WO2018054669A1

WO2018054669A1 - Aircraft tow bar

Info

Publication number: WO2018054669A1
Application number: PCT/EP2017/072089
Authority: WO
Inventors: Ulrich Ockenfuss; Lothar Mikowski
Original assignee: Hydro Systems Kg
Priority date: 2016-09-21
Filing date: 2017-09-04
Publication date: 2018-03-29
Also published as: DE102016218054A1; DE102016218054B4

Abstract

The invention relates to tow bars (1) for aircraft. The aircraft tow bar (1) according to the invention comprises a tow head (2) having a first tow head part (3) fixed to one end of the tow bar (1) and a second tow head part (6) connected to the first tow head part (3) by means of at least one shear bolt (7), with a connection device (8) for detachable connection to an aircaft. At least one collecting basket (40) is arranged on the first tow head part (10), said collecting basket surrounding at least one end of a shear bolt (30) protruding out of the first tow head part (10), in order to catch fragments created on this end during the shearing of the at least one shear bolt (30).

Description

Tow bar for aircraft

The invention relates to tow bars for aircraft.

In the prior art it is known to move aircraft on the ground by means of towing vehicles. Thus, for example, commercial aircraft are regularly towed by a parking position or a gate position of a

Airplane terminals pushed backwards on the tarmac, from where the aircraft can then independently roll forward to the runway. In a variant, the corresponding towing operations Zvi ^¬ rule the towing vehicle and the front landing gear of the aircraft is attached to a tow bar which transmits the only connection Zvi ^¬ rule the towing vehicle and the aircraft, all forces between the two. In order to prevent overloading being transmitted via the tow bar, which leads to damage to the nose gear of the aircraft, the

Tow bar regularly shear bolts, which are secured by means of nuts or cotter pins against accidental slipping out under load and break in case of overload. If an overload occurs, the force flow between the towing vehicle and the aircraft is interrupted before the overload can cause damage to the aircraft.

When breaking the shear bolts of a tow bar, there is a danger that sheared off segments of the shear bolts will fall and fall to the ground, where they are extremely dangerous for air traffic would mean dangerous foreign bodies. It is therefore known to secure the shear bolts of a tow bar at its two ends in each case with a fishing line in order to prevent a possibly falling off of the sheared ends when breaking the shear bolt.

Even if the falling off of the ends of the shear bolt can be effectively prevented during its breaking by means of corresponding catch cords, in this way only the parts of the shear bolt which are directly connected with the catch cords can actually be secured. In particular, if the shear pin does not clean at the designated places or where the shear pins are often notched, shearing but it fragments occur that are not connected to the fishing lines, these fragments can fall freely on the ground and thus dangerous Foreign bodies for air traffic.

It is an object of the present invention to provide a tow bar for aircraft, in which this risk is avoided or at least reduced.

This problem is solved by a tow bar according to the main claim. Advantageous developments are the subject of the dependent claims.

Accordingly, the invention relates to a tow bar of air ^¬ vehicles comprising a towing head with a disposed at one end of the tow bar first valve head part and, with the first valve head part over at least a Scherbol ^¬ zen associated second valve head part with a connection ^¬ device for releasable connection to an aircraft in which at the first valve head portion, a collecting basket is angeord ^¬ net least, encloses at least one projecting from the first valve head portion end of a shear pin to collect in shear of unloading at least one shear pin at that end standing fragments.

In the drag bar according to the invention, a two-part tow head is provided, the two parts are so connected via wenigs ^¬ least a shear bolt which shears when a predefined overload occurs, which then no

Forces can be transmitted between the two parts of the drag head more, so that a possibly occurring in the tow bar overload can be kept away from the connectable to the drag head over the Ver ^¬ bonder plane.

Here, at least one end of at least one shear pin of the ^¬ art surrounded by a catcher that a sheared at that end of the shear pin segment but also there all resulting fragments are reliably collected so that they do not fall down to the ground. Compared to the prior art so not only individual segments of a shear bolt are secured against falling. This reduces the risk of dangerous foreign objects falling onto a runway or runway if the drag bar is overloaded and the shear pin or shears shear off as a result.

The at least one shear bolt is preferably guided at least partially in a shear bushing in the first drag head part. Depending on the configuration of the two parts of the drag head ^¬ the at least one shear pin may also be in two spaced-apart regions in the shear connector in the first Be guided, the shear pin is guided in the intermediate region by the second Schleppkopfteil. The shear pin can also be guided in the second tow head part in a shear connector. A shearing bush can be fastened in particular by press-fitting in a tow-head part.

The at least one shear bush or at least one of the

Shear connectors on the first valve head portion preferably comprise egg NEN on protruding from the first valve head part union Fort ^¬ rate at which a pot can be detachably fastened at least.

Alternatively - for example, in cases where no shearing bushing is provided - it is also possible for an adapter element to be provided on the outside of the first towing head part, through which at least one shear bolt extends and to which the at least one collecting basket can be detachably fastened. The Adap ^¬ terelement can be attached, for example. With rivets or bolts on the first valve head portion. But it is also possible that the adapter element is formed integrally with the outside of the first tow-head part forming at the point in question component. It is preferred if the collar extension or the Adapterele ^¬ ment are annular and further preferably have a thread or a part of a bayonet closure, via which or the catcher can be releasably connected to the first towing head part. As a result, a simple attachment and release of the catcher is possible. In the case of a bayonet lock, it is particularly preferred if the collar extension or the adapter element at least one, preferably two backup pin ^¬ have the Baj onettverschluss. Is a thread provided on the collar extension or adapter element, this is preferably an external thread.

The collecting basket is preferably designed to be suitable for direct connection to the collar extension or the adapter ring. In the case of a screw or a bayonet connection, the catcher preferably has a thread or a part of a bayonet closure, wherein the catcher preferably has at least one, preferably two guide slots for the Baj onettverschluss in the latter case. If a thread on the catch ^¬ basket provided, it is preferably a Innenge ^¬ winch. The collector can cooperate directly with a corresponding counterpart on a collar extension or adapter element of the first valve head portion to the detachable connection of pot and the first drag head part to sheep ^¬ fen.

Alternatively, it is also possible that for fastening the at least one collecting basket, a catching ring enclosing the catching ring is provided, which is adapted for releasable connection with the collar extension or the adapter ring. For this purpose, the coupling ring preferably has a thread or egg ^¬ nen part of a bayonet lock, preferably at least ei ^¬ nen or two guide slots of a bayonet ^lock on. In this case, the catcher does not interact directly with the thread or the part of a bayonet lock on the first shaving head, but is secured via the coupling ring on the collar extension or the adapter ring. By not having to design the catcher for immediate connection, it can usually be made simpler and cheaper. The use of materials for the grass catcher, which Do not allow connection elements, so possible. There is provided a thread on the coupling ring, this is preferably a nengewinde In ^¬. In the case of using a coupling ring is preferred if a spring element is provided between the at least one collecting basket and coupling ring. As a result, the catcher can be well fixed relative to the first tow head. In the case of a bayonet closure for the coupling ring, the spring element can also serve to secure the bayonet closure. The spring element is preferably annular, further preferred ^¬ as an elastomeric ring or a wave spring, preferably made of metal. The retrieval basket is preferably at least partially looking through ^¬ permeable. This makes it possible to check with mounted catcher, whether a segment or fragments of the respective Scherbol ^¬ Zen is in the catcher, so the shear pin is sheared off due to overloading. If this is the case, the

Scherbolzen be replaced, what usually first the catcher must be removed. Particularly when vorbe ^¬ signed attaching the safety cage via threaded or bayonet closure but this is quickly and easily possible. The collector may be made of plastic blickdurchlässigem, of a flexible web or of a rigid wire mesh, wherein the mesh of the network of the wire mesh or preferably greater equal to 1.5 mm in front ^¬. A corresponding Ma ^¬ mesh size is sufficiently large to ensure the views permeability, while small enough to catch even smaller fragments of the shear pin to Kings ^¬ nen. In the case of a flexible network, this one can be fixed Have circlip, which serves the attachment of the catcher.

It is preferred if more than one shear bolt is provided for connecting the two drag head parts, wherein at least one catching basket is preferably provided for each shear bolt. If the shear pin or pins are oriented in the vertical direction when the tow bar is used correctly, the catching basket or baskets are preferably arranged at the bottom end of the individual shear bolts. In another or variable orientation of the shear bolt with proper use of the tow bar may also be provided to provide a catcher at both ends of a shear bolt.

The invention will now be described by way of example with reference to an advantageous embodiment with reference to the accompanying drawings. FIG. 1 shows a partial view of an advantageous embodiment of a tow bar according to the invention;

FIG. 2 shows a detailed view of the tow bar from FIG. 1 in FIG

Exploded view;

FIG. 3 shows a sectional view through the detail illustration according to FIG

Figure 2; and

Figure 4: an alternative embodiment of the tow bar according to

FIGS. 1 to 3.

In Figure 1 is shown one end of an inventive tow bar 1, to which the drag head is 2 buildin ^¬ Untitled. In the part not shown, the tow bar is the first designed according to the prior art and includes insbeson ^¬ particular at its other end, not shown, a normalized drawbar eye for connection to a towing vehicle. The tow head 2 is fastened to the tow bar 1 with a first tow head part 10. This includes the first

Towing head part 10 has a flange 11 and two horizontal plates 12, 13 attached thereto. Between the plates 12, 13, a second tow-head part 20 is inserted and connected to the first tow-head part 10 via a plurality of shear bolts 30. The second tow head part 20 has a locking claw as a connecting device 21, with which the tow bar 1 can be releasably connected to an aircraft, in particular the nose gear of an aircraft.

FIG. 2 shows in detail the region of the towing head 2 with one of the shear bolts 30, the catching basket 40 described below being shown away from the tow head 2 for a better overview. Figure 3 shows a sectional view through the figure 3, wherein the catcher 40 is shown, however, in the mounted state.

The shear pin 30 is ge by mutually aligned through holes 14, 15, 22 in the two Schleppkopfteilen 10, 20 and the plates 12, 13 of the first Schleppkopfteils 10 leads ^¬ , wherein the respective through holes 14, 15, 22 each with pressed shear sockets 16, 17, 23 are equipped. The shear pin 30 has a widened against the shaft 31 shear bolt head 32. With the shear bolt head 32, the shear bolt 30 bears against the first drag head part 10 or the shear bushing 17, thus preventing the shear bolt 30 from slipping through. In order to avoid sliding out of the shear pin 30 in the other Rich ^¬ tion - eg. When loaded during use - to avoid the shear pin 30 is secured at its other end with a threaded nut 34, which also on the first

Towing head part 10, namely the shear sleeve 16 is present. The securing via the threaded nut 34 offers the advantage that the notches 35 provided on the shear bolt 30, which define predetermined breaking points, are secured to the respective ones

Interfaces between the first and the second Schleppkopf- part 10, 20 are arranged. If there is an overload, the shear bolt 30 breaks at the notches 35, so that subsequently the second tow head part 20 can slide between the two plates 12, 13 of the first tow head part 10. In this case, no more power is transmitted via the tow head 2, which in particular the overload is not transmitted to the aircraft connected to the tow bar 1 and possibly cause damage there.

If there is a fracture of the shear pin 30 due to an overload, falls regularly segments or fragments of the shear pin 30 due to the gravity from the imple ^¬ approximately openings 14, 15, 22. In the illustrated embodiment, upon proper use of the tow bar 1, in particular in the segment of the shear pin 30 on which the threaded nut 34 is arranged, any fragments arising up to the lower notch 35 as well as fractures at the lower notch 35 may fall out of the through-opening 14 downwards. In order to prevent that the questionable segment of the shear bolt 30 or fragments fall to the ground and possibly represent a danger to aviation there, a catcher 40 is provided, which in the area of the threaded nut 34 via the first tow head 10 protruding end of the

Scherbolzens 30 encloses and so can catch the resulting fracture of the Scherbol ^¬ zen 30 fragments. The catcher 40 is made of a stainless steel wire mesh with a mesh size of 1.5 mm and is secured with a union ^¬ ring 41 on the first tow head 10. For this purpose, the shear bush 16 at the end of the shear bolt 30 in question an annular collar extension 18 which is provided on the outside with two opposite securing pins 19, which serve as part of a bayonet closure.

The coupling ring 41 has two, for a Baj onettverschluss suitably shaped guide slots 42, in which the securing pins 19 of the collar extension 18 can be performed. To secure the bayonet lock and to fix the catcher 40, a wave spring 43 made of metal is provided between the coupling ring 41 and the catcher 40. Due to the mesh size of the retrieval basket 40 that is looking ^¬ permeable, so the retrieval basket 40 can be checked from the towing head 2 without removing, if fragments of the shear pin 30 located in the catcher 40th It is possible to quickly check whether the shear pin 30 is broken due to an overload or not. If this is the case and the shear pin must be replaced 30, can the catcher 40 due to the bayonet lock quickly and remove a ^¬ times. The replacement of the shear pin 30 can then be done as usual in the art, and after the replacement of the catcher 40 can be easily re-assembled.

FIG. 4 shows a variant embodiment of the tow bar 1 according to the invention according to FIGS. 1 to 3, in which either no shear bushing 16 is provided or at least does not have a collar extension 18.

In this case, an annular adapter member 50 is provided for hen, which as at the one plate 12 mounted to the first valve head part 10 and insbeson ^¬ wider and, for example, is fastened by rivets 51, that the shear pin 30 extends through the adapter ring 50 therethrough. The adapter element 50 has on its outer side two opposing securing pins 19 for a Baj onettverschluss, which can interact with the Führungsschlit ^¬ zen 42 of the coupling ring 41 in the Figures 1 to 3 Darge ^¬ presented manner.

Claims

claims

Tow bar (1) for aircraft comprising a towing ^¬ head (2) having a first at one end of the tow bar (1) arranged first valve head part (10) and a with the first valve head portion (10) second drag head portion connected via at least one shear pin (30) (20) with a connection device (21) for detachable connection to an aircraft,

characterized in that

at the first valve head part (10) at least one collecting basket (40) is arranged, which surrounds at least one of the first valve head part (10) protruding end of a Scherbol ^¬ zen (30) on shearing of the at least one shear pin (30) at this end to catch any resulting fragments.

Tow bar according to claim 1,

characterized in that

the at least one shear pin (30) in the first

Drag head portion (10) is at least partially conducted in a shear ^¬ socket (16), said shear connector (16) projecting, preferably annular collar extension (18) has a from the first valve head part (10) to which a pot (at least 40 ) is releasably attachable.

Tow bar according to claim 1,

characterized in that

on the outer side of the first valve head part (10) an adapter element (50) is provided through which Wenig ^¬ least extends a shear bolt (30) and on which the Wenig ^¬ least one collecting basket (40) can be detachably fastened. Tow bar according to claim 2 or 3,

characterized in that

the collar extension (18) or the adapter element (50) ring ^¬ shaped and preferably a thread, further preference ^¬ an external thread, or a part of a Bajonettver closing, preferably at least one securing pin (19) of a bayonet lock, for releasable connection with the at least a collecting basket (40).

Tow bar according to one of claims 2 to 4,

characterized in that

the at least one collecting basket (40) for direct Ver ^¬ bond with the collar extension (18) or the adapter element (50) is designed to be suitable and preferably a Ge threaded ^¬, more preferably an internal thread, or part of a bayonet closure, preferably at least one guide slot of a Has bayonet closure

Tow bar according to one of claims 2 to 4,

characterized in that

for fastening the at least one collecting basket (40), a catching ring (41) encompassing the collecting basket (40) is provided which is designed to be detachable with the collar extension (18) or the adapter ring (50) and preferably a thread, more preferably one In ^¬ nengewinde, or a part of a bayonet closure, preferably at least one guide slot (42) of a bayonet closure comprises.

Tow bar according to claim 6,

characterized in that

between the at least one collecting basket (40) and union ^¬ ring (41) is provided a spring element (43) which is preferably annular.

8. tow bar according to claim 7,

characterized in that

the spring element (43) is an elastomeric ring or a wave spring, preferably made of metal.

9. Towing bar according to one of the preceding claims, characterized in that

the at least one collecting basket (40) is at least partially transparent.

10. tow bar according to claim 9,

characterized in that

the collecting basket (40) made of translucent plastic, a flexible net or a wire mesh, where in the mesh of the network or the wire mesh is preferably greater than or equal to 1.5 mm.

11. tow bar according to one of the preceding claims, characterized in that

more than one shear bolt (30) is provided, wherein for each shear bolt (30) in each case at least one collecting basket (40) is provided.