These teachings relate to construction and maintenance worker safety at industrial, commercial and other types of building work sites. More particularly, disclosed herein is an engineered fall-arrest mechanism that stops the free fall of up to two workers simultaneously at a job site.
Building owners are responsible for providing a safe work environment for all employees, subcontractors and other workers. The failure of businesses to provide a safe work environment can cause excessive liability and other financial exposure.
Currently, roof top anchorages (otherwise known in the industry as “tie-offs”), requiring expensive field welding and extensive deck cutting and reinforcing, are widely employed as a method of worker safety for breaking falls at building and construction sites. Generally, workers are harnessed and tied off to a single rooftop anchorage that would break a potential fall. The welding, deck cutting and reinforcing of the currently employed systems significantly add to time spent at a site and increase the labor costs, fire hazards, and risks of incorrect installation. Furthermore, safety posts (roof top anchorage/tie-offs) also have to meet the requirements of the Occupational Safety and Health Organization (hereinafter referred to as “OSHA”) as described in Safety and Health Regulations for Construction (Part 1926), subpart M (Fall Protection), standard 1926.502, entitled Fall Protection Systems Criteria and Practices, paragraph d, Personal Fall Arrest Systems, and, optionally, as described in Appendix C to this regulation entitled Personal Fall Arrest System—Non-Mandatory Guidelines for Complying with 1926.502(d).
Current safety mechanisms fall short of providing optimum effectiveness in dealing with cost and space restraints. U.S. Pat. No. 5,553,685, issued to Cook, discloses a roof safety anchor attachable to a rafter or joist. This anchor is securable to a single lifeline. For projects requiring a number of roof workers, space constraints and safety concerns prohibit the installment of significant number of safety anchors similar to the system disclosed in Cook. Many fall arrest systems, including that of Cook, require the drilling of a plurality of nails and screws into the supporting structure that weaken the beam or rafter to which the arrest system is secured.
Roof anchors such as that disclosed by Curtin in U.S. Patent Application Publication No. 2004/0035993 Al, now U.S. Pat. No. 6,966,531, contain a large number of components, which can lead to faulty installation at a work site. These anchors also tend to be bulky and inefficient for a work site with significant space constraints.
Therefore, it would be beneficial to have a superior system for fall arrest safety.
The needs set forth herein as well as further and other needs and advantages are addressed by the present embodiments, which illustrate solutions and advantages described below.
In one form of the present teachings, a fall arrest safety system is disclosed comprising an eye bolt having a proximal portion and a distal portion wherein the distal portion is partially threaded; an energy absorption mast located at the proximal portion having an upper assembly and a lower assembly, wherein the upper assembly includes a washer, an internally threaded fastener, and a plate, and wherein the lower assembly comprises a retainer, a washer, and at least one internally threaded fastener; a ring formed at the top of the energy absorption mast; and a slotted plate assembled over the ring.
In another form of the present teachings, a fall arrest safety system is disclosed comprising an eye bolt having a proximal portion and a partially threaded distal portion, the proximal portion having an upper assembly and a lower assembly, wherein the upper assembly includes a washer, an internally threaded fastener, and a first plate, and wherein the lower assembly comprises a retainer, a washer, and at least one internally threaded fastener; a jacket sub-assembly connected to the eye bolt and within the upper assembly, wherein the jacket subassembly comprises a pipe having a top portion and a bottom portion, the top portion forming a weld joint with a second plate, and further wherein the first plate is sealed to the bottom portion of the pipe and located at the top of the partially threaded distal portion of the eye bolt; a ring connected to the top of the jacket sub-assembly; and a slotted plate assembled over the ring.
In yet another form of the present teachings, a fall arrest safety system is disclosed comprising a bolt having a proximal portion and a partially threaded distal portion, the proximal portion having an upper assembly and a lower assembly, wherein the upper assembly includes a water-tight washer, and a first plate, and wherein the lower assembly comprises a retainer, a washer, and at least one internally threaded fastener; a jacket subassembly connected to the bolt and within the upper assembly, wherein the jacket sub-assembly comprises a pipe having a top portion and a bottom portion, and further wherein a second plate is sealed to the bottom portion of the pipe and located at the top of the partially threaded distal portion of the bolt; and the first plate is horizontally sealed to the top portion of the jacket sub-assembly.
In yet another form of the invention, a fall arrest safety system, is disclosed comprising a steel bolt having a proximal portion and a distal portion wherein the distal portion is partially threaded an eye bolt of a predetermined diameter having a proximal portion and a distal portion wherein the distal portion is partially threaded; a bolt as a tension member configured at the proximal portion, the bolt as a tension member having an upper jacket sub-assembly and a lower assembly, wherein the lower assembly includes a retainer, a lock washer, a washer, and two internally threaded fasteners; a ring configured at the upper assembly of the; a slotted plate assembled over the ring; and a jacket sub-assembly encompassing the bolt as a tension member and surrounded by the upper assembly, the jacket sub-assembly having a top hollow member portion of a slightly larger diameter than the bolt as a tension member and a bottom plate with a hole allowing the tension member to pass through the plate, the top portion secured by a weld joint with the plate.
A key feature of the present teachings is the use of a bolt as a tension member. The present teachings can be configured such that the tension member and the resultant compression forces to provide secure attachment of the product and break of falls, eliminate the need for welding and expensive reinforcing, and create a pre-fabricated system easy to install in the field. The present teachings also can eliminate expensive field welding and extensive deck cutting and/or additional structural reinforcing on new buildings resulting in cost savings via the tensioned installation of the system through either a beam or a joist girder. The present teachings can further provide a system that is light-weight and has a minimal number of components to ease the installation at site and reduce the chances of faulty installations. On existing buildings, these teachings could be economically installed through a membrane roof with minimal chance of leaks. The present teachings can eliminate the need for expensive field welding and in doing so can also eliminate the risks and fire hazards associated with these activities. The present teachings can provide a system that does not use any nails, screws or other non-customized attachment items. The lightness of the system can further eliminate the additional reinforcement of the building frame which may be required with other heavier systems. The present teachings can eliminate the use of stringing cables between the units where the workers are tied off. Since no suspended cables are present, potential tripping hazards from such systems are also eliminated. The present teachings can provide a specific design for breaking the fall of a worker on a construction site to meet the OSHA requirements, and is not a simple piece of equipment for tie-off like an anchor.
If a repair or replacement is necessary, this can be easily seen since the unit is not encapsulated. The present teachings disclose that the energy of a potential fall is absorbed through the material of a first embodiment of the present teachings, and wear and tear can easily be seen and the unit be replaced. The present teachings disclose a system that can be used on steel frames after a steel frame is erected, and not during the construction of a frame.
The first embodiment of the present teachings can deflect and absorb some of the energy of the fall, further protecting the worker from stress applied by the worker's harness during the fall event.
For a better understanding of the present embodiments, together with other and further aspects thereof, reference is made to the accompanying drawings and detailed description, and its scope will be pointed out in the appended claims.
The present teachings are described more fully hereinafter with reference to the accompanying drawings, in which the present embodiments are shown. The following description is presented for illustrative purposes only and the present teachings should not be limited to these embodiments.
As required, detailed embodiments of the present teachings are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the teachings, which may be embodied in various forms. Therefore, specific structural and functional details disclosed herein 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 teachings in virtually any appropriately detailed structure.
The system of the present teachings can include, but is not limited to including, upper and lower assembly units corresponding to above and below planes of the fixed and rigid installation points. Four embodiments (e.g. ALIEN™, ALIEN SS™, STREET ALIEN™, and JACKETED ALIEN™) can be installed at girders fabricated from wide flange sections and/or at joist girders. The minimum flange requirement is at least 0.45 inches and girders must be properly connected at ends.
One of the advantages of the system is that the various embodiments can be installed at the site without welding like most of the rooftop fall arrest systems require today. The system of the present teachings also does not require an additional beam or trolley assembly like the carabineers (providing self-retracting lifelines) that is assembled to a fall protection trolley. Each embodiment may be designed to anchor two employees using the proper safety lanyard, harness and any other appropriate gear. The present embodiment is calculated to have a shear rupture value of over 11,000 pounds and a tension rupture value of over 19,000 meeting or exceeding the OSHA Requirements for Construction (Part 1926, Subpart M).
Since the installation of any of the embodiments of the teachings is not limited by welding or an extraneous crane or trolley beam, the present embodiment can easily be distributed across the entire construction or steel erection site simply by installing as many units of the present embodiment as necessary for the job. The four embodiments of the present teachings can be made a part of the permanent structure after an assessment conducted by a person responsible for installing and inspecting the system of the present teachings.
Since the employees anchored to the present embodiment generally use a safety lanyard, harness and appropriate gear such as retractable lifeline, their range of reach will be limited by the type of accompanying equipment they use. The system of the present teachings is a stationary unit and should not be removed to a different location once installed. The anchorage unit does not glide along the beams like some beam trolleys may provide today. It should be noted that the present teachings will stop the fall, but not necessarily eliminate all the injuries that may be inflected by the actual fall and surrounding structures.
The system can include, but is not limited to including, a partially threaded rod or bolt roughly two feet in length. The threaded portion (bottom portion) is one foot long allowing installation through an assembly hole in a beam or the gap between the top chord members of a joist girder. The system is secured with a channel, a washer and two (a plurality of) nuts assembled and tightened at the distal end of the threaded portion of the rod. These components are referred to as the lower assembly components hereafter. The other side of the tightened assembly (at the proximal threaded portion of the rod) is supported by either a nut, washer and plate combination or a square or round plate belonging to a jacket sub-assembly, depending on the embodiment of the present teachings.
The non-threaded portion of the system (top portion) is roughly one foot in length and terminates in a mechanism (e.g., the “alien face” in each embodiment) for attachment of the workers' safety harness line. Depending on the version of the invention, the top portion is also used to house a jacket sub-assembly that reinforces the system against bending forces to meet the OSHA non-mandatory requirements for a non-engineered mechanism. Engineering calculations have been performed for device jacket sub-assemblies to verify that the device as shown in
All four described embodiments incorporate a plate under the channel and use double nuts. In the STREET ALIEN™ system, depicted in
Additionally, the circular plate 400 that is referred to as the ALIEN™ system in the
With respect to
The upper assembly components, depicted in
The ALIEN™ embodiment depicted in
The stainless steel rod 300 of the second embodiment of the present teachings, known as ALIEN SS™ (
The upper assembly components in the ALIEN SS™ system consist of a jacket sub-assembly 900 containing circular plate 400, a pipe 800, and a square plate 600 (illustrated in
The lower assembly components located at the distal threaded portion of
The ALIEN SS™ embodiment is designed such that as the assembly components are tightened, a tensile force is established through a majority of the length of the main rod 300. Specifically, the tensile force in the rod is established from the level of the lower assembly components 500, 801, and 802 to the level of the weld joint 901 of the circular plate 700 at the top of the jacket sub-assembly 900. Consequently, in accordance with the equilibrium of forces in a system, an equivalent compressive force is established through the length of the jacket sub-assembly 900. Specifically, the compressive force is established form the weld joint 901 of the circular plate 700 to the bottom of square plate 600.
Upon loading of the safety harness line, presumably by the fall of a worker, a load would be transferred to the attachment mechanism (the ring 401 and the circular plate 700) and to both the pre-tensioned main rod 300 and the pre-compressed jacket sub-assembly 800 in the form of a bending force. The ALIEN SS™ embodiment is designed such that critical bending forces exerted on the system do not lead to excessive deflection or to yielding of the system. This design makes the ALIEN SS™ compatible with the OSHA non-mandatory requirement for non-engineered systems. See
The galvanized bolt 1304 of the third embodiment of the present teachings, known as the STREET ALIEN™ system (illustrated in
The bottom of the pipe 1301 is, in turn, welded to the top of the circular plate 1000 with a square hole. In
The lower assembly components of the third embodiment of the present teachings known as the STREET ALIEN™ system are located at the distal threaded portion and include a steel channel member 1100 detailed in
The STREET ALIEN™ embodiment is designed such that as the assembly components are tightened, a tensile force is established through a majority of the length of the bolt 1304. Specifically, the tensile force in the bolt 1304 is established from the level of the lower assembly components to below the head of bolt 1304. Consequently, in accordance with the equilibrium of forces in the system, an equivalent compressive force is established through the length of jacket subassembly 1300. Specifically, the compressive force is established from the top of the rectangular plate 1200 to the bottom of the circular plate 1000. Upon loading of the safety harness line, presumably by the fall of a worker, a load would be transferred to the attachment mechanism (the rectangular plate 1200) and to both the pre-tensioned bolt 1304 and the pre-compressed jacket sub-assembly 1300 in the form of a bending force.
The STREET ALIEN™ version is designed such that critical bending forces exerted on the system do not lead to excessive deflection or to yielding of the inventive system. It is important to note that this design makes the STREET ALIEN™ system compatible with the OSHA non-mandatory requirement for non-engineered systems. See
Referring now to
The upper jacket sub-assembly 2100 in the JACKETED ALIEN™ consists of hollow member 2110 and a square plate with a hole 2120 to allow the mast to pass through the jacket. The hollow member is a 1 foot-¾″ long pipe is connected to the 3 inch by 3 inch plate through the welded joint 2130. All components are made of carbon steel ASTM A53 grade B or ASTM A500, grade B or C. All members of this device can also be manufactured of stainless steel and members can also be treated with primer, galvanized or other coatings.
Continuing to refer to
The JACKETED ALIEN™ embodiment is designed such that as the assembly components are tightened, a tensile force is established through a majority of the length of the main rod 300. Specifically, the tensile force in the rod is established from the lower level components 200, 303, 304 and 305 to the level of the head 401. Consequently, in accordance with equilibrium of forces in a system, an equivalent compressive force is established through the length of the jacket sub-assembly 2100.
Upon loading of the safety harness line, presumably through the fall of a worker, a load would be transferred to the attachment mechanism and to both the pre-tensioned main rod 300 and the pre-compressed jacket sub assembly 2100 in the form of a bending force. The JACKETED ALIEN™ embodiment is designed such that critical bending forces on the system allow for some deflection or bending but minimize the yielding experienced in the base version of the invention. All versions or components of choice can be made from stainless steel, carbon steel with galvanization or carbon steel without galvanization. What is further illustrated is the assembly of the JACKETED ALIEN™ system of the present invention in a joint girder 1900 (
Referring now to
Referring now to
It will be readily apparent to those skilled in the art that various changes and modifications of an obvious nature may be made, and all such changes and modifications are considered to fall within the scope of the appended claims. Other embodiments of the present teachings will be apparent to those skilled in the art from consideration of the specification and practice of the present teachings disclosed herein. In particular, it is noteworthy that the plates in the four embodiments may be any geometric shape. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the present teachings being indicated by the following claims and their equivalents.
While the present teachings have been described above in terms of specific embodiments, it is to be understood that they are not limited to these disclosed embodiments. Many modifications and other embodiments will come to mind to those skilled in the art to which this pertains, and which are intended to be and are covered by both this disclosure and the appended claims. It is intended that the scope of the present teachings should be determined by proper interpretation and construction of the appended claims and their legal equivalents, as understood by those of skill in the art relying upon the disclosure in this specification and the attached drawings.
This application is a continuation-in-part of and claims the priority date of Utility application Ser. No. 11/138,637, entitled ALIEN FALL ARREST SAFETY SYSTEM, filed on May. 26, 2005, which claims the priority date of Provisional Application Ser. No. 60/577,106, entitled ALIEN FALL ARREST SAFETY SYSTEM FOR STEEL ERECTION SITES TECHNICAL REPORT, filed on Jun. 4, 2004, both of which this application incorporates by reference in their entirety.
Number | Date | Country | |
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60577106 | Jun 2004 | US |
Number | Date | Country | |
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Parent | 11138637 | May 2005 | US |
Child | 12703577 | US |