1. Field of the Invention
The present invention generally relates to window assemblies for motor vehicles, and more particularly, to plastic window assemblies for motor vehicles.
2. Description of the Related Technology
Over the past several decades, automobile manufacturers have sought to improve automobiles in every way. From improving safety, to enhancing functionality, to lowering costs, they have made great strides. One area of great concern, especially recently, is the rising cost of gasoline. In the past few years alone, gasoline has reached record high prices in the United States. One way the industry is trying to combat the problem is by developing alternative fuel technologies. However, developing alternative fuel technologies involves barriers to entry, such as lack of infrastructure and available fuel sources. Another way the industry is addressing the problem of high gas prices is by attempting to introduce gasoline powered automobiles that are more fuel efficient. This has been accomplished to some extent by introducing more efficient drive trains, but there are limitations to this approach. Other attempts have been made to reduce vehicle weight. However, in the past, it was generally believed that reducing the weight of a vehicle compromised the safety of the vehicle.
Windows in automobiles have typically been constructed of glass. Automotive glass has many limitations due to the constraints inherent with the material. More specifically, automotive glass is constrained by the need to include complex attachment and regulating systems. These systems add considerable weight to a door module, which is in addition to the weight of the glass itself. The additional weight of glass window assemblies impacts the performance of a car or truck by increasing fuel consumption and/or raising the center of gravity of the vehicle. Glass windows may also be undesirable because of their propensity to shatter, and because they may need to be shattered in an emergency situation to create an escape route.
The present invention provides a plastic window assembly for a motor vehicle that adds less complexity and less extra weight to a motor vehicle, as compared to a glass window assembly. Further, the present invention improves the safety of a motor vehicle, even though the present invention causes a motor vehicle to weigh less than a similar motor vehicle having a glass window assembly.
The plastic window assembly generally includes a plastic window panel and motor. The motor is coupled to a gear that operates to move the plastic window panel between opened and closed positions.
In one aspect, the plastic window panel of the plastic window assembly has at least one gear track to define a gear path.
In another aspect, the plastic window assembly includes a frame having portions forming a pair of intersecting, non-planar tracks.
In yet another aspect, the plastic window assembly includes a flexible strip, having a first end and a second end, one end of which is connected to the gear and another end of which is connected to the plastic window panel.
These and other aspects and advantages of the present invention will become apparent upon reading the following detailed description of the invention in combination with the accompanying drawings.
Referring now to
Each worm gear train 28 comprises a worm 32 in meshing engagement with a worm wheel 34. The worms 32 are mounted to the shafts 26 so as to be rotationally driven thereby. The shafts 26 may be a single shaft extending through the motor 24 or it may be two shafts 26, with one shaft 26 extending from each side of the motor 24. Each worm wheel 34 preferably has supporting structure (not shown) to prevent translational movement of each worm wheel 34.
Preferably, the plastic panel 22 is made of polycarbonate, which has a high impact strength and excellent transparency. However, other suitable materials may include, by way of example, polymethylmethacrylate (PMMA), acrylic, polyacrylate, polyester, polysulfone, or copolymers, and combinations thereof. It is also contemplated that the plastic panel 22 could be formed of other thermoplastic resins, or any other suitable material. The plastic panel 22 may include bisphenol-A polycarbonate and other polycarbonate resin grades (such as branched or substituted) as well as being copolymerized or blended with other polymers, thereby, forming a blend with Acrylonitrile Butadiene Styrene (PC/ABS blend), or a polyester (PC/POLYESTER blend). The plastic panel 22 is most preferably transparent, and less preferably translucent. The plastic panel 22 may further comprise various additives, such as colorants, mold release agents, antioxidants, and ultraviolet absorbers.
The plastic panel 22 may also include various protective or functional layers located on the surface of the plastic panel 22. The protective or functional layers may include one or more of a weathering layer, a conductive layer, a decorative layer, and an abrasion resistant layer. Theses layers may be provided on either or both sides of the plastic panel 22, and more than one of the same type of layer can be included on the same side of the plastic panel 22. For example, there could be multiple weathering layers for enhanced protection from the sun and other elements. By way of example, the weathering layer may include a film comprising polycarbonate, PMMA, a combination of polycarbonate and PMMA, polysiloxane, polyurethane, polyurethane acrylate, or any other suitable material. Further, the weathering layer may include a coating of a material such as acrylic, polyurethane, siloxane, or a combination of these types of materials to provide a high weatherability, including long term ultraviolet (UV) protection. Further, silicone nano-particles may be blended into the weathering layer or a siloxane co-polymer may be formed into the material making up the weathering layer by polymerization, which may help promote adhesion between the weathering layer and adjacent layers. The weathering layer may also include UV absorbing molecules, such as, by way of example, one or more of or a combination of inorganic oxides, benzophenones, benzoylresorcinols, cyanoacrylates, triazines, oxanilides, and benzotriazoles. Preferably, the weathering layer has a thickness between 10 and 1250 micrometers. The weathering layer may be as described in U.S. Pat. No. 6,797,384, which is hereby incorporated by reference in its entirety.
The conductive layer could be provided as a resistive layer or grid, to serve as a heater, defroster, defogger, or an antenna, by way of example. The conductive layer may be formed of a printed resistive ink or a transparent conductive layer, for example, applied to the plastic panel 22 or one of the other layers.
The decorative layer could add any desired decoration to the plastic panel 22. For example, the decorative layer could be a decorative printed ink or a blackened border to conceal fit and finish imperfections.
The abrasion resistant layer may include a single layer or multiple sub-layers. The abrasion resistant layer may be comprised of aluminum oxide, barium fluoride, boron nitride, hafnium oxide, lanthanum fluoride, magnesium fluoride, magnesium oxide, scandium oxide, silicon monoxide, silicon dioxide, silicon nitride, silicon oxy-nitride, silicon oxy-carbide, hydrogenated silicon oxy-carbide, silicon carbide, tantalum oxide, titanium oxide, tin oxide, indium tin oxide, yttrium oxide, zinc oxide, zinc selenide, zinc sulfide, zirconium oxide, zirconium titanate, or a mixture or blend thereof. Preferably, the abrasion resistant layer is comprised of a composition of SiOx or SiOxCyHz depending upon the amount of carbon and hydrogen atoms that remain in the deposited layer. In this regard, the abrasion resistant layer resembles a “glass-like” coating. The abrasion resistant layer may also comprise UV absorbing molecules, such as, but not limited to, inorganic oxides, benzophenones, benzoylresorcinols, cyanoacrylates, triazines, oxanilides, and benzotriazoles.
The various layers may be applied by any technique known to those skilled in the art. Such techniques include, by way of illustration and not limitation, coating techniques (sol gel, spray, flow, dip, and curtain), film insert molding techniques, printing techniques (screen printing, membrane image transfer, pad printing), and deposition techniques (plasma-enhanced chemical vapor deposition (PECVD), expanding thermal plasma PECVD, plasma polymerization, photochemical vapor deposition, ion beam deposition, ion plating deposition, cathodic arc deposition, sputtering, evaporation, hollow-cathode activated deposition, magnetron activated deposition, activated reactive evaporation, thermal chemical vapor deposition).
The plastic panel 22 has gear tracks 36 located on the two opposing side edges of the plastic panel 22 to define the gear path for each worm wheel 34. The gear tracks 36 are preferably formed directly in the plastic panel 22, for example, by being molded into the plastic panel 22. In the alternative, the gear tracks 36 could be formed separately from the plastic panel 22 and attached to the plastic panel 22. In the latter case, the gear tracks 36 could be formed of a material other than plastic, such as metal. In either construction, the gear tracks 36 form gear teeth that mesh with the worm wheels 34.
The motor 24 is operable to alternatively rotate the shafts 26 in opposing rotational directions. Because the worms 32 are fixed to the shafts 26, they rotate when the shafts 26 rotate. Rotation of the worms 32 causes the worm wheels 34, which are meshed therewith, to also rotate. The worm wheels 34 are further meshed with the gear tracks 36 such that rotation of the worm wheels 34 causes the plastic panel to be displaced in a translational direction. In the present embodiment, the worm wheels 34 and the grooved tracks 36 form rack and pinion gear sets, wherein the rotational motion of the worm wheels 34 is converted to linear motion of the plastic panel 22. Since the motor 24 is capable of rotating the shafts 26 and worms 32 in opposite rotational directions, the worm wheels 34 also are capable of moving in opposite rotational directions. Thus, the worm wheels 34 may move the plastic panel 22 in a first linear direction and a second linear direction. For example, if the plastic panel 22 is installed as a side window in an automobile, the plastic panel 22 will be moved in upward and downward directions, and if the plastic panel 22 is installed as a sun roof, the plastic panel 22 will be moved in forward and rearward directions.
Although the plastic panel 22 is illustrated having gear tracks 36 on two opposite sides of the plastic panel 22, it should be understood that a gear track 36 could be located on merely one side of the plastic panel 22, with one corresponding worm gear train 28. In another embodiment, a single gear track 36 could be provided on a central portion or extension of the plastic panel 22. In such an embodiment, the plastic panel 22 would preferably have extra length to accommodate the length of the gear track 36 without exposing any of the gear track 36 in a visible portion of the plastic panel 22 when the plastic panel 22 is in the closed position.
In another embodiment, the gear tracks 36 could be formed into a shape other than the simple gear teeth as shown. For example, the worm wheels 34 could be thin disc-shaped gears, which would allow the gear tracks 36 to take on other configurations or constructions, such as a plurality of indented squares or the like. Likewise, if the gear tracks 36 were provided on a front surface, as opposed to a side surface, of the plastic panel 22, then still other embodiments of the gear tracks 36 are possible, without falling beyond the spirit and scope of the present invention.
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The motor 124 is operable to drive the gear 132 so as to move the plastic panel 122 between an extended and a retracted position. More specifically, the motor 124 is operable to rotate the gear 132 in opposing rotational directions. When the gear 132 is rotated in a first rotational direction, the flexible strip 136 is wound, or rolled up, around the gear 132 and pulls or moves the panel 122 to its retracted position. When the gear 132 is rotated in the opposing rotational direction, the flexible strip 136 is unwound from the gear 132 and the plastic panel 122 is pushed in a second direction (opposite to the first direction) which moves the plastic panel 122 to its extended position.
Extending from the lateral side edges of the plastic panel 122 are a plurality of projections or guide pins. As shown, two guide pins 146, 147 extend from a first side 153 of the plastic panel 122, and two additional guide pins 148, 149 extend from the opposite side 155 of the plastic panel 122. The pins 146, 147, 148, 149 are received within and guide the plastic panel 122 along tracks 150 of a window frame 152, which is described in further detail below. The pins 146, 147, 148, 149 are preferably formed of polycarbonate and unitarily formed with the plastic panel 122. In the alternative, the pins 146, 147, 148, 149 may be formed separately from the plastic panel 122 and/or they may be formed of a different material from the plastic panel 122. For example, the pins 146, 147, 148, 149 may be formed of metal if desired, or they may be formed of black plastic with a black frame of the plastic panel 122 and attached to the plastic panel 122.
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In this embodiment, the plastic panel 222 has guide pins (not shown) extending from only one side of the plastic panel 222. The frame 252 has a corresponding set of tracks 250, including a central section 256, a terminal section 254, and an intermediate section 258. The window assembly 220 operates similarly to the window assembly 120 of
Weight reduction, in addition to replacing glass with polycarbonate, is achieved by being able to utilize a lighter regulator system. Both worm gear trains 28 and direct motor drives 24, 124 are light weight, are compact in size, and can be directly coupled to the plastic window. The guide pins and other features may be molded directly into the plastic panel 22, 122, 222. Thus, the design of the present window assembly 20, 120, 220 reduces overall complexity of the window and door module.
As a person skilled in the art will readily appreciate, the above description is meant only as illustrative implementation of the principles this invention. This description is not intended to limit the scope or application of this invention in that the invention is susceptible to modification, variation and change, without departing from the spirit of this invention.
This application claims the benefit of U.S. Provisional Application Ser. No. 60/862,281 filed on Oct. 20, 2006, entitled “POLYCARBONATE GLAZING FOR MODULAR DOORS,” the entire contents of which are incorporated herein by reference.
Number | Date | Country | |
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60862281 | Oct 2006 | US |