This patent generally pertains to doors and, more specifically, to doors that can be periodically washed down to kill bacteria and other microorganisms.
General-purpose, vertically operating doors often have a flexible curtain that opens by rising from a vertical set of tracks installed alongside a doorway. Upon rising, the curtain transfers from the vertical tracks over to an overhead storage system. The actual design of the storage system may vary depending on the available space above the doorway and other considerations. An overhead storage system, for example, can be in the form of a take-up roller that draws in the curtain to open the door, or the storage system can be a set of horizontal, vertical, inclined, or coiled tracks that lead to the set of vertical tracks alongside the doorway.
Some vertically operating doors also include some type of protective breakaway feature that allows the curtain to temporarily separate from its guide tracks in the event of a collision such as, for example, the door's curtain being accidentally struck by a forklift passing through the doorway while door is only partially open.
Due to a vertically operating door's numerous intricate parts such as the door's vertical tracks; seals; overhead storage system; breakaway feature; and even the curtain itself, which can be comprised of multiple interconnected sheets and perhaps a window, such doors can be difficult to keep clean in environments that demand cleanliness. Many doors in the food and drug industry, for instance, need to be periodically washed down and sanitized in order to prevent product contamination.
Certain examples are shown in the above-identified figures and described in detail below. In describing these examples, like or identical reference numbers are used to identify the same or similar elements. The figures are not necessarily to scale and certain features and certain views of the figures may be shown exaggerated in scale or in schematic for clarity and/or conciseness. Additionally, several examples have been described throughout this specification. Any features from any examples may be included with, a replacement for, or otherwise combined with other features from other examples.
Vertically operating doors include numerous intricate parts such as the doors' vertical tracks; seals; overhead storage system; breakaway features; and even the curtain itself, which can be comprised of multiple interconnected sheets and perhaps a window. As a result, these doors can be difficult to keep clean in environments that demand cleanliness. Simpler doors might be easier to washdown; however, such doors lack the benefits of the otherwise preferred doors that have more features.
Although the actual design details and operation may vary, door 10 is shown comprising a curtain 26 that moves vertically along tracks 18 to open and close the door 10.
In the illustrated example, curtain 26 is powered open and closed by a drive motor 42 that rotates a horizontal shaft 44. At either end of horizontal shaft 44, a cogged drive wheel 46 meshes with a series of protrusions 48 on lateral edges 50 of curtain 26. Depending on the cogged drive wheel's 46 rotational direction, cogged drive wheel 46 pushes curtain 26 up to open door 10 or down to close the door 10. Alternatively, the cogged drive wheel 46 could have protrusions (not shown) that mesh with a series of matching holes (not shown) in the lateral edges 50 of the curtain 26. Many other ways of powering a door open and closed are certainly within the scope of this disclosure.
Referring to
To avoid retaining stagnant water or other liquids and to enable drainage of any low-lying pockets, the inside lower surfaces of spiral groove 14 preferably are curved or inclined with a drain passageway 62 of some sort leading from those surfaces. Drain passageway 62, for example, can be a drilled hole 64 leading to a lowermost point 66 of wider area 60, and/or drain passageway 62 may include an opening 68 (
Referring to
To seal off air currents 84 that might otherwise leak past through ventilating air gaps 78, removable seal 20 extends between track 18 and wall 34, as shown in the example, and/or removable seal 20 extends between side frame 16 and wall 34. In either case, removable seal 20 is removably coupled to side frame 16. The term, “removably” means the part is intentionally constructed such that it can be detached and later reattached without appreciable damage, wherein detaching is by way of disassembly as opposed to cutting, breaking or melting apart. Although track 18 and side frame 16 are shown as two separable pieces, which provides an important benefit, track 18 and side frame 16 could be a unitary piece, whereby side frame 16 would integrally include track 18. Whether side frame 16 and track 18 are separable or a single piece, track 18 is still referred to as being “disposed on” side frame 16.
By having track 18 and side frame 16 being separate pieces, as shown, side frame 16 can be heavy and strong for supporting door 10, while track 18 can be of a plastic material that is lightweight and readily removable. Removing track 18 and removable seal 20 opens up ventilating air gaps 78 between wall 34 and side frame 16 so that those now-open areas can be washed periodically, and the removed parts can be washed separately. To facilitate frequent washings, track 18 preferably is “hand-removable,” which means that track 18 can be removed manually without using tools. To render track 18 hand-removable, track 18 is fastened to side frame 16 by way of a knurled nut 86 or wing nut that screws onto a screw 88 having a head 90 held within track 18.
Although track 18 and removable seal 20 can be removed as a unit, the two pieces 18 and 20 preferably are a three-part assembly comprising a track case 18a, a track liner 18b, and removable seal 20. By having three individual parts 18a, 18b and 20, each piece 18a, 18b and 20 can be made of a material that is particularly suited for its intended purpose. Track case 18a, for instance, can be made of polycarbonate because this plastic exhibits high impactability, broad temperature stability, is inherently non-corrosive, and can be flexed repeatedly and resiliently. The resilient flexibility enables the curtain's 26 lateral edges 50 and protrusions 48 to be forcibly yet restorably pulled out from within track 18 in the event of a forklift-curtain impact, thereby avoiding damage to door 10. Track liner 18b can be made of UHMW (ultra high molecular weight polyethylene) for its excellent wear resistance. Removable seal 20 can be made of a neoprene, latex, silicone or similar rubbery material that can readily conform to the surface of wall 34. All three parts 18a, 18b and 20 preferably are made of polymeric materials so that the three-part assembly together is sufficiently lightweight (e.g., less than 50 lbs.) for hand-removal. For the illustrated example, track 18 includes a flange 92 that press-fits into a slot 93 in removable seal 20, thus removable seal 20 is hand-removable from track 18.
In
Returning to
For sake of example,
To avoid or minimize water dripping near the center of the doorway (e.g., doorway 28) from a lower edge 134 of curtain 26 and to seal off perhaps a rough cut edge 136 at the bottom of curtain 26, lower edge 134 can be finished as shown in
In some examples of the moisture-guiding seams 140 and 142 and ledges 100 and/or 132 (e.g., water-conveying ledges), it may be beneficial to have certain surfaces more water repellant than adjacent surfaces. The expression, “more water repellant,” as used herein means a surface having less strength of adhesion to water, thus water will tend to cling to surfaces that are less water repellant than to surfaces that are more water repellant. In the example of
At least some of the aforementioned examples include one or more features and/or benefits including, but not limited to, the following:
In some examples, a door with a pliable curtain includes an inclined seam that not only joins two component sheets of the curtain together but also provides a moisture-guiding ledge that directs curtain drainage toward a lateral edge of the curtain.
In some examples, a downward-facing ledge directs water along a downward slope off to a lateral edge of a door curtain.
In some examples, a door includes a curtain with a window, wherein water drains through a gap between a face of the curtain and a transparent sheet of the window.
In some examples, a door curtain has an inclined lowermost edge that is sufficiently pliable to lie flat against the floor when the door is closed.
In some examples, a door with a pliable curtain includes a seamless storage track machined from a single block of plastic, wherein the storage track includes a spiral groove with liquid drainage at all the low areas of the groove.
In some examples, a door includes a curtain guided by a vertical track, wherein the track is disposed on a side frame. A series of standoffs provides a washdown air gap between the side frame and the wall to which the frame is mounted. When not being washed down, a removable seal is installed to block off the air gap.
In some examples, a door includes a curtain guide assembly comprised of four main parts: a side frame, track case, track liner, and a seal, wherein each of the four parts are made of a different material.
In some examples, the curtain guide assembly is readily disassembled and reassembled without the need for tools.
Although certain example methods, apparatus and articles of manufacture have been described herein, the scope of the coverage of this patent is not limited thereto. On the contrary, this patent covers all methods, apparatus and articles of manufacture fairly falling within the scope of the appended claims either literally or under the doctrine of equivalents.
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20100218431 A1 | Sep 2010 | US |