Abstract:
The invention relates to an operating device for a tool, comprising a frame to be coupled to the boom of an excavator or the like. at least one tool connected to the frame as well as adjusting means for positioning said at least one tool relative to the boom. The object of the invention is to provide a device of the kind referred to in the introduction, which enables a more versatile use and which, as a result of an improved maneuverability of the tool, is capable of carrying out operations also at places that were previously considered to be difficult to reach. According to the invention, the device is to that end characterized in that the adjusting means also comprise a ball and socket joint, which pivotally connects said at least one tool to the frame.

Description:
CLAIM OF PRIORITY 
       [0001]    This application claims priority under 35 USC § 119 and 365 of commonly owned PCT Application No. PCT/NL2005/000695 filed Mar. 26, 2005. This application designated the United States and was published in the English language on Mar. 29, 2007 as WO 2007/035083 which is incorporated in its entirety by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The invention relates to an operating device for a tool, comprising a frame to be coupled to the boom of an excavator or the like, at least one tool connected to the frame as well as adjusting means for positioning said at least one tool relative to the boom. 
       DESCRIPTION OF RELATED ART 
       [0003]    Such a device is known, for example from Dutch patent application No. 95/00343. and it can be used for lopping and/or felling trees. The known devices are arranged for felling trees in one go, for example by clamping a gripper element coupled to the boom around the trunk and cutting off the trunk near the ground by means of a tool, for example in the form of a sawing unit. The tree is then lowered to the ground in a controlled manner and either carried off or mechanically processed into manageable parts on site. 
         [0004]    The extent to which the tool can be positioned with respect to the tree to be processed is quite limited with the device according to NL-95/00343, it fully depends on the maneuverability of the boom to which the tool is coupled. The generally robust construction of the boom as well as its dimensions and mass stand in the way of a flexible and precise positioning of the tool with respect to the tree that is to be felled, and consequently they are limiting factors as regards the usability of the devices that are currently known. 
         [0005]    U.S. Pat. No. 5,101,872 and U.S. Pat. No. 6,408,906, U.S. Pat. No. 3,720,246 and US 2003/0,015,251 disclose operating devices of the same kind as the operating device referred to in the introduction, which devices comprise adjusting means for positioning the tool relative to the boom. However, also in the case of the devices disclosed in the aforesaid patent specifications the number of degrees of freedom for positioning the tool is limited. 
       SUMMARY OF THE INVENTION 
       [0006]    The object of the invention is to overcome the aforesaid drawback and to provide a device of the kind referred to in the introduction, which enables a more versatile use and which, as a result of an improved maneuverability of the tool, is capable of carrying out operations also at places that were previously considered to be difficult to reach. According to the invention, the device is to that end characterized in that the adjusting means also comprise a ball and socket joint, which pivotally connects said at least one tool to the frame. 
         [0007]    This enables a more accurate positioning within a smaller positioning space of said at least one tool relative to the boom and consequently to the working position, for example a tree to be handled. Now said at least one tool can also carry out operations at locations which previously could not be reached by just maneuvering the boom. 
         [0008]    Said more accurate positioning within a smaller positioning space of the at least one tool makes it possible to fell a tree in stages (“branch by branch”) rather than in one go when felling a tree by means of the device according to the invention. This makes it possible to use the device in residential areas, for example, where it is not possible to fell a tree in one go in connection with the presence of obstacles (houses, lamp posts, cars, etc). 
         [0009]    The use of a ball and socket joint provides a certain degree of freedom, which makes it possible to position said at least one tool also at positions that are difficult to reach. 
         [0010]    In a specific embodiment, by means of which an adequate control and positioning of the tool with respect to the working position (the tree, for example) can be obtained, the adjusting means engage the frame on the one hand and said at least one tool on the other hand. 
         [0011]    In a functional embodiment, the adjusting means are embodied as hydraulically driven adjusting means, which can be driven more specifically by the hydraulic system of the excavator. This obviates the need for a separate driving line for driving the device according to the invention, which makes it possible to realize a simple and inexpensive construction of the device. 
         [0012]    In another embodiment, the adjusting means are embodied as electromechanically driven adjusting means. The adjusting means may comprise at least one spindle drive, more in particular at least three spindle drives, in that case. 
         [0013]    In another functional embodiment, on the other hand, the adjusting means comprise at least one, more in particular at least three, piston-cylinder combinations. 
         [0014]    In a functional embodiment, said at least one tool is mounted on a supporting plate that is connected to the ball and socket joint, with the adjusting means engaging the supporting plate. 
         [0015]    The supporting plate makes it possible on the one hand to accommodate several. different tools and on the other hand to make it easier to position said tools with respect to the boom. 
         [0016]    In another functional embodiment, the adjusting means engage a guide element that is movable with respect to the frame. More specifically, the ball and socket joint can be connected to the frame by means of an arm, with the guide element being movably provided round the arm. This enables the guide element to orient itself upon adjustment of the ball and socket joint by means of the piston-cylinder combinations, so that jamming of the device is prevented. 
         [0017]    In another functional embodiment, in which said at least one tool can be positioned with respect to the boom (and the tree to be felled), the ball and socket joint is connected to the frame by means of a telescopic extension element. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]    The particular features and advantages of the invention as well as other objects will become apparent from the following description taken in connection with the accompanying drawings in which: 
           [0019]      FIG. 1  shows a prior art device, which is coupled to the boom of the excavator; 
           [0020]      FIG. 2  shows a first embodiment of a device according to the invention; 
           [0021]      FIG. 3  shows detail views of the embodiment of a device as shown in  FIG. 2 ; 
           [0022]      FIG. 4  shows a detail view of another part of the device according to the invention; 
           [0023]      FIGS. 5   a  and  5   b  show detail views of another embodiment of a device according to the invention; 
           [0024]      FIG. 6  shows yet another embodiment of a device according to the invention; and 
           [0025]      FIG. 7  shows yet another embodiment of a device according to the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0026]    For a clear understanding, identical parts are indicated by the same numerals in the drawings. The invention will furthermore be explained by way of example on the basis of a device for felling trees. It will be understood, however, that the invention can also be used for other operations, such as digging trenches or mowing sloping surfaces (road banks, dikes) etc. 
         [0027]      FIG. 1  shows a device according to the invention for lopping or felling trees. The device  3  is coupled to a boom  2  of an excavator  1  and is built up of a frame to which one or more felling tools  5   a - 5   b ,  6 ,  7  are mounted. The tool  5   a - 5   b  is made up of clamping jaws that can be positioned round the trunk of a tree  8 . The tool  6  is a chainsaw unit, which can be driven through the trunk of the tree  8  by suitable driving means so as to cut it down. The tree  8  thus cut down, which is clamped between the clamping jaws  5   a - 5   b , can be placed in a horizontal position by means of the boom  2  for further processing. The tool  7  is a chainsaw unit by means of which the roots  8   a  of the tree  8  can be cut. 
         [0028]    A drawback of the device as shown in  FIG. 1 , which is disclosed in Dutch patent application NL-95/00343, is the limited extent to which the felling tool(s) can be positioned with respect to the tree  8  to be handled. More specifically, the positioning of the felling tools with respect to the tree  8  is fully dependent on the maneuverability of the boom  2  to which the device  3  is coupled. As  FIG. 1  clearly shows, the boom  2  is of generally robust construction, and the dimensions and the mass thereof make it difficult to achieve a flexible and precise positioning of the device  3  and the felling tools  5   a , 5   b , 6 , 7  connected thereto with respect to the tree that is to be felled. The usability of the prior art device that is shown in  FIG. 1  is limited, therefore. 
         [0029]      FIG. 2  shows a first embodiment of a device  3  according to the invention which enables a more versatile use and which is characterized by an improved maneuverability of the felling tools with respect to the tree  8  to be handled. According to the invention, the device  3  is provided with adjusting means  12   a - 12   b  for positioning the felling tool(s) with respect to the boom  2 . The ball joint head  11  is provided with a socket  11   a , in which the ball  10  can be received. 
         [0030]    More in particular, the device  3  comprises a ball and socket joint  10 , 11  which pivotally connects the felling tools  5   a , 5   b , 6  to the frame  4  of the device  3 . The ball and socket joint  10 , 11  provides an additional degree of freedom to be imposed on the various felling tools  5   a , 5   b , 6 , making it possible to position said tools also at places round the tree  8  that could previously only be reached with (great) difficulty. 
         [0031]    To enable a flexible, a three-dimensional positioning of the felling tools with respect to the frame  4  and the boom  2 , the adjusting means are arranged in such a manner that they engage the frame  4  on the one hand and the felling tools on the other hand. The adjusting means may be embodied as hydraulically driven adjusting means, which can be driven in particular by the hydraulic system of the excavator  1 . This obviates the need for a separate driving line for driving the device according to the invention, which leads to a simple and inexpensive construction. 
         [0032]    In the hydraulic embodiment, the adjusting means comprise at least one piston-cylinder combination  13   a , 14   a , but more specifically three piston-cylinder combinations  13   a - 14   a ,  13   b - 14   b ,  13   c - 14   c  ( 12   a - 12   c ), which latter piston-cylinder combination  13   c - 14   c  ( 12   c ) is not shown in  FIG. 2 . Using three different piston-cylinder combinations  12   a - 12   c  being symmetrically arranged around the ball and socket joint  10 , 11  and being connected to the frame  4  and to the felling tools  5   a , 5   b , 6 , any desired position with respect to the boom  2  can be imposed upon the felling tools. Extension or retraction of the various piston-cylinder combinations  12   a - 12   c  results in movement of the ball joint head  11  over the ball  10  and thus in a required positioning of the felling tools with respect to the frame  4  and the boom  2 . 
         [0033]    The ball joint head  11  is furthermore provided with a supporting plate  11   b , to which the various tools  5   a , 5   b , 6  can be mounted by means of connecting mechanisms that are known per se, whether or not via a drivable rotation unit  15 , by means of which the tools can be rotated with respect to the frame  3 . This provides an additional degree of movement, resulting in an enhanced usability of the device according to the invention. 
         [0034]    Preferably, the tools  5   a , 5   b , 6  are mounted to a supporting plate  15 , on which the adjusting means  12   a , 12   b , 12   c  engage. In the embodiment that is shown in  FIG. 3 , the ball joint head  11  is divided into two plate members  11   c , 11   d , which are provided with a socket-like recess  11   a , in which the ball  10  of the ball and socket joint  10 , 11  can be received. The two plate members  11   c , 11   d  are fixed together by means of a bolt-nut connection extending through corresponding openings  18   a , 18   b . The ball joint head  11  can be pivoted between two extreme positions A and B of the frame  4  with respect to the ball  10  by the adjusting means (not shown). 
         [0035]    Another embodiment is shown in  FIG. 4 , which discloses a telescopic extension element  20  which can be connected to the boom  2  on the one hand (indicated at  3 ) and to the frame  4  on the other hand (as indicated at  4  in  FIG. 4 ). The extension element  20  is preferably built up of several extension segments  21   a , 21   e , which can telescope relative to each other and which can be retracted and extended by means of oil hydraulics. To that end a hydraulic medium under pressure (for example oil) is introduced into the extension cylinder segments  21   a - 21   e  via the opening  22 . The extension element  20  may also be embodied as a multistage piston-cylinder combination. Numerals  23   a - 23   e  indicate filling nipples for supplying oil or grease for the purpose of lubricating the extension cylinder segments  21   a - 21   e  sliding or moving past one another. 
         [0036]    The hydraulically driven telescopic extension element  20  makes it possible to effect an extension of the working range of the device according to the invention, which further enhances the usability of the device. The range of movement of the various extension cylinder segments  21   a - 21   e  is limited by various stops  24   a - 24   e  (only stop  24   a  is shown in  FIG. 4 ), so as to limit the maximum amount of travel of the various extension cylinder segments. 
         [0037]    In one embodiment, the maximum load the device is capable of handling is lower when the extension cylinder is in its fully extended position. The maximum load the device is capable of handling is higher when the extension cylinder is in its fully retracted position. 
         [0038]    The detail views of  FIGS. 5   a  and  5   b  show two operating situations of another embodiment of the device according to the invention. In this embodiment the ball and socket joint  10 - 11  forms part of the extension cylinder  20 . The adjusting means  12   a - 12   b - 12   c , etc. engage the ball joint head  11 /the supporting plate  11   b  on the one hand and the extension segment  21   d  of the extension cylinder  20  on the other hand. This makes it possible to impose a random orientation with respect to the frame  3  on the ball joint head  11  and the supporting plate  11   b  (and the felling tools mounted thereon) via the adjusting means  12   a - 12   b —etc. in the extended position of the extension cylinder  20 . 
         [0039]    Upon retraction of the extension the cylinder segment  21   e  in the direction of the extension cylinder segments  21   b - 21   c - 21   d , the ball joint head  11  can be received in a recess that is present in the extension cylinder segment  21   d . The recess is indicated at  30  in  FIG. 5   b . Since the ball joint head  11  can only be received in one orientation in the recess  30  of the extension cylinder segment  21   d  upon retraction of the extension cylinder  20 , a functional locking or fixation of the ball and socket joint  10 - 11  is obtained. The ball and socket joint  10  and the frame element  4  are accommodated in a recess  31  formed in the extension cylinder segment  21   c  in that situation. 
         [0040]    As a result of said locking or fixation of the ball and socket joint  10 - 11  in the fully retracted position that is shown in  FIG. 5   b , the device is very suitable for handling heavy masses which, for safety reasons, cannot be maneuvered by means of the ball and socket joint  10 - 11 . 
         [0041]      FIG. 6  shows yet another embodiment of a device according to the invention, in which the extension cylinder  20  is connected to the frame  3  by means of a hinge mechanism  32 - 33   a - 33   b . The frame  3  can in turn be connected to the boom (not shown) of an excavator by connecting means  34  that are known per se. (Also refer to  FIG. 1 ). Since the extension cylinder  20  can be pivoted with respect to the frame  3  and the boom of the excavator by additional adjusting means  33   a - 33   b  (also in this case embodied as hydraulic piston-cylinder combinations or electromagnetically driven spindles), an additional degree of movement of the device according to the invention is obtained. 
         [0042]    In this way it is possible to maneuver the felling tools that are mounted on the supporting plate  11   b  to any desired position with respect to the frame  3  and the boom  2  of the excavator. Because of this feature the device according to the invention is more versatile than the devices that are known so far. 
         [0043]    It will be understood that the device according to the invention provides a more versatile device for felling trees, by means of which device the various felling tools can be oriented with even greater precision with respect to the tree. The device according to the invention makes it possible to lop or fell a tree  8  in parts, i.e., branch by branch, rather than in one go, as is done with the prior art device. 
         [0044]    Said possibility to fell a tree branch by branch renders the device according to the invention very suitable for use at locations at which it is not possible to fell the tree in one go in connection with the presence of obstacles. Think in this connection of residential areas where the presence of houses, lamp posts, cars, etc., seriously interferes with the maneuverability of the excavator  1  with the boom  2  and a device  3  according to the prior art. 
         [0045]      FIG. 7  shows another highly functional embodiment of the device according to the invention. The ball and socket joint  10  on which the supporting plate  11 - 11   b  is mounted, to which supporting plate a processing tool (not shown) can in turn be connected, can be adjusted with respect to the boom (not shown) by means of several piston-cylinder combinations  14   a - 13   a . The ball and socket joint  10  and the frame member  4  are of to that end provided with a connecting element  33 . which can be connected to, for example, a boom (not shown) by means of a connecting plate  33 ′. 
         [0046]    Several piston-cylinder combinations  13   a - 14   a  are provided for adjusting the ball and socket joint  10  and the tool with respect to the boom. The cylinder  14   a  is connected with its end  13   a  to the end plate  11   b , whilst the piston  13   a  is connected to the connecting element  30   b  that is mounted on a guide element  31 , which is slidably mounted on an arm  32 . It will be understood that several piston-cylinder combinations  13   a - 14   a  are used for adjusting the end plate  11   b  about the ball and socket joint  10  with respect to the arm  32  (and the boom (not shown)), because both the end plate  11   b  and the guide element  31  are provided with several connecting elements  30   a - 30   b.    
         [0047]    The guide element  31  is movable around the arm  32  so as to realize an adequate positioning of the end plate  11   b  about the ball and socket joint  10 - 11 . This makes it possible to adjust the various piston-cylinder combinations  13   a - 14   a  with respect to each other, enabling the guide element  31  to orient itself, so that jamming of the device according to the invention is prevented. 
         [0048]    Numerous alterations of the structure herein disclosed will suggest themselves to those skilled in the art. However, it is to be understood that the present disclosure relates to the preferred embodiment of the invention which is for purposes of illustration only and not to be construed as a limitation of the invention. All such modifications which do not depart from the spirit of the invention are intended to be included within the scope of the appended claims.