AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT ORIGINAL Applicant(s): RONALD J LOAR Actual Inventor(s): RONALD J LOAR Address for Service: PATENT ATTORNEY SERVICES 26 Ellingworth Parade Box Hill Victoria 3128 Australia Title: COMBINATION WINDOW SHUTTER FOR FIRE AND SHADE Associated Provisional Applications: No(s).: The following statement is a. full description of this invention, including the best method of performing it known to me/us: 1 COMBINATION WINDOW SHUTTER FOR FIRE AND SHADE Background and Summary of the Invention This application claims benefit of provisional application No. 61/277,257, filed September 21, 2009 in United. States. This invention concerns fire protection, and specifically 5 is directed to a combination window shutter which allows some light to pass through when extended over a window, thus useful as a typical sun or privacy screen, but the shutter or shade being so constructed that when exposed to an exterior fire or firestorm while retracted it will automatically drop, covering the window, 10 and prevent the passing of radiation sufficient to ignite most combustibles or cause the window glass to break. Further, it will protect the window from the impact of flying debris which is often created by a fire storm. Other fire shutters have been constructed of a plurality of 15 elongated slats interconnected together with a plurality of hinges to form a solid screen with virtually no possible passage 1la of light, similar to the standard industrial roll-up door. They are not suitable for use as a sun screen, Further, they tend to be heavy and industrial in appearance. This invention, by allowing some light to pass through the shutter and also being 5 much lighter in construction, can serve the combined purpose of a shade or privacy screen and a fire shutter. The means in which this is accomplished is that the spaces between slats, mesh screen wire, or other elements is sufficiently small so that they block the passage of a significant portion of the radiant waves. 10 Further, the mechanism which automatically closes the shutter during a fire must be able to override manual operation. This can be done by means of a clutch arrangement which is disengaged (released) by a temperature actuated fusible link or other means at a temperature appropriately associated with an exterior fire, 15 such as a wild fire, local vegetation or debris fire, or a close burning building, etc. The mechanism allows the shutter to close automatically (drop, in free fall) by gravity. The key elements are the shutter with limited size openings and the clutch that can be disengaged at an appropriate 20 temperature by fusible links or other means; the former constructed of slats strung on a cable or of mesh screen or other material, essentially fireproof or fire resistant, having openings small enough in at least one dimension to block much of the passage of radiant heat. 2 When used as a sun or privacy screen, the shutter would be raised and lowered manually by conventional means, such as chain lift, crank, gear driven mechanism, electric motor or other. The raising mechanisms and holding ratchets, brackets, drum on which 5 the shutter is wound, tension spring and bearings are all of common design and use, and do not alone form a part of this invention. The details of these components may be modified from those shown to facilitate fabrication, reliability, cost, appearance or for other.reasons. 10 Thus, the present invention provides a combination window shutter and fire protection screen which allows some light to pass through when extended over a window, thus serving as a typical sun or privacy screen, but which is so constructed that it can also automatically function as a barrier to radiant energy 15 and flying debris generated by an exterior fire which might , otherwise ignite combustibles, such as curtains and upholstered furniture just inside the window or break the glass and allow direct flame entrance. The mechanisms are simple and reliable, most having been used countless times in other applications. 20 The uniqueness of this invention is in the nature of the shutter itself, which allows it to perform more than one function in an inexpensive, attractive and practical way, and the mechanism which allows it to be activated automatically during a fire. 25 The above references to and descriptions of prior proposals or products are not intended to be, and are not to be construed as, statements or admissions of common general knowledge in the art in Australia. 3 Description of the Drawings Figure lA is a sectional elevation view of a building with a fire protective window shade of the invention installed at a window. 5 Figure 1B is a perspective view showing the fire protective window shade. Figure 2A is a sectional elevation view showing the window shade on a roll-up drum with the shade partially unrolled. Figure 2B is a detail view in elevational section showing 10 examples of fire protective window shades that can be included in the invention. Figure 3 is a frontal elevation view, partially schematic and partially in section, showing an example of a release mechanism. 15 Figure 4 is a view showing a lever arm with a pressure bearing. Description of Preferred Embodiments Drawing Elements: Figures 1A and 1B: 20 1. Window being protected. 2. Building, exterior face. 3. Combination fire/shade shutter over window - can be mounted on wall or hung from above, and constructed of 4 noncombustible slats or screen (see Figures 2A and 2B for details). 4. Eave hung option. 5. Sill closure piece of noncombustible material 5 (optional). 6. Drum on which shutter is rolled, For mechanism to manually raise and lower shutter and for fusible link(s) and mechanism to automatically lower shutter during a fire, see Figure 3. 10 8. Steel mounting brackets each end of assembly for mounting on building. 9. Sheet metal cover (see Figure 3 for details). 21. Fusible links (a standard commercial product) 22. Stainless steel tension cable with two fusible links 15 (item 21). Figures 2A and 2B: 3. Detail of shutter with articulated slats of metal or other noncombustible material strung on stainless steel cables and. spaced with steel bead spacers or other means. (see items 20 3a). When shutter is down, space between slats shall be small enough to block a significant portion of the radiation, estimated at 1/16", or preferably within range of 1 to 2.5 mm, blocking a significant portion of infrared radiation. It is believed the 5 openings (at least in one dimension) should be on the order of magnitude of the wavelength of infrared radiation typically transmitted in a wild fire or house fire, even though the opening size will usually be greater than that wavelength. In any event, 5 a shutter that is only about 20% open, or even up to 50% or so open, will block a significant portion of the radiation so as to greatly lessen thc radiant heat transferred. The shutter may also be of pierced slats, wire mesh screen or other noncombustible and heat-resistant material in lieu of the solid 10 slats (see items 3b and 3c) 6. Detail of steel drum with shutter attachment. Drum diameter will vary depending on size of window and design considerations (see Figure 3 for details). 7. Weighted bottom edge of shutter to ensure shutter drops 15 by gravity when released by fire-actuated fusible links. 10. Preferably solid steel shaft affixed to brackets each end so shaft does not turn (see Figure 3 for details), 11. Tube shaft over solid shaft and prevented from turning by teeth (item 20) except when released by tension cable with 20 fusible links(see Figure 3 for details). Figure 3: 6. Drum on which shutter is rolled. 8. Steel mounting brackets each end of assembly for 6 mounting on building. 9. Sheet metal cover with 'keeper' to keep lifting chain from coming off cogged wheel/pulley. 10. Solid shaft affixed to brackets to prevent rotation. 5 1-1. Tube shaft over solid shaft and prevented from turning by teeth (item 20) except when released by tension cable/fusible links to move axially left and disengage. 12. Drum bearings at each end of drum. 13. Tension spring to counterbalance weight of shutter 10 during manual use, as in a roll-up window shade. 14. Cogged wheel/pulley for lifting chain when raising or lowering shutter manually. 15. Chain to operate shade. 16. Ratchet teeth and stops for holding shutter at desired 15 height similar ; to mechanism used for pull-down window shade). 17. Bearing disk connected to portion of tube shaft acting as thrust bearing; tube shaft can rotate when released by tension cable with fusible links. 18. Lever arm connected to tension cable at one end and 20 having pressure disk 18a at other end, 19. Bracket with pin for bearing plate pivot. 20. Teeth to keep tube shaft (item 11) from turning except when released by tension cable and fusible links. 'l 21. Fusible links (a standard commercial product) which melt and release tension cable 22 at appropriate temperature within range of about 200* to 500 0 F. 22. Stainless steel tension cable with two fusible links. 5 Description of Operation: The illustrated assembly is one example of how the invention can be carried out. In this example, the tension cable 22 holds the lever arm 18 in a position such that the bottom of the lever arm as seen in Figure 3 is held to the right and the bearing disk 10 or thrust bearing 17 is held to the left by the pressure disk 18a, in the position shown in the drawing. This keeps the teeth 20 of the tube shaft 11 engaged and thus the tube shaft 11. fixed against rotation. In the event of a fire adjacent to the building, producing sufficient heat to raise the temperature of 15 either or both of the fusible links 21 to a preset triggering temperatures, the cable 22 will no longer hold the bearing disk 17 and the tube shaft 11 in place with the teeth 20 engaged as shown in Figure 3. The tube shaft 11, normally fixed in place and relative to which the drum 6 rotates when the shade is raised or 20 lowered, is permitted axial movement to the right and frees itself from the teeth 20 due to the inclined surfaces of the teeth as shown and becomes freely rotatable, so the entire drum can rotate freely along with the tube shaft 11. In this way the 9 shade's torsion roll-up spring 13 does not come into play and the shade can unroll in a free fall by gravity, especially with the weighted bottom edge 7 assisting in unrolling of the shade. Note that other types of rotation brakes than the teeth arrangement 5 illustrated could be used, such as a simple friction brake with a friction pad against a plate. A spring can be included (not shown) urging the shaft 11 toward disengagement from the rotation brake. If the chain pull 15 is included, this will simply rotate 10 freely as well. Note that with the pull-down shade mechanism as illustrated, including the torsion spring 13 and the ratchet teeth 16 (as in a conventional window shade), such a chain pull 15 is not necessary, but a simple handle or chain could be included at the bottom edge of the shade if desired. The torsion 15 spring can effect the raising of the shade when this is initiated by an operator, as in a typical window shade. Other releasable retaining devices and mechanisms for releasing the shade are possible, and the invention is not limited to the fusible link and bearing disk arrangement shown.. 20 For example, a fusible link could consist of a pin between an inner shaft such as the tube shaft 11 which is normally held fixed, and any other fixed structure. In that way, the fusible link pin would be subjected to heat and would break, and the tube shaft 11 could then freely rotate on the inner, solid shaft 10, 9 so that the drum releases the shade by gravity. In another form of the shade without a torsion spring 13, but with a mechanical chain such as shown at 15 to both raise and lower the shade, the chain 15 or the pulley 14 would be latched in some way when the 5 shade is in the retracted, raised position. .A fusible link could be located between the drum 6, at the left end of the drum as seen in Figure 3, and the pulley 14, thus normally linking the drum to the pulley 14. The fusible link would be exposed to the heat of a fire, and would be caused to fail by the heat of the 10 fire, releasing the drum 6 from the shade raising mechanism, i.e. from the pulley 14. Other arrangements involving fusible links, heat-responsive or alarm-activated electric solenoid, etc. are also possible and within the scope of the invention. The terms drum and roller as used herein are to be broadly 1$ interpreted, not necessarily requiring a hollow drum. Further, , the term shade is to be understood as meaning shade or shutter. Also, the term window is to include a glass door or a door that includes glass. The above described preferred embodim-ents are intended to 20 illustrate the principles of the invention, but not to limit its scope. Other embodiments and variations to these preferred embodiments will be apparent to those skilled in the art and may be made without departing from the spirit and scope of the invention as defined in the following claims. When used in this specification and claims, the tens "Comprises" and 25 'comprising" and variations thereof mean that the specified features, steps or integers are included. The tcrms are not to be interpreted to exclude the presence of other features, steps or components. 10