DK178036B1

DK178036B1 - Faldsikring

Info

Publication number: DK178036B1
Application number: DK201370784A
Authority: DK
Inventors: Martin Thomsen
Original assignee: Jual Holding As
Priority date: 2013-12-17
Filing date: 2013-12-17
Publication date: 2015-04-07
Also published as: WO2015091367A1; EP3082979A1

Description

A fall restraint

The present invention relates to a safety device such as a roof anchor for personal fall restraint or fall arrester. The roof anchor includes anchoring means configured for receiving a lanyard interconnecting a person, via a safety harness and the roof anchor, to a surface or underlying structure. By this, a potentially lethal fall of a workman from a substantial height is prevented.

According to a first aspect, the present invention relates to a shock absorbing roof anchor for a fall restraint. The roof anchor includes: - an energy absorbing base part configured to be coupled to a surface or underlying structure, and - lanyard anchor means which could constitute an eyebolt. The anchor means is configured to connect a lanyard to the energy absorbing base part.

To arrest a workman's fall from an elevated surface in a controlled and non hazardous manner, it is essential that there is sufficient energy absorption capacity built into the fall arresting system. Without built-in energy absorption, the fall of the person can only be arrested by applying large and abrupt forces to the person. The forces may easily reach a level which can result in severe injuries to the person being arrested by the system.

The most common fall arrest system is the lifeline system. The system includes a rope or lanyard which interconnects a roof anchor with a user's safety-harness.

The rope or lanyard can be a lifeline which stretches to lengthen the fall distance as it absorbs some of the energy.

Background A shock absorbing roof anchor for a fall restraint of the type as described in the opening paragraphs is finding increasingly application, particularly on roofs of houses and buildings, as fastening point for a fall protection.

The shock absorbing roof anchor for a fall restraint of the type according to the present invention is first and foremost a result of the increasingly stringent regulations in respect of fall protection while work is carried out on roof tops and the like. A safety device such as a roof anchor for a fall restraint usually comprises a base from which a fastening eye or other anchoring member extends and which is permanently fixed to the object. An example of such a safety device is known from US 5,287,944. The safety device described therein is fastened to the fixed construction of the object by means of a large number of screws and plugs. A corresponding number of holes are drilled for this purpose into the construction of the object at the set position. In this known safety device the fixing eyelet is formed as an integral part with the base.

Another example of a similar fall restraint is known from US 5,687,535.

The abovementioned two fall restraints offer solid and reliable anchor points for fall protections; they also, however, have considerable drawbacks. Owing to the rigid structure of the fall restraints, the energy of a possible fall is not absorbed by the structure and thereby the kinetic energy resulting from the fall has to be absorbed almost wholly by the falling person. US 2007/0144830 A discloses a fall restraint including an energy absorbing anchoring member. The anchor member constitutes a flexible floppy flap which extends substantially laterally from the anchor point of the device and which is adapted to be connected to, or be unified with, the surrounding surface or roof to bring about a durable connection with same. According to the disclosure, the fall restraint further includes opposed flange like bodies accommodating in-between them a central portion of the flexible floppy flap.

The flanges are configured to distribute any forces imposed on the anchor point of the fall restraint to a large area of the flexible floppy flap. The flexible floppy flap may constitute a piece of bituminous roof covering or equivalent and the flexible floppy flap may be unified with the surrounding surface by means of heat bonding or gluing etc. It is clear from the disclosure that, in case of fall of a worker, the forces are to be transferred to the roof by conveying the energy from the fall through the flexible floppy flap via the bond and then onto the roof covering material, this without interconnecting the force transferring flexible floppy flap with the roof's underlying structure. Accordingly, a fall restraint may be provided on a surface such as a roof top without compromising the integrity or tightness of the surface carrying the fall restraint. The strength or capacity of the fall restraint according to US 2007/0144830 A is, as a consequence of the on-face installation, limited to the weaker of the flexible floppy flap, the integrity of the bond and to the strength of the surrounding surface such as the surrounding roof covering material. EP2216466A1 discloses a fall protection for installation on the roof of a building. This fall protection has: - a thin-walled, hollow deformation part (30) bearing on the roof; - an anchor point (9) mounted on top of the top of the deformation part (30); - a fastener (107) that is fixed to the bearing substructure; - a tensile member (114) that substantially centrally inside the deformation part extends downward and is mounted so that the external force exerted to the anchor point is transferred to the fastener through the tensile member.

Brief description of the invention

The object of the present invention is to provide a fall restraint configured to: - dampen the peak decelerating forces imposed on a person in case the person falls, - provide maximum retaining force; the retaining force should not be limited to the integrity of a bond or to the adherence to the surrounding surface of an underlying surface, - not compromise tightness of the surface even when the fall restraint is rigidly connected to the underlying roof, and - allow for fast and easy installation

The above objects are met by the provision of a fall restraint according to the introductory part of this specification wherein the fall restraint further includes a sheet of flexible covering material connected to the base part. The sheet of flexible covering material is configured to partially encase the base part to define upwards closure of a cavity which, together with a surrounding surface, accommodates the energy absorbing base part when the shock absorbing roof anchor is mounted on or onto a surface. The sheet of flexible covering material may be connected to the base part by means of the anchor fittings. The anchor fittings may extend through the flexible covering material and the base part in one or both of the essentially central portions of one or both of the flexible covering material and the base part. Further, the anchor fittings may bring together the roof anchor under a threaded connection.

The sheet of flexible covering material is, in accordance with the present invention, configured to comply with deflections of the base part in response to energy absorption by the base part without significantly taking up forces from the from the fall.

According to one embodiment, the outer periphery of the sheet of flexible covering material may extend beyond the outer periphery, or the legs, of base part. The outer periphery may further be configured to connect to, or with, the surface surrounding the base part.

According to one embodiment, the fittings may be configured to receive, possibly in internal threads, an anchor member such as a hook or an eyebolt.

According to one embodiment, the fittings may constitute a nut disposed inside the base part, or inside a cavity or hollow defined by the base part, and a screw disposed on the outer and upper surface of the sheet of flexible covering material.

According to one embodiment, a cover support flange may be disposed in-between the base part and the sheet of flexible covering material. The support flange may be configured to guide or support the sheet of flexible covering material in the area above the base part. The flange may be connected to, or be integrated with, the sheet of flexible covering material.

According to one embodiment, the sheet of flexible covering material may constitute a sheet of bituminous roof covering. By this, easy connection, integration or bonding to a surrounding surface of bituminous roof covering may be obtained.

According to one embodiment, the base part may comprise at least three legs configured to, at their outer ends; connect to a surface, such as a roof,

According to one embodiment, the two strips may be oriented essentially perpendicular to each other.

According to one embodiment, the legs may be joined in a central portion of the base part by fittings interconnecting the lanyard anchor means to the base part.

According to one embodiment, each of the legs may include energy absorbing zones configured to lengthen response shock loading imposed on said anchor means.

Brief description of the drawing

Figure 1 shows a principal side view of a fall restraint according to an aspect of the present invention.

Figure 2 shows a principal bottom view of a fall restraint according to an aspect of the present invention.

Figure 3 shows in perspective the top face of a fall restraint according to an aspect of the present invention.

Figure 4 shows a principal side view of a fall restraint according to an aspect of the present invention where the fall restraint is mounted on a surface.

Figure 5 shows a principal side view of a fall restraint according to an aspect of the present invention where the fall restraint is mounted on a soft roof.

Detailed description with reference to the figures

The invention will now be further described with reference to the figures and on basis of exemplary embodiments.

The figures are purely schematic and not drawn to scale. Some dimensions or parts may be exaggerated to a greater or lesser extent for the sake of clarity. Corresponding parts are designated as far as possible in the figures with the same reference numeral.

Figures 1 - 5 show one embodiment of a roof anchor 1 for a fall protection according to the invention.

The roof anchor comprises a base part 5 having one or more surface contacting or surface engaging feets. The feets may be provided with through holes configured to receive screws or bolts 80 fixing the base part 5 to an underlying structure 55; possibly though insulation material 90 as shown in figure 5. Preferable, the means for fixing the base part 5 to the underlying structure may be configured to connect to construction elements, or strength members 55, of the surface 50 carrying the roof anchor 1.

Examples of strength members are roof rafters 55 or concrete roof decks.

The surface 50 may constitute a rooftop or a vertical building face and the like.

The base part 5 may, as mentioned in the introductory part of this specification, be connected to lanyard anchor means 10. In the depicted embodiment, the lanyard anchor means 10 constitute an eyebolt 10.

In use, a not shown safety line of a fall arrest harness is secured to the fixing eyelet 10 extending from the base part 5. The connection may for instance be accomplished by means of a not shown karabiner hook or snap hook.

In accordance with the invention, the shock absorbing roof anchor 1 further includes a sheet of flexible covering material 20. The sheet 20 may be connected to the base part 5 via anchor fittings 11, 12 via a through hole arranged in the sheet of flexible covering material 20.

The sheet of flexible covering material 20 may be configured to encase, or surround, the base part 5 when the shock absorbing roof anchor 1 is mounted on a surface 50 such as a roof and the like. By this, and together with the surface 50, one or more cavities 30 are defined.

As can be seen in figure 5, the base part 5 may be arranged on so-called warm roofs, or soft roofs, where the roofing membrane 50 is arranged on top of resilient insulation material 90. When the roof anchor 1 is installed on warm roofs it may be desired to provide cut-outs 91, or pockets, configured for accommodating at least partially the feets and/or the bends 6. The cutouts 91 may or may not extend through the insulation material 90. A warm roof is a type of roof construction which has an insulation layer above the structural members such as rafters or concrete decks, and immediately below its weatherproof membrane. A warm roof construction has many benefits over a traditional 'cold roof, essentially it is a 'breathable roof construction', which allows moisture to escape which in turn prevents damp and any associated decay problems. A warm roof construction allows heat to be conserved within a property - without the need for a ventilation system.

The sheet of flexible covering material 20 may be connected to a central portion of the base part 5. Further, the sheet of flexible covering material 20 may be centralised, or co aligned, with the central part of the base part 5.

The fittings connecting the sheet of flexible roof covering material 20 to the base part 5 may constitute a nut 12 and a threaded screw section 11. The threaded screw section 11 may be provided with flange means 13 configured for securing tightness between the sheet 20 and the threaded screw section 11.

The sheet of flexible roof covering material 20 may be configured to extend laterally from a central portion of the base part 5 and beyond any energy absorbing means 6 disposed in or on the base part 5 such that the base part 5 including any energy absorbing means 6 is enclosed completely by the surface 50 carrying the roof anchor 1 and the sheet of flexible roof covering material. 20.

The periphery of the sheet of flexible roof covering material 20 may, at its underside, be provided with a border or rim 22, such as shown in figure 2. The border or rim 22 may be configured for bonding with the surface 50 to which the roof anchor 1 is attached. The bonding may take place by means of application of heat, gluing or by means of rigid attachment members such as screws or nails etc.

The sheet of flexible roof covering material 20 may constitute a sheet of bituminous or plastic roof-covering material or equivalent. The material chosen may be configured for fusing or gluing, at an increased temperature or not, to a similar covering material.

In the shown embodiment, the sheet of flexible roof covering material 20 extends around the other portion of the base part 5. The sheet of flexible roof covering material 20 may constitute a square sheet. The sheet of flexible roof covering material 20 may however equally be embodied as rectangular or round without departing from the present invention.

The base part 5 constitutes a base configured for transmitting loads from the lanyard anchor means 10,11 to the surface 50 or structure to which the roof anchor 1 is mounted or connected. The base part 5 may be configured such that the base part 5 will not deflect, or deflect plastically, in response to low loads.

According to one set of regulations, the base part 5 shall be configured such that the anchor means 10, 11 is moved less than 10 mm by way of plastically deformation of the base part 5 in response to forces of 0,7 kN applied to the anchor means 10, 11.

If greater force is applied to the base part 5 via the lanyard anchor means 10, 11, and it the forces are oriented approximately parallel to the bottom plane of the base part 5, the base part 5 will deflect significantly and thereby lengthen the effective stopping distance of a person falling. The base part 5 may be embodied in various ways to obtain this property however it is considered that the base part 5 according to the depicted embodiment is particularly beneficial as the base part 5 on one hand is easy and cheap to produce and, on the other hand, demonstrates satisfactory energy absorbing properties.

The depicted legs 5 are provided with bends 6 or equivalent configured to unbend or twist in response to forces applied to the anchor means 10,11. The bends 6 may unbend or twist under plastic deformation.

As can be seen in figure 2, all four legs 5' of the base part 5 may be provided with bends 6. As the four legs 5' are rigidly connected to each other via the fittings 11, 12, which equally could constitute welds or rivets etc., all four bends 6 may facilitate dampening of the person falling. In this context, the skilled reader will realize that at least one bend 6 may at least partially unbend in response to deflection of the base part 5 while the remaining legs 5' may twist etc.

Further, the skilled reader will realize that the entire base part 5 incl. the flexible covering material 20 will deform significantly in the event a person is arrested in a fall. As a consequence, the fall restraint may require replacement.

Arrangement or provision of roof anchor 1 on, for instance, a flat roof 50 provided with a bituminous roof covering, can be carried out simply and quickly with no effect on the integrity of the original roof-covering as the sheet of flexible roof covering material 20 may integrate with the surrounding roof under a heat bonding process.

The invention has been described above on basis of only one exemplary embodiment. It will be apparent that the invention is by no means limited to this embodiment. On the contrary, many variations and embodiments are still possible within the scope of the invention for a person with ordinary skill in the art.

The different embodiments of the safety device for fall protection according to the invention have in common that they are lightweight and can be mounted rapidly with simple means and tools.

Claims

1. Stødabsorberende taganker (1) til en faldsikring, hvilket taganker (1) indbefatter: - en energiabsorberende basisdel (5) som er udformet til at blive koblet med en underliggende struktur (55), og - sikkerhedslineankerelementer (10), (11), som er udformet til at forbinde sikkerhedslinen med den energiabsorberende basisdel (5), hvor den energiabsorberende basisdel (5) er udformet til at afbøje plastisk som reaktion på en stødbelastning, der påføres sikkerhedsankerelementet (10), hvor det stødabsorberende taganker (1) desuden indbefatter en plade af et fleksibelt afdækningsmateriale (20) forbundet med basisdelen (5), og at pladen af fleksibelt afdækningsmateriale (20) er udformet til delvist at indelukke basisdelen (5) for at definere en opadgående lukning af et hulrum (30), der sammen med en omgivende overflade (50) optager den energiabsorberende basisdel (5), når det stødabsorberende taganker (1) er monteret på en overflade (50), kendetegnet ved, at pladen af et fleksibelt afdækningsmateriale (20) er forbundet med basisdelen (5) ved hjælp af ankerfittings (11), (12) der strækker sig gennem det fleksible afdækningsmateriale (20) og basisdelen (5) i i det væsentlige centrale afsnit af det fleksible afdækningsmateriale (20) og basisdelen (5).

2. Stødabsorberende taganker ifølge krav 1, hvor den udvendige omkreds af pladen af det fleksible afdækningsmateriale (20) strækker sig ud over den udvendige omkreds af basisdelen (5), og hvor den udvendige omkreds er udformet til at forbindes med overfladen (50), der omgiver basisdelen (5).

3. Stødabsorberende taganker ifølge et eller flere af de foregående krav, hvor fittingsene (11), (12) er udformet til at samle tagankeret (1) ved hjælp af en gevindforbindelse.

4. Stødabsorberende taganker ifølge et eller flere af de foregående krav, hvor fittingsene (11), (12) er udformet til at modtage et ankerelement (10).

5. Stødabsorberende taganker ifølge krav 4, hvor fittingsene (11), (12) danner en not (12) eller tilsvarende anbragt inden i basisdelen (5) og en skrue (11), der er anbragt på den udvendige og øvre overflade af pladen af det fleksible afdækningsmateriale (20).

6. Stødabsorberende taganker ifølge et eller flere af de foregående krav, hvor en afdækningsstøtteflange (21) er anbragt mellem basisdelen (5) og pladen af det fleksible afdækningsmateriale (20).

7. Stødabsorberende taganker ifølge et eller flere af de foregående krav, hvor pladen af det fleksible afdækningsmateriale (20) danner en plade af en bituminøs tagafdækning.

8. Stødabsorberende taganker ifølge et eller flere af de foregående krav, hvor basisdelen (5) omfatter mindst tre ben (5’), som ved deres udvendige ender er udformet til at forbindes med en overflade (50) og til at være indbyrdes forbundet med hinanden for at definere et centralt afsnit af basisdelen (5).

9. Stødabsorberende taganker ifølge krav 8, hvor benene (5’) er forsynet med en eller flere buer (6), som er udformet til i det mindste delvist at rette ud som reaktion på stødbelastningen, der påføres sikkerhedslineankerelemen-terne (10), (11).

10. Stødabsorberende taganker ifølge krav 8 eller 9, hvor basisdelen (5) omfatter fire ben (5’), som er defineret af to metalstrimler, og hvor de to strimler overlapper hinanden i det væsentlige i midten af strimlerne.

11. Stødabsorberende taganker ifølge et eller flere af kravene 8-10, hvor de to strimler er orienteret vinkelret på hinanden.

12. Stødabsorberende taganker ifølge et eller flere af kravene 8-11, hvor benene (5’) er samlet i et centralt afsnit af basisdelen (5) ved hjælp af fittings (11), (12), der forbinder sikkerhedslineankerelementet (10) med basisdelen (5).

13. Stødabsorberende taganker ifølge et eller flere af kravene 8-12, hvor hvert af benene (5’) indbefatter energiabsorberende områder, som er udformet til at forlænge reaktionen på stødbelastningen, der påføres ankerelementerne.