Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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SPRING BREAK DEVICE
Field of the invention:
The present invention relates to a "spring break device" which is a braking
device for use with garage doors and the tike. More particularly, the present
invention relates to a braking device configured for use with a
counterbalancing
system of a door, such as a garage door for example. The present invention
also
relates to a counterbalancing system provided with such a braking device and
to a
kit for assembling the braking device. The braking device is intended to hold
the
garage door in position in case of a failure in the counterbalancing system,
thus
ensuring that the garage door does not fall ail the way down and does not
cause
serious damages to property or serious injuries.
Background of the invention:
Garage doors and the like are well known in the art. Indeed, it is well known
in the art that garage doors usually require to be connected to a
counterbalancing
system for counterbalancing the weight of the door in order to decrease the
force
required to open the door and also safely facilitate its closing from a raised
to a
lowered position. Counterbalancing systems can be found in many other types of
cable-operated doors, such as slidable truck doors for example.
It is also known in the art that a widely used type of counterbalancing
system generally comprises a pair of spaced apart cable drums connected to
corresponding cables, each cable being in turn connected to a lower opposite
side
edge of the garage door. The cable drums are usually mounted on an overhead
shaft which is supported above the door opening and is connected to one or
more
torsion springs which are each fixed to the shaft at one end, and operatively
secured to a fixed structure such as the wall, or a wall bracket for example,
at the
other end, so that the cable drums are biased to rotate in a direction which
winds
the cables onto the drums and counteracts the weight of the door connected to
the
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cables. The torsion springs are adjusted to properly balance the weight of the
door
so that minimal opening and closing efforts are required, either manually or
when
motor controlled.
It is also known in the art that conventional, low cost adjustment devices
used for the above-mentioned type of counterbalancing system, and widely
utilized
in the garage door industry, are generally cylindrical "collars" commonly
referred to
also as "plugs" (or "cones") which are connected to the ends of the torsion
springs
and are thus mounted on the aforementioned shaft for adjusting the deflection
of
the springs to preset the torsional (or counterbalancing) force of the spring.
In operation, torque is transferred between the torsion spring, overhead
shaft, and plugs which operatively connect the shaft to the spring, in order
to
counterbalance the weight of the garage door. Usually, each torsion spring is
fixed
to the overhead shaft at one end, by means of a plug known as a "winding
plug",
and operatively secured to the wall via a bracket at the other end, by means
of
another plug known as a "stationary plug":
It is also known in the art that occasionally, for one reason or the other,
although very unlikely, one of the counterbalancing springs brakes or one of
the
elements connected to such counterbalancing springs undergoes failure, leading
to the garage door falling al! the way down, which may cause damages or
injuries.
Indeed, the failure of a counterbalancing system usually results in the free
falling
of the door and thus may possibly result into an undesirable result.
There have been many attempts to come up with safety braking devices
which are used for slowing descent of a garage door andlor immobilizing the
garage door in the event of a failure in its counterbalancing mechanism.
Known to the Applicant are the following patents and patent applications
which describe various devices for use with garage doors and the like:
WO 03/0787773 (CANIMEX) published September 25t", 2003;
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DE 201 12 521 U (NOVOFERM GMBH) published November 29~", 2001;
EP-A-1 213 428 (FLEX/ FORCE BV) published June 12t", 2002;
DE 9310 792 U (H(SRMANN KG) published June 30t", 1994;
DE-A-44 12 421 (SCHIEL, HANS-JOSEF) published November 2"d,1995.
It is also known that on existing spring break device systems, there are no
method to assure that the ratchet system is properly aligned during all life
of the
product. Therefore, there is a need for a device which assures proper
alignment by
forcing the ratchet wheel to keep its positron during use of the product.
Also, another problem of existing spring break devices is the fact that
human interaction is required to activate the system. Most of the time, it is
essential that the system be blocked from an activated mode during
installation of
the device. It is often a pin that blocks the system from activating that must
be
removed after installation is completed. However, it is possible that this pin
may
not be removed after installation for multiple reasons. In that case, the
system will
not activate if counterbalancing spring breaks, and will cause the door to
fall freely.
Therefore, there is a need for a device which assures that the spring break
device
will activate automatically when the counterbalancing spring is wound up, so
as to
have no human interaction required to activate the system so there cannot be
human mistake to cause the system to be left unactivated.
There are several systems that solve the problem of a falling door. But there
are no systems that solve the problem of the alignment of the ratchet system
and/or ensure automatic activation of the spring break device mechanism.
Hence, in light of the aforementioned, there is a need for an improved
braking device which, by virtue of its design and components, would be able to
overcome some of the aforementioned prior art problems.
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Summary of the invention:
The object of the present invention is to provide a spring break device
which, by virtue of its design and components, satisfies some of the above-
mentioned needs and is thus an improvement over other related spring break
devices known in the prior art.
The present invention is particularly advantageous in that it is intended for
immobilizing a cable-operated door, such as garage doors and the like, in the
event of a failure in the counterbalancing system of the door, in order to
impede
free falling of the door thereby preventing serious damages andlor injuries.
In accordance with the present invention, the above object is achieved, as
will be easily understood, with a spring break device such as the one briefly
described herein and such as the one exemplified in the accompanying drawings.
According to yet another aspect of the invention, there is also provided a kit
for assembling the above-mentioned spring break device.
According to another aspect of the invention, there is also provided a driving
(or "counterbalancing") mechanism provided with the above-mentioned spring
break device.
According to yet another aspect of the invention, there is also provided the
garage door provided with the above-mentioned driving (or "counterbalancing")
mechanism.
According to yet another aspect of the invention, there is also provided a
method for preventing a garage door from falling all the way down in the event
of a
failure in its driving (or "counterbalancing") mechanism.
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The objects, advantages and other features of the present invention will
become more apparent upon reading of the following non-restrictive description
of
a preferred embodiment thereof, given for the purpose of exemplification only,
with
reference to the accompanying drawings.
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Brief descriation of the drawings:
Figure 1 is a perspective view of a spring break device cooperating with a
counterbalancing assembly according to a preferred embodiment of the present
invention.
Figure 2 is another perspective view of what is shown in Figure 1.
Figure 3 is a front plan view of what is shown in Figure 2, the spring break
device being shown in an unactivated position.
Figure 4 is another view of what is shown in Figure 3, the spring break
device being now shown in an activated position.
Figure 5 is a fragmentary view of what is shown in Figure 4.
Figure 6 is another view of what is shown in Figure 5, the spring break
device being now shown in an engaged position.
Figure 7 is an exploded view of a portion of what is shown in Figure 2.
Detailed description of a preferred embodiment of the invention:
In the following description, the same numerical references refer to similar
elements. The embodiments shown in the figures are preferred.
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in the context of the present description, the expression "garage door"
includes all types of cable-operated doors and the like. Although the present
invention was primarily designed for a garage door, it may be used with other
kinds of doors, such as slidable truck doors, or with any other items using a
counterbalancing system, as apparent to a person skilled in the art. For this
reason, the expression "garage door" should not be taken as to limit the scope
of
the present invention and includes all other kinds of doors or items with
which the
present invention may be used and could be useful.
Moreover, in the context of the present description, the expressions
"garage" and "door", "torsion spring" and "torsional spring",
"counterbalancing
shaft" and "overhead shaft", "counterbalancing mechanism" and
"counterbalancing
system", as well as any other equivalent expressions and/or compound words
thereof, may be used interchangeably. The same applies for any other mutually
equivalent expressions, such as "spring break device", "braking device" and
"cable
failure device" for example, as apparent to a person skilled in the art.
In addition, although the preferred embodiment of the present invention as
illustrated in the accompanying drawings comprises various components and
although the preferred embodiment of the spring break device and corresponding
parts of the present invention as shown consists of certain geometrical
configurations as explained and illustrated herein, not all of these
components and
geometries are essential to the invention and thus should not be taken in
their
restrictive sense, i.e. should not be taken as to limit the scope of the
present
invention. It is to be understood, as also apparent to a person skilled in the
art, that
other suitable components and cooperations thereinbetween, as well as. other
suitable geometrical configurations may be used for the spring break device
according to the present invention, as will be briefly explained herein and as
can
be easily inferred herefrom, without departing from the scope of the
invention.
Broadly described, the spring break device according to the present
invention, as exemplified in the accompanying drawings, is a spring break
device
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for use with a counterbalancing system of a door, such as a garage door, for
immobilizing the door in the event of a failure in the counterbalancing
system, in
order to impede free falling of the door and thus prevent serious damages
and/or
injuries.
As better shown in the accompanying drawings, the spring break device is
configured for use with the counterbalancing system of the door which, among
other components, typically includes a rotatable overhead shaft operatively
connected to the door (not shown) for operating the same, a plug mounted about
the overhead shaft and being rotatable thereabout, and a torsional spring
operatively connecting the plug to the overhead shaft and being loaded
thereinbetween so as to exert a torsional force capable of counterbalancing
the
weight of the door, the torsional force being transmittable between the
overhead
shaft and the plug via the torsional spring. Counterbalancing systems of
garage
doors are very well known in the art and thus, in the context of the present
description, there is no need to further explain the working principle
thereof, as
apparent to a person skilled in the art.
According to the present invention, the spring break device is used for
blocking rotation of the overhead shaft in the event of a failure of the
counterbalancing system of the door. Indeed, the spring break device according
to
the present invention is used in the garage door industry, and more
particularly, on
a door or an access opening that uses one or more torsion springs for
counterbalancing the weight of the door. As previously mentioned, the breaking
or
failure of a counterbalancing spring results in the free falling of the door
which can
be very undesirable. Consequently, the spring break device according to the
present invention is intended to prevent free falling of the door when such a
counterbalancing spring breaks or fails.
As aforementioned, a garage door needs to have a counterbalancing
system in order to ease the opening and the closing of the door. That
counterbalancing is achieved by one or more torsion springs (1) mounted on the
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main shaft (5) of the door. The torsion spring (1) is fixed on two plugs: on
one side
there is a winding plug (2) that is anchored to the shaft, and on the other
side there
is a stationary plug (3) that is anchored on a bracket (4) that supports the
main
shaft (5) of the door. The present spring break device serves as the said
bracket
(4) on which the stationary plug is anchored. Also, a bearing (6) is inserted
in the
bracket to ease rotation of the main shaft (5), as better shown in Figure 1.
During delivery and installation of the system, the spring break device as in
an unactivated position. This position enable the installer to install the
spring break
device on the door. The automatic activation pin (7) will retain the system in
the
unactivated position. The automatic activation pin (7) prevents the starter
casing
(8) to rotate, thus making possible the lock arm (9) to engage in the ratchet
wheel
(10), as can be easily understood when referring to Figures 2 and 3.
During winding of the counterbalancing torsion spring (1), the automatic
activation pin (7) will slip or break. The automatic activation pin (7) will
not retain
the system in the unactivated position from this moment on. The spring break
device will then be on the activated position, as can be easily understood
when
referring to Figure 4.
During normal operation of the door, the spring break device is at the
activated position. In that position, the stationary plug (3) that is attached
to the
starter casing (8) induces a torque on the device that will retain the starter
casing
(8) in its activated position. The torque generated by the counterbalancing
torsion
spring (1) attached to the stationary plug (3) will always be greater than the
torque
generated by the small torsion spring (11 ) that induces torque to the lock
arm (9).
This starter casing (8) retains or prevents the lock arm (9) from pivoting.
The
ratchet wheel (10) that is screwed on the main shaft (1) is free to rotate
inside the
starter casing (8). The starter casing (8) ensures that the ratchet wheel (10)
is
correctly positioned with respect with the lock arm (9) position, as better
shown in
Figure 5.
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If the counterbalancing torsion spring breaks, the torque created by the
small torsion spring (11 ) that makes the lock arm (9) pivot will become
greater
than the torque of the counterbalancing spring (1). The lock arm (9) will then
be
able to pivot until it reaches the tooth of the ratchet wheel (10). The teeth
of the
ratchet wheel are design in such way that the lock arm (9) can be captured by
the
ratchet wheel but cannot come out. This action will cause the ratchet wheel to
stop
any rotation that would cause falling of the door ("clockwise" direction in
the
figures). On the other hand, the design of the teeth of the ratchet wheel
enable the
raising of the door by a ratchet system ("counterclockwise"), as better shown
in
Figure 6.
The spring break device and corresponding parts are preferably made of
substantially rigid materials, such as metallic materials (steel, etc.),
hardened
polymers, composite materials, andlor the like, so as to ensure a proper
operation
thereof depending on the particular applications for which the spring break
device
is intended and the different parameters in cause (counterbalancing force in
the
spring, weight of the door, etc.), as apparent to a person skilled in the art.
Moreover, it is worth noting that according to the present invention several
mod~cations could be made to the spring break device described and illustrated
herein, without departing from the scope of the present invention, as apparent
to a
person skilled in the art. For example, a) the spring break device can be
installed
on any torsion spring dimensions (diameter) on which a stationary plug can be
installed; b) the automatic activation pin could be made in different material
or
design; andlor c) the alignment of the locking arm and the ratchet wheel can
be
made by different design, as can be easily understood by said person skilled
in the
art.
The present invention is an improvement and presents several advantages
over devices known on the prior art. Indeed, the present invention may be used
in
the garage door industry, with new garage doors or existing garage doors. In
the
case of a failure in the counterbalancing system, the present invention is
devised
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to immediately stop the fall of the garage door and maintain it safely
immobilized
where it is until the necessary inspections and repairs are made. As it is
evident
from reading the above description, the present invention is a security device
used
for immobilizing a cable-operated door, such as garage doors and the Pike, in
the
5 event of a failure of one of the cables operating such cable-operated door
or in the
event of a failure of one of the elements holding the cables (e.g. torsional
spring
breaks, etc.). In such cases, the present invention is devised to impede free
falling
of the cable-operated door and thus prevent significant damages to property
and/or serious injuries. The present invention is a more compact, more
reliable,
10 easier to use, easier to maintain, safer and more cost effective safety
device than
those available in the prior art. Furthermore, the present invention may be
used
with other kinds of doors, such as slidable truck doors, or with any other
items
provided with counterbalancing mechanisms such as the aforementioned, as
apparent to a person skilled in the art.
Of course, numerous modifications could be made to the above-
described embodiments without departing the scope of the invention, as
apparent
to a person skilled in the art.
