Patent Description:
In the construction or maintenance of structures such as buildings, vessels, power plants, tanks, smokestacks, and bridges, suspended platforms including work cages have been used for safe and efficient high-rise operations on the wall surfaces. A suspended platform is installed on a rooftop, and has a work cage carrying an operator, which is suspended from the rooftop with lanyards such as wires.

The work cage of the suspended platform carries an operator who performs an operation on the wall surfaces while being lowered from the rooftop by changing the positions of the lanyards wound around the sheaves of endless winders (refer to, for example, Patent Literature <NUM>).

For inspection or maintenance of road bridges or other structures, boom lift vehicles (bridge inspection vehicles) are used. A boom lift vehicle includes an arm mechanism and a work cage installed at the distal end of the arm mechanism, and moves the distal end of the arm mechanism to an intended position in combination with a rotating mechanism, an extension mechanism, and a derricking mechanism installed on the vehicle.

For example, an operator in the work cage of the boom lift vehicle moves the distal end of the arm mechanism to a work position from above the road to allow the operator in the work cage installed at the distal end to perform an operation (refer to, for example, Patent Literature <NUM>).

A boom lift vehicle may be used for inspection or maintenance of structures, such as bridges, with heights of several tens of meters, such as bridge piers. However, the boom lift vehicle cannot access specific areas with the distal end of the arm mechanism that is extended or contracted from above the road, and thus has a limited operating range. In contrast, a suspended platform can use longer lanyards to suspend a work cage for operations in the descending range without limitations. An example hereof is described in <CIT>, disclosing a work vehicle according to the preamble of claim <NUM> including a suspended platform comprising a support frame and a cradle frame or work cage suspended from the support frame. The height of the cradle frame can for example be adjusted by suspension wires. The suspended platform is connected to an adjustable arm which in turn is connected to a mobile base. However, the suspended platform including the work cage suspended from a road cannot access areas above its suspension point, areas at the bottom surface of the road slab, or areas below the bottom surface, and thus cannot perform operations in such areas.

In view of the above circumstances, an objective of the present disclosure is to provide a work vehicle including a suspended platform that is movable to an intended position to perform operations in a wide operating range without limitations.

A work vehicle including a suspended platform according to a first aspect of the present disclosure includes a work cage to carry an operator, an arm mechanism having a distal end, the distal end being movable to an intended position by at least one of a rotating mechanism, an extension mechanism, or a derricking mechanism that are installed on a vehicle body, and the suspended platform including a support post located at the distal end of the arm mechanism and extending vertically, a suspension frame, from which the work cage is suspended, mounted on an upper end of the support post, being located outside the work cage, allowing the operator to perform an operation on a portion above the upper end of the support post, and a lift mechanism configured to raise or lower the work cage to a work position, the work cage being suspended from the suspension frame with a plurality of lanyards. The arm mechanism includes an operation panel that is operable from the work cage at an uppermost stop position and inoperable from the work cage at a raised or lowered position.

Optionally or additionally, the work vehicle may further include a fastening mechanism located between the work cage and the suspension frame to fasten the work cage at an uppermost stop position, and a load detector installed in the suspension frame to detect a fastened state of the work cage at the uppermost stop position based on a load on at least one of the lanyards.

Optionally or additionally, the lift mechanism in the suspended platform may be driven by a battery mounted on the work cage. The work cage may have the battery rechargeable at an uppermost stop position with power from an external power supply.

The support post may include a rotating post that rotates about a vertical axis.

The work vehicle including the suspended platform according to the above aspects of the present disclosure is movable to an intended position to perform operations in a wide operating range without limitations.

A work vehicle including a suspended platform according to an embodiment of the present disclosure will now be described in detail with reference to the accompanying drawings.

As shown in <FIG>, a work vehicle <NUM> including a suspended platform according to one embodiment of the present disclosure includes a work cage <NUM> to carry an operator, and an arm mechanism <NUM>, which has a distal end movable to an intended position by at least one of a rotating mechanism <NUM>, an extension mechanism <NUM>, or a derricking mechanism <NUM> installed on a vehicle body <NUM>. The work vehicle <NUM> includes a suspended platform <NUM>, which includes a support post <NUM>, a suspension frame <NUM>, and lift mechanisms <NUM>. The support post <NUM> is located at the distal end of the arm mechanism <NUM> and extends vertically. The suspension frame <NUM>, from which the work cage <NUM> is suspended, is located at the upper end of the support post <NUM> to allow the operator to perform an operation above the upper end of the support post <NUM>. The lift mechanisms <NUM> raise or lower the work cage <NUM>, suspended from the suspension frame <NUM> with multiple lanyards <NUM>, to a work position.

More specifically, the work vehicle <NUM> including the suspended platform <NUM> according to the present embodiment (hereinafter simply, the work vehicle) includes the suspension frame <NUM>, which allows the suspended platform <NUM> to be suspended from the suspension frame <NUM> with the support post <NUM> at the distal end of the arm mechanism <NUM> installed on the vehicle body <NUM>, and the lift mechanism <NUM>, which raises or lowers the work cage <NUM> suspended from the suspension frame <NUM> with the lanyards <NUM>. The work vehicle <NUM> can freely travel on roads or other surfaces. The work vehicle <NUM> can move the distal end of the arm mechanism <NUM> on the vehicle body <NUM> to an intended position, and can raise or lower the work cage <NUM> suspended from the suspension frame <NUM> at the distal end of the arm mechanism <NUM>. An operator can thus perform an operation in the work cage <NUM> at an intended position within a wide operating range in which the work cage <NUM> is raised or lowered, and also an operation above the suspension frame <NUM> without limitations, and can perform an operation in a wide range, and can perform an operation in a wide operation range.

The work vehicle <NUM> according to the present embodiment is used as, for example, a bridge inspection vehicle, which is one of boom lift vehicles. Similarly to a known bridge inspection vehicle, the work vehicle <NUM> includes, on the vehicle body <NUM>, the arm mechanism <NUM>, which can move the distal end of the arm to an intended position. The arm mechanism <NUM> may include one or more rotating mechanisms <NUM>, one or more extension mechanisms <NUM>, and one or more derricking mechanisms <NUM>.

As shown in <FIG>, the arm mechanism <NUM> includes, for example, four booms, or a first boom <NUM>, a second boom <NUM>, a third boom <NUM>, and a fourth boom <NUM>, from the base end to the distal end.

The first boom <NUM> includes multiple extendable booms, which are extendable and retractable with the extension mechanism <NUM>. The first boom <NUM> is attached to a rotating platform <NUM> via a derricking shaft <NUM>, which extends parallel to the vehicle body <NUM> of the derricking mechanism <NUM>. The rotating platform <NUM> serves as the rotating mechanism <NUM> that rotates about the vertical axis on the vehicle body <NUM>. The first boom <NUM> can thus rotate and derrick.

The second boom <NUM> includes multiple extendable booms, which are extendable and retractable with the extension mechanism <NUM>. The second boom <NUM> is attached to a leveling arm <NUM>, which serves as the derricking mechanism <NUM> at the distal end of the first boom <NUM>, via a rotating platform <NUM> that allows the third boom <NUM> to rotate.

The third boom <NUM> includes multiple extendable booms, which are extendable and retractable with the extension mechanism <NUM>. The third boom <NUM> is attached via a derricking shaft <NUM>, which serves as the derricking mechanism <NUM> at the distal end of the second boom <NUM>.

The fourth boom <NUM> is coupled to the distal end of the third boom <NUM> via a derricking shaft <NUM> of the derricking mechanism <NUM>, which allows derricking of the fourth boom <NUM>. A work cage mount <NUM>, which can level the work cage <NUM>, is located at the distal end of the fourth boom <NUM>.

The rotating mechanism <NUM>, the extension mechanism <NUM>, and the derricking mechanism <NUM> attached to the first to fourth booms <NUM> to <NUM> together form the arm mechanism <NUM>, which moves the distal end of the fourth boom <NUM> to an intended position.

The rotating mechanism <NUM>, the extension mechanism <NUM>, and the derricking mechanism <NUM> of the arm mechanism <NUM> include a hydraulic driving device, such as a hydraulic cylinder or a hydraulic motor, or an electric driving device. An operator operates the work vehicle <NUM> from an uppermost stop position S of the work cage <NUM> (described later) through an arm operation panel <NUM> for the arm mechanism <NUM>.

Besides the hydraulic driving mechanism, the work vehicle <NUM> has a power source of AC <NUM> to <NUM> V fed from a generator installed on the vehicle body <NUM> to feed power to the arm operation panel <NUM>.

The structure of the arm mechanism <NUM> is a mere example applied to a bridge inspection vehicle. The number of booms or the arrangement of the mechanisms <NUM>, <NUM>, and <NUM> for coupling the booms is not limited to the number or the arrangement described in this embodiment, and may be determined appropriately to enable movement of the distal end of the arm mechanism <NUM> to an intended position.

The suspended platform <NUM> is installed at the distal end of the arm mechanism <NUM>, or specifically on the work cage mount <NUM> at the distal end of the fourth boom <NUM> in the present embodiment.

A vertically extending support post <NUM> is mounted on the work cage mount <NUM>. In the present embodiment, the support post <NUM> serves as a rotating post <NUM>, which rotates about a vertical axis on the work cage mount <NUM>.

The work cage mount <NUM>, on which the support post <NUM> is mounted, may be rotated about the vertical axis by the arm mechanism <NUM>. In this case, the support post <NUM> may be fixed, but can function similarly to the rotating post <NUM>.

The work cage mount <NUM> included in the arm mechanism <NUM> may be rotated with an operation on a work cage operation panel <NUM>, which will be described later.

For example, the rotating mechanism of the rotating post <NUM> is driven by rotating a worm installed on the work cage mount <NUM> and engaged with a worm wheel attached to the rotating post <NUM>. The worm is rotated with a manual handle, or driven by a hydraulic motor or an electric motor.

The suspension frame <NUM> is a wide frame <NUM> (refer to <FIG>) recessed as viewed from above, or a substantially rectangular (refer to <FIG>) frame <NUM>, mounted on the upper end of the rotating post <NUM>. The frame <NUM> or <NUM> has one short side with its center portion protruding toward the rotating post <NUM> for attachment to the rotating post <NUM>. As shown in <FIG>, instead of being a flat frame, the suspension frame <NUM> may be a frame <NUM> combined with sides each having a downward recess in vertical cross section (refer to <FIG> and <FIG>). Instead of having a rectangular cross section, the suspension frame <NUM> may have a cross section of another shape that allows an operator in the work cage <NUM> to perform operations above the suspension frame <NUM>.

The suspension frame <NUM> allows an operator to perform operations in an upper area from inside the frame <NUM>, <NUM>, or <NUM>, unlike in a structure including a single beam.

As shown in <FIG>, the lift mechanisms <NUM>, which raise or lower the work cage <NUM>, are attached to the frame <NUM>, <NUM>, or <NUM> of the suspension frame <NUM>. The lift mechanisms <NUM> include multiple lanyards <NUM>. For example, the multiple lanyards <NUM> include two wire ropes, and are suspended with their upper ends fixed.

As shown in <FIG>, <FIG>, <FIG>, and <FIG>, a twist remover 91a for each lanyard <NUM> is arranged between the suspension frame <NUM> and the lanyard <NUM>. The twist remover 91a allows the lanyard <NUM> to rotate about the center axis to prevent the lanyard <NUM> from being twisted.

The two suspended lanyards <NUM> are wound around the sheaves of endless winders <NUM> installed on the work cage <NUM>. For example, two endless winders <NUM>, which serve as the lift mechanisms <NUM>, are installed on the left and right parts of the work cage <NUM>. The work cage <NUM> has the two lanyards (wire ropes) <NUM> fixed to and suspended from the suspension frame <NUM> and wound around the sheaves of the endless winders <NUM>. The work cage <NUM> is then raised and lowered while changing the winding positions under a frictional force between the lanyards <NUM> and the sheaves of the endless winders <NUM>.

The endless winders <NUM> return to the original positions with manual rotations of the sheaves if the endless winders <NUM> malfunction.

The work cage <NUM> includes a rectangular work floor <NUM>, on which operators stand. The work floor <NUM> is placed substantially perpendicular to the target wall surface during operation. The work floor <NUM> is surrounded by panels <NUM> to allow the operators to perform safe operations. As appropriate, handrails, sheets, or nets for protection against falling objects or debris resulting from the operation are attached to the work cage <NUM>.

As shown in <FIG>, <FIG>, and <FIG>, winding reels <NUM> for winding the two lanyards <NUM> are attached in a self-rotatable manner below the work floor <NUM> of the work cage <NUM>. The winding reels <NUM> with a cage shape rotate in response to a push or pull of the lanyards <NUM> to coil up the lanyards <NUM> for storage.

The endless winders <NUM> are driven by a battery (not shown) mounted on the work cage <NUM>. A battery panel <NUM>, which contains a battery, and the work cage operation panel <NUM> are installed on the work cage <NUM>. The battery mounted on the work cage <NUM> is rechargeable with power from an external power supply through a charging connector on the arm operation panel <NUM> when the work cage <NUM> is at the uppermost stop position S.

Regenerated current can be recovered to the battery from the driving motors of the endless winders <NUM> for energy saving.

The length of the lanyards <NUM> suspended from the suspension frame <NUM> can be adjusted by the endless winders <NUM> to correspond to the range in which the work cage <NUM> is raised or lowered. Thus, the operator can perform operations on the wall surface without limitations while raising or lowering the work cage <NUM> within an intended range.

To perform operations from the work cage <NUM>, the rotational position of the suspension frame <NUM> about a vertical axis is adjusted by the rotation of the rotating post <NUM>. The work cage <NUM> can thus be placed parallel to the target wall surface.

As shown in <FIG>, for example, the suspended platform <NUM> may have the endless winders <NUM> fixed to the work cage mount <NUM> at the distal end of the arm mechanism <NUM> as winches, instead of being installed on the work cage <NUM>.

The lanyards <NUM> may be wired from the fixed endless winders <NUM> to the suspension frame <NUM>, and the suspended lanyards <NUM> such as wire ropes may be connected to the work cage <NUM> to be wound up or unwound to raise or lower the work cage <NUM>. This structure may include a wireless operation panel for operating the winches, such as the endless winders <NUM>, from the work cage <NUM>, and a safe return unit additionally arranged to allow the operator to return to an operation start point when, for example, the winches such as the endless winders <NUM> malfunction.

The endless winders <NUM> installed on the work cage mount <NUM> allow a suspension beam <NUM> including a hook 98a to be arranged, in place of the work cage <NUM>, at an intermediate point between the lanyards <NUM> suspended from the suspension frame <NUM>, and enable a crane operation through the wireless operation panel.

In some embodiments, the endless winders <NUM> installed on the work cage <NUM> may be driven by an external power (power supply from a generator or other devices), in place of a battery, through power cables. This structure includes power cables and reels.

The work vehicle <NUM> including the suspended platform <NUM> includes an interlock mechanism for safe operation. The interlock mechanism operates mechanically and electrically.

During the operation of the suspended platform <NUM>, the interlock mechanism disables the operation of the arm mechanism <NUM>. More specifically, the arm operation panel <NUM> for the arm mechanism <NUM> is installed on the support post <NUM> at the distal end of the arm mechanism <NUM>, or on the rotating post <NUM> in the present embodiment. Thus, the arm operation panel <NUM> is accessible to the operator only when the work cage <NUM> suspended from the suspension frame <NUM> is at the uppermost stop position S. Thus, after the work cage <NUM> is started to move (be lowered), the arm operation panel <NUM> becomes physically inaccessible to the operator to disable the operation of the arm mechanism <NUM>.

For a mechanical lock mechanism, the work vehicle <NUM> includes fastening mechanisms <NUM> between the work cage <NUM> and the suspension frame <NUM> to fix the work cage <NUM> at the uppermost stop position S to the suspension frame <NUM> to prevent the work cage <NUM> from moving (from being lowered). When the upper ends of the fastening mechanisms <NUM> are fixed to the suspension frame <NUM> and hooks 96b at the lower ends of the fastening mechanisms <NUM> are hooked through the openings in the brackets 96c on the work cage <NUM>, the work cage <NUM> is fastened to the suspension frame <NUM>. The fastening mechanisms <NUM> enable simple fastening of the work cage <NUM> by, for example, slightly raising the work cage <NUM> from the uppermost stop position S, hooking the hooks 96b through the brackets 96c on the work cage <NUM>, and then lowering the work cage <NUM> to the uppermost stop position S. The work cage <NUM> is released from the fastened state by being slightly raised and disconnected from the fastening mechanisms <NUM>.

The fastening mechanisms <NUM> fasten the work cage <NUM> to the suspension frame <NUM> to prevent the work cage <NUM> from moving (from being lowered). Thus, the two lanyards <NUM> are left unloaded.

A load detector <NUM> is attached to each lanyard <NUM> for suspending the work cage <NUM>. The load detector <NUM> electrically detects the work cage <NUM> at the uppermost stop position S at which the lanyard <NUM> is unloaded. In other words, for the fastening mechanisms <NUM> to detect the work cage <NUM> fastened to the suspension frame <NUM>, a load cell is installed in the suspension frame <NUM> to serve as a load detector <NUM>. When the lanyard <NUM> is suspended from the suspension frame <NUM>, the load detector <NUM> electrically detects the load on the load cell smaller than a predetermined value.

A mechanical system including a striker attached to the work cage <NUM> and a limit switch installed on the suspension frame <NUM> may be used as the load detector <NUM>. The limit switch may obtain an electric signal indicating that the work cage <NUM> is at the uppermost stop position S. In some embodiments, a proximity sensor may be used to detect the position of the work cage <NUM> to obtain an electric signal indicating that the work cage <NUM> is at the uppermost stop position S.

The load detector <NUM> can electrically detect the work cage <NUM> at the uppermost stop position S at which the lanyard <NUM> is unloaded. This interlocks the work cage <NUM> for operations such as being raised and lowered.

Unless the work cage <NUM> is at the uppermost stop position S, the arm mechanism <NUM> is interlocked to allow no operation.

The work vehicle <NUM> including the suspended platform with the above structure is used to perform operations in the following manner.

The work vehicle <NUM> travels on the road to a work site.

At the work site, an operator prepares to start operations in the vehicle body <NUM>, such as a typical bridge inspection vehicle or a boom lift vehicle. More specifically, the operator performs pre-operation checks, checks the parking conditions, including whether the vehicle is parked on a flat road surface or the state of the parking brake, and manipulates an outrigger.

The operator then enters the work cage <NUM> suspended at the uppermost stop position S at the distal end of the arm mechanism <NUM> and fastened with the fastening mechanisms <NUM>.

Thereafter, the operator in the work cage <NUM> operates the arm operation panel <NUM> attached to the rotating post <NUM> to move the work cage <NUM> to an intended work position (operation start point) with the mechanisms <NUM>, <NUM>, and <NUM> of the arm mechanism <NUM>.

The arm operation panel <NUM> is operable while the work cage <NUM> is interlocked, in which the work cage <NUM> is at the uppermost stop position S and mechanically fastened with the fastening mechanisms <NUM>. This is detected by the load detector <NUM> that electrically detects the unloaded lanyard <NUM> or electrically detects the work cage <NUM> at the uppermost stop position S. This structure ensures the safety of an operation.

In addition, the rotating post <NUM> is rotated by the operation on the work cage operation panel <NUM> to place the work cage <NUM> parallel to the wall surface. This completes the preparations.

To start the operation with the work cage <NUM>, the fastening mechanisms <NUM> release mechanical fastening of the work cage <NUM>. The work cage <NUM> is slightly raised to unhook the hooks 96b of the fastening mechanisms <NUM> from the brackets 96c on the work cage <NUM>.

In response to releasing of the fastened state, the load detector <NUM> detects the loaded lanyard <NUM>, or detects the work cage <NUM> moved from the uppermost stop position S (e.g., the work cage <NUM> is slightly lowered). Thus, the arm operation panel <NUM> is interlocked, disabling operations on the arm mechanism <NUM>. The position of the suspension frame <NUM>, from which the work cage <NUM> is suspended, is thus prevented from being unintentionally changed by the arm mechanism <NUM>.

The operator in the work cage <NUM> can perform operations also above the suspension frame <NUM>. Adjusting the uppermost stop position S of the arm mechanism <NUM> in advance thus enables operations above the suspension frame <NUM>.

The operator operates the work cage operation panel <NUM> to raise or lower the work cage <NUM> to perform operations below the uppermost stop position S. For a curved work surface, the operator operates the work cage operation panel <NUM> to rotate the rotating post <NUM> to change the orientation of the work cage <NUM> to place the work cage <NUM> parallel to the wall surface for performing the operation.

After performing an operation by raising or lowering the distal end of the arm mechanism <NUM> to intended positions, the operator raises the work cage <NUM> to return to the uppermost stop position S to complete the operation in a single up-down range.

After the work cage <NUM> is fastened at the uppermost stop position S, the operator in the work cage <NUM> operates the arm operation panel <NUM> to repeatedly move the distal end of the arm mechanism <NUM> to the subsequent work position while performing operations by raising or lowering the work cage <NUM> in the same manner.

When returned to the uppermost stop position S, the battery mounted on the work cage <NUM> is recharged as appropriate.

After the operation on the entire wall surface is complete by repeatedly moving to another operation start point with the arm mechanism <NUM> and raising and lowering of the work cage <NUM> in combination, the arm mechanism <NUM> is operated to return to the initial position, allowing the work vehicle <NUM> to travel.

To use the work vehicle <NUM> as a crane truck, as shown in <FIG>, the endless winders <NUM> are installed at the distal end of the arm mechanism <NUM>, the suspension beam <NUM> is suspended with two lanyards <NUM>, and a cargo is suspended using the hook 98a on the suspension beam <NUM>. Then, the endless winders <NUM> are operated through the wireless operation panel. Thus, the work vehicle <NUM> can readily be used as a crane truck.

The above embodiment only describes the operation of raising or lowering the work cage suspended from the suspension frame. In some embodiments, the work cage may include a traversing mechanism movable lateral direction to further widen the operating range.

The present disclosure is not limited to the above embodiment, and each component may be modified without departing from the scope of the invention as defined by the claims.

As described in detail in the embodiment, the work vehicle including a suspended platform according to an exemplary embodiment of the present disclosure is the work vehicle <NUM> including the work cage <NUM> to carry an operator, and the arm mechanism <NUM>, which moves its distal end to an intended position by at least one of the rotating mechanism <NUM>, the extension mechanism <NUM>, or the derricking mechanism <NUM> installed on the vehicle body <NUM>. The work vehicle <NUM> includes the suspended platform <NUM>, which includes the support post <NUM>, the suspension frame <NUM>, and the lift mechanisms <NUM>. The support post <NUM> is located at the distal end of the arm mechanism <NUM> and extends vertically. The suspension frame <NUM>, from which the work cage <NUM> is suspended, is mounted on the upper end of the support post <NUM> and located outside the work cage <NUM> to allow an operator to perform an operation above the upper end of the support post <NUM>. The lift mechanisms <NUM> raise or lower the work cage <NUM>, suspended from the suspension frame <NUM> with the lanyards <NUM>, to a work position. The operation panel <NUM> for the arm mechanism <NUM> is operable from the work cage <NUM> at the upper stop position S and inoperable from the work cage <NUM> at a raised or lowered position. Thus, the work vehicle <NUM> can transport the suspended platform <NUM> by traveling a public road. The work cage <NUM> is thus movable to an intended position from above a road by the arm mechanism <NUM>, and the raising or lowering of the work cage <NUM> allows a wide operating range. As in a boom lift vehicle, the work cage <NUM> suspended from the suspension frame <NUM> also enables an operation above the work cage <NUM>, unlike known suspended platform.

The work cage <NUM> of the suspended platform <NUM> is thus movable to an intended position in an operating range without limitations, thus allowing an operation in a wide operating range.

This structure facilitates transportation to a work site or operational preparation or withdrawal at the work site, thus greatly improving the work efficiency as compared with when a work cage is suspended from, for example, a rooftop.

The operation panel <NUM> for the arm mechanism <NUM> is operable from the work cage <NUM> at the uppermost stop position S and inoperable from the work cage <NUM> at a raised or lowered position. Thus, the arm mechanism <NUM> becomes inoperable when the work cage <NUM> is raised or lowered to allow the operator in the work cage <NUM> to perform an intended operation safely. The following paragraphs are part of the disclosure, but are not part of the invention.

A work vehicle including a suspended platform according to an exemplary embodiment of the present disclosure is the work vehicle <NUM> including the work cage <NUM> to carry an operator, and the arm mechanism <NUM>, which moves its distal end to an intended position by at least one of the rotating mechanism <NUM>, the extension mechanism <NUM>, or the derricking mechanism <NUM> installed on the vehicle body <NUM>. The work vehicle <NUM> includes the suspended platform <NUM>, which includes the support post <NUM>, the suspension frame <NUM>, and the lift mechanisms <NUM>. The support post <NUM> is located at the distal end of the arm mechanism <NUM> and extends vertically. The suspension frame <NUM>, from which the work cage <NUM> is suspended, is mounted on the upper end of the support post <NUM> and located outside the work cage <NUM> to allow an operator to perform an operation above the upper end of the support post <NUM>. The lift mechanisms <NUM> raise or lower the work cage <NUM>, suspended from the suspension frame <NUM> with the lanyards <NUM>, to a work position. The work vehicle <NUM> includes the fastening mechanisms <NUM> between the work cage <NUM> and the suspension frame <NUM> to fasten the work cage <NUM> at the uppermost stop position S. The work vehicle <NUM> includes the load detector <NUM> installed in the suspension frame <NUM> to detect a fastened state of the work cage <NUM> at the uppermost stop position S based on the load on the lanyard <NUM>. Thus, the suspended platform <NUM> is transportable through a public road. The work cage <NUM> is thus movable to an intended position from above a road by the arm mechanism <NUM>, and is raised or lowered to allow an operation in a wide operating range. As in a boom lift vehicle, the work cage <NUM> suspended from the suspension frame <NUM> also enables an operation above the work cage <NUM>, unlike known suspended platform.

The work cage <NUM> of the suspended platform <NUM> is movable to an intended position in an operating range without limitations, thus allowing an operation in a wide operating range.

The work vehicle <NUM> includes the fastening mechanisms <NUM> between the work cage <NUM> and the suspension frame <NUM> to fasten the work cage <NUM> at the uppermost stop position S. The work vehicle <NUM> includes the load detector <NUM> installed in the suspension frame <NUM> to detect a fastened state of the work cage <NUM> at the uppermost stop position S based on the load on the lanyard <NUM>. The fastening mechanisms <NUM> can firmly fasten the work cage <NUM> at the uppermost stop position S, and the load detector <NUM> can detect an electric signal indicating the position of the work cage <NUM>. Thus, the suspended platform <NUM> is interlocked depending on the position of the work cage <NUM>, thus allowing safe operations.

A work vehicle including a suspended platform according to an exemplary embodiment of the present disclosure is the work vehicle <NUM> including the work cage <NUM> to carry an operator, and the arm mechanism <NUM>, which moves its distal end to an intended position at least one of the rotating mechanism <NUM>, the extension mechanism <NUM>, or the derricking mechanism <NUM> installed on the vehicle body <NUM>. The work vehicle <NUM> includes the suspended platform <NUM>, which includes the support post <NUM>, the suspension frame <NUM>, and the lift mechanism <NUM>. The support post <NUM> is located at the distal end of the arm mechanism <NUM> and extends vertically. The suspension frame <NUM>, from which the work cage <NUM> is suspended, is mounted on the upper end of the support post <NUM> and located outside the work cage <NUM> to allow an operator to perform an operation above the upper end of the support post <NUM>. The lift mechanism <NUM> raises or lowers the work cage <NUM>, suspended from the suspension frame <NUM> with the lanyards <NUM>, to a work position. The lift mechanism <NUM> in the suspended platform <NUM> is driven by a battery mounted on the work cage <NUM>. The work cage <NUM> is rechargeable at the uppermost stop position S with power from an external power supply. Thus, the suspended platform <NUM> is transportable through a public road. The work cage <NUM> is thus movable to an intended position from above a road by the arm mechanism <NUM>, and the raising or lowering of the work cage <NUM> allows an operation in a wide operating range. As in a boom lift vehicle, the work cage <NUM> suspended from the suspension frame <NUM> also enables an operation above the work cage <NUM>, unlike known suspended platform.

The lift mechanism <NUM> in the suspended platform <NUM> is driven by a battery mounted on the work cage <NUM>. The work cage <NUM> is rechargeable at the uppermost stop position S with power from an external power supply. The lift mechanism <NUM> thus has no power cable between the arm mechanism <NUM> and the work cage <NUM>. This structure thus eliminates operational obstructions or limitations in the operating range, and enables easy recharging of the work cage <NUM> at the uppermost stop position S.

In the work vehicle <NUM> including a suspended platform according to an exemplary embodiment of the present disclosure, the support post <NUM> includes the rotating post <NUM>, which rotates about a vertical axis. Thus, the direction of the suspension frame <NUM> is changeable about the vertical axis by rotating the rotating post <NUM> to adjust the orientation of the work cage <NUM> for performing operations on, for example, wall surfaces. End of paragraphs not being part of the invention but part of the disclosure.

In the work vehicle <NUM> including a suspended platform according to an exemplary embodiment in accordance with claim <NUM> of the present disclosure, the operation panel <NUM> for the arm mechanism <NUM> is operable from the work cage <NUM> at the uppermost stop position S and inoperable from the work cage <NUM> at a raised or lowered position. Thus, an operator in the raised or lowered work cage <NUM> is unable to operate the arm mechanism <NUM>, thus allowing the operator in the work cage <NUM> to perform an intended operation safely. The following paragraphs are part of the disclosure, but are not part of the invention.

The work vehicle <NUM> including a suspended platform according to an exemplary embodiment of the present disclosure includes the fastening mechanisms <NUM> between the work cage <NUM> and the suspension frame <NUM> to fasten the work cage <NUM> at the uppermost stop position S. The work vehicle <NUM> includes the load detector <NUM> installed in the suspension frame <NUM> to detect a fastened state of the work cage <NUM> at the uppermost stop position S based on the load on the lanyard <NUM>. The fastening mechanisms <NUM> can firmly fasten the work cage <NUM> at the uppermost stop position S, and the load detector <NUM> detects an electric signal indicating the position of the work cage <NUM>. Thus, the suspended platform is interlocked depending on the position of the work cage <NUM>, thus allowing an operator to perform safe operations.

In the work vehicle including a suspended platform according to an exemplary embodiment of the present disclosure, the lift mechanisms <NUM> in the suspended platform <NUM> are driven by the battery panel <NUM> mounted on the work cage <NUM>. The work cage <NUM> is rechargeable at the uppermost stop position S with power from an external power supply. The lift mechanisms <NUM> thus have no power cable between the arm mechanism <NUM> and the work cage <NUM>. This structure eliminates operation obstructions or limitations in the operating range, and allows easy recharging at the uppermost stop position S. End of paragraphs not being part of the invention but part of the disclosure.

Claim 1:
A work vehicle (<NUM>) including a suspended platform (<NUM>), the work vehicle (<NUM>) comprising:
a work cage (<NUM>) configured to carry an operator;
an arm mechanism (<NUM>) having a distal end, the distal end being movable to an intended position by at least one of a rotating mechanism (<NUM>), an extension mechanism (<NUM>), or a derricking mechanism (<NUM>) that are installed on a vehicle body (<NUM>); and
the suspended platform (<NUM>) comprising
a support post (<NUM>) located at the distal end of the arm mechanism (<NUM>) and extending vertically,
a suspension frame (<NUM>) from which the work cage (<NUM>) is suspended, the suspension frame ( <NUM>) being mounted on an upper end of the support post (<NUM>), being located outside the work cage (<NUM>) allowing the operator to perform an operation on a portion above the upper end of the support post (<NUM>), and
a lift mechanism (<NUM>) configured to raise or lower the work cage (<NUM>) to a work position, the work cage (<NUM>) being suspended from the suspension frame (<NUM>) with a plurality of lanyards (<NUM>),
characterised in that
the arm mechanism (<NUM>) comprises an operation panel (<NUM>) that is operable from the work cage (<NUM>) at an uppermost stop position (S) and inoperable from the work cage (<NUM>) at a raised or lowered position.