WO2003042484A1

WO2003042484A1 - Collapsible ladder

Info

Publication number: WO2003042484A1
Application number: PCT/SE2002/001812
Authority: WO
Inventors: Kenneth Söder
Original assignee: Scania Cv Ab (Publ)
Priority date: 2001-11-14
Filing date: 2002-10-04
Publication date: 2003-05-22
Also published as: JP2005509768A; SE522451C2; EP1451434A1; SE0103786L; SE0103786D0

Abstract

The invention relates to a collapsible ladder (2) comprising a first stile (4), a second stile arranged substantially parallel with the first stile (4), and at least one rung (8, 10, 12) attached hingingly (at 9, 11) to each of the stiles (4, 6). The two stiles (4, 6) are attached hingingly (at 18, 20) to a sliderail (16) on which the fastening points (18, 20) for the stiles (4, 6) are movable steplessly. One end (36) of a control rod (34) is arranged hingingly but not movably on the first stile (4) and its other end (38) is arranged hingingly but not movably on the sliderail (16).

Description

COLLAPSIBLE LADDER

Technical field

The present invention relates to a collapsible ladder adapted to be attached to an external structure.

Background

Collapsible ladders are appropriate in applications where it is desired to store a ladder in such a way that it occupies the least possible amount of space when not in use.

An example of a collapsible ladder is referred to in CH A5 652797 which refers to a collapsible ladder intended to be fastened to a building or scaffolding. That ladder comprises a first stile intended to be attached firmly to the building or scaffolding by means of brackets, a second stile arranged for movement with respect to said first stile, and a number of rungs each fastened hingingly to both stiles. When the ladder is in its retracted position, the stiles fit into one another with their U-shaped cross-sections placed against one another so that the flanges of the U-sections extend across one another. A locking arrangement is provided to hold the ladder in its retracted position in order to prevent unauthorised used of the ladder. When the locking arrangement is released, the force of gravity makes the movable stile drop always to a vertical position and each rung change from the original nearly vertical to a final horizontal position of use.

One problem with ladders of this kind is that they can only be stored in a vertical position. Another problem with ladders of this kind is that they can only be stored where they are used, since one of the stiles cannot be moved.

Brief description of the invention The problem of the ladder only being storable in a vertical position and the problem of one of the stiles not being movable are solved according to the invention by arranging a collapsible ladder which comprises a first stile attached hingingly to an external structure, a second stile arranged substantially parallel to the first stile and likewise attached hingingly to an external structure, and at least one rung attached hingingly to each of the stiles. The collapsible ladder according to claim 1 affords the advantage that the collapsible ladder can be stored in a non- vertical position and the advantage that both stiles are movable. It also solves the problem of achieving a more spatially controlled extension and retraction of a ladder which has both stiles hinged, making it easier, for example, to optimise the surroundings of the ladder without risk of the ladder striking anything in its surroundings.

The characteristics stated in the dependent claims result in the following further advantages: the ladder will be very robust in the extended state because of its torsional rigidity due to the rounded cross-section of the parts of the ladder, and it can therefore be made of parts of smaller dimensions than previously used, the ladder is inexpensive to make, since it is made of extruded aluminium without welds or other joints, the ladder is comfortable to climb in the extended state without shoes on the feet, because of its rounded rungs, space is also saved in the ladder's extended position because, for example, space is gained for a refrigerator below the shorter stile, the ladder is very compact in the retracted state, and the ladder can be integrated in a truck bunk and thus be completely out of the way when not in use.

Brief description of the drawings

The invention will now be explained in more detail below with reference to the attached drawings, in which: Figure 1 depicts schematically a collapsible ladder according to first embodiment of the invention in the fully extended position of use, as seen from in front,

Figure 2 depicts schematically a collapsible ladder according to Figure 1 in a partly extended position, as seen from in front,

Figure 3 depicts schematically a collapsible ladder according to Figure 1 in the fully retracted storage position, as seen from above,

Figure 4 depicts schematically a cross-section JN-IN from Fig. 3 of a collapsible ladder in the fully retracted storage position,

Figure 5 depicts schematically in perspective view a retraction mechanism of a collapsible ladder according to a preferred first embodiment of the invention, and

Figure 6 depicts schematically a collapsible ladder according to a second embodiment of the invention in the fully extended position of use, as seen from in front.

Description of preferred embodiments

The invention will be described below as arranged inside a truck cab. This should only be regarded as an example of a preferred application of the invention among several possible conceivable applications of the invention, a number of which will be mentioned later.

Figure 1 depicts a collapsible ladder 2 according to a first embodiment of the invention in the fully extended position of use, as seen from in front. The collapsible ladder 2 comprises a first stile 4 (shown in the diagram as the left stile), a second stile 6 (shown in the diagram as the right stile) arranged substantially parallel to the first stile, and three rungs 8,10,12 hingingly connected at 9,11 to each of the stiles 4,6. It is also possible to use fewer than three rungs, provided that at least one rung is used. The two stiles 4,6 are hingingly attached at 18,20 to an external structure. In this case the external structure may be a bunk 14 in a truck cab but is preferably a sliderail 16 attached to a bunk 14 in a truck cab. The sliderail 16 may be attached immovably or movably to the bunk 14. In this way the stiles 4,6 will be attached hingingly at 18,20 directly to an external structure 16. Having the sliderail 16 attached movably to the bunk 14 makes it possible for the sliderail 16, and hence the retracted ladder 2, to be insertable in a recess of the bunk 14 in its retracted storage position whereby the ladder 2 can be completely out of the way when not in use. For example, the recess may be provided in the underpart of the bunk and be adapted so that the ladder in the retracted position does not protrude downwards from the surface of the underpart.

The stiles 4,6 are attached hingingly to the external structure 16 and are also connected to one another via the three rungs 8,10,12 in such a way that the ladder 2 can be retracted by moving the stiles 4,6 towards one another, which means that the ladder 2 is at least pivotable in such a way as to alter the relative position of the first stile 4 with respect to the second stile 6. It is also possible to arrange the hinged connections 18,20 to the external structure 16 in such a way that the ladder 2 can be pivoted in other directions, e.g. in a direction perpendicular to the longitudinal axes of both the stiles 4,6 and the rungs 8, 10, 12 without altering the relative position of the first stile 4 with respect to the second stile 6.

The stiles 4,6 may be attached hingingly to an external structure at any appropriate point desired which makes the aforesaid retraction movement of the stiles 4,6 possible, i.e. which enables them to be moved towards one another, but they are preferably attached hingingly at 18,20 to an external structure 16 by their upper ends.

The stiles 4,6 are preferably connected hingingly at 18,20 directly to an external structure 16. It is also possible for the stiles to be attached hingingly to an external structure via an intermediate element which will be described in more detail below. As mentioned, the external structure may, for example, be a sliderail 16. In that case the two stiles 4,6 are attached movably to the sliderail 16, which means that the fastening points 18,20 for the stiles 4,6 on the external structure 16 are movable, and preferably movable steplessly. It is also conceivable to make the attachment of the stiles 4,6 movable or relocatable in a number of steps, e.g. by having on the bunk 14 several fasteners between which the stiles 4,6 can be moved step by step.

The at least one rung 8,10,12 is substantially perpendicular to the stiles 4,6 when the ladder 2 is in its extended position of use. When the ladder 2 is in its extended position of use, the first stile 4 still extends down from the bunk 14 to the cab floor 22. According to the preferred embodiment, the second stile 6 is shorter than the first stile 4 and still extends down from the bunk 14 towards the cab floor 22 but without reaching the floor 22. In this way, space is also saved when the ladder 2 is in its extended position of use, since it is possible, for example, for a refrigerator to be situated in the space thus freed in the truck cab. It is nevertheless possible to arrange the second stile 6 in the same manner, and for it to be of the same length, as the first stile 4 if this saving of space is not necessary.

Figure 2 depicts a collapsible ladder 2 according to Figure 1 in a partly extended position, as seen from in front. The ladder 2 is retracted by pivoting the stiles 4,6 relative to the sliderail 16 and hence moving the stiles 4,6 towards one another. As the stiles 4,6 are preferably movably fastened at 18,20 to the sliderail 16 by their upper ends, the fastening points 18,20 for the stiles 4,6 on the sliderail 16 can move sideways (to the left in the case of Figure 1) at the same time as the ladder 2 is retracted. The ladder 2 can thus be retracted by taking hold of, for example, a stile 4 and moving it substantially straight up so that the ladder 2 retracts while said fastening points 18,20 move sideways. This is advantageous in cases where the space for manoeuvring the ladder 2 is limited, e.g. where the ladder 2 is situated behind and between two truck seats. The at least one rung 8,10,12 is substantially parallel to the stiles 4,6 when the ladder 2 is in its retracted storage position. Figure 3 depicts schematically a collapsible ladder 2 according to Figure 1 in the fully retracted storage position, as seen from above.

The ladder 2 is provided with a locking arrangement 24 whereby the ladder 2 can be locked firmly in its retracted storage position. The locking arrangement with advantage takes the form of a spring-loaded snaplock whereby two lock prongs automatically spring in and then out, thus locking the ladder when the ladder is pushed up against the bunk. The ladder is released by pulling a handle on the locking arrangement so that the locking prongs are drawn in and the ladder released. Other types of locking arrangement are also conceivable, e.g. a simple hasp.

Figure 4 depicts a cross-section IV-IV from Fig. 3 of a collapsible ladder 2 in the fully retracted storage position. The stiles 4,6 and the rungs 8,10,12 may have a U-shaped cross-section, but according to the preferred embodiment the first stile 4 is tubular and has an outer first diameter, the at least one rung 8,10,12 takes the form of a tube cut lengthways along the middle and has an inner second diameter and an outer third diameter and the second stile 6 takes the form of a tube cut lengthways along the middle and has an inner fourth diameter, whereby the second diameter is larger than the first diameter but smaller than the third diameter, and the fourth diameter is larger than the third diameter. In this way the stiles 4,6 and the rungs 8,10,12 fit into one another with their cross-sections placed against one another as above when the ladder 2 is retracted, which means that the ladder 2 is very compact in the retracted position.

Figure 5 depicts schematically in perspective view a retraction mechanism of a collapsible ladder 2 according to a first preferred embodiment. The first stile 4 and the second stile 6 are respectively arranged for movement in a conventional manner on the sliderail 16 (not depicted) via four slide elements 26,28,30,32 arranged on the stiles. A control rod 34 is arranged hingingly but not movably via its one end 36 on the first stile 4 and hingingly but not movably via its other end 38 on the sliderail 16. When the ladder 2 is being retracted or extended, the control rod 34 will thus control the sideways movement of the ladder 2 along the sliderail 16. When the locking arrangement 24 opens, the ladder 2 extends downwards automatically under the influence of gravity with a gentle and retarded movement due to the ladder 2 being provided with a gas damper 40 arranged between the stiles 4,6.

Figure 6 depicts schematically a collapsible ladder 2 according to another embodiment of the invention in the fully extended position of use, as seen from above. As mentioned previously, the stiles are preferably attached hingingly directly to an external structure. According to this second embodiment, however, the stiles 4,6 are attached hingingly at 44 to an external structure 16 via an intermediate element 42 such as, for example, a further rung 42 attached hingingly at 9,11 to the stiles 4,6 in the same way as the other rungs 8,10,12, but situated, for example, at the upper ends of the stiles 4,6. This rung 42 is then itself attached to an external structure 16 at a fastening point 44. In this case the external structure may be a bunk 14 in a truck cab, but is preferably a sliderail 16 attached to a bunk 14 in a truck cab. The sliderail 16 may be attached immovably or movably to the bunk 14. In this way the stiles 4,6 will be attached hingingly at 9,11,44 indirectly to an external structure 16. Having the sliderail 16 attached movably to the bunk 14 means that the ladder 2 can be made insertable into the bunk 14 in its retracted storage position, thereby putting the ladder 2 completely out of the way when not in use.

As mentioned above, the ladder may be fitted in association with a bunk in a truck cab. In addition to this preferred application of the ladder, it is possible to arrange a ladder according to the invention in all applications where it is desired to store a ladder in such a way that it occupies the least amount of space and is not in the way when not in use. Examples include on the outside of the cab wall of a truck, on a boat, on a house, on a loading bay and on a household bunk bed.

Claims

1. A collapsible ladder (2) comprising a first stile (4), a second stile (6) arranged substantially parallel with the first stile (4), and at least one rung (8,10,12) attached hingingly (at 9,11) to each of the stiles (4,6), whereby the two stiles (4,6) are connected hingingly (at 18,20) to a sliderail (16) on which the fastening points (18,20) for the stiles (4,6) are steplessly movable, characterised in that one end (36) of a control rod (34) is arranged hingingly but not movably on the first stile (4) and its other end (38) is arranged hingingly but not movably on the sliderail (16).

2. A collapsible ladder according to claim 1, characterised in that the ladder (2) is at least pivotable in such a way as to alter the relative position of the first stile (4) with respect to the second stile (6).

3. A collapsible ladder according to either of claims 1 or 2, characterised in that the stiles (4,6) have their upper ends attached hingingly (at 18,20) to an external structure (16).

4. A collapsible ladder according to any one of claims 1 to 3, characterised in that the stiles (4,6) are attached hingingly (at 44) to an external structure (16) via an intermediate element (42).

5. A collapsible ladder according to claim 4, characterised in that the intermediate element is a rung (42).

6. A collapsible ladder according to any one of claims 1 to 5, characterised in that the fastening points (18,20) for the stiles (4,6) on the external structure (16) are movable.

7. A collapsible ladder according to any one of claims 1 to 6, characterised in that at least one rung (8,10,12) is substantially perpendicular to the stiles (4,6) when the ladder (2) is in its extended position of use.

8. A collapsible ladder according to any one of claims 1 to 7, characterised in that at least one rung (8,10,12) is substantially parallel with the stiles (4,6) when the ladder (2) is in its retracted storage position.

9. A collapsible ladder according to any one of claims 1 to 8, characterised in that the first stile (4) is tubular and has an outer first diameter, the at least one rung (8,10,12) takes the form of a tube cut lengthwise along the middle and has an inner second diameter and an outer third diameter, and the second stile (6) takes the form of a tube cut lengthwise along the middle and has an inner fourth diameter, whereby the second diameter is larger than the first diameter but smaller than the third diameter, and the fourth diameter is larger than the third diameter.

10. A collapsible ladder according to any one of claims 1 to 9, characterised in that the second stile (6) is shorter than the first stile (4).

11. A collapsible ladder according to any one of claims 1 to 10, characterised in that the ladder (2) is provided with a locking arrangement (24) whereby the ladder (2) can be locked immovably in its retracted storage position.

12. A collapsible ladder according to any one of claims 1 to 11, characterised in that the ladder (2) is provided with a gas damper (40).

13. A collapsible ladder according to any one of claims 1 to 12, characterised in that the ladder (2) can be fitted in association with a bunk (14) in a truck cab.

14. A collapsible ladder according to claim 13, characterised in that the ladder (2) is insertable in the bunk (14) in its retracted storage position.