Note: Descriptions are shown in the official language in which they were submitted.
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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
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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.
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[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.
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(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.
