CA2477679A1

CA2477679A1 - Spring break device

Info

Publication number: CA2477679A1
Application number: CA002477679A
Authority: CA
Inventors: Michel Beaudoin; Pierre-Louis Foucault; Richard Tremblay; Pascal Provencher; Jean-Francois Levesque
Original assignee: Canimex Inc
Current assignee: Canimex Inc
Priority date: 2004-08-16
Filing date: 2004-08-16
Publication date: 2006-02-16
Also published as: EP1778940A1; EP1778940A4; WO2006017931A1

Description

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

2 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:

3 (CANIMEX) published September 25t", 2003;

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.

4 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.

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.

5 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.

6 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

7 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

8 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.

9 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 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.