Patent Application
20090272037
The invention relates to window structures, and in particular concerns a building exterior window assembly having jalousie slats or louvers configured for thermal insulation and sun shading. The slats lap one another when closed and can be spaced from a window pane or sash so as to confine an air space.
A building window typically comprises a rectangular frame, often constructed from extruded lengths of metal or polymer or another material. The frame is arranged in an opening in a building wall having a given depth or wall thickness, and the frame carries a glass unit. In some windows, the glass is stationary and seals the opening. Advantageously, however, the glass unit can comprise a fixed pane and an overlapping movable sash pane, or two slidably overlapping sashes, one or more hinged casements, pocket panels or another movable structure by which the window is opened or shut selectively, namely by adjusting the position of its movable parts relative to the frame.
Windows have several useful aspects. These include, at least, admitting or blocking light and viewing, admitting or blocking air circulation, thermal insulation (conductive, convective and/or radiant) when closed, capacity to block rain or other precipitation or dampness, security against unauthorized entry or exit, etc. A window may be more or less effective for these particular functions due to the specific structure chosen. There are tradeoffs.
Windows also have important aesthetic effects. The size and character of an exterior window can vary the perceptions of those in a room in a building and those who view the window from the exterior. From the interior, for example, different sizes and structural arrangements can carry different impressions with respect to privacy and security versus public exposure, warmth in a cold climate or comfortable coolness in a hot climate. From the exterior, windows vary from welcoming expansive openings to forbidding security arrangements.
Among possible window structures, the jalousie type window comprises a plurality of slats or louvers that are mounted on parallel spaced pivot axes. Some examples of jalousie structures with louver mounting and pivoting mechanisms are disclosed in U.S. Pat. Nos. 6,061,962 and 5,907,926. These patents are incorporated by reference in this disclosure.
Typically the pivot axes of the slats are horizontal but they can be vertical instead. The slats are ganged by a linkage mechanism causing the slats to pivot open or closed in unison. Jalousies can have security benefits because the spacing between the slats is typically too small to admit an intruder in any pivot position of the slats. The slats can be pivoted into a position at least partly perpendicular to the plane of the building wall. When fully perpendicular, planar slats occupy the minimum cross sectional area obstructing air flow or view. Wholly planar parallel slat structures might be sized and spaced so as to pivot into a common plane when closed. Often the slats are configured to overlap at their edges when closed. In order to seal closed against the passage of air, the edges of the slats can have seals and/or can be shaped with stepped edges that are complementary to the shape of an adjacent slat. Slats may comprise sheet material that is flat, or curved across a lateral cross section. A curve tends to contribute stiffness. Slats may have that vary in thickness across a lateral cross section in a diamond or lozenge or other shape. These variations from a thin flat planar slat shape increase the apparent slat thickness when the slats are fully open.
The jalousie slats can comprise clear glass, colored or translucent glass, or an opaque material such as sheet metal, wood or plastic, or painted or covered glass. Clear glass is desirable for viewing when opened or closed. Opacity is desirable for privacy when closed. A sheet metal material provides security.
Among other possible variations, the slats of a jalousie window can be relatively wider or narrower in a lateral direction perpendicular to the slat pivot axis, and might be centered and balanced on the pivot axis or off-center so as to cantilever when open. A smaller number of wider slats can encompass the same size window opening as a greater number of narrower slats, regardless of the relative placement of the pivot axis. But when the slats are opened, different arrangements produce different effects, for example as to sun shading, slat position and span of displacement of the slat edges in a direction perpendicular to the plane of the window, etc.
In a situation where there is a temperature difference between opposite sides of a window structure (indoors versus outdoors), the glass portion of the window and the supporting frame conduct heat energy; the glass passes radiant heat; and any unsealed openings permit convection. Heat may be conducted from the warm interior of a room to cooler air outside; or, heat from a warm exterior of a building may be conducted into an air conditioned or other room that is desired to be maintained at a temperature cooler than the exterior air. On the other hand, even when there is a temperature difference, it may be desirable (or undesirable) in some instances not only that some heat energy is transmitted, but to encourage energy transfer in one direction or the other. An example is to admit sunshine through the window of a heated space on a cold day. What is needed is an optimal way to control the open and closed and light and heat transmission aspects of a window structure.
Design choices made to maximize the openness of window structures for view and air circulation, when desired, are generally inconsistent with the choices that might be made to minimize heat loss and drafts, and to provide high security. There are a number of window design and construction techniques that are used in an effort to maximize both the desirable open and closed aspects of window. These include, without limitation, storm windows with superimposed exterior panes or protective panels, double-pane glass windows, inert gas captured between sealed spaced panes, overhangs and awnings, shutters, interior shades, Venetian blinds, curtains, and similar arrangements.
It would be desirable to provide a thermally insulating window assembly capable of controlling the passage of heat energy, possibly in the case of a large temperature difference across the window, exterior storms and similar challenges. Doing so would be helpful in maintaining a comfortable and stable interior temperature in the building. Energy costs are another consideration, and the cost associated with energy required to compensate for the heat conduction through a window should be factored into consideration of the total cost of the window.
It would therefore be desirable to provide a thermally insulative window apparatus that provides the openness of a window for some purposes while providing securely closed and/or energy conservation aspects for other purpose, and does so in a structure that is aesthetically pleasing and not unduly expensive.
To address these and other needs, and in view of its purposes, the invention provides, according to one aspect, a window assembly comprising a window attached to a window frame carrying a jalousie configuration comprising a plurality of slats formed of a thermally insulating and/or security material that are pivotable to open or closed positions and when closed provide a barrier the thermal energy.
The slats can comprise a thermal insulation material. Additionally, in certain embodiments the slats are mounted to close substantially in a plane that is spaced from a glass window pane, sash or other window panel, thereby confining an air space when the jalousie slats and the window panel are closed. Pivoting of the jalousie slats, and optional opening and closing of the window panel, provide a range of possible open and closed states for the window assembly, wherein more or less air and light, and consequently more or less heat energy, can pass between indoor and outdoor spaces.
The window assembly can be opened for purposes of relatively unobstructed view and for admission of light, air and sunshine. The window assembly likewise can be closed, preferably considering a range of orientations of the jalousie slats, and in a preferred embodiment including opening or closing of an inside sash or casement with at least one glass pane. The states of closure that are permitted include limited operation of the slats as sunshades while permitting view through the window opening with the pane open or closed. The jalousie and/or window pane both preferably are capable of being manipulated, for admitting or blocking light and sunshine, for permitting or blocking air flow, for battening down as security against intrusion or severe storms, and for isolating a captured thermally insulating air space between a window pane and exterior jalousie slats.
In one embodiment, the insulative window assembly comprises a jalousie structure having slats made to include a thermal insulation material. The slats can be integrally molded of insulating material such as substantially rigid molded foam, or molded onto or otherwise affixed to an axle structure such as a metal tube with a square cross section that couples at non-round fittings to pivoting mechanisms in the window frame at one or both ends of each slat. Alternatively, the slats can comprise a hollow envelope such as plastic or sheet metal, with thermal insulation provided as a filling. The slats can be opaque for sun shading or translucent to admit light.
In another embodiment, the invention provides an insulative window assembly comprising a window attached to a window frame, the window comprising at least one and preferably two panes, at least one of which is movable with respect to the window frame, for example as slidably lapping sashes, and an insulative jalousie attached to the window frame. The jalousie comprises a plurality of parallel slats comprising foam insulation disposed within an aluminum casing. Each of the window and the insulative jalousie is surrounded by the window frame and situated between the indoor and outdoor surfaces of a building wall when the insulative jalousie is in a closed position. In respective embodiments, the closed jalousie slats can be substantially flush with the outer surface of the building wall when closed, and can be pivoted at an axis adjacent to a lateral edge of the slot so as to cantilever the slat outwardly when opened, serving as a sunshade. This arrangement is considered particularly apt for warm climates wherein one object is to keep the indoor area cool.
A number of additional aspects and embodiments will be made apparent in the following description of a range of nonlimiting examples and considerations according to which the preferred arrangements can be varied within the scope of the invention claimed.
The invention is best understood from the following detailed description when read in conjunction with the accompanying drawing. It is emphasized that, according to common practice, the various features of the drawing are not necessarily to scale. On the contrary, the dimensions of the various features are arbitrarily expanded or reduced for clarity. Like numerals denote like features throughout the specification and drawing.
Window apparatus 2 as shown defines a jalousie configuration and comprises parallel slats 4 carried on horizontal axes so as to pivot at journals at opposite sides of window frame 8, although other slat arrangements and orientations may be used as will be discussed with respect to other exemplary embodiments. Slats 4 include opposed longitudinal edges 6 and although the insulative jalousie is formed of five slats 4 in the illustrated embodiment of
The rotation axes of the depicted slats 4 are generally horizontal, i.e., parallel to the ground (not shown), i.e., the longitudinal axes of slats 4 extend left to right in the illustrated embodiment of
Each slat 4 is advantageously pivotally coupled to window frame 8 via a drive mechanism disposed in one or both opposite members of the frame. The drive mechanism for moving the slats can be substantially as disclosed in U.S. Pat. Nos. 6,061,962 and 5,907,926, which are incorporated by reference in this disclosure. In general, the slats in those disclosures are attached via non-round fittings to a rotatable element in the frame having an eccentric crank arm. The crank arms of all the slats are coupled in a parallelogram linkage to a mechanism such as a geared rotatable handle. Operating the handle lifts or lowers an element coupled with respect to one of crank arms in the linkage. Thus, operating the handle causes the linkage to rotate all the slats clockwise or counterclockwise on their axes to close or open the jalousie as shown in
The linkage can rotate the slats open from the rotational position shown in
Each slat 4 is preferably thin and flat. The slats can be arranged to admit light when closed, e.g., comprising thermally insulated clear or translucent spaced glass panes, spaced from one another and sealed together around their edges. According to an aspect of the invention, the slats are structured to be thermally insulative, e.g., made of a thermally insulative material that might alternatively be opaque. Accordingly, the slats form a thermal barrier when closed.
The invention can be applied to a window wherein the insulative jalousie slats provide the only obstruction to airflow (i.e., the window opening need not have a separate glass pane or shutter or window screen apart from the jalousie). However, according to an alternative embodiment, the insulative jalousie slats can be provided in association with a glass pane or other barrier that provides an independent closure of the window opening to supplement the jalousie slats. In that case, the slats are spaced on the outdoor side from a panel comprising, for example, one or more glass panes. When the insulative jalousie slats are closed, a thermally insulated closed airspace is bounded by the slats, the glass panel and the frame.
Depth 12 may be more or less as shown by the various exemplary embodiments. According to one embodiment, the slats can occupy a plane flush with the frame and with the outdoor side of the wall of the building in which the window is mounted. In that case, the depth 12 can be such as to place the opposite (indoor) side of the frame flush with the inner side of the wall. It is also possible to arrange either the indoor or outdoor side to protrude beyond the building wall. Increasing depth 12 while also increasing the lateral dimension of the slats, increases the extent to which the slats form sun-shading structures that are effective when the sun is high in the sky. Also, placing the slat pivot axes nearer to the upper lateral edge of the slats versus the lower lateral edge, cantilevers the slats into a sun-shading arrangement (e.g., see
According to an advantageous embodiment, depth 12 may be slightly less than the depth of the wall within which insulative window apparatus 2 is installed. In the embodiments shown, the plane occupied by the slats when closed is near the outdoor edges of the frame and the window panes or panes 16 is at or adjacent to the indoor edges of the frame. (Although it should be appreciated that the invention is applicable to situations other than exterior windows.) These relative positions are shown in further detail in
In the illustrated embodiments, the frame of the window is permanently fixed in the window opening, i.e., nailed or otherwise fasted to studs or other structures that frame the window. It is also possible to embody the invention such that the frame in which the jalousie slates are carried is an inner frame and is removably affixed in the window opening, for example being attached by hinges to an outer frame that is permanently mounted in the opening (not shown in the drawings).
It is possible to install the insulative window assembly as shown such that the respective slats face into the room and the window 14 portion faces outside, or vice versa. However, in order most effectively to exploit the sunshade aspects of the jalousie slats, it is preferable to place the glass on the inside and the slats on the outside. This arrangement also enables manual access to open and close the window panes, whereas panes that are beyond the jalousie slats would require a mechanism such as a casement operator with handle on the indoor side of the frame.
Referring to
In one embodiment, casing 30 comprises a sheet metal such as aluminum or another metal or alloy. Casing 30 may be clad with or formed entirely of a polymer. Various alternative polymers, blown or solid or fibrous, fibrous mineral material such as fiberglass, and other thermally insulative materials are suitable. In one exemplary embodiment, filler material 32 comprises a foam insulation injected and set in situ.
In various exemplary embodiments, thermally insulative filler material 32 may be natural or manufactured, particular or solid or foamed or fibrous. Some examples are materials comprising one of cotton, fiberglass, silicon aerogel, carbon aerogel, polystyrene, polyicynene, polyurethane, polyisocyanurate, rockwool, slagwool, cork, hemp, straw and wool, or combination thereof.
In general, a higher insulating value is better than a lower one, subject to materials expense and the expected environment (e.g., expected temperature difference across the thermal boundaries). For example, the thermally insulating material of filter material 32 may have an insulating value of R-5 or greater. (Units of R-value may be expressed as Kelvin square meters per watt (K·m2/W)).
When the slats are closed, such as illustrated in
In embodiments employing a window pane as a supplemental barrier independent of the jalousie, the window pane 16 of window 14 may be fixed immovably in the frame 8 or may slide within a track 40 as in the illustrated embodiment. The track may be arranged for lateral or vertical displacement. A window screen (not shown) can be provided to block insects. Other known mechanical and functional arrangements associated with windows can be used in addition to the elements described.
Referring to
In yet another embodiment, each slat 4 may be generally flat with opposed surfaces that curve toward each other and converge to form a tip at longitudinal edges 6. According to this exemplary embodiment, the thickness of slat 4 tapers near longitudinal edges 6 and respective longitudinal edges 6 of adjacent slats 4 may overlap when slats 4 are in closed position. Another possibility is a squared “S” shape in cross section where the upper edge of each lower slate hooks with the lower edge of the next upper slat and so on. The last slats similarly engage with the frame members. A jalousie arrangement with durable materials and such mechanical engagements between the slats is useful to provide protection against air borne debris in severe storms.
The preceding examples illustrate the principles of the invention. It will thus be appreciated that those skilled in the art will be able to devise various arrangements which, although not explicitly described or shown herein, embody the principles of the invention and are included within its spirit and scope.
The examples and associated conditional language found in this disclosure are for instruction in understanding the principles of the invention and demonstrate general and specific methods, structures and concepts that differ from the art. However, the invention should be construed in accordance with the appended claims and not limited to the embodiments disclosed as examples. Statements reciting principles, aspects, and embodiments of the invention the specific examples thereof, encompass structural and functional equivalents, including currently known equivalents and equivalents that may yet be developed to similarly perform the same function, regardless of structure.
In discussing the embodiments shown in the drawings and other examples, this description uses various relative terms such as “lower,” “upper,” “horizontal,” “vertical,” “above,” “below,” “up,” “down,” “top”and “bottom” as well as derivatives thereof (e.g., “horizontally,” “upwardly,” etc.). These terms should be construed to refer to the orientation as then described or as shown in the drawing under discussion, and do not imply that the invention is necessary limited to a similar orientation or relative arrangement of parts. Similarly, terms concerning attachments, coupling and the like, such as “coupled”, “connected” and “interconnected,” refer to a relationship wherein structures are secured or attached to one another either directly or indirectly through intervening structures, as well as both movable or rigid attachments or relationships, unless otherwise apparent from the disclosure and context.
The appended claims defining the invention should be construed broadly to include other variants and embodiments of the invention, which may be made by those skilled in the art without departing from the scope and range of equivalents of the invention as disclosed.
