DEVICE FOR MANAGING ACCESS TO AND THE USE OF A LADDER

Description

[0001] The present invention relates to the management of access to and use of a ladder, inclined or not, to prevent access to any unauthorized person and to allow safe use of this ladder for the authorized user. Technological background

[0002] It is known to block access to a ladder, particularly a caged ladder, by folding a panel down over its lower rungs. This panel is usually fitted with a top cover designed to seal the entrance to the cage, thus further restricting access.

[0003] It is also known to restrict access to a ladder, particularly an inclined one, by means of a panel attached to the back of the ladder (DE202011102506U1). It should be noted that this restriction is quite rudimentary and does not meet the requirements for ladder use as prescribed by several standards and regulations concerning labor law, user safety and protection, and employer liability.

[0004] Document US-2006 / 076188-A1 describes a complex articulation device for such a panel on a ladder. Object of the invention

[0005] The present invention aims to provide a device for locking access to a ladder which can not only effectively prevent access to any unauthorized person but also ensure that the authorized user can use the ladder safely and with the greatest possible comfort. Brief description of the invention

[0006] For this purpose, the invention relates to a device for managing access to and use of a ladder according to claim 1.

[0007] This distance allows the panel to be positioned so that the user can place their foot correctly, safely and comfortably on the first rung, once the lock has been removed.

[0008] The panel can take various forms. The simplest is a sheet of metal mounted on a frame or box to give it sufficient rigidity. It can take a more complex form, notably to provide at least a partial closure of the space between the bars, either by stamping, or by cutting a panel into a box shape or by bending (folding) it lengthwise to allow the passage of the bars, etc.

[0009] In a preferred embodiment, the hinge axis of the panel to the ladder is located below the lower transverse edge of the panel. Tests have shown that this position is the most convenient for the user, both for locking and unlocking access to the ladder and for allowing them to comfortably place their foot on the first rungs.

[0010] Advantageously, when the ladder is equipped with a crinoline, the panel is provided in the upper part with a cover, of a width less than the spacing of the ladder uprights, capable of at least partially closing the internal passage of the crinoline.

[0011] It has been observed that, surprisingly, it is more comfortable for the user resting on the platform, for example during descent or when using it as a resting platform, if the platform, when engaged in the safety cage, is roughly parallel to the ground, thus providing the user with the same sensation as when standing at the foot of the ladder. This can be achieved either by a flat platform mounted at the top of the panel at an angle slightly less than 90 degrees, depending, of course, on the angle of inclination of the ladder, or by a "cylindrical" platform whose upper surface is centered roughly on the hinge axis.

[0012] In certain embodiments, the lock can be held in the open position, the device, in which the panel is hinged to the ladder at the bottom, is equipped for this purpose with a return mechanism for said panel against the rear face of the ladder and a mechanism for retaining the panel in its state away from the ladder, carried by the end of the cover away from the panel to cooperate with an element of the ladder, preferably a rung, under which the cover passes through the plane of the ladder.

[0013] In this embodiment, the envisaged retention mechanism consists of a retractable stop normally projecting above the free end of the panel, which can be erased either by a rung of the ladder when passing under this end, under the latter, when the locking mechanism is opened, against the effect of a return device, or by an operating linkage comprising, at the level of the foot of the ladder, a manual actuation device for erasing this stop to allow the panel to be lowered under the effect of its return device.

[0014] It is also advantageous for the panel to be locked in its locked position, that is, when it is folded down against the ladder. To this end, the invention proposes equipping the panel with a quarter-turn bolt which is normally engaged in a strike plate mounted on the ladder. To release the bolt, a bolt operating key is provided, acting either directly on the bolt or via a transmission, if the strike plate (and any locking mechanism) is located on the ladder at a level inaccessible to the user at the foot of the ladder, and a pedal, located on the cover, connected to the bolt by a linkage.

[0015] Thus, the user at the foot of the ladder, authorized to climb it, can release the bolt from its strike plate using a personal key, possession of which signifies their authorization. They then push the panel to pivot it around its lower hinge until the retaining stop engages. After climbing the lower rungs of the ladder, they use their foot to release the stop. The panel is then automatically returned to the ladder, and the bolt is re-engaged in the strike plate.

[0016] During descent, the user uses their foot to activate the pedal to release the bolt from its strike plate and simultaneously pushes the latch back along the ladder until the retaining stop engages, allowing them to continue descending to the ground. Finally, they operate the stop's operating mechanism to disengage it, enabling the ladder to pass under the rung and fold down against the rear face of the ladder.

[0017] The invention will be better understood with the aid of the following description of an embodiment and certain variants thereof. Brief description of the drawings

[0018] Reference will be made to the attached drawings in which: there figure 1 is a partial perspective view of a ladder equipped with the device, showing more particularly a lower part of the locking panel according to a first embodiment, the figure 2 is a partial perspective view of a ladder equipped with the device, showing more particularly an upper part of the locking panel according to a second embodiment, the figure 3 is a perspective view of a condemnation panel fitted with a top cover, the figure 4 is a side view that illustrates an advantageous arrangement of the device according to the invention, the figure 5 is a perspective view illustrating the means of controlling the device of the invention for an authorized user, the figure 5a is a partial detail view extracted from the figure 5 , there figure 5b is another partial detail view extracted from the figure 5 , there figure 6 is a perspective view of a ladder equipped with a device according to a third embodiment, the figure 7 is a perspective view of a ladder equipped with a device according to a fourth embodiment, the figure 8 is a perspective view of a ladder equipped with a device according to a fifth embodiment. Detailed description of the invention

[0019] The inclined ladder 1 shown in figures 1 et 2 The ladder to which the device of the invention applies comprises horizontal rungs 2 between two lateral uprights 3 and 4. The device of the invention includes a panel 5 whose length is sufficient to cover several rungs 2 of the ladder 1 and whose width is at least substantially that of the ladder between the uprights 3 and 4. This panel is shaped so that its common cross-section has a central portion which, in the case of these figures, crosses the mean plane of the ladder 1 (the mean plane is the plane parallel to the rungs 2 and the uprights 3, 4 and which passes through the middle of the rungs and uprights), in other words, said central portion of the panel 5 passes between the rungs 2 until it extends beyond the mean plane of the ladder 1. The function of this configuration is to make the rungs 2 of the ladder 1 inaccessible by making it impossible to place a foot on them or to grasp them with a hand.Indeed, the central part of the panel 5 then sufficiently occupies the space between the rungs 2 to prevent the user's foot or hand from penetrating this space to properly support or grip the lower rung. The rungs 2 are then housed in cutouts 6 made in this central part when the panel 5 is folded down onto the ladder, which allows the central part to partially occupy the space between the rungs.

[0020] To the figure 1 The panel 5 is hinged to the ladder around an axis 7 parallel to the rungs 2, at its lower end, specifically by means of arms 8 and 9 extending the panel 5 downwards beyond its lower edge 5a. It is understood that the arms 8 and 9 allow for a panel in which the axis 7 is positioned away from the lower edge 5a along the longitudinal direction of the panel 5 (and of the ladder 1 when the panel 5 is folded against the ladder 1). Thus, when the panel is pulled away from the ladder, as shown, the lower part of the panel 5 is sufficiently far from the ladder for the user's foot to find proper support on the first exposed rung.

[0021] To the figure 2 The panel 5 is hinged to the ladder 1, which has a safety cage 1a, also around a transverse axis 10 by the two arms 11 and 12 that extend its upper part beyond its upper edge 5b. It is understood that the arms 11 and 12 allow for a panel in which the axis 10 is positioned away from the upper edge 5b along a longitudinal direction of the panel 5 (and of the ladder 1 when the panel 5 is folded against the ladder 1). Thus, as before, this allows the user's foot to rest properly on the last rung exposed by the panel when it is pulled away from the ladder.

[0022] Note that panel 5 is located at the rear of ladder 1 so that the effect of gravity tends to move it away from it.

[0023] There figure 3 This represents a variant embodiment of panel 5 in which it is formed of a box whose front face 13 has cutouts 6. This box defines an interior space between this cut-out front face 13 and a solid rear face which allows for the housing of control mechanisms as illustrated below. The panel has an upper opening 14, substantially perpendicular to face 13, and whose width is less than the spacing of the ladder's uprights. This opening is designed to pass between two rungs 2 to form an obstacle to accessing the ladder, particularly if it is a caged ladder, and to provide a resting platform for a ladder user located above the panel. It should be noted that this opening has, at its free end, a pedal 15 and a retractable stop 16, which will be described in more detail below.

[0024] To the figure 4 , we see a sign similar to the one in the figure 3 , associated with a ladder 1 equipped with a safety cage 1a. The panel 5, in addition to the hinge 7, is pulled back against the ladder by a return mechanism 17, here a pair of gas springs, against the effect of gravity. The return force will be adjusted so that the user exerts only minimal effort to manually detach the panel 5 from the ladder 1, aided by the effect of gravity.

[0025] It should be noted, on this figure 4 The upper surface of the cover 14 is not strictly perpendicular to the panel 5. It has an angle A relative to this panel that depends on the angle of inclination B of the ladder 1 relative to the horizontal (the ground), so that when the panel 5 is folded down against the ladder 1, the user resting on the cover 14 has a sensation similar to that experienced when at the foot of the ladder 1 at the end of the descent or the beginning of the ascent. Thus, for example, when the inclination B of the ladder 1 is 80 degrees, the angle between the panel and the upper surface of the cover is 84 degrees, give or take a few degrees, in particular to take into account the proximity that the end of the cover must maintain with the rung 2 of the ladder 1 under which it passes, in order to implement a stop to maintain the panel 5 in the open position as described below.

[0026] To figures 3 et 4 We have also represented, on the one hand, a push button 18 and on the other hand, a cylinder 19, for example that of a key lock.

[0027] These two elements can be found on the figures 5 , 5a et 5b .

[0028] There figure 5 This diagram therefore shows the various mechanisms allowing the user to operate the device of the invention in order to meet the latest regulatory requirements for safety and ergonomics. More specifically, the mechanisms shown are transmission elements, connecting on the one hand a locking bolt P to the lower cylinder 19 and to the upper pedal 15 for operating this bolt P, and on the other hand connecting the retractable stop 16 to the push button 18. These mechanisms are housed in a box-shaped panel such as the one referenced 5 on the figure 3 , whose face 13 is turned towards the ladder (of which only one rung 2 is shown in the figure 5b ) and in the operculum 14 also made in the form of a box.

[0029] On a common support 21 housed in the cover 14, the pedal 15 and the stop 16 are pivotally mounted, the former so that it can be pressed against a return mechanism and the latter so that it is held in protrusion above the end of the cover by its own return mechanism. The return mechanism of the pedal 15 is, for example, dimensioned so that the pedal 15 can only be pressed by the application of a relatively significant force (for example, about twenty daN) in order in particular to prevent accidental depressment of the pedal 15 (and therefore unintentional opening of the cover 14) by the user when descending the ladder or to prevent any attempt to open it manually from the bottom of the ladder.

[0030] To figures 5 And 5aThis mechanism isolates the locking mechanism from the deadbolt. When depressed, the pedal 15 pivots upwards around a fixed axis 22, pivoting a lever 23 which acts on the end of a pivoting lever 24. The other end of this lever pushes down a rod 25, which in turn acts on another lever 26. This lever is coupled in a lock 27 to the bolt P, which it raises to disengage it from a strike plate (not shown) carried by a rung 2 of the ladder. Upon releasing the lever, internal return mechanisms bring the mechanism back to its locked state.

[0031] The quarter-turn bolt P, which normally protrudes from the lock, can be retracted by operating the cylinder using a key specific to the authorized user. This operation of the bolt via the cylinder is achieved by a linkage 28 and is independent of the operation of the bolt P by the pedal 15.

[0032] With reference to figures 5 And5b , which isolates the locking panel 5 retaining mechanism, the pusher 18 is mounted pivoting around the fixed axis 20 and acts on the rod 29, which rotates the pusher 30 around a fixed axis 31. The pusher 30 slides a rod 32 which rotates the stop 16 around an axis 33. Internal return elements in this transmission place the stop 16 in projection relative to the cover 14.

[0033] The authorized user, in front of the locked gate, operates the cylinder 19 with their key or any other operating device. The rod 28 associated with it retracts the bolt P into the lock 27. The panel 5 can then be manually moved away from the ladder until the stop 16, sliding and retracting under a rung 2 of the ladder (this rung is hereafter called the stop rung to distinguish it from the others) thanks to the slope it presents at its upper part, comes back out behind this rung and holds the moved panel against its return device 17. The user comfortably crosses the rungs thus exposed until reaching a rung 2 above the stop rung which cooperates with the stop. He can then easily press (directly or via an intermediary mechanism) with his foot on the stop 16 which can then pass back under the stop bar and allow the panel to be folded down by the return mechanism 17.The lock is then re-engaged, prohibiting access to anyone not possessing the appropriate means of operating the cylinder 19.

[0034] Upon descending, the user finds the locking mechanism engaged and the catch 14 locked between the bars 2. By pressing the pedal 15, which pivots around a fixed axis of the support 21 located at its outermost end relative to the catch 14, the user releases the bolt P from its strike plate as described above, thus unlocking the panel 5. The user can then move the panel aside with their foot by pushing the catch 14 through the ladder 1 until the stop 16 engages behind the locking bar. The user can then continue descending to the ground. At this moment, by acting on the push button 18, it activates the transmission described above in the direction of an erasure of the stop 16 inside the operculum 14. The panel 5, thus freed from its restraint, recalled by the return member 17, returns to press itself against the ladder and the bolt P engages in its strike plate behind a bar 2.

[0035] On the figures 6 à 8 , we find a 1:1 scale, without a crinoline, equipped with a panel 5 formed of a box and articulated to the 1:1 scale via arms 8, 9 as in the figures 3 et 4 .

[0036] In these embodiments, the panel 5 has an upper part connected to each of the uprights 8, 9 by a compass 40 comprising a first connecting rod 40.1 having one end articulated to the upright 8, 9 and an opposite end articulated to one end of a second connecting rod 40.2 having an opposite end articulated to one side of the upper part of the panel 5.

[0037] The first connecting rod 40.1 is extended beyond its articulation to the second connecting rod 40.2 by a lever to the free end of which is attached one end of a return member 41 having an opposite end attached to a lug integral with the end of the second connecting rod articulated to the panel 5. The return member 41 tends to fold the panel 5 against the ladder 1.

[0038] With reference to the figure 6 , and according to the third embodiment, the upper end of panel 5 is provided with a lid 14 as on the figure 3 However, the ladder is vertical and no longer inclined.

[0039] In the modes of embodiment of figures 7 And 8 , panels 5 do not have a lid 14 and implement a slightly different mechanism for manipulating panel 5 when the user is on ladder 1 above panel 5.

[0040] This mechanism includes a rod 42 mounted to slide along the upright 8 of the ladder 1 parallel to said upright. The rod 42 includes a first end 42.1 articulated to a first end of a third connecting rod 43 having a second end articulated at a midpoint of the first connecting rod 40.1. The rod 42 includes a second end 42.2 associated with an operating member.

[0041] In the implementation of the figure 7 , the operating mechanism is a pedal 44 which can be operated by the user's foot when his feet are on a bar 2 located above the upper edge 5b of the panel 5.

[0042] In the implementation of the figure 8 , the operating mechanism is a handle 45 operable by the user's hand when his feet are on a bar 2 located above the upper edge 5b of the panel 5.

[0043] In the modes of embodiment of figures 7 And 8 The stop preventing panel 5 from folding down against ladder 1, against the force of the return mechanism 41, is not shown. This stop could, for example, be a lock, a rotational indexing of the handle or pedal...

[0044] Of course, the invention is not limited to the embodiments described but encompasses any variant falling within the scope of the invention as defined by the claims. In particular, it is possible to have a panel of the type of that of the figures 1 et 2 with a lid like that of the figure 3 and, possibly, with a locking mechanism like that of the figures 5 , 5a, 5bRegardless of the embodiment, the ladder may be inclined or vertical, with or without a crinoline. In the case of a vertical ladder, a substantially horizontal latch is preferably used. The bolt may be connected to a locking catch, a lock, or any other locking mechanism. The return mechanism may be arranged to hold panel 5 in the open position, particularly when the hinge axis is above panel 5. The latch may occupy all or part of the cross-section of the crinoline. The latch may be arranged to extend to the lower end of the crinoline or within it.In certain embodiments designed to meet regulatory or normative safety requirements, such as those requiring the locking mechanism to remain in the open position, the device, in which the panel is hinged to the ladder at its lower end, is equipped with a mechanism to return the panel to a position away from the rear face of the ladder. A means of locking the panel in the open position can be provided, for example, a padlock that can be engaged in the hinged stay, which is attached to the ladder on one side and to the panel on the other, to hold the stay in its extended state. The stop can be designed to retract into a recess in the cover to prevent injury to an operator who might fall onto the cover.

Claims

1. Device for managing access to and use of a ladder (1) extending between a lower level and a protected upper level, lower access to said ladder being restricted, said device comprising a means for prohibiting or preventing the use of at least some of the rungs of said ladder that is formed of a panel (5) and means for connecting said panel to the ladder, which means hold the panel, in a first state, applied against a face of the ladder that is opposite the access face thereof and, in a second state, at a distance from said face of the ladder, characterised in that the means for connecting the panel to the ladder comprise a hinge (7, 10) which has an axis parallel to the rungs (2) of the ladder (1) and stationary with respect to the ladder and which hinges the panel to the ladder about said axis and which is at a distance, in a longitudinal direction of the panel outwards from the panel, from the transverse edge (5a, 5b) of the panel (5) closest to said hinge.

2. Device according to claim 1, characterised in that the panel (5) is of such a shape that it, in particular, at least partially blocks the inter-rung space.

3. Device according to claim 1 or claim 2, characterised in that the axis of the hinge (10) of the panel (5) to the ladder (1) is located above the upper transverse edge (5b) of the panel (5).

4. Device according to claim 1 or claim 2, characterised in that the axis of the hinge (7) of the panel (5) to the ladder (1) is located below the lower transverse edge (5a) of the panel (5).

5. Device according to claim 4, characterised in that the panel (5) is provided in the upper part with an operculum (14), of a width that is less than the spacing of the side rails (3, 4) of the ladder (1).

6. Device according to claim 5, characterised in that the upper surface of the operculum (14), when same is engaged in the ladder (1), is substantially parallel to the ground so as to provide the user with the same feeling as when they are at the bottom of the ladder (1).

7. Device according to claim 5 or claim 6, characterised in that the panel (5) is equipped with a member (17) for returning the panel against the rear face of the ladder (1) and with a mechanism (16) for holding the panel (5) in the state thereof at a distance from the ladder, which mechanism is supported by the end of the operculum (14) that is remote from the panel (5) in order to cooperate with an element (2) of the ladder in the vicinity of which the operculum crosses the plane of the ladder (1).

8. Device according to claim 7, characterised in that the above-mentioned element is a rung (2) under which the operculum (14) passes.

9. Device according to any of claims 5 to 8, characterised in that the panel (5) is equipped with a quarter-turn bolt (P) that is normally engaged in a strike plate supported by the ladder (1), with a key for manoeuvring the bolt that acts thereon via a transmission (19, 28) if the strike plate is located on the ladder at a level that is inaccessible to the user at the bottom of the ladder and with a pedal (15) that is supported by the operculum (14) and is connected to the bolt via a transmission linkage (23, 24, 25, 26).