Window lift mechanism
A dual rack and pinion system is provided for a window lift mechanism. The window lift mechanism includes improved window brackets for simple mounting to a window. A modular frame design is provided to improve assembly of the window lift mechanism into the door of a vehicle. An improved assembly method is provided for the dual rack and pinion system. The system is also provided with a smart motor and incorporates resilient shock absorbers in the dual rack and pinion gear train to allow more time for the smart motor to detect and react to an obstruction in the window. The window lift mechanism includes a support bracket mounted to the window and a motor supported on a support bracket, wherein the support bracket permits axial and rotational movement of the window relative to the support bracket.
This application claims the benefit of U.S. patent application Ser. No. 10/400,820 filed Mar. 27, 2003. The disclosure of the above application is incorporated herein by reference.
FIELD OF THE INVENTIONThe present invention relates generally to an apparatus for moving a window into an open or closed position. In particular, the present invention relates to a mechanism for use with an automobile window, wherein the mechanism utilizes an improved dual rack and pinion assembly and method of manufacturing. The mechanism further utilizes pinion gears with resilient shock absorbers to cushion the system from disturbances, a clutch mechanism to prevent back-drive of the worm gear and a support bracket that allows the window to find the path of least resistance during closure.
BACKGROUND OF THE INVENTIONModern automobiles typically include a window lift assembly for raising and lowering windows in the door of the vehicle. A common type of window lift assembly incorporates a “scissor mechanism” or a drum and cable mechanism. A scissor-type system utilizes a series of linkages in a scissor configuration such that as the bottom linkages move apart, the top linkages do as well, resulting in a scissor-like motion. The window is fastened to a bracket connected to a linkage. A motor and gearset drives the scissor mechanism in power operated window mechanisms.
The scissor-type and drum and cable mechanisms are typically mechanically inefficient, prohibiting the use of light-weight materials and requiring the use of relatively large motors to drive the system. The large motors necessarily require increased space and electrical power and also increase the weight of the system. With the limited space in a scissor-type or drum and cable system it is also necessary, in order to provide the required torque transfer efficiency and acceptable up and down times (3-4 seconds), to have a small diameter pinion gear, typically 0.5 to 0.75 inches, and relatively large worm gear, typically 1.8 to 2.5 inches in diameter, with gear ratios of 9 to 16 and 80 to 90, respectively. This results in excessive worm gear speed in the range of 3000 to 4000 RPM which causes excessive worm gear tooth shock and armature noise. The combination of high torque, typically 80 to 125 inch-pounds at stall, and shock due to high worm speeds mandates that either expensive multiple gears and/or single worm gears with integral shock absorbers be utilized.
Further, the scissor-type mechanism does not take into account the manufacturing deviations in the door, specifically with the window frame and mounting points, and deviations in the manufacture of the scissor-type mechanism. Deviations in the door and scissor-type mechanism result in larger than necessary forces being applied to the window when it cycles up and down. The larger force on the window causes undesirable noise in the passenger cabin.
Accordingly, a need exists for a window lift mechanism with increased efficiency that would allow for a reduction in the motor size and hence the mass of the system, and a support structure for the window that permits the window to find the path of least resistance when it cycles up and down.
SUMMARY OF THE INVENTIONThe present invention provides a window lift mechanism that utilizes a dual rack and pinion drive mechanism that includes a motorized input from a worm shaft that drives a worm gear drivingly connected to one of the pinions of the dual rack and pinion system. A motor with the worm driveshaft and the pinions are supported by a base which traverses the dual rack structure when the dual pinions are driven. According to one aspect of the present invention, the window lift mechanism has two support structures each including a window bracket coupled to the window. The window brackets each include a channel for receiving the window therein. A pair of metal plates are disposed on opposite sides of the window bracket and include a clamping mechanism engaging each of the pair of metal plates for drawing the metal plates toward one another.
There is an interface between the first and second supports which permits axial and rotational movement of the window with respect to the second support. Specifically, the first support has a forked side coupled to the window and a slot for receipt of a protrusion from the second support. The allowed movement of the window allows the closure member to find the path of least resistance during closure, and aids in overcoming manufacturing imperfections.
According to an alternative embodiment of the present invention, the window brackets are each provided with a wedge mechanism received in the channel for securing the closure member in the channel.
According to another aspect of the present invention, a method for assembling a window lift mechanism is provided including mounting a motor to a base, the motor including a worm drive shaft and worm gear meshingly engaged therewith. The method includes loading pinion gears into the base by placing the pinion gear onto a drive shaft connected to the worm gear and mounting the second pinion gear in the base. A dual rack assembly is then placed in alignment with the pinion gears and power is applied to the motor to drive the pinion gears to engage the pinion gears with the rack.
According to still another aspect of the present invention, the dual rack assembly is made as a modular unit including a base or frame structure which is adapted to be mounted to the door of the vehicle. The pair of rack members each including a plurality of gear teeth extending along the rack members are formed either as a molded unitary piece with the base structure, or are snap fit or otherwise fastened to the base structure for defining the modular unit.
According to yet another aspect of the present invention, the dual rack and pinion assembly is provided with a smart motor capable of detecting unusual forces applied to the window while being closed and capable of either shutting off or reversing drive of the motor. The system is further provided with one or more resilient shock absorbers operably engaged between the worm gear and pinion gears in order to allow the drive motor to have more time to react to unusual forces applied to the window.
The window lift mechanism of the present invention has a gear set with at least one pinion gear and at least one worm gear operatively coupled together and supported by the window. The gear set is driven by a motor with an output shaft having a worm which engages the worm gear. The window lift mechanism utilizes a clutch mechanism to increase the efficiency of the torque transfer from the motor to the worm gear in the gear set. The clutch mechanism includes a pair of springs located within the worm gear. This clutch mechanism prevents back drive, hence allowing for the worm on the output shaft of the motor to have a lead angle greater than seven degrees. With a larger worm angle, the amount of torque transferred from the worm to the worm gear is increased, allowing for a smaller motor. The smaller motor reduces the mass of the system.
Further, the gear set in the window lift mechanism of the present invention has a resilient shock absorber operatively engaged between the pinion gear and the worm gear. The shock absorber has surfaces with notched portions to allow for deformation of the resilient shock absorber, which reduces unwanted stress in the gear set and thereby increases the life of the gears.
BRIEF DESCRIPTION OF THE DRAWINGSThe present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.
Referring generally to
The support structure 16 includes a main bracket 24. According to a first embodiment, a pair of guide brackets 26 (best shown in
The window brackets 42 have a window channel 44 for receipt of the window 14 and a guide channel 46 having a semi-cylindrical inner surface for receiving the semi-cylindrical guide portion 38 of the guide bracket 26, as best shown in
As shown in
With reference with
During assembly, the window 14 is inserted in the channel 72 and the wedge member 80 is inserted next to the window 14 and sidewall 78 of the channel 72. The cross-bar 92 of toggle spring member 84 is then pulled downward from the position shown in
With reference to
Referring to
With reference to
As illustrated in
As an alternative to molding the dual rack system 150 integrally with the frame 160, the dual rack system 150 can also be provided with snap-fit engagement for connection to the frame 160 by including snap insert members 168 as illustrated in the cross-section of
A recent development in power window regulators are referred to as smart regulators, i.e., to have the capability of going up and down fast by touching the switch once. Due to automotive regulations, it is mandatory that on the way up, that from 4 inches to 0.1 inch from the top, the window must be capable of stopping and reversing prior to generating a force in excess of 100 Newtons. To achieve this, manufacturers have utilized sophisticated electronics and memory chips so that the window knows where it is at all times based on past or previous experience. In this way, if the window senses an object in its path, it will know that it is abnormal and hence, reverse. Essentially, detection methods are put in place by using memory chips employed within a controller 174, as illustrated in
With reference to
With regard to the construction of the worm gear 142 and drive pinion gear 126, it is noted that each of these gears is constructed similar to second gear portion 128B of the slave pinion gear 128. In particular, each of these gears include radially inwardly extending fingers, such as fingers 194, which engage an elastomeric shock absorber such as shock absorber 182 illustrated in
When a shock absorber system is utilized in combination with a smart motor system and the upward moving window is obstructed and generates an impulse determined by force multiplied by time (Fxt) the shock absorbers increase the time factor, hence reducing the applied force at any point in time. With reference to
With reference to
The clutch springs 218 each include a helically wrapped spring wire having two end fingers 226 extending radially inward. The end fingers 226 of each clutch spring 218 are disposed opposite one another. The clutch springs 218 are received within the annular body portion 220 of the spring retainer 216 and are arranged at 90 degree offsets from one another in order to define four separate quadrants 236, 238, 240, 242 (best shown in
With reference to
A shock absorber bridge 246 is provided with a disk shaped body portion 248 having a pair of axially extending semi-cylindrical fingers 250. The semi-cylindrical fingers 250 extend into the clutch housing 228 and are received in opposing quadrants 238, 242 defined by the end fingers 226 of clutch springs 218. The shock absorber bridge 246 also includes a cylindrical protrusion 252 extending from a second side of the disk shaped body 248 and includes three radially extending triangular protrusions 254 extending from the cylindrical protrusion 252. The cylindrical protrusion 252 and triangular protrusions 254 of shock absorber bridge 246 are received within an interior cavity 256 of pinion gear 204. As best shown in
The resilient shock absorber 262 is pressed into the cavity 256 of the pinion gear 204 so that the inwardly extending protrusions 258 of the pinion gear 204 are received in the radially inwardly extending cutouts 264 of the resilient shock absorber 262. The cylindrical protrusion 252 and radially extending protrusions 254 are inserted in the central opening of the resilient shock absorber 262 and the radially extending cutouts 266, respectively. The resilient shock absorber 262 is provided with a plurality of body sections 268 which are each disposed between a radially inwardly extending cutout 264 and a radially outwardly extending cutout 266.
Due to the limited space in the cavity 256, the side surfaces and radial surface of the body sections 268 are notched inwardly to accommodate for deformation. Specifically, elastomeric materials have a Poisson's ratio of approximately 0.5, and therefore, under compression and/or tension, the volume of the material is retained. Hence, inward deformation in one direction causes the material to bulge outward in other directions. Thus, compression of the resilient shock absorber 262 in the lateral direction will cause the elastomeric material to deform or bulge outward in the axial and radial directions. Thus, in order to accommodate for the bulging of the elastomeric material under compression, the notched surfaces 270, 272 allow room for deformed elastomeric material to move into. If the notches were not provided, non-optimum force deflection occurs since the efficiency of the resilient shock absorber 262 is directly related to the amount of deflection at any applied force. Thus, a preferred design is one which allows the volume to be maintained. As shown in
During operation, the motor 60 drives driveshaft 138 and worm 140 which in turn rotates the worm gear 202. The worm gear 202 has the internal shaft portion 212 of gear hub portion 208 fixedly attached thereto for rotation therewith. As the shaft portion 212 rotates, force is transmitted through clutch springs 218 via engagement of the end fingers 226 engaging with the radially extending semi-cylindrical protrusions 214. The end fingers 226 thereby transmit rotation to the shock absorber bridge 246 via axially extending fingers 250. The shock absorber bridge 246 then transmits rotation to the pinion gear 204 via the resilient shock absorber 262. The resilient shock absorber 262 absorbs forces that are applied through the drive system 18 in order to prevent damage to components of the drive system 18, the support structure 16, or window 14.
Worm 140 is helical and directly engages the teeth of the first worm gear 202. The lead angle of the worm 140, according to a preferred embodiment of the present invention, is greater than seven degrees. Typically, a worm lead angle in such a system is required to be less than or equal to seven degrees, as a necessity in order to prevent backdrive. However, in these systems, the efficiency of the torque transferred from the worm to the worm gear tends to be low due to the low lead angle of the worm. In systems with low efficiency, a larger motor is needed to create more torque to overcome the inefficiencies in the system. In the present invention, however, the clutch mechanism in the form of clutch springs 218 is provided in order to allow the lead angle of the worm 140 to be increased greater than seven degrees in order to improve the efficiency thereof while the clutch mechanism prevents system backdrive. By increasing the lead angle of the worm 140, the efficiency of the torque transferred from the worm 140 to the worm gear 202 is increased, hence allowing for the use of a smaller motor 60.
The system of the present invention provides an improved, more efficient window lift mechanism wherein variations in the door and lift mechanism are accommodated for by the two degrees of freedom allowed for by the guide bracket and window bracket interface. In addition, the clutch mechanism, which is housed within the interior space of the worm gear 202 allows for the lead angle of the worm gear 202 to be increased for improved efficiency while preventing undesirable back drive from occurring with the increased lead angle utilized on the worm. Finally, the improved resilient shock absorber 262 being provided with notched surfaces to allow for displacement of the resilient material when loaded under compression, also leads to a more efficient shock absorber. The worm gear/pinion assembly is also provided with a compact arrangement since the worm gear and pinion can be disposed side by a side with a majority of the clutch structure and shock absorber structure being maintained within the interior compartments defined by the worm gear 202 and pinion gear 204.
With reference to
As illustrated in
With reference to
After the first and second pinion gears 356, 358 are assembled, a dual rack 360 (illustrated in
With the disclosed support bracket 300, the assembly of the window lift mechanism is greatly simplified by eliminating the need to mount the transmission housing to the cross bar portion as a separate unit. Thus, the reduction of the number of parts by combining the transmission housing and cross bars also reduce the number of fasteners required to mount the transmission housing to the cross bar portion. The reduction in the number of assembly steps therefore corresponds to a reduction in assembly costs associated with the dual rack and pinion window lift mechanism. The combining of the transmission housing and cross bar into a single mold also reduces the number of separate molds and separate molded articles that need to be made. Thus, there is a significant reduction in capital expenditure for reducing the number of molds necessary for molding the component parts of the dual rack and pinion system. By combining the cross bar portion and transmission housing portions, a reduction in the total amount of raw material required is achieved, therefore, reducing the weight and cost of the system. Finally, because all of the mounting structure such as bore 326 for supporting the shaft 350 and slave gear hub portion 324 are molded into a single component, the consistent reproducibility of parts and consistent assembly is achieved.
Previously, in designing rack and pinion power regulators for any particular door model, the angle of the B and A-pillars on the front and rear doors, the radius of curvature of the window, the length of the window travel, and the distance of the safety bar inner surface from the outside surface of the glass were considered. Using these criteria, the racks of prior dual rack and pinion systems have been specifically designed to be angled to match the angle of the B-pillar while the support rack was specifically designed to be generally horizontal relative to the angled rack for supporting the horizontal bottom edge of a window pane. Furthermore, the radius of curvature of the rack was designed to specifically match the radius of curvature of the window as well as the length of the racks being provided to specifically match the distance of travel of the window panel.
Previously, as the guide angles between the moving cross bar and rack has needed to match the A and B-pillar angles and as the radius of curvature of the rack match the radius of curvature of the window, it was necessary that a new and separate set of cross bar molds and rack molds be built for each and every door design. For convenience and economic reasons, the rack and cross bar molds are typically built with a right and left hand cavity so that from a single injection shot, individual parts are obtained for the driver side and the passenger side regulators. An additional set of molds would, of course, have to be built for the rear doors on a four-door vehicle. A complete set of molds for a four-door vehicle typically costs approximately $400 thousand and has the capability of generating approximately 1.5 million regulator part sets per year in a 24-hour, six-day work week. Additionally, an automated testing and assembly line which attaches gears to the cross bar and the cross bar to the rack and tests the full up and down travel of the system costs approximately $300 thousand, and can also handle approximately 1.5 million regulators per year in a 24-hour, six-day work week. Those assembly lines are somewhat universal, and may be used to accommodate different vehicle regulators. Therefore, typically for a four-door vehicle, a capital outlay of approximately $700 thousand is required to accommodate molding, assembly, and pre-shipment testing of component parts.
For costing purposes, the capital expenditure is typically amortized over the life of the product. Car models generally sell less than three-quarters of a million units annually, therefore, dedicated molds are greatly under utilized and consequently the amortization associated with each regulator produced is higher than it needs to be if there was a way to fully utilize each set of molds built; i.e., if the same mold set could be used for different car models and/or if the same mold set could be used for front and rear doors.
As illustrated in
According to an alternative design, as illustrated in
Changing the shape; i.e., the angle at the bottom of the glass, and/or matching respective bracket lengths to achieve the desired result allows for the universality in relation to the B-pillar design element criteria. With regard to the design criteria element relating to the variations in the radii of window curvature from one model window to the next, it is noted that these variations may be conveniently satisfied by taking advantage of the controlled flexibility naturally built into the plastic flexible rack designs, and by utilizing the back and forth freedom of motion inherently built into the design of the dual action brackets such as illustrated in
With regard to the design criteria element addressing the glass travel distance, variances in glass travel may be conveniently provided for by using incremental inserts 514, 516, 518, 520 within a universal rack mold so that different rack lengths may be obtained from a single mold cavity. As illustrated in
The value of using the combined solutions to provide for a universal dual rack and pinion power window regulator is substantial. Typically, car models average sales of 175 thousand units per year with the range varying from 50 thousand to 350 thousand. Table 1 below illustrates the influence of using these novel concepts on regulator amortization rates for an example case. For convenience, and in line with actual practice, a typical car model life is assumed to be seven years. Taking the average of 175 thousand sale units per year for a four-door vehicle; i.e., 750 thousand regulators total per year, then if a rack model is built to accommodate front and rear windows in the same vehicle, then just one more vehicle model at the same average annual volume will fully utilize a dual cavity rack mold. Therefore, in real life, molds would be carefully selected and mixed and matched to car models that are relatively close to one another in terms of the critical parameters of pillar angle, radius of curvature, and travel length. In summary then, by adopting and combining the solutions to the design elements of B-pillar angle, radii of curvature and length of travel to provide for a universal power window regulator, substantial savings occur in design time, capitalization costs, inventory, amortization costs, manufacturing convenience, and most importantly the improved overall simplicity of the total system.
The estimated capital expenditures and associated amortization costs for case A example, assuming two four-door vehicles with average yearly volumes of 175 thousand automobiles, seven year model lines, mold set cost for the front units, $260 thousand, mold set cost for the rear units $260 thousand, assembly line cost $300 thousand with yearly mold set, and assembly line capacity of 1.5 million units.
From the above table, it is seen that the amortization cost is approximately 13.6 cents per unit utilizing dedicated molds, while the amortization cost is approximately 5.7 cents per unit for window regulators utilizing universal molds so that a total difference is obtained of approximately 7.9 cents per unit. Furthermore, the total up front investment is reduced by $780 thousand.
Estimated capital expenditures and associated amortization costs for case B example, assuming three four-door vehicles with average yearly volumes of 50 thousand, 100 thousand, and 200 thousand units, respectively. The Case B also assumes seven year model lines with mold set cost for the front units being $260 thousand, rear units being $260 thousand, and assembly line cost of $300 thousand with the yearly mold set and assembly line capacity of 1.5 million units, the same as in Case A.
From the results illustrated in Table 2, the amortization cost using dedicated molds is 17.4 cents per unit while the amortization cost for using universal mold is 5.7 cents per unit providing a total savings of 11.7 cents per unit. Furthermore, the total up front capital investment is reduced by $1.3 million.
Another aspect of the present application centers around further entrancement of the greaseless nature of dual rack or pinion power window regulators. Old fashioned arm and sector and cable driver systems have numerous exposed components, both metal and plastic, which need to be greased to assist various sliding motors and to ensure quiet operation. The application of grease, either manually and/or automatically, to those components is costly and time consuming. Additionally, it generates a host of unwanted behaviors, namely:
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- (a) wearing away of grease over time which causes poorer, noisy performance as time progresses;
- (b) non-equivalent performance at varying temperatures resulting in varying window travel time as temperature varies from ambient, to +180° F., and to −40° F. At −40, the grease tends to solidify and not function as a lubricant, while at high temperature, the grease becomes free-flowing and falls through gravity to the lowest areas, finally dripping off the units;
- (c) grease has a tendency to absorb dust and crud so that after time it does not function as a lubricant but rather, as an abrasive causing excessive wear and, hence, looseness at critical locations;
- (d) grease parts are difficult to handle during installation, requiring gloves and have the potential of increased dropped parts and surrounding body surface contamination.
The dual rack and pinion regulators discussed here, and as previously exemplified in the referenced patents, eliminate the unwanted behavior associated with old fashioned regulators by judiciously using an internally lubricated thermoplastic for the various component parts. From a lubrication vantage point, these parts function perfectly but have the unwanted behavior associated with all plastic components, namely, they inherently have the tendency to statically charge locally due to sliding or rubbing surface motion. These statically charged surfaces have a profound tendency to attract dust which potentially can cause surface pitting and, hence, less than optimal behavior as time progresses. This tendency to locally statically charge and remain charged may be readily eliminated by molding the various plastic components from a statically dissipative internally lubricated thermoplastic. To be statically dissipative, a molded surface resistivity must be less than 10−7 ohm/cm2 and preferably less than 10−5 ohm/cm2. This static dissipative character may be judiciously built-in to the base thermoplastic into a composite by the addition of various additives, namely, carbon black, graphite, metal powders, metal flakes, conductive polymers, and compounds and/or a combination of the above with selected fillers like mica, etc. Improved cost/performance may be achieved by matching the internal lubricant with a static dissipative additive which also has lubrication character; e.g., dispersive carbon black and/or graphite.
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- The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.
Claims
1-15. (canceled)
16. A method for assembling a window lift mechanism, comprising the steps of:
- mounting a motor housing assembly to a main bracket, said motor housing assembly including a motor drivingly connected to a worm and worm gear, said worm gear including a shaft rotatably connected to said worm gear and extending through said main bracket;
- mounting a first pinion gear onto said shaft and mounting a second pinion gear in meshing engagement with said first pinion gear;
- placing a dual rack system in alignment with said pinion gears; and
- applying power to the motor to drive said pinion gears to engage said pinion gears with said dual rack system.
17. The method of claim 16, wherein said step of applying power to the motor further includes driving the first and second pinion gears to move the main bracket and motor to a predetermined position for convenient door installation.
18. The method of claim 16, wherein said step of placing a dual rack system in alignment with said pinion gears includes placing the dual rack assembly in a guide system of said main bracket.
19. (canceled)
20. An integrally formed dual rack system, comprising:
- a pair of elongated parallel racks each including a plurality of gear teeth extending there along; and
- a cross brace structure extending between said pair of elongated parallel racks and integrally molded as a unitary piece with said pair of elongated racks.
21. A window lift mechanism comprising:
- a dual rack system;
- a support structure supported on said dual rack system;
- a drive pinion gear supported by said support structure and in engagement with a rack of said dual rack system;
- a slave pinion gear supported by said support structure, said slave pinion gear including a first gear segment in engagement with said drive pinion gear and a second gear segment in engagement with a second rack of said dual rack system, said first and second gear segments including a resilient shock absorber operatively engaged there between;
- a worm gear supported for rotation by said support structure and operatively joined with said drive pinion gear; and
- a motor supported by said support structure and including an output shaft having a worm engaged with said worm gear.
22. The window lift mechanism according to claim 21, further comprising at least one resilient shock absorber operatively engaged between said drive pinion gear and said worm gear.
23. The window life mechanism according to claim 21, further comprising a pair of resilient shock absorbers operatively engaged between said drive pinion gear and said worm gear.
24. The window lift mechanism according to claim 21, wherein said motor is a smart motor system capable of detecting obstructions and reversing operation thereof in response to a detected obstruction.
25. A window lift mechanism comprising:
- a dual rack system;
- a support structure supported on said dual rack system;
- a gear train including: a drive pinion gear supported by said support structure and in engagement with a rack of said dual rack system; a slave pinion gear supported by said support structure in engagement with said drive pinion gear and a second rack of said dual rack system; a worm gear supported for rotation by said support structure and operatively joined with said drive pinion gear, said gear train including a plurality of resilient shock absorbers disposed therein; and
- a motor supported by said support structure and including an output shaft having a worm engaged with said worm gear.
26-39. (canceled)
40. A closure assembly comprising:
- a closure member;
- a pair of first supports each coupled to said closure member;
- a pair of second supports each coupled to a respective one of said pair of first supports, said pair of second supports being disposed at a fixed distance from one another and adapted to be driven for the raising and lowering of said closure member; and
- an interface between said pair of first supports and said pair of second supports each adapted to accommodate both axial and pivotal movement of said closure member with respect to said pair of second supports.
41. The closure member of claim 40 wherein said pair of first supports each have a slotted end for receiving said closure member and a semi-cylindrical recess for receiving a semi-cylindrical head of said pair of second supports.
42. The closure member of claim 40, wherein said interface includes a head portion slidably and rotatably received in a channel portion.
43. The closure member of claim 42, wherein said head portion is semi-cylindrical and said channel portion is semi-cylindrical.
44-63. (canceled)
Type: Application
Filed: Mar 26, 2004
Publication Date: Jun 7, 2007
Inventor: Paul Fenelon (Nashville, TN)
Application Number: 10/550,766
International Classification: E05F 15/16 (20060101);