The invention relates to a pontoon crawler track assembly, which is intended to be used as a crawler- track-driven undercarriage in a working machine, such as an excavator, a drilling or a piling machine or like, operating particularly in water, which comprises a mounting frame and pontoon members. The mounting frame has coupling means to coupple the pontoon crawler track assembly with a working machine and fastening means for attachment of the box-structured, hollow pontoon members at the sides of the mounting frame. Each pontoon member is equipped with a crawler track arrangement, which is arranged moveable by way of an internal power transmission arrangement. Furthermore the breadth of the pontoon crawler track assembly is arranged adjustable.

It is nowadays known to use a pontoon crawler track assembly as described above as a crawler-track-driven undercarriage particularly in working machines operating in water, such as excavators. A working machine, being equipped like this, is transported to its operating site usually by road as a so called extra wide transportation, which always requires extra arrangements including separate warning vehicles etc. After the operation the working machine is being returned to its maintenance point, whereby a usual undercarriage is being replaced to the same, in case the next operation is related to usual ground excavation. This is why the measures related to a preliminary preparation and transportation of a working machine, being utilized in water, are first of all very laborious to perform and on the other hand get disproportionately expensive particularly due to those special arrangements needed for road transportations. Furthermore in patent US 6, 315,622 there has been presented a pontoon crawler track assembly suitable for the above purpose, which comprises a mounting frame, which is put together from parts in a way that it includes a middle part, to be attached e.g. to a fastening beam of an excavator, and furthermore fastening parts, to be attached to the ends of the middle part by screw joints, in order to fasten the actual pontoon members equipped with crawler tracks. One meaning of the above solution is that by altering particularly the lengths of the fastening parts for the pontoon members, it is possible to vary the breadth of the pontoon crawler track assembly, acting as an undercarriage of an excavator, to be most suitable for each purpose.

The solution according to US patent 6,315,622 does not bring about any significant advantage with respect to the problems, being explained before, because it is based on the fact that the undercarriage must be first of all put together manually from separate parts by applying several bolt joints, which must be carried out in practice usually indoors. On the other hand it must still be transported separately in its operating breadth to an installation site or together with the excavator, while being attached to the same. This is why, also in connection with this type of solution, there is still a need to use extra wide road transportations. In addition to that, for each differing operating breadth of the undercarriage, fastening parts having deviating measures must be manufactured/stored.

It is an aim of the pontoon crawler track assembly according to the present invention to achieve a decisive improvement in the problems described above and thus to raise essentially the level of prior art in the field. In order to achieve this aim, the pontoon crawler track assembly according to the invention is primarily characterized in that it has actuators for adjusting its breadth in a way that a working machine equipped with a pontoon crawler assembly may be brought, by changing the distance between its pontoon members by means of said actuators, operating by auxiliary power, first of all into a narrowed position particularly with a view to road transportation or the like and on the other hand into a broadened position particularly with a view to operating in water.

As the most important advantages of the crawler track assembly according to the invention may be mentioned simplicity and efficiency of its structure, manufacturing and use, whereby with very simple technical solutions it is possible to put together a pontoon crawler track assembly, which can, when being attached to the working machine, first of all be adjusted to a desired optimum operating breadth at any given time and on the other hand be narrowed to its minumum breadth in a way that e.g. in road transportations of the working machine traffic arrangements are not needed, which is the case with extra wide transportations. This is based on the fact that extremely simple structures have been utilized in the pontoon crawler track assembly particularly for the part of the power transmission arrangements moving the crawler track arrangements of the pontoon members so that for their part it is possible to achieve significant cost savings from the point of view of manufacturing. This has been achieved by using in each pontoon member only one power transmission arrangement, being placed essentially at the center of the pontoon member and in which each crawler track part of the crawler track arrangement is attached to the power transmission chain from its middle. As an advantageous embodiment, the crawler track arrangement comprises furthermore shorter and longer crawler track parts that are arranged in a way that the mutual distance of the longer crawler track parts from each other in the longitudinal direction is greater than the total length of the mounting frame, which arrangements together with a cavity, existing in the internal side wall of the pontoon member, enable withdrawing of the mounting frame partially inside the pontoon member between the first crawler track parts. In usual crawler track solutions there has been used traditionally two power transmission arrangements, being placed at opposite edges of the crawler track frame, between which the crawler track parts have been fastened, which does not enable withdrawing of the fastening frame inside the pontoon members. On the other hand according to the invention it is also possible to arrange the pontoon members to move simultaneously downwards during the sideward movement by means of the fastening beams, being placed in inclined positions, which enables adjustment of the operating height of the working machine.

One crucial advantage of the pontoon crawler track assembly according to the invention is thus the adjustment of the operating breadth of the undercarriage, whereby those manual installation stages and extra spare parts, required by e.g. the solution according to US patent 6,315,622, may be totally avoided thanks to hydraulic cylinders, to be controlled advantageously from the the working machine's cab and operated by means of the operating machine's hydraulic system. The efficiency of the hydraulic cylinders may be optimized particularly thanks to the fact that the forces needed for adjustment may be minimized by lifting the pontoon member, to be adjusted at any given time, e.g. by means of the bucket of the excavator, operating as the working machine, prior to its positioning.

Advantageous embodiments of the pontoon crawler track assembly according to the invention are presented in the dependent claims related to the same.

In the following description the invention is depicted in greater detail with reference to the attached drawings, whereby in

figure 1 is shown an exemplary perspective view of a working machine equipped with a pontoon crawler track according to the invention,

figure 2 is shown as a perspective view an advantageous composition of a pontoon crawler track assembly according to the invention,

figure 3 is shown an advantageous operating principle of a power transmission arrangement of a pontoon member, belonging to the pontoon crawler track assembly according to the invention,

figure 4 is shown as a perspective view a pontoon member belonging to the pontoon crawler track assembly according to the invention, from which the lowermost skin plates of the crawler track arrangement are missing,

figures 5a and 5b is shown as a perspective view seen from the front an auxiliary pontoon arrangement, being utilized as an advantageous embodiment in the crawler track assembly according to the invention, and a pontoon crawler track assembly according to the invention,

figure 6 is shown as a perspective view an auxiliary pontoon belonging to an auxiliary pontoon arrangement as seen from its external side, and

figure 7 is shown as a perspective view furthermore a pontoon crawler track assembly embodiment enabling adjustment of the operating height of the working machine.

The invention relates to a pontoon crawler track assembly, which is intended to be used as a crawler- track-driven undercarriage in a working machine T, such as an excavator, a drilling or a piling machine or like, operating particularly in water, which comprises a mounting frame 1 and pontoon members 2. The mounting frame 1 has coupling means Ia to couple the pontoon crawler track assembly with the working machine T and fastening means Ib for attachment of the box-structured, hollow pontoon members 2 at the sides of the mounting frame 1. Each pontoon member 2 is equipped with a crawler track arrangement 2b, which is arranged moveable by way of an internal power transmission arrangement 2a. Furthermore the breadth of the pontoon crawler track assembly is arranged adjustable. With reference e.g. to figures 1, 2 and 5b, the pontoon crawler track assembly has actuators 3 for adjusting its breadth in a way that a working machine equipped with the pontoon crawler track assembly may be brought, by changing the distance between its pontoon members 2 by means of said actuators, operating by auxiliary power, first of all, as shown particularly in fig. 5b, into a narrowed position Hl particularly with a view to road transportation or the like and on the other hand into a broadened position H2 particularly with a view to operating in water.

The power transmission arrangement 2a, existing in the pontoon crawler track assembly, comprises, on the principle shown in figure 3, an endless power transmission means 2al in each of its pontoon member 2, such as a chain, formed by pin joints of successive formed parts and that is arranged moveable by means of a wheel arrangement 2a2, such as a drive wheel 2a2' and a turnover wheel 2a2" and/or a support wheel arrangement 2a2'" or like, on the outer periphery of the pontoon member 2, whereby each successive crawler track part belonging to the crawler track arrangement 2b is attached to the endless power transmission means 2al. With reference particularly to the general principle shown in figure 3, the pontoon crawler track assembly according to the invention comprises one power transmission arrangement 2a, being placed essentially at the center of each pontoon member 2, whereby each crawler track part of the crawler track arrangement 2b is coupled with the power transmission means 2al essentially from its middle. The power transmission arrangement comprises usually also chain tightening arrangements 2a2"" as shown in figure 3.

Particularly as shown in figures 1, 2 and 5b, the crawler track arrangement 2b is formed of first crawler track parts 2bl and second crawler track parts 2b2, the second parts 2b2 of which are essentially shorter than the first crawler track parts 2bl when viewed in a transverse direction p. Furthermore with reference particularly to figure 2, the longitudinal s distance e between the first crawler track parts 2bl is essentially greater than the total length L of the mounting frame 1, which together with a cavity 2y, existing in the internal side wall 2s of the pontoon member 2, enables withdrawing of the mounting frame 1 partially inside the pontoon member 2 between the first crawler track parts 2bl.

On the other hand as an alternative solution with respect to the above solution, which gets broadened essentially horizontally, in the solution shown in figure 7 the pontoon members 2 of the pontoon crawler track assembly are arranged moveable in the transverse direction p in an angle a deviating essentially from horizontal plane, which makes possible particularly adjustment of the operating height of the working machine.

Particularly with reference to figures 3 and 4, the fastening means Ib are arranged by attachment beams IbI, being attached to the pontoon members 2 and that may be coupled with the mounting frame 1 in a way enabling their mutual longitudinal p movement w, such as on telescope or slide rail principle or accordingly.

Furthermore as an advantageous embodiment the actuators 3, belonging to the pontoon crawler track assembly for adjustment of its breadth, are arranged by hydraulic cylinders 3a, which are particularly with reference to figure 2 in a power transmitting connection with the mounting frame 1 and the pontoon members 2 and the amount of which corresponds to the amount of attachment beams IbI, profitably two pieces per pontoon member 2.

Furthermore as an advantageous embodiment, the pontoon crawler track assembly comprises an auxiliary pontoon arrangement 4 in order to increase the carrying capacity of the pontoon crawler track assembly. With reference particularly to figures 5a, 6 and 7 the auxiliary pontoon arrangement 4 comprises an auxiliary pontoon 4a, 4a' to be connected preferably on quick- release principle such as by fastening lugs pi and lock fittings p2 in connection with each pontoon member, such as at its outer surface 2u and/or above the same (see fig. 7) . When taking advantage of auxiliary pontoons 4a' to be placed above e.g. as shown in figure 7, they may be installed in their places only in an adequately outward driven positions of the pontoon members 2.

One or several pontoon members 2 of the pontoon crawler track assembly is/are as an advantageous embodiment provided with an anchoring arrangement 4al, which comprises one or several support beams or like for supporting the bottom of the pontoon crawler track assembly at the bottom and that are operated by auxiliary powered driving means 5 that move the same in respect with the auxiliary pontoon 4a in its direction of height h, and/or with a propeller arrangement for independent moving and enabling the operation of the pontoon crawler track assembly in open water.

Furthermore as an advantageous embodiment the pontoon crawler track assembly comprises a control arrangement X, by means of which use of the actuators 3, the driving means 5 and/or the propeller arrangement is enabled remotely, such as from the working machine's cab or correspondingly. Furthermore a hydraulic system of the pontoon crawler track assembly, such as functioning of the actuators, the driving means 5 and/or the propeller arrangement is arranged profitably by power influence transmitted from the hydraulic system of the working machine T.

Furthermore as an advantageous embodiment, the pontoon members 2 are e.g. as shown in figure 4 arranged as partitioned structures by means of compartmentation walls vs, which make sure adequate supporting capacity of the pontoon crawler track assembly inspite of a local damage in the casing of its pontoon member.

Particularly with a view to Nordic countries, the total length of a pontoon crawler track assembly according to the type described above is in usual applications generally approximately 10040 mm at its maximum. Correspondingly the breadth of the pontoon members is advantageously approximately 1550 mm, whereby when using a fastening frame, the breadth of which is approximately 1200 mm, the mimimum breadth of the pontoon crawler track assembly in its narrowed position is approximately 3490 mm, which remains below a measure (3005 mm), which e.g. in Finland requires extra wide transportation. Furthermore as depicted above, the pushing force of the hydraulic cylinders, being utilized for adjustment of the breadth of the crawler track assembly, is at its maximum approximately 10000 Newton, which is particularly thanks to the fact that during adjustment of the breadth of the pontoon crawler track assembly e.g. the bucket of an excavator may be exploited, by means of which the side of the undercarriage to be adjusted each time is being lifted up from the ground prior to adjustment of the operating breadth, which minimizes significantly the need for power. Naturally the adjustment of breadth in water takes place easily by adjustments to be performed simply from the cab of the working machine.

It is obvious that the invention is not limited to the embodiments presented or described above, but it can be modified within the basic idea according to the needs and applications needed at any given time. Thus it is naturally clear, that e.g. the coupling means of the working machine as well as the fastening means between the pontoon members and the fastening frame may be carried out by arrangements deviating from those, being presented above. The fastening means may thus be carried out e.g. in a way that the fastening beams, existing in opposite pontoon members, are not actually inside each other. In addition to the above, the fastening arrangements between the auxiliary pontoon arrangement and the pontoon members may be carried out instead of quick-release principle e.g. by usual bolt joints or instead e.g. by certain kind of edge lockings. Additionally the power transmission arrangement in each pontoon member may also be carried out in other ways than on the directive operating principle shown in the attached drawings. Additionally it is naturally possible to equip also the pontoon members with propeller arrangements or provide the auxiliary pontoons correspondingly with partitioned structures.