Patent Description:
Industrial vehicles like trucks are equipped with boarding steps to help the truck driver, or passenger, get into the cabin of the truck. Usually, a first boarding step is installed on the side of the truck, between the front wheel and the front bumper, approximately at the height of the front bumper. This first boarding step may be quite far above ground level, and it therefore common to implement a second step closer to the ground. On certain off-roads vehicles such as mining trucks, this second step may be located within the area included in the approach angle of the vehicle. Therefore, this second step can easily be damaged by stones or various obstacles when the vehicle is driven on rough surfaces. In addition, the second step can easily rust because it is very often covered by mud. In order to avoid these inconveniences that require maintenance and servicing, these second side-steps are often dismantled and removed by the truck owner when receiving a brand-new truck. Not having this second step available is an inconvenience for the short drivers, or passengers, and can be a hazard. Document <CIT> discloses a foldable step assembly with two horizontal steps that are interconnected via a linkage mechanism, and whose opening is controlled by a linear pneumatic actuator controlled from a control unit and various sensors.

There is a need to have a step assembly that can be available when the driver or a passenger needs to enter or leave the vehicle, and which doesn't get damaged when the vehicle is driven in rough off-road conditions.

To this end, it is proposed a step assembly for helping a user entering a cabin of an industrial vehicle as defined by the features of claim <NUM>.

The industrial vehicle comprises one or several fixed steps. When several fixed steps are present, the fixed steps are staggered along the side of the vehicle, next to the entry door. The driver or the passenger may climb over the different fixed steps to access the cabin. When it is deployed, the mobile step member stands closer to the ground than the first fixed step, so the driver can access more easily to the cabin. When the industrial vehicle is driven, the mobile step member is in the stowed position so that the mobile step member is not in the approach angle zone. The risk of damaging the mobile step member when driving over rough obstacles is eliminated.

The following features can optionally be implemented, separately or in combination one with the others:.

According to the invention, the actuation member is an actuation cable.

An actuation cable makes a reliable mechanical link that can take different shapes and thus can easily be adapted to various configurations.

According to an embodiment, the step assembly comprises an elastic member configured for moving the mobile step member from the deployed position to the stowed position in response to a closing of the entry door.

Once the driver has entered the cabin and closes his door, the elastic member brings back the mobile step member into its stowed position. No action from the driver is necessary.

In an embodiment, the elastic member is a return spring.

In an embodiment, the elastic member may be a coil spring.

In an embodiment, the elastic member may be a torsion bar.

According to an embodiment of the step assembly, the check link is configured for stopping the entry door in a predetermined position, the predetermined stopping position being an intermediate position between a closed position and a fully opened position.

Using the check link of the door to pull the actuation member allows an actuation of the step assembly that limits the number of additional parts to be fitted.

According to an embodiment of the step assembly, a rate of increase of a position of the mobile step member is proportional to a rate of increase of an opening degree of the entry door, at least for a fraction of a movement stroke from the stowed position to the deployed position.

In an embodiment of the step assembly, the mobile step member reaches the deployed position for an opening degree of the entry door inferior to a maximum opening degree of the entry door.

In an embodiment, the mobile step member leaves the stowed position for an opening degree of the entry door superior to a minimum opening degree of the entry door.

The opening degree of the entry door for which the mobile step member leaves the stowed position can be the closed position of the entry door.

The opening degree of the entry door for which the mobile step member leaves the stowed position can be a position of the entry door different from the closed position of the entry door.

The predetermined stopping position is selected among a set of stopping positions.

In an embodiment, the first rotation axis is horizontal when the step assembly is installed in the vehicle.

According to the invention, the mobile step member comprises:.

In an embodiment, the fourth rotation axis is horizontal.

In an embodiment, the fourth rotation axis is parallel to a transversal axis of the vehicle when the step assembly is installed in the industrial vehicle.

A pivot axis of the first linkage relatively to the stepping board defines a fifth rotation axis.

A pivot axis of the second linkage relatively to the stepping board defines a sixth rotation axis.

In an embodiment, the fourth rotation axis, the fifth rotation axis and the sixth rotation axis are parallel. The first linkage, a side of the stepping board, and the second linkage define three consecutive sides of a deformable parallelogram.

In an embodiment, the second end of the first linkage is attached to a first corner of the stepping board.

In an embodiment, the first end of the second linkage is attached to a second corner of the stepping board.

The first linkage and the second linkage may have an equal length.

The disclosure also refers to a truck comprising a step assembly as described earlier.

In an embodiment, the mobile step member is configured to be located in the approach angle area when the step assembly is in the deployed position and the mobile step member is configured to be located out of the approach angle area when the step assembly is in the stowed position.

In order to make the figures easier to read, the various elements are not necessarily represented to scale. In these figures, identical elements receive the same reference number. Certain elements or parameters can be indexed, that is to say designated for example by 'first element' or second element, or first parameter and second parameter, etc. The purpose of this indexing is to differentiate elements or parameters that are similar, but not identical. This indexing does not imply a priority of one element, or one parameter over another, and their names can be interchanged. When it is mentioned that a subsystem comprises a given element, the presence of other elements in this subsystem is not excluded.

<FIG> illustrates an industrial vehicle such as a truck <NUM>. The truck <NUM> comprises a cabin <NUM>. An entry door <NUM> provides access to and exit from the cabin <NUM>. One or several fixed steps <NUM> are staggered along the side of the vehicle <NUM>, next to the entry door <NUM>. The steps provide a support at an intermediate height between the level of the ground G and the level of the sill <NUM> of the entry door <NUM>. When a user intends getting in or out of the truck, he can walk on the steps <NUM> to safely enter or exit the cabin <NUM>.

The dotted line L, which is tangent to the bottom of the front bumper <NUM> and to the front wheel <NUM>, defines the approach angle a of the truck <NUM>. When the truck is driven off-road, for example on construction sites or mines, any stone or obstacle located in zone <NUM> comprised between the ground level G and the dotted line L may be climbed over without impacting the structure of the truck. The fixed step <NUM>, standing higher than the dotted line L, and well out of the approach angle zone, is unlikely to be hit by any obstacle.

On the other hand, any object hanging from the truck <NUM> and located in the area <NUM> comprised between the ground level G and the dotted line L is likely to be hit and damaged by the stones or obstacles that the truck is driven over. Therefore, an additional fixed step cannot be fitted in the area located below the dotted line L, since it will be quickly damaged when the truck is be driven in harsh conditions. As the ground clearance of such a truck may be quite high, having an additional step located at an intermediate level between the ground and the fixed step <NUM> would be useful.

The truck <NUM> comprises a step assembly <NUM> that will be detailed below.

The present disclosure proposes a step assembly <NUM> for helping a user entering a cabin <NUM> of an industrial vehicle <NUM>,.

As illustrated in <FIG>, the mobile step member <NUM> is configured to be located in the approach angle area <NUM> when the step assembly is in the deployed position E. The mobile step member <NUM> is configured to be located out of the approach angle area <NUM> when the step assembly is in the stowed position S. The ground clearance of the truck is larger when the step assembly is in the stowed position S than when the step assembly is in the deployed position E.

When the step assembly <NUM> is deployed, the mobile step member <NUM> stands closer to the ground than the first fixed step <NUM>, therefore the driver can access more easily to the cabin <NUM>. When the industrial vehicle <NUM> is driven, the mobile step member <NUM> is in the stowed position S so that the mobile step member <NUM> is not in the approach angle zone. The risk of damaging the mobile step member <NUM> when driving over rough obstacles is eliminated, while providing additional support compared to the fixed steps <NUM>.

The entry door <NUM> is configured for swiveling between a closed position C and a fully opened position O. The entry door is fixed to the frame of the cabin by several hinges, not represented.

In the deployed position E of the mobile step member <NUM>, a user can step on the mobile step member <NUM>. The mobile step member <NUM> comprises a stepping board <NUM> that can receive the foot on the user. The user may transfer its weight on the stepping board <NUM>.

According to the invention, and as illustrated here, the actuation member <NUM> is an actuation cable <NUM>. An actuation cable makes a reliable mechanical link that can take different shapes and thus can easily be adapted to various configurations.

As detailed on <FIG> and <FIG>, the check link <NUM> has an elongated shape similar to a rod. Functionally, the check link <NUM> is a linking rod. The check link <NUM> comprises a first end <NUM> configured to be linked to the entry door <NUM> of the cabin, and a second end <NUM> linked to a first end of the actuation cable <NUM>. The check link <NUM> is pivotably linked to the entry door <NUM> of the cabin. For this, the first end <NUM> of check link <NUM> is fixed to the entry door <NUM> by a pivot pin. A rotation of the check link <NUM> relatively the entry door <NUM> is allowed. A translation motion of the check link <NUM> relatively the entry door <NUM> is blocked. A section of the check-link <NUM> passes through a bracket <NUM> fixed to the frame of the cabin <NUM>. The actuation cable is contained, near the bracket <NUM>, in a wire holder <NUM>. The check link <NUM> may be made of sheet metal. The check link <NUM> may be cast. The check link <NUM> is horizontal when it is installed in the entry door <NUM> of the industrial vehicle <NUM>.

The mobile step member <NUM> can be made of sheet metal. For example aluminum, magnesium can be used. The mobile step member <NUM> may also be made of plastic, for example injected plastic reinforced with glass fibers.

According to an embodiment, the step assembly comprises an elastic member <NUM> configured for moving the mobile step member <NUM> from the deployed position E to the stowed position S in response to a closing of the entry door <NUM>. Once the driver has entered the cabin and closes his door, the elastic member <NUM> brings back the mobile step member <NUM> into its stowed position S. No action from the driver is necessary. The step assembly is automatically stowed before the vehicle is actually driven. There's no risk of forgetting to stow the step assembly before driving since no action is required.

The actuation cable <NUM> operates the mobile step member <NUM> against the biaising action of the elastic member <NUM>. In an embodiment, the elastic member <NUM> is a return spring. For example, the elastic member <NUM> may be a coil spring. Alternatively, the elastic member <NUM> may be a torsion bar.

According to an embodiment of the step assembly, the check link <NUM> is configured for stopping the entry door <NUM> in a predetermined position, the predetermined stopping position being an intermediate position between a closed position C and a fully opened position O. Using the check link of the entry door to pull the actuation member allows an actuation of the step assembly <NUM> that limits the number of additional parts to be fitted.

The predetermined stopping position is selected among a set of stopping positions. The set of stopping positions may comprise three stopping positions.

As detailed on <FIG>, the check link <NUM> comprises a friction area <NUM> configured to be pressed by elastic pegs <NUM>. The friction area comprises a flat portion <NUM> and a thinned portion <NUM>. The transition between the flat portion <NUM> and the thinned portion <NUM> is made by a slope <NUM>. When the check link <NUM> is moved, the elastic pegs <NUM> slides over the friction area <NUM>. The stopping position is obtained when an elastic peg <NUM> engages into the thinned portion <NUM>. Additional effort is then required to force the pegs <NUM> moving over the slope <NUM> until it reaches another flat portion <NUM>. The tension of the elastic pegs <NUM> and the angle of the transition slopes <NUM> are designed to obtain the targeted resistance to maintain the entry door <NUM> in a stable position without requiring an excessive effort to then overcome a stopping position. The number of stopping positions is determined by the number of thinned portions <NUM> incorporated in the check link <NUM>.

<FIG> illustrates the relationship between the position of the mobile step member <NUM>, in vertical axis, versus the opening degree of the entry door <NUM> in horizontal axis. Opening degree is a term equivalent to angular position of the entry door. The closed position C of the entry door <NUM> is obtained for an opening degree equal to <NUM>. The fully opened position O of the entry door <NUM> is obtained for the opening degree o4. Similarly, the stowed position S is corresponding to position O on the vertical axis, and the deployed position E is corresponding to the maximum of the curve.

On the example of part B of <FIG>, the mobile step member <NUM> reaches the deployed position E for an opening degree of the entry door <NUM> inferior to a maximum opening degree of the entry door <NUM>. On this example, the fully deployed position E is obtained when the opening degree of entry door <NUM> reaches the degree o3, and remains constant until the entry door <NUM> is fully opened, corresponding to the opening degree o4.

The mobile step member <NUM> can leave the stowed position S for an opening degree a of the entry door <NUM> superior to a minimum opening degree of the entry door <NUM>. In the embodiment corresponding to part B of <FIG>, the opening degree of the entry door <NUM> for which the mobile step member <NUM> leaves the stowed position S is a position o1 of the entry door <NUM>, which is different from the closed position C. In other words, the deployment of the step assembly <NUM> begins only once the opening of the entry door <NUM> has already been initiated, and the entry door <NUM> has already been opened by a certain amount. This configuration makes the initial opening of the door easier, and the deployment of the step assembly can make use of the momentum built during the initial phase in which the entry door is free. Deployment of the mobile step member <NUM> starts when the opening degree of the entry door <NUM> reaches the value marked o1 on part B of <FIG>.

The minimum opening degree of the entry door <NUM> for which the mobile step member <NUM> leaves the stowed position S can be one of the predetermined stopping positions of the entry door <NUM>. These positions are determined by the position of the thinned portions <NUM> along the check link <NUM>.

In an embodiment corresponding to part A of <FIG>, the minimum opening degree of the entry door <NUM> for which the mobile step member <NUM> leaves the stowed position S can be the closed position C of the entry door <NUM>. In that case, the deployment of the mobile step assembly <NUM> begins simultaneously with the opening of the entry door <NUM>.

Several different kinematic systems can be implemented for the actuation of the step assembly <NUM>.

In an example of a step assembly <NUM>, illustrated on <FIG>, the mobile step member <NUM> is configured to slide linearly between the stowed position S and the deployed position E. The mobile step member <NUM> is configured to move vertically when the step assembly is normally installed in the industrial vehicle <NUM>.

The mobile step member <NUM> comprises a stepping board <NUM> and two parallel support arms 7a, 7b extending on each side of the stepping board <NUM>. Each support arm 7a, 7b is configured to slide respectively into a slot 27a, 27b. The slots 27a, 27b guide the translational movement of the corresponding support arm 7a, 7b.

In the example of <FIG>, the stepping board <NUM> has a rectangular shape, and each support arm 7a, 7b joins the stepping board <NUM> substantially in the middle of opposite sides of the stepping board <NUM>. The mobile step member <NUM> and the two parallel support arms 7a, 7b form a rigid assembly.

In this example, one end of the actuation cable <NUM> is attached to a support arm 7a. When the entry door <NUM> is opened, the actuation cable <NUM> is put under tension and the actuation cable <NUM> pulls the mobile step member <NUM> into the deployed position E.

A linear stroke of the mobile step member <NUM> is comprised between <NUM> centimeters and <NUM> centimeters. The stepping board <NUM> may be parallel to a fixed step <NUM> of the cabin <NUM>.

In this example, the stepping board <NUM> is configured to be under the fixed step <NUM> when the mobile step member <NUM> is in the stowed position S, and a vertical distance e between the fixed step <NUM> and the mobile step member <NUM> is comprised between <NUM> centimeter and <NUM> centimeters, as indicated on <FIG>.

<FIG> and <FIG> relate to another example of a step assembly <NUM>. In this example, the mobile step member <NUM> is configured to swivel around a first rotation axis A1 between the stowed position S and the deployed position E.

The first rotation axis A1 is horizontal when the step assembly <NUM> is installed in the vehicle <NUM>. Furthermore, the first rotation axis A1 is parallel to a transversal axis Y of the vehicle <NUM> when the step assembly is installed in the vehicle <NUM>. In a non-represented embodiment, the first rotation axis A1 is parallel to a longitudinal X of the vehicle <NUM> when the step assembly is installed in the vehicle <NUM>.

As represented on <FIG>, the mobile step member <NUM> comprises a stepping board <NUM>' and two parallels support arms 7a', 7b' extending on each side of the stepping board <NUM>' and rigidly linked to the stepping board <NUM>', and each support arm 7a', 7b' is configured to swivel around the first rotation axis A1. The mobile step member <NUM> and the two parallel support arms 7a', 7b' form a rigid assembly. As <FIG> is a side view, support arm 7a' and support arm 7b' appear merged.

The stepping board <NUM> has a rectangular shape, and each support arm 7a', 7b' joins the stepping board <NUM> substantially in consecutive corners <NUM> of the stepping board <NUM>.

An angular stroke of the mobile step member <NUM> may be comprised between <NUM>° and <NUM>°.

As illustrated on <FIG>, the mobile step member <NUM> comprises:.

The first pivot link <NUM> is pulled by the actuation cable <NUM> when the entry door <NUM> is moved from the closed position C to the fully opened position O. The actuation cable <NUM> is attached to the first end <NUM> of the first pivot link <NUM>.

The rotation axis A2 of the first pivot link <NUM> is parallel to the rotation axis A1 of the support arms 7a', 7b'. In other words, the first rotation axis A1 and the second rotation axis A2 are parallel.

The pivot axis of the second pivot link <NUM> relatively to the support arm 7a', 7b' defines a third pivot axis A3. The third pivot axis A3 is parallel to the first rotation axis A1. The pivot axis A3 of the second pivot link <NUM> relatively to the support arm 7a', 7b' is offset respectively to the first rotation axis A1 so that the second pivot link <NUM> can create a rotation torque of the support arm 7a', 7b' with respect to the first rotation axis A1.

When the step assembly <NUM> is installed in the truck <NUM> and the mobile step member <NUM> is in the deployed position E, the first pivot link <NUM> is horizontal and the second pivot link <NUM> is vertical.

In some examples, the step assembly <NUM> comprises a fixed step <NUM> configured to be attached to a bodywork element of the industrial vehicle <NUM>, and the stepping board <NUM> is configured to be adjacent to the fixed step <NUM> when the mobile step member <NUM> is in the stowed position S. The step assembly <NUM> is thus compact when the mobile step member <NUM> is in the stowed position S.

The fixed step <NUM> is located below the entry door <NUM> of the cabin <NUM>. The fixed step <NUM> extends between a front wheel <NUM> of the vehicle <NUM> and a front bumper <NUM> of the vehicle <NUM>.

In an example, illustrated on <FIG>, the stepping board <NUM> is perpendicular to the fixed step <NUM> of the cabin <NUM> when the mobile step member <NUM> is in the stowed position S.

<FIG> refers to the invention. According to the invention, the mobile step member <NUM> comprises:.

The fourth rotation axis A4 is horizontal. The fourth rotation axis A4 is parallel to a transversal axis Y of the vehicle <NUM> when the step assembly is installed in the industrial vehicle <NUM>.

A pivot axis of the first linkage <NUM> relatively to the stepping board <NUM>" defines a fifth rotation axis A5. A pivot axis of the second linkage <NUM> relatively to the stepping board <NUM>" defines a sixth rotation axis A6.

In the third embodiment, the fourth rotation axis A4, the fifth rotation axis A5 and the sixth rotation axis A6 are parallel. The first linkage <NUM>, a side <NUM> of the stepping board <NUM>", and the second linkage <NUM> define three consecutive sides of a deformable parallelogram.

The second end <NUM> of the first linkage <NUM> is attached to a first corner <NUM>" of the stepping board <NUM>". The first end <NUM> of the second linkage <NUM> is attached to a second corner <NUM> of the stepping board <NUM>". A straight line joining the first corner <NUM> and the second corner <NUM> define a side <NUM> of the stepping board <NUM>. The first linkage <NUM> and the second linkage <NUM> may have an equal length.

When the mobile step member <NUM> is in the deployed position E, the first linkage <NUM> and the second linkage <NUM> are parallel. Furthermore, the first linkage <NUM> and the second linkage <NUM> are vertical.

When the mobile step member <NUM> is in the stowed position S, the second linkage <NUM> is horizontal. When the mobile step member <NUM> is in the stowed position S, the first linkage <NUM> is vertical.

When the mobile step member <NUM> is in the stowed position S, an angle h1 between the first linkage <NUM> and the stepping board <NUM>" is comprised between <NUM>° and <NUM>°. When the mobile step member <NUM> is in the stowed position S, an angle h2 between the stepping board <NUM> and the second linkage <NUM> is comprised between <NUM>° and <NUM>°. This configuration is represented on part C of <FIG>.

The first linkage <NUM>, the stepping board <NUM>" and the second linkage <NUM> are neatly stowed and out of the approach angle area <NUM> when the mobile step member <NUM> is in the stowed position S. As with the first two embodiments, the step assembly <NUM> as disclosed provides a support for access to the industrial vehicle, that is deployed only when access is required. The step assembly is protected from the damages of rough driving conditions since it is stowed when the industrial vehicle is driven.

Claim 1:
A step assembly (<NUM>) for helping a user entering a cabin (<NUM>) of an industrial vehicle (<NUM>), the step assembly (<NUM>) comprising:
- a check link (<NUM>) configured to be linked to an entry door (<NUM>) of the cabin (<NUM>),
- an actuation cable (<NUM>),
- a mobile step member (<NUM>) configured to be movable between a stowed position (S) and a deployed position (E),
the actuation cable (<NUM>) linking the mobile step member (<NUM>) and the check link (<NUM>),
in which the mobile step member (<NUM>) is configured to be moved from the stowed position (S) to the deployed position (E) by the actuation cable (<NUM>) in response to an opening of the entry door (<NUM>),
in which the mobile step member (<NUM>) comprises:
- a first linkage (<NUM>),
- a stepping board (<NUM>"),
- a second linkage (<NUM>),
in which a first end (<NUM>) of the first linkage (<NUM>) is linked to the actuation cable (<NUM>) and a second end (<NUM>) of the first linkage (<NUM>) is pivotably connected to the stepping board (<NUM>),
in which a first end (<NUM>) of the second linkage (<NUM>) is pivotably connected to the stepping board (<NUM>) and a second end (<NUM>) of the second linkage (<NUM>) is configured to pivot relatively to a fourth rotation axis (A4).