1. Field of the Invention
This invention generally relates to a safety net arrangement for catching objects falling down open shafts and, more particularly, to catching workers and/or items encountered at a construction site falling down elevator shafts or like open passages in multi-floor buildings under construction.
2. Description of Related Art
During the construction of a multi-floor building having elevators, it is known to position metal or wood decks, or even steel beams, directly over an elevator shaft in order to protect workers from falling down the shaft and/or to prevent construction materials or like items encountered at a construction site from being dropped, either accidentally or deliberately, down the elevator shaft. However, elevator workers requiring free access for the elevator cabin object to such blocking of the elevator shaft. Hence, the shaft is blocked at some times and unblocked at other times. The rigid covering of an elevator shaft, of course, provides no real crash protection for a worker who hits the rigid covering from an elevated height.
It is also known to position metal or wood railings around the elevator shaft in an attempt to deny access thereto. However, the installation of railings is a rather expensive and labor-intensive procedure which must be installed for each floor to be truly effective. Access to the shaft may also be blocked by ropes around the elevator shaft, but, here, again, the ropes need to be installed at each and every floor, and objects still pass over or under the ropes into the elevator shaft.
It is also known to tautly string a net at the top of an elevator shaft to protect ironworkers working on the top floor of a building. However, this does not protect workers entering the shaft at a lower floor and, in any event, some objects falling from an elevated height into a tautly strung net can generate enough force to actually tear and pass through the net, thereby providing no real crash protection at all.