AU680335B2 - Wheeled vehicle for ground transport of aircraft - Google Patents

Description

1

AUSTRALIA

Patents Act 1990 Kalmar Motor AB

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT Invention Title: "Wheeled vehicle for ground transport of aircraft" S. 55

S

The following statement is a full description of this invention including the best method of performing it known to us:-

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WHEELED VEHICLE FOR GROUND TRANSPORT OF AIRCRAFT The present invention relates to a wheeled vehicle for transporting aircraft along the ground, comprising an engagement and hoisting unit supported by the chassis of the vehicle and arranged to be raised from a starting position in order, when in free surface contact with the nose heels of the aircraft on both sides of the contact point between nose wheels and ground, to be brought into releasable engagement with the nose wheels so that they are lifted simultaneously from the ground.

It is known to use tow-vehicles with gripping devices operating with parallel telescopic arms provided with I folding cross-pieces and engaging the nose wheels of the •aircraft from behind and hydraulically pull the tow- -vehicle towards the nose gear. The nose-gear wheels are thus drawn either towards a scoop-like device as suggested in German patent No. 3 318 077, or the nose wheels are drawn up on a sloping plane before being S" locked by the gripping arms so that they can be lifted.

o The object of the invention is to provide an improved device in a vehicle for transporting aircraft on the i ground, which enables the vehicle to be simply and quickly coupled to the aircraft without the latter being dislodged and without any parts having to be locked to the nose gear or its wheels prior to lifting and transport.

The vehicle according to the present invention is characterized in that said engagement and hoistirig unit comprises two support side members spaced apart and defining a space between them to receive the nose wheels without their coming into contact with the opposite surfaces of said support side members; a stationary inner counter member with an inner support surface, arranged II close to ground level for engagement with lower portions of the nose wheels during said hoistiAg; a movable outer counter member disposed close to ground level for engagement with lower portions of the nose wheels located on the opposite side of said contact point between the nose wheels and ground in relation to said lower portions for engagement of the stationary inner counter member; a lifting means arranged to lift the engagement and hoisting unit and nose wheels from the ground upon engagement of said counter members with the nose wheels; said outer counter member being in the form of a gate pivotably journalled about a vertical axis on one of the support side members and arranged to be moved between an S"open position in which the nose wheels can be received :i 15 within the space of said engagement and hoisting unit without contact therewith, and a closed position in which the free end of said gate is located beside and secured to the other support side member to enclose the nose wheels in said space without necessarily contacting them; said outer counter member comprising a horizontal plate with an inner, downwardly sloping support surface; said.

inner counter member being arranged by moving the vehicle in relation to the nose wheels to be brought into a starting position close to the nose wheels without necessarily touching them, in front of their point of contact with the ground; said inner support surface of said horizontal plate being arranged, when the gate is in closed position, to assume a starting position close to the wheels without necessarily touching them, behind their point of contact with the ground; and said engagement and hoisting unit being connected to the chassis by a pluralitcy of parallel arms with spherical bushings on each end, enabling the engagement and hoisting unit to be lifted parallel to the ground, and also swivelled 50-150 in each direction around an axis parallel to the longitudinal axis of the vehicle.

I- 'i-e~-llv 3 Besides the device according to the present invention being considerably simpler than said known tow-vehicles, it also has the advantage over them that it avoids the technically complicated problem of having two different hydraulically operated cylinders for the telescopic arms to move exactly uniformly. Furthermore, tow-vehicles with telescopic gripping arms must be manoeuvred straight in towards the centre of the nose gear while the arms are being retracted. If the nose gear is inclined it may be, impossible to subsequently perform the locking and raising operations the torsion link protruding between .:and behind the wheels on many types of aircraft is, for instance, a hinder. In the device according to the invention the prospective lifting position can be checked before the gripping member, i.e. the gate, is operated, thereby reducing the risk of damage. The use of the known tow-vehicles with telescopic gripping arms also implies that, while the gripping arms are being retracted, unless complicated precautions are taken, the nose gear is subjected to forces that may dislodge the aircraft if the brake is not engaged. For reasons of safety, therefore, the pilot or a mechanic should assist during the pulling in stage (engage the brakes on the aircraft), thus S"entailing intervention in the current routines. In the case of aircraft parked at airline gates any movement inwards/forwards is more dangerous than a movement outwards/backwards. The use of tow-vehicles with telescopic gripping arms that utilize a rear scoop device on each gripping arm, similar to the construction described and shown in German patent No. 3 318 077, is limited to aircraft without deflectors devices similar to mudguards, placed a few centimetres off the ground behind the wheels. The height of the scoop is limited to maximally about 4 cm but should preferably be less since it cannot otherwise be brought into contact with the tyres. This greatly complicates the design of the rear end pieces on the gripping arms, or implies that the towi i I -4 1 I -vehicle cannot be used on any medium-sized Douglas aircraft (DC9/MD8O), these constituting a considerable proportion of the aircraft now in use. For this reason the lower part of the gate in the device according to the present invention is in the form of a horizontal plate disposed close to ground level. Besides the complicated design of the gripping arm structure, the embodiment with telescopic gripping armc combined with inclined plane also requires the cross pieces of the gripping arms to be able to rotate during the phase of gripping when the nose wheels are pulled over, i.e. while rolling, onto the inclined plane. The nose gear will also be lifted quite considerably even during the gripping phase. If the aircraft is parked at a gate with the passenger bridge in S 15 contact with the area around the door of the aircraft, such a gripping operation cannot be performed for reasons of safety. The operation cannot therefore be commenced until the gate has been removed from the aircraft. The extra time incurred entails a deterioration of procedures 20 both in comparison with the traditional procedure using a 0o tractor tow-bar and with the procedure performed by the vehicle according to the present invention. There are several types of aircraft in which the nose-gear strut is *:oq1 not vertical. The lifting device must then be able to oscillate about a substantially horizontal axis in longitudinal direction of the tow-vehicle. The gripping i arms, bulky even when collapsed, as well as the separate depressors required to prevent the nose gear from jumping out of position, must also be brought to execute the oscillatory movement. This can be achieved in a considerably simpler manner in the design according to the present invention in which gripping arms, cross- -pieces and depressors are replaced by a simple gate.

The invention will be described in more detail in the following with reference to the accompanying drawings.

1 I i LII gure 1 is a view from above of a vehicle with an engagement and hoisting unit according to an embodiment of the invention.

Figure 2 is a side view of the vehicle according to Figure 1.

Figures 3 a-c are side views of an engagement and hoisting unit according to an embodiment substantially corresponding to that in the vehicle according to Figure 1.

Figure 4 is a view from above of the engagement and hoisting unit shown in Figures 3 a-c, in closed position.

Figure 5 is a view from above of the engagement and hoisting unit shown in Figures 3 a-c and 4, in semiclosed position.

Figures 1 and 2 show schematically a vehicle for transporting aircraft (not shown) relatively short distances along the ground. The vehicle has a chassis 1 with a motor 2 at one end and being provided at the other end with two longitudinal, horizontal beams 3, 4 disposed a predetermined distance from each other so that a sufficiently wide space 5 is formed between them, said space being open upwardly, downwardly and backwardly. The space 5 is thus open and accessible so that during a docking procedure the space 5 can receive the nose wheels of the nose gear of the aircraft when the vehicle is moved on its front and rear pairs of wheels 6, 7 in the longitudinal direction of the aircraft. The vehicle is provided with a cabin for the driver and operating equipment. The operating equipment may include wire- -guiding means enabling the driver to walk beside or behind the vehicle in order to provide a better overall view of the docking procedure and subsequent towing.

-I I~ According to the present invention the vehicle is equipped with a special device to bring it into freely supporting engagement with the nose wheels 9 as the only point of engagement, the rest of the vehicle thus having no contact or engagement with the nose gear. The device shown comprises an engagement and hoisting unit 10 which is located in the space 5 and is pivotably journalled to the chassis 1, by means of a lifting yoke 16, pivot axle 17, and four parallel arms 18. The parallel arms 18 have spherical bushings on their ends and enable the engagement and hoisting unit 10 to be lifted parallel to the ground, and also swivelled 5°-15° in each direction arourr- an axis parallel to the longitudinal axis of the vehicle. The engagement and hoisting unit 10 comprises 15 two spaced support side members 11, 12 disposed on the inner sides of the beams 3, 4, and an inner counter member 13 rigidly or adjustably connected to the support 0 side members 11, 12 and having an inner, concave support surface with a contour substantially corresponding to the radius of the nose wheels. The inner counter member 13 may be adjustable to different sizes of nose wheels 9.

Thus, it may be supported by hydraulic cylinders which adjust the counter member in a position desired. The engagement and hoisting unit 10 is also provided with a movable outer counter member 14 in the form a a gate arranged to close the space 15 between the support side members 11, 12. The gate 14 is pivotably suspended on a vertical pole 28 on one support side member 12 enabling it to be swung about a vertical axis from an open position when it extends along one chassis beam, to a closed position when the free end of the gate 14 is located in the vicinity of the other support side member 11 and can be locked in place by means of a suitable locking device 19, e.g. a hydraulic cylinder that can pull the gate 14 into a groove in the support side member 11. The swinging-movement of the gate 14 is achieved with the aid of a pneumatic or hydraulic cylinder 20, the I i i -ur i I piston rod 21 thereof being pivotably conne.cted to a link arm 22 which is in turn rigidly connected, i.e. fixed to the gate 14. The gate is provided with two upper supports 23, suitably in the form of horizontal bars. The bars 23 are arranged to be brought into abutment with upper parts of the nose wheels 9. Another bar 24 swings around pivots on the inside of the support side members 11, 12 and is arranged to be hydraulically brought in abutment with the upper parts of the nose wheels 9 of the aircraft. The gate 14 comprises a horizontal plate 33 having a support surface 26 arranged opposite the lower part of the inner concave support surface of the inner counter member 13.

When the vehicle has been driven into position in front of the nose wheels 9, the driver opens the gate 14 and drives the vehicle further forward so that the beams 3, 4 straddle the nose wheels 9, the wheels thus being accommodated in the space 5. The vehicle is moved so far in a first stage that the nose wheels 9 are located between the support side members 11, 12 and at a distance of about 300-100 mm from the concave support surface of the stationary inner counter member 13. There is sufficient space between the support side members 11, 12 for the centre line of the nose wheels 9 to be displaced approximately ±70 from the'centre line of the engagement and hoisting unit 10. In a second stage the vehicle is then moved slowly so that the distance between the concave support surface of the inner counter member 13 and the nose wheels 9 is reduced to approximately 3 mm.

This distance is not critical but it is neither necessary nor desirable for the nose wheels 9 to come into contact with said support surface. The gate 14 is then closed with the aid of the cylinder 20 and secured in closed position by means of the locking device 19. Then the bars 23 and 24 are brought into contact with the nose wheels 9. The engagement and hoisting unit 10 then hoists the nose wheels 9 with the aid of hydraulic cylinders 27 ~arlC 8 acting upon the yoke 16, and connected to the chassis 1, whereupon the inner counter member 13 and plate 33 are brought into free-supporting engagement with facing lower portions 29, 30 of the nose-wheel treads 31 located on both sides of the point of contact 32 with the ground.

The nose wheels 9 will thus be raised about 15-50 nmm off the ground in the case of an aircraft with vertical nose gear and about 100 mm in the case of an aircraft with inclined nose gear. The aircraft is now ready for towing to the desired position where the tow-vehicle's engagement and hoisting unit 10 is released from the nose wheels 9 by performing the procedure described above in 'ie reverse order.

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Claims (2)

1. 2. A vehicle as recited in claim 1, characterized in that said gate is provided with horizontal upper 0I supports arranged to be brought into engagement with upper portions of the nose'wheels in the closed position of said gate.
2. 3. A vehicle as recited in claim 1, characterized in that said engagement and hoisting unit is arranged to be lifted with the aid of said lifting gear so that the nose wheels are raised to a transport position about 15-100 mm above ground level. DATED THIC 17 DAY OF MARCH 1995 KALMAR MOTOR AB Patent Attorneys for the Applicant:- F.B.RICE CO. -g IPII qi a II I ABSTRACT A wheeled vehicle for transporting aircraft along the ground comprises, according to the invention, an engagement and hoisting unit (10) supported by the chassis of the vehicle, said unit being arranged during movement of the vehicle in relation to the nose wheels to be brought into a starting position close to but not touching the nose wheels of the aircraft, in front of and behind the contact point (32) between nose wheels and ground, and is also arranged to be raised from said starting position and, by means of free surface contact with the treads (31) of the nose wheels on both s-dzs of said contact point (32) with the ground, to 15 be brought into releasable engagement with the nose wheels thereby simultaneously lifting them off the ground. Furthermore, said unit (10) is connected to the chassis by a plurality of parallel arms (18) enabling the unit (10) to be lifted parallel to the ground and swivelled around an axis parallel to the longitudinal axis of the vehicle. i