Patent Publication Number: US-2015082762-A1

Title: Tree Trimmer

Description:
FIELD OF THE INVENTION 
     This invention concerns equipment for trimming trees and shrubs using a tractor and especially the hydraulic mounting components for enabling the tractor to utilise ganged circular saws. 
     BACKGROUND OF THE INVENTION 
     While much trimming of trees near powerlines is done by trained staff raised by cherry picker platforms and using chainsaws, the larger scale of rural sites requires large circular saws. It is useful to be able to present the blade at a vertical, horizontal and  45  degree angles in order to impart a desired profile to an avenue of trees lining a road or a cluster of trees near powerlines. 
     SUMMARY OF THE INVENTION 
     The apparatus aspect of the invention provides a mount assembly for the hydraulic arm of a vehicle which is operable to manipulate an array of tree trimming cutters, the assembly comprising a hydraulic arm extension connectable at one end to the hydraulic arm and at the opposite end to a cutter arm via a coupling, the coupling allowing rotation about a vertical axis permitting side to side cutter arm sweeps and rotation about a first horizontal axis permitting the inclination of the cutters to the ground to be adjusted, the cutter arm being pivotally connected to the coupling at one end and pivotally connected to the array at the opposite end such that the array is rotatable about a second horizontal axis executing a wrist like action and fluid operated means to actuate the assembly. 
     The hydraulic arm extension pivots on the hydraulic arm about a first horizontal axis z. The coupling rotates about vertical axis y and about a second horizontal axis z 1  while the array rotates about horizontal axis x. The hydraulic arm which supports the assembly may be telescopic and capable of gaining the height required for the trimmer to cut the crown of a mature tree. 
     In a preferred embodiment the coupling has a first double bracket pivoted vertically to the extension at the front end thereof, the first double bracket is fixed to a second double bracket which provides a horizontal pivot for the depending cutter arms and a ram connected between the first double bracket and the extension arm produces arcuate swings in the cutter arm. 
     The upper end of the cutter arm is pivotally connected to the second double bracket and a ram connected between the cutter arm and the second double bracket is operable to change the inclination of the array. 
     The lower end of the cutter arm is pivotally connected to the array box and a ram connected between the cutter arm and the array box executes the wrist action through 90 degrees. 
     The hydraulic arm extension has a pivot connection to the hydraulic arm and a fluid operated ram allowing the assembly to rotate about a third horizontal axis. 
     The cutters are circular saw blades which overlap circumferentially. 
     The array is linear and the blades are 800-990 mm in diameter and separated from each other by about 20 mm. 
     The invention may also be described as a mount assembly for the hydraulic arm of a vehicle which is capable of manipulating a tree trimming cutter, the assembly comprising a hydraulic arm extension which permits both rotation about a vertical axis permitting side to side sweeps and rotation about a first horizontal axis to adjust the inclination of the cutters to the ground, a cutter arm connected at one end to the coupling and pivotally connected at the opposite end to a multiple cutter array such that the array is rotatable about a second horizontal axis mimicing wrist action. 
     The hydraulic arm may in turn be pivoted to a jib extending from the rear part of the chassis of a tractor. The two together constituting a jib and dipper arm commonly used in rural infrastructure operations. In this way the trimmer may have an arc of operation of 14-16 m. 
     The multiple cutter array may be an elongated mount with a common drive for two, three or four circular saw blades. Thus a cutting band of 3-4 m is available. 
     The cutter array may rotate between a horizontal trimming path and a vertical trimming path, wherein the 90 degree rotation mimics wrist action. When the cutters are following a horizontal trimming path the cutter arm depends from the coupling. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       One embodiment of the invention is now described with reference to the accompanying drawings, in which: 
         FIG. 1  is a diagram of a tractor with a jib, dipper arm and cutter assembly according to the invention at ground level. 
         FIG. 2  is a side view of the trimmer assembly. Hydraulic hoses for the assembly rams have been omitted for clarity in this and the following two figures. 
         FIG. 3  is a perspective of the trimmer assembly of  FIG. 5 . 
         FIG. 4  is an opposite side view of the trimmer assembly. 
         FIG. 5  is a rear diagrammatic view of a tractor trimming in an upright plane. 
         FIG. 6  is a rear diagrammatic view of a tractor trimming in a horizontal plane. 
         FIG. 7  is a rear diagrammatic view of a tractor trimming at 45 degrees. 
     
    
    
     DETAILED DESCRIPTION WITH RESPECT TO THE DRAWINGS 
     Referring now to the drawings, in  FIG. 1  the 130HP tractor  2  has a chassis extension  4  to the rear of the back wheels  6  and the extension supports a circular slewing base  8  from which an upright jib  10  extends. Such equipment is supplied by Hiab Australia Pty Ltd. Jib arm  12  is pivoted to the top of the jib and is raised and lowered by ram  14 . Dipper arm  16  is pivoted to the end of the jib arm and in turn raised and lowered by ram  18 . The dipper arm  16  is telescopic and is adjusted by ram  20 . It is to the telescoping end of the dipper arm  16  that the trimmer assembly  22  is connected. 
     Referring now to  FIGS. 2 and 3 , the leading telescopic end of dipper arm  16  has a horizontal pivot  24  in the z axis about which arm extension  26  raises and lowers by the force of ram  28 . The leading end of the extension has a pivot pin  30  in the y axis about which coupling  32  rotates through 270 degrees. This rotation is the result of the action of ram  34  which is centrally mounted on upright pin  36  in turn mounted on brackets  38  which extend sideways from arm extension  26 . Ram  34  reacts on thrust pin  40  which extends between horizontal walls  42  of a first double bracket forming one half of coupling  32 . Ram  34  exerts its lateral force on pin  40  through link  42 . 
     The remaining half of the coupling is formed by a pair of parallel walls  44  which form a second double bracket. These walls support horizontal pin  46  from which cutter arm  48  depends. Walls  44  also support thrust pin  50  which enables ram  52  to rotate the cutter arm through 120 degrees about a second z axis. 
     Multiple cutter array  54  consists of a drive housing  56  to which is fixed hydraulic motor  58 . This drives all four 825 mm saw blades  60  at 25,000 rpm. The axis of the cutter array lies in an x axis and is rotatable about the x axis by a ram  62  held parallel to cutter arm  48  by brackets  64 . Ram  62  actuates cranks  66  to which housing  56  is welded. Such motion produces a wrist like action in the housing turning the blades through  90  degrees. The hydraulic motor  58  is driven by the tractor hydraulics through large diameter hoses  68 . These take the major part of the tractor output. 
     The assembly rams are supplied from the same tractor hydraulics by hoses  70  (see  FIG. 1 ) which are also slung under the dipper arm and suspended where possible to allow maximum movement to the arm extension  26 , coupling  32  and cutter arm  48 . Tank  72  holds hydraulic oil. Slewing ram  74  is mounted beside the jib. 
     The stability of the vehicle is improved if the jib is offset by a suitable distance. 
     Referring now to  FIGS. 5 ,  6  and  7 , in use the driver surveys the wooded site for powerlines, obstructions and limbs of trees likely to fall if struck by the cutter assembly. The driver drives the tractor on the grass verge alongside the trees to be trimmed and extends the dipper arm to reach the desired height. The blades are arranged through the hydraulic controls to lie parallel to the desired cut. The blades are rotated at cutting speed and the slewing control rotates the jib and dipper arm toward the growth  76  to be cut. The tractor progresses and the saw cuttings fall to the ground in advance of the tractor. The tractor drives over them but is followed by a mulcher which breaks them into compostable mix. 
     We have found the advantages of the above embodiment to be: 
     1. Trimming can produce geometric accuracy. It can also produce landscaping effects which are aesthetically pleasing. It can cut firebreaks in forests. 
     2. The cuts can be adjusted to ensure the felled branches are of a size which can be mulched by available equipment. 
     3. A speed of 3 km/hr is attainable. 
     It is to be understood that the word “comprising” as used throughout the specification is to be interpreted in its inclusive form, ie. use of the word “comprising” does not exclude the addition of other elements. 
     It is to be understood that various modifications of and/or additions to the invention can be made without departing from the basic nature of the invention. These modifications and/or additions are therefore considered to fall within the scope of the invention.