Flexible or portable closure – partition – or panel – Plural strip – slat – or panel type – With mounting or supporting means
Reexamination Certificate
2001-06-06
2002-10-29
Johnson, Blair M. (Department: 3634)
Flexible or portable closure, partition, or panel
Plural strip, slat, or panel type
With mounting or supporting means
C160S199000, C160S118000
Reexamination Certificate
active
06470952
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to powered, automated door systems, and more particularly to a laterally symmetrical, bi-folding door assembly having four folding panels comprising a jamb panel and a generally central panel to each side of the center of the door opening. The jamb panels are each approximately one sixth of the width of the door opening, with the central panels each being about one third of the door opening width. The present bi-folding door system includes various novel features, including means allowing the doors to be opened manually without disengaging the doors from their drive tracks or requiring the door system to be reset after such manual operation.
2. Description of the Related Art
Automatically actuated door systems are quite popular in many businesses and other establishments, due to their convenience for customers and others who have occasion to use the doors. Such automated doors can assist in the conservation of energy and maintenance of the interior climactic environment of the building by means of their automated closure systems, and may also provide greater security than conventional manually actuated door systems, regardless of their configuration.
A large number of different automated door configurations have been developed as a result of the above automated door needs, with various types of multiple panel doors which open and close in an “accordion style” operation being quite popular due to their relatively compact configuration when opened. It will be seen that such an arrangement requires that the door panels have a width of only half that of the door opening, where two equal width panels are used. This greatly reduces the space which would otherwise be required for a conventional, side hinged door comprising a single panel. Even more opening space can be saved by providing greater numbers of door panels, with multiple panels disposed to each side of the center of the door opening in a symmetrical array.
However, most multiple panel hinged door configurations have equal size panels. It will be seen that with the outermost jamb panels hinged to the door jambs to each side of the door opening, that the entire width of the door panels must swing to one side (i.e., inside or outside) of the door opening. This arrangement detracts greatly from the otherwise compact opening configuration which might be provided by centering the opened door panels within the door opening. Nevertheless, most manufacturers of multiple: panel doors prefer such equal panel door configurations, as such equal size door panels simplify the geometry of the actuating mechanism and the installation of the door assembly. This is particularly true when considering the various actuating systems of the prior art, where relatively complex mechanisms have been used to open the panels or to draw the panels to a closed position.
Another problem with such multiple panel, laterally and arcuately moving door panels, is that of providing for emergency egress in the event of an electrical power failure. Federal regulations require that any powered, automated door system be capable of being opened by applying a force of no more than a few tens of pounds, close to the center of the door(s). Generally, most automated door manufacturers have responded to this requirement by providing a relatively weak attachment point or link between the center area of the door at its top, and the associated track and drive structure. Thus, a person can push on the center of the door and break the door loose from its attachment in the event of an emergency and loss of power for the door. However, such systems require the door to be reinstalled with its retainer, before the automated function can be reactivated.
Accordingly, a need will be seen for an automated multiple panel door system which overcomes the above problems and further provides a relatively straightforward mechanism for doing so. The present bi-fold door system essentially comprises symmetrical, left and right jamb and primary panels, with the jamb panels having half the width of the primary panels. The jamb panels are hinged to the door jamb or frame along their jamb edges, while the primary panels pivot arcuately about their vertical centerlines as they are moved laterally in the door frame. This configuration results in only about one sixth of the total door width disposed to each side of the door frame when the panels are opened, thus saving substantial room which would otherwise be required for opening the doors.
The present bi-fold door system also responds efficiently to the requirement for emergency egress, with the central edges of the two center or primary panels initially swinging outwardly as the doors are actuated for opening. A manual force of less than thirty pounds is required for a person to push the two central panels open, against the mechanical resistance of the drive belt, transmission, and motor connected thereto. The present bi-fold door retains the mechanical relationships between all components when opened manually, and does not require a person to reset or realign any components after manual opening. Moreover, the present bi-fold door introduces a much more elegant mechanical means for “breaking,” i. e., deflecting the plane of the door from the plane of the door frame, at initial opening, in order to reduce linear stresses on the door track drive system.
A discussion of the related art of which the present inventor is aware, and its differences and distinctions from the present invention, is provided below.
U.S. Pat. No. 4,106,544 issued on Aug. 15, 1978 to Guy E. Dixon et al., titled “Electrically Operated Folding Partition,” describes an asymmetrical multiple panel folding door having a single half width jamb panel hinged to one jamb, with a series of full width folding panels extending therefrom and across the entire door opening when the door is closed. Dixon et al. require a relatively complex actuation system which initially pulls the doors more tightly closed to align the hinges, before the door may be opened. Positive closure is provided by an essentially opposite action, in which inertia moves the doors past the aligned hinge position and the drive motor then applies a slight opening force to compress the panels along their coplanar disposition within the door frame. Dixon et al. are silent regarding manual opening of their door system, but it appears that the Dixon et al. door system cannot be completely opened by a push upon the central panel(s) in the event of a power failure, as the lead panel is held in a coplanar orientation with the door frame by means of a pair of guides. In contrast, the present bi-fold door invention is symmetrical, and may be completely opened manually by pushing on the central panel(s) of the assembly. Moreover, the motorized opening and closing system of the present door system is greatly simplified over that of the Dixon et al. system, obviating any requirement for additional slight actuating motions to initiate is door opening or closing.
U.S. Pat. No. 4,534,395 issued on Aug. 13, 1985 to William F. Carroll, titled “Folding Door,” describes a bi-fold door system wherein the jamb panels are somewhat wider than half the width of the primary panels. This results in the primary panels being asymmetrically disposed within the door frame when the door is opened, unlike the present bi-fold door system. Moreover, as the hinge lines between the two panels on each side fold outwardly, the center edges of the two primary panels move inwardly during normal operation; they cannot be pushed outwardly during manual operation, without disconnecting the doors from their automatic operating mechanism. A mechanic or other person would be required to reset the two primary panels in their ball detent retainers, after manual opening of the Carroll door system. In contrast, the present bi-fold door system moves the hinge lines between each jamb panel and main panel inwardly, thus displacing the central edges of the two central panels o
Cline John
Gebert Hal
Johnson Blair M.
Litman Richard C.
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