Patent Application
20170129539
The invention relates to a transport vehicle, in particular a self-propelled transport vehicle, having a chassis with at least two load carriers being arranged side-by-side and spaced from each other, whose mutual distance is, for changing the width of the transport vehicle, changeable.
For transporting loads having an excess width or for the return journey of the transport vehicle without load respectively, it is of advantage that the width of the vehicle used for transporting a heavy load can be changed. In addition, in some states of the USA special legal provisions for vehicles for transporting heavy loads are in force, by which the allowable load per axle is, depending on the track width of the vehicle, limited, so that a variable width and hence a track width is of advantage in order to comply with the legal regulations and to exploit the maximum axle load. For this purpose it is provided in the known transport vehicle that between the two parallel load carriers a central carrier is arranged and that the two load carriers are connected with the central girder by means of cross beams being variable in their length. By way of a corresponding displacement of the load girders it is therefore possible to change the width of the known transport vehicle and hence its track width.
From WO 2010/048674 A1 a transport vehicle is known, which comprises two juxtaposed load girders spaced apart from each other, whose mutual distance can be varied for changing the width of the transport vehicle. Between the two load girders an X-shaped connecting element is arranged, which comprises two beams being connected by a joint arranged in the middle. The first beam runs from a front portion of the first load girder to the end portion of the second load girder, the second beam runs from a front portion of the second load girder to a rear portion of the first load girder, so that the two beams cross in their middle and are connected via a hinge. Each of the two beams is connected with the rear portion of the respective load girder and is received pivotally and slidingly in guide elements, so that they are movable along the load girder. If the two load girders are moved apart, the front ends of the two beams move along the guide elements towards the rear end of the load girders, so that the X defined by the two crossing beams broadens. For reducing the width of the vehicle the front portions of the beams are slided forwardly, so that the X defined by the crossing beams narrows.
From WO 96/39320 A1 a wheel chair is known, in which the aforementioned designed principle is realized too. This wheel chair has got two longitudinal frames, between which two beams are arranged in an X-configuration. Each front end of the crossing beams is arranged in the respective longitudinal frame slidingly and the rear part of the two beams is connected firmly with the respective longitudinal frame.
From U.S. Pat. No. 4,221,398 a transport vehicle of the type mentioned afore is known, having the form of a drawbar trailer and a low loader with several steering axles, whose width and track width can be increased and decreased when required, by moving two chassis parts, each having a row of wheel bogies, transverse to the direction of travel or to a vertical longitudinal central axis respectively, apart or together. The wheel bogies of each steering axle are steered there independently by separate steering cylinders, which are arranged in each of the two chassis parts.
Furthermore, from U.S. Pat. No. 4,772,038, U.S. Pat. No. 5,118,245 or U.S. Pat. No. 5,326,128 transport vehicles with a variable width and track width are known. U.S. Pat. No. 3,339,942 discloses a low loader with variable track width, whose width can be reduced when driving unloaded.
DE 2 219 447 A discloses a transport vehicle in the form of a low loader consisting of two traverses or load carriers, each carrying a row of successively arranged steerable wheel bogies, and two traction units. To steer the wheel bogies of both traverses simultaneously, in total four lockable and telescopable (i.e. capable of telescoping) track rods are provided, which are arranged in pairs between each of the traction units and the wheel bogies of the adjacent steering or pendulum axis. However, this means that at any adjustment of the width and the track width of the low loader the length of all four telescopable track rods must be adjusted and locked after this adjustment, which causes significant setup times. In addition, the telescopable track rods are arranged in respect to the longitudinal vehicle axis at an angle of other than 90 degrees, which also changes when adjusting the width and the track width of the low loader, so that the amount of the length adjustment of the track rods necessary does not correspond to the amount of the adjustment of the track width, but must be calculated for the different track width depending on the angular position of the track rods. In addition, the turning movement of a tractor unit results in different angular orientations of the track rods being arranged on both sides of the traction unit, so that for transmitting the pivotal movement of the traction unit to the two wheel bogies of the adjacent steering or pendulum axle it seems doubtful whether or not the steering angle of these two wheel bogies is identical, despite of a relatively complicated kinematics.
It is the object of the present invention to further develop a transport vehicle, in particular a self-propelled transport vehicle, of the kind mentioned at the beginning in such a way that a width and consequently a track width adjustment is possible in a simple way.
This object is achieved by the present invention that at least two load carriers of the transport vehicle are connected by a scissor link, that at least one scissor link comprises two arms, whose first end portions are hingedly connected with one load carrier and whose second end portions are connected via a joint, that at least one scissor link comprises two arms, so that the first end portion of the first arm is pivotally connected with the first end portion of the first arm and the first end portion of the second arm of said scissor link is pivotally connected with the second load carrier, so that the second end portion of the first arm and the second end portion of the second arm are connected via a joint.
It is understood by those skilled in the art that the use of the term “load carrier” can be used interchangeably with the term “load girder” as they mean and teach the same concept of a girder/carrier that can accommodate a load.
By the inventive measures in an advantageous way a transport vehicle is created, which is variable in its width and hence in its track width, which is characterized in that this width adjustment can be performed with simple means, namely with scissor links. In an advantageous way the two load carriers of the transport vehicles being connected by the scissor links are only connected by the scissor links and, preferably, by a cross beam being variable in its length. The design of the wheel arrangements carrying the load carrier is therefore not affected by the width and track width adjustability achieved by the inventive measures.
An advantageous further development of the invention provides that at least one, preferably all or almost all wheel assemblies of the transport vehicle are designed steerable. Such a measure has got the advantage that the width adjustment of the inventive transport vehicle can be achieved by a respective positioning of the wheels of the wheel assemblies in conjunction with a subsequent driving movement of the transport vehicle.
A further advantageous further development of the invention provides that the transport vehicle has at least one means for changing the angular position of the arms of the corresponding scissor link, which engages on at least one scissor link. Preferably it is provided that this means, in particular a double-acting cylinder, is arranged between two cooperating scissor links, so that by acting on the scissor links an adjustment of the distance of their pivot points in the direction of the load carriers can be achieved. The change of the angular position of the arms of the scissor links caused in that way results in an advantageous manner in a change of the width of the transport vehicle.
Further advantageous developments of the invention are the subject matter of the depending claims.
Further details and advantages of the invention are disclosed in the exemplary embodiments, which are described in the following with reference to the two exemplary embodiments. It shows:
In
The transport vehicle 1 comprises a chassis 2, which has two load carriers (i.e. load girders) 2a, 2b, which are arranged spaced apart and can be moved relative to each other in a transverse direction. Preferably, they are constructed identically, so that in the following only the load carrier 2a, which is the right one in
It is essential that the two load carrier 2a and 2b of the chassis 2 are connected by two scissor links 4 and 5 with each other, each having two arms 4a and 4b and 5a and 5b respectively. A first end portion 4a′ and 4b′ respectively of the arms 4a and 4b of the first scissor link 4 is—as best seen from
The load carriers 2a and 2b are connected firmly via a cross beam 2c, whose length can be varied, so that the stability of the vehicle 1 is enhanced.
The joints 8 comprise a means 10 for defining the angular position of the arms 4a-5b of the scissor links 4 and 5 in respect to the load carriers 2a and 2b. This one has got a perforated plate 11, which has got openings 12 forming a hole pattern, which are arranged concentrically to the pivot axis of the joints 8 provided by the bolts 8d. Each arm 4a, 4b and 5a, 5b of the scissor links 4 and 5 comprises a recess 13, which is arranged in such a way that a bolt 14 put through one of the openings 12 of the hole pattern enters the corresponding recess 13 of the respective arms 4a, 4b, 5a, 5b and hence fixes the arm 4a, 4b, 5a, 5b in its angular position corresponding to the respective opening of the hole pattern.
The width adjustment of the described vehicle 1 is now performed as follows: Firstly, the bolts 14 are removed, so that the arms 4a, 4b and 5a, 5b of the scissor links 4 and 5 are not fixed in their corresponding angular position any longer. If the load carriers 2a and 2b are to be moved from their broader position shown in
The moving apart of the load carriers 2a and 2b is done correspondingly: After the locking elements of the means 10, i.e. in this case the bolts 14, have been removed, the steering axles of the wheel assemblies 6 are positioned in such a way that the dual wheels 3a—seen in the aforementioned direction of travel—are arranged running spread apart. If now the transport vehicle 1 is moved in said direction, the wheels 3a move outwardly, so that the load carriers 2a and 2b are moved apart from each other. After the desired width has been reached, the bolts 14 are put into the corresponding openings 12 of the hole patterns 11. In this way a fixation of the scissor links 4 and 5 in respect to their angular position and hence to the distance between the load carriers 2a and 2b is achieved.
It is possible too, that the transport vehicle 1 comprises means known to the person skilled in the art and hence not shown, e.g. hydraulic or pneumatic cylinders, which act in traverse direction onto the load carriers 2a and 2b, in order to change the angular position of the arms 4a, 4b and 5a, 5b of the two scissor links 4 and 5 and the load carriers 2a and 2b by these means.
It is possible to that between the scissor links 4 and 5 a corresponding device 20 is arranged, by which the longitudinal distance between the joints 4c and 5c of the scissor links 4 and 5 can be changed, thus resulting in an adjustment of the angular positions of the arms 4a, 4b and 5a, 5b of the scissor links 4 and 5 and hence of the distance between the two load carriers 2a and 2b. In the second exemplary embodiment shown in
In the above description it was assumed that the chassis 2 of the transport vehicle 1 only has got the two load carriers 2a and 2b connected by the scissor links 4 and 5. It is possible too to cascade the previously described arrangement, e.g. that besides the two previously described load carriers 2a and 2b connected via the scissor links 4 and 5 at least one further load carrier of the chassis 2 is provided, which is once more connected via further scissor links with the load carriers 2a and 2b respectively. It is possible to provide more than three load carriers 2a and 2b and to connect adjacent load carriers via scissor links 4 and 5.
In the above description, it was assumed that between adjacent load carriers 2a and 2b two scissor links 4 and 5 are arranged. This is not mandatory, but it is possible only to provide only one scissor link 4 or 5 between the two load carriers 2a or 2b, although this is not preferred. When using long load carriers 2a and 2b it is of advantage to provide more than two scissor links 4 and 5.
The provision of the wheel assemblies 3 of the transport vehicle 1 with corresponding steering axles is preferred, since this is a particular simple and elegant way to change the distance between the load carriers 2a and 2b and hence the width of the transport vehicle 1 via a corresponding driving movement. But this is not mandatory. It is, e.g. possible to apply a force on the scissor links 4 and/or 5 by means of a side impact of one or both load carriers 2a and/or 2b, which results in a change of the angular position of the load arms 4a, 4b and/or 5a, 5b and hence a change of the distance between the load carriers 2a and 2b. Here, the dual wheels 3a of the wheel assembly 3 are de facto pushed over the ground bearing the transport vehicle 1.
In conclusion, it must be stated that by the measures described a transport vehicle 1 is provided, which is characterized by its simple width and hence track width adjustment. By providing that at least two load carriers 2a, 2b of the chassis 2 of the transport vehicle 1 are connected via one or several scissor links 4, 5 with each other, the distance of the corresponding load carriers 2a and 2b can be increased or reduced by a simple driving movement of the transport vehicle 1 in connection with appropriately build wheel assemblies 3.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2014 009 036.1 | Jun 2014 | DE | national |
| 20 2014 005 055.4 | Jun 2014 | DE | national |
This continuation application claims priority to PCT/EP2015/001223 filed on Jun. 17, 2015 which has published as WO 2015/197173 A1 and also the German application number 10 2014 009 036.1 filed on Jun. 24, 2014 and application number 20 2014 005 055.4 filed on Jun. 24, 2014, the entire contents of which are fully incorporated herein with these references.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/EP2015/001223 | Jun 2015 | US |
| Child | 15381557 | US |
