Flexible or portable closure – partition – or panel – Plural strip – slat – or panel type – With mounting or supporting means
Reexamination Certificate
1999-08-19
2001-05-08
Johnson, Blair M. (Department: 3634)
Flexible or portable closure, partition, or panel
Plural strip, slat, or panel type
With mounting or supporting means
C016S091000, C049S197000
Reexamination Certificate
active
06227281
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates generally to a sectional door having a support track and support rollers and, more particularly, the present invention relates to a track safety system for use with sectional doors. More particularly still, the present invention relates to a sectional door having a shield apparatus as a safety device for the rollers engaged in the support track.
Sectional doors are used in various applications such as garage doors, storage doors, and industrial doors. A sectional door typically consists of a plurality of door sections that are hinged in an edge-to-edge relationship to form the completed sectional door. The ends of each door section are supported upon support rollers, which are confined to support tracks mounted adjacent the opening of the facility, such as a garage. Each support track has a vertical section and a horizontal section with a curved section, usually as part of the horizontal track, providing transition between the vertical and horizontal direction. The vertical section of track supports the sectional door in its vertical or closed position across the opening while the horizontal section supports the sectional door in its overhead or open position. The hinges between the door sections allow the sectional door to traverse the curved section of track between the vertical and horizontal orientations.
The support track is fabricated from a strip of sheet metal that has been formed with a generally J-shaped cross section so that the support roller is constrained by the curved portion of the J-shape. The axle of the support roller extends outwardly and is anchored to the adjacent door section. The upper end of the J-shaped cross section is formed as a flange extending orthogonally from the leg of the J-shape to provide the support track with an overall cross sectional profile that is a modified C-shaped profile. The curve of the J-shape supports the roller while the flange prevents the roller from jumping the track. Dimensionally, the length of the J-shape is about 5 or 6 centimeters while the width of the curved portion of the J-shape is about 3 centimeters. The flange is larger than 3 centimeters.
A primary use of a sectional doors is in a residential setting, which typically includes children playing in and out of the garage. Children enjoy playing with things that move, but do not always appreciate the inherent dangers of the object with which they play. For example, residential sectional doors are provided with electrically driven openers to move the sectional doors between their open and closed positions. On occasion, children insert one or more fingers into the interior of the “J” shaped track during movement of the sectional door, which results in one of the support rollers either severely crushing or amputating the child's fingers. Further, the support roller has a diameter of less than 5 centimeters, which means that the angular opening between the periphery of the support roller and the support track is sufficient to receive a child's finger. The size of a child's finger coupled with the dimensions of the support roller and support track tends to pull the rest of the child's finger under the support roller during the continued rolling movement of the support roller.
One solution to guarding against fingers being inserted in a support track near the support rollers is to provide a barrier in front of the support roller. An example of such a support barrier is illustrated in Patent Cooperation Treaty Application No. PCT/DK97/00339, published Mar. 12, 1998. This reference teaches of providing a finger blocking disc, which is made of plastic, at each roller. The disc extends beyond the free edges of the support track and is designed to prevent fingers from being carelessly caught between the stationary support track and one or more of the support rollers during the opening or closing of the sectional door. The disc has a hub that is mounted with a forced fit on the shaft to which the support roller is mounted. The disc is locked in place with a locking ring. The disc also has an enlarged bead about the circumference to prevent the disc from cutting into or harming any fingers that might stray within the support track.
Unfortunately, the PCT Application No. PCT/DK97/00339 suffers from several drawbacks. One drawback is that the edge of the roller track is a cut, bare metal sheet that has a sharp edge. This sharp edge can still cut the fingers of anyone placing their hand within the support track either with or without the support rollers pinching on the fingers. Secondly, the sharp edge of the support track can also cut the fingers of someone placing their hand within the support track by the protective disc, which can easily press the fingers along or into the sharp edge of the support track. Referring now to
FIG. 12
(PRIOR ART) support track
30
and roller assembly
20
are shown in the environment of a child's finger
40
. Portions of curved section
32
are broken away to schematically illustrate what happens when finger
40
is placed inside support track
30
during movement of roller assembly
20
. Movement of roller assembly
20
is shown schematically by movement arrow
42
that causes roller
22
to rotate as shown schematically by rotation arrow
44
. This rolling action of roller
22
grips the tip of finger
40
against the inside surface of curved section
32
thereby holding finger
40
from being retracted. Continued movement of roller assembly
20
causes roller
22
to ride over finger
40
with the net effect that finger
40
is “pulled” under roller
22
as shown schematically by pulling arrow
46
. Clearly, finger
40
is subjected to substantial injury by being crushed between roller
22
and the surface of J-shaped track section
32
. Additionally, if finger
40
is only pushed across the exposed edge of curved section
32
finger
40
will most probably be cut by this action.
Another disadvantage with the prior art disc is that the retaining ring and the flange used to secure the protective disc on the support shaft can work loose causing the protective disc to move away from the opening in the support track. Without the protective disc guarding the support track in close proximity, fingers can get caught in the track as the door operates by being caught by the support rollers moving within the support track.
Another drawback with the disk disclosed in PCT Application No. PCT/DK97/003339 is that the disk must be sufficiently large in order for fingers not to come in contact with the support rollers during travel. This means that the disk can extend over the track portion and be broken if it is made of an inferior material. Further, children can be imaginative enough to insert something long and thin that rides in the track and is not deflected out of the track during travel. Such an item may be a stick, a toy, or the like. Failure to deflect the object could lead to a damaged track or roller, or to a stuck door that is inoperable.
Furthermore, the metal tracts in which the guide rollers travel typically have openings in them that are used for security purposes. Namely, a latch fits into one of the openings to hold the door in place. The latch can be released by a handle with a lock on it. This provides a means for locking and securing the door in a closed position. Unfortunately, a garage door opener is used in many cases to provide this security feature. Thus, the universal track with the latch openings allows a child to insert his or her fingers through the track during operation, which has been shown previously to lead to injured or severed fingers.
Accordingly, what is needed is a complete safety system for a sectional door that includes an improved protective device for shielding the support rollers and support track to prevent injury by cutting or being pinched along the support track or between the support track and the support rollers. Furthermore, what is needed is a protective device that is secured on the support shaft near the support track and
Broadbent Berne S.
Hulse Dale E.
Johnson Blair M.
Kirton & McConkie
Martin Door Manufacturing, Inc.
LandOfFree
Sectional door with roller shield apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Sectional door with roller shield apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Sectional door with roller shield apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2519930