Note: Descriptions are shown in the official language in which they were submitted.
CA 02561026 2006-09-27
GARAGE DOOR OPENER
FIELD OF THE INVENTION
The present invention relates to garage door openers. More specifically, the
invention relates to garage door operating systems for the secure motorised
s opening and closing of a garage door without the use of a counterbalance
device.
BACKGROUND OF THE INVENTION
Several garage door operating systems are currently commercially available. In
many of these manual and motorised garage door operating systems, most of the
opening and closing of the garage door is done by a counterbalance system
using
to torsion or linear extension springs or by a system of counterweights, and
not by
the human operator or motor drive mechanism. Linear extension springs are
mounted on either side of a door and are mainly used on single-car garage
doors
whereas torsional springs are mounted to the header above the top of the door
and are used on heavier double-car garage doors. Such counterbalance-assisted
Is garage door operating systems require less force to open and close the door
and
allow for the partial opening and closing of the door.
There are basically two-types of motorised operators: trolley and jackshaft.
A trolley operator is used for most vertically-opening sectional garage doors.
In a
trolley operating system, a motor drive is mounted above the door in the
center of
2o the garage ceiling and a rail guides a trolley across the ceiling to and
from the top
of the garage doorway. As the trolley moves along the rail, the top section of
the
door is pushed or pulled thereby causing the door to close or open. The motor
drive used in trolley operators is one of three basic types: chain drive, belt
drive
and screw drive. Chain drive systems use a metal chain along with a metal
trolley
2s to lift the door up and down along its tracks. Belt drive systems are
similar to
chain drive systems. They use flexible steel reinforced rubber belts to move
the
CA 02561026 2006-09-27
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trolley along the rail, which dampen the vibrations and eliminate the noisy
metal-
to-metal contact of chain drive systems. Screw drive systems lift the garage
door
using a threaded steel rod encased in the rail mechanism. The main body of the
opener is situated in the center of the garage ceiling, the rail guides the
trolley and
s the threaded steel rod pushes the trolley. In general, these systems open
and
close a garage door more slowly than a chain or belt drive system, but can
apply
more force and thus are more powerful.
One major disadvantage of trolley operators stems from the fact that the
operator
usually hangs in the center of the garage ceiling - it is often encumbered
with
to obstacles running along the ceiling (beams, pipes, etc.) or becomes an
obstacle
itself to the smooth operation of the door. if the trolley knocks into an
obstacle, the
door may be prevented from opening and closing properly: for example, the
chain
of the chain drive may become entangled preventing the trolley from moving
along
the rail. Moreover, trolley operators are not suited for garages with high
ceilings
Is such as is often the case for industrial settings.
A jackshaft operator uses a motor drive to turn the shaft of a torsional
spring
counterbalance system. This type of garage door operator does not require an
overhead rail; the opener is situated to the side of the door. However, the
more
forceful torsional springs are under tremendous tension and can be extremely
2o dangerous if tampered with. This type of system also tends to lack the
required
safety features that stop the doors from crushing objects in their paths and
cause
the doors to reverse direction if they strike something.
Furthermore, to ensure the smooth operation of these counterbalance-assisted
garage door operating systems, the costly springs must be well maintained
zs through regular lubrication. Although these counterbalance-assisted garage
door
operating systems allow the use of low-cost low-power motor drives, the cost
to
replace tired or broken springs is significant; the stronger the spring the
greater the
cost. In addition, extension springs must be balanced to pull on both sides of
the
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door with the same force and torsion spring assemblies are heavy, awkward to
handle, and difFicult to install safely.
Moreover, should the counterbalance device of current motorised counterbalance-
assisted garage door operating systems fail, the motor in most of these
systems -
s generally of low power and being made of low-cost, low-quality material and
therefore not being robust - would not be able to support the load of the
garage
door or operate the door safely and efficiently on its own.
Numerous garage door systems or the like are specified and known in the art.
US Patent No. 1,047,131 discloses a grain car door made of a number of
to superposed panels and a system for locking the door panels in an elevated
or
inoperative position, and for releasing the panels to permit them to return to
a
lower position. The system is manually driven. Rotation of a pawl-and-ratchet
wheel mechanism rotates a cable drum, which in turn winds or unwinds the
cables
attached to the bottom panel of the door thereby lifting or lowering the
panels of
is the door. This system requires a complex rail system in order to be able to
lift and
lower only certain panels of the grain door.
US Patent No. 2,277,932 discloses a door operating mechanism adaptable to
garage doors. The disclosed mechanism uses a motor connected to a cable drum
and a single cable wound thereon. The motor is mounted inside the garage on a
2o platform protruding from the garage wall above the door with the cable drum
positioned midway between the vertical door guide rails. A peculiar
arrangement of
the cable and pulley system with respect to the door that exerts equal force
on
either side of the door and thrusts inwardly the upper portion of the door to
relieve
the motor of undue strain is needed to open the door efficiently and without
2s jamming.
US Patent No. 2,598,709 discloses a mechanism for operating a closure for an
opening which includes a ceiling-mounted motorised trolley operator connected
to
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a cable-operated door. A main disadvantage of this door operating system lies
in
the required ceiling mounts.
US Patent No. 2,612,371 discloses an overhead garage door operator mounted
over the top of the door that uses a motorised winch mechanism and a system of
s wound cables to lift and lower a garage door. This system also uses pivoted
link
means for controlling the inward tilting movement of the door as it is lifted.
Drawbacks of this system include the need for vertical and overhead clearance
and the significant risk of entanglement of the cables involved.
US Patent No. 3,756,585 discloses a spiral spring counterbalance unit for
lifting an
to overhead door having a pair of interconnected cable drums which are
actuated
simultaneously by a single spiral spring element, whereby the drum cables
apply
equal lifting forces at each side of the door to be lifted.
As such, there is a need for a simple, secure, low-maintenance and long-term
cost-efficient garage door operating system that can open and close large
heavy
Is doors as well as small light doors without the use of counterbalance
systems and
that is not encumbered by entangled chains and obstacles along the ceiling of
a
garage.
SUMMARY OF THE INVENTION
In accordance with one aspect of the present invention, there is provided a
garage
ao door operating system for opening and closing a garage door which is
located in a
wall and has opposite top and bottom ends, and opposite sides. The garage door
operating system includes a two-channel cable drum having two channels of a
single-cable width and a rotation axis. The garage door operating system
further
includes a first and a second length of cable each having a first end attached
to a
2s respective one of the opposite sides of the garage door, and a second end
attached to a respective one of the two channels of the two-channel cable
drum, a
cable-guiding assembly positioned for guiding the first and second length of
cable
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between the two-channel cable drum and the opposite sides of the garage door,
and a motor comprising a driveshaft directly rotatably connected to the
rotation
axis of the two-channel drum, whereupon a rotation of the driveshaft opens or
closes the garage door by winding or unwinding the first and second length of
s cable onto or off of the two-channel cable drum, the motor having a strength
sufficient to open the garage door without the aid of a counterbalance device.
Preferably, the cable drum is mounted on the wall adjacent one of the opposite
sides of the garage door.
In an embodiment of the garage door operating system, the cable-guiding
to assembly preferably includes at least one primary pulley operatively
located after
the two-channel cable drum and mounted proximate the top end of the garage
door adjacent to the garage door. The cable-guiding assembly may also
preferably
include at least one secondary pulley mounted operatively after the primary
pulley
at right angles to the primary pulley.
~s Preferably, the garage door operating system may include an attachment
fixture
attached to each of the opposite sides of the garage door for fixing the first
end of
each of the first and second length of cable to the respective one of the
opposite
sides of the garage door.
Also preferably, the garage door operating system may include a cable
tensioner
2o for detecting cable slack connected to the first and second length of
cable. In
addition, it may include a limit switch connected to the motor for stopping
the
motor.
In accordance with another aspect of the present invention, there is provided
a
garage door operating kit for use in opening and closing a garage door having
2s opposite top and bottom ends, and opposite sides. The garage door operating
kit
includes a two-channel drum having two channels of a single-cable width and a
rotation axis. The garage door operating kit further includes a first and
second
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length of cable each having a first end attachable to a respective one of the
opposite sides of the garage door, and a second end attachable to a respective
one of the two channels of the two-channel cable drum, a cable-guiding
assembly
for guiding the first and second length of cable between the two-channel cable
s drum and the opposite sides of the garage door, and a motor comprising a
driveshaft for direct rotary connection to the rotation axis of the two-
channel drum,
whereupon in use a rotation of the driveshaft opens or closes the garage door
by
winding or unwinding the first and second length of cable onto or off of the
two
channel cable drum, the motor having a strength sufficient to open the garage
Io door without the aid of a counterbalance device.
In an embodiment of the garage door operating kit, the cable-guiding assembly
preferably includes at least one primary pulley. The cable-guiding assembly
may
also preferably include at least one secondary pulley for ensuring the non-
entanglement of the first or second length of cable.
is Preferably, the garage door operating kit may include an attachment fixture
for
fixing the first end of each of the first and second length of cable to a
respective
one of the opposite sides of the garage door.
Also preferably, the garage door operating kit may include a cable tensioner
for
detecting cable slack connectable to the first and second length of cable. In
2o addition, it may include a limit switch connectable to the motor for
stopping the
motor.
Advantages of the present invention include a garage door operating system
that
is simple, secure, easy to maintain, and does not require counterbalance
devices.
The objects, advantages and other features of the present invention will
become
2s more apparent and be better understood upon reading of the following non-
restrictive description of the preferred embodiments of the invention, given
with
reference to the accompanying drawings. The accompanying drawings are given
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7
purely for illustrative purposes and should not in any way be interpreted as
limiting
the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a front view of a garage door operating system as it would appear
in
s use (motor not shown for sake of clarity), according to a preferred
embodiment of
the invention. Note that the two-channel cable drum is shown in cross-section
illustrating the winding of a length of cable in one of the two channels.
Figure 2 is a cross-section view of the two-channel cable drum, illustrating
the
superposed winding of a length of cable in one of the two channels of single-
cable
to width, according to a preferred embodiment of the invention.
Figure 3 is a front view of a motor of the garage door operating system
illustrating
the rotary connection between the driveshaft of the motor and the two-channel
cable drum, according to yet another preferred embodiment of the invention.
DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION
Is The present invention will be described more fully hereinafter with
reference to the
accompanying drawings, Figures 1, 2, and 3, in which like numerals refer to
like
elements throughout.
The present invention provides a garage door operating system for opening and
closing a garage door (10) and a kit for installing such a system. Figure 1
depicts
2o most of the elements of a preferred embodiment of the system as installed
for
operation.
The garage door (10) is preferably of an industrial type, for example, such
garage
doors as found in factories and plants of different kinds, large
apartment/condominium complex garages, autobody/mechanic shops and
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8
underground shopping mall parking. Of course, this does not preclude the
garage
door (10) from being of a residential type, for example the garage door of a
single-
family home. It may be of a typical single- or double-car width. It may be
either a
heavy or light door made of a single section or of several panel sections. The
door
s (10) has opposite top (11) and bottom (13) ends and opposite sides, i.e. a
left side
(15a) and a right side (15b). It may have rollers attached along its left and
right
sides (15a and 15b) which engage rails fixed to the garage wall (17) on either
side
of the door (10) - the rollers and rail system guiding the door (10) up or
down as it
is opened or closed. As shown in Figure 1, it is preferably a single-section,
to vertically-opening, overhead door. Nevertheless, as one versed in the
domain
would understand, the elements of the invention may be adaptably applied to
any
type of door, from a single-section or multi-section overhead door to a
sectional
horizontally-sliding door.
With reference to Figures 1, 2, and 3, the garage door operating system
includes a
Is two-channel cable drum (12), two lengths of cable (20), a cable-guiding
assembly
and a motor (30). It is to be noted that in Figure 1, for sake of clarity, the
motor
(30) is not shown and the two-channel cable drum (12) is shown in cross
section.
For ease of assembly and installation, the two-channel cable drum (12), along
with
some of the other elements of the garage door operating system which will be
2o described below, is preferably mounted on a flat plate (18) and it is this
flat
plate (18) which is directly secured to the garage wall (17). Regardless, the
two-
channel cable drum (12) is preferably secured to the garage wall (17) on
either
side of the door (10) near the top of or above the door (10), and thus does
not
hinder the opening and closing of the garage door (10). Of course, it should
be
2s understood that the two-channel cable drum (12) may be mounted directly or
indirectly to the garage wall (17) above the door (10) or practically anywhere
along
the garage wall (17), providing the system of the present invention great
versatility
with respect to its installation when compared to prior art designs. It has
two
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grooves or channels (14) of a single-cable width for superposed winding of
cables,
and a rotation axis (16).
Each length of cable (20) may be made of a material of high tensile strength
such
as stainless steel. The two lengths of cable (20) may be two separate cables
or
s two sections of a single cable. One end of each length of cable (20) is
attached to
a respective one of the two channels (14) of the two-channel cable drum (12).
In
this way, each length of cable (20) is wound around its respective single-
width
cable channel (14) in a superposed single-width coil. Figure 2 provides a
cross-
section of the two-channel cable drum (12) showing the superposed winding of a
~o length of cable (20) in a channel (14) of the cable drum (12). The other
end of
each length of cable (20) is attached to a respective one of the opposite
sides of
the garage door (10). For example, the other end of the first length of cable
(20) is
attached to the bottom right side (15b) of the door (10) while the other end
of the
second length of cable (20) is attached to the bottom left side (15a) of the
Is door (10). This end of each length of cable (20) which is attached to the
door may
advantageously be provided with attachment means, such as a hook or a loop.
Preferably, a cable attachment fixture (22) adaptably attached to the door and
to
which the end of the length of cable (20) may be secured is also included. The
attachment fixture (22) may be an appropriate corresponding cable attachment
Zo means, such as a loop or an eyelet attached directly to the door or to
existing
hardware of the door for engaging a hook attached to the end of the length of
cable (20).
A cable-guiding assembly for guiding the first and second lengths of cable
(20)
between the two-channel cable drum (12) and the cable attachment fixtures (22)
2s on the garage door (10) is provided.
The cable-guiding assembly preferably includes at least one primary pulley
(24).
According to the preferred embodiment of Figure 1, the first length of cable
(20)
CA 02561026 2006-09-27
coming from the cable drum (12) is guided by a first primary pulley (24)
rotatably
mounted onto the flat plate (18) above the two-channel cable drum (12) down to
the cable attachment fixture (22) on the right side (15b) of the door (10),
and the
second length of cable (20) from cable drum (12) is guided by the first
primary
s pulley (24) to a second primary pulley (24) mounted on a flat plate (28)
(for ease of
assembly and installation as explained above) secured to the garage wall (17)
and
in turn guided by the second primary pulley (24) down to the attachment
fixture
(22) at the bottom of the opposite left side (15a) of the door (10). In the
preferred
embodiment of Figure 1, the first primary pulley (24) is a two-channel pulley
able
to to guide the two lengths of cable (20) separately, thereby avoiding
possible
entanglement of the two lengths of cable (20) and helping the smooth and
efficient
operation of the garage door operating system.
In addition, the cable-guiding assembly advantageously may include one or more
secondary pulleys (26) mounted operatively after the primary pulley (24) for
further
is ensuring the non-entanglement of the two lengths of cable (20) as they are
guided
from the cable drum (12) to the cable attachment fixtures (22). Figure 1 shows
two such secondary pulleys (26) mounted directly underneath each primary
pulley
(24), at right angles to their respective primary pulley (24), with their
faces at right
angles to both the garage wall (17) and ceiling, guiding the two lengths of
cable
ao (20) down to the attachment fixtures (22).
For operatively opening and closing the garage door (10), a motor (30) having
a
sufficient strength to operate the garage door (10) without the aid of a
counterbalance device is provided. For the sake of clarity, the motor (30)
itself and
the connection of the motor (30) to the cable drum (12) along with any
additional
2s mounting support is not shown in Figure 1. Nevertheless, in Figure 3, it
can be
seen that the driveshaft (32) of the motor (30) is directly rotatably
connected to the
rotation axis of the two-channel cable drum (12). While the motor (30) is
powered
on, actuation of the garage door opening system causes a rotation of the
driveshaft (32). Rotation of the driveshaft (32) in a given direction results
in the
CA 02561026 2006-09-27
11
rotation of the two-channel cable drum (12) and the winding of the first and
second
lengths of cable (20) onto the cable drum (12) thereby opening the garage
door (10). Rotation of the driveshaft (32) in the opposite direction results
in the
rotation of the two-channel cable drum (12) in the opposite direction and the
s unwinding of the first and second lengths of cable (20) off of the cable
drum (12)
thereby closing the garage door (10).
Of course, although the motor (30) and two-channel cable drum (12) are
preferably mounted on the garage wall (17) to the side and above the door in
the
embodiment of Figure 1, one of the advantages of the operating system is that
the
to motor (30) and cable drum (12) drive unit may be mounted at almost any
position
on the garage wall (17) with the use of pulleys to guide the cables as needed
from
the cable drum (12) to the attachment points on the door (10).
As mentioned, the motor (30) must have a sufficient strength to operate the
garage door (10) without the aid of such counterbalance devices as extension
or
is torsional springs. Motors typically used with counterbalance-assisted
systems
usually do not have enough strength to lift and operate the door in cases
where
the counterbalance system should fail. In general, a large sectional
industrial
garage door, 20 foot by 20 foot in area may weigh up to 1 600 Ibs
(approximately
725 kg) whereas a small residential garage door (9 foot by 7 foot) may weigh
as
20 little as 100 Ibs (approximately 45 kg). Preferably, the motor (30) is a 3
HP
(3 horse power) motor capable of lifting a maximum load of approximately 725
kg
(1 600 Ibs) through 18 feet at a speed ranging from 6 to 30 seconds. It
preferably
and advantageously is capable of 1 000 cycles a day, that is to say, it may be
used to open and close a door up to 1 000 times a day. According to an
2s embodiment of the motor (30), the motor (30) is approximately 37 cm (14.5
inches)
in width and 76 cm (30 inches) in height and is encased in a housing which
protects its working elements from the environment (for example from the
corrosive fumes and dust found in industrial underground parking garages) and
allows for little to no maintenance of the motor. The conventional motor of a
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counterbalance-assisted garage door operating system would not be able to
sustain such rigorous use for more than a few months.
If the garage door (10) should encounter an obstacle as it is being opened or
s closed, the garage door operating system advantageously can provide a safety
mechanism (34) connected to the first and second lengths of cable (20). The
safety mechanism (34) is preferably installed at a point before the two
lengths of
cable (20) are split and guided to their respective cable attachment fixtures
(22).
The safety mechanism (34) preferably includes a cable tensioner (36) for
detecting
~o any slack in either of the two lengths of cable (20), and a limit switch
(38)
connected to the motor (30) for stopping the motor. When the cable tensioner
detects slack in either of the two lengths of cable (20), as would be the case
if the
door (10) were to encounter an obstacle mid-operation, it triggers the limit
switch
(38) switching off the motor (30) and preventing the obstacle from being
crushed
~s and the operating system from being damaged.
It should be noted that the scale of the objects in Figure 1 is not accurate.
Certain
elements, such as the two-channel cable drum (12), and lengths have been
enlarged in the drawing for the sake of clarity. A person skilled in the art
will also
comprehend equivalents - that minor changes in the size, form and construction
of
2o the various parts may be made and substituted for those shown herein
without
departing from the scope of the invention.
Because of the versatile positioning of the motor (30) and cable drum (12)
along
the garage wall (17), specifically their positioning to the side of the garage
door
(10), and the lack of ceiling mounts, this garage door operating system is
2s appropriate for garages and garage doors lacking overhead clearance. In
addition, the two-channel cable drum (12) with its single-cable width channels
(14)
along with the primary and secondary pulleys, ensure that the cables do not
become entangled and consequently the smooth, secure and proper operation of
the garage door operating system.
CA 02561026 2006-09-27
13
Another advantage of this system is its low maintenance. Other than the motor,
this system relies on only a few moving parts and therefore requires minimal
maintenance. There are no springs to be regularly lubricated, calibrated or
replaced. Whereas the motor required for this system may cost more upfront
than
s those used with counterbalance devices, in the long run the cost of
operation is
less when one factors in the cost of spring replacement and maintenance of the
counterbalance-assisted systems.
Furthermore, in order to be able to lift the more heavy doors, conventional
counterbalance-assisted systems require more powerful and therefore more
costly
to springs. In the case of powerful torsional springs, with the cost of
maintenance
comes the added safety concern. Calibration or replacement of torsional
springs
must be effected carefully by skilled workers. Moreover, torsional spring
systems
generally cannot detect when the door is crushing an obstacle, for example a
car
or person. Advantageously, the garage door operating system of the present
is invention does not require use of costly and potentially dangerous springs,
but
rather provides a powerful motor, typically two to three times more powerful
than
conventional counterbalance-assisted motors, and a desired safety mechanism
which will halt the motion of the door should the door come into contact with
an
obstacle.
2o Conventional garage door operating systems do not invest in powerful motors
-
they use low-cost low-power motors and consequently need a counterbalance
system to be able to open and close a garage door. It is to be understood that
a
counterbalance-assisted garage door operating system is a system that uses a
counterbalance force to balance the load of the garage door and/or reduce the
2s work that must be done by the operator, be it a human operator or a motor
operator, to open and/or close the door. For example, the counterbalance force
in
most counterbalance-assisted garage door operating systems is provided by
springs (for example, torsion or linear expansion springs) or weights (also
referred
to as counterweights) and may include block and tackle pulley systems.
CA 02561026 2006-09-27
14
The present garage door system uses the brut force of a powerful motor and
thereby eliminates the need for a counterbalance device to open and close a
garage door, even when this door is one of the more heavy industrial garage
doors. Advantageously, the number of components and the maintenance required
s to ensure the efficient and secure operation of the system is reduced. In
addition,
all of this makes the present system more versatile when it comes to mounting
the
system since the geometry of the layout of the elements of the system is not
restricted by the use of counterbalance devices such as springs and is
therefore
adaptable to various types of garages, including garages with low overhead
to clearance and garages with extremely high ceilings, garages where the door
lifts
up vertically or slides across horizontally to open.
Numerous modifications could be made to any of the embodiments described
above without departing from the scope of the present invention as defined in
the
appended claims.
