The present invention relates to a cost effective, easily operable, and highly adaptable locking system for fire-retardant shutters. In particular, the invention concerns a system for locking a fire shutter or a mechanism that opens or closes a fire shutter, said system comprising at least two movable plates coupled together by means of a magnet, and an actuation member, such as a pawl or a pin.
Fire spreads in a matter of minutes to seconds, generating hazardous fumes that can render people disoriented or even unconscious. Therefore, during fire in a building a quick intervention to ensure the advancing smoke is locked off and the fire progression is delayed provides a key factor in saving lives.
For this and more reasons, there is a constant need for developing faster reacting and more efficient active fire barriers in order to buy as much time as possible for a safe escape of fire victims.
Active barriers are any barriers that move in the event of fire into their fire operational position. Usually, they range from 600°C-sustaining barriers (smoke barriers) to full four-hour to two-hour fire resistance (fire barriers). Traditionally, active fire barriers contain a housing, or a frame, that can be mounted in an architectural opening and a shutter door movable in the housing.
The importance of being able to quickly change between open and closed position of the barrier door accounts for the fact that in most fire shutters the door movement is designed to be light, effortless, and swift. Consequently, without proper locking systems for capturing the shutter door in a desired position inside the housing, the door could be easily moved due to e.g. falling objects or pressures caused by the difference of temperatures on both of sides of the door. For this reason, efficient locking of the shutter door or of the mechanism for moving the shutter door is paramount for the shutter's function as a smoke or fire barrier because any undue leakiness could lead to spreading of toxic fumes and quicker passing of flames.
On the other hand, it is desirable for the locking system to be reversible, i.e. to be reversible to a disengaged state once the locking system is engaged and vice versa. This allows for reusing undamaged shutters following e.g. fire drills or false alarms, and thus has the advantage of being more economical.
The reversibility of locking can be achieved by the use of a magnet or an electromagnet. An example of a mechanism employing a magnet can be found e.g. in
As another example,
Then,
Similarly,
The locking mechanism in the above documents respond to an external trigger generated from outside the shutter. For example, they are triggered by an electrical impulse supplied to the shutter from a power supply station. Such dependence on external triggers makes them more complex to manufacture as well as vulnerable to conditions of power failure during fire.
The present invention addresses this drawback by providing a mechanically simple locking system that is coupled to and movable with an element directly responding to tension (for example of a band or a chain or pressure building in mechanism that actuates closing or opening the shutter as this mechanism operates. As the locking system according to the invention moves in direct response to the pressure or tension arising inside the shutter mechanism, it triggers a change in position of an actuation member that, as a result, becomes engaged (or disengaged) with the same shutter mechanism, preventing it from further movement.
As such, the locking system of the presented-herein invention responds directly to tension or pressure that arises in the shutter-closing or opening mechanism during its operation and therefore it will be triggered even under emergency conditions wherein the shutter is operated manually. Another advantage of the present locking system that by simple modification it can easily be made re-usable through automatic rearming. These and further advantages of the present invention are explained in continuation.
The present invention is defined in the appended independent claims. Preferred embodiments are defined in the dependent claims. In particular, the present invention concerns a system for a belt or chain driven opening and closing mechanism according to claim 1.
In a further aspect, the present invention also provides a fire or smoke shutter comprising a frame, a shutter door, preferably being a rollable shutter door, and a locking system according to the invention.
Finally, the present invention also provides a use of the locking system, as described above, in locking a belt or chain driven shutter opening and closing mechanism.
For a fuller understanding of the nature of the present invention, reference is made to the following detailed description taken in conjunction with the accompanying drawings in which:
As used herein, the term "fire shutter" is to be construed as any active fire- or smoke-retardant barrier comprising a shutter door, e.g. in a form of a roller or a curtain, which in given conditions can open or close for smoke-evacuation purposes or to counteract spreading of fire or smoke. Similarly, the term "fire shutter assembly" or "shutter assembly" is to be understood as referring to a fire shutter in addition to the shutter door also comprising support structure, such as a housing or a frame, for facilitating positioning said shutter in an opening such as an architectural opening or a duct opening.
Further, as used herein the term "mechanism for opening or closing a shutter", "opening and closing mechanism" or in short just "shutter mechanism", is to be understood as any plurality of elements that assist, actuate, or guide the opening or closing of a shutter door mounted in a shutter assembly. Usually, such shutter mechanism will be comprised or mountable in a shutter housing, and can be of any type known in the art of manufacturing fire shutters. Where rolling shutters are concerned, i.e. comprising shutter door in a form of a roll that can wind or unwind around a rotatable mandrel, preferably the shutter mechanism will comprise a band (a band, or a strap) that can wind and unwind simultaneously with the rolling shutter door, potentially serving as a guiding element for said door.
As used herein the term "resilient means" shall be understood as any elastic element or an assembly of elements that can regain its original shape after being bent, compressed, stretched or otherwise extended, e.g. a spring or an elastic band.
Also, as used herein the term "immobilised" will as fixed to support structure such as a wall or a shutter frame.
Lastly, the term "locking system" as used herein is to be construed as an assembly of a plurality of interconnected elements that can respond to a given change and actuate a change of a position or a state of at least one element, further referred to as "actuation member", capable of interacting with either the shutter door, housing, or preferably shutter mechanism, which interaction results in either locking the ability of the shutter door to move or unleashing said ability of a shutter door that was previously prevented from moving due to engagement with said actuation member.
The present invention provides a system for locking a fire shutter via a direct engagement of an actuation member comprised in said system with a corresponding register provided in a shutter door, part of a frame housing said shutter door, or preferably in the mechanism that guides opening or closing of said shutter, further referred to as the opening and closing mechanism. The system according to the invention comprises:
In the system according to present invention, the actuation member (320, 302) together with the first (100) and the second plate (200) are initially held in one position, further referred to as the "initial position", by the tension responsive resilient means (500). In response to sufficient tension or pressure that built up in the shutter mechanism, the two magnetically coupled plates (100 and 200) are moved together with the actuation member (320, 302) to a position other than the initial one, which also results in stretching of the tension responsive resilient means (500). Depending of the set-up of the locking system according to the invention, said movement of the actuation member (320, 302) to a position other than the initial one may result in either engaging or disengaging of said actuation member with respect to a corresponding register within the shutter assembly (i.e. the assembly comprising at least a shutter door, frame housing said shutter door, and the shutter mechanism), that, also depending on the desired set-up, can result in either locking or unlocking the movement of the shutter door.
The shutter mechanism can be of any type known in the art, such as a gear-box or a band-or a chain-based mechanism such as the band-based shutter guiding mechanisms known in rolling shutters. The first plate (100) comprises and interacts with the shutter mechanism, through zone of said plate (100) or an element coupled thereto, further referred to as the tension or pressure actuator (102). The tension or pressure actuator (102) can in turn either be directly connected to the shutter mechanism or can be pressed, pulled, or pushed by said mechanism or an element forming part of said mechanism.
In one preferred embodiment, as schematically shown in
In a preferred embodiment, the opening and closing mechanism is provided as a belt or chain-driven opening and closing mechanism and wherein the tension transmitter comprises:
In an initial state of the embodiment shown in
In a particularly preferred embodiment, the locking system of the invention comprises or is connected to control unit (900) allowing to cancel the magnetic force that holds the first (100) and the second (200) plate together, which allows to separate the second plate (200) from the first plate (100) due to action of the tension responsive resilient means (500). In a situation where the first plate (100) is displaced from the first or initial position to the second position, due to the tension accumulated on the band (405), the cancelling of the magnetic force between the two plates (100 & 200) will enable the previously-stretched tension responsive resilient means (500) to contract to its resting state, thus allowing to pull the second plate (200) away from the first plate (100), and consequently also to return the actuation member (320) to its initial position. This is schematically shown in
In a possible embodiment the magnet is an electromagnet and the control unit (900) allowing controlling of the magnetic force is a source of an electric current that is supplied to said electromagnet. In such arrangement, the electromagnet may be a regular electromagnet, i.e. a temporary magnet powered by electricity in order to maintain its magnetic field; or a reversed electromagnet that comprises a constant magnet that is on when no electric current is generated but can be reversibly demagnetised when an electric current is supplied to it such that the electromagnetic field generated by the flowing electric current cancels out the magnetic field produced by said constant magnet. Different solutions for coupling magnets with source of electricity are broadly known in the art and therefore will not be further discussed herein.
In an alternative embodiment in accordance with the afore-listed embodiments, the target of the electromagnet can be a conventional magnet or another electromagnet. Like this, the cancelling the magnetic force can also be understood as generation of a negative magnetic force (i.e. repulsion between the electromagnet and its target magnet or target electromagnet) that can be obtained by changing the direction of the current in one electromagnet, which results in reversal of the poles of said electromagnet.
In a different embodiment, the control unit (900) allowing controlling of the magnetic force can also be a mechanical element, such as a wedge, capable of engaging between the magnet and its target and separating them physically, thus leading to decoupling of the first and the second plate.
In a highly advantageous embodiment in accordance with any of the previous embodiments, the means providing the force biasing said second plate (200) towards the first plate (100) further comprises a second resilient means (600), further referred to as "arming resilient means (600)", that is coupled to both the first and the second plate (100 & 200) form its opposite ends and acts in support of the magnetic force between the magnet and its target.
The arming resilient means (600) provides a force acting in the same direction as the magnetic force, i.e. acting to bring the magnet and its target together. It should be noted, that the force provided by the arming spring (600) is smaller than the force provided by the tension-responsive spring (500). Consequently, the arming resilient means (600) can act as an arming mechanism for bringing the two plates (100 & 200) together in the situations where they have been disengaged, like for example due to cancelling the magnetic force between the two plates (100 & 200) where the tension responsive resilient means (500) tends to contract and pull the second plate (200) away from the first plate (100). As described supra and shown in panel C in
In line with the above, the combination of the arming spring (600) and selective cancelling of the magnetic force between the plates (100 and 200) provides an advantageous way for controlling engagement status of the actuation member (302). In particular, it provides for such locking control even under the conditions where the shutter mechanism remains under constant pressure or tension.
In the embodiment exemplified in the
In another advantageous embodiment of the present invention, as schematically illustrated in
As can be readily appreciated by any skilled person, the engagement of the actuation member (320, 302) with a cogwheel (403) provides only one possible example of how locking by the system of the invention can be executed. In preferred alternative embodiments of the invention, the actuation member (320, 302) allowing interaction with the opening and closing mechanism is selected from a group comprising:
Locking pins or bolts are well known in the art and were used in locking mechanism of prior art documents such as
A particularly advantageous form for the actuation member of the invention is a pawl that can be engaged with a ratchet coupled to the shutter mechanism. Pawl-ratchet arrangements allow continuous rotary or linear motion in only one direction while preventing motion in the opposite direction, which can be very useful for selectively biasing the direction in which the mechanism of the rolling shutter is desired to be firmly locked. A pawl can be described as any elongated pivotable, often springloaded, extension, whereas a ratchet is usually provided as a round gear or linear rack with teeth spaced such that an end of the pawl can compatibly engage with them. The teeth are uniform but asymmetrical, with each tooth having a moderate slope on one edge and a much steeper slope on the other edge. When the teeth of the ratchet are moving in the unrestricted direction, the pawl easily slides up and over the moderately sloped edges of the teeth, with a resilient means (usually a helical spring) forcing it into the depression between the teeth as it passes the tip of each tooth. However, when the teeth move in the opposite direction, the pawl will catch against the steeply sloped edge of the first tooth it encounters, thereby locking it against the tooth and preventing any further motion in that direction.
Thus, in one preferred embodiment of the present invention, the actuation member (320, 302) is a pawl engageable with a ratchet (403) coupled to the shutter mechanism, as schematically shown in a possible embodiment of the system according to the invention, as shown in
In a preferred embodiment, the actuation member (301, 302) can be further coupled coupled to the first plate (100) by an additional resilient means (700) biasing the actuation member (302) in the direction of the opening and closing mechanism, said additional resilient means (700) being further referred to as the loading resilient means (700). An example of such loading resilient means (700) is schematically shown in
A further advantage of an actuation member (302) that coupled to the second plate (200) by means of an extension (203) that provides said actuation member (302) with a certain degree of movement (e.g. a pivoting or a sliding movement) independent of the movement and/or position of the second plate (200), is that in such arrangement, the exact position of the actuation member (302) can be controlled by additional means other than through manipulation of the force that biases said second plate (200) versus the position of the first plate (100). That is to say that in such embodiments of the invention, the position of the actuation member (302) can be adjustable independently of or even without affecting the position of the coupled thereto second plate (200). Such adjustability could for example be achieved by a provision of a reachable from outside the support structure (400) surface or element which, when moved or pressed by a user, would affect e.g. the shape of the extension (302) so as to retract the actuation member (302) with respect the second plate and possibly relative to its corresponding register (403) in the shutter mechanism. In line with the above, in a preferred embodiment, the extension (203) could comprise a pressing surface (800) which when pressed results in changing of the position of the actuation member (302) relative to the position of the second plate (200). An example of such pressing surface (800), forming part of the extension (203) that couples the actuation member (302) with the second plate (200), is shown in
As also exemplified in
In an alternative embodiment, the extension (203) can be coupled to a motor and operable by means of an electric signal. Thus, in accordance with previous embodiments, that actuation member (302) comprises the extension (203) that can either:
In another preferred embodiment, the present invention provides the locking system according to any of the afore-described embodiments, wherein the support structure (400) is a frame for housing a shutter door. Due to the nature of the invention, naturally such frame will preferably be manufactured of a fire-resistant material, i.e. a material that does not degrade at 300°C for at least 30 minutes, for example inox (stainless steel), aluminium, or various alloys thereof.
In a further aspect, the present invention also provides a shutter assmebly comprising a frame, a rollable shutter door, and a belt or chain driven opening and closing mechanism for operating said rollable shutter door, said fire shutter characterised in that it comprises a locking system according to to any of the afore-described embodiments.
In particular, the present invention provides a shutter assembly comprising:
In another preferred embodiment, a shutter assembly is provided, wherein the opening and closing mechanism comprises a mandrel (402) for rolling said shutter door thereon, whereby the roller shutter is at least partially attached to belt or chain fixed to and rollable on said mandrel and whereby the actuation member of the locking mechanism interacts with said mandrel for locking the opening and closing mechanism.
In another preferred embodiment in line with the above embodiments, the shutter assembly is a fire- or smoke-retardant shutter assembly. Consequently, as it will be appreciated by any skilled person, the shutter mechanism may comprise any of the different arrangements, manual or automated alike, known in the art that are capable of setting a fire-retardant shutter door into motion as to close or open the area defined by the shutter frame. The shutter mechanism can be triggered in response to any an internal or external signal relayed from an initiating device either integrated in the assembly, or nearby, or more distant. Examples of initiating devices are also well known in the art and are not within the scope of the present invention, they include e.g. pull stations, break-glass stations, heat detectors, fusible links, smoke detectors, flame detectors, water-flow detectors, cameras etc.
In a preferred embodiment, the shutter door is a rolling shutter door, i.e. a rollable door coupled to a mandrel and extending by means of rotational motion of said mandrel in the housing. In a particularly preferred embodiment, the shutter mechanism for opening or closing such door comprises a band-based guiding system for guiding at least one lateral edge of said rolling shutter door, preferably both lateral edges during the unwinding of the door. Examples of such guiding systems include guide bands, guide rails, or guiding cables, which advantageously can be coupled to a motor and actively contribute to the opening or closing of the shutter.
Lastly, the present invention also provides a use of the locking system according to any of the above-listed embodiments, in locking an opening and closing mechanism of a shutter, preferably a fire shutter, wherein said mechanism is a belt or chain driven shutter mechanism.
This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.