CA2475829A1

CA2475829A1 - Energy absorber for horizontal lifeline system

Info

Publication number: CA2475829A1
Application number: CA002475829A
Authority: CA
Inventors: Toma Durbic
Original assignee: THALER METAL INDUSTRIES Ltd
Current assignee: Thaler Metal Ind Ltd
Priority date: 2004-07-23
Filing date: 2004-07-23
Publication date: 2006-01-23

Description

04-056CA.spec1.inc Energy Absorber For Horizontal Lifeline System FIELD OF THE INVENTION
[001] The present invention relates to the field of fall protection systems, and particularly, to an energy absorber for use in a horizontal lifeline system.
BACKGROUND OF THE INVENTION

[002] It is known to provide horizontal lifeline safety systems for workers on elevated structures.

[003] Such fall protection systems commonly consist of a horizontal lifeline anchored at its ends to a building structure, including ceilings, walls and roof structures, and supported intermittently along its length by intermediate supports.
Persons working in the vicinity of the lifeline may don a safety harness or belt and moveably attach to the horizontal lifeline via one or more mobile attachment devices. The mobile attachment devices freely move along the horizontal lifeline, including across the intermediate supports.

[004] It is well known to include means for absorbing energy in such horizontal lifeline systems, so as to ensure that the maximum arrest forces exerted upon persons using such fall protection systems do not exceed physically injurious levels, and also to reduce the force placed on the anchorages therefor to manageable levels.

[005] In modern fall protection systems, it is most common to utilize a substantially inelastic lifeline and to delegate energy absorption functionality to separate energy absorption apparatus that does not exhibit undesirable rebound.

[006] Energy absorption apparatus interposed between a horizontal lifeline and its anchorage are most commonly termed "energy absorbers", and energy absorption apparatus interposed between a lanyard and a harness are most commonly termed "shock absorbers" but the terms are used somewhat 04-056CA.spec1.inc interchangeably in the art, and indeed, many types of energy absorption apparatus are used interchangeably (to wit, in both applications). Accordingly, such apparatus are hereinafter referred to universally as "energy absorbers" for simplicity.
SUMMARY OF THE INVENTION

[007] It is an object of the present invention to provide an energy absorber for use in a horizontal lifeline system, which is of relatively simple and inexpensive construction as compared to devices of similar functionality of the prior art.

[008] This object, among others, is attained by the present invention, an energy absorber for use in a horizontal lifeline system.

[009] In one aspect of the invention, the energy absorber comprises an elongated non-elastic plate folded onto itself in an angled configuration. At least two and preferably three parallel rows of fasteners connect the two adjoining wall portions of the angled plate. Connection means for securing the energy absorber to a horizontal lifeline system are provided at one remote end of the folded plate. The connecting means are comprised of two opposing outwardly projecting upper flange portions situate at one remote end of the folded plate. Each flange portion has means for receiving connecting devices of the horizontal lifeline system.

[0010] In one embodiment of the invention, the non-elastic plate is made of stainless steel. The connecting fasteners are rivets and also made of stainless steel. The energy absorber of the present invention may optionally be coated with polymer coatings.

[0011] In use, the flange portions of the energy absorber are conventionally secured by respective carabiners or quick links, so as to operatively interpose the energy absorber between an anchorage point for the horizontal lifeline system and a horizontal lifeline.

04-056CA.specl .inc

[0012] The horizontal lifeline system includes one or more mobile attachment devices that the worker attaches to with a safety line. The mobile attachment devices move freely along the lifeline including past the intermediary supports.

[0013] In a fall situation, the opposing flanges of the energy absorber followed by the folded adjoining plate walls begin to be drawn apart by the load of the falling worker. As force is continually applied, the rivets connecting the adjoining plate walls start to deform and pull apart and eventually break. This action by the rivets effectively retards or dampens the rate at which the adjoining plate walls of the energy absorber are drawn apart, thereby reducing the maximum arrest force exerted on the falling worker, and decreasing loads on the anchorage.

[0014] Other advantages, features and characteristics of the present invention, as well as methods of operation and functions of the related elements of the structure, and the combination of parts and economies of manufacture, will become more apparent upon consideration of the following accompanying drawings, the latter of which is briefly described hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present invention may be further understood by reference to the following detailed description of the embodiments of the invention, taken in conjunction with the accompanying drawings, in which:

[0016] Figure 1 is an elevational perspective view of a section of a ceiling mounted horizontal lifeline system showing use of 'the energy absorber of the present invention.

[0017] Figure 2 is an elevational perspective view of a wall mounted horizontal lifeline system showing use of the energy absorber of the present invention.

[0018] Figure 3 is a perspective view of the energy absorber of the present invention situate in a horizontal lifeline system secured to a fall arrest roof anchor.

04-056CA.spec1,inc

(0019] Figure 4 is a view of the elongated folded plate portion of the energy absorber of the present invention without the fasteners.

(0020] Figure 5 is a view of the elongated folded plate of the energy absorber of the present invention showing where the fasteners will be applied.

(0021] Figure 6 is the energy absorber of the present invention.

(0022] Figure 7 is a view of the energy absorber of the present invention in a 7 0 deformed state after a fall situation.

(0023] Although the above description and accompanying drawings relate to specific preferred embodiments of the present invention as presently contemplated by the inventor, it will be understood that various changes, modifications and adaptations may be made without departing from the spirit of the invention.