Fences – Rail
Reexamination Certificate
2001-03-01
2003-06-17
Knight, Anthony (Department: 3676)
Fences
Rail
C256S024000, C256S073000, C256S065140
Reexamination Certificate
active
06578827
ABSTRACT:
FIELD OF THE INVENTION
The invention relates to temporary safety handrail systems that may be quickly and easily erected or removed and, in particular aspects, the invention relates to handrail systems that use weighted counterbalancing.
DESCRIPTION OF THE RELATED ART
Temporary safety handrails are important to provide protection against falling for workers on building roofs. These structures also help prevent equipment or items from falling or being blown off of roofs and injuring individuals below. Safety rails generally, of course, are useful in many other situations as well.
Some temporary handrail systems are known that use weighted counterbalancing to stabilize the handrail. U.S. Pat. No. 5,145,153 issued to Glynn and entitled “Portable Handrail Counter-Weight System” describes a modular portable handrail system that employs cantilever arm/counter-weight anchor assemblies. Unfortunately, this system has a number of problems that limit its effectiveness. For example, the system has roof-contacting portions with sharp corners and edges that can damage the roof membrane and cause the roof to leak.
U.S. Pat. No. 4,909,483 issued to Van Herpen and entitled “Support for the Handrail of a Detachable Handrail Unit” describes a safety handrail for the tops of buildings and the like. The rail has several “bases” that are horizontally disposed offset legs that rest upon the rooftop. The ends of offset legs are weighted down by placing weights onto the leg and the rooftop surface. Because the weight and the base both contact the roof, they can cause damage to the roof membrane from their sharp corners and edges.
Conventional weighted handrail systems have other disadvantages in operation. The weights in these systems are generally applied only to the offset end of the horizontal leg. This is an inefficient means of anchoring a rail in place. The rail may be pulled or pushed backwardly and lifted off of the roof. The weighted end of the leg can act as a fulcrum about which the rail assembly could rotate. As a result, stability of the rail is problem.
Many conventional weighted handrail systems also fail to adequately distribute weight loads across the surface of a roof. As a result, significant amounts of weight are applied to specific points on the sometimes delicate roof membrane thereby resulting in damage to the rooftop.
It would be desirable to have systems and methods that address the problems associated with the prior art.
SUMMARY OF THE INVENTION
The present invention is directed to methods and devices for providing temporary handrail systems. In a preferred application, the handrail systems of the present invention are used to surround the periphery of a building rooftop. A number of handrail sections are reversibly interconnected to one another to form a continuous protective rail. In practice, the rail is quite stable and resistant to tipping.
In exemplary embodiments, the handrail systems of the present invention feature load-distributing support bases and weight support platforms. Weights are selectively added to the weight support platforms to anchor the handrail in place. The weight support platforms are located above the surface of the roof and do not contact the roof surface. The weight load is transmitted via support legs downwardly to load-distributing support base that is placed in contact with the roof. The support bases are substantially devoid of sharp edges and corners and distribute the weight load so that point loading is not a problem. As a result, the roof membrane is not damaged by a point load applied to it. In addition, a portion of the weight load from the weight support platform is transmitted directly to the vertical support rails of the rail sections. Thus, the rails are more securely anchored in place and have greater resistance to movement of the rail either forwardly or backwardly.
The handrail arrangement of the present invention offers improved stability over conventional systems. The rail sections readily interlock to form a continuous rail. The interlocking structure also allows the rail sections to be angled with respect to one another. The interlocking feature increases the stability of the rail.
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Bannapradist Lisa
Hunter Shawn
Knight Anthony
Madan Mossman & Sriram P.C.
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