Note: Descriptions are shown in the official language in which they were submitted.
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MOTORIZED SYSTEM FOR LATCHING AND UNLATCHING
CASEMENT WINDOWS
TECHNICAL FIELD
The application relates generally to casement windows and, more
particularly, to a motorized window latching system.
BACKGROUND OF THE ART
Casement windows are well known. Such windows typically have one or
more window sash pivotable about a vertical axis between an open and a closed
position. A latch bar is commonly employed to lock the window sash in its
closed
position in tight sealing engagement against the window frame. Such latch bars
generally include a flat steel strip having various latch points therealong
for
engagement with corresponding keepers provided along an edge of the associated
window sash. The latch bar is typically manually actuated by a pivotable lever
or lock
handle.
Heretofore, the motorisation of casement window latch mechanisms has been
challenging. In most instances, access to the window latch bar is difficult
and there is
very little room to position the motorized operator. Also the motorized latch
operator
must not adversely affect the aesthetic of the window in order for the product
to gain
commercial acceptance.
There is thus a need for a compact motorized latch operator that can be
integrated into a casement window without adversely affecting the appearance
thereof.
SUMMARY
It is therefore an object to provide a compact motorized latch operator that
can be integrated to a casement window.
In one aspect, there is provided a motorized latch operator adapted to be
retrofitted to a normally manually operated latching assembly of a casement
window
mounted in a building wall, the casement window having at least one window
sash
hingedly mounted in a casement for pivotal movement about a vertical axis
between
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open and closed positions, keepers being provided along one side of the window
sash
for engagement with corresponding latches mounted on a vertical side frame
member
of the casement, the latches being operatively interconnected by a vertical
latch bar
mounted for longitudinal movement in a gap defined between the side frame
member
and a moulding member; the motorized operator comprising a support frame
mounted
in a casing integrated to a building wall next to the casement, a reversible
rotary motor
hingedly mounted to the support frame, a lead screw drivingly connected to the
reversible rotary motor, a slider threadably engaged on the lead screw for
movement
therealong, a lever pivotally mounted at a first end portion thereof to the
support
frame, the slider being engaged with the lever to pivot the same in response
to a
movement of the slider along the lead screw, the lever being pivotally
connectable at a
second end portion thereof to the vertical latch bar to linearly displace the
same when
pivoted as a result of the movement of the slider on the lead screw.
In a second aspect, there is provided a power-operated latch assembly for a
casement window mounted in a building wall, the casement window having at
least
one window sash hingedly mounted in a window frame for pivotal movement about
a
vertical axis between open and closed positions; the power-operated latch
assembly
comprising at least two keepers mounted to the window sash for locking
engagement
with corresponding latches operated by a latch bar mounted for vertical
movement
along one vertical member of the window frame, a reversible operator mounted
to a
support frame disposed in the building wall adjacent to the casement window, a
lever
pivotally mounted to the support frame and having a first end drivingly
connected to
said reversible operator and a second end pivotally connected to the latch
bar, the
pivotal movement of the lever by the reversible operator causing the linear
movement
of the latch bar.
In a third aspect, there is provided a casement window comprising at least
one window sash hingedly mounted in a window frame for pivotal movement about
a
vertical axis between open and closed positions, a power-operated latch
mechanism
for releasably locking the at least one window sash in the closed position,
the power-
operated latch mechanism comprising at least two keepers mounted to the window
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sash for locking engagement with corresponding latches operated by a latch bar
mounted for vertical movement along one vertical member of the window frame, a
reversible rotary motor mounted in one of a cavity defined in the building
wall and an
internal cavity defined in the window frame, a vertically supported lead screw
drivingly connected to the reversible rotary motor, a vertically displaceable
slider
threadably engaged on the lead screw for linear movement therealong, and a
link
between the slider and the latch bar, the link transferring the movement
communicated
to the slider to the latch bar.
Further details of these and other aspects of the present invention will be
DESCRIPTION OF THE DRAWINGS
Reference is now made to the accompanying figures, in which:
Fig. 1 is a perspective view of a double hung casement type window as seen
from inside a room and having a motorized unlatching system mounted inside the
Fig. 2 is a perspective view of the motorized unlatching system together with
the window original latching hardware shown in isolation;
20 Fig. 3 is a cross-sectional view taken along line 3-3 in Fig. 1;
Fig. 4 is a longitudinal cross-sectional view illustrating the motorized
unlatching system in position in the central profiled post of the window
casement;
Fig. 5 is a perspective view of another model of double hung casement type
window, the vertical moulding along one side of the central post of the window
being
Fig. 6 is a vertical cross-sectional view illustrating the details of the
motorized latching system of Fig. 5;
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Fig. 7 is a perspective view of a single hung casement window, the vertical
moulding along one side of the window frame being omitted to reveal details of
a
motorized latching system connected to the original manual latching system of
the
window;
Fig. 8 is vertical cross-sectional view illustrating the details of the
motorized
latching system shown in Fig. 7;
Fig. 9 is a top plan view of a motorized unlatching system in accordance with
a further embodiment of the present invention;
Fig. 10 is a cross-sectional view taken along line 10-10 in Fig. 9;
Fig. 11 is a side view of the system shown in Fig. 9, and
Fig. 12 is a cross-sectional view taken along line 12-12 in Fig 11.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Fig. 1 illustrates a first example of a conventional casement window 10 to
which a motorized latching system or operator 12 can be integrated or
retrofitted to
provide for motorized latching and unlatching of the window. The illustrated
exemplary casement window 10 is of conventional double hung casement type
comprising a pair of window sashes 14 hingedly mounted in a casement 16 for
pivotal
movement between open and closed positions about mobile vertical axes at
opposite
sides of the casement 16.
The casement window 10 is provided with latching hardware to releasably
secure the window sashes 14 in their closed position. The latching hardware
can
comprise a plurality of keepers 18 (two in the illustrated example) on each
window
sash 14 for engagement with corresponding attachment points or latches 20
mounted
on opposed longitudinal exterior sides of the central profiled post 22 of the
casement
16. The latches 20 capture the keepers 18 and operation of the latches 20 draw
the
corresponding window sash 14 into its closed position where it is locked. In
the closed
position, the window sash 14 is seated in the frame and compresses weather
stripping
(not shown) to seal the window assembly. In the illustrated example, the
latches of
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each set of latches 20 are interconnected by a latch bar 24 adapted to
transmit the
movement from one latch to another, thereby allowing for joint operation of
the
latches 20 of a same set. The latch bars 24 are typically made from flat steel
strips
mounted for linear sliding movement against the exterior longitudinal sides of
the
central profiled post 22 of the casement 16.
Instead of manually actuating the interconnected latches 20 via a
conventional lever or handle provided at one of the latching points on each
side of the
central profiled post 22, it is herein proposed to nest a power-operated or
motorized
latch actuator system 12 in an existing frontal opening defined in the central
profiled
post 22 and to connect the system 12 directly to the existing latch bars 24 on
each side
of the central profiled post 22. Once installed, the motorized system 12 is
hidden
behind the front moulding (not shown) normally covering the post 22 when
viewed
from inside the room in which the window is mounted. By taking advantage of
the
existing free internal space offered by the central profiled post 22, it is
possible to
completely conceal the system 12 within the window casement 16, thereby
preserving
the overall appearance of the window.
As best shown in Fig. 2, the system 12 generally comprises at least one
reversible actuator, such as electrical reversible rotary motor 26, a push and
pull rod
which can take the form of a lead screw 28 drivingly connected to the motor
26, a
slider 30 threadably engaged on the lead screw 28 for linear movement within
the
profiled post 22 (Fig. 1) in the upward and the downward directions, and a
pair of link
plates 32 mounted to opposed sides of the slider 30 in order to rigidly
connect the
slider 30 to the lock bars 24 of the window 10. An example of a suitable
actuator is
the 12 DVC E Type Inline DC Gearmotor Model No. 8501 manufactured by Merkle-
Korff Industries. The dimensions of the selected actuator must allow the same
to be
fully contained within the central profiled post 22. The motor 26 is connected
to a
source of power (not shown), such as a battery. The lead screw 28 can consist
of a
stainless steel screw with ACME threads. The slider 30 can be manufactured in
a
block of polytetrafluoroethylene or from another solid block of low friction
material in
order to minimize the friction between the lead screw 28 and the slider 30.
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The system 12 further comprises a support 36 for supporting the motor 26
and the lead screw 28 and facilitating mounting of the system 12 within the
central
profiled post 22 of the casement window. The support 36 comprises an elongated
back
38 and top and bottom L-shaped plates 40 and 42 mounted at opposed ends of the
elongated back 38. The elongated back 38 provides a mounting surface for
fixedly
mounting the system 12 into central profiled post 22 of the casement 16. Holes
can be
defined through the back of the support 36 for receiving mounting screws or
the like.
The motor 26 is mounted to the undersurface of the bottom L-shaped plate 42. A
support block 41 having a screw receiving hole depends from the top L-shaped
plate
40 for receiving a tip end portion of the lead screw 28. Limit switches 46a,
46b and
46c are mounted to the front face of the support back 38 above and below the
slider
30. Projections 48a, 48b, 48c, such as screws, are provided on the top and
bottom
surfaces of the slider 30 to trigger the limit switches 46a, 46b and 46c when
the slider
30 reaches its top and bottom travel limits. The limit switches 46a, 46c are
operatively
connected to the motor 26 to shut down the same and reverse the direction of
movement once triggered by a corresponding one of the triggering projections
48a,
48c, thereby defining the range of motion or stroke of the slider 30 on the
lead screw
28. The third limit switch 46b is used as an interlock. The limit switch 46b
is
provided to prevent the motor (not shown) used to displace the window sashes
14
between their open and closed positions from being operated when the latches
20 are
engaged with the keepers 18. It is provided to "sense" the lock state of the
window
sashes. It can also be used to prevent the motor 26 of the power operated
latching
system from being operated when the window sashes are opened.
The motor 26, the lead screw 28, the slider 30, the support block 44 and the
limit switches 46a, 46b, 46c are pre-assembled on the support 36 and this sub-
assembly is mounted within the central profiled post 22, such as by screwing
the
support back 38 to a corresponding back surface of the casement window central
profiled post 22 . As shown in Fig. 4, the central post 22 is provided in the
form of an
extrusion having a generally C-shaped profile with a front open face. The
central post
22 has a frontal recess defined by sidewall surfaces 50 and inwardly
projecting frontal
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wall surfaces 52. The slider 30 has a generally T-shaped body including a
rearwardly
projecting shank portion 54 and lateral shoulders 56. The shank portion 54 is
received
between the frontal wall surfaces 52 of the profiled post 22 with the lateral
shoulders
56 resting against a front side of the frontal wall surfaces 52 between said
sidewall
surfaces 50. This arrangement prevents the slider 30 from rotating together
with the
lead screw 28. The slider 30 is thus constrained to move linearly in the
upward or the
downward direction depending whether the motor 26 is rotatably driving the
lead
screw 28 in the clockwise or the counter-clockwise direction.
Still referring to Fig. 4, it can be appreciated that the lock bars 24
interconnecting the latches 20 (Fig. 1) are guided in vertical tracks defined
at the outer
sides of the central profiled post 22. The link plates 32 are positioned
laterally
outwardly from the sidewall surfaces 50 of the post 22 and are fixedly
attached to the
lock bars 24 by fasteners such as screws or the like. Vertically elongated
slots 58 had
to be machined (also see Fig. 3) in the post sidewall surfaces 50 for allowing
the link
plates 32 to be rigidly connected to the slider 30 by means of shoulder screws
57. In
this way, the linear movement of the slider 30 inside the post 22 can be
simultaneously transmitted to both latch bars 24 on the opposed sides of the
central
profiled post 22. The length of the elongated slots 58 is selected to accept
the full
stroke of the slider 30 as set by the position of the limit switches 46.
In use, a remote control can be used to operate the system 12. A wireless
control receiver (not shown) can be mounted in the building wall underneath
the
window frame for receiving control commands and transmitting same to the
electric
motor 26. The rotational movement of the lead screw 28 causes the linear
displacement of the slider 30 which in turn push or pull on the lock bars 24
(depending in which direction the screw is rotated) to actuate the latches 20
in order to
lock or unlock the window.
If more torque is required to operate the latches, a second motor and a second
lead screw could be added to the above described latch operator assembly. The
second
motor could be mounted to the top L-shaped plate 40 of the support with the
second
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lead screw laterally offset with respect to the first lead screw 28. The
motors would be
synchronized but operated to drive the first and second lead screws in opposed
directions.
Figs. 5 and 6 illustrate another example of the integration of a motorized
latch actuation system 12' to a double hung type casement window 10' but this
time
for a model of window having a solid central post 22' having no internal
cavity in
which the above described components of the motorized latching system could
potentially be mounted. The only space available to access the lock bars 24'
is the 3/4
inch to 1 inch gap existing between the central post 22'and the vertical
moulding 23
on each side of the post 22'. This does not leave enough room to accommodate
the
motor.
The motor 26' had thus to be disposed in a rectangular wooden box or casing
27 mounted to the casement 16' underneath sill 29. The casing 27 forms a
hollow
window frame extension for receiving window operator equipment and the like.
The
motor 26' is thus concealed in the building wall below the original window
frame.
The dimensions of the casing 27, notably the height thereof, are greatly
limited by the
presence of the structural or skeleton members of the building wall in which
the
window is mounted. In view of the small space available underneath the
casement
window 10', the motor 26' is horizontally disposed in the casing 27 and a
universal
joint 31 is used to connect the motor 26' to the lead screw 28' extending
vertically
along the side of the central post 22' in the gap defined between the side
moulding 23
and the central window post 22'.
The lead screw 28' extends through a hole 33 defined in the window sill 29
and is vertically supported by a bottom support block 37 mounted to the
central post
22' underneath the sill of the window 10'. As shown in Fig. 6, the lead screw
28' has
a shoulder resting on top of the bottom block 37 to prevent the screw 28' from
sliding
downwardly under gravity into the lead screw passage defined in the bottom
block 37.
The upper end or tip of the lead screw 28' is received in a hole defined in a
top
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support 44' screwed or otherwise secured to the side of the central post 22'.
The top
support 44' is also contained in the gap between the post 22' and the moulding
23.
The limit switches 46a', 46b' and 46c' are also directly mounted to the side
of the post 22' below the internally threaded slider 30' mounted on the lead
screw 28'
in the gap between the post 22' and the moulding 23. A L-shaped triggering
finger 39
extends downwardly from the slider 30' for triggering the limit switches 46a',
46b'
and 46c' when the slider 30' reaches the end of its stroke.
The mounting of the slider 30' against the side wall of the central post 22'
locks the slider 30' against rotation and constrains the slider 30'to move
linearly along
the side wall of the post 22' in response to the rotation of the lead screw
28'. An
elongated strip or rod 41 extends upwardly from a post facing side of the
slider 30' in
order to rigidly connect the same to the existing lock bar 24' interconnecting
the
latches 20' of the window 10'. The linear movement of the slider 30' on the
lead
screw 28' can thus be transferred to the existing lock bar 24' in order to
latch and
unlatch the window.
It is understood that a similar motorized latch operator is provided on the
other side of the central post to operate the lock bar interconnecting the
latches
associated to the second window sash (not shown).
Figs. 7 and 8 illustrate another example of the integration of a motorized
latch actuation system 12" to an originally manually actuated latching system
of a
single hung type casement window 10". In this example, the window lock bar 24"
interconnecting the latches 20" on one side of the window frame is disposed
further
towards the outside of the room in which the window is mounted. The casing 27"
secured underneath the window frame in the building wall and holding the motor
26'
is not aligned with the lock bar 24". The casing 27" is located further
towards the
inside of the room relative to the lock bar 24". As will be seen herein after,
this
misalignment problem is overcome by connecting the motorized system 12" to an
existing link 70 originally joined to the lever/handle (not shown) of the
lower manual
latch 20".
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As shown in Fig. 8, the motor 26' is horizontally mounted in casing 27"
which is disposed in the building wall underneath the window frame. The motor
26"
is drivingly connected to a vertically disposed lead screw 28" via universal
joint 31".
The lead screw 28" extends through a hole defined in the window sill and has a
top
head 71 retained captive between a base 72 and a cover 74. The base 72 and the
cover
74 are made of a low friction material and are used to support the lead screw
28"in
position. The base 72 is mounted on a top surface of the window sill and has a
through bore defined therein for allowing the lead screw 28" to pass
therethrough. A
recess is defined in a top surface of the base 72 for receiving a split washer
76. The
washer 76 is mounted about the lead screw 28" underneath head 71. The cover 74
has
a recess defined in an undersurface thereof for accommodating the screw head
71 and
is screwed or otherwise suitably secured to the base 72. A horizontal moulding
(not
shown) covers the sill of the window to conceal the base 72 and the cover 74.
A low frictional material rectangular sleeve 78 is installed in the hole
defined
in the window sill to provide for smoothly guided movement of slider 30" on
the lead
screw 28". The sleeve 78 is configured to lock the slider 30" against rotation
while
providing for smooth linear gliding movement therein. An elongated flattened
rod or
strip 80 is attached to the slider 30" and extends vertically upwardly through
aligned
slotted holes defined in the base 72 and cover 74. The upper end of the strip
80 is
pivotally connected to existing link 70 which is, in turn, connected to the
lock bar
24" joining all the latches 20" of the window. The pull and push strip 80 can
be
guided at the upper end thereof by a guide 82 mounted to the side member of
the
window frame on which the latches 20" are mounted. The vertical moulding (not
shown) of the side member of the window frame conceal all the mechanism
disposed
therealong.
As shown in Fig. 7, the limit switches 46a", 46b", 46c" are mounted on the
side of the frame next to the upper latch 20" so as to be triggered by the
components
thereof.
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Figs. 9 to 12 illustrate another example of a motorized latch actuation system
120 adapted to be mounted in a hollow casing (not shown) secured underneath a
window frame in a building wall. The system 120 comprises a support frame 136
including a base plate 136a adapted to be screwed or otherwise suitably
securely
mounted to the bottom wall of the casing underneath the window frame. The
support
frame 136 further comprises a pair of side plates 136b extending integrally
upwardly
from the base plate 136a. A lever 132 is pivotally mounted to side plates 136b
for
rotation about a generally horizontal axle 137 extending transversely through
the side
plates 136b and the lever 132. The lever 132 has an arm portion 132a
projecting away
from one end of an inverted U-shaped end portion 132b mounted between the side
plates 136b of the support frame 136. The side plates 136b and the U-shaped
end
portion 132b have registering holes for receiving the axle 137. The distal end
of the
arm portion 132a of the lever 132 has an elongated slot 132c (Fig. 11) adapted
to
receive a fastener 133 for pivotal connection to a latch bar extension 141
adapted to be
rigidly connected to bottom end of the latch bar (not shown) of the window. In
this
way, the lever 132 can be rotated about the axle 137 to linearly displace the
latch bar
extension 141 and, thus, the latch bar in an upward or a downward direction
(see
arrows A in Fig. 11) in order to lock or unlock the window. The length of the
arm
portion (distance between the axle 137 and the elongated slot 132c) is
selected to
provide the desired levering force.
As best shown in Figs. 9 and 11, a pair of low friction pads 139 is fixedly
mounted to the inwardly facing side of the U-shaped end portion 132b of the
lever 132
for engagement with a slider 130 which is, in turn, threadably engaged on a
lead screw
128 driven by a reversible rotary motor 126. The slider 130 is trapped between
the low
friction pads 139 and has cylindrical projections 130a extending laterally
therefrom
for engagement in corresponding cylindrical holes defined in the pads 139.
This
arrangement allows for relative angular movements between slider 130 and the
pads
139 (and, thus, the lever 132) when the slider 130 moves along the lead screw
128 in
response to a torque being applied thereto by the motor 126. The distance
between the
cylindrical projections 130a of the slider 130 and the pivot axis of the lever
(i.e. the
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axle 137) is also selected as a function of the desired levering force for
operating the
latch bar.
As shown in Figs. 10 and 11, the motor 126 is mounted to a support 126a
which is, in turn, hingedly mounted to the base plate 136a of the support
frame 136.
For instance, the support 126a may be rigidly connected to a first hinge plate
139a
pivotally connected at 139c to a second hinge plate 139b fixed to the top
surface of
the base plate 136a at the rear end of the motor 126.
As shown in Figs. 9 and 11, limit switches 146a and 146c are mounted to the
inwardly facing surface of one of the side plates 136b of the support
structure 136 and
are disposed to be triggered by the inverted U-shaped portion 132b of the
lever 132
when the same is pivoted by the slider 132 to its limit positions on axle 137.
In operation, the motor 126 may be powered to linearly displace the latch bar
of the window between locked and unlocked positions. The rotation of the lead
screw
128 causes the slider 130 to move therealong, thereby causing the lever to
pivot about
axle 137 has indicated arrows B in Fig. 11. The hinge connection between the
motor
126 and the support frame 136 allows to accommodate the pivotal movement of
the
lever 132 and, thus, of the slider 130 relative to the axle 137. As a result,
the arm
portion 132a of the lever 132 is pivoted as depicted by arrows C in Fig. 11 to
upwardly or downwardly linearly displace the latch bar extension 141 together
with
the latch bar (not show) connected thereto.
It is understood that the arm portion 132a of the lever could extend in a
direction opposite to the direction illustrated in Figs. 9 to 11. That is the
arm portion
132a could extend axially in a direction away from the motor 126 forwardly
relative to
the lead screw 128. The forwardly or rearwardly projecting configuration may
be
selected depending on the space available in the hollow casing underneath the
window
frame.
The above description is meant to be exemplary only, and one skilled in the
art will recognize that changes may be made to the embodiments described
without
departing from the scope of the invention disclosed. Modifications which fall
within
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the scope of the present invention will be apparent to those skilled in the
art, in light
of a review of this disclosure, and such modifications are intended to fall
within the
appended claims.
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