1. Field of the Invention
This invention relates to safety barriers in general and in particular to a variety of portable safety barriers which may be selectively attached across a restricted passageway.
2. Description of the Prior Art
Typical of prior art bar barriers is, for instance, Delany U.S. Pat. No. 389,206 which discloses the use of a guard bar to prevent entry into a basement stairwell. That particular bar may be locked in position and then subsequently slid out of the way. Typical also are Claus U.S. Pat. No. 1,891,588 and Bolton U.S. Pat. No. 3,648,4225. The Claus patent discloses a window safety bar which telescopes to fit windows of varying widths. Similarly, Bolton discloses an adjustable bridging device which is extensible and which includes a pointed end. Of interest, also, is Cleveland U.S. Pat. No. 3,425,165 which discloses an extensible gate for preventing accidental spills down open elevator shafts.
With regard to a cord type barrier, the following examples of prior art are of particular interest: U.S. Pat. Nos. Garrett et al 3,408,771 and Ellison 2,663,103. Garrett et al is significant because it discloses the use of a rope or cord for excluding unwanted traffic from an isle.
In view of the foregoing, it is clear that the use of a simple bar or cord for preventing undesired traffic through a passageway or up or down a stairwell is known in the prior art. However, the advent of new safety requirements as, for instance, spelled out in recent OSHA regulations make such simple expedients obsolete.
The OSHA regulations dealing with floors, wall openings and stairways, may be found in Part 1926, Subpart M, Sections 1926.500-1926.502 of Title 29 of the Code of Federal Regulations. The foregoing regulations may also be found reprinted in the Federal Register, Volume 37, No. 243, Saturday Dec. 16, 1972 at Pages 27543-27545. Besides imposing rigid regulations as to the dimensions of stairwell barriers, the OSHA regulations also impose a minimum 200-pound top rail pressure on safety barriers. It is doubtful if many of the prior art type safety barriers could successfully meet the requirements set forth in the new OSHA Federal Regulations. Not only does the present invention meet and surpass the OSHA requirements, the present invention is also highly adaptable for use in wide variety of environments.
A specific problem solved by this invention is that posed by the use of Unistrut U-shaped channels such as found in many powerhouses and often found in temporary structures under construction. (Unistrut is a trademark of the Unistrut Corporation of Wayne, Mich.) As a matter of fact, there may be up to a mile or more of U-type strut or 15/8 inches pipe support in the framework of a powerhouse whose outside structure may range up to 13 stories in height. Because there are no opposing walls, most prior art devices are inadequate. Additionally, barriers have to be much stronger than previously developed and have to be rigidly securable to U-strut supports. Moreover, such barriers have to be virtually tamper-proof and extensible so that they can fit in passageways of varying widths. It was in the context of the foregoing requirements that the following device was invented.