FI71539C - BOMSYSTEM CONSTRUCTION FOER ARBETSMASKIN - Google Patents

Description

1 71539

MACHINE BOOM STRUCTURE - BOMSY3TEMKONSTRUKTION FÖR ARBETSMASKIN

The invention relates to a boom structure for a working machine as defined in the preamble of claim 5.

Trucks, tractors and forestry machines currently use boom cranes consisting mainly of an articulated boom attached to the implement and a folding boom 10 articulated to one end of the boom, to the other end of which various work equipment can be attached for different work tasks. In order to increase the working area, the extension of the lifting device, a telescopic extension is often connected to the folding boom, by means of which an increase of about 50% of the length of the folding boom is obtained.

It is also known to extend the length of the boom with an extension boom articulated to the folding boom and further with an extension arm 1a articulated to this, whereby the boom 20 consists of four parts articulated to each other. Prior art refers to U.S. 2,598,517, U.S. 3,221,908, U.S. 3,253,716 and U.S. 3,557,967.

The dimension of the stand can, of course, be increased by extending the length of its parts. In this case, however, the device 25 becomes too heavy to be mounted on lightweight host line grapple loaders and the like. Such heavy, far-reaching, known boom structures are only available on heavy-duty implements.

The object of the invention is to eliminate the above-mentioned drawbacks. In particular, the object of the invention is to provide an inexpensive, simple and light machine boom structure which can also be mounted on light host line machines, e.g. grapple loaders and tractors, and which has an almost two- to 35-fold increase in scope compared to known light machine equipment.

For features characteristic of the invention, '71539 refers to the claims.

In addition, in the boom structure according to the invention, it is possible to use already known extensions which can be connected to the extension arm and which act scopically, by means of which the dimension of the boom can be further increased. According to the invention, the boom structure comprises a t.uk device by means of which the boom structure can be supported on the ground during work. The support device can be supported, for example, on the rear side or on the extension boom.

An advantage of the invention over the prior art is that, for example, when collecting trees from the forest, the damage to the nursery is reduced, because the tracks are not created as often as when working with conventional equipment. Likewise, due to the light structure and mode of operation of the boom, even lighter machines can be used.

The invention will now be described in detail with reference to the drawing, which shows a boom structure according to the invention.

The device 20 according to the invention shown in the figure comprises a lifting boom 1, which can be attached to the working machine to be used at one end by a known technique. At the other end of the lifting boom there is an articulated folding boom 3, which can be moved relative to the lifting boom 1 by a power device 2, a hydraulic cylinder. An extension boom 4 is articulated to one end of the folding boom 3 at its other end so that the extension boom 4 is movable relative to the folding boom 3 on their common joint 11 by a force device 7, a hydraulic cylinder, which is hingedly connected to the folding boom and extension boom. An extension arm 5 is connected to one end of the extension boom 4 by a joint 12 at its other end. The extension arm 5 can be moved relative to the extension boom 4 on a joint 12 by means of a force 1 by means of a device 8, a hydraulic roller. At the other end of the extension arm 5 there is mounted a log grapple 6 operating in a manner known per se. The device further comprises a support device 10 according to the invention when the extension boom 4 is working against the ground.

II

3 in 71539. In this way, the extension boom 4 can be firmly placed against the ground, even in soft ground.

The device according to the invention shown in the figure operates as follows. With light equipment from the forest when harvesting trees 5, the lifting boom 1 and the folding boom 3 are extended towards the frames to be collected so that the other, outer end of the folding boom 3 is finally pressed against the ground. Then, with the power device 7, the extension boom 4 and with the power device 8, the extension arm 5 is extended towards the timber 10 to be assembled, and with the log grapple 6 they can be picked up. Despite the long arm of the machine, the implement is not affected by large tilting forces, because the machine rests firmly on the ground via the support plate 10. In this case, no additional support sensors are required, which are common in current lifting equipment and work machines using the equipment.

The invention is particularly well suited for lightweight agricultural tractors for use in host line forestry work. However, the invention is not limited to this field of application, but it is also possible to use it in machines of a more robust class, as well as in trucks of various sizes and the like. The power devices of the boom structure are hydraulic cylinders known per se, the pressure hoses of which are attached and run along the frame 1, 3, 4 of the frame-25.

Likewise, the log grapple 6 at the end of the extension arm 5 is a device operating in a known manner, which can also be replaced by various other working devices. Thus, the above application and mode of operation of the boom structure according to the invention do not in any way limit the invention and its use, but the different embodiments of the invention may vary within the scope of the inventive idea set out in the claims.

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Claims (2)

71539 A boom structure for an implement, the structure comprising a lifting boom (1) attached to the implement at one end; a folding boom (3) articulated at one end of the lifting boom and movable by a power device (2); an extension boom (4) articulated to one end of the folding boom (3); an extension arm (5) articulated to one end of the extension boom, to the other end of which known working devices, such as a log grapple (6), operating in a manner known per se, can be connected; a power device (7) articulated to the folding boom (3) and the extension boom (4) for moving the extension boom relative to the folding boom; and a power device (8) articulated to the extension boom (4) and the extension arm (5) for moving the extension arm relative to the extension boom, characterized in that the boom structure includes a support device based on the folding boom or extension arms to support the boom during paint work. Structure according to Claim 1, characterized in that the support device is a support plate (10). 25 11