CA1231627A - Tree residue reduction apparatus - Google Patents

Abstract

ABSTRACT
Improved apparatus for reducing, to a smaller size, residue or debris left behind after a tree processing or har-vesting operation. The apparatus includes a first reduction unit which includes a plurality of cutter knives radiating outwardly from a hub at positions spaced circumferentially therearound and longitudinally therealong and cooperate with fixed knives to reduce the residue to smaller size. Down-stream there is located a second reduction unit (a common hammer mill) and downstream therefrom a fan unit for deliver-ing the reduced sized particles to a collecting container or other area. The units preferably are vertically oriented i.e. stacked one on top of the other resulting in self-feeding from one unit to the unit therebelow. If desired an impeller infeed means can be utilized for infeeding the material to the cutters of the first stage reduction unit. The apparatus may be permanently mounted at a suitable location or alternatively mounted upon a self-propelled mobile vehicle movable from one location to another and towing a trailer having a chip collect-ing or debris collecting container mounted thereon. To over-come clogging problems the cutter knives of the first stage unit have baffles mounted thereon extending in a direction parallel to the axis of rotation of the cutter knives. These baffles or impeller blades facilitate the flow of debris through the apparatus. Another embodiment to reduce clogging involves having the fan blades cutback at their attachment to a hub which is mounted for rotation to facilitate infeed of material to the fan unit. The cutback of the blades effective-ly provides an open generally conical infeed path along a por-tion of the depth of the blades about the axis of rotation thereof. The two different embodiments can be used individual-ly or in combination.

Description

3L;23~G~

TITLE OF THE INVENTION

Improvements in Tree Residue Reduction Apparatus FIELD OF INVENTION

This invention relates to apparatus for processing residue or debris left behind after a tree processing or harvesting operation The residue normally consists of branches, tree 10 tops and the like BAC~GROUND`OF INVENTION
-Collection and processing of logging residues or debris 15 into a more concentrated form can be accomplished using land clearing equipment and mobile chippers Productivity, however, is relatively low and costs are relatively high and thus commercially uneconomical There are a number of problems associated with processing 20 tree logging debris and residue, some of which include the size of the material, damage to chipper knives by rocks and other foreign material and a general under utilization of equipment capacity It has been found that the collection of processing recovery is affected by the size of the debris or residue 25 material; the proportion of original residue recovered in the form of processed material being substantially lower for small diameter material.
There have been a number of proposals for handling log-gong residue including mobile chippers, stump splitters and 30 the like A residue processor is disclosed in Canadian application 436,297 filed September 8, 1983 and which is an earlier imp provement to that disclosed in Canadian application Serial No 396,223 filed February 12, OWE

I

~L23~L6~7 The apparatus disclosed in the aforementioned applications is basically a mobile residue pickup and processing apparatus where at the front of the vehicle there is located a housing having a driven pickup assembly thereon for picking up residue such as branches, tree tops and the like left on the ground following a tree harvesting operation The pickup apparatus operates in cooperation with cutting knives to cut up the residue into smaller pieces and means have been pro-voided in an attempt to ensure the smaller cut up pieces do 10 not accumulate and clog the passage through which they move during operation of the machine In, one of the earlier aforementioned applications there is an improvement where accumulation prevention means is provided and in one instance comprises impeller means for propelling the cut up debris 15 through the passage and in another instance comprises additional cutting knives mounted at the base of a slot through which the pick up arms pass While effective, these proposals have not been completely successful In cop ending Canadian Application Serial No J 436,297 20 filed September 8, 1984 in the name of Douglas Do Hamilton et alp there is disclosed a vertically oriented apparatus where material is inked to a hopper at the top and thereafter by gravity passes downwardly through a first debris reduction unit to a second debris unit and into a fan unit for pro-25 polling the cutup residue into, for example, a residuecollectorO The units are stacked vertically one on top of the other and from experience of operating prototypes it has been found clogging will sometimes occur in the first stage reduction unit and/or the intake to the fan discharge 30 unto SUMMARY OF INVENTION

An object of the present invention is to provide improve-35 mints in the aforementioned apparatus to reduce the tendency of clogging during use of the apparatus ~L23~6~:7 A specific object of the present invention is to provide an apparatus where there is a two stage reduction of residue followed by a fan unit means for discharging the reduced particles and means to facilitate the flow of material through the apparatus and thereby overcome some of the clog-gong problems encountered with similar known equipment In accordance with the present invention there is provide Ed apparatus for reducing residue such as branches, tree tops or the like resulting from tree harvesting operations into smaller particles comprising (a) a first residue reduction unit having a plurality of cutter knives radiating from a hub at positions spaced circumferential there around and longitudinally thrilling, (b) a second residue reduction unit downstream of said first unit, (c) a fan type residue discharged unit downstream of said second residue reduction unit and (d) means lo reduce the tendency of clogging of at least one of said first residue reduction unit and said fan type discharge unit.
The units of foregoing paragraphs a, b, and c are prefer-rawly mounted vertically one on top of the other so that the flow of material from one unit to the other is assisted by gravity The clogging reducing means in one instance con-sits of baffles or impeller blades mounted on at least some - of the cutter knives of the first residue reduction unit wherein such baffles extend in a direction parallel to the axis of rotation of the cutter knives In another instance the blades of the fan type residue discharge unit are cut back adjacent the hub on which they are mounted so as to provide effectively a conical indeed area extending along a portion of the depth of the blades facilitating the indeed of debris to the fan discharge unit The two different clogging reduce in means may be used individually or in combination 1~3~6~7 LIST`OF'DRAWINGS

The invention is illustrated by way of example with reference to the accompanying drawings wherein:
Figure 1 is a vertical side elevation Al view of a self-propelled residue processor provided in accordance with one aspect of the present invention;
Figure 2 is a partial sectional right-hand elevation Al view of the processing assembly on the mobile vehicle illustrated in Figure l;
Figure 3 is a right-hand elevation Al view of Figure 2;
Figure 4 is a partial sectional vertical elevation Al view of an upper portion of the debris first stage reducing apparatus illustrated in Figure 4;
Figure 5 is an oblique view of the second stage of the residue reduction apparatus; and Figure 6 is a partial oblique view of a cutter knife of the first stage reduction unit having a baffle mounted there-on in accordance with the present invention, DESCRIPTION OF PREFERRED EMBODIMENTS

Referring to the drawings, there is illustrated in Figure 1 a mobile self-propelled residue processor 100 towing a trailer 200 for collecting the processed residue The mobile processor 100 comprises a mobile self-propel', led vehicle 101 having an extendible and retractable boom 102 mounted thereon with a grapple 103 at the free outer end thereof. The extendible and retractable boom is attached to an operator's cab unit 104, the controls for the machine being located in the operator's cab and which is rotatable ; mounted to slew about a vertical axis so that the operator is always located at a position appropriately to see what is ; being handled and grasped by the grapple. In broken line the grapple is illustrated holding a load of debris 105 prior to being dropped into the residue processing portion of the apparatus.

~L~3~L6~7 The residue processing apparatus comprises a first nest-due reduction unit 106 located vertically above a second nest-due reduction unit 107 and which discharges into a fan blower unit 108 that conveys the mutilated or broken up residue to the container on the trailer 200 by way of a conduit 109.
The first residue reduction unit 106 (shown in partial sectional view in Figure 1) has a hopper lo on the upper end thereof for receiving residue to be processed, the residue being dropped whereinto by the grapple 1030 The residue is 10 broken up by a plurality of arms 111 or cutter knives mounted on a shaft or hub 112 driven for rotation by one or more hydraulic motors 1130 The arms ill are spaced apart from one another circumferential around the shaft or hub 112 and spaced longitudinally thrilling and cooperate with fixed cut-15 ton knives 114, (see Figure 4) on the housing, during rotation to break the residue into smaller pieces It is intended that the apparatus 106 be designed such as to effectively meter the residue being fed to the second reduction unit 107 and this can be accomplished by various 20 means One consideration is that the hub 112 can be rotated at various different speeds At slower rates of rotation of the hub the peripheral spacing between the arms 111 effectively provides a wider gate or door for receiving material to be processed, while at higher speeds the amount of material grasp-25 Ed by the arms would be substantially less and thereby reduce the amount of residue being processed and fed into the second stage processing unto The spacing of the arms 111 from one another peripherally around the shaft can be varied by any convenient means, for example, by mounting such arms on a 30 collar attached to the hub and which can be variously position-Ed thereby adjusting the gap between adjacent arms in the same plane. Also, longitudinally along the shaft the arms can be variously positioned, one relative to another, at different peripheral locations and/or aligned with one another depending 35 upon the material and residue being processed. Some export-mentation will be required as to the type of residue being ~23~6~

processed relative.to-the:positioning of the knives or cutter arms 111 to accomplish the desired results.

The first residue reduction unit 106 is of the type disk closed in applicants aforementioned applications and further details of the same is believed unnecessary at this time.
reference to such applications may be had for further details of the same and the subject matter thereof is incorporated herein by reference thereto The second residue reduction unit 107 is a conventional hammer mill illustrated in Figure 5 and which is a Type A
hammer mill identified as a Jeffrey hammer mill by Dresser, or any other type The hammer mill 107 has a housing 120 in which there is located a rotary cutter unit 121 driven by a hydraulic motor 122 through a gear reduction unit 1230 The rotor 121 is relatively massive and thus there is substantial inertia or momentum for receiving and leveling out energy requirements in handling a fluctuation in the flow from the first residue reduction unit 106. This inertia energy can be utilized effectively to control the flow of material from the first reduction unit 106 to the second reduction unit 107.
: For example, the inertia affect can be utilized in handling overloads by cutting off power requirements to motor 122 and diverting hydraulic fluid flow to the motors 113 of the first reduction unit so as to speed up the same and thereby cut down the amount of residue being processed by the same or at a greater speed cutting it up into finer material, thereby reducing the load on the second reduction unit 107.
The hammer mill 120 illustrated in the drawings is a hammer type wherein the hammer units are pivotal mounted on a disk rotatable on a shaft and operating in conjunction with a fixed screen. Alternative to this fixed cutter type units can be mounted on the rotor and cooperate in a conventional manner with other fixed cutters in the housing unit.

~23~6 Discharge from the second residue processor 107 is direct-lye into a power driven fan unit 108 that brows the broken up residue through conduit 109 into the collector 200.
The first residue reduction unit 106, the second residue reduction unit 107 and the fan 108 can all be driven by hydraulic motors and the circuitry thereof may be interrelated one relative to another so as to maximize the utilization of power and divide power requirements from one unit to the other to provide an efficient system for handling varying size and quantities of residue being processed. The power sources for the various units may be independent of one another or interrelated Preferably the drive for unit 107 is a direct drive with an interrelated or integrated drive therefrom for unit 1080 It is primarily intended the first indeed reduction unit should be automatic self-feeding by rotation of arms Lowe However, should indeed to such reduction unit be hampered by the type of material being fed thereto, additional propelling means may be utilized, for example, a plurality of arms radiating from shafts which are rotatable about axes parallel to the shaft on which arms 111 are mounted but spaced laterally therefrom so as to direct the debris to be processed into the processing area In the foregoing, there has been described briefly, means for automatic feed from the first processing or debris reduce lion unit to the second reduction unit, the latter of which may be referred to as a common hog unto The motor driving the hog unit may be co-related to the drive of the first debris reduction unit so that the speed on the hog motor increases or decreases relative to the speed of the first reduction unit, depending upon the requirements to ensure there is a constant feed from one to the other of the two units ~3~6~t7 From experience gained in operation of a prototype of the apparatus disclosed in the aforementioned Canadian Application Serial No 436,297, clogging has been found to occur sometimes in the first reduction unit 106 and/or fan discharge unit 1080 Clogging occurs in the first reduction unit when the cutup debris therein fails to flow there through and into the second reduction unit It has been found the clogging of such unit can be substantially reduced by adding baffles to the cutter knives 111= Referring to Figure there is illustrated one cutter knife 111 with a curved baffle Lola projecting laterally therefrom The baffle Lola projecting laterally therefrom.
The baffle Lowe extends from the hub lllb and is curved in the same direction as the cutter knife 111 generally following the contour thereof terminating in an outer end lllc sub staunchly behind the tip hid of the cutter knife in reference to the direction of rotation of the cutter knife While the baffle Lola is illustrated as being curved and connected to the hub it could alternatively be a straight baffle extending only along a portion of the length of the cutter knife.
Experimentation will be required for the most effective length and shape of the baffle for propelling of different types of material to be processed The baffle serves as a positive means for propelling the material through the reduction unit but, dependent upon the speed of rotation, may also be effect-ivy as an air moving means facilitating propelling the cutup ; debris through the reduction unit into the second stage reduction unit.
With respect to air flow through the systems, and which facilitates the flow of material through the various units, in Figure 2 it will be noted the second stage reduction unit 107 has baffle units or deflector plates aye From Figure 3 it will be noted these baffle plates slope outwardly and downward-lye providing an inflow air path designated by the arrow A.
These deflector plates can, if desired, be hingedly (or slid-ably mounted) to selectively vary the intake area of the airflow path and thereby selectively adjust the amount of air flow ~23~
g The cutup residue from the second reduction unit 107 is directed by way of walls 107b into the fan unit 1080 The fan unit has a plurality of blades aye (preerrably flat) secured to and radiating outwardly from a hub 108b on a shaft journal-led by suitable bearing means for rotation about a vertical axis and driven by a hydraulic motor kiwi It has been found clogging of the fan unit can be substantially reduced by cutting back the blades generally along a line designated 108d.
; The line 108d is illustrated generally in alignment with the wall 107b defining the discharge from the second reduction unit. Effectively the cutback in the blades leaves an open conical indeed area designated D (see Figure 3) that extends along a portion of the depth of the blades the depth being measured parallel to the axis of rotation of the hub 108b.
The debris from the fan unit 108 discharges from an outlet eye into the discharge conduit loo The second reduction unit 107 is driven by an internal combustion engine Ml connected by a drive shaft DO by way of an overriding clutch C to the drive transfer unit 123~ The drive transfer unit 123 also drives the hydraulic motor 122 which supplies fluid pressure by way of line aye to the motors 1130 Motor Ml also drives a hydraulic pump My providing fluid pressure by way of line Ma to the hydraulic motor 108c which by way of a belt drive 108f drives the shaft 108b of the fan unit. The hydraulic motor 108c additionally is connected to a drive shaft 108h which by way of an angle gear box 108j is connected to the shaft 108k of the hammer mill 1070 As previously mentioned there is considerable momentum energy in the hammer mill and this energy can be utilized to drive motor 108c when the rotational speed of the fan is reduced by over-loading of the fan with debris material The drive system from the hammer mill shaft aye to the motor 108c is through a torque limiting device The purpose of the arrangement is to use the kinetic energy of the hammer mill to drive the blower when there is an overload on the latter and thereby reduce the tendency of clogging SLY

In summary of the foregoing there axe three different propositions for reducing clogging one being the addition of baffles in the first stage reduction unit, the other being a modification to the shape of the blades in the fan discharge unit and the third being utilization of the momentum of the rotor in the second reduction unit to provide additional power input to the drive of the fan unit. These different proposals may be used individually in combination or in sub combinations thereof . .,

Claims (8)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. Apparatus for reducing residue such as branches, tree tops or the like resulting from tree harvesting operations in-to smaller particles comprising:
a) a first residue reduction unit which includes a plurality of cutter knives radiating outwardly from a hub at positions circumferentially spaced therearound and axially therealong;
b) a second residue reduction unit downstream of said first unit;
c) a fan type residue discharge unit; and d) means to reduce the tendency of clogging of at least one of said first residue reduction unit and said fan type discharge unit.

2. An apparatus as defined in Claim 1 wherein said units are stacked vertically one on top of the other such that the feed of material from one to the other is assisted by gravity.

3. An apparatus as defined in Claim 1 wherein said means to reduce clogging comprises baffle means secured to at least some of the cutter knives of said first residue reduction unit and extending in a direction parallel to the axis of rotation of said cutter knives.

4. Apparatus as defined in Claim 3 wherein said baffle plates are curved and extend partially along the length of the cutter knife associated therewith.

5. The apparatus as defined in Claim 4 wherein said baffle plates extend from a hub on which the cutter knives are mounted and are curved and extend longitudinally along the knife ter-minating at a position spaced rearwardly from the tip of the knife with reference to the direction of rotation thereof.

6. Apparatus for reducing residue such as branches, tree tops or the like resulting from tree harvesting operations in the field into smaller particles comprising:
a) a first residue reduction unit which includes a plurality of cutter knives radiating outwardly from a hub at a position spaced circumferentially therearound and axially therealong, b) a second residue reduction unit downstream of said first unit and c) a fan type residue discharge unit, said fan type residue discharge unit having blades thereon and cutback to provide effectively a conical intake path tapering inwardly in a direction from the second residue reduction unit to the fan unit.

7. Apparatus for reducing residue such as branches, tree tops or the like resulting from tree harvesting operations comprising at least one residue reduction unit for reducing the debris to smaller sizes and followed by a residue dis-charge unit comprising a fan having a plurality of blades with an inlet thereto being effectively a conical path tapering inwardly in a direction from the residue reduction unit to the fan unit.

8. Apparatus as defined in Claim 7 wherein said conical path is defined at least in part by a cut out portion on each blade of the fan unit, said cut out portion extending along a portion of the depth of the blade adjacent a hub on which said blades are mounted and radiate outwardly therefrom.