change, in which calculation
the filtered current I
F is used. The filter parameter of the signal processing unit may be selected from
a plurality of predetermined filter parameters; each filter parameter being related
to, e.g., the speed of the electric motor 12 and/or the position of the sash 3.
[0035] By filtering the current and monitoring the derivative/rate of change, false entrapment
detection is avoided to a large extent since a slow increase in rate of change, i.e.
force, e.g. due to wind, is disregarded.
[0036] Fig. 6 shows a graph that illustrates the measured electric current I
M in A to the electric drive motor 12 over time as well as the measured low-pass filtered
current I
F in A to the electric drive motor 12 over time. The increase of the current I
M, I
F towards the end of the time span and thus of the force applied by the actuator 10
to the sash can be an indication of a pinching event. Figure 6 further illustrates
the derivative D
F, i.e. rate of change, of the filtered current I
F as well as a threshold D
Th for said derivative D
F. A significant increase in current and derivative is shown between times t
1 and t
2, which leads to the derivative threshold D
Th being exceeded at t
2.
[0037] The electronic control unit 50 receives instructions, e.g. from a remote-control
unit (not shown), a sensor system such as a fire alarm (not shown), a timer, or a
rain sensor, or from a control panel (not shown), to close an open window 1 completely
or to move the window 1 to a desired intermediate position. The instructions can also
come from a control system that controls the climate of a building by adjusting the
opening of windows in such building.
[0038] If the window is open, as shown in Figs. 1 and 2, the electronic control unit 50
may receive an instruction to close the window 1. The electronic control unit 50 is
configured to initiate a first closing operation upon receipt of such an instruction.
Each closing operation is executed at, at least one of, a plurality of electric drive
motor speeds.
[0039] An example of a closing procedure is illustrated in Fig. 7. At the start of the closing
procedure the electronic control unit 50 has received an instruction to close the
window. Thereupon, the electronic control unit 50 initiates a first closing operation
101. During the first closing operation 101 the electronic control unit 50 monitors
the indicator of closing force applied to the sash by the actuator 10, e.g. by monitoring
the derivative/rate of change of the current delivered to the electric drive motor
12. The electronic control unit 50 is configured to monitor that the force applied
to the window does not exceed a first threshold. The first threshold preferably relates
to a force which is low enough to avoid injury if a body part, such as the hand or
fingers or person is trapped in the window opening, i.e. the opening between the sash
3 and the frame 2.
[0040] The electronic control unit 50 is configured to continue the first closing operation
101 until the window 1 is fully closed if the instructions received by the electronic
control unit 50 are to close the window 1 completely. If the instructions are to close
the window to a desired position n, for example a ventilating position in which the
window is slightly open, the procedure lasts until the desired position is reached.
In the example in Fig. 7 the instruction received by the electronic control unit 50
is to close the window 1 completely.
[0041] At time T1, the derivative/rate of change of the current delivered to the electric
drive motor 12 exceeds the first threshold (indicated as D
Th in Fig. 6) and the electronic control unit 50 is configured to terminate the first
closing action 101 and to initiate a first reversing action 102. The first reversing
action 102 is preferably a relatively small movement, i.e. relatively small compared
to a full movement of the window 1 between its fully open position and fully closed
position. The first reversing action should 102 be large enough for a person to move
a trapped body part away from the window 1.
[0042] The electronic control unit 50 is configured to hold the window still for a first
short period of time 103 after the first reversing action has been completed, in order
to give a person, that has a body part trapped, time to move this body part away from
the window 1. The short period of time 103 is a brief time. The short period of time
could be a momentary pause allowing a trapped body part to be removed.
[0043] The electronic control unit 50 is configured to initiate a second closing operation
104 at the end of the first short period of time 103. The electronic control unit
50 is in an embodiment configured to monitor the indicator of closing force applied
by the actuator 10 to the window 1, i.e. derivative/rate of change of the current
delivered to the electric drive motor 12, during the second closing operation 104,
and to terminate the second closing operation 104 if the derivative/rate of change
exceeds a second threshold. The second threshold can be identical to the first threshold,
but also be higher or lower than the first threshold. In an embodiment, the electronic
control unit 50 is configured to allow the actuator to apply its maximum force during
the second closing operation 104. Either, or both, of the first threshold and the
second threshold may be set to indicate a force which is lower than the maximum force
of the actuator. The maximum force may, e.g., be set to 400 N.
[0044] Each threshold is selected from, or automatically matched to one of, a plurality
of predetermined thresholds. In one embodiment, the threshold is selected/matched
in response to the speed of the electric drive motor 12 and/or the position of the
sash 3. Each specific speed of the electric drive motor 12 belongs to one of a plurality
of predetermined speed ranges. In one embodiment, the speed ranges comprise a low-speed
range and a high-speed range. The speed ranges may comprise additional ranges such
as a normal-speed range for speeds between the low-speed range and the high-speed
range, the normal-speed range being the speed at which the electric drive motor 12
operates during the main part of the closing operation. The electric drive motor 12
speed may be selected in response to the position of the sash 3. The electric drive
motor 12 may be operated at a normal closing speed, in the normal-speed range, when
the sash 3 is positioned in the open position zone A. Further, the electric drive
motor 12 may be operated at a decreased speed, in the low-speed range, when the sash
3 is positioned in the near closed position zone B, and the electric drive motor 12
may be operated at an increased speed, in the high-speed range, when the reversing
operation is executed. The very highest threshold possible may be selected when the
electric drive motor speed is in the high-speed range and/or the sash is in the open
position zone A. Correspondingly, the lowermost threshold may be selected when the
electric drive motor speed is in the low-speed range and/or the sash 3 is in the near
closed position zone B. The electric drive motor speed may be decreased in order to
reduce the noise made by the window 1 when beginning to lock the sash to the frame
in the visually closed zone C.
[0045] Fig. 8 is a flowchart illustrating the operation of the actuator 10. After start,
the electronic control unit 50 receives instructions to move the window 1 to a target
position, e.g. the fully closed position of the window 1. Thereupon, the electronic
control unit 50 initiates the first closing operation 101 while monitoring the closing
force applied to the window 1. The electronic control unit 50 determines whether a
first threshold is exceeded during the first closing operation 101. If the first threshold
is not exceeded the electronic control unit 50 verifies whether the target position
has been reached during the first closing operation 101. If the target position has
not been reached the electronic control unit 50 continues with the first closing operation
101. When the electronic control unit 50 detects that the target position has been
reached, the electronic control unit terminates the first closing procedure 101. If
the target position was the fully closed position, the first closing procedure 101
ends with the window 1 in its fully closed position.
[0046] If the electronic control unit 50 detects that the closing force exceeds the first
threshold during the first closing operation 101, the electronic control unit 50 initiates
a first reversing operation 102 and thereafter maintains the position of the window
1 for a first short period of time 103, e.g. less than a couple of seconds.
[0047] At the end of the first short period of time 103, the electronic control unit 50
initiates the second closing operation 104. The electronic control unit 50 may continue
to monitor the indicator of closing force, or it may disengage, i.e. not monitor,
the closing force during the second closing operation 104 and allowing the actuator
10 to apply its maximum closing force during the second closing operation 104. The
electronic control unit 50 is configured to verify whether the target position has
been reached during the second closing operation 104. If the target position has not
been reached the second closing operation continues. When the target position has
been reached, the process ends and electronic control unit 50 is ready to receive
new instructions. In one embodiment, monitoring of the indicator of closing force
is disengaged when the sash reaches the visually closed zone C.
[0048] Even if monitoring is disengaged, there is a restriction on the allowed maximum force
in order to limit the force exerted on the electric drive motor 12, i.e. overload
protection. The maximum current limit may be set at 100 % when the sash is in the
open position zone A, and reduced to 35 % when the sash reaches the visually closed
position zone C. This will reduce the mechanical stress on the motor. E.g., the maximum
closing force may be at least 36 kg and at the most 45 kg.
[0049] In an embodiment, that can be combined with any of the other embodiments, the electronic
control unit 50 is configured to allow the actuator 10 to apply its maximum force
during the very last part of the closing movement towards the fully closed position
of the window 1. The very last part of the closing movement, the visually closed position
zone, is preferably selected so small that it is difficult, if not impossible, for
a person to get his fingers or other body part trapped between the frame 2 and the
sash 3, and thus on one hand the risk of a pinching event is small and on the other
hand a large force is typically needed for compressing the compressible gasket 5 in
this part of the movement. The portion of the closing movement in which the compressible
gasket needs to be compressed typically requires a much larger force to be carried
out.
[0050] In an embodiment, illustrated with reference to Figs. 9 and 10, the electronic control
unit 50 is configured to perform at least two reversing actions, when a respective
first and second threshold is exceeded, before at least a third closing operation
is carried out with a higher third threshold or without any limit on the force applied
to the window. Each threshold is selected from a plurality of predetermined thresholds.
Any number of reversing actions and subsequent closing actions is possible, and not
limited to two or three. Each such closing action may comprise either monitoring against
a specific threshold, or closing without monitoring. Also, any closing operation,
deemed to be the last and final closing operation, may be closed without any limit
on the force applied to the window.
[0051] This closing process is identical to the process described with reference to Figs.
7 and 8 up to the end of the short period of time 103. During the second closing operation
104 the electronic control unit 50 is configured to verify that the closing force
does not exceed a second threshold. The second threshold can be identical to the first
threshold or can be lower than the first threshold or can be higher than the first
threshold. In an example, the first threshold can be set at 5 kg (12 %), with the
second threshold being set at 10 kg (25 %). A further example is a first threshold
set at 15 kg (37 %) The electronic control unit 50 is configured to terminate the
second closing operation 104 and to initiate a second reversing operation 105 upon
detecting that the second threshold has been exceeded. The second reversing operation
105 is preferably a small operation with a small stroke, similar to the first reversing
operation 102 and small relative to the maximum movement of the window 1 between its
fully closed and fully open position.
[0052] The electronic control unit 50 is configured to hold the window 1 still for a second
short period of time 106 after the second reversing action 105 has been completed,
in order to give the person that has a body part trapped one more opportunity to move
this body part away from the window 1. The electronic control unit 50 is configured
to initiate a third closing operation 107 at the end of the second short period of
time 106. The electronic control unit 50 is in an embodiment configured to monitor
the force applied by the actuator to the window during the third closing operation
107 and to terminate the third closing operation 107 if the force exceeds a third
threshold. Either, or all, of the first, second, and third thresholds may be set to
indicate a force which is lower than the maximum force of the actuator. The third
threshold is preferably higher than the first and second threshold, e.g. 400 N. In
an embodiment, the electronic control unit 50 is configured to allow the actuator
10 to apply its maximum force during the third closing operation 107.
[0053] The process of closing the window in accordance with the embodiment of Figs. 9 and
10, is identical to the process described in the flowchart in Fig. 8 up to, and including,
maintaining the position of the window for the first short period of time 103. At
the end of the first short period of time 103 the electronic control unit 50 is configured
to initiate the second closing operation 104 while monitoring the closing force and
to verify that the second threshold is exceeded or not.
[0054] If the second threshold is not exceeded, the electronic control unit 50 verifies
whether the target position has been reached. If the target position has not been
reached, the second closing operation 104 continues until the target position has
been reached and then the process ends. If the second threshold is exceeded during
the second closing operation 104 the electronic control unit 50 performs the second
reversing operation 105 and thereupon maintains the position of the window for a second
short period of time 106.
[0055] At the end of the second short period of time 106 the electronic control unit 50
initiates the third closing operation, preferably without applying a force limit.
The electronic control unit 50 verifies whether the target position has been reached
during the third closing operation 107 and ends the third closing operation 107 with
the window one in its target position when the electronic control unit 50 has detected
that the window in the target position and then the electronic control unit 50is ready
to receive new instructions.
[0056] The invention has been described in conjunction with various embodiments herein.
However, other variations to the disclosed embodiments can be understood and effected
by those skilled in the art in practicing the claimed invention, from a study of the
drawings, the disclosure, and the appended claims. In the claims, the word "comprising"
does not exclude other elements or steps, and the indefinite article "a" or "an" does
not exclude a plurality. The mere fact that certain measures are recited in mutually
different dependent claims does not indicate that a combination of these measured
cannot be used to advantage.
[0057] The reference signs used in the claims shall not be construed as limiting the scope.
1. An electrically operated actuator (10) for operating a window (1), said window comprising
a frame (2), a sash (3) being pivotally suspended from said frame (2) by a horizontal
pivot axis and, when pivoted, positioned in one of an open position zone (A), a near
closed position zone (B), and a visually closed position zone (C), a compressible
seal or gasket (5) being provided between said frame (2) and said sash (3) such that
it bridges at least a part of said visually closed position zone (C),
said actuator (10) being adapted to perform a first closing operation (101) while
monitoring an indicator of a closing force applied onto said sash (3) by said actuator
(10),
said actuator (10) further being adapted to initiate a first reversing operation (102)
upon said indicator of closing force exceeding a threshold during said first closing
operation (101), and said actuator (10) being configured to initiate a subsequent,
second closing operation (104) after said first reversing operation (102),
monitoring of said indicator of closing force being disengaged when said sash reaches
said visually closed position zone (C).
2. An actuator (10) according to claim 1, configured to monitor said indicator of closing
force during said second closing operation (104), adapted to initiate a second reversing
operation (105) upon said indicator of closing force exceeding a threshold during
said second closing operation (104), and further configured to initiate a subsequent,
third closing operation (107) after said second reversing operation (105).
3. An actuator (10) according to claim 2, adapted to perform at least one further reversing
operation upon said indicator of closing force exceeding a threshold, and at least
one further subsequent closing operation.
4. An actuator (10) according to any one of the previous claims, wherein said subsequent
closing operation (104, 107) is executed without monitoring said indicator of closing
force.
5. An actuator (10) according to any one of the previous claims, wherein said actuator
(10) is configured to apply the maximum closing force if needed during said subsequent
closing operation (104, 107).
6. An actuator (10) according to any one of the previous claims, wherein said actuator
(10) is driven by an electric drive motor (12) and said closing operation (101, 104,
107) is executed at at least one of a plurality of electric drive motor speeds.
7. An actuator (10) according to claim 6, wherein said electric drive motor (12) is operated
at a normal closing speed when said sash (3) is positioned in said open position zone
(A).
8. An actuator (10) according to claim 6 or 7, wherein said electric drive motor (12)
is operated at a decreased speed when said sash (3) is positioned in said near closed
position zone (B).
9. An actuator (10) according any one of claims 6 to 8, wherein said electric drive motor
(12) is operated at an increased speed when said reversing operation (102, 105) is
executed.
10. A method of closing a window by means of an actuator (10) according to any of claims
1 to 9, said window (1) comprising a frame (2), a sash (3) being pivotally suspended
from said frame by a horizontal pivot axis and, when pivoted, positioned in one of
an open position zone (A), a near closed position zone (B), and a visually closed
position zone (C),
said method comprising:
performing a first closing operation (101) while monitoring an indicator of a closing
force applied onto said sash (3) by said actuator (10),
initiating a first reversing operation (102) upon said indicator of closing force
exceeding a threshold during said first closing operation (101),
initiating a subsequent, second closing operation (104) after said first reversing
operation (102),
disengaging the monitoring of said indicator of closing force when said sash (3) reaches
said visually closed zone (C).
11. A method according to claim 10, further comprising performing a second closing operation
(104) while monitoring said indicator of closing force applied onto said sash (3)
by said actuator (10), initiating a second reversing operation (105) upon said indicator
of closing force exceeding a threshold during said second closing operation (104),
and initiating a subsequent, third closing operation (107) after said second reversing
operation (105).
12. A method according to claim 11, further comprising at least one further reversing
operation upon said indicator of closing force exceeding a threshold, and at least
one further subsequent closing operation.
13. A method according to claim 11, wherein said subsequent closing operation (104, 107)
is executed without monitoring said indicator of closing force.