Ventilation – Having inlet airway – Including specific air distributor
Reexamination Certificate
2000-01-24
2001-11-13
Joyce, Harold (Department: 3744)
Ventilation
Having inlet airway
Including specific air distributor
C454S313000
Reexamination Certificate
active
06315657
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an air inlet grille having airflow director blades (louvers) and more particularly to novel indexing means for controlling the position of those louvers.
2. Description of the Prior Art
Air distribution devices have long been available, which are characterized by adjustable louvers. These differ among themselves as to (i) the means for directionally adjusting the louvers and/or (ii) the manner for temporarily retaining one or more of the louvers in a selected directional orientation.
Louver directional adjustment is typically accomplished by rotating the louver on an axis parallel to the long dimension of the louver. Louvers typically have one pivot point at each end and are retained at this pivot point in the grille frame. Typical methods for providing the pivot point for a louver include a portion of the louver extending through a hole in the frame, or a screw or other fastener means driven through a hole in the frame and into the louver.
Louvers may be adjusted individually, or by acting on two or more louvers at once (“gang operated” louvers). Individually adjustable louvers have the potential advantage of more precise air flow control, since each louver can be adjusted to its optimal position. On the other hand, gang operated louvers can be more convenient to adjust, as the one adjustment controls several or all of the louvers in a grille. Often, gang operated louvers are worked by a linkage which can be accessed more conveniently than could the louvers individually.
Known air distribution devices typically retain the louvers in a selected position by means of frictional engagement and/or an indexing device.
The most common method for retaining louvers is with friction. Relatively smooth surfaces are in contact and resist sliding, owing to the coefficient of friction and clamping forces between the two parts. Examples of this kind include the use of wire against a round louver end pivot (U.S. Pat. No. 2,991,707 Goettl); a flat spring-loaded surface pressing against a parallel flat planar surface of a louver (U.S. Pat. No. 3,180,246 Johnson); a spring-loaded screw end pressing against a cylinder attached to the end of a louver (U.S. Pat. No. 2,236,865 Bailey et al); or a spring-loaded expandable round pivot point on the grille fitted into a hole on the frame (U.S. Pat. No. 3,270,657 Jaye). Since grilles are typically manufactured from materials that are hard and smooth (e.g. metal or plastic) they inherently have a low coefficient of friction. Louvers retained in a set direction only by the resistance of sliding friction between two components may not be capable of withstanding forces that unintentionally cause the louver to rotate into an undesired orientation.
The second method for retaining louvers in a given position employs an indexing device. The sliding surfaces between the rotating louver and a fixed point on the grille (for example, the frame) are provided with geometric features which are intended to increase the resistance to adjustment of the louver direction from certain selected positions.
One typical method of louver indexing uses a wire spring pressing against a square or rectangular section of the louver end. The square or rectangular section of the louver end is approximately at the pivot point around which the louver rotates. As it does so, the louver will naturally rest in a position where the spring rests flat against one side of the square or rectangular section of the louver as exemplified in U.S. Pat. No. 2,759,410 (Hurt, Jr.). In this arrangement, however, if a louver is adjusted away from its resting point it may unexpectedly adjust back to the resting point when vibrated, thus limiting the range of reliable settings for the louver.
A second indexing method employs a leg integral to the louver, acting as spring as the louver is rotated across undulations in the frame as illustrated, for example, in U.S. Pat. Nos. 5,338,252 (Bowler et al.) and 5,626,517 (Kil). Such an arrangement requires the louver material to be capable of acting resiliently, so limiting the choice of materials from which the louvers may be fabricated.
It is a principal object of the present invention to provide a new louver indexing device for grilles which exhibits a high degree of reliability and reproducibility of the indexing function.
It is a further object of the invention to provide indexing means giving distinct tactile feedback to a person adjusting a louver to any of a selected number of discrete angular positions.
It is a further object of the invention to provide indexing means which resists accidental louver repositioning by reason of vibration, airflow force or other loads.
It is a still further object of the invention to provide louver indexing means which may be used with louvers fabricated from a wide range of structural materials.
SUMMARY OF THE INVENTION
With a view to achieving the aforementioned objects and overcoming the disadvantages of the prior art, the present invention provides a novel louver indexing device for grilles in which an indexing plate is a resilient separate component from either of the louver of the frame, allowing for a wide choice of materials for the louver, frame and indexing plate.
An air outlet grille according to the present invention comprises a rectangular housing of frame members, a series of parallel louver blades pivotably connected at opposite ends to the frame members by screw means and resilient indexing means. Preferably, this comprises a spring plate with angularly disposed arcuate projections that engage with a rear projection on the louver blade itself. The projections are configured so that the rest positions of the louver blade are at 0, 15, 30 or 45° from parallel with the air flow.
A screw or other fastener connects the louver, frame and indexing plate. By keeping the louver in contact with the indexing plate using a fastener, small variations in the louver length and/or frame straightness become acceptable, contributing to more economical manufacture and more reliable operation of the louver indexing device, because frame straightness is not as critical as in prior art arrangements, less rigid frames can be employed for more economical manufacture, or longer frames (unless larger grilles) can be produced which still have reliable louver indexing.
REFERENCES:
patent: 2236865 (1941-04-01), Bailey et al.
patent: 2254258 (1941-09-01), Perkins
patent: 2759410 (1956-08-01), Hurt, Jr.
patent: 2991707 (1961-07-01), Goettl
patent: 3012494 (1961-12-01), Drummond
patent: 3176603 (1965-04-01), O'Day, et al.
patent: 3180246 (1965-04-01), Johnson
patent: 3270657 (1966-09-01), Jaye
patent: 3735691 (1973-05-01), Gofton et al.
patent: 3786738 (1974-01-01), Fahre
patent: 3996845 (1976-12-01), Harris
patent: 4545294 (1985-10-01), Dayus
patent: 5338252 (1994-08-01), Bowler et al.
patent: 5470276 (1995-11-01), Burnell et al.
patent: 5586933 (1996-12-01), Sawyer et al.
patent: 5626517 (1997-05-01), Kil
patent: 5788570 (1998-08-01), Cho
patent: 61-83839-A (1986-04-01), None
E. H. Price Limited
Joyce Harold
Ridout & Maybee
LandOfFree
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