Patent Description:
Various stump-grubbing harrows are known. They are intended to scrape ground to loosen stumps, root clumps, and stones, for example, when clearing land for cultivation. Stump-grubbing harrows can be attached, for example, to the end of set of booms of an excavator, the harrow being operated by using the set of booms. If necessary, a stump-grubbing harrow can also be used for scarifying. A stump-grubbing harrow is typically formed of set of curved claws arranged in rows, using the points of which the aforementioned operations are carried out. However, a stump-grubbing harrow cannot be used to perform, for example, effective and precise materials handling, i.e., for example, moving objects from one place to another.

Further, more developed means are known, especially for handling stumps. One example is the device marketed by Tervolan Konepaja Oy under the product name Pallari, which the manufacturer calls a stump harvester. It too can be attached to the end of set of booms of an excavator. The stump harvester is designed especially for stump lifting and particularly for chopping them. It can be used to lift stumps from the ground and/or to chop them already in the ground or when lifted from it.

The stump harvester is formed, for example, of two fixed claws arranged next to each other with a claw moveable against them, which is arranged to go between the fixed claws. The cutting claw thus acts as a moveable jaw and also as a blade. The object, i.e. the stump, or part of it intended to be processed by the device can be pressed between the moveable claw and the fixed claws. In addition, the stump harvester can also be used to break up tussocks. For that a fixed tussocking element is integrated on the opposite side of the fixed claws to the moveable claw. It can be used to push the ground open.

Another stump harvester is known from Finnish patent application publication number <CIT>. Stump harvesters are characterized by a great power output requirement. The same also applies to various crushing grabs, in which in addition to a moveable jaw, crushing is often further boosted by an impact device implemented, for example, as a hydraulic hammer. In the latter of the two aforementioned stump harvesters, the great power output is obtained using a moment arm. This is located between the end of the operating element of the hydraulic actuator and the moveable claw. An adjustable moment is obtained by means of a moment arm arranged with a changeable angle attitude. However, stump harvesters can only be used to perform the effective and precise processing of stumps. Examples of other work are the lifting and transfer of stones from one place to another. Which is even less successful using a crushing grab.

Various grabs, which are also called grab buckets, are also known. They are intended especially for material handling. They include two moveable jaws, which can be arranged opposite each other. Both of the jaws are then pivoted rotatably, so that the grab can be closed and opened. The grab is typically used to grip the object to be handled, move it to another location, and release the object. The object to be moved is thus gripped by the grab, and pressed between its jaws. The grab cannot, however, be used, for example, to effectively handle stumps, such as lifting them, or for soil tilling.

If it is wished to perform all these operations efficiently and well, for which the aforementioned tools and devices are intended, then all of the aforementioned tools will be required. The threshold in investing in all of them may be high and, on the other hand, when not used the acquired tools will also tie up capital. The logistics relating to the devices also creates its own special challenge. In the worst case, all the tools may be needed at the same work site, to perform the work efficiently and well. In addition, switching from one tool to another between different tasks takes time and reduces effective and productive operation, even though the work machine and tools are equipped with quick connectors.

<CIT>, <CIT> and <CIT> disclose different examples of multi-purpose work devices with different types of grabs.

The invention is intended to create a multi-purpose work device. The characteristic features of the work device according to the invention are stated in Claim <NUM>.

The work device according to the invention can be said to be suitable not only for compromise-free grab operation, but also for tearing, separating, and demolition, for collecting the material being handled without grab operation, and even for soil tilling. This is all made possible by the fixed jaw and the jaw arranged to move relative to it, arranged to form a grab. The fixed jaw can be made sufficiently strong, for example, for soil tilling and material handling take place by "shovelling", i.e. for transfer taking place by pushing the material. According to one embodiment, the moveable jaw can, in turn, be narrower than the fixed jaw. This improves the visibility of the material being processed and the processing object. In addition, the moveable jaw can, if necessary, be turned out of the way when not needed, using an arm mechanism arranged for it, making unobstructed operations with the fixed jaw of the work device possible. The moveable jaw can even be turned out of the way in a selected direction.

The work device includes a wide-angle pivot setup for the moveable jaw. This is implemented by an arm mechanism equipped with two pivots between the hydraulic actuator and the moveable jaw. The arm mechanism with two pivots is then arranged to form a wide-angle pivot. The magnitude of the rotation angle of the movement created for the jaw arranged to move by the wide-angle pivot is more than <NUM>°. The straight movement created by the hydraulic actuator is converted into a wide rotation movement of the moveable jaw with the aid of the wide-angle pivot setup, which, the arm mechanism equipped with two pivots is arranged to form. Thanks to the arm mechanism, more generally the wide-angle pivot setup, the moveable jaw, for example, from its base part, is made even mainly parallel to the hydraulic actuator, at both extreme ends of the movement of the jaw. This is when the grab is fully opened as an extension of the hydraulic actuator as well as also when the grab is fully closed and mainly parallel to the hydraulic actuator.

The wide-angle pivot setup includes, in addition to an arm mechanism equipped with two pivots, the jaw arm, a lever arm arranged to rotate. The lever arm is fitted between the jaw arm and the body, to change the movement of the moving operating element of the hydraulic actuator into a rotational movement of the jaw arranged to move. At one end, the lever arm is pivoted to the body of the device. According to one embodiment, the lever arm is pivoted at the other end to the same pivot point from which the jaws arm is attached to the operating element of the hydraulic actuator. The other additional advantages obtained through the invention appear in the description portion, and its characteristic features are stated in the accompanying Claims.

The invention, which is not restricted to the embodiments presented in the following, is described in greater detail with reference to the accompanying Figures, in which.

<FIG> show an example of the work device <NUM> according to the invention. <FIG> shows an angled view of the work device <NUM>, <FIG> a top view of it, and <FIG> a side view seen from the side of the fixed jaw <NUM>. The work device <NUM> includes, as basic parts, a body <NUM>, a pair of jaws <NUM> arranged to form a grab <NUM>, and a hydraulic actuator <NUM> for the grab <NUM>, i.e. for opening and closing it.

The body <NUM> of the work device <NUM> is equipped with an attachment arrangement <NUM> to arrange the work device <NUM> at the end of a set of booms of the work machine (not shown). The work machine can be, for example, an excavator. The end of the set of booms of the excavator can be equipped, in an as such known manner, with a bucket rotation set of arms and an attachment interface for a work device. The set of booms includes, as is known, a main boom pivoted to the work machine, with an arm pivoted at its end, which is also often called an excavating arm. At its end is the attachment interface of the work device <NUM>, or at least part of it. At the end of the set of booms there can be a possible selected quick connector. By being equipped with a selected compatible counter-piece, i.e. an adapter, the work tool, such as, for example, a bucket, or now, in the case of the invention, a work device <NUM> according to the invention, can be detachably connected by its counter-piece to the quick connector, for example, without tools, and without the operator leaving the cab. The quick connector can be arranged directly in the pivot points of the bucket rotation at the end of the set of booms. On the other hand, it can also be in, for example, a rotator or a combination of a bucket rotator and a tilt, i.e. in a rototilt, as a part of them. The attachment arrangement <NUM> can, of course, also be fitted directly to the rotator, i.e. with no special adapters.

The body <NUM> is arranged to form a casing structure <NUM>. The casing structure <NUM> can be, for example, of sheet metal work. There can be stiffening casing beams in it. On the upper surface <NUM> of the casing structure <NUM> there is now an opening arrangement <NUM> as the attachment arrangement <NUM>. The opening arrangement <NUM> is arranged to be such that it is suitable for two or more quick-release attachment adapters, i.e. their counter-pieces to be connected to the work device <NUM>. Each counter-piece of adapter model can have its own opening in the opening arrangement <NUM>. The counter-piece is to be attached to the openings by, for example, bolts. Thus, thanks to the opening arrangement <NUM>, several different adapter models can be arranged for the work device <NUM>, with numerous different types available for excavators, or alternatively also for direct attachment to rotators, equipped with, for example, tilting.

With reference to <FIG> and <FIG>, a pair of jaws <NUM> is fitted to the body <NUM> of the work device <NUM>. The pair of jaws <NUM> includes two jaws <NUM>, <NUM> arranged to form a grab <NUM>. Both of the jaws <NUM>, <NUM> are now curved. The first of the jaws <NUM> forming the pair of jaws <NUM> of the grab <NUM> is fitted permanently in the body <NUM>, i.e. immovably relative to the body <NUM>. The body <NUM> continues in the lateral direction of the work device <NUM>, as a sheet-metal structure <NUM> on both sides of the casing structure <NUM>. The curved claws <NUM> belonging to the fixed jaw <NUM> are joined to the sheet-metal structure <NUM> at their roots <NUM>. Here the roots <NUM> can also be termed the cheek plate of the jaw <NUM>.

The roots <NUM> can include an extension <NUM>, <NUM>' arranged to continue under the body <NUM>. The extension <NUM>, <NUM>' is one way to continue the reach of the inner curve <NUM> of the jaw <NUM> over most of the grab <NUM> from its upper part. Thus, the share of the fixed jaw <NUM> is arranged to be more than half of the grab <NUM>. In addition, it can be stated that the inner curve <NUM> of the fixed jaw <NUM> is arranged to extend over most of the body <NUM>. The extensions <NUM>, <NUM>' can form zones laterally in the grab <NUM>. In the middle of the grab <NUM>, for example, in the area of the moving jaw <NUM>, the extension <NUM>' can be lower, thus forming a larger space in bottom of the grab <NUM> (<FIG> and <FIG>). On both sides of the moveable jaw <NUM> laterally in the grab <NUM>, the extensions <NUM> can, in turn, be higher (<FIG> and <FIG>) than in the middle area. The larger space in the middle of the grab <NUM> facilitates, for example, handling stones. The higher extension <NUM> at the sides of the grab <NUM> in turn facilitates handling longer objects (e.g., planks or pipes).

The other jaw <NUM>, arranged to form the grab <NUM>, is pivoted rotatably to the body <NUM>, to open and close the grab <NUM>. Thus the jaw <NUM> is fitted moveably to the grab <NUM> and body <NUM>. The movement is created by a hydraulic actuator <NUM>. Using it, the jaw <NUM> is rotated relative to the rotation pivot <NUM> arranged in the work device <NUM>. The fixing and integration of the other jaw <NUM> even as part of the actual body <NUM> creates a strong body for the work device <NUM>. The grab <NUM> will then withstand even violent torsion and hard work.

There are pivot-point openings <NUM>, <NUM> for the moveable jaw <NUM> in the body <NUM> of the work device <NUM> and in the moveable jaw <NUM> (or in the quick connector <NUM>, <FIG>, fitted rotatably for it in the body <NUM>), through which pivoting is achieved (<FIG> and <FIG>). The jaw <NUM> is connected to the body <NUM> (and to the aforesaid quick connector <NUM> arranged rotatably with it) by the pivot pin <NUM> (<FIG> and <FIG>) running through the openings <NUM>, <NUM>. The openings <NUM> are in lug plates <NUM> protruding from the body <NUM>.

The hydraulic actuator <NUM> is equipped with a moving operating element <NUM>. In this case the operating element <NUM> is formed by a piston rod <NUM>', arranged to move back and forwards in the hydraulic actuator <NUM>. The piston at its end is arranged to move back and forwards inside its cylinder part <NUM>*, due to the effect of a pressure medium, such as, for example, a liquid. At one end <NUM> the hydraulic actuator <NUM> is attached, in this case by its cylinder part <NUM>*, by a pin <NUM> (<FIG>) to a loop in the body <NUM> of the work device <NUM>. The operating element <NUM>, i.e. now the piston rod <NUM>', is arranged to act on the moveable jaw <NUM>, to open and close the grab <NUM>.

The operating element <NUM>, more generally the hydraulic actuator <NUM>, is arranged to act on one of the jaws <NUM> of the pair of jaws <NUM> forming the grab <NUM>, by means of a wide-angle pivot setup <NUM> belonging to the work device <NUM>. The rotation angle of the movement created by the wide-angle pivot setup <NUM> for the moveable jaw <NUM>, has a magnitude of more than <NUM>°. The angle can be defined from the moveable jaw <NUM>, for example, with the aid of two selected fixed points. The fixed points form straight lines and the angle between the straight lines is measured when the jaw <NUM> is in its extreme positions. Several significant advantages are achieved by the wide-angle pivot setup <NUM>, which, for example, increase the versatility of the work device <NUM> and work ergonomy.

According to one embodiment, the wide-angle pivot setup <NUM> can be formed by an arm mechanism <NUM> equipped with at least two pivots <NUM>, <NUM>. The arm mechanism <NUM> for opening and closing the grab <NUM>, by the movement of the moving operating element <NUM> of the hydraulic actuator <NUM>, is between the moving operating element <NUM> of the hydraulic actuator <NUM> and the moveable jaw <NUM>. In other words, to the moveable jaw <NUM> is arranged to be acted through the arm mechanism <NUM>. Thus, in the embodiment described, the moving operating element <NUM> of the hydraulic actuator <NUM> is not attached directly through a single pivot to the moveable jaw <NUM>, instead it is arranged to act on the moveable jaw <NUM> through the wide-angle pivot setup <NUM>, i.e., in the embodiment described, through the arm mechanism <NUM>. Action through the arm mechanism <NUM> can also be termed indirect.

An advantage of the arm mechanism <NUM>, more generally, of the wide-angle pivot setup <NUM>, is the large rotation movement created for the moveable jaw <NUM>, i.e. the large opening of the grab <NUM> (<FIG>) and also of the closing of the grab <NUM>, i.e. the rotation of the moveable jaw <NUM> to the roots of the fixed jaw (<FIG>). The wide-angle pivot setup <NUM> is arranged to create a rotation movement, i.e. a movement range, of the moveable jaw <NUM>, of a magnitude of, for example, <NUM>° - <NUM>°, <NUM>° - <NUM>°, more particularly <NUM>° - <NUM>°, and even more particularly <NUM>° - <NUM>°. In the Figures, the movement range of the moveable jaw <NUM> of the work device <NUM> shown as a one example is stated as a rotation angle of <NUM>°, which can be seen in <FIG>, <FIG> and especially in <FIG>. The angle can be measured, for example, using as an aid a straight line drawn through the rotation pivot <NUM> of the jaw <NUM> and the tubular shaft <NUM>, when the jaw <NUM> is in its extreme positions, i.e., the grab <NUM> fully open (<NUM>o, <FIG>) and the grab <NUM> fully closed (<NUM>c, <FIG>). The arm mechanism <NUM> equipped with two pivots <NUM>, <NUM> is one example of how to arrange a wide-angle pivot for the moveable jaw <NUM>. The moveable jaw <NUM> can then be implemented with very compact dimensions. In other words, it can be implemented, for example, without special elbows or lugs protruding from it, which could, for example, interfere with the operation of the work device <NUM> and/or visibility, or could also increase the weight or imbalance of the work device <NUM>.

On the other hand, the hydraulic actuator <NUM> can also be relatively short, to create a large movement for the moveable jaw <NUM>. The stroke of the operating element <NUM> of the hydraulic actuator <NUM> arranged to move can be, despite the large movement range of the jaw <NUM>, only <NUM> - <NUM>. The maximum opening of the grab <NUM>, i.e. the greatest distance between the points of the claws <NUM>, <NUM> of the jaws <NUM>, <NUM> when the moveable jaw <NUM> is in the extreme position and the grab <NUM> is thus open, is, for with the order of size of the work device <NUM> according to the example, <NUM> - <NUM>. The opening can vary according to the order of size.

The arm mechanism <NUM> and its pivots <NUM>, <NUM> are arranged in such a way that the farthest pivot <NUM> of the arm mechanism <NUM> relative to the hydraulic actuator <NUM> and, more especially to its operating element <NUM> arranged to move, can be arranged to move behind the rotation pivot <NUM> of the moveable jaw <NUM>, in the extreme position of the moveable jaw <NUM>. This extreme position is when the grab <NUM> is fully closed (<FIG>). Thus, the claws <NUM> of the moveable jaw <NUM> are arranged to intermesh with the claws <NUM> of the fixed jaw <NUM>. The grab <NUM> can then be completely closed as the jaws <NUM>, <NUM> intermesh with each other. In this situation, the rotation pivot <NUM> of the moveable jaw <NUM> is between the hydraulic actuator <NUM> and the pivot <NUM>, arranged in connection with the moveable jaw <NUM>, which belongs to the arm mechanism <NUM>. <FIG>, for example, shows this situation. This is only one example of a way to define both the implementation of the arm mechanism <NUM> and also the setup of the wide-angle pivot <NUM> and movement in connection with the invention.

According to the invention, the arm mechanism <NUM> includes a jaw arm <NUM>, including two pivots <NUM>, <NUM>. The jaw arm <NUM> is arranged to rotate the moveable jaw <NUM>, with the linear movement of the moving operating element <NUM> of the hydraulic actuator <NUM>. According to the embodiment described, the jaw arm <NUM> can be formed of two adjacent arms connected to the pivot points. At its first end, the jaw arm <NUM> is pivoted to the hydraulic actuator <NUM> and now most particularly to the loop fitted to the end of its moving operating element <NUM>. At the other, opposite end, the jaw arm <NUM> is pivoted to the moveable jaw <NUM>. In the jaw <NUM> there is an opening <NUM> in its base part <NUM> (or in the quick-release connector <NUM> of the jaw <NUM>) for a pivot <NUM>, implemented once again an adjacent pair of openings. The pivot <NUM> is in the base part <NUM> of the jaw <NUM> (or in the quick connector <NUM> of the jaw <NUM>), at a distance from the rotation pivot <NUM> of the jaw <NUM>. If either a pushing or pulling movement is directed, by the moving operating element <NUM> of the hydraulic actuator <NUM>, through the jaw arm <NUM> to the pivot point <NUM> of the jaw arm <NUM> fitted to the base part <NUM>, the jaw <NUM> is forced to rotate relative to its rotation pivot <NUM>, thus either opening or closing the grab <NUM>.

According to one embodiment, the jaw arm <NUM> is arranged to be curved, to form a turning rod to the moveable jaw <NUM>. The hydraulic actuator <NUM> can then be located mainly horizontally in the body <NUM> of the work machine <NUM> and nevertheless achieve a very wide motion range for the moving jaw <NUM>, especially for closing the grab <NUM>, i.e. for bringing it out of the way, intermeshed by the fixed jaw <NUM>. In addition, the hydraulic actuator <NUM> is then shielded inside the casing structure <NUM>. The jaw arm <NUM> then rotates behind the rotation pivot <NUM> of the moving jaw <NUM> as the grab <NUM> closes. In other words, the rotation pivot <NUM> is then located on the concave side of the curved jaw arm <NUM>. This rotation is very clearly seen, for example, in <FIG>.

In the embodiment described, the arm mechanism <NUM> also includes a rotatable lever arm <NUM>. The lever arm <NUM> is fitted between the jaw arm <NUM> and the body <NUM>. The lever arm <NUM> is now used to ensure that the movement of the jaw arm <NUM> created by the operating element <NUM> of the hydraulic actuator <NUM> arranged to move, is arranged to be converted into a rotational movement of the moveable jaw <NUM>. Thus the lever arm <NUM> is arranged to act on the jaw arm <NUM>. The lever arm <NUM> then controls the movement of the jaw arm <NUM> in such a way that the jaw arm <NUM> is not able to rotate relative to the jaw <NUM> without the jaw <NUM> rotating at the same time. In other words, the lever arm <NUM> is used to ensure that the jaw arm <NUM> acts over the entire motion range as an element either pushing or pulling the jaw <NUM>. in other words, the linear movement created by the hydraulic actuator <NUM> is retained over the entire motion range of the jaw <NUM> up to the jaw <NUM>, and is transmitted to the jaw <NUM>. This happens, even though the pivot <NUM> of the jaw arm <NUM> rotates behind the rotation pivot <NUM> of the jaw <NUM> relative to the operating element <NUM> of the hydraulic actuator <NUM> (<FIG>).

The lever arm <NUM> also protects the actuator <NUM> in the wide-angle pivot setup <NUM>. Due to it, the motion of the operating element <NUM> of the actuator <NUM> is certain to be kept straight the whole time, despite the large rotation angle of the jaw <NUM>, and no torsion acts on it, in which case the operating device <NUM> would be strained or possibly even break.

The lever arm <NUM> is equipped with pivoting <NUM>, <NUM>, now fitted to the operating element <NUM> of the hydraulic actuator <NUM> arranged to move, and to the body <NUM>. The lever arm <NUM> can also be formed of two adjacent arms. There are pivot openings <NUM>, <NUM> for the pivoting <NUM>, <NUM>, in the ends of the lever arm <NUM>. The pivoting <NUM> to the moving operation element <NUM> of the hydraulic actuator <NUM> takes place by a pin <NUM> from a loop at its end. In the body <NUM> there can be, in turn, a pivot opening <NUM>, for example, arranged to a lug <NUM> for the pivoting <NUM> of the lever arm <NUM> to the body <NUM>, using a pin <NUM> (<FIG>, <FIG>, and <FIG>).

Because two of the pivots <NUM>, <NUM> of the arm mechanism <NUM> are fitted to the same pivot point, i.e. now to the end of the moving operating element <NUM> of the hydraulic actuator <NUM>, the pivots <NUM>, <NUM>, <NUM>, <NUM> belonging to the arm mechanism <NUM> can now also be said, in the case according to the embodiment described, to be fitted to the triangular geometry. The triangle is then formed between the pivots <NUM> (<NUM>), <NUM>, <NUM> of the arm mechanism <NUM>. According to another embodiment, the lever arm <NUM> can also be fitted to pivot to some point on the jaw arm <NUM>, instead of the operating element <NUM>. However, this leads to one additional pivot in the wide-angle pivot setup <NUM> according to the embodiment described.

According to one embodiment, the implementation of the arm mechanism <NUM>, particularly in the placing of the pivots <NUM>, <NUM>, can also be defined by straight distances D1, D2 from the point <NUM> of the moveable jaw <NUM> to the pivots <NUM>, <NUM> (<FIG>) fitted to the base part <NUM> at its opposite end. The distance D1 from the points <NUM> of the moveable jaw <NUM> to the pivot <NUM> fitted to the moveable jaw <NUM> for the jaw arm <NUM>, is greater than the corresponding distance D2 from the points <NUM> of the moveable jaw <NUM> to the rotation pivot <NUM> of the jaw <NUM>.

According to one embodiment, the width W1 of the moveable jaw <NUM> can be <NUM> - <NUM> % of the width W2 (<FIG>) of the fixed jaw <NUM>. Besides this improving the visibility of the grab <NUM>, the grab <NUM> is also made lighter. The wider fixed jaw <NUM> is very suitable, for example, for raking, stump lifting, and other soil-tilling work, in which the work device <NUM> is used without the moveable jaw <NUM>. This is also helped by the wide-angle movement of the moveable jaw <NUM>. Thanks to the invention, it can be turned well clear, even in both directions, when not needed. The moveable jaw <NUM>, which is narrower than the fixed jaw <NUM>, is also not so liable to be caught in obstacles, for example, in demolition work.

One way to implement the structure of the moveable jaw <NUM> is to connect its pointed <NUM> claws <NUM> from the side surfaces of the base <NUM> by plate flanges. In the moveable jaw <NUM>, there are two or more claws <NUM>, i.e. working widths, for example for gripping objects with the grab <NUM>. At the opposite end of the jaw <NUM> to the points <NUM>, there is now a tubular beam <NUM>. The roots <NUM> of the claws <NUM> and the sheet metal-flanges <NUM> now join to the tubular beam <NUM>. In the case of the lug-less base plate <NUM> of the moveable jaw <NUM>, equipped with pivots <NUM>, <NUM>, which is at the opposite end of the jaw <NUM> to the point <NUM> of the jaw <NUM>, the implementation can, according to one embodiment, be such that an integral sheet-metal work piece <NUM>, which is also called a quick connector <NUM> later in the description, in which the pivots of the moveable jaw <NUM> are fitted, i.e. the rotation pivot <NUM> of the moveable jaw <NUM> and the pivot <NUM> of the arm mechanism <NUM> in the side of the moveable jaw <NUM>, can be fitted to the base part <NUM>. Thanks to the lack of lugs, the curve radius of the arm mechanism <NUM> of the moveable jaw <NUM>, more particularly of the pivot <NUM> of its jaw arm <NUM>, can be at a maximum the width of its base part <NUM>.

More generally, the sheet-metal work piece <NUM> can also act as an adapter, and even more particularly as a quick connector <NUM> for the moveable jaw <NUM>, more generally for the moveable work element <NUM>'. <FIG> shows a first example of a quick connector <NUM> for the moveable work element <NUM>'. In the quick connector <NUM>, there are then attachment means <NUM>, such as, for example, a pin <NUM>. By means of the pin <NUM>, it can be attached through openings <NUM> to holes <NUM> fitted to the attachment lugs <NUM> of the movable jaw <NUM>. In addition, the quick connector <NUM> can also include downwardly opening hooks <NUM>. The hooks <NUM> align and support in the jaw <NUM> the tubular beam <NUM> fitted to it. Further, in connection with an opening <NUM> arranged in the quick connector <NUM> for the rotation pivot <NUM> of the jaw <NUM>, there can be collars <NUM> protruding axially on both sides of the relevant pair of openings. There can be a pair of openings <NUM> in the quick connector <NUM> for the pivot <NUM>. In it too, there can be axially protruding collars <NUM>. Here the outer surfaces <NUM> of the collars <NUM> form an alignment surface <NUM> for the moveable jaw <NUM>. The under surfaces <NUM> of the points <NUM> in the lugs <NUM> of the moveable jaw <NUM> then settle against the outer surface <NUM> of the collars <NUM>.

In addition, in the moveable jaw <NUM> there can be, in the lugs <NUM> arranged as extensions of its middle-most claws <NUM>, now in their lower parts, channel-like claws <NUM>, of which the point of the one claw <NUM> appears in <FIG>. The collars <NUM> of the rotation pivot <NUM> of the jaw <NUM> are arranged to align with these claws <NUM>, when the moveable jaw <NUM> is attached to the quick connector <NUM> and thus to the work device <NUM>. The claws <NUM> then oppose the outer surface <NUM> of the collars <NUM>, which in this context can also be called the alignment surface <NUM>. Thus the claws <NUM> act as a kind of hanger <NUM>'. In other words, the hook-like formations <NUM>, <NUM> in the quick connector <NUM> and lugs <NUM> are opposite in these, when the jaw <NUM> is attached in the quick connector <NUM>. The collars <NUM> and hooks <NUM> align the holes <NUM> and <NUM> in the quick connector <NUM> and lugs <NUM> with each other when fitted the work element <NUM>' to the quick connector <NUM> and the attachment pin <NUM>, i.e. the attachment means <NUM> is then easily put into the holes <NUM>, <NUM> intended for it, and the work element <NUM>' is attached to the quick connector <NUM> and through it to the body <NUM> of the work device <NUM>. Thus, the outer surfaces <NUM> in the hooks <NUM> and collars <NUM> can be said to be alignment surfaces <NUM> to align the moveable jaw <NUM> with the quick connector <NUM> when attaching it to the work device <NUM>. Correspondingly, the quick connector <NUM> also includes an opening <NUM> for the attachment element <NUM>, by which the moveable jaw <NUM> is arranged to be attached to the quick connector <NUM>.

<FIG> shows the work device <NUM>, equipped with a quick connector <NUM> according to another embodiment, without the moveable jaw <NUM>. According to what is shown in <FIG>, the quick connector <NUM> can be, when changing the work element <NUM>' in it, fixed in the body <NUM> by a pin <NUM> in the rotation pivot <NUM> arranged in it, and by a pin <NUM> in the pivot <NUM> arranged for it in the jaw arm <NUM>. Using the quick connector <NUM> permits the moveable jaw <NUM>, for example, to be quickly exchanged for a stump-chopping blade or other work element, if so wished.

In another embodiment of the quick connector <NUM> shown in <FIG> and <FIG>, the locking of the jaw <NUM> to the quick connector <NUM> and thus to the work device <NUM> now happens with an operating device. The use of an operating device can be, for example, an option in the quick connector <NUM>. This may then include mechanical attachment according to the embodiment of <FIG> or, on the other hand, it may not.

In the embodiment shown, the attachment mechanism now includes two small hydraulic cylinders <NUM>, <NUM>. They are placed between the pivot plates <NUM> belonging to the quick connector <NUM>, being thus protected. There are now two hydraulic cylinders <NUM>, <NUM>, set in opposite directions to each other. There are attachment lugs <NUM> for them in the pivot plates <NUM>, from which they are attached to the quick connector <NUM> by one end. <FIG> shows only the option for such an operating device, i.e. in it there are only lugs <NUM> without cylinders and the jaw <NUM> is attached by a pin <NUM>. In <FIG> in turn this option is also realized, i.e. it includes the actual operating devices <NUM>, <NUM> in the lugs <NUM>. At the opposite end of the hydraulic cylinders <NUM>, <NUM> is an operating element arranged to move back and forwards. The operating element can now act as an attachment means <NUM> creating locking. Thus, it can act directly as a locking pin <NUM>, or indirectly act on a separate locking pin or mechanism.

Here, in the embodiment shown in <FIG> and <FIG>, there are separate sheet-metal pieces <NUM> fitted close to and between the pivot plates <NUM>. There is then a small gap between the sheet-metal pieces <NUM> and the pivot plates <NUM>. The gap is such that the attachment lugs <NUM> of the movable jaw <NUM> can be fitted inside it. Then there are also inner collars (not shown) oriented between the pivot plates <NUM>, in the opening <NUM> arranged for the pivot <NUM>, instead of the protruding collars <NUM> of <FIG>. The outer surface of the inner collars then acts for a similar purpose as in the embodiment of <FIG>, i.e. as an alignment surface <NUM> for the under surfaces <NUM> (<FIG>) in the points <NUM> of the lugs <NUM> of the jaw <NUM>.

The easy interchangeability of the work element permitted by the quick connector <NUM> acting as an adapter further increases the versatility of the work device <NUM>. Instead of detaching and attaching two larger pivots <NUM>, <NUM>, the quick connector <NUM> permits the changing of the work element <NUM>' with the detaching and replacement of only a single preferably smaller pin <NUM> relative to the pivots <NUM>, <NUM>. This accelerates changing one work element <NUM>' for another. In addition, the attachment pin <NUM> is in an open place, relative to the pivots <NUM>, <NUM>, for its detaching and attaching.

According to another embodiment, the pivots <NUM>, <NUM> of the moveable jaw <NUM> could also be directly in the lugs <NUM> formed as extensions of its middle claws <NUM>.

According to one embodiment, there can be a bulldozer blade <NUM> located on the rear side of the fixed jaw <NUM>, i.e. on the opposite end to the claws <NUM>. This can be used, for example, to level soil, i.e. the work device <NUM> can then also act as a drag. This property is useful, for example after stone lifting by the work device <NUM>. The bulldozer blade <NUM> can then be used to level the site by filling the pit created.

Above the hydraulic actuator <NUM> is a known double-acting liquid operated hydraulic cylinder, equipped with a single piston and piston rod. According to one embodiment, the hydraulic actuator <NUM> of the work device <NUM> can also be, for example, the variable force hydraulic cylinder formed by nesting operating elements, disclosed in the applicant's international patent application <CIT> or <CIT>. Using these, quick operation and, if necessary, also a great compressive force can be obtained for the grab <NUM> of the work device <NUM>.

<FIG> show yet another accessory for the work device <NUM> according to the invention. This is a bucket <NUM>. The bucket <NUM> can be permanently joined to the fixed jaw <NUM>. If the bucket <NUM> is threaded onto the claws <NUM> of the fixed jaw <NUM> by the lugs <NUM> fitted to it, like a glove on a hand, the bucket <NUM> is picked up by the work device <NUM> and remains in place by closing the grab <NUM>, i.e. by pressing the moveable jaw <NUM> onto the bucket <NUM>. For gripping, there are counter-pieces <NUM> in the bucket <NUM> for the moveable jaw <NUM>. In other words, the moveable jaw <NUM> then presses the bucket <NUM> in place and also holds it in the grip of the grab <NUM>, closed in contact with the fixed jaw <NUM>. This too is aided by the wide-angle pivot setup <NUM>. Thanks to it most of the bucket <NUM> remains from its lower part completely open and thus available for working. The bucket <NUM> can also be equipped, for example, with locks. Then, if needed, the bucket <NUM> can also remain in place, even if the moveable jaw <NUM> is used for normal work, i.e. even if it is not holding the bucket <NUM> in place. The moveable jaw <NUM> too can be equipped on the "glove principle", i.e. by a bucket that can be closed on the jaw <NUM> and/or an exchangeable bucket, which can be, for example, detachably attached to the quick connector <NUM>.

The work device <NUM> according to the invention is very versatile. Thus in connection with the invention one can speak of a multi-purpose grab. Its application is not limited purely to gripping an object with jaws <NUM>, <NUM> arranged to form a grab <NUM>, instead it can be used to perform several other operations too. Examples are stump, stone, and root-lifting and raking, collecting material either with the grab <NUM> or then even with only a fixed jaw <NUM> (e.g., energy timber, stumps, branches, and stones) and soil tilling, and demolishing buildings. This means that there is no need to change tools <NUM> in a work machine, such as, for example, an excavator, between operations, instead all operations can be performed effectively and with high quality on one and the same run. Though attaching tools is nowadays taken care of with various quick-connection solutions, their changing inevitably takes time, for example, on extensive work sites, at least through the driving needed for changing tools, and this is lost from productive work. In addition, owing to the invention there is no need to procure tools for several different tasks. One can operate using a single quick-connection solution between the boom end and the tool <NUM>.

Claim 1:
A work device, which includes
- a body (<NUM>) equipped with an attachment arrangement (<NUM>) for arranging the work device (<NUM>) at an end of a set of booms of a work machine,
- a pair of jaws (<NUM>) fitted to the body (<NUM>), which includes two jaws (<NUM>, <NUM>) arranged to form a grab (<NUM>), of which the first of the jaws (<NUM>) of the pair of jaws (<NUM>) forming the said grab (<NUM>) is fitted permanently to the body (<NUM>) and the second of the said jaws (<NUM>) is pivoted rotatably and separately from the attachment arrangement (<NUM>) to the body (<NUM>) in order to open and close the said grab (<NUM>),
- claws (<NUM>, <NUM>) fitted to the jaws (<NUM>, <NUM>) in which the claws (<NUM>) of the moveable jaw (<NUM>) are arranged to intermesh with the claws (<NUM>) of the fixed jaw (<NUM>) for bringing the movable jaw (<NUM>) out of way of the fixed jaw (<NUM>),
- a hydraulic actuator (<NUM>) attached by one end (<NUM>) to the body (<NUM>) of the work device (<NUM>) and equipped with a moving operating element (<NUM>), which is arranged to act on the moveable jaw (<NUM>) in order to open and close the grab (<NUM>),
- a wide-angle pivot setup (<NUM>) arranged to the work device (<NUM>) between the moving operating element (<NUM>) of the hydraulic actuator (<NUM>) and the moveable jaw (<NUM>) in order to open and close the grab (<NUM>) by using only the movable jaw (<NUM>), which wide-angle pivot setup (<NUM>) is arranged to include
- an arm mechanism (<NUM>) equipped with two pivots (<NUM>, <NUM>) fitted on a jaw arm (<NUM>), by which is arranged to rotate the moveable jaw (<NUM>) by a linear movement of the moving operating element (<NUM>) of the hydraulic actuator (<NUM>),
- a rotatable lever arm (<NUM>) arranged between the jaw arm (<NUM>) and a pivoting (<NUM>) arranged for that to the body (<NUM>) to convert the movement of the moveable operating element (<NUM>) of the hydraulic actuator (<NUM>) into a rotational movement of the moveable jaw (<NUM>),
and by which a rotation angle of the movement created for the moveable jaw (<NUM>) by the said wide-angle pivot setup (<NUM>) has a magnitude of more than <NUM>°.