Patent Publication Number: US-4057192-A

Title: Tree harvesting machine

Description:
FIELD OF THE INVENTION 
     This invention relates to wood chipping machinery for use in the forest products industry to reduce whole trees and parts thereof to wood chips, and more particularly to certain useful and novel improvements in such machinery. Prior art patents of which applicant is aware include the following U.S. pat. Nos. 
     
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2,392,958           2,936,008                                             
2,594,583           3,173,618                                             
2,663,506           3,346,027                                             
2,679,873           3,661,333                                             
2,848,029           3,817,027                                             
                    3,861,602                                             
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     BACKGROUND OF THE INVENTION 
     Machinery of this character has been provided in the past and attention is particularly directed to applicant&#39;s assignees U.S. Pat. No. 3,661,333. The present application is directed to certain new and useful improvements which render such machines more economical to produce, and improve it in certain important respects. 
     Machinery in accordance with the patent mentioned, which I hereby incorporate by reference, has been well accepted by the forest products industry and presently is in wide use in the United States of America to reduce entire trees of various varieties to wood fiber chips which can be readily processed to make a large variety of products. Such machinery is proving extremely valuable to harvest trees in a manner to harvest large tracts of land while leaving sufficient trees in place for future harvesting. 
     One of the prime objects of the present invention is to provide a new chipper disc of unique configuration which offers a considerable number of advantages over the conventional circular chipper disc in prior usage. For example, a new disc, which has a knife mounting part of generally triangular configuration is considerably lighter in weight than conventional discs, and this enables it to be more easily transported, and reduces clutch problems by lessening the starting load. Furthermore, the new disc of unique design makes a quicker r.p.m. recover and there is a considerable reduction in rim stress. As a result, the new chipper disc will chip faster and more efficiently. 
     Still another object of the present invention is to provide a tree chipping machine of the character described wherein the chipper disc assembly includes chip collecting housings which travel with the chipper disc and avoid the tremendous wear problems which have occurred in prior art machines, wherein the chips travel through the chipper disc, once cut, and impinge against the rear stationary wall of the chipper disc housing. The present chip collecting housings are of increasing girth or volume to avoid any wedging of masses of chips in the housing, and the apparatus is capable of operation at slower speeds than formerly without deleterious effect. 
     Still a further object of the invention is to provide forest products harvesting machinery of the character mentioned wherein mechanism is provided for partially revolving trees with forked trunks being fed to the chipper disc opening to permit the opening to accommodate trees having crotches, which would in unrotated position, not be able to pass through the chipper housing opening. 
     Still another object of the invention is to significantly improve the machine of the prior art, while at the same time making such machines more economical to manufacture and acquire, without in any way reducing effectiveness or reliability. 
     Other objects and advantages of the present invention will become apparent to those of ordinary skill in the art as the description thereof proceeds. 
     SUMMARY OF THE INVENTION 
     Machinery for reducing whole trees and parts thereof to wood chips wherein a live feed bed, a vertically adjustable, generally horizontal, powered roller positioned thereabove, and generally vertical powered side roll means feed a tree to a knived chipper disc. One improvement is concerned with the provision of chip collecting and releasing housings of outwardly increasing girth on the rear face of the disc assembly to rotate therewith. Other improvements are concerned with the provision of tree rotating means at the mouth of the chipper opening, and the construction of the chipper disc and live feed bed. 
    
    
     The present invention may be more readily described by reference to the accompanying drawings wherein: 
     FIG. 1 is a top plan view of the machine, part of the chipping disc assembly being broken away as shown for purposes of clarity; 
     FIG. 2 is a front elevational view thereof, taken from the charge or rear end of the machine, the chain lines indicating the feed opening in the front of the chipper housing; 
     FIG. 3 is a side elevational view of the machine with portions partly broken away to illustrate the construction thereof, the chain lines illustrating a raised position of the top roll; 
     FIG. 4 is a transverse sectional view through the chipper disc housing, showing the face of the chipper disc and illustrating the construction thereof; 
     FIG. 5 is a fragmentary, sectional view taken on the line 5--5 of FIG. 4; 
     FIG. 6 is a fragmentary, sectional view taken on the line 6--6 of FIG. 4; and 
     FIG. 7 is a perspective view illustrating the configuration of one of the chip collecting housings which secure to the rear of the chipper disc assembly. 
    
    
     Referring now more particularly to the accompanying drawings and in the first instance to FIGS. 1, 2 and 3, my machine is shown as comprising a frame, generally designated F, which may include the bed of a trailer and be mounted on wheels in the manner of the machine is disclosed in U.S. Pat. No. 3,661,333. The frame includes side bed portions 10 and 11, defined by a recess 12 which is open to accommodate a &#34;live&#34; conveyor bed, generally designated 13. The &#34;live&#34; bed comprises an endless conveyor, having an upper run which, as FIG. 3 indicates, proceeds at the level of the bed portions 10 and 11 along a guide 13a and is driven in the direction x (see FIG. 3), to deliver trees being processed toward a chipping disc housing, generally designated C (see FIG. 1) which is angularly disposed relative to conveyor 13. 
     Provided to assist the &#34;live&#34; bed 13 in moving a tree T being processed to the chipping assembly C, are a vertically movable, horizontal roll, generally designated 14, which is crosswisely disposed to conveyor 13, and a pair of vertically disposed side rolls generally designated 15 and 16. The roll members 14, 15, and 16, which later will be described in more detail, are driven at coordinated tree advancing speeds in correlation with the conveyor 13, in the direction of arrows a, b and c, respectively. 
     The &#34;live&#34; bed conveyor 13 is shown as comprising an endless member trained around front and rear sprockets 17 and 18, respectively, which are fixed on shafts 19, supported in the usual bearing housed in frame parts 10 and 11. One of the shafts 19 is driven by a conventional rotary hydraulic motor 20. 
     The conveyor 13 comprises a series of connected elongate plates 21, each having central sprocket teeth receiving openings 22 (FIGS. 1 and 2) provided in the leading edges thereof. Pins 23 welded to the leading ends of each plate 21, and journaling sleeves 24 and 26 welded at the trailing upturned ends 21a of each plate 21, provide a pivotal connection between the conveyor plates 21. The upturned edges 21a&#39; tend to bite into trees being carried on the conveyor 13 as the trees are forced down on conveyor 13 by the pressure of top roll 14, while still permitting trees to readily move laterally to centered position. 
     Provided on the frame portions 10 and 11 are upstanding support and tree guide posts 27 and 28 and pivotally mounted on pins 29 on the posts 27 and 28 is a top roll support frame, generally designated 30. The frame 30 includes side plates 31 connected by a top wall 32 which supports dependent plates 33, on which are mounted bearings 34 for the drive shaft 35 of top roll 14. A hydraulic cylinder 36, pivotally connected at 37 with a support arm 38 provided on frame F, has a piston rod 39 pivotally connected at 39a with one of the side plates 31 and is operable to raise and lower the roll support assembly 30 about pivot pin 29 to raise and lower horizontal roll 14 between the lowermost solid line position shown in FIG. 3, and the uppermost raised position shown in chain lines in FIG. 3 at 14&#39;. 
     The shaft 35, which is fixed to the roll 14 at 35b may be powered by a rotary hydraulic motor 40, via a drive chain 40a and sprockets 40b and 40c on the output shaft of motor 40 and shaft 35, respectively. As in U.S. Pat. No. 3,661,333, the drum 14a of the roll 14 is provided with spiral vanes 14b at its ends to tend to move a tree being conveyed laterally centrally on conveyor 13, and with circumferentially spaced bars 41 providing rows of tree surface engaging teeth 41a. Converging vertical side wall guides 42, which are curved at their lower ends as at 42a, extend forwardly from posts 27 and 28 for a distance and vertical side guides 43 and 44 are also provided to tend to confine the branches and limbs of the tree moving forwardly toward the chipper housing C. 
     The rear wall 31a of the roll mount structure 30 is provided with a series of projecting teeth 31b for the purpose of providing a grip or purchase on the tree when the loader arms are loading a tree T onto conveyor 13. The teeth 13b will bite into the end of a tree being loaded trunk foremost and aid the crane operator in his task of moving the tree into operative relationship with the feeding devices. 
     The roll 16, which has a drum 16a with a series of circumferentially spaced bars 45 which are serrated as at 46 to provide tree engaging and grasping teeth, is mounted for rotation about a vertical axis on a shaft 47, which may be suitably journaled via bearings provided on frame supports 48 and 49. The roll 16 is provided to project inboard of the end of roll 14 adjacent one side of the mouth of the opening O (FIG. 2) in the rear wall 50 of the angularly disposed chipper housing C. A rotary hydraulic motor 52 may be provided for driving the shaft 47 via a chain 47a trained around sprockets 53 and 54 on the motor 52 output shaft and on the shaft 47, respectively. At the opposite side of the machine, and adjacent to the horizontal roll 14, vertically disposed roll 15 is mounted to project laterally inboard of the end of roll 14 for rotation about a vertically disposed shaft 55. Shaft 55 is journaled by suitable bearings provided on frame F and is also driven by a suitable hydraulic motor 56 connected to the lower end of shaft 55 in any suitable manner. The roll 15 includes a part drum 57, which mounts helical vanes 58 extending upwardly about half the height of drum 57 for a purpose which later will be described in detail. The upper portion of drum 57 mounts circumferentially spaced vertical bars 59 which are serrated to form tree engaging teeth as at 60. 
     The chipper housing C includes, in addition to the rear wall 50, top wall 50a, angular side walls 50b and 50c, and a curvilinear lower wall or belly-band 50d extending to a chute 61 out which the chips cut are expressed. There is in addition, a forward wall 62, and a lower housing portion 63. The chipper housing is provided with a drive shaft 64, preferably driven via a Diesel engine in the manner described in the aforementioned patent in a suitable manner. Mounted on shaft 64, on the front face of an enlarged hub part 64a which projects rearwardly through wall 50, is a generally triangular-shaped knife mounting disc part generally designated 65 having a series of circumferentially spaced openings 65a provided therein. In the present instance, three such openings are shown and the chipper depicted is a three-blade chipper. It should be understood, however, that a fewer or greater number of knives may be provided to fit the particular operation to be performed. 
     The generally triangular-shaped knife mounting part 65 is relatively thick and heavy, compared with circular disc wear segments 66 which are secured to it by way of bolt member 67. Thus, while the composite disc is circular in character, it is made up of the relatively heavy knive mounting part 65 and much lighter circular segments 66, which include an outer circular edge 66a, an inner circular edge 66b, and side edges 66c, which adjoin the knife openings 65a. When two or four knives 72 are to be used, the knife mounting part 65 is square rather than triangular and four 90° wear plates 66 are used instead of three. 
     As FIG. 5 particularly indicates, each knife opening 65a is flared at its front end as at 65b, adjacent a chip collecting housing 69 which secures to the rear face of disc part 65. The housings 69 which are open at both ends include flanges 70 and 71 with opening 70a and 71a which permit them to be readily bolted to the disc part 65. It is important to understand that the generally U-shaped housings 69 are of constantly increasing girth, insofar as diverging side walls 69a are concerned, from the inner end thereof disposed adjacent to shaft 64 to the outer end thereof which extends slightly beyond the periphery or perimeter of segments 66 and disc part 65. 
     The usual chipper blade knives 72 extend rearwardly of the wear plates 66 into alignment with the openings 65a, as shown particularly in FIG. 5, and may be mounted in knife holders 72b secured to the triangular disc part 65 by way of bolts 73. It is to be understood that a knife blade 72, having a cutting edges 72a, is provided to project into alignment with each of the openings 65a and that rotation of the shaft 64 and composite disc assembly which it carries, is in the direction indicated by the arrow d in FIG. 4. Provided to cooperate with the knives 72, is a stationary anvil 74, which has a vertical edge 74a. A support wall 75 is provided as shown in FIG. 1, to mount the anvil 74 in operative position. 
     The hydraulic system employed for synchronously driving chain 13 and rolls 14, 15, and 16 forwardly or reversely may be the same as shown in U.S. pat. No. 3,661,333. 
     In operation, whole trees T, including the attached limbs and branches, are placed trunk foremost on the conveyor 13 by a loading crane associated with the machine, which I have not shown in the present drawings. The trees are, of course, extremely heavy and the butt ends of the trunk tend to swing in a horizontal plane as they approach the space between upright posts 27 and 28. The provision of the teeth 31b aid the crane operator in placing the butt of the tree in proper position generally centrally on conveyor 13. When the butt end of the tree hits teeth 31b, the teeth 31b tend to dig into the butt end of the tree and the butt does not simply slide along the back wall 31a. The operator can guide the butt end of a tree, which generally is being lifted from a side position relative to the machine and is skewed thereto, into a generally central position on the teeth 31b and then with teeth 31b penetrating the butt end, the skewed tree can be swung in a horizontal plane about the teeth 31b as a pivot into a position of longitudinal alignment with conveyor 13. 
     The butt end of the tree T enters the space between posts 27 and 28 and engages and pushes the roller 14 upwardly against the bias of cylinder 36. At this time, the conveyor 13 is moving the tree T in the direction x, and, as the roller 14 rides up over the end of the butt of the trunk, it (because of its rotation in the direction a) also tends to move the tree T forwardly. Thereafter, the roller 15 engages the trunk, or branches growing from the trunk, and tends, because of its rotation in the direction b, to also move the tree toward the chipper opening O. Finally, the side roll 16, because of its rotation in the direction c, also engages the tree or its branches and assists in moving it into the chipper opening O in a continuous manner. 
     As the tree T is fed forwardly, the rotation of chipper disc 65 is such as to continuously take a cut of, for example, 7/8th inch off the butt end of the tree with each pass of a chipper knife 72. The layer removed immediately breaks into chips which are accelerated from zero speed to a speed which might typically approach 12,000 feet per minutes, which is a typical knife speed. The chips move at this accelerating speed through the opening 65a and into the housing 69. Where, in former machines, they impinged against the stationary back wall of the chipper housing and there was considerable wear of the chipper housing back plate as a result, the wear factor is greatly reduced because housings 69 travel with the disc part 65. Moreover, because the housings 69 are of increasing girth, chips do not tend to bridge in housings 69 and instead are hurled as a mass spout 61 at the time each housing 69 approaches alignment with spout 61. The chips, in other words, gather or collect in the housings 69, and at the time the reach the position of alignment with spout 61, they are hurled out the spout 61 at an extremely high rate of speed. Spout 61, of course, connects with a spout extension which may feed the chips into a railroad car, truck, or the like. Because the chips cut with each pass are hurled as a collected mass, there is no problem with breakage due to contact with fan blades, or the like, as in some prior machines. In the present instance, the centrifugal force of the rapidly rotating disc assembly is utilized to hurl the mass and, because of the constant growth or taper of the walls 69a of housings 69 in an outward direction, no wedging of the chips occurs in the housing. Typical thicknesses of wear plates 66 and disc part 65 are 3/4 of an inch and 4 inches respectively. 
     The chain 13 centers on the chipper opening O and as previously, vanes 146 tend to laterally center the material being fed toward the chipper housing C. Particularly when the upper portion of the tree is all that remains and mainly limbs and branches are being fed, the vanes 146 are valuable in maintaining the remaining portions of the tree centrally disposed as they are fed toward the chipper opening O. The powered serrated teeth 46 and 60 are also particularly valuable because they engage the limbs and branches and move them forwardly, the teeth providing purchase and gripping surfaces which a smooth roll simply would not do. 
     If a tree with a forked trunk is moving forwardly on the live bed 13, and one of the forked portions of the trunk engages the spiral vane 58 on roll 15, the vane 58 will tend to lift the forked portion and rotate the tree T about its axis just sufficiently so that it fits diagonally through the opening O with the greatest width of the tree substantially aligned with the longest cross dimension of opening O. 
     The unique chain construction utilized in the live bed 13 has a number of advantages for the type of work contemplated. The large surface pads or plates 21, for instance provide a large contact surface and further provide enough sharp edge surface to do a very good job of advancing the tree. The chain is hard to damage with the loader grapple, and there are no fatigue loaded pins as with some prior constructions. 
     It is to be understood that the drawings and descriptive matter are in all cases to be interpreted as merely illustrative of the principles of the invention, rather than as limiting the same in any way, since it is contemplated that various changes may be made in various elements to achieve like results without departing from the spirit of the invention or the scope of the appended claims.