Patent Application
20140020853
This invention relates generally to closure curtains and in particular, to a closure curtain with a bumper centering device.
Access openings, such as entranceways, doorways, hallways, and areas above countertops are often secured by overhead (vertically traveling) closures.
Rolling steel doors, also referred to as overhead coiling closures, are metal slatted doors which move in a generally vertical path, coiling above the opening as the door is opened. Because rolling steel doors have many fewer parts than sectional doors with less risk for damage and inoperability, they often make a better solution for facilities that cannot afford opening downtime.
Rolling grilles also coil above the opening and provide access control and off hour security on interior and exterior openings, but unlike rolling steel doors simultaneously permit visual access of separated spaces. Grilles prevent unauthorized access and discourage forced entry at building exterior openings, storefronts or areas within buildings, such as pharmacies or parts counters. Used behind plate glass storefronts, they are a deterrent to smash-and-grab crime.
Rolling counter fire doors, also referred to as fire shutters, coil above the opening and are used to secure openings above counters and other similar finished openings on interior and exterior walls. When the compact components of counter fire doors are desired, these units can fully close to the floor.
All of the aforementioned overhead coiling door designs travel within a pair of tracks positioned on either side of the opening. Usually rollers are not utilized. Because there are no rollers extending from the sides of the curtain, the curtain can have a tendency to move off center as it is being raised or lowered. Off center operation increases the likelihood that operative movement will not be smooth, and in extreme circumstances jamming can occur.
Accordingly, there is still a continuing need for improved curtain centering designs. The present invention fulfills this need and further provides related advantages.
In a preferred embodiment, a plurality of bumpers are spaced and fixed along the sides of the closure curtain of an overhead closure. In a first preferred embodiment, the geometry of the bumper is such that the vertical side and the extending sides meet in one or more obtuse angles.
In a second preferred embodiment, the geometry of the bumper is such that the vertical side and the extending sides meet in a radius.
One advantage of the novel technology is that the closure curtain remains centered to prevent jamming.
Another advantage of the novel technology is that smooth travel of the closure curtain within the tracks is maintained.
Yet another advantage is that the novel technology reduces wear on the coil brackets, the ends of the curtain and other component parts.
Other features and advantages of the present invention will be apparent from the following more detailed description of the preferred embodiments, taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention.
The accompanying drawings are included to provide a further understanding of the present invention. These drawings are incorporated in and constitute a part of this specification, illustrate one or more embodiments of the present invention, and together with the description, serve to explain the principles of the present invention.
Other features and advantages of the present invention will be apparent from the following more detailed description of the preferred embodiments, taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention.
As required, detailed embodiments of the present invention are disclosed; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various forms. The figures are not necessary to scale, and some features may be exaggerated to show details of particular components. Therefore, specific structural and functional details disclosed are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention. Where possible, like reference numerals have been used to refer to like parts in the several alternative embodiments of the present invention described herein.
Turning now to
The operator, generically identified at element 8 may be either manually powered (via, for example, push-up/pull-down, a hand chain, or a hand crank) or motor powered, and comprises a counterbalance shaft 12 upon which the closure curtain 14 winds and unwinds.
The counterbalance shaft 12 supports the closure curtain 14 and assists in the operation. Such assistance is, for example, provided by a counterbalance tensioner, for example, a torsion spring, generically identified as element 16. A bracket 18 is mounted, for example, to each guide assembly 4, 6 and supports the counterbalance shaft 12 and closure curtain 14. A protective hood 20 encloses the closure curtain 14 and provides both weather resistance at the head of the door 2 and helps to keep the brackets 18 rigid.
The first and second guide assemblies 4, 6 support the weight of the closure curtain 14. They may be, for example, a two piece extruded aluminum side rail assembly 22 (
The closure curtain 14 has a top, a bottom, and an articulated central section between the top and the bottom, for example, an open pattern curtain design (
Turning to
Bumpers 40 comprise an engagement part 46 comprising two extending sides 52 which extend meet a vertical side 50. The engagement part 46 operatively engages the guide assemblies 4, 6. The geometry of the bumper 40 may be any shape that allows the bumper 40 to travel within the guide assemblies 6, 8 without binding.
Shown in
In a second preferred embodiment shown in
The bumpers 40 are spaced to operatively keep the closure curtain 14 centered. The bumpers 40 are spaced preferably about every 4 inches to about 20 inches, most preferably, about every 12 inches along the closing curtain side 36. However, any distance between bumpers 40 that maintains effective centering is contemplated.
In a preferred embodiment, the bumpers 40 are fabricated from materials having a dry surface coefficient of friction, below that of steel on steel. For example, a dry surface coefficient of friction of less than about 0.30-0.40 Static and about 0.25-0.35 Kinetic, such as ultra high molecular weight polyethylene (UHMW).
The door 2 operates by pushing or pulling the closure curtain 14, or by manual or power rotation of the counterbalance shaft 12, for example, at a gear end 30 (
The closure curtain 14 is attached to the counterbalance shaft 12 and rolls onto and off of the counterbalance shaft 12 as the counterbalance shaft 12 is rotated. The closure curtain 14 travels within the vertically oriented guide assemblies 4, 6, within which the bumpers 40 are contained and guided.
Although the present invention has been described in connection with specific examples and embodiments, those skilled in the art will recognize that the present invention is capable of other variations and modifications within its scope. These examples and embodiments are intended as typical of, rather than in any way limiting on, the scope of the present invention as presented in the appended claims.
