FR2717221A1 - Safety device for lifting ladder. - Google Patents

Abstract

Safety device for a lifting ladder (1) adjustable in height provided with a handrail (3) over at least part of its length and supporting at its free end a working basket (2) adjustable in inclination with respect to the ladder (1) so that its floor (9) is kept horizontal in all working positions of the ladder (1), characterized in that it comprises a gripping element (4) articulated on the basket (2) and on the scale (1) so as to constantly adapt to the relative inclination of the basket and the scale.

Description

- I -

  SECURITY DEVICE FOR A LIFT LADDER

  The present invention relates to a work or rescue basket, intended to be mounted at the end of an orientable and telescopic machine, such as a fire-fighting ladder or a

lifting arm.

  Ladders or lifting arms used to fight fires are generally equipped at their upper end with a work or rescue basket, which makes it possible to transport personnel to the desired altitude and, optionally, to keep them there during the execution of its task. These baskets, such as that described in the publication EP O 465 985 are most often associated with control means which maintain their floor

  horizontal during the operation of the ladder or the lifting arm.

  In the absence of any particular provision, the user must let go of the handrail of the ladder at its upper end, before being able to grip the basket. Passing the ladder through the basket or from the basket over the ladder is therefore a dangerous operation. The present invention aims to ensure the safety of people during their passage in both directions between a lifting ladder,

  and a work or rescue basket.

  To this end, it offers a safety device for a height-adjustable lifting ladder provided with a handrail over at least part of its length and supporting at its free end a work basket adjustable in inclination relative to the scale so that its floor is kept horizontal in all the working positions of the ladder. This device is characterized in that it comprises a gripping element connected to the basket and to the scale, so as to constantly adapt to the relative inclination

of these.

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  2 - According to one embodiment of the invention, the gripping element is articulated on an element of the basket and on a slide sliding freely along the handrail. According to one embodiment of the invention, the gripping element comprises at least two bars hinged together, connected

  respectively to an element of the basket and to a fixed point on the scale.

  According to one embodiment of the invention, the basket element is

an upper arm of it.

  According to one embodiment of the invention, the arm can pivot on an upright of the basket by its end opposite to the gripping element, so as to allow the alignment of said arm, and of the gripping element along the handrail, when the

  basket is tilted under the ladder to the transport position.

  According to one embodiment of the invention, the slide joins the free end of the handrail, when the ladder reaches its

highest position.

  According to one embodiment of the invention, the bar of the gripping element articulated on the slide is parallel to the handrail

  in the highest position of the ladder.

  According to one embodiment of the invention, the gripping element slides freely inside a sheath, articulated by its

  opposite end to the basket on a fixed point of the handrail.

  According to one embodiment of the invention, in the highest position of the ladder, the sheath is applied against the handrail,

  and aligned with the grip.

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  -3- According to one embodiment of the invention, the gripping element

is rigid.

  The invention will be better understood on reading the description

  following of a particular embodiment thereof, in conjunction with the accompanying drawings, in which: - Figure 1 shows the end of a lifting ladder and its working basket in the absence of a safety device, - Figure 2 shows the same scale and the same basket, fitted with the safety device of the invention, - Figure 3 is a view of the same lifting ladder in a horizontal position, - Figure 4 corresponds to Figure 3 after folding of the basket in the transport position, - Figure 5 is a view of the same scale in the lower position, - Figures 6, 7 and 8 illustrate a first variant of the invention, and - Figures 9, 10 and 11 illustrate a second variant of the invention. The free end of the rescue ladder 1 shown in FIG. 1 supports a work or rescue basket 2 by means of an articulated strut 10. Conventionally, control means not shown, keep the floor 9 of the basket 2 horizontal, regardless of the inclination of the ladder 1 (75 in the example shown). This figure highlights the existence of a discontinuity between the upper end of the handrail 3

  provided on ladder 1 to facilitate its ascent, and basket 2.

  As indicated above in the absence of any specific provision 49391 16l -4, the passage from scale 1 to basket 2 or vice versa, from basket 2 to scale 1 presents a certain danger, mainly due to the need to let go of the handrail 3 before gripping the basket 2, or vice versa letting the basket 2 before gripping the handrail 3. According to the invention, it is proposed to connect these two ends by means of a safety device. This device comprises a gripping element 4, preferably rigid, articulated on the one hand at a point 5 of the basket 2, such as the connection point of an upright 7 of the basket 2 and of an upper arm 8 thereof. ci, and on the other hand on an element belonging to the scale or attached to it, for example a slide 6

  sliding freely along the handrail 3.

  The displacement of the slide 6 on the handrail 3, as well as the respective articulations of the gripping element 4 on point 5 of the basket 2 and on the slide 6, allow the gripping element 4 to move with the basket 2 with respect to the scale 1, as a function of the relative inclination of the basket 2 with respect to the latter, this relative inclination varying, as indicated above, as a function of the absolute inclination of the scale, so as to maintain in all circumstances the floor 9 of basket 2, horizontal. The user thus has a continuous gripping means between the basket 2 and

scale 1.

  As shown in Figure 2, it is also very advantageous to give the gripping element 4 a length such that the slide 6 reaches the upper end of the handrail 3 when the ladder 1 reaches its highest position , so as to place in this situation the gripping element 4 substantially in the

extension of the handrail 3.

  Figure 3 shows the relative position of the basket 2 and the gripping element 4, when the ladder is in a working position

horizontal.

  -5- In Figure 4, the basket 2 has abandoned its horizontal working position to reach, by tilting conventionally around

  the strut 10, its transport position, covering the ladder 1.

  It will also be noted that the arm 8 on which the end of the element 4 is fixed has left the end 5 of the upright 7 by pivoting around the opposite upright 14 to be stored along the handrail 3,

  in the extension of the gripping element 4.

  This arrangement makes it possible in particular to facilitate the tilting of the basket 2 around the strut 10, and to reduce

  the size of the device in the transport position.

  FIG. 5 shows that the device proposed by the invention also adapts to the passage of the scale 1 below the horizontal to the extent, of course, where such an inclination is authorized by

  all of the tilting means.

  Figures 6 to 9 illustrate a first variant of the invention, according to which the gripping element 4 comprises at least two articulated bars 11, 11 '. The two bars 11, 11 'appearing in these figures have a common point of articulation 12 and are connected respectively to the fixed point 5 of the basket 2 mentioned above, and to a fixed point 13 of the handrail 3. As shown in the figure 7, the angle a of the two bars 11, 11 ′ is open when the ladder is in the high position while it closes when the ladder descends towards the horizontal (FIG. 6), and crosses the horizontal position (FIG. 8). Finally, it can advantageously be provided that the bar 11 ′ articulated on the handrail 3 is parallel to the latter, when the scale 1 reaches its lowest position, as can be illustrated by way of example by the Figure 8. As we will have noticed, this variant allows, in a simple way, to give up the use of a sliding member along the handrail. Furthermore, it should be noted that FIGS. 6 to 9 relate to a particular embodiment of the gripping element 4, this one

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  -6- which can just as easily have a number of articulated bars

  greater than two, without departing from the scope of the present invention.

  Finally, FIGS. 9, 10 and 11 propose a second variant of the invention, according to which, the gripping element 4 slides freely inside a sheath 14, articulated by its end

  opposite to the basket 2, on a fixed point 15 of the handrail 3.

  As shown in Figure 9, this arrangement leaves the possibility of debating horizontally. Like the main embodiment of the invention and its first variant, it can advantageously be provided that in the highest position of the ladder (see FIG. 10), the sheath is applied against the hand

  current, and aligned with the grip.

  In conclusion, the invention provides, in its main embodiment and in its two variants, a safety device comprising a continuous gripping element easily gripped by the user, when passing from the ladder to the basket or from the basket toward the ladder. This device is permanently adapted to the relative position of the ladder and the basket. Furthermore, it has a reduced bulk when the basket is tilted in the transport position.

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Claims (1)

REVENI) ICATIONS [1] Safety device for lifting ladder (1) adjustable in height provided with a handrail (3) over at least part of its length and supporting at its free end a work basket (2) adjustable in inclination relative to the ladder (1) so that its floor (9) is kept horizontal in all the working positions of the ladder (1), characterized in that it comprises a gripping element (4) connected to the basket (2) and scale (1) so as to constantly adapt to the relative inclination of the latter. [2] Safety device according to claim 1, characterized in that the gripping element (4) is articulated on an element (8) of the basket (2) and on a slide (6) sliding freely along the hand current (3). [3] Safety device according to claim 1, characterized in that the gripping element (4) comprises at least two bars (11, 11 ') hinged together, connected respectively to an element (8) of the basket (2 ) and at a fixed point (13) of the scale (1). [4] Safety device according to claims 1, 2 or 3, characterized in that the element (8) of the basket (1) is an upper arm thereof. [5] Safety device according to claim 4, characterized in that the arm (8) can pivot on an upright (7) of the basket (2) by its end opposite to the gripping element (4), so as to authorize the alignment of said arm (8), and of the gripping element (4) along the handrail (3), when the basket (2) is tilted under the ladder (1) in the transport position. [6] Safety device according to claims 1, 2, 4 or 5, characterized in that the slide (6) joins the free end of 4939 1 67E   -8- the handrail (3) when the ladder (1) reaches its position the higher.   [7] Safety device according to claims 1, 3, 4 or 5,   characterized in that the bar (11 ') of the gripping element (4) articulated on the handrail (3) is parallel to the latter   in the highest position of the ladder (1).   [8] Safety device according to one of claims 1, 4 or 5,   characterized in that the gripping element (4) slides freely inside a sleeve (14), articulated by its end opposite to the basket on a fixed point (15) of the hand current (3).   [9] Safety device according to claim 8, characterized in that in the highest position of the ladder, the sheath is applied against the handrail, and aligned with the element of grip (4).   [10] Safety device according to one of claims   previous, characterized in that the gripping element (4) is rigid.