US3701483A

US3701483A - Railroad tie shredder

Info

Publication number: US3701483A
Application number: US61245A
Authority: US
Inventors: Robert C Crosby; John D Holley
Original assignee: Marmon Group Inc
Current assignee: Marmon Group Inc
Priority date: 1970-08-05
Filing date: 1970-08-05
Publication date: 1972-10-31
Anticipated expiration: 1989-10-31
Also published as: CA927719A

Abstract

An apparatus for reducing wood elements such as railroad ties into preselected size shreds. The apparatus includes tearing means arranged for separating metal inclusions from the wood elements without substantially affecting the wood-tearing ability of the wood-tearing means. The apparatus is adapted to be moved on a conventional railroad track to a tie disintegrating site and is arranged to discharge the shredded wood fibers adjacent the railroad track.

Description

United States Patent [151 3,701,483 Crosby et a1. 511 Oct. 31, 1972 [54] RAILROAD TIE SHREDDER 3,128,054 4/1964 Bei1er..- ..241/186 R [72] Inventors: Robert Crosby, Knoxville, Tenn-J 3,481,235 12/1969 Kaufman et a1 ..241/32 X John D. Honey Montgomery Ala 3,486,704 12/1969 Persky ..241/186 R X 150,932 5/1874 Barker ..241/280 [73] Assignee: The Marmon Group, Inc. 3,132,815 5/1964 Wagner ..241/277 [22] Filed, 5 1970 3,153,511 10/1964 Atack et a1. ..241/277 [21] Appl. No.: 61,245 I Primary Examiner-Granville Y. Custer, Jr.

Attorney-Hofgren, Wegner, Allen, Stellman & Mcs2 U.S. Cl'. ..241/32, 241/34, 241/186 R,

v 241/190, 241/280 57 ABSTRACT [51] Int. Cl. ..B02c 13/31 1 581 Field of Search ..241/28, 32, 33, 34, 64, 186, An pp a for d g p elements such as l- 241/189, 190,223, 277 280 road ties into preselected size shreds. The apparatus includes tearing means arranged for separating metal inclusions from the wood elements without substan- [56] References cited tially afiecting the wood-tearing ability of the wood- UNITED STATES PATENTS tearing'means. The apparatus is adapted to be moved on a conventional railroad track to a tie disintegrating 2,839,254 6/1958 Smith ..241/190 X site and is arranged to discharge the shredded wood 3,559,898 2/1971 Rlllkfi ..24.1/172 X fibers adjacent the railroad track. 1,864,973 6/1932 Buchanan ..241/189 R 3,101,759 8/1963 Sterner et a1 ..241/186 R X 25 Claims, 5 Drawing Figures PATENTEDBBT31 m2 3.701.483

sum 1 OF 3 4 &

mvsmon @ZeW Z' Gmafiy ATTORNEYS RAILROAD. TIE smmuunn BACKGROUND OF THE INVENTION sequent disposal. Such hogging devices have the serious disadvantage of requiring substantial maintenance of the sharp knife portions thereof. A particularlyserious problem arises in the use of such hogging devices in connection with breaking up railroad ties and the like in that metal inclusions in the tie, such as broken portions of spikes, etc., seriously damage the knife portions of the hogging devices when encountered in the ties, thereby aggravating the high maintenance requirement problem.

SUMMARY OF THE INVENTION The present invention comprehends an improved apparatus for reducing wood elements such as railroad ties into preselected size shreds eliminating ,thedisadvantages of the above discussed known apparatuses.

More specifically, the invention comprehends an apparatus having means for holding a wood element to be shredded, means for tearing a first exposed predetermined depth surface portion of the supported wood element, and means for progressively feeding the wood element to present at least one further exposed surface portion of the torn wood element to the tearing means for tearing the same thereby totear the element substantially fully to shreds.

The wood element may comprisea railroad tie which may have random metal inclusions therein such as broken metal spikes and the like. The tearing means of the apparatus comprises cutter bits arranged for separating such metal inclusions from the wood elements without substantially affecting the wood-tearing ability of the tearing means.

The apparatus further includes means for breaking the torn portions into shortened lengths comprising a plurality of cutter bits acting in opposition to the cutter bits tearing the shreds from the tie. The ties may be carried on a yieldable support adapted to guide the progressively narrowing wood elements into operative association with the cutter bits. More specifically, the apparatus may be arranged to provide a concurrent shredding of a plurality of ties.

The apparatus may include a conveyor for delivering the torn shreds to a preselected discharge zone. Further, conveying means may be provided for transferring the ties from piles thereof to the tearing means. The conveyor may be arranged to be stalled. while applying driving force against the wood elements being shredded and permit a successive delivery of unshredded ties to the shreddingmeans upon completion of the shredding of previously delivered ties.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a fragmentary side elevation of an apparatus for reducing wood elements into preselected size shreds, embodying the invention;

FIG. 2 is an enlarged transverse vertical section of the apparatus taken substantially :along the line2-.2 of

FIG. 1;

FIG. 3 is a vertical section taken substantially along the line 3-3 of FIG. 2;

FIG. 4 is an elevation of a cutter bitand mounting means as carried on the driving drum; and

FIG. 5 is a side elevation thereof.

In the exemplary embodiment of the invention as disclosed in the drawing, an apparatus generally designated 10 is shown to comprise means for reducing wood elements such as railroad ties ll'which may comprise full length ties or cut ties, into preselected size shreds 12. The apparatus includes tearing means generally designated 13 which not only serve to tear the ties into wood fiber shreds, .but also act to separate from the ties metal inclusions, such as metal spike dead heads 14, without substantially adversely affecting the wood-tearing ability of the tearing means 13. As shown in FIGS. 3, 4, and 5, the wood-tearing means may comprise a plurality of cutter bits 15 carried on a rotating drum 16 to engage the upper surface 17 of the ties, to tear the shreds l2 therefrom, with. successive ties being correspondingly reduced in height until the entire cross-section of the tie is shredded. The apparatus further includes conveyor means generally designated 18 for feeding the ties into operative association with the tearing means 13. The ties are maintained in such association by means of a resiliently urged carrier 19 subjacent drum 16 bringing the upper surface 17 of the ties into the desired tearing association with tearing means 13.

As shown in FIG. 1, apparatus 10 may comprise a self-contained unit having a frame 20 carried on suitable wheels 21 which may comprise railway wheels adapted to movably carry the apparatus on conventional railroad tracks 22 to a preselected site for the tie shredding operation. The apparatus may be selfprope'lled by means of a suitable drive generally designated 23 which may comprise a conventional engine-hydraulic pump drive and a conventional multispeed, herein three-speed, hydraulic motor drive generally designated 24 connected to the wheels by a conventional differential 25. Drive 23 includes an output drive means 26 for driving a sprocket 27 from a planetary axle 28 carried on a support 29 on frame 20. Drum 16 is carried on a shaft 30 rotatably joumalled in bearings 31 carried on supports 32 mounted on frame 20 at the opposite sides of the apparatus. Also coaxially secured to shaft 30 is a pair of drum sprockets 33 which are driven by a suitable chain 34 from drive sprocket 27. A protective enclosure 35 may be provided extending partially around the drum.

As indicated briefly above, ties may be delivered to apparatus 10 from adjacent the railroad tracks 22 by means of feed conveyor 18. The conveyor is swingably mounted a side plate carried on supports 32 by means of a pivot mounting 36 under the control of a piston device 37 connected between frame 20 and the conveyor. Piston device 37 is arranged to swing the conveyor to a lowermost loading position as shown in FIG. 1 wherein the forward end 38 of the conveyor is disposed substantially at rail level. The forward end of the conveyor may be provided with a pair of supporting rollers 39 adapted to engage the track 22 for supporting the distal end of the conveyor in the loading operation. The conveyor may include a plurality of dogs 40 for moving the ties upwardly to the shredding position on carrier 19 and may be provided at its lower end with a loading tray apparatus 41 adapted to dump the ties onto the conveyor in the loading operation. Tilting of the loading tray may be effected by a suitable piston device 42 connected between the loading tray and the conveyor, as seen in FIG. 1.

Referring now more specifically to FIGS. 2 and 3, carrier 19 is shown to comprise a table having an arcuate upper plate 43 onto which the ties 17 are delivered from conveyor 18. The carrier is pivotally mounted by means of pivot 36 on the frame side support 32. As shown in FIG. 3, conveyor 18 may be driven by means of a suitable drive 44 adjacent pivot 36. Drive 44 illustratively comprises a conventional hydraulic motor drive driven from said engine hydraulic pump drive 23 permitting said conveyor 18 to be stalled while applying driving force against said wood elements held by the holding means. Carrier 19 is swingably adjustably positioned relative to pivot 36 by means of a hydraulic piston device 45 connected between frame 20 and a distal end portion 46 of the carrier. Piston'device 45 may be manually controlled to retract the carrier downwardly permitting facilitated delivery of the ties to between the carrier and the drum as at start-up of the operation. The piston device may comprise a conventional piston device applying a preselected pressure to the carrier for optimum shredding operation by the tearing means 13.

As shown in FIG. 3, the leading tie 11' is of relatively low thickness having been substantially completely shredded in being fed to the forwardmost shredding position against a back-up anvil 47 which resultingly holds the entire series of ties on the carrier plate 43 in position to be shredded by the tearing means 13 on the rotating drum 16. More specifically, the arcuate plate 43 defines with the cylindrical periphery of the drum 16 a space 48 narrowing toward the anvil 47. Piston device 45 maintains the upper surfaces 17 of the ties 11 in operative position relative to the tearing means 13 by swinging the carrier in a counterclockwise direction, as seen in FIG. 3, as the tie heights decrease as a result of the tearing of the fibers from the upper surfaces thereof.

Anvil 47 is urged into operative position, as seen in FIG. 3, by means of a hydraulic piston device 49 connected between frame support 32 and an arm 50 carrying at one end the back-up anvil and pivotally mounted at its opposite end to the frame by means of a pivot 51.

A fail-safe solenoid 52 may be mounted on frame 32 and actuated by a cam 53 movable with anvil arm 50 for releasing the anvil and carrier in the event of a jam up.

As best seen in FIG. 2, drum 16 is provided with a plurality of tearing means 13 spaced both circumferentially about and parallel to the axis of the drum. Each device 13 includes a mounting block 54 secured to the drum 16 as by welding and a retainer 55 secured to the block 54 by suitable means, such as bolts 56 and nuts 57. Thus, when desired, cutter bit 15 may be readily replaced by loosening of the bolts 56. As shown in FIG. 2, the retainers 55 define between themselves a plurality of chip spaces 58 for receiving the torn shreds from the ties. The cutter bits may comprise conventional cutter bits conventionally available in the mining industry as used on chain cutter means. The bits are arranged to project radially outwardly beyond the outer surface of the retainers 55 approximately 5/ 16 inch whereby a bite of approximately 5/16 inch is effected by each cutter bit in engaging the upper surfaces 17 of the ties. Illustratively, the outer tip of the bits may be disposed at a radius of approximately two feet from the axis 59 of drum 16 where the drum is driven at a speed of approximately 60 rpm to effect an efficient high speed tie disintegrating operation.

As discussed above, the ties are retained against forward movement along carrier 19 by anvil 47 until such time as the forwardmost tie 11 is completely disin tegrated whereupon the series of ties on carrier 19 are automatically urged forwardly by conveyor 18 to bring the next forwardmost tie into abutment with anvil 47. Thus, a progressive shredding of the ties is effected automatically. As the lead tie 11 is reduced to its final size, the last shredding operation is effected by a movement of the tearing means cutter bits 15 in between a plurality of opposing cutter bits 60 defining the portion on anvil 47 against which the ties abut. Thus, the final shredding operation is one wherein the ties are broken between the cutter bits 60 by the rapidly moving cutter bits 15 with the cutter bits 60 projecting to their max imum extent inwardly between the cutter bits 15. Cutter bits 60 may be removably secured to anvil 47 by suitable means such as bolts 61 permitting facilitated replacement of the anvil cutter bits as desired. Cutter bits 60 may be similar to cutter bits 15.

Piston 49 is arranged to be substantially immediately released by solenoid 52 under high pressure such as by a wedging against anvil means 47 of a large nonshreddable element, such as a track tie plate, which may accidentally have been fed into the apparatus with the ties. As discussed briefly above, operation of the fail-safe solenoid 52 further immediately releases piston device 45 to release the carrier 19 and also may substantially immediately stop the apparatus to thereby minimize possible damage thereto. To effect a rapid stopping of the apparatus, a pair of brakes 62 may be provided at the drive to sprocket 27 to be operated substantially instantaneously by solenoid 52. At the same time, solenoid 52 may release a clutch 63 connected between the diesel engine hydraulic pump drive 23 and apparatus 10 thereby to correspondingly substantially instantaneously discontinue driving of the drum.

Thus, in operation, when it is desired to disintegrate a group of railroad ties, which as discussed above may comprise full length ties or shortened tie lengths as previously removed from the track bed, apparatus 10 is brought to the site on tracks 22 by suitable operation of the wheel drive 24 with conveyor 18 raised to a track clearing disposition. Upon reaching the site, conveyor 18 is swung to the loading position of FIG. 1 and the tie elements to be disintegrated placed in loading tray 41. The loading tray is then pivoted to deliver the ties onto conveyor 18 which delivers the ties in turn onto the 27, 34, 33. Piston device 45 is then actuated to swing the carrier upwardly to urge the ties into operative association with the tearing means 13 carried on drum 16. The movement of "the cutter bits 15 of tearing means 13 across the upper surfaces 17 of ties 11 in space 48 causes portions of the upper tie surfaces to be torn therefrom and delivered through the comb-like arrangement of the opposing cutter bits 60 on anvil 47 as desired. In the illustrated embodiment, a discharge conveyor 65 may be mounted on frame 20 to receive the shredded fibers 12 and convey them away from the apparatus such as to adjacent the tracks 22 on the railroad right-of-way. Conveyor 65 may include a suitable hydraulic drive motor 66 and may utilize a conventional belt 67 as desired.

Should the cutter bits 15 engage a metal inclusion in a tie, such as a portion of a spike inadvertently remaining in the tie, the bits merely dig the metal inclusion outwardly from surface 17 and deliver it with the shredded fibers 12 past the anvil bits 60. In operation, it has been found that such metal inclusions are merely weakly thrown from the apparatus with the shredded fibers 12. When all of the leading tie becomes fully disintegrated, conveyor 18 acts to continually urge the se ries of ties forwardly in a step-by-step type of advance so the next succeeding tie becomes the leading tie and is subsequently fully disintegrated at the lead position.

The last group of ties to be disintegrated is urged to the final position by the rotary motion of the tearing means in the absence of any urging action of conveyor 18 at this time. Any sudden change in the position of the carrier necessary to accommodate the progressive movements of the ties such as at the completion of dis integration of the leading tie is readily accommodated by the yieldable piston means 45. As discussed above, should the apparatus jam for any reason such as by an accidentally included tie plate or other relatively large metal object, the fail-safe solenoid 52 immediately ,effects stoppage of the apparatus permitting the jamming element to be removed. In restarting the apparatus, piston 45 may space the ties from the drum 16 to facilitate start-up and subsequently bring the ties into operative relationship with the tearing means 13 after the drum is brought to speed.

Upon completion of the tie disintegrating operation, conveyor 18 and loading tray 41 are restored to the raised position, permitting the apparatus to be moved on tracks 22 as desired by means of the self-contained drive.

As the cutter bits 15 do not rely on a maintained knifelike sharpness to effect the "shredding operation, occasional encounters with metal inclusions such as railroad spikes and the like do not seriously affect the action of the cutter bits in effecting the disintegration of the ties. Thus, the apparatus has a long maintenancefree life while yet providing highly efficient complete disintegration of the old ties at the site eliminating the need for costly movement of the ties to remote disposal areas and avoiding serious problems such as pollution of the atmosphere as where such ties have heretofore been burned upon removal from the tracks.

The invention has been described in connection with a disintegrating apparatus which may be mobile for effecting the shredding operation in situ. As will be obvious to those skilled in the art, the apparatus may alternatively comprise a stationary apparatus to which the element to be disintegrated may be brought within the scope of the invention. 1

The foregoingdisclosure of specific embodiments is illustrative of the broad inventive concepts comprehended by the invention.

We claim:

1. Apparatus for reducing fibrous wood elements which may have random meta] inclusions therein into preselected size shreds, comprising: holding means for holding a fibrous wood element to be shredded having the fibers thereof extending generally parallel; tearing means for tearing free substantially without cutting a first exposed predetermined depth surface fiber portion of the supported wood element; and feeding means for progressively feeding the wood element to present at least one further exposed fibrous surface portion of the torn wood element to the tearing means for tearing the samethereby to tear the fibers successively from the element and reduce the element substantially fully to shreds and tearing said metal inclusions free from the wood elements without substantially adversely affecting the fiber tearing ability of said tearing'means.

2. Apparatus for reducing wood elements into I preselected size shreds, comprising: holding means comprising cutter bits for holding a fibrous wood element to be shredded; means for tearing a first exposed predetermined depth surface fiber portion of the supported wood element; and means for progressively feeding the wood element to present at least one further exposed fibrous surface portion of the torn wood element to the tearing means for tearing the same thereby to tear the fibers successively from the element and reduce the element substantially fully to shreds.

3. Apparatus for reducing wood elements into preselected size shreds, comprising: means for holding a fibrous wood element to be shredded; means for tearing a first exposed predetermined depth surface fiber portion of the supported wood element; and means for progressively feeding the wood element to present at least one further exposed fibrous surface portion of the torn wood element to the tearing means for tearing the same thereby to tear the fibers successively from the element and reduce the element substantially fully to shreds, said holding means comprising means for dividing the final surface portion of the wood elements into shortened lengths.

4. The apparatus of claim 1 wherein said feeding means comprises a support, and means for yieldably urging the support toward the tearing means to urge wood elements disposed there-between into tearable association with the tearing means.

5. The apparatus of claim 4 wherein said support defines with said tearing means a narrowing wood element receiving space adapted to receive in the progressively narrow portions thereof the progressively smaller wood elements resulting from the progressive removal of said surface portionstherefrom.

6. Apparatus for reducing wood elements into preselected size shreds, comprising: means for holding a fibrous wood element to be shredded; means for tearing a first exposed predetermined depth surface fiber portion of the supported wood element; and means for progressively feeding the wood element to present at least one further exposed fibrous surface portion of the torn wood element to the tearing means for tearing the same thereby to tear the fibers successively from the element and reduce the element substantially fully to shreds, said tearing means including means defining spaces for receiving said torn surface portions and said tearing means further defining means for transferring said torn surface portions from said spaces to a discharge zone for delivering said torn surface portion from the apparatus.

7. The apparatus of claim I wherein said tearing means comprises a cylindrical base, a plurality of tearing bits having elongated tearing tips, and means for securing said bits to said base to project outwardly therefrom with the tips extending generally parallel to the elongate extent of the fibers of said wood elements.

8. Apparatus for reducing wood elements into preselected size shreds, comprising: means for holding a fibrous wood element to be shredded; means for tearing a first exposed predetermined depth surface fiber portion of the supported wood element; and means for progressively feeding the wood element to present at least one further exposed fibrous surface portion of the torn wood element to the tearing means for tearing the same thereby to tear the fibers successively from the element and reduce the element substantially fully to shreds, said tearing means comprising a cylindrical base, a plurality of tearing bits, and means for securing said bits to said base to project outwardly therefrom and comprising means fixedly on said base, and means cooperating with said mounting means for adjustably securing said bits thereto to provide selective control of the depth of tearing of said surface portions.

9. Apparatus for reducing wood elements into preselected size shreds, comprising: means for holding a fibrous wood element to be shredded; means for tearing a first exposed predetermined depth surface fiber portion of the supported wood element; and means for progressively feeding the wood element to present at least one further exposed fibrous surface portion of the torn wood element to the tearing means for tearing the same thereby to tear the fibers successively from the element and reduce the element substantially fully to shreds, said tearing means comprising adjustable means for providing selectively different depths of tearing of said wood element surface portions.

10. The apparatus of claim 1 wherein said apparatus further-includes means for conveying the torn surface portions to a preselected discharge space and a single power means for driving said tearing means and said conveying means.

11. The apparatus of claim 1 wherein said apparatus further includes railway wheel carriage means for facilitated transport of the apparatus as desired.

12. The apparatus of claim 1 wherein said holding means comprises means for holding a plurality of said wood elements and said tearing means comprises means for concurrently tearing surface portions of each of said plurality of held wood elements.

13. The apparatus of claim 1 wherein said feeding means comprises a conveyor having spaced elements engaging respectively successive wood elements, and

means for driving said conveyor to urge said spaced elements toward said holding means, said driving means comprising impositive drive means permitting said conveyor to be stalled while applying driving force against said wood elements held by said holding means.

14. Apparatus for reducing wood elements into preselected size shreds, comprising: means for holding a fibrous wood element to be shredded; means for tearing a first exposed predetermined depth surface fiber portion of the supported wood element; and means for progressively feeding the wood element to present at least one further exposed fibrous surface portion of the torn wood element to the tearing means for tearing the same thereby to tear the fibers successively from the element and reduce the element substantially fully to shreds, said tearing means and said holdingmeans comprising similar bits.

15. Apparatus for reducing wood elements into preselected size shreds, comprising: means for holding a fibrous wood element to be shredded; means for tearing a first exposed predetermined depth surface fiber portion of the supported wood element; and means for progressively feeding the wood element to present at least one further exposed fibrous surface portion of the torn wood element to the tearing means for tearing the same thereby to tear the fibers successively from the element and reduce the element substantially fully to shreds, said holding means comprising a yieldable support and holding element carried on said support movably adjacent said tearing means.

16. The apparatus of claim 1 wherein said feeding means comprises a movable carrier adjacent said tearing means and means for selectively spacing said carrier from said tearing means for inserting said wood elements therebetween to initiate operation of the apparatus.

17. The apparatus of claim 16 including means for pivotally mounting said carrier to swing selectively toward and from said tearing means.

18. The apparatus of claim 16 wherein said tearing means comprises a plurality of tearing bits and means for moving said bits in an annular path extending a preselected distance with said wood element surface portion.

19. The apparatus of claim 18 further including means for pivotally mounting said carrier to swing about an axis spaced outwardly from said annular path and with a portion of the carrier spaced from said axis juxtaposed to said annular path to dispose said wood element surface portion generally tangential to said annular path.

20. The apparatus of claim 1 wherein said apparatus includes means for concurrently braking the tearing means and discontinuing the drive thereof in the event of a jam-up of the apparatus.

21. Apparatus for disintegrating used wood railway ties having randomly disposed metal inclusions such as spikes therein, said apparatus comprising: holding means for holding a railway tie element and a first portion thereof; and tearing means for progressively tearing free substantially without cutting wood fibers from a surface portion of the tie element spaced from the held portion, said tearing means further comprising means for freeing said metal inclusions from said tie elements without substantial damage to said tearing 24. The tie disintegrating apparatus of claim 21 further including means for causing the holding means to space the tie element from the tearing means substantially immediately upon a jamming of the tearing means.

25. The tie disintegrating apparatus of claim 24 further including means for substantially immediately stopping the operation of the tearing means as a result of said jamming. v

Claims

1. Apparatus for reducing fibrous wood elements which may have random metal inclusions therein into preselected size shreds, comprising: holding means for holding a fibrous wood element to be shredded having the fibers thereof extending generally parallel; tearing means for tearing free substantially without cutting a first exposed predetermined depth surface fiber portion of the supported wood element; and feeding means for progressively feeding the wood element to present at least one further exposed fibrous surface portion of the torn wood element to the tearing means for tearing the same thereby to tear the fibers successively from the element and reduce the element substantially fully to shreds and tearing said metal inclusions free from the wood elements without substantially adversely affecting the fiber tearing ability of said tearing means.

2. Apparatus for reducing wood elements into preselected size shreds, comprising: holding means comprising cutter bits for holding a fibrous wood element to be shredded; means for tearing a first exposed predetermined depth surface fiber portion of the supported wood element; and means for progressively feeding the wood element to present at least one further exposed fibrous surface portion of the torn wood element to the tearing means for tearing the same thereby to tear the fibers successively from the element and reduce the element substantially fully to shreds.

5. The apparatus of claim 4 wherein said support defines with said tearing means a narrowing wood element receiving space adapted to receive in the progressively narrow portions thereof the progressively smaller wood elements resulting from the progressive removal of said surface portions therefrom.

7. The apparatus of claim 1 wherein said tearing means comprises a cylindrical base, a plurality of tearing bits having elongated tearing tips, and means for securing said bits to said base to project outwardly therefrom with the tips extending generally parallel to the elongate extent of the fibers of said wood elements.

10. The apparatus of claim 1 wherein said apparatus further includes means for conveying the torn surface portions to a preselected discharge space and a single power means for driving said tearing means and said conveyiNg means.

13. The apparatus of claim 1 wherein said feeding means comprises a conveyor having spaced elements engaging respectively successive wood elements, and means for driving said conveyor to urge said spaced elements toward said holding means, said driving means comprising impositive drive means permitting said conveyor to be stalled while applying driving force against said wood elements held by said holding means.

14. Apparatus for reducing wood elements into preselected size shreds, comprising: means for holding a fibrous wood element to be shredded; means for tearing a first exposed predetermined depth surface fiber portion of the supported wood element; and means for progressively feeding the wood element to present at least one further exposed fibrous surface portion of the torn wood element to the tearing means for tearing the same thereby to tear the fibers successively from the element and reduce the element substantially fully to shreds, said tearing means and said holding means comprising similar bits.

21. Apparatus for disintegrating used wood railway ties having randomly disposed metal inclusions such as spikes therein, said apparatus comprising: holding means for holding a railway tie element and a first portion thereof; and tearing means for progressively tearing free substantially without cutting wood fibers from a surface portion of the tie element spaced from the held portion, said tearing means further comprising means for freeing said metal inclusions from said tie elements without substantial damage to said tearing means and providing for disintegration of the entire tie element by said progressive tearing thereof.

22. The tie disintegrating apparatus of claim 21 further including carriage means provided with railway wheels for movement oF the apparatus along a railway track for disintegrating said tie elements at the site of removal of the ties.

23. The tie disintegrating apparatus of claim 21 further including means for delivering the disintegrated tie material onto the adjacent ground for facilitated natural conversion to humus.

24. The tie disintegrating apparatus of claim 21 further including means for causing the holding means to space the tie element from the tearing means substantially immediately upon a jamming of the tearing means.

25. The tie disintegrating apparatus of claim 24 further including means for substantially immediately stopping the operation of the tearing means as a result of said jamming.