Vehicle for de-icing aircraft

Abstract

A vehicle, suitable for de-icing aircraft, with an articulated boom to which is mounted an operator’s platform 12 with a spray nozzle 10. The operator's platform 12 is mounted on a distal end of the a

Description

FIELD OF THE INVENTION This invention relates to comprising a vehicle for de-icing aircraft of the type provided with an operator's platform mounted at the end of an articulated boom, wherein the boom is adapted to raise the operator’ platform to facilitate the spraying of de-icing and / or anti-icing fluids onto the wings of an aircraft. BACKGROUND OF THE INVENTION In airports with winter conditions for all or part of the year, de-icers are required for the safety of air traffic. For the sake of safe take-offs, aircraft need to have their wing surfaces cleaned from ice and snow formations (de-icing) and, immediately thereafter, the same wings need to be prepared (anti-icing) to protect them against the formation of new layers of snow and ice, to ensure that the aircraft have clean wings during take-off. Specialist vehicles are provided for these operations, typically comprising a truck having a chassis upon which are mounted a driver’s cab and tanks for carrying deicing and anti-icing fluids, pumps, heaters and flow control systems for controlling the flow of selected de-icing and anti-icing fluids to a spray nozzle assembly and upon which chassis is mounted an articulated boom having an operator's platform or basket supported on a distal end of the articulated boom such that the boom can be operated to raise the operator’s platform to allow an operator to spray said deicing and anti-icing fluids, via said spray nozzle assembly, onto the wings of an aircraft. Typically the boom is adapted to move the operator's platform between a lowered transport configuration, wherein the operators platform is located in front of the driver’s cab (to minimise height of the vehicle), and a raised operative positions above the wings of an aircraft to be treated. The operator’s platform is typically pivotally coupled to a distal end of the boom and an actuator, such as a double acting hydraulic ram, is provided, operatively controlled by a suitable control system, to maintain the operator’s platform level during raising and lowering of the boom. A problem with such known systems is that the operator’s platform may tilt uncontrollably when in its transport configuration should fluid pressure within the actuator be lost, resulting in the platform tipping forwarding and striking the ground of other parts of the vehicle. To prevent this, it is known to use transport straps to support the operator’s platform and hold it in a level, upright position, prior to use of the vehicle. However, such transport straps will interfere with operation of the boom if they are not first removed. SUMMARY OF THE INVENTION According to the present invention there is provided a vehicle for de-icing aircraft comprising a wheeled chassis having a driver’s cab at a forward end thereof and at least one tank mounted on the chassis for carrying de-icing and / or anti-icing fluids, a flow control systems for controlling the flow of selected de-icing and anti-icing fluids to a spray nozzle assembly, an articulated boom being mounted on the chassis, an operator's platform being mounted on a distal end of the articulated boom, said spray nozzle assembly being mounted on or adjacent said operator’s platform, whereby the articulated boom can be operated to raise and position the operator’s platform to allow an operator on the platform to spray said de-icing and / or anti-icing fluid onto the wings of an aircraft via the spray nozzle assembly, wherein said articulated boom comprises a main boom section pivotally mounted on the chassis to be moveable between a lowered transport configuration and a raised operative configuration and a distal boom section pivotally coupled to a distal end of the main boom section, said operator’s platform being pivotally coupled to a distal end of the distal boom section via a support beam extending from a distal end of the distal boom section, the orientation of the support beam relative to the distal boom section being controlled by a first hydraulic actuator coupled to a supply of hydraulic fluid via a platform level control system adapted to maintain the operator’s platform level with a horizontal plane during movement of the main and distal sections of the articulated boom, an inner end of the support beam being provided with a surface defining control face including a stepped portion adapted to be selectively engaged by a latch portion of a latch member, said latch member being pivotally mounted on the distal boom section about an axis adjacent and parallel to the pivotal coupling between the support beam and the distal boom section such that the latch member is moveable between a retracted position, wherein a latch portion of the latch member is spaced from said inner end of the support beam to allow the support beam to freely pivot through its full range of motion relative to the distal boom section, and an extend position, wherein the latch portion of the latch member engages said stepped portion of the control face of the support beam to prevent the support beam from pivoting downwardly with respect to the distal boom section beyond a predetermined angle. Preferably, when in a transport configuration, said main boom section extends substantially horizontally and forwardly with respect to the chassis and said distal boom section extends downwardly and substantially perpendicular to said main boom section, with said operator’s platform in front of said driver’s cab, said latch member and said stepped portion of the control face of the support beam being shaped and arranged such that the support beam is maintained perpendicular to the distal section of the boom when the main and distal sections of the boom are in their transport configuration and the latch member is in its extended position, such that the operator’s platform is prevented from tiling downwardly beyond a predetermined transport configuration should fluid pressure within said first hydraulic actuator be lost. Preferably the latch member is biased towards its extended position by means of a biasing means and is urged to its retracted position, against said spring bias, via a second hydraulic actuator, hydraulically coupled to the first hydraulic actuator such that the latch member is moved to its retracted position, allowing free pivotal movement of the support arm with respect to the distal section of the boom, when fluid pressure is supplied to the first hydraulic actuator. The distal section of the boom may comprise a pair of beams arranged parallel to one another and pivotally coupled to and extending between the distal end of the main boom section and a support plate to which the support beam of the operator’s platform is attached, whereby angular orientation between the distal end of the main boom section and the support plate is maintained. The first hydraulic actuator preferably acts between an upper region of the support plate and an inner end of the support beam The main boom section may be mounted on the support structure on the chassis via a turntable arranged to allow the main boom section to slew in a horizontal plane, preferably through 360°. The main boom section may be pivotally mounted on the turntable to be moveable in a vertical plane, under the action of one or more lifting rams, to raise and lower the main boom section, preferably through an angle of approximately 80°, between said transport configuration and raised configuration. The operator’s platform may be mounted on a swivel coupling on a distal end of the support beam to allow the operators platform, and the spray nozzle assembly, to be rotated about a vertical axis perpendicular to the support beam to adjust the direction of spray from the spray nozzle assembly. The operator’s platform may include controls allowing the operator to operate the spray nozzle assembly and the boom. The operator’s platform may include controls for operating the vehicle to allow an operator on the platform to control movement of the vehicle as well as controlling movement of the boom and operation of the spray nozzle assembly. BRIEF DESCRIPTION OF THE DRAWINGS A vehicle for de-icing aircraft according to an embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a side view of a vehicle for de-icing aircraft in accordance with an embodiment of the present invention, with the boom in a transport configuration; Figure 2 is a side view of the vehicle of Figure 1, with the boom in an operative, partially raised configuration; Figure 3 is a side view of the vehicle of Figure 1 with the boom in an operative fully raised configuration; and Figure 4 is a detailed view of a latching mechanism for retaining the basket in a horizontal position when the boom is in its transport configuration. DETAILED DESCRIPTION OF THE DRAWINGS A vehicle for de-icing aircraft according to an embodiment of the present invention is illustrated in the drawings. The vehicle comprises a truck having a wheeled chassis 2 with a driver’s cab 4 and powered by an engine 6 at a forward end thereof. Tanks 8 for carrying de-icing and anti-icing fluids, pumps, heaters and flow control systems for controlling the flow of selected de-icing and anti-icing fluids to a spray nozzle 10 assembly, are mounted on the chassis 2, behind the driver’s cab 4. An articulated boom is mounted on a support structure provided on the chassis 2, preferably adjacent a rear end of the vehicle, more preferably above the rear axle, an operator's platform 12 being mounted on a distal end of the articulated boom, the spray nozzle assembly 10 being mounted on the operator’s platform 12, whereby the boom can be operated to raise and position the operator’s platform 10 to allow an operator on the platform to spray said de-icing and anti-icing fluids onto the wings of an aircraft via the spray nozzle assembly. The operator’s platform 12 may comprise an open topped basket or, as shown in the drawings, a fully enclosed cab. The operator’s platform may include controls allowing the operator to operate the spray nozzle assembly and the boom. The platform may also include controls for operating the vehicle to allow an operator on the platform to control movement of the vehicle as well as controlling movement of the boom and operation of the spray nozzle assembly. As illustrated, the articulated boom preferably comprises a main boom section 14 mounted on the support structure on the chassis via a turntable 15 arranged to allow the main boom section 14 to slew in a horizontal plane, preferably through 360°. The main boom section 14 is pivotally mounted on the turntable 15 to be moveable in a vertical plane, under the action of one or more lifting rams 16, to raise and lower the main boom section 14 between a substantially horizontally and forwardly extending lower position, shown in Figure 1, and an upwardly extending raised position, shown in Figure 3. The main boom section 14 may be vertically pivotable through approximately 80°. A distal boom section 18 is pivotally coupled to a distal end of the main boom section 14 and the operator’s platform 12 is pivotally coupled to a distal end of the distal boom section 18, as described below in more detail. The distal boom section 18 may comprise a pair of beams arranged in parallel to one another and pivotally coupled to and extending between the distal end of the main boom section 14 and a support plate 20 for supporting the operator’s platform, such parallel beam arrangement maintaining angular orientation between the distal end of the main boom section 14 and the support plate 20. When the boom in its transport configuration, the main boom section 14 extends forwardly and horizontally and the distal boom section 18 extends vertically downwardly from the main boom section 14, perpendicular to the main boom section 14, such that the operator’s platform 12 is located in front of the driver’s cab 4, minimising the overall height of the vehicle. The operator’s platform 12, in the form of an enclosed cab in the embodiment shown in the drawings, is mounted on an elongate support beam 22 pivotally attached to and extending from the support plate 20 to be movable in a vertical plane to enable the operator’s platform 12 to be maintained in a horizontal configuration during movement of the main and distal boom sections 14,18. In the embodiment shown, the operator’s platform 12 is mounted on a swivel coupling 24 on a distal end of the support beam 22 to allow the operators platform 12, and the spray nozzle assembly 10, to be swung about a vertical axis perpendicular to the support beam 22 to adjust the direction of spray from the spray nozzle assembly 10. The orientation of the support beam 22 relative to the support plate 20 is controlled by a first hydraulic actuator 26, preferably in the form of a double acting ram, acting between an upper region of the support plate 20 and an inner end of the support beam 22, the first actuator 26 being coupled to a supply of hydraulic fluid from a platform level control system adapted to maintain the operator’s platform 12 level with a horizontal plane during movement of the main and distal sections 14,18 of the articulated boom. An inner end of the support beam 22 adjacent the pivot attachment of the first actuator 26 is provided with a surface defining a control face 28 including a stepped portion 30 adapted to be selectively engaged by a latch portion 32 of a latch member 34, said latch member 34 being pivotally mounted on the support plate 20 about an axis adjacent and parallel to the pivotal coupling between the support beam 22 and the support plate such 20 that the latch member 34 is moveable between a retracted position, wherein a latch portion 32 of the latch member 34 is spaced from said control face 28 of the support beam 22 to allow the support beam 22 to freely pivot through its full range of motion relative to the support plate 20, and an extended position, wherein the latch portion 32 of the latch member 34 engages said stepped portion 30 of the control face 28 of the support beam 22 to prevent the support beam 22 from pivoting downwardly with respect to the support plate 20 beyond a predetermined angle. The latch member 34 and stepped portion 30 of the control face 28 of the support beam 22 are preferably shaped and arranged such that the support beam 22 is maintained perpendicular to the distal section 18 of the boom when the main and distal sections 14,18 of the boom are in their transport configuration and the latch member 34 is in its extended position, such that the operator’s platform 12 is prevented from tiling downwardly when in its transport configuration should fluid pressure within the first actuator 26 be lost. The latch member 34 is preferably biased towards its extended position by means of a biasing means, such as a spring, and is urged to its retracted position, against said spring bias, via a second hydraulic actuator 36, hydraulically coupled to the first actuator 26 such that the latch member 34 is moved to its retracted position, allowing free pivotal movement of the support arm 22 with respect to the support plate 20, when fluid pressure is supplied to the first actuator 26 (and hence also to the second actuator 36). As such, when the boom is in its transport configuration and fluid pressure is lost from the first actuator 26, the latch member 34 automatically extends to its extended position, under the action of the biasing means, causing the latch portion 32 of the latch member 34 to engage the stepped portion 30 of the control face 28 of the support beam 22,thereby preventing the support beam 22, and the operator’s platform 12 attached thereto, from tipping forwardly and downwardly, thereby maintaining the operator’s platform 12 in a horizontal configuration at the front of the driver’s cab 4 of the vehicle and avoiding the need for transport straps to be applied. However, as soon as hydraulic pressure is applied to the first actuator 26 when the vehicle is in use, the latch member 34 is automatically moved to its retracted position by the action of the second actuator 36, permitting movement of the support arm 22 with respect to the support plate 20 through its full range of motion, thereby allowing correct operation of the platform level control system. While the present invention has been described in relation to a vehicle for de-icing aircraft, it is envisaged that a vehicle in accordance with the present invention may serve other uses, for example for washing aircraft, wherein a washing fluid may be sprayed from the spray nozzle assembly of the operator’s platform. The invention is not limited to the embodiment described herein but can be amended or modified without departing from the scope of the present invention.

Claims

1. A vehicle for de-icing aircraft comprising a wheeled chassis having a driver’s cab at a forward end thereof and at least one tank mounted on the chassis for carrying de-icing and / or anti-icing fluids, a flow control systems for controlling the flow of selected de-icing and anti-icing fluids to a spray nozzle assembly, an articulated boom being mounted on the chassis, an operator's platform being mounted on a distal end of the articulated boom, said spray nozzle assembly being mounted on or adjacent said operator’s platform, whereby the articulated boom can be operated to raise and position the operator’s platform to allow an operator on the platform to spray said de-icing and / or anti-icing fluid onto the wings of an aircraft via the spray nozzle assembly, wherein said articulated boom comprises a main boom section pivotally mounted on the chassis to be moveable between a lowered transport configuration and a raised operative configuration and a distal boom section pivotally coupled to a distal end of the main boom section, said operator’s platform being pivotally coupled to a distal end of the distal boom section via a support beam extending from a distal end of the distal boom section, the orientation of the support beam relative to the distal boom section being controlled by a first hydraulic actuator coupled to a supply of hydraulic fluid via a platform level control system adapted to maintain the operator’s platform level with a horizontal plane during movement of the main and distal sections of the articulated boom, an inner end of the support beam being provided with a surface defining control face including a stepped portion adapted to be selectively engaged by a latch portion of a latch member, said latch member being pivotally mounted on the distal boom section, about an axis adjacent and parallel to the pivotal coupling between the support beam and the distal boom section, such that the latch member is moveable between a retracted position, wherein a latch portion of the latch member is spaced from said control face of the support beam, to allow the support beam to freely pivot through its full range of motion relative to the distal boom section, and an extend position, wherein the latch portion of the latch member engages said stepped portion of the control face of the support beam to thereby prevent the support beam from pivoting downwardly with respect to the distal boom section beyond a predetermined angle.

2. A vehicle as claimed in claim 1, wherein, when in a transport configuration said main boom section extends substantially horizontally and forwardly with respect to the chassis and said distal boom section extends downwardly and substantially perpendicular to said main boom section, with said operator’s platform in front of said driver’s cab, said latch member and said stepped portion of the control face of the support beam being shaped and arranged such that the support beam is maintained perpendicular to the distal section of the boom when the main and distal sections of the boom are in their transport configuration and the latch member is in its extended position, such that the operator’s platform is prevented from tiling downwardly beyond a predetermined transport configuration should fluid pressure within said first hydraulic actuator be lost.

3. A vehicle as claimed in claim 1 or claim 2, wherein said latch member is biased towards its extended position by means of a biasing means and is urged to its retracted position, against said biasing means, via a second hydraulic actuator, hydraulically coupled to the first hydraulic actuator such that the latch member is moved to its retracted position, allowing free pivotal movement of the support arm with respect to the distal section of the boom, when fluid pressure is supplied to the first hydraulic actuator.

4. A vehicle as claimed in any previous claim, wherein said distal section of the boom comprises a pair of beams arranged parallel to one another and pivotally coupled to and extending between the distal end of the main boom section and a support plate to which the support beam of the operator’s platform is attached, whereby angular orientation between the distal end of the main boom section and the support plate is maintained.

5. A vehicle as claimed in claim 4, wherein said first hydraulic actuator acts between an upper region of the support plate and an inner end of the support beam, inward of the pivotal coupling between the support beam and the support plate.

6. A vehicle as claimed in any preceding claim, wherein said main boom section is mounted on the support structure on the chassis via a turntable arranged to allow the main boom section to slew in a horizontal plane.

7. A vehicle as claimed in claim 6, wherein said main boom section is pivotally mounted on the turntable to be moveable in a vertical plane, under the action of one or more lifting rams, to raise and lower the main boom section, preferably through an angle of approximately 80°, between said transport configuration and raised configuration.

8. A vehicle as claimed in any preceding claim, wherein said operator’s platform is mounted on a swivel coupling on a distal end of the support beam to allow the operators platform, and the spray nozzle assembly, to be rotated about a vertical axis perpendicular to the support beam to adjust the direction of spray from the spray nozzle assembly.

9. A vehicle as claimed in any preceding claim, wherein said operator’s platform includes controls allowing the operator to operate the spray nozzle assembly and the boom.

10. A vehicle as claimed in claim 9, wherein said operator’s platform includes controls for operating the vehicle to allow an operator on the platform to control movement of the vehicle as well as controlling movement of the boom and operation of the spray nozzle assembly.

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