EP0402214A1 - Safety device for the access to a ladder from an upper floor - Google Patents

Abstract

The safety system is used for guarding the access to a ladder (3) which enables a person to descend from an upper floor (1) to a lower one or from a point at ground level to a second point some distance below, consists of a trap-door guarding the top of the ladder and a cage (8) round the ladder's upper end. Beneath the cage is a platform (5) which can be moved from a position immediately beneath the cage to one in which it allows access to the ladder. The platform has a foot pedal (9a) to release its lock and move it horizontally along a frame (6) between its two positions. The ladder can also incorporate a vertical guide bar (4) for a safety harness slider.

Description

The present invention relates to the field of industrial security, in particular the security of people when they use ladders.

When a ladder reaches a certain height (generally more than 3 meters) it must include a device to prevent vertical falls. One of these devices consists of a rail located at the center of the ladder along which a trolley can slide, this trolley being connected to a harness worn by the user, jamming in the rail during a fall.

Another protective device is the provision of a cage (or crinoline) surrounding the ladder.

While access to these ladders in the direction of their ascent from a lower floor does not present any danger, their access in the direction of descent from a higher floor presents several risks.

First of all as far as the user is concerned, placing yourself above the vacuum before any safety operation, access to the ladder being discovered from a hatch in the floor, is a first risk.

Then, with regard to the protection of users of the upper floor, the open hatch constitutes a danger against which it is necessary to protect them.

To provide a solution to these problems, the invention relates to a device for protecting access to a ladder from an upper floor which comprises a platform movable between a first position close to the ladder and a second position remote therefrom, and a railing extending above the level of the platform.

In addition, this platform includes maneuvering means for moving it from the first to the second position, arranged on each of its lower and upper faces, and a return member. automatic from its second to its first position.

Two cases may arise. The first, relatively rare, is that in which the ladder has an access end which extends above the upper floor. In this case, the platform is at the level of this floor and the railing can be constituted by a portion of the railing of the floor, in particular if the latter is a circulation bridge along a vertical wall. It is understood in this case that the user can place himself on the ladder in complete safety before retracting the platform to begin to descend.

The second case, the most frequent and most dangerous, is that in which the ladder does not exceed the level of the floor. Under these conditions, the platform is located under the floor and the railing extends between the floor and the platform.

The height separating the platform from the floor is of the order of two meters.

It is mainly in this scenario that it is necessary to ensure the safety of users of the platform, in addition to that of the user of the ladder.

To do this, the platform includes means for locking it in its first position.

Thus applied to crinoline ladders, the device comprises, at the upper floor, a ladder access hatch and means for unlocking the platform cooperating with the hatch when the latter is in its closed position. access to the ladder.

Under these conditions, the user of the ladder can only descend after having closed the access opening made in the floor.

Applied to ladders provided with a rail or an anti-fall slide to receive a slide connected to a harness covered by the user, the device comprises, at the level of the upper floor, a hatch for uncovering and closing the access to the ladder, means for unlocking the platform cooperating with the hatch when the latter is in its closed position for access to the ladder and with the slide during from its introduction into the fall prevention rail.

With such ladders, securing the user of the ladder requires an action by the user consisting in putting his safety harness into service. The authorization to descend, by unlocking the platform is therefore conditioned on the one hand to the accomplishment of this operation and on the other hand to the closing of the hatch, this to ensure the safety of the users of the upper floor.

In an alternative embodiment also applied to ladders provided with a rail or an anti-fall slide intended to receive a slide connected to a harness covered by the user, at least part of the railing can be moved from a first position located above the platform and below the level of the floor to a second position where it is located at least partially, above the floor. In this case, the means for unlocking the platform cooperate with the railing when the latter is in its second position and with the slide when it is inserted into the fall prevention rail, to obtain the same conditions in this case. which concerns the security to be obtained.

Finally, it is also necessary to take into account the case where access to a ladder from an upper floor is subject to access regulations. Such an arrangement can only be achieved by means of a door for locking access. In a preferred embodiment, the hatch is with a sliding panel in a floor structure which comprises maneuvering means on each of its faces, automatic return means in its closed position and locking means, the means of recall and lock comprising a bolt carried by the horizontal sliding panel associated with a vertical control rod terminated in the lower part by a handle to pull it down, which constitutes one of the means for operating the panel and cooperating in the upper part with a depressing pedal of the rod which constitutes the other means of operating the panel.

To avoid inadvertent operation of the hatch by inadvertently pressing the pedal, the latter is mounted to slide vertically in the panel and to rotate relative to this panel, angular indexing means being provided between the pedal and the panel. to allow the pedal to be depressed only in a determined angular position of the latter relative to the panel, an elastic return member being coupled between the pedal and the panel to move the pedal away from this position.

The access to any unauthorized person is condemned by means of blocking the pedal in the high position, associated with a lock accessible by the upper face of the panel.

The invention will be better understood during the description given below of some exemplary embodiments which will make it possible to identify the advantages and other characteristics thereof.

• - la figure 1 est une vue extérieure d'un premier mode de réalisation de l'invention,
• - la figure 2 est une vue en élévation d'une variante de la figure 1 dans laquelle le garde-corps est mobile,
• - les figures 3 et 4 illustrent des détails d'une trappe d'obturation de l'ouverture d'accès ménagée dans le plancher supérieur.

Reference will be made to the appended drawings in which:

• FIG. 1 is an external view of a first embodiment of the invention,
• FIG. 2 is an elevation view of a variant of FIG. 1 in which the railing is movable,
• - Figures 3 and 4 illustrate details of a shutter closing the access opening formed in the upper floor.

In the first two figures, the examples shown relate to ladders with anti-fall rails, which do not include portions rising above the floor. It is obvious that the elements described are easily transposable on the one hand to crinoline ladders and on the other hand to ladders having an extension above the floor for example when the latter is a walkway along a wall. In the latter case, the means of the invention, in particular the platform, are located at the same level of this floor.

At the level of a carriageway 1 or a sidewalk, there are openings, generally covered with plates such as 2, through which one can descend into the underground network of urban sewers or more generally of technical pipes. Similarly, in many industrial installations, such openings are made in floors or walkways to give passage to technical circulation corridors, access shafts, ducts, etc. These vertical conduits are generally equipped with ladder bars 3 which, to form a safety ladder, comprise a central rail 4 intended to receive a carriage which slides there (or rolls there) freely. This carriage comprises a coupling member for a lanyard which is fixed to a harness with which the user of the ladder is coated. The carriage, in known manner, has the option of stopping in the rail if the user falls.

The invention seeks to protect the user when the carriage is placed in the safety rail. There is provided for this purpose a platform 5 mounted on a horizontal frame 6 and able to move along this frame between a position where it is close to the scale and a position where it is spaced from the scale of a sufficient distance to allow the passage of a man between the ladder and the spread platform. A device 7 known in itself recalls the platform 5 in its first position with a time delay allowing sufficient time for the passage of the user both on the descent and on the ascent.

Finally, a railing 8 is disposed here of fixed way (for example by being sealed to some of the walls of the downpipe) to delimit a safety space around the ladder for a person standing on platform 4. The shape of this railing depends well heard from the vertical passage section. It will comprise at most three sides but may only consist of a barrier parallel to the wall carrying the ladder bars 3 if the side walls of the passage are close enough to one another.

By this device, the user of the ladder having put on the harness, can safely descend the few bars which lead to the platform (which will be for example between 1.50 and 2 meters under the roadway or the floor) . This descent is carried out inside the railing 8 and if there is a fall, it will be of low height and confined in this space internal to the railing. On the platform, the user connects the harness to the carriage present at the end of the rail 4. He then pushes the platform 5 backwards by acting on the foot on a pedal 9 a which has the following functions: 'on the one hand to unlock the platform and on the other hand, to constitute a support to exert the force necessary to repel it. The mechanisms linked to the pedal 9 a for ensuring the locking of the platform, for example to the chassis 6 in its first position, will not be described in detail. It can be a latch operated by the pedal against a return spring. It will also be mentioned that on its underside, the platform 5 has a handle 9 b (see FIG. 2) for unlocking the platform and moving it backwards. Thus the user going up the ladder clears the passage to access the exit. The user having passed under the platform, the latter is brought against the ladder by means of the return member 7. It will be noted that to reach the wall, the platform includes a notch 10 intended for the passage of the rail 4.

In this figure, there are also shown means for on the one hand forcing the user of the ladder to place themselves in a security situation and on the other hand for ensuring the safety of the users of the floor 1. The opening is closed by a panel 2 which can slide horizontally against a return device in the closed position, not shown. A locking device 22 is provided on one of the edges of this panel 2 and the latter engages automatically. A pedal 23 which will be shown in detail in FIGS. 3 and 4 makes it possible to open this panel. In the closed position, the panel 2 cooperates with a device 24 which is connected to a lock 25 for blocking the platform 5 in its first position close to the ladder. The members 24 and 25 are shown diagrammatically and can take many embodiments. Mention will be made, for example, of a cam of the device 24 which is actuated by the panel 2 and the movement of which is transmitted by a cable 26 in a sheath to a bolt which retracts.

In the same way, a device 27 is connected to the device 25 by a link 28. This device is operated when the carriage of the safety harness passes through the rail. Its movement can thus be transmitted to a second bolt that would include the device 25, which therefore retracts.

The platform 5 can be moved away from the ladder when the two bolts are retracted, which means that the user of the ladder is in a safe situation (connected to the rail 4) and that the hatch is closed. The safety of floor users is therefore also ensured.

In Figure 2 we find most of the elements already described with the same references. In the variant shown, the railing 8 is supported by the wall 11, where the bars 3 are located, by means of two slides 12 and 13 guided in slides vertical 14 and 15 fixed to this wall. The slides 12 and 13 are of sufficient length so that they still remain fully engaged in the slides 14 and 15 after an increase in the order of the height of the railing 8. The slides 12 and 13 are integral with the railing 8 by lateral structures 16 which will be calculated to provide the assembly with sufficient resistance. A device for balancing the weight of the railing and its slides is symbolized by the two counterweights 17 coupled to the railing 8 by cables 18 passing over pulleys also fixed to the wall 11. By this balancing, a user on platform 5 can easily lift the railing to make it come out above level N of the floor. The railing 8 then constitutes a protective barrier around the opening 2 for access to the vertical passage which remains open during the operations. Of course, this barrier has at most only 3 sides if the railing is of square section. It is nevertheless possible to provide on the fourth side an upper bar 20 always situated above the first bar, to which heavy elements (sheets of colored plastic material) 21 can be hung, to materialize the barrier for the view even if it is physically passable.

In a variant not shown, it can be provided that the railing is coupled to a mechanism allowing its automatic exit when the access hatch is opened (for example by the set of heavier counterweights than the railing itself). even). A mechanism for lowering this railing can be provided at the level of the platform 5 to be actuated by the user before he leaves the ladder in the direction of exit.

Locking members will also be provided along the elements in relative movement to index them in various positions and immobilize them relatively in these positions. Finally, only part of the railing, or a second railing, doubling the first permanently fixed to the wall 11, can be mobile.

In this figure 2, there is also the latch 25 associated with the trigger 27 located on the rail and with a trigger 29 adapted to be operated by a stop 29 a of the railing brought into the high position.

Figures 3 and 4 illustrate means for operating the panel 2 which include a pedal for unlocking and actuating it from the upper face and a handle for actuating it from its lower face. They also include optional locking means condemning the possibility of operation from the upper face of the panel.

Thus, the panel 30 has a recess 38 in which is housed a pedal 39. This pedal is rotatably mounted on a rod 40 by means of a stop ball 41. The rod 40 passes through the panel 30 and comprises a lug 42 radial cooperating with an oblique slot 43 formed in a bolt 44 which can be received by a keeper 45 of the sliding frame when the panel 30 is in the closed position of the opening. A spring 46 tends to constantly push the bolt 44 into the keeper. It is understood that a vertical movement of the rod 40 downwards acts on the bolt which returns to its housing in the panel 30 against the force of the spring 46. The slope of the inclined slot and the force of the spring 46 are chosen so that the movement is reversible and that in the absence of any external force the lug 42 is in its position in FIG. 4.

Under the bottom wall of the housing 38, the pedal 39 has a flange 47, comprising a V-shaped notch 48. The panel 30 comprises, in the space which accommodates the flange 47, a projecting element 49 which interferes with this flange for prevent it from descending unless the notch 48 is vertically in line with this projection 49. A spring 50, harnessed between the bottom of the housing and the pedal tends to place the latter in an angular position (for example in abutment on a fixed element not shown) in which the notch 48 is offset relative to the projection 49.

The rod 40 is provided at its other end (projecting under the panel 30) with an operating handle 51 making it possible to pull it down and to move the panel 30.

This embodiment is suitable for a specific type of access condemnation by means of a lock or a similar blocking device. Thus, in Figure 3, there is shown a lock 56 whose bolt 57 can be moved between an active position in which it is present under the pedal 39 and an unlocking position in which it is outside of this pedal. This lock 56 is accessible from the upper face of the panel 30.

The user wishing to reach the ladder from the upper level, after actuating the lock 56, places his foot on the pedal 39 to rotate it in the direction of the arrow A. The rotation, of the order of 30 to 60 °, will be limited by a stop not shown, which stops the pedal in its angular position where the notch 48 is directly above the projection 49. Depression of the pedal is possible, which causes the withdrawal of the bolt 44 out of the keeper 45, by the downward movement of the rod 40 in the bolt 44. The user can still push the panel with the foot to clear access to the ladder or to the lower section of the latter. The need to rotate the pedal to depress it eliminates any risk of inadvertent depressing of the latter at the simple passage of a person.

If the user is under the panel, going up the ladder, he just has to pull on the handle 51 to unlock the panel 30. It is noted that this maneuver does not cause movement of the pedal which is not axially linked to the rod 40. The movement of the panel can therefore be made even if access from above is blocked by the lock 56.

This provision constitutes, in addition to the "security airlock" that the invention creates at the top of a ladder, a means of selective condemnation of access to the ladder preserving the free crossing of this access for any person escaping from the restricted area.

Claims (11)

1. Device for protecting access to a ladder (3) from an upper floor (1) characterized in that it comprises a platform (5) movable between a first position close to the ladder ( 3) and a second position remote therefrom, and a railing (8) extending above the level of the platform (5). 2. Device according to claim 1, characterized in that the platform (5) comprises maneuvering means (9 a , 9 b ) to move it from the first to the second position, arranged on each of its lower faces and higher, and an automatic return member (7) from its second to its first position. 3. Device according to claim 2, characterized in that the platform (5) is located under the floor (1) and that the railing (8) extends between the floor (1) and the platform (5). 4. Device according to claim 3, characterized in that the platform (5) has means (25) for locking it in its first position. 5. Device according to claim 4 applied to crinoline ladders, characterized in that it comprises, at the upper floor (1) a hatch (2) for access to the ladder (3) and means (24) for unlocking the platform (5) cooperating with the hatch when the latter is in its closed position for access to the ladder. 6. Device according to claim 4 applied to ladders provided with a rail or a slide (4) anti-fall to receive a slide connected to a harness coated by the user, characterized in that it comprises, at the level from the upper floor (1) a hatch (2) for discovering and closing the access opening to the ladder (3) of the means (24, 27) for unlocking the platform (5) cooperating with the hatch ( 2) when the latter is in its closed position for access to the ladder and with the slide during its introduction into the anti-fall rail (4). 7. Device according to claim 3, applied to ladders provided with a rail or an anti-fall slide intended to receive a slide connected to a harness coated by the user, characterized in that at least part of the guard -body (8) is movable from a first position located above the platform (5) and below the level (N) of the floor (1) to a second position where it is located at least partially, at - above the floor (1). 8. Device according to claims 4 and 7, characterized in that it comprises unlocking means (27, 29) of the platform (5) cooperating with the railing (8) when the latter is in its second position and with the slide during its introduction into the anti-fall rail (4). 9. Device according to claim 5 or claim 6, characterized in that the hatch is a panel (2) sliding in a structure of the floor (1) which comprises operating means (39, 51) on each of its faces, automatic return means in its closed position and locking means comprising a bolt (44) carried by the panel (30) with horizontal sliding associated with a vertical control rod (40) terminated in the lower part by a handle ( 51) to pull it down, which constitutes one of the means for operating the panel, and cooperating in the upper part with a pedal (23, 39) for driving the rod which constitutes the other means for operating the panel . 10. Device according to claim 9, characterized in that the pedal (39) is mounted to slide vertically in the panel (30) and to rotate relative to this panel, means (48, 49) for angular indexing being provided. between the pedal and the panel to allow the pedal to be depressed only in a determined angular position of the latter relative to the panel, an elastic return member (50) being coupled between the pedal and the panel to move the pedal away from this position. 11. Device according to claim 10, characterized in that it comprises locking means (57) of the pedal in the high position, associated with a lock (56) accessible by the upper face of the panel (30).

Images