Patent Application
20060156633
The present invention is directed to sashes formed from injection molded parts, and windows and doors comprising such sashes.
The advantages of polymeric materials for the manufacture of window sashes have long been appreciated. Polymers such as polyvinyl chloride (PVC) have advantages over wood and metal in that they are resistant to rotting and corrosion, while also having relatively good thermal insulating properties and weatherability. Insulating properties of window sashes made of polymeric materials can be further enhanced by incorporating one or more internal air spaces.
A traditional method for manufacturing products from polymeric materials is injection molding, wherein a fluid material is injected into a mold to form the shape of the desired product. The injected material can be a molten thermoplastic that solidifies upon cooling, or a reactive fluid material that solidifies upon undergoing a chemical reaction. While injection molding has the potential advantage of being able to produce parts of high complexity, high dimensional consistency, and low cost, these advantages accrue primarily when large volumes of the same part are produced. This is due in no small part to the cost of producing each mold, particularly molds for large complex parts.
Because the fenestration industry requires the production of a large variety of sizes and styles of window sashes, and because window sashes tend to be large and complex in their configuration, injection molding of sashes requires a large capital investment in molds. This method of production has therefore been less advantageous for this industry than certain other methods. Nevertheless, as exemplified U.S. Pat. Nos. 6,749,797 and 5,189,841, whose contents are incorporated by reference, there have been efforts made in the past to form a window sash and/or a window frame by injection molding.
In one aspect, the present invention is directed to a window sash. The window sash includes first and second sash body members having substantially the same mechanical configuration and engaged to another, with a glazing unit held between the sash body member. Each of the first and second sash body members is a one-piece, injection molded component.
Preferably, each of the first and second sash body members has a inner, facing surface provided with a plurality of locators, the locators on the first sash body member are engaged to the locators on the second sash body member.
In one embodiment, each sash body member is provided with locators of a first type and locators of a second type, the locators of the first and second types being different from one another and complementary to each other. The locators of the first type may each comprise a slot and locators of the second type each comprise a blade. On each sash body, the locators of the first and second types are arranged anti-symmetrically about an axis. The locators of both first and second types may be provided on each of four sides of a four-sided sash body member.
In another embodiment, the locators are all identical. In such case, the locators may comprise holes formed in the facing surface of each sash body member, a plurality of first holes in the first sash body member opposing second holes formed in the second sash body member. A pin may received in each of said opposing first and second holes to help locate one sash body member relative to the other.
In another embodiment, the locators serve the dual function of locating the two sash bodies relative to one another while also linking them to one another. In this embodiment, one locator is a small diameter projection, while the other locator is a larger diameter aperture. A toothed ring, or washer, is provided, wherein the inner and outer peripheries of the washer have projections for engaging the locators. The ring is placed over a smaller, projecting, locator of one of the sash body members, so that the inner peripheral teeth engage the projection, and an aperture locator of the other sash body member is placed over the washer so that the outer peripheral teeth engage the inner surface of the aperture. The engagement of the peripheral teeth with the locators thereby serves to link the two sash body members while also locating them relative to one another.
While locators incorporated internally into the sash body members are useful, sash body members which do not have locators incorporated therein are also contemplated. In the absence of internally incorporated locators, external fixtures can be used to provide suitable location of the two sash body members relative to one another during assembly.
Each of the sash body members may comprise a weldable mating surface. In one embodiment, the weldable mating surfaces comprise a substantially continuous rib.
The assembled window sash may include additional features, such as recesses configured to receive a balancer or a check rail component.
Each sash body member may have a different color, such that one side of the window sash has a different color than the other side of the window sash.
In another aspect, the present invention is directed to a window having one or more such window sashes in a frame. The window may be a single-hung window, or a double-hung window.
In yet another aspect, the present invention is directed to a window sash having first and second sash body members with a glazing unit sandwiched between them. Each of the sash body members has substantially the same mechanical configuration, being originally formed from identical injection molds and then subsequently joined to one another.
In still another aspect, the present invention is directed to a one-piece injection molded window sash body member. The sash body member comprises a inner, facing surface, and a non-facing surface. A first plurality of locators of a first type and a second plurality of locators of a second type are provided on the facing surface, the locators of the first and second types being different from one another, complementary to each other, and arranged anti-symmetrically about an axis of the facing surface. The sash body member is four-sided, with locators of both first and second types provided on each of four sides.
Such sash body members, when joined to form a window sash, are adapted to receive a variety of accessory parts chosen to provide a desired window configuration. Thus, a line of window products using injection molded sash body members may thus be formed. Such a line of window products would then require a reduced number of molds while providing a range of window sash configurations.
Assembly of the sash is performed by placing a sash body member on each side of a glazing unit of suitable size, in mating fashion, with suitable sealants, and attaching the two members together by, for example, hot plate welding, adhesives, mechanical fasteners, or other suitable attachment means. It is preferred that the interface between the two sash body members also be sealed against moisture penetration, although weep holes or other drainage or venting features may be provided. The sealing sash body members can either be performed by the welding process or the adhesive materials, or additional sealing material can be provided.
Constructing the claimed window panels using the system of one-piece sash bodies and optionally selectable accessory parts claimed herein reduces the number of different injection molded sash body members needed for a full line of window panels, while at the same time preserving many of the advantages of injection molding, at a cost less than that normally associated with injection molding of a wide range of different parts.
Hot plate welding can be performed by providing a series of heated bars positioned over the surfaces of the sash members to be welded, heating the surfaces by means of the bars, removing the bars, and pressing the sash members together. The heated bars can have adjustable positioners to accommodate a range of sash member sizes and configurations.
The invention is now described with reference to the attached drawings in which:
Referring to
As best shown in
As used herein, components having the same mechanical configuration are components that can be injection molded from the same mold, so that the same mold can be used to produce both of sash body members 110 and 115, thereby reducing tooling costs. It will be appreciated, however, that parts having substantially the same mechanical configuration can be produced in different colors by changing the color of the polymeric material used. It will also be understood that molded parts having molded-in inserts, as might be used for receiving threaded fasteners, or for structural reinforcement, can also be used, without departing from the one-piece definition.
Referring to
Alternatively, the balancers may be attached to the jambs of the window, rather than to the window sash. When balancers are incorporated into the jambs, suitable members can be installed into longitudinal recesses 131 and 141 to enable the sash to slidably engage the jamb and to enable attachment of suitable couplings, such as a cord, cable, or other like member for operably coupling the balancers to the sash.
Channel 125 is adapted to receive check rail cover 124. Cover 124 can include a locking device 95, shown in
When sash 100 is adapted for use as an upper sash of a double hung window, such as sash 92, shown in
The foregoing sash arrangements are merely illustrative of the range of sash models that can be produced from the single sash body configuration of the present invention. Features of sash body 100, particularly channels 125 and 127, as well as longitudinal recesses 131 and 141 of sash body 100, allow for a great variety of accessory devices to be combined in various ways, using the same sash body members 110 and 115, to produce a range of window sash products greater than would be expected from a single one piece sash member configuration.
Window sash 100 can be assembled by fitting glazing unit 105 onto sash body member 115, with a suitable sealing material 215, deposited as shown in
During assembly, in one embodiment, sash body member 110 can be accurately located relative to sash body member 115 by suitable locators incorporated into the facing sides 150 of the sash body members. Wall 151 can provide a welding surface for attaching sash body members 110 and 115, as well as to provide a barrier to moisture and other environmental contaminants. In another embodiment, in an alternative to locators incorporated into the facing surfaces 150, externally provided fixtures may be used. If such externally applied fixtures are used, reference surfaces marked with arrows or other indicia, and/or other complementary formations, can be provided on the non-facing surfaces of sash body members 110 and 115 to facilitate use of the fixtures. It will be appreciated that while built-in locators are useful, other locating means, such as externally applied fixturing, can also be used.
The type of locators used for locating sash body member 110 relative to sash body member 115 is not particularly limited, provided that the two sash body members are of the same mechanical configuration, so that they can be made from the same mold.
A system of complementary locators can be directly molded into the sash body members, while still allowing both sash body members to be of the same mechanical configuration. Referring to
In
As best seen in
During assembly, the blade-type locator 430 fits between walls 424 and 426, to locate the first sash body member 400 relative to the second sash body member 500 along direction 501. Meanwhile, the blade 437 fits into slot 438, to locate the first sash body member 400 relative to the second sash body member 500 along direction 502, which is substantially perpendicular to direction 501. Sloped receiving surfaces 421 formed on the slot-type locator 402, and the sloped lateral surfaces 431 formed on the blade-type locator 430 guide the two sash body members into position during assembly.
It is understood that locators of the slot-type and blade-type are not limited to the embodiment described hereinabove. For example, a slot-type locator may comprise a plurality of slots, while a blade-type locator may comprise a corresponding plurality of blades. In addition, in other embodiments, locator guide walls may not be provided.
The slot-and-blade configuration described immediately above has the advantage that the various parts have a relatively thin wall thickness. This is an advantage in injection molding, since sink marks and other irregularities on visible surfaces are often caused by large variations in wall thickness, as might be produced by shrinkage of thick ribs or other internal features of injection molded parts during cooling.
It is also useful to mold in structures internal to the window sash for receiving screws and other fastening devices. In one embodiment, these structures are made relatively thin, so as to avoid surface deformities such as sink marks, while still maintaining significant thickness for receiving at least some threaded fasteners. This increased thread receiving thickness is achieved by providing structures in the form of overlapping tabs, with one tab being provided by each sash body member, so that threaded fasteners pass through both tabs, thereby doubling the thickness of material holding the fastener, while allowing the tab in each sash body member to be relatively thin. Alternatively, structures can be molded into the sash body members for holding metal or other threaded devices which can be installed prior to assembly of the sash body. One useful thread receiving fastener is the Tinnerman™ brand clip for receiving a threaded fastener.
In embodiments wherein sash body members are fastened together by welding, it is useful to provide weldable mating surfaces on each sash body member. Referring again to FIG. 4, a weldable mating surface, preferably in the form of weld wall 440 is provided for this purpose. Weld wall 440 preferably is set back from the outer edges of the sash body member 400. In one embodiment, weld wall 440 is a substantially continuous rib, so that the welded seam also acts as a seal to keep moisture out of any cavities formed by the sash body members after assembly. While it is often useful for various parts of the sash to provide moisture barriers, it will be appreciated that suitably located venting may also be useful in some instances, so as to prevent unwanted or harmful pressure buildup, or to provide drainage. Venting can be achieved by providing notches or other discontinuities in weld wall 440, by drilling holes in appropriate locations, or by other venting means, as would be apparent to one skilled in the art.
Welding of sash body members 400 can be performed by heating the edge of each weld wall 440 to an effective welding temperature, and then pressing the two mating weld walls together. Heating of the weld walls can be performed by, for example, hot plate welding. As is known to those skilled in the art, hot plate welding is typically performed by separating the two surfaces to be welded by a short distance, placing a heated plate, or platen, in contact with the two surfaces for a time sufficient to raise the temperature of the weld surfaces to the welding temperature, removing the platen, pressing the heated surfaces together, and allowing them to cool. The heated platen can be made sufficiently large to accommodate a variety of sizes of parts to be welded. It is also useful to provide a non-adhesive coating, such as Teflon™ on heated surfaces that contact the parts to be welded. It has been recognized, however, that conventional hot plate welding may not always be able to accommodate the variety of sizes and shapes of parts that may need to be welded.
The heated bars are then positioned over weld wall 640 by means of positioners 630. Positioners 630 allow movement in two perpendicular directions, using, for example threaded shafts 632 and 634, and drives 635, for moving the bars in directions 650 and 660. Thus, welding apparatus 600 may be able to accommodate a range of sizes of sash bodies to be welded.
Alternative embodiments for positioning the heated bars are also contemplated. In particular, two of the adjacent bars can be fixed, and the sash body members can be positioned relative to these bars, after which the other two heated bars are positioned relative to the sash body members. In other embodiments, the sash body member locating features of the welding apparatus are coupled to the heated bars, so as to determine the location of the heated portions of the sash body members relative to the heated bars. Additionally, apparatus for coupling one heated bar or locating component relative to another, by, for example, rack and pinion linkages for centering a sash body member relative to the welding apparatus, are also contemplated. In addition, while the welding apparatus portrayed hereinabove holds the sash body members in a horizontal orientation during processing, adaptations of the apparatus to allow processing in a vertical orientation, or in an orientation intermediate between vertical and horizontal, are also contemplated.
After positioning the bars, the second of the two sash body members is placed above the bars, and, the upper sash body is then lowered onto the welding bars, which are also lowered onto the lower sash body, so that the welding bars simultaneously contact both surfaces to be welded. This vertical movement can be provided by any suitable lifting apparatus, as would be apparent to one skilled in the art. The sash body members and bars are then held in position for a sufficient time to allow heating of the weld surfaces to the weld temperature, whereupon the upper sash body is lifted a short distance, the bars are lifted and pulled away from the sash body members, using, for example, suitable lifting devises, not shown, and positioners 630. The second sash body member is lowered so that the two sash body members are brought together, and pressed, to form the weld, and thereby create a sash window.
In an alternative embodiment of a welding apparatus 600, the heated bars may be replaced by hollow conduits having a series of holes. The hollow conduits are connected to a hot air source, so that heating of the weld surfaces is achieved by forced air convection.
In an alternative embodiment, a hot plate welding apparatus can be adapted for welding a variety of sizes of sash bodies. Referring to
Referring to
Referring to
Referring to
Alternative embodiments for hot plate welding apparatus are also contemplated. In particular, hot plate 610 can be a separate part from the glazing unit carrier frame 629, so that hot plate 610 can move independently, possibly in a different direction, from the carrier frame 629. In still other embodiments, the hot plate, sash body member placement, and glazing unit placement apparatus are located at fixed work stations, and the components to be assembled and welded are moved from station to station as work progresses. Alternative embodiments also include holding the components to be assembled, as well as the welded sash, in orientations other than horizontal during and after processing.
Referring to
The present invention has been described with respect to specific embodiments. However, it will be appreciated that modifications and variations of the present invention are covered by the above teachings and within the purview of the appended claims without departing from the spirit and intended scope of the invention.
