EP1253280B1 - Device for a safety anchor - Google Patents

Description

The present invention relates to a mounting carriage to be installed on a profiled element acting as a rail, more particularly a vertical rail for example secured to a ladder.

It is essential to ensure total safety for people climbing on high height ladders by allowing the use of a reliable and mobile anchorage point, for a fastening element for example a carabiner.

Ideally the device should be able to be installed on existing ladders and allow the per person to use it to go up and down safely. This equipment should also be suitable for use by several people simultaneously on the same installation.

According to the invention, a fall arrest anchor carriage is thus proposed, sliding along a rigid vertical rail so as to be able to follow the location of a user moving vertically, for example along a ladder, which is attach to it for example with a carabiner.

We already know such devices. So the patent document US 3,348,632 discloses a safety carriage moving along a rail provided with a braking cam with an anchor point and a pivotable claw for braking the carriage by friction with an amount.

The patent document US 4,085,818 a trolley with a rail, the rail is made of reinforced plastic in which the cam can penetrate. However, this penetration produces a reversible deformation and therefore does not effectively lock the carriage, especially in case of rebound.

The invention proposes in particular to remedy this drawback. More specifically, the invention relates to a device consisting of a trolley with wheels and a rail along which said carriage can move, the rail being placed on a vertical support, said carriage being provided with a braking cam mounted on an axis with a spring, and having at the outer end of said cam an anchor point and at the opposite end a claw adapted to pivot and rub against a flat of said rail and thus block the carriage, when a force to the bottom is abruptly applied to the anchor point. The device is characterized in that the carriage is made of hard metal and the metal rail is softer and in that said claw is leveraged to penetrate substantially into the softer metal during said locking with braking.

According to a first aspect of the invention there is therefore provided a device comprising a trolley with wheels sliding vertically on a rail and provided with a brake cam with an axis and a spring. The carriage is made of steel, for example stainless steel and is preferably cut in the mass. The parts are preferably chemically treated to ensure good sliding between the moving parts and to avoid any corrosion. The brake cam is provided with a notch at one end for introducing a fastening or anchoring means such as a carabiner which links it directly or indirectly to the user, and a braking claw at the other end. .

The rigid belay support is an extruded aluminum safety rail that is placed on a vertical support, the carriage is placed on the flat T-shaped aluminum safety rail so that it can not be detach only by one end. The user equipped with a harness connects for example with a carabiner attached to his harness (with sternal anti-fall arrest loop) at the end of the brake cam of the carriage provided with said anchor point.

When the carriage is placed on the flat side of the rail and there is no manipulation, it remains blocked. The brake cam is not in tension, it is locked by the lever on the rail with a spring located at the inside of the cam. When the user climbs up or down along the rail, the truck moves automatically. Indeed, the positioning of the person during the ascent and descent generates a tension on the brake cam. The carriage can move smoothly as one moves along the rail. During the climb, the user drives the truck. During the descent the carriage slides freely under the effect of a slight horizontal pull that is obtained by the natural position of the body of the user.

According to a feature of the invention, in the event of a fall, the steel brake cam locks on the aluminum rail by a lever effect. As the forces generated by a fall are very high, the claw of the steel brake cam crushes and penetrates the softer aluminum (eg F22 grade). A stop is provided to prevent the cam from tipping over the penetration thickness of the cam in the aluminum.

This principle of crushing aluminum allows a smooth braking and a significant absorption of the fall forces and thus limits the bodily injury of a user.

The results of the measurements of braking forces measured during a mass drop of 100 kg are less than 6 kN as required by the standard regulating this type of equipment. The use of a steel rail would not allow this braking characteristic and would require the use of a complementary energy absorption system (spring etc ..).

It will be understood that the ends of the beginning and the end of the rail installation as well as any possible interruption must be secured to prevent untimely release of the carriage.

To this end, it is possible to provide step stops with a pivotable flap. These stops are made of anodized aluminum, with a self-closing valve preventing untimely exit of the truck (a voluntary operation is necessary) and two polarizers placed asymmetrically to avoid placing the truck upside down.

The rail used with the trolley of the invention is preferably a profile provided with a plate on which the carriage runs. It will be for example aluminum AlMgSi0.5 extruded. On the opposite side a slide is integrated in the rail to accommodate bolt heads component fixing which supports the rail. The fixings are separated from 1 to 2 meters maximum.

In known manner, each joint rail ends is provided with 2 junction plates (fishplates) provided with 4 holes each and 4 bolts. One dish is placed in the slide (tapped hole) and another on the outside (unthreaded holes). These bolts in the holes allow a connection of the rails to each other, ensuring proper alignment, and withstanding a pulling width of up to 1,500 kg as required by standards regulating this kind of equipment.

The ladders may also be of the angle type, such as those used to access the top of lattice-type power transmission towers. It is then an angle provided with bolts of a length of +/- 15 cm which are fixed on the wings of this angle and serve as steps. During the ascent or descent, people can be secured against falls also by a device according to the invention. As above, this is an aluminum T-rail and a fall-prevention trolley that slides on this aluminum T-rail.

According to another aspect of the invention, which may be dependent or independent of the above-mentioned carriage, a Y-fastening device is proposed in order to fix said rail on an angle. If this fixing was to be made of steel, it should be welded in 4 places and in line, which leads to a significant manufacturing time and less reliability due to welding.

The invention therefore proposes a profiled element in Y, Y whose vertical branch comprises a horizontal foot. The element is made of aluminum and can be extruded, cut and drilled, the opening of the arms of the Y adapting to the angle forming the ladder, and the flat foot extending from a distance of one side beyond Y, distance or section where a perforation is provided for the passage of a screw or nut to be fixed to the aforementioned safety rail. The vertical branch plate of the Y also has a hole to accommodate a stud. When tightening the nuts of the thrust bearings, the flange completely blocks 1 aluminum fastener on the angle.

Advantageously, it is possible to provide a recessed rounding situated inside the angle of the arms which facilitates the placement and blocking of the part, in particular in case the edge of the angle is damaged or covered by an excess of galvanization that causes balls.

The offset of the flat where the bolt supporting the T-rail is fixed is calculated so that the movement of the operators on these ladders is the best and also so that there is sufficient space for the clamping nuts and the fingers installers.

The invention will be better understood on examining the accompanying drawings, provided solely by way of non-limiting example.

• les figs. 1a et 1b sont des représentations du chariot et du rail selon l'invention vu respectivement de côté (A) et en section transversale (B),
• la fig. 2 est une vue d'un rail pour le chariot, fixé au montant d'une échelle de deux manières
• les fig. 3a à 3c représentent un rail fixé au milieu des échelons d'une échelle, et illustre une jonction de deux rails,
• les figs. 4a et 4b représentent plus en détail une jonction de deux rails,
• la fig. 5 illustre en perspective un rail de sécurité pour un chariot selon l'invention
• la fig. 6a à 6c illustrent le fonctionnement des butée en aluminium, aux extrémités inférieures et supérieures des rails,
• la fig. 7 représente un profilé de fixation du rail sur une échelle en cornière,
• les fig. 8a et 8b représentent schématiquement en section transversale et en élévation la fixation d'un rail au profilé de la fig. 7 ,
• la fig. 9 représente une vue en élévation de la cornière avec échelons et le dispositif de fixation du rail à cette dernière.

In these drawings:

• the Figs. 1a and 1b are representations of the carriage and the rail according to the invention seen respectively on the side (A) and in cross section (B),
• the Fig. 2 is a view of a rail for the trolley, fixed to the amount of a ladder in two ways
• the Fig. 3a to 3c represent a rail fixed in the middle of the rungs of a ladder, and illustrates a junction of two rails,
• the Figs. 4a and 4b represent in more detail a junction of two rails,
• the Fig. 5 illustrates in perspective a safety rail for a carriage according to the invention
• the Fig. 6a to 6c illustrate the operation of the aluminum stops, at the lower and upper ends of the rails,
• the Fig. 7 represents a profile for fixing the rail on an angle ladder,
• the Fig. 8a and 8b schematically represent in cross section and in elevation the fixing of a rail to the profile of the Fig. 7 ,
• the Fig. 9 represents an elevational view of the angle iron with rungs and the device for fixing the rail to the latter.

The Fig. 1 is a representation of the carriage 1 according to the invention seen from side (A) and seen in section from above (B). There is a carriage body 2 comprising hollow rollers 3 moving on a flat 14 of a vertical rail 10. A cam 9 can tilt about an axis 5 of the body 2 and comprises at one end an attachment point 4 and at the other end a claw 7 in contact, by action of a spring 6, with the material of the plate 14 of the rail. It is understood that a sudden downward force (arrow) of the attachment point 4 causes a tilting of the claw that penetrates into the material of the plate causing braking and the desired anti-fall effect. A stop 8 prevents tilting of the claw of the cam 9 beyond the thickness of material.

The Fig. 2 is a view of a rail for the carriage 1, attached to the post 22 of a ladder in two ways. Is provided either a fastener 20 enclosing the upright 22 or a fastener 21 attached with the end of a step 23. The rail is held by bolts inserted into a slide 11 provided in the rail, opposite the flat slide 14 of the carriage 10.

The Fig. 3 represents a rail 10 fixed in the middle of the ladders 23 of a ladder by fastening elements 29, and illustrates a junction of two rails (10a and 10b). Detail C shows the two fishplates 12 and 12 'on either side of the slide 11 clamped by bolts 13.

The Fig. 4 shows in greater detail, in elevation and in plan, a particular mode of joining two rails 10a 10b in which bolts 30 are inserted into holes 16 of the inner wall of the slide 17, also enclosing ribs 12 and 12 ' .

The Fig. 5 illustrates in perspective a safety rail 10 for a carriage 1 according to the invention. We distinguish the holes 16 in the inner wall 17 of the slide 11.

The Fig. 6 illustrates the operation of the stops (40 'and 40) made of aluminum, respectively at the lower ends (B) and upper (A) of the rails allowing the passage of the carriage 1 in one direction only, without the express manipulation of the user. Detail C illustrates an upper rail section with a stop 40 and polarizers 19 not allowing to slide the carriage in the right orientation, a complementary groove being provided in the carriage.

The Fig. 7 represents a profile 50 Y fixing of the rail on an angle ladder. The foot of the Y has a flat which extends at 51 beyond the vertical leg and comprises in this part a hole 52. The intersection of the arms or wings (54, 55) of the Y intended to grip an angle iron has a rounded forming a receiving channel of the edge of the angle.

The Fig. 8a represents a cross section and the Fig. 8b partially in elevation the attachment of a rail 10 to the profile 50 of the Fig. 7 and at the angle 60. There are the bolts 66 and the studs 65 which clamp the thrust bearings 68 on the wings 54 and 55 of the angle 60. The attachment of the part 50 to the rail 10 is illustrated in elevation. The hole 52 of the section 51 of the piece receiving a bolt 58 whose head is located in the slide 11 of the rail 10.

The fig 9 schematically shows in perspective an angled ladder section 60 comprising two perpendicular rungs 61 and a rail attachment system 50 (not shown). The fixing profile 50 of the rail covering the edge of the angle iron is recognized with the elements equivalent to those described in FIGS. Figs. 8a and 8b , in particular the flange 65 and the hole 52 for attachment to the safety rail.

Claims (10)

1. Assembly comprising a carriage (1) with rollers and a rail (10) along which said carriage is capable to move, the rail being located on a vertical support, said carriage being provided with a braking cam (9) mounted on an axis (5) with a spring (6) and comprising at the external end of said cam an anchoring point (4) and at the opposite end a claw (7) able to pivot and rub against a flat (14) of said rail (10) in order to lock the carriage (1), when a downward force is suddenly applied on the anchoring point (4) characterised in that
   the carriage (1) is made of hard metal and the rail (10) is made of a softer metal and in that the claw (7) is able by lever effect to penetrate substantially in the soft metal in case of locking with braking.
2. Assembly according to claim 1 wherein the cam (9) is made of stainless steel.
3. Assembly according to any of the preceding claims
   characterised in that the rail (10) is made of aluminum, preferably anodized aluminum.
4. Assembly according to any preceding claims
   characterised in that the carriage comprise a body (2), a braking cam (9) with an axis (5) and a spring (6), and 4 guiding rollers (3) with 4 spindles fixed to the body by crimping, and cannot be opened.
5. Assembly according to any preceding claims wherein the rail (10) is vertical.
6. Assembly according to any preceding claims
   characterised in that the rail is fixed on a ladder.
7. Assembly according to any preceding claims
   characterised in that the rail is fixed on an upright (22) of a ladder with fastening elements (20, 21).
8. Assembly according to any preceding claims
   characterised in that the rail is fixed on rungs (23) of a ladder with fastening elements (29).
9. Assembly according to any preceding claims
   characterised in that the carriage comprises a slot for the passage of a foolproof extension (19) provided as a stop at least at one end of the rail (10).
10. Assembly according to any preceding claims wherein there are several carriages (1) for a single rail (10).

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