APPARATUS FOR FELLING TREES

Abstract: An apparatus for felling trees comprises a frame (18), at least one movable gripping member (19) for gripping onto the trunk of the tree, at least one member (49) for cutting the tree trunk and at least one movable support member (33), which, by means of at least one power member (45), is applicable against the ground for providing a force actuating the tree trunk in a desired felling direction. The support member (33) is pivotally arranged on the gripping member (19).

Description: Apparatus for felling trees. FIELD OF THE INVENTION AND PRIOR ART This invention relates to an apparatus for felling trees, comprising a frame having at least one gripping member movably connected thereto for gripping the trunk of the tree, at least one member for cutting the tree trunk and at least one support member pivotally movable in the apparatus by means of a power member, said support member being designed to take support against the ground for the purpose of providing a force actuating the tree trunk in a desired felling direction- Such an apparatus is known by the Soviet patent 620 245 and its support member is pivotally journalled in the frame of the apparatus. Although this known apparatus is highly preferable through the possibility to provide a force for breaking down a tree without accordingly such force need to be exerted via the crane device or other carrying device carrying the apparatus, the known apparat is none the less associated with certain draw backs. As mentioned above the support member is journalled in the frame of the apparatus, which causes that the contact of the support member against the ground to be located considerably ahead of the tree trunk since the frame of the apparatus must be so designed that it does not inter- fer with the function of the pivotally movable grabbing members to grip the trunk of tree. A problem with apparatuses of this described type is, independently of whether they have a support member of the described type or not, that a tendency to pinching of the cutting member may arise during the execution of the cutting. This is especially serious in the case wher a saw sword, in general pivotally mounted, is used as a cutting member. In known apparatuses without support members the forces, which are actuating the tree trunk in a desired felling direction, are exerted by means of the crane device which carries the apparatus. By the loca tion and design of the support member according to the Soviet patent specification the apparatus is actuated by forces defining the felling direction in essentially the same way as when these forces are exerted via the crane device and thus similar tendencies of pinching the cutting member are existing. BRIEF DESCRIPTION OF THE INVENTION The object of the present invention is to further" deve- lope the apparatus defined in the introduction and to create possibilities to reduce the tendency of pinching of the cutting member. This object is obtained according to the invention in that the support member is arranged on the gripping member and in that the pivot bearing of the support member rela- tive the gripping member is displaced from the connection of the gripping member to the frame in a direction towards the outer end of the gripping member. This enables the support member to be located so that not only a force actuating the tree trunk in a desired felling direction can be exerted by means of the same support member, but also forces which tend to actuate a tree trunk upwardly during widening of the cut in the tree trunk also at the part of the tree trunk facing in the desired felling direction. It is preferable that the pivot bearing of the support member relative to the .gripping member is located proximat to its outer end, which means that the pivot bearing of the support member will be located in the area of the part of the tree trunk facing in the felling direction or, viewed in the felling direction, displaced beyond this part, when the apparatus is applied in felling positi relative to a standing tree. According to a particularly preferred embodiment of the invention at least one pressing member designed for applic tion against the tree trunk for exerting the felling force OMPI is arranged on the gripping member and movably designed relative to this. It is preferred that the power member for manoeuvring the support member, acts between the supp member and the pressing member so that the forces actuati the tree trunk in the felling direction need not be exert on the tree trunk via the gripping members. BRIEF DESCRIPTION OF DRAWINGS Referring to the appended drawings, below follows a close description of embodiments of the invention, which are cited as examples. In the drawings: Fig ' 1 is a side view of the apparatus according to the invention; fig 2 is a view of the apparatus from above; fig 3 is a view of the apparatus seen along the line 3-3 in fig 1 ; fig 4 is a view of the apparatus from above in another position than in fig 2; fig 5 is a view along the line 5-5 in fig 4; fig 6 is a side view of the apparatus during felling of a tree; fi g 7 is a side view of an alternative embodiment; fig 8 is a view from above of the apparatus according to fig 7; fig 9 is a view along the line 9-9 in fig 7; fig 10 is a partly cut view of the apparatus during felli of a tree; fig 11 is a view along the line 11-11 in fig 10; fig 12 is a view along the line 12-12 in fig 10, and fig 13 is a diagrammatic side view of an alternative embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT In fig 1-6 an apparatus for felling trees is generally denoted with 1. The apparatus comprises a frame 2 and two arm like gripping members 3 for gripping onto a tree trunk. The gripping members 3 are pivotally movable towar and away from each other about parallel axes 4. The means for pivoting the gripping members are of conventional type and have therefore not been shown. The frame 2 of the apparatus is connected to the end of an arm 7 included in a crane device, via a so called rotat 6. The crane device is in a conventional way carried by a cross-country vehicle. The rotator 6 is so designed that the apparatus 1 is turnable about an essentially vertical axis by means of the rotator. The stator of the rotator 6 is via a hinge 8 with horizontal axis connected to the arm 7 while the rotor of the rotator, shown at 9, is connected to the frame 2 via a hinge 10 with hori¬ zontal axis. To pivot the apparatus about the hinge 10 between the position shown in fig 1 , in which the members 3 extend horizontally, and a position, in which the member extend essentially vertically, an assembly known per se can be used, which is not shown in the drawings for gainin clearness. Support members 11 are arranged on the gripping members 3. More precisely each of the gripping members 3 has a support member located on the bottom side thereof, said support member being pivotally arranged on the gripping member about a hinge 12 which forms a pivot axis 13 which extends essentially horizontally when the apparatus has its gripping arms 3 located horizontally to grip a tree trunk. Each of the support members 11 has its hinge 12 relative to the associated gripping members, located proxi mate to the free outer end of the gripping member, i.e. the end facing away from the frame 2. The support members 11 have the character of elongated arms ' extending from the area of the hinges 12 along the gripping members In a direction towards the frame 2 and are mutually connected in the area of the frame by means of a connection link 14, which is pivotally connected to the two support membe 11 about axes which are aligned with the axes 4 when the support members in accordance with fig 1 , 3 and 5 are pivoted inwardly towards the gripping members and the frame. Also the connection link 14 forms a support member for supporting against the ground. To pivot the ground support unit consisting of the member 11 and the link 14, about the hinges 12 a piston-cylinder mechanism 16 is arranged, one end of which is connected to an attachment on the link 14 and the other end of whic is connected to an attachment on the frame 2. As appears from fig 2 and 4 the gripping members are at their free ends provided with projections 17 (see fig 4) designed so that mutual overlapping may occur. As indi cated with the dashed lines in fig 5 the projection 17 of one of the gripping members may thereby be arranged to be pivoted in between portions of the projection 17 on the other gripping member. Moreover, the projections 17 can, as appears from fig 4, be brought to overlap portions of the gripping members 3 lying above the support members 11. It should be observed that since the axes 13 not always are parallel, some sort of displaceable movement between the support members 11 and the link 14 must be possible. The cutting member 5, which in fig 2 is indicated as a " saw with pivotally movable saw sword, is so mounted on the frame 2, by not shown carrying members, that the saw sword can cut off the tree trunk starting from the part proximate to the frame 2 and so that the part of the tree trunk remote from the frame 2, is the last to be cut. In using the apparatus illustrated in fig 1-6 one proceeds according to the following: Firstly the vehicle carrying the crane device 7 is placed in a suitable position rela- tive to the tree to be cut down, after which the apparatus 1 pivoted upwardly to the position according to fig 1 OMPI , /λ with its gripping members 3 horizontal, is moved towards the tree trunk by means of the crane device and is brought to embrace this tree trunk by means of the gripping member 3 (see fig 2 and 4). After this pressure fluid is supplied to the piston-cylinder mechanism 16 so that this tends to pivot the support members 11 and 14 about the hinges 12. A breaking actuation on the tree trunk is thereby arising in a direction away from the frame 2. Then the cutting saw 5 is brought to move so that the tree trunk is cut off from the left end of fig 6 in a direction towar the right end of fig 6. As the saw sword and the saw chain running around this saw sword is cutting off the tree trunk, the breaking actuation on the tree trunk means that the tree trunk gradually begins to lean in the felling direction until the same is totally cut off. During the whole cutting the gripping members 3 are held against the tree trunk. The saw sword is moving in a plane located under the grip members 3 (se fig 6). The grip of the gripping members 3 around the tree trunk can also be maintained after the tree trunk has fallen down, for the purpose of using the apparatus 1 , the gripping arms of which now extend vertically downwardly, as a convention gripping device for, as an example, pull the root portion of the tree trunk to a processing machine or the like. In that the arm like support members 11 follow the grip¬ ping members 3 in their pivoting movement towards and away from each other, the support members do not interfe with use of the apparatus as a conventional gripper. Also the apparatus according to fig 7-12 has a frame 18 and two gripping members 19 pivotally movable towards and away from each other about hinges 20. The apparatus is designed to be carried by an arm 21 about a hinge with a horizontal axis 22, said arm 21 being included in a crane device carried by a vehicle. A rotator 23 arranged between the arm 21 and the frame 18 enables rotating of the apparatus about an essentially vertical axis. The assembly is by means not shown rotatable about an horizont OMPI axis 24 so that the apparatus may be manoeuvred between the position according to fig 7, in which the gripping members 19 extend horizontally to be able to embrace a standing tree, and a position where the gripping members 19 extend downwardly and the apparatus can function as a conventional gripper. In this embodiment the hinges 20 (fig 12) of the gripping members are displaceable towards and away from each other along a guide generally denoted 25, which forms part of the frame 18 of the apparatus. The guide 25 may, as seen in fig 9, consist of two parall.elly arranged guide " beams 26, to which fastening ears 27 are fastened for connec¬ tion of the apparatus to the rotator 23. Moreover, the guide beams 26 are mutually connected by means of rigid end-pieces 28. As appears from for instance fig 12 the guide 25 and thereby also the guide beams 26 have a sligh V-shape. On each of the guide beams 26 two bushes 29 are displace- ably arranged. The bushes on the two- guide beams are mutually connected in pairs and they carry axle spindles between each other, which are surrounded by bushes connec to the gripping members 19 and which accordingly form the pivot axes 20 of the gripping members. In fig 9 fastening ears 13 are indicated, which are fastened at said bushes on the gripping members 19 and between which axel spindles 31 extend. A piston-cylinder mechanism 32 has its ends connected to said axle spindles 31. From the description above it appears that the gripping members 19 on one hand can be brought towards and away from each other by pivoting abouf ' the axes 20, and on the other hand can be brought towards and away from each other by allowing the hinge axes ' 20 carrying the bushes 29 to be displaced towards and away from each other along the guide beams 26. Simultaneous displacement of the axes 20 and pivoting of the gripping members may of course occur. Concerning the achievement.- of these possibilities of moving of the gripping members several variants are OMPI possible. It is thinkable to arrange a piston-cylinder mechanism as the one denoted 32, to manoeuvre the pivot movement of the gripping members 19 and to arrange a further piston-cylinder mechanism (not shown) to displace the bushes 29 and thereby the pivot axes 20 towards and away from each other along the guide beams 26. Concer¬ ning the remaining possibilities of manoeuvring it is referred to the applicant's Swedish patent application 8105907-3, which is particularly concentrated on this type of gripping device with combination of possibilities of pivoting and displacing. Also in this embodiment support members are arranged, more precisely one support member 33 for each of the grip¬ ping members 19. As appears most clearly in fig 10 and 11 the support members 33 are by means of hinges 34 pivotally arranged about axes 35, which are essentially horizontal when the apparatus is applied on the standing tree. The hinges 34 are with advantage located near the outermost end portions of the gripping members 19 while the support members have an arm like shape and extend from said hinges 34 in a direction towards the frame por¬ tion 18 of the apparatus. The support members are loca¬ ted on the bottom side of the gripping members 19 when the same are gripping onto a standing tree. As appears in fig 11 the support members 33 are mutually connected in the ends facing away from the hinges 34 by means of a guide 36, which also forms a support member for appli¬ cation against the ground. The guide 36 has a V-shape similar to the previously described guide 25 and the suppo members are hingedly connected to bushes 38 around hinge axes 37, said bushes 38 being displaceable along said guide. As appears most clearly in fig 8, the apparatus is pro¬ vided with a pressing member 39 designed for application against the tree trunk (see fig 10) to exert felling force thereon. The pressing member 39 has a slight V-shape and is also constituting a guide for bushes 40, which are displaceably movable towards and alon the ressin member. These bu hes are hin edl ' fastened (about axes 41) to arms 42, which by means of hinges 43 are hingedly connected to the gripping members 19 at their outer ends. The pivot axes 44 formed by the hinges 43 are essentially parallel to the pivot axes 35 of the support members 33. As appears in fig 9 and 10 piston-cylinder mechanisms 45 act between the support members 33 and the pressing member 39. More precisely these mechanisms 45 act between fasteners 46 arranged on the bushes 38 and fasteners 47 arranged on the bushes 40. It should now be understood that the support members 33 and the guide 36 as well as the pressing member/guide 39 and the arms 42 are lying essentially parallel to the plane of movement of the gripping members, when the mecha- nisms 45 are contracted according to fig 7 and 9. On ' pivoting the gripping members 19 towards and away from each other the support members 33 and the arms 42 will follow while pivoting about the hinges 37 and 41. In case the bushes 29 of the gripping members 19, said bushes carrying pivot axes 20, are displaced along the guide beams 26, the bushes 38 and 40 will also be brought to be displaced along their associated guides 36 and 39 during transfer of force via the support members 33 and the arms 42 respectively. It is now also obvious that an extension of the piston-cylinder mechanisms 45, com¬ pared to the position according to fig 7 and 9, will lead to a tendency of pivoting of the support members 33 with the associated guide 36 and bushes 38 about the hinges 34 in a direction away from the gripping members at the same time as the pressing member 39 and the associated bushes 40 and arms 42 receive a tendency of pivoting about the hinges 43 in a direction away from the gripping member More precisely the support members 33 and the pressing member 39 will be pivoted away from the gripping members in essentially opposite directions. Since the hinge axes 35 of the support members are not totally parallel in OMPI some pivot positions of the gripping members 19, pivo¬ ting of the support members will, in such adjustments of the gripping members, result in a certain displacement of the bushes along the guide 25. The same applies for the pressing member 39 and its bushes 40. The apparatus comprises a cutting member which may con¬ sist of a saw 48 with a pivotally movable sword 49 around which the saw chain is running. The cutting saw is mounted on a frame 18 Joy means of mounting means not shown. It is essential that the cutting saw is designed to cut a tree trunk by starting in the area of the frame 18 and so that the section of the tree trunk nearest the free ends of the gripping members are the last to be cut. As appears in fig 10 the saw sword 49 indicated with the dashed line, is pivotally movable in a plane under the gripping members but above the support members 33. While using the apparatus according to the invention the same is applied, by means of a crane device, so that the gripping members 19 with the mechanisms 45 contracted may be brought to embrace a standing tree in the proxi¬ mity of its root portion. After this the piston-cylinder mechanisms 45 are extended so that the support members 33 and 36 are laid against the ground by pivoting about the hinges 34 at the same time as the pressing member 39 by pivoting about the hinges 43 is laid against the side of the tree facing in the direction opposite the felling direction (see fig 10). Thereby one obtains that the forces breaking down the tree, not at all or just in a small degree will actuate the gripping members, the frame and the cutting member mounted thereon so that the risk for pinching or binding of the cutting member is essentially reduced. Instead the piston-cylinder mechanis 45 may transfer their forces, which are breaking down the tree trunk, directly onto the tree trunk with star- ting point from the support members 33 which are lying steady on the ground, since the piston-cylinder mecha¬ nisms 45 act directly between the support members 33 and the pressing member 39. / ■^-gϋ E OMPI In fig 13 an embodiment is illustrated which essentially corresponds to what has been described in connection with the figures 7-12. The only difference is that the hinges 35 and 43 on each gripping arm 19 in the embodiment accor ding to fig 13 have been connected to each other by means of a connection member 50, which enables the support memb 33 associated with said gripping member and the arm 42, and thereby also the pressing member 39, to be in a certa degree displaceably movable back and forth in a direction indicated by the arrow 51, i.e. in the direction perpen¬ dicular to a plane of moving of the gripping members. Springs 52 are with advantage arranged to maintain the state of equilibrium illustrated in fig 13. The connectio member 50 may preferably run in a recess 53 in the grippi member, which recess may be slightly hour-glass-shaped to allow transversal movement of the connection member 50 in the recess. It is obvious that the gripping member with associated support members 33 and arm 42 which is not shown in fig 13, are designed in a similar way as appears in fig 13 in connection with the gripping member shown therein. It is obvious that several modifications of the invention are possible within the scope of the spirit of this inven tion.

Claims: Claims 1. An apparatus for felling trees, comprising a frame (2, 18) having at least one gripping member (3, 19) movabl connected thereto for gripping the trunk of the tree, at least one member (5, 18) for cutting the tree trunk and at least one support member (11, 14, 33, 36) pivotally movable in the apparatus by means of a power member (16, 45), said support member being designed to take support against the ground for the purpose of providing a force actuating the trunk in a desired felling direction, c h a r a c t e r i z e d in that the support member ' is arranged on the gripping member (3, 19), and in that the pivot bearing (12, 34) of the support member relative to the gripping member is displaced from the connection (4, 20) of the gripping member to the frame in a direction towards the outer end of the gripping member. 2. An apparatus according to claim 1, c h a r a c t e¬ r i z e d in that the pivot bearing (12, 34) of the support member relative to the gripping member (3, 19) is located proximate to its outer end. 3. An apparatus according to claim 1 or 2, c h a r a c¬ t e r i z e d in that the support member (1T, 33) extends essentially along the entire extension of the gripping member, and in that the power member (16) is acting betwee the support member and the frame of the apparatus or the gripping member. 4. An apparatus according to any of claims 1-3, c h a r a c t e r i z e d in that the pivot bearing (12, 34) of the support member is located relative to the gripping member so that, viewed in the direction of felli the pivot bearing is located beyond the center of the tree trunk, when the apparatus is located in felling posi tion at a standing tree. OMPI 5. An apparatus according to any previous claim, c h a r a c t e r i z e d in that at least one pressing member (39) designed for application against the tree trunk for exerting a force for felling the same, is movab arranged on the gripping member. 6. An apparatus according to claim 5, c h a r a c t e¬ r i z e d in that the pressing member (39) is pivotally arranged on the gripping member so that the pressing mem¬ ber and the support member are pivotable in a direction away from each other. 7. An apparatus according to claim 5 or 6, c h a r a c¬ t e r i 'z e d in that the power member (45) for the contr of the support member (33) is acting between the support member and the pressing member. 8. An apparatus according to anyone of claims 5-7, c h a r a c t e r i z e d in that the support member (33, 36) and the pressing member (39, 42) are displace- ably movable relative tothe gripping member in a direction along a tree trunk held in the apparatus (fig 13). 9. An apparatus according to anyone of claims 5-8, c h a r a c t e r i z e d in that it comprises two gripping members (19) which are pivotally movable towards and away from each other and which each carries a support member (33) and an arm (42) carrying or presenting the pressing member, said support member and said arms being arranged to follow the gripping members in their move¬ ments towards and away from each other. OMPI . . WIPO

Inventors: ERIKSSON JAN, ERIKSSON, JAN
Applicants: ERIKSSON JAN, ERIKSSON, JAN
Application year: 1983
Main classification: A01G23
IPC codes: A01G23