Wood processing systems and methods of constructing and using them

Information

  • Patent Grant
  • 6641065
  • Patent Number
    6,641,065
  • Date Filed
    Thursday, May 9, 2002
    22 years ago
  • Date Issued
    Tuesday, November 4, 2003
    20 years ago
Abstract
A generally horizontal wood comminuter has a crosswise rotor with comminuting knives moving in a path of rotation and a crosswise coacting anvil. A feed works provides a material support surface and a power-driven feed member above it for feeding material toward the rotor. The rotor is driven in an uphill path of rotation relative to the feed works. Lift arms pivotally carry the feed member for swinging vertical movement toward and away from the material support surface. A crosswise deflector plate is carried independently of the lift arms and extends toward the anvil and a crosswise lift arm plate coacts with the deflector plate to contain fragmented material. The anvil and a grate retainer preferably are pivotal to move together from an operative to an inoperative position. A torque limiting device controls the drive of the rotor.
Description




BACKGROUND OF THE INVENTION




It is to be understood that machines of this general character, which are in wide use today for recycling heavy wood products particularly, are of a portable nature in the sense that they can be drawn by tractors or may be self-propelled, can weigh up to 100,000 pounds, and may be up to 50 feet in overall length. Normally such machines, which employ heavy knifed hammers to demolish the wood, are powered by heavy duty diesel engines providing as much as 800-1,000 horsepower.




SUMMARY OF THE INVENTION




The present wood processing system incorporates a rotary drum having a plurality of peripherally supported comminuting members or hammers. Both uphill and downhill rotors are known and in use, and the machine depicted is an uphill rotor machine in which the rotor moves the material upwardly with respect to the horizontal feed of the material. An anvil is supported near the upper end of the machine just upstream of a grating system which facilitates easy maintenance and the ready changing of grates to provide a considerable selection of grate opening sizes and configurations. The material feed system includes a compression feed drum associated with a horizontal conveyor at the entrance to the comminuting drum or rotor and both are driven in a direction to move material to the comminuting drum. The present invention is concerned with various improvements in machines of this character. One of these involves the use of the downwardly swinging compression feed roll to facilitate upward swinging movement of the anvil and upper grate retainer member for maintenance and clearing purposes.




Another improvement is concerned with utilizing a comminuting drum shaft release system which prevents foreign objects, such as heavy metal bolts and fragments from damaging the machine. Still another improvement is concerned with the general construction of the machine including the stacked mounting of the comminuting drum drive shaft and the pivot shaft for the compression feed roll, and a top wall containment deflector plate which is separate from the compression feed roll assembly and pivots with the anvil.




A prime object of the present invention is to provide a rugged heavy duty machine, which can be economically operated at chosen locations, which might be at a landfill, or in the field at a demolition site.




A further object of the invention is to provide a safer machine which confines the material and does not throw it out in the manner that so-called horizontal tub grinders do.




A still further object of the invention is to provide a machine which is particularly designed to handle heavy waste wood material in an effective manner, while, at the same time, being so constructed as to be capable of being economically manufactured and sold at an economically attractive price.




Other object and advantages of the invention will become apparent with reference to the accompanying drawings and the accompanying descriptive matter.











GENERAL DESCRIPTION OF THE DRAWINGS




The presently preferred embodiment of the invention is disclosed in the following description and in the accompanying drawings, wherein:





FIG. 1

is a schematic side elevational view of the machine with part of the near side wall broken away to show elements of the machine;





FIG. 2

is a partly sectional fragmentary schematic side elevational interior view on an enlarged scale showing the feed drum in down position;





FIG. 3

is a similar view with the feed drum in raised position and with certain components omitted from the view for the sake of clarity;





FIG. 4

is a still further enlarged fragmentary side elevational view of the comminuting drum and drum grate system only;





FIG. 5

is a greatly enlarged side elevational view of a portion of the grate and grate retainer system only;





FIG. 6

is a view similar to

FIG. 3

with the cylinder for lifting the upper grate retainer hood reconnected to the hood;





FIG. 7

is a partly sectional fragmentary schematic view similar to

FIG. 6

, but showing the feed drum in down position and the upper grate retainer hood raised, certain components being missing from the view;





FIG. 8

is a similar schematic partly sectional fragmentary side elevational view illustrating elements used in the changing of the grate;





FIG. 9

is a side elevational view of one of the lower grate holder arms only;





FIG. 10

is a partly sectional top plan view of the comminuting drum drive shaft assembly only;





FIG. 11

is an enlarged sectional end elevational view showing the drive members in engaged driving position; and





FIG. 12

is a similar view showing the drive members in disengaged position.











DETAILED DESCRIPTION




Referring now, more particularly, to the accompanying drawings wherein a presently preferred embodiment of the invention is disclosed and directing attention initially to

FIGS. 1 and 2

, a letter M generally designates the wood processing machine which is shown as mounted on a trailer frame F which may be readily towed to the site of use, and which has a tow coupling mounted on one of its ends to facilitate coupling the machine to a towing vehicle. The trailer or machine frame F includes longitudinal channels or beams


10


and


10




a


connected by suitable cross beams or the like


11


at spaced intervals along the length of the machine. Wheels


12


, with tires


13


thereon, are journaled on axles


14


carried by the frame F and vertically adjustable columns


15


, with ground engaging pivotable plates


15




a


thereon, are movable in casings


16


secured to the frame F from a retracted position to an extended lowered position in which the support columns


15


, in conjunction with the wheels


12


, support the machine for operation in generally horizontal disposition.




At the front end of the machine, front and side walls


17


are provided to enclose a wood receiving conveyor system, generally designated C, which includes motor driven longitudinally extending endless chains


18


, traveling over a floor plate


17




a


around front and rear sprockets


19


mounted on shafts


20


jounaled by the frame F. Material supporting, transversely extending bars or plates may be provided to connect the chains


18


.




The walls


17


may be braced by suitable vertical stanchions


21


. Upstanding side walls


22


and


22




a


are provided on the frame F rearwardly of the walls


17


to extend rearwardly therefrom to collectively house a material feed wheel, feed member, or drum, generally designated


23


, and a wood shredding or fragmenting rotor or drum, generally designated


24


. The conveyor


18


and the wheel


23


, operating in conjunction, or either of them singularly, may be aptly termed a “feed works” for feeding material to be comminuted to the rotor drum


24


in a continuous longitudinal stream or flow of waste wood material.




The side walls of the machine,


22


and


22




a,


are supported by upper longitudinally extending beam members


22




b,


which connect to the upright side beams


21


. Vertically slotted aligned openings O (

FIG. 2

) are provided in side walls


22


and


22




a


and vertical shaft and bearing support plates


27


and


28


, which vertically abut at


29


are disposed in alignment with the openings O interiorly thereof. The lower plates


28


, in

FIG. 2

, carry the comminuting drum drive shaft


30


and the plates


27


carry the feed drum pivot shaft


31


in a state of vertical alignment. Once the shafts


30


and


31


are inserted through the openings O at each side of the machine when plates


27


and


28


are lowered into position, the ends of the shaft


30


may be captured by shaft journaling bearings, generally designated


32


, which comprise a lower half


33


supported on plates


34


and


35


carried by the side walls


22


and


22




a


of the machine M and upper bearing parts


36


which bolt to the lower bearing parts


33


as at


36




a.


Vertical retainer bars


26


and


26




a


bolt over the plates


27


and


28


to the side walls


22


and


22




a


to secure the plates


27


and


28


in fixed position. Suitable bearings (not shown) are also provided to journal shaft


31


.




The feed drum


23


is shown in lowered position in FIG.


2


and in raised position in FIG.


3


. Feed drum side plate assemblies, generally designated


38


, connected by arm portions or arms


38




a


to laterally spaced bushings


39


, received on shaft


31


, support the shaft


40


of feed drum


23


via bearings


41


provided on the side plate assemblies


38


. The side plate assemblies


38


or support assemblies, which between them carry feed drum or feed member


23


, include curved walls


38




b


and


38




c


which effectively span the arms


38




a


of the assemblies


38


which lie adjacent to side walls


22


and


22




a


and keep wood fragments from entering or leaving the comminuting region along the upper end of the feed drum or feed member


23


when it is in lowered operative position. A curved wall


38




d


connects walls


38




b


and


38




c


which may be referenced as lift arms. An anvil frame or anvil plate assembly AF, to which anvil A is fixed, is stationary when the machine is in operation and also mounts a top containment wall and material deflector plate


37


which normally is in fixed position. The frame AF which includes arms


37




a


fixed to wall


37


is fixed to bushings B which are pivotal on shaft


31


between the bushings


39


to permit anvil frame AF to pivot upwardly thereon when the machine is not in operation.




A feed drum shaft


40


(

FIG. 2

) has drum end plates


42


, forming a part of assemblies


38


, which support wood engaging and driving toothed members


43


constituting a peripheral drum surface as usual, generally designated


44


. A suitable reversible rotary hydraulic motor, generally designated


45


, and supported by one of the side plate assemblies


38


may be coupled to the shaft


40


for purposes of driving it in the direction indicated, or in the opposite direction of rotation. Double acting hydraulic cylinders


46


connected to the side plate assemblies


38


as at


47


, and to a bracket


48


fixed on vertical frame stanchions


49


at


50


, is utilized in moving the drum


23


from the position shown in

FIG. 2

to the position in which it is shown in FIG.


3


.




The cutting or chipping drum


24


, which is shown as rotated in the uphill direction by the arrow x in

FIG. 2

, has a rotary drum periphery


51


extending from end to end of the drum


24


which includes a series of cutting teeth or comminuting members


52


in suitably spaced tool holders


53


. For purposes of convenience, only several of the many laterally and circumferentially spaced teeth


52


are shown in the drawings.




As

FIGS. 2-8

particularly illustrate, the periphery of the cutting drum


24


is partly surrounded by perforate grate members


54


,


55


,


56


, and


57


(FIG.


4


), which, as

FIG. 5

shows, are provided with grate openings


58


. These grates


54


-


57


, which all have the openings


58


, extend lengthwisely or axially across the periphery of the drum, and are held in place by a grate retainer mechanism, generally designated


59


(FIGS.


4


and


5


). The retainer mechanism has holding elements or arms


63


which pivotally mount at


60


to a frame F frame member


61


. The mechanism


59


includes a pair of stationery end tracks


62


, which embrace the ends of the grates


54


-


57


and are supported by frame members


61


upon side walls


22


and


22




a,


or in some other suitable manner. The intermediate clamp arms


63


(FIG.


5


), which pivotally mount on shaft


60


, are moveable sufficiently peripherally outwardly from the knife drum


54


to permit changing of the grates


54


-


57


.




It is to be understood that the grates


54


-


57


are very heavy and typically are handled by a chain hoist device, generally designated


64


, in FIG.


8


. The chain hoist device


64


is moveable on rollers


65


along longitudinal tracks


66


. The chain hoist device


64


is shown in

FIG. 8

in the process of lifting an uppermost grate


67


having the same openings


58


. Grate


67


is retained by an upper grate retainer device


74


forming a part of anvil frame AF, but also may be used to lift any of the grates


54


-


57


once the pivotal retainer arms


63


are released and swing outwardly sufficiently to clear the grates for upward sliding removal guided by fixed end supports


62


and curvilinear plates


70




b.






Wood chips of the proper and desired size pass through the grate openings


58


and the various grates


54


-


57


and


67


, and are removed by an underneath endless conveyor, generally designated


68


. As shown, the chip take away conveyor


68


includes endless belts


69


trained around pulleys


70


in the usual manner and driven by motors powered by the engine E of the machine.




A laterally extending grate support member, generally designated


70




a,


which spans the grate assembly G and bolts to the frame side walls


22


and


22




a,


has blocks


71


with front edges cut away as at


71




a


to accommodate the stepped configuration


63




a


provided on each of the arms


63


(

FIG. 9

) and function as a stop, limiting radially outward swinging movement of the grate support arms


63


. The curvilinear plates


70




b,


forming a part of the member


70




a,


extend to meet the marginal abutting edges of the grate plates


56


and


57


. The plates


70




b


have triangularly shaped gussets


70




c.


Bolts


171


extending through the blocks


71




b


and threaded through nuts


171




a


are adjustable to engage and hold the arms


63


in grate retaining position. The bolts


171


are backed off when it is desired to release the arms


63


to move outward and rest on nuts


171




a.


The curved plates


70




b


do not exert sufficient pressure on the grates to prevent withdrawal of the grates upwardly and function as grate supports. At their upper ends arms


63


have straps


72


, with flared ends


72




a,


fixed to them for a purpose to be presently described.




As noted previously, the system also includes an upper grate


67


, which is in abutting engagement with the plate


57


, and is held in place by the anvil frame housing or hood member


74


, which can be raised outwardly away from the position in which it is shown in

FIG. 2

to the position shown in FIG.


7


. It will be seen that a double acting hydraulic cylinder, generally designated


75


and pivotally received on a mount bracket


76


connected to the side plate assembly or housing


38


, has a piston rod


77




a


normally inactively pivotally connected to a mount


78


on assemblies


38


. Anvil frame AF, and hood


74


are mounted for pivotal movement on the shaft


31


by the sleeve or bushing members B, which interleave with the sleeve or bushing members


39


that mount the feed drum assembly


38


pivotally on the shaft


31


. Guide members


72




b


on the hood


74


in alignment with arms


63


are received in and guide on the flared ends


72


on arms


63


when the hood


74


is in grate retaining position.




To remove grate retaining hood


74


, the assembly or housing


38


is first moved to the raised position shown in

FIG. 3

from the operative position shown in

FIG. 2

by the double acting cylinders


46


. When in this raised position, the piston rod


77




a


can be decoupled from the mount


75




a,


extended, and pivotally attached to a bracket


77




b


provided on housing


74


as shown in FIG.


7


. With the system disclosed, lifting of the grate retaining housing or hood


74


is readily accomplished using the weight of the feed drum assembly


23


returning to operative position, the weight of plate


37


, and cylinder


75


with its relocated piston


77




a.


Cylinder


75


later can control the restoration of the housing


74


to the closed grate embracing position when an upper grate


67


is restored to position. With the piston


77




a


in its maximum position of extension, the cylinder


75


and piston rod


77


initially function as a lever connected to the assembly


38


which causes the housing


74


to be initially lifted away from the grate


67


and then complete the final movement to the

FIG. 7

position.




The shaft


30


extends through one of the side walls


22


and


22




a


to be driven by a belt operated sheave


76


(

FIG. 10

) via a torque limiter device, generally designated


76




a,


which now will be described. The belt sheave


76


is driven appropriately by belts


76




a


connected with a drive


76




b


operated by the diesel engine E. The torque limiter


76




a


comprises a series of circumferentially spaced torque limiting devices, generally designated


77


(FIG.


11


), which operate, under normal conditions, to couple a flange


78


keyed to shaft


30


to a flanged part


79


fixed to the sheave


76


but rotatable on shaft


30


. Part


79


incorporates a drive disc


79




b


attached to sheave web


76




b


by bolts


76




c.






To understand the operation of the torque limiting devices


77


, attention is directed to

FIG. 11

which shows the members


78


and


79


in engaged position and to

FIG. 12

which shows them in disengaged position. Each of the six circumferentially spaced torque limiting devices which are utilized includes adjoining fittings


79




a


and


78




a


which are received within normally communicating openings


79




b


and


78




b


provided in the flanges


79


and


78


, respectively. The fitting


79




a


is secured to the flange member


79


by a bolt member


81


and the fitting includes an enlarged recessed portion


82


, which in the engaged (driving) position, receives a portion of a drive ball


83


, which is retained in the bore


84


of the sleeve fitting


78




a.


A slideable plunger


85


, extends into the sleeve fitting


78




a


from a torque limiter end housing portion


86


, and it will be seen that the plunger


85


has an enlarged flange portion


87


inward of a ball accommodating valley or recess


89


with a sloped wall


90


.




The plunger


85


is retained axially by means of a system of race forming members


91


and


92


acting on a circle of balls


94


. The members


91


and


92


are loaded by the spring pressure of a spring, such as a coil spring


93


. Screw member


95


threadingly engaged at


96


with the interior of housing bore


86


and alters the spring force as required for the torque limiting operation desired.




In a situation in which the cutting drum


24


should become jammed and not be free to rotate with the sheave flange


76




b,


the flange


79


will force each ball


83


to escape its socket


82


and cause each plunger


85


to be forced through each circle of balls


94


, overcoming the spring loading on the angled races


91


and


92


. Thus, the drive motor or engine for rotating the drum and the drum is protected without the necessity of the grates being disengaged when foreign matter is encountered in the wood fed to the machine. Typically for material jams between the grates and the rotating comminuting drum in such horizontally fed machines, the previous solution to the problem has been a disengageable grate which is forced to a disengaged position.




In the present machine once the foreign matter has been removed, the resetting of each torque limiter is a simple matter of first aligning the flanges


78


and


79


so that each ball


83


is opposite a cavity


82


and then pushing the plungers


85


toward the flanges


79


to permit each circle of balls


94


to return to original position. It is to be understood that the torque limiter described is a commercially available unit.




The Operation




In operation, the material to be comminuted is fed from the conveyor chains


18


to a position beneath the feed drum


23


, which is in the position shown in FIG.


3


. It will be raised upwardly as necessitated by the flow of material. The wood is advanced forwardly toward the comminuting drum


24


by the combined forwarding action of the conveyor chains


18


and the feed drum


23


. Material processed forwardly by the conveyor chains and the drum


23


into the path of the teeth


52


on drum


24


is initially fragmented by the teeth


52


and moved upwardly between the drums


22


and


24


where it is contained by the deflecting surface or plate


37


which substantially spans the area between side walls


22


and


22




a


and extends to a position just short of the curvilinear shield


38




c.


With wall


37


remaining in fixed position regardless of the position of the feed drum


23


which moves upwardly and downwardly with the height of material being fed under feed drum


23


, the deflection of material to the also fixed anvil A remains constant and controlled. The moving housing portion


38




c


contains the fragments of materials and deflects them toward plate


37


which directs them to pass beneath anvil A where they are further reduced or comminuted. Thereafter, if they are of sufficient size to pass through the grate openings in the overall grate G, they do so and, of course, the grate assists further fragmentation in view of the limited clearance, i.e. five-eighths of an inch, between the fixed teeth


52


on the rotating drum


24


and the grate G.




As indicated should a foreign non-fragmentable body become jammed between the grate G and the drum


24


, the torque limiters will disengage the drive motor from drum


24


which is held stationery by the jammed condition. As indicated earlier, when the jammed condition is relieved and the flanges


78


and


79


restored to the engaged position of peripheral alignment shown in

FIG. 11

, the plungers


85


may simply be readily pressed inwardly to restore the balls


83


to an engaged position in which torque is transmitted once again to the drum


24


.




To obtain access to the front portion of drum


24


, cylinder


46


can be activated to swing the drum


23


from the position shown in

FIG. 2

to the raised position shown in FIG.


3


. In this position of the parts, it will be noted that cylinder


75


is inactively connected to bracket


75




a.


To remove the upper grate


67


, which is retained by housing or hood


74


, the piston rod


77




a,


of the cylinder


75


, may be unhooked from brackets


75




a,


power extended, and reattached to bracket


77




b


provided on the hood member


74


. Accordingly, when the cylinders


46


are operated to restore the feed drum


23


to operative position, the weight of this assembly will initially lift the frame AF and relatively heavy housing


74


from the position shown in

FIG. 2

to a position in which it is partly removed from the grate


67


, and with this momentum, piston rod


77


can then be retracted to complete the upward swing of retention hood


74


.




The chain hoist


64


, traveling on trolley


65


, may then have its hook


64




a


extended through one of the openings in grate


67


, which may then be lifted off as

FIG. 8

indicates is occurring. The grate sections


54


-


57


may be removed by sliding them upwardly, once the retainer arm members


63


are released by backing off bolts


71


and swung outwardly to rest the on stepped members provided on member


70




a.


Hooks


64




a,


are also employed, in this further removal of the heavy grate sections.




The disclosed embodiment is representative of a presently preferred form of the invention, but is intended to be illustrative rather than definitive thereof. The invention is defined in the claims.



Claims
  • 1. A method of controlling a generally horizontal wood material comminuting machine having a generally longitudinally disposed frame with spaced apart side walls having front and rear ends, a crosswisely extending rotatably mounted rotor shaft having a rotor with a periphery comprising comminuting members movable with said rotor in a path of rotation, a crosswisely extending anvil carried on said frame to coact with said comminuting members and reduce said material, a drive for moving said rotor shaft and rotor in a path of rotation past said material support surface, a feed works connected with said frame in front of said rotor including a power-driven feed member having a generally horizontal axis extending generally parallel to said rotor axis mounted above said support surface, support arms pivoted on said frame rearwardly of said feed member pivotally carrying said feed member for swinging vertical movement toward and away from said material support surface, and a grate assembly downstream from said anvil supported by said frame adjacent said path of comminuter rotation to embrace a portion of said rotor path downstream from said anvil, including:a. providing a disengagable torque limiting device; and b. connecting said device between a drive sheave at one end of said rotor shaft and a plate fixed on said rotor shaft, said torque limiting device comprising a series of ball receiving circumferentially spaced wells in one of said plate and sheave, and a series of balls urged normally by spring-pressed plunger members partly into said wells in shaft driving position, there being plunger housings carried by the other of said plate and sheave in which said plungers are slideable between an operative position maintaining said balls in shaft driving position in said wells and an inoperative position in which said plungers are forced to an inoperative position by said balls to disengage said drive from said plate and rotor shaft when said rotor shaft is prevented from rotating by foreign material jams.
  • 2. A generally horizontal wood material comminuting machine comprising:a. a generally longitudinal frame with front and rear ends and spaced apart side walls; b. a transversely extending rotatably mounted rotor shaft comprising a rotor with a periphery of comminuting members moving in a path of rotation; c. an anvil plate assembly including a transversely extending anvil pivotally carried on said frame above said rotor shaft to coact with said comminuting members in reducing said material; d. a feed works connected with said frame forwardly of said rotor including a material support surface on which said material is supported and a power-driven feed member having a generally horizontal axis extending generally parallel to said rotor axis mounted above said support surface for engaging said material and feeding it along said support surface towards said rotor; e. a drive for moving said rotor shaft and rotor in an uphill path of rotation upwardly past said material supply surface; f. supports pivoted on said frame rearwardly of said feed member carrying said feed member for swinging vertical movement toward and away from said material support surface; g. a grate assembly downstream from said anvil comprising a series of crosswisely extending curvilinear grate plates supported by said frame adjacent said path of comminuter rotation and including an upper grate; and h. a grate retainer housing fixed to said anvil plate for pivotal movement therewith releasably holding said upper grate in position when said anvil is in operative position.
  • 3. The machine of claim 2 wherein said anvil operatively comprises a generally vertically disposed plate and a disengageable link is provided which is connectable between said supports and said anvil plate assembly when said feed member is in a raised position to permit the weight of the descending feed member to assist swinging of said anvil plate and grate retainer housing to a raised inoperative position.
  • 4. The machine of claim 3 wherein said link includes a fluid pressure operated cylinder which is actuatable to assist said swinging movement of said anvil plate and grate retainer housing to raised inoperative position and to control return swinging to operative position.
  • 5. A method of operating a generally horizontal wood comminuting machine having a generally longitudinally disposed frame with front and rear ends and spaced apart side walls, a crosswisely extending rotatably mounted rotor shaft on said frame mounting a rotor having a periphery comprising comminuting members movable in a path of rotation, a crosswisely extending anvil plate carried on said frame above said rotor shaft to coact with said comminuting members in reducing said material movable from a generally vertical operative position to a raised position, a feed works connected with said frame forwardly of said rotor including a material support surface on which said material is supported and a power-driven feed roll member having a generally horizontal axis extending generally parallel to said rotor axis mounted above said support surface for feeding material along said support surface towards said rotor, a drive for moving said rotor shaft and rotor in an uphill path of rotation upwardly past said material support surface, a support assembly pivoted on said frame rearwardly of said feed roll member pivotally carrying said feed roll member for swinging vertical movement toward and away from said material support surface, a grate assembly downstream from said anvil comprising a series of crosswisely extending curvilinear grate plates supported by said frame adjacent said path of comminuter rotation and including an upper grate, a grate retainer housing for releasably holding said upper grate in operative position fixed to said anvil to pivot therewith, and a link carried by one of said feed member support assembly and said anvil plate and grate retainer assembly which is connectable between them, comprising:a. raising said feed member roll to an upper position; b. connecting said link disengageably between said support assembly and said anvil plate and retainer housing assembly; and c. lowering said feed member roll from raised position to permit its weight to assist swinging movement of said anvil plate upwardly to inoperative position and said retainer housing upwardly to an inoperative position permitting removal of said upper grate.
  • 6. The method of claim 5 wherein said link is provided as a double-acting fluid pressure actuated cylinder and said cylinder is actuated to assist in raising said anvil plate and retainer housing and in controlling its descent to operative position.
Parent Case Info

This application is a division of U.S. application Ser. No. 09/716,532 filed Nov. 20, 2000, now U.S. Pat. No. 6,474,579. This application claims the priority of provisional application Ser. No. 60/170,043 filed Dec. 10, 1999, which is identically entitled. This invention relates particularly to machines known commercially as “wood hogs” for recycling heavy wood material, such as old railroad ties, the heavy pallets used widely in industry, the structural timbers which remain from the demolition of old buildings, heavy wood scrap, and many other such items. Horizontally fed machines of this character are in wide use and a machine of this type is the subject of U.S. Pat. Nos. 4,771,953 and 5,713,525, which are owned by the applicant's assignee and are incorporated herein by reference.

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Entry
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Provisional Applications (1)
Number Date Country
60/170043 Dec 1999 US