Patent Description:
As known, ladders of various types (fixed, retractable, foldable) are used to gain access to the cargo compartment platform of industrial vehicles, which can be normally folded and stowed under the vehicle platform when not in use. When necessary, said ladders are extracted and/or folded so as to allow access to the respective steps.

Obviously, the ladders must be lightweight, convenient to extract and retract, as well as cost-effective to make and assemble.

Moreover, such ladders must have highly small encumbrances when they are stowed in a retracted condition, otherwise they would affect the usable volume of the cargo compartment.

Moreover, when stowed in the retracted condition, such ladders must not vibrate or move excessively, to avoid causing annoying noises while the vehicle is traveling.

Currently, the market does not have solutions that can fully meet all the needs listed above. Solutions according to the preamble of claim <NUM> are disclosed by <CIT>. <CIT> shows a further telescoping ladder assembly.

The need is thus felt to solve the drawbacks and limitations mentioned above with reference to the prior art.

Such needs are met by a foldable ladder according to claim <NUM> and by an industrial vehicle according to claim <NUM>.

Further features and advantages of the present invention will be more comprehensible from the following description of preferred embodiments thereof, given by way of non-limiting examples, in which:.

The elements or parts of elements common to the embodiments described hereafter will be indicated using the same reference numerals.

With reference to the aforesaid figures, reference numeral <NUM> indicates as whole a foldable ladder, in particular for an industrial vehicle <NUM>.

In particular, the industrial vehicle <NUM> comprises a platform <NUM> having an upper face <NUM>, which defines a climbing plane for a cargo compartment <NUM>, and a lower face <NUM>, opposite to said upper face <NUM>. As described in greater detail below, the ladder <NUM> is preferably fixed to the platform <NUM> of the vehicle <NUM>, at the lower face <NUM> thereof. The ladder <NUM> is usually employed to allow a user to climb onto the vehicle platform starting from the walking surface on which the tires of the vehicle typically rest.

The foldable ladder <NUM> comprises an interface frame <NUM> comprising a pair of tracks <NUM> associable with the platform <NUM> of the vehicle <NUM>, preferably on the side of said lower face <NUM>. Said tracks <NUM> extend along a main longitudinal direction Y-Y. In the assembly configuration, said tracks <NUM> are parallel to the lower face <NUM> of the platform <NUM>. The tracks <NUM> can be connected to each other by one or more crossbars or not.

The ladder <NUM> further comprises a summit portion <NUM> slidingly housed in said interface frame <NUM>, along said main longitudinal direction Y- Y, provided with a pair of rails <NUM> at least partially sliding on said tracks <NUM>.

In particular, the rails <NUM> of the summit portion <NUM> are parallel to said tracks <NUM>.

For example, said tracks <NUM> comprise longitudinal slots <NUM> and the rails <NUM> comprise guide pins <NUM> slidingly associated in said longitudinal slots <NUM> so as to slide parallel to said main longitudinal direction Y-Y.

The ladder <NUM> comprises a first climbing element <NUM>, provided with uprights <NUM> and a first step <NUM>.

The first climbing element <NUM> is hinged to said summit portion <NUM> at first transverse hinges <NUM>, directed along a transverse direction X-X perpendicular to the main longitudinal direction Y-Y. Preferably, said first step <NUM> is provided with an extraction handle <NUM>.

According to a possible embodiment (<FIG>), the summit portion <NUM> comprises a support platform <NUM> which transversely connects said rails <NUM> on the side of the first climbing element <NUM>.

According to a further embodiment (<FIG>), the summit portion <NUM> is devoid of platform and is provided with a front beam <NUM> which transversely connects said rails <NUM> on the side of the first climbing element <NUM>. Further constructional variations are possible with an increasing number of steps and with/without a platform.

The ladder <NUM> further comprises a second climbing element <NUM>, provided with uprights <NUM> and a second step <NUM>, and hinged to said first climbing element <NUM> at second transverse hinges <NUM>, directed parallel to said transverse direction X-X.

Advantageously, the second climbing element <NUM> is foldable on said first climbing element <NUM> on a front access or climbing side of said steps <NUM>, <NUM>, so as to switch from an opening configuration, in which the uprights <NUM> of the second climbing element <NUM> are arranged parallel and adjacent to the uprights <NUM> of the first step <NUM>, to a closing configuration, in which the uprights <NUM> of the second climbing element <NUM> are arranged paired and superimposed on the uprights <NUM> of the first climbing element <NUM>.

According to a possible embodiment, said uprights <NUM> and said steps <NUM>,<NUM> of the first climbing element <NUM> and the second climbing element <NUM> are configured so that, in the closing configuration, they fall within an encumbrance or transverse distance <NUM> of the tracks <NUM> of the interface frame <NUM>, measured parallel to said transverse direction X-X.

According to a possible embodiment, said uprights <NUM> and said steps <NUM>,<NUM> of the first climbing element <NUM> and the second climbing element <NUM> are configured so that, in the closing configuration, they fall within a vertical encumbrance <NUM> of the tracks <NUM> of the interface frame <NUM>, measured perpendicular to said transverse direction X-X and to said main longitudinal direction Y-Y.

According to a possible embodiment, said uprights <NUM> of the first climbing element <NUM> and the second climbing element <NUM> have a longitudinal length <NUM>, parallel to said main longitudinal direction Y-Y, less than or equal to a longitudinal extension <NUM> of said rails <NUM> and/or said tracks <NUM> of the interface frame <NUM>.

The rails <NUM> of the summit portion <NUM>, at the front ends <NUM>, are provided with front gaps <NUM> adapted to abut against respective transverse pins <NUM> associated with the uprights <NUM> of the first climbing element <NUM> (in said closing configuration).

According to a possible embodiment, said tracks <NUM> comprise front seats <NUM> having an 'L' shape and provided with a longitudinal upper section <NUM> and a vertical lower section <NUM>. Said front seats <NUM> are configured to receive said transverse pins <NUM> and lock them in said vertical lower section <NUM>, in a closing configuration of the ladder <NUM>. In particular, said vertical lower section <NUM> has a longitudinal undercut <NUM> which opposes the extraction of the first climbing element <NUM> in the main longitudinal direction Y-Y.

According to a possible embodiment, at least one central belt spring <NUM> is fixed to said summit portion <NUM>, adapted to achieve an undercut lock with said second step <NUM>, in said closing configuration. Said central belt spring <NUM> ensures the function of a second safety lock, with a snap lock perceptible clearly and distinctly by the user both mechanically (by snapping) and audibly ("click effect"). This minimizes the risk of a ladder being mistakenly left not fully closed on the vehicle before resuming driving.

For example, said central belt spring <NUM> has a 'V' shape, so that a vertex <NUM> of said 'V' forms said undercut.

For example, said central belt spring <NUM> is fixed cantilevered to a rear beam <NUM> of the summit portion <NUM>, opposite to the first climbing element <NUM>.

According to a possible embodiment, lateral locking springs <NUM> are provided, integral and cantilevered with respect to rear ends <NUM> of the rails <NUM> of the summit portion <NUM>, adapted to achieve an undercut coupling between the rails <NUM> and the tracks <NUM> of the interface frame <NUM>, in said closing configuration.

For example, said lateral locking springs <NUM> are belt springs with a 'V' shape, so that a vertex <NUM> of said 'V' achieves said undercut coupling.

According to a possible embodiment, the steps <NUM>,<NUM> are fixed to the uprights <NUM> of the corresponding climbing elements <NUM>,<NUM> by means of rivets.

Preferably, the steps <NUM>, <NUM> are fixed to the uprights <NUM> of the corresponding climbing elements <NUM>,<NUM> by means of rear rivets (instead of lateral ones).

In particular, the first and second steps <NUM> and <NUM> are fixed to the uprights <NUM> of the corresponding climbing elements <NUM>, <NUM> by means of countersunk rivets. The 'L'-shaped profiles <NUM> have one long side and one short side. Countersunk holes required for the insertion of the rivets, adapted to fix the steps themselves, are present outside the short side. Using rear rivets (instead of lateral rivets) allows the assembly consisting of step <NUM> and side uprights <NUM> to be rotate on the second transverse hinges <NUM> and be housed within the uprights <NUM>, without interfering with the first step <NUM>.

According to a possible embodiment, the tracks <NUM>, the summit portion <NUM>, and said climbing elements <NUM>, <NUM> are made of magnelis®. In particular, using pre-galvanized steel, there is no need for any anti-rust treatment after processing.

The operation of a foldable ladder according to the present invention will now be described.

For completeness, reference will be made to the figures of both embodiments of the present invention, which have an entirely similar opening/closing sequence.

In particular, we will start with the retracted or folded configuration in which the ladder is folded underneath the platform of the cargo compartment of the vehicle.

In greater detail (<FIG> and <FIG>), in the retracted or closing configuration, the second climbing element <NUM> is superimposed and folded over the first climbing element <NUM>; both climbing elements <NUM>,<NUM> are inserted longitudinally into the summit portion <NUM> which, in turn, is housed between the tracks <NUM> of the interface frame <NUM>.

The locking configuration is ensured by the fact that the transverse pins <NUM> associated with the uprights <NUM> of the first climbing element <NUM> are housed and locked in the front seats <NUM> of the tracks <NUM>.

Moreover, by virtue of the 'L' configuration of the frontal seats <NUM>, the transverse pins <NUM> are housed in the vertical lower section <NUM>, which has the longitudinal undercut <NUM> opposing the extraction of the first climbing element <NUM> to operate the opening of the ladder <NUM>.

Moreover, in the closing configuration, the summit portion <NUM> bears on the folded assembly consisting of the first climbing element <NUM> and the second climbing element <NUM> with its own weight. Here, the summit portion biases the transverse pins <NUM> to remain housed in the vertical lower section <NUM>, so that they are subjected to the action of the longitudinal undercut <NUM> which opposes the extraction or opening of the ladder <NUM>.

Moreover, in the retracted or closing configuration, the combined bias of the central belt spring <NUM> and/or the lateral locking springs <NUM> gives a further safety and locking element of ladder <NUM>.

To open the ladder <NUM>, the operator must then grasp the extraction handle <NUM> with which to first lift the first climbing element <NUM> to disengage the transverse pins <NUM> from the vertical lower sections <NUM> of the front seats, while also overcoming the weight applied by the summit portion <NUM>.

Moreover, the operator must overcome the spring bias applied by the central belt spring <NUM> and/or the lateral locking springs <NUM>.

The first climbing element <NUM> is then extracted longitudinally (<FIG> and <FIG>) and tilted downwards (<FIG> and <FIG>).

At this point, the second climbing element <NUM> can be rotated by <NUM> degrees so as to form a single contiguous climbing ramp between the first climbing element <NUM> and the second climbing element <NUM> (<FIG> and <FIG>).

Obviously, for the next closing step, it will be sufficient to reverse the order of the steps described above.

As can be appreciated from the description above, the present invention allows overcoming the drawbacks presented in the prior art.

In particular, the present invention allows for a drastic reduction in encumbrance by virtue of the fact that the second element is not rigid, but rather hinged and foldable/tiltable on the first element. The longitudinal extension of the compartment that must accommodate the ladder in a retracted configuration is thus halved.

In addition to the drastic reduction in encumbrance, the solution brings benefits in terms of logistics by virtue of the modularity in creating <NUM>-step/<NUM>-step/<NUM>-step variants with or without a platform.

Advantageously, the ladder assembly system with screws and bolts, countersunk rivets for fixed parts, provides for the total absence of welding, unlike the prior art solutions; therefore, on the one hand, assembly costs are reduced, and on the other hand, the risks of dubious finishes and possible rust/crack triggers are reduced.

The use of magnelis® material allows achieving a self-healing effect in case of scratches (e.g., in contact areas, slots, creeps), and does not require the use of specific surface treatments which would increase production costs.

The interface frame with the platform of the vehicle is also simplified in that it comprises only two rails instead of the small frames of the prior art solutions; a further simplification of costs and respective logistics of the ladder components is thus obtained.

The double pin-cradle and platform locking system, by means of the front seats of the rails having an 'L' shape, which by gravity is interlocked in the cradle and locks the ladder together with the bias of the belt springs, ensures a stable and secure fixing of the ladder in the retracted position; the possibility of vibrations and disturbing noises of the parts of the ladder, while the vehicle is traveling, is thus eliminated. In particular, the second spring latch, by virtue of the aforementioned "mechanical lock" and "audible click" effect, also ensures that the risk of it being forgotten not fully closed is minimized or eliminated. Indeed, the user will have learned not to consider it closed until he/she clearly feel the effects mentioned above.

Advantageously, the step is secured to the corresponding climbing element by means of rear rivets instead of lateral rivets; the tilting part is thus avoided from being capable of rotating while the operator climbs up. In particular, as mentioned above, using rear rivets (instead of lateral rivets) allows the assembly consisting of step <NUM> and side uprights <NUM> to rotate on the second transverse hinges <NUM> and to be housed within the uprights <NUM>, without interfering with the first step <NUM>.

In order to meet contingent, specific needs, those skilled in the art may make several changes and variations to the solutions described above.

Claim 1:
Foldable ladder (<NUM>) comprising:
- an interface frame (<NUM>) comprising a pair of tracks (<NUM>) associable with a platform (<NUM>) of a vehicle (<NUM>), said tracks (<NUM>) extending along a main longitudinal direction (X-X),
- a summit portion (<NUM>) slidably housed in said interface frame (<NUM>), along said main longitudinal direction (X-X), provided with a pair of rails (<NUM>) at least partially sliding on said tracks (<NUM>),
- a first climbing element (<NUM>), provided with uprights (<NUM>) and a first step (<NUM>), and hinged to said summit portion (<NUM>) at first transverse hinges (<NUM>), directed along a transverse direction (X-X) perpendicular to the main longitudinal direction (Y-Y),
- a second climbing element (<NUM>), provided with uprights (<NUM>) and a second step (<NUM>), and hinged to said first climbing element (<NUM>) at second transverse hinges (<NUM>), directed parallel to said transverse direction (X-X),
- the second climbing element (<NUM>) being foldable on said first climbing element (<NUM>) from a front access or climbing side to said steps (<NUM>,<NUM>), so as to pass from an opening configuration, in which the uprights (<NUM>) of the second climbing element (<NUM>) are arranged parallel and adjacent to the uprights (<NUM>) of the first step (<NUM>), to a closing configuration in which the uprights (<NUM>) of the second climbing element (<NUM>) are arranged paired and superimposed on the uprights (<NUM>) of the first climbing element (<NUM>),
characterized in that
the rails (<NUM>) of the summit portion (<NUM>), at the front ends (<NUM>), are provided with front gaps (<NUM>) adapted to make an abutment with respective transverse pins (<NUM>) associated with the uprights (<NUM>) of the first climbing element (<NUM>).