US2688349A - Log barking machine of light frame and having safety means for holding the log - Google Patents

Description

' Sept. 7, 1954 LOG BARKING MACHINE OF LIGHT FRAME AND HAVING SAFETY MEANS FOR HOLDING THE LOG Filed Feb. 17, 1950 l T. w. NICHOLSON 2,688,349

4 Sheets-Sheet l Iwo/w45 nf /V/mawom YM "gf/@V tt arneys Sept. 7, 1954 I T. w. NICHOLSON LoG BANKING v2,688,349 MACHINE 0E LIGHT FRAME AND HAVING SAFETY MEANS FOR HOLDING 'IHE LOG 4 ASheets-Sheet 2 Filed Feb. 17, 1950 THOMAS n( /v/cHoL sfo/v IN VEN TOR.

Sept. 7, 1954 LOG BARKING MACHINE OF LIGHT FRAME AND HAVING Filed Feb. 17, 1950 T. w. NlcHoLsoN 2,688,349

SAFETY MEANS FOR HOLDING THE LOG 4 Sheets-Sheet 3 THOMAS W N/CHLSON INVENTOR.

Sept. 7 1954 T. w, NICHOLSON 2,688,349

' LOG BARKING MACHINE OF LIGHT FRAME AND HAVING SAFETY MEANS FOR HOLDING THE LOG Filed Feb. 17. 1950 4 Sheets-Sheet .4

x? 7' TOR/VE YS Patented Sept. 7, 1954 LOG BARKING 'MACHINE 0F LIGHT FRAME AND HAVING SAFETY MEANS FIOR HOLD'- ING THE LOG Thomas W. Nicholson,` Seattle, Wash.

Application February 17, 1950, Serial No. 1443676 Claims. l

My inventionrelates to the art of mechanical log barking machines.

More particularly my invention relates to a log debarking machine characterized byv having a 'relatively light frame relative to the `forces developed-said. lightness of the frame being made possible by the novel construction provided by my invention, and also characterized by having auknife resiliently held against a rotating log., which knife is pivotally mounted so that it is angularly movable longitudinally of the log.

Also, particularly is my invention characterized by having a bark cuttingv means operable to cutthe bark circumferentially of the log in conjunction and preferably substantially simultaneously with the bark removing knife. My invention is also characterized by provi-ding for a log to be resiliently held in rotating chucks whereby when debarking stresses become too great, the log will be freed from the machine. f

In preparing logs for the manufacture of veneer and for the manufacture of pulp, itis necessary that the bark be removed, which bark may vary in thickness from 2" to 4 and even more.

Mechanical barking machines have heretofore been of somewhat limited application due to the great weight of machines prior to4 mine. A pri- -mary object of my invention is to overcome this disadvantage bya functional arrangement of the `elements of a barking machine resulting in the- Aelimination of a substantialpart of the Weight or mass heretofore characteristic of such machines.

In machines of the character described as `heretofore commonly constructed, difficulty has been encountered due toy the digging in of the knife resulting in jamming of the machine and often consequent damage to expensive components of the machine. Another primary object of my invention has( been to mount the knife so as to minimize the danger of such` digging in and to provide safety features `resulting infthe automatic release of the log where such digging in cannot be overcome.

A further difficulty heretofore encountered in the operation of mechanical barking machines has been in the removal of stringy bark, that is, bark containing long fibers Whichcause adherence of a long section of bark tothe log in resistance to the knife. My invention includes the discovery that by said cutting or sawing of the bark circumferentially that the knife operates to rremove very substantially all of the stringy portions of the bark that have heretofore been left on the log.

(Cl. LPL-208) Furthermore, cutting of such bark into: segments facilitates handling by conveyormeans `and in bark'utilization processes after removal from the vlog and thereby overcomes the problem heretofore existent in connection with disposal of such bark.

Also, in` mechanical'. barking devices heretofore employed', diiiiculty` has been encountered in removing the bark surrounding knots, depressions and other irregularities. in theA surface of the log. A primary object of my invention hasbeen to provide thev functional. combination of knife and cutter head such that the cutter head can be selectively used to remove such knotsV and other irregularities from the surface of the log which could notv be' removed by the debarking knife and from which irregularities the knife cannotremove the bark.

Stresses developed in removing the bark of proportions above-mentioned are very great and it is an object of my invention to bring about a counteracting. of the. forces developed in such operation to' have them nullify each other as far as possible and. therefore provide for the use of relatively light frame members in novelfarrangement.

Furthermore, a primary object of my invention is to provide for a chuck urged against the end of a log by fluid pressure means vsuch that when forces greater thana predetermined magnitude develop, thelog isv freed from the machine thereby preventingv jamming and damage to the machine.

Another primary object of my invention is to resiliently hold the knife against the log with operative pressure of a predetermined magnitude so` that rotational stresses exceeding this magnitude will cause the knife to pivotally yield and thereby prevent jamming of the machine. Preferably this is done with two iiuid pressure means-one providing for a forcing back of the pivotally mounted tool arm, and the other providing for pivotal or rotational yielding directly of the knife holding member which is mounted on said tool arm.

The above-mentioned general objects of my invention, together with others inherent in the same, are attained by the mechanism illustrated in the following drawings, throughout which drawings like reference numerals indicate like parts:

Figure 1 is a View in front elevation of the preferred form of my invention;

Fig. 2 is-aview in end elevation of the machine illustrated in Fig. 1;

Fig. 3 is an enlarged plan view of the knife holding member or knife yoke and knife;

Fig. 4 is a View in side elevation of the knife yoke or knife holding member and knife illustrated in Fig. 3;

Fig. 5 is a view in side elevation of a modified knife yoke or knife holding member and knife provided with a cutter head;

Fig. 6 is a plan View of the same construction as illustrated in Fig. 5; and

Fig. 'I is a view in perspective of a modified form of my invention.

My improvement in barking machine frames can best be illustrated by reference to Figs. l and 2.

Drive pedestal I0 is made up of back plate I2 and front plate I3 interconnected by end plate I4 and side plate I5. Plates I2, I3, I4 and I5 carry drive spindle bearing sleeve I6 which provides bearing surface for drive spindle I1.

Likewise, chucking pedestal I8 is similarly formed of back plate I9 (see Figure 7), front plate 20, end plate 2I, and side plate 22. Chucking pedestal I8 carries a bearing sleeve 23 which provides bearing surface for a piston rod 24a. The idler chuck 24 is rotatably connected with the piston rod 24a of cylinder 25, which cylinder 25 may be pneumatically or hydraulically operated. However, for this purpose I have found a pneumatically operated cylinder the more desirable.

Inasmuch as the cylinder and piston construction are of conventional and well-known design, details of said cylinder and piston are neither illustrated nor included in the specification.

Drive pedestal I0 is supported by parallel base beams 26 and 21. Chucking pedestal I8 is supported by parallel base beams 28 and 29.

Longitudinal support member 30 is connected at right angles with base beams 21 and 29. This longitudinal support member 39 is in cross-section inclined transversely to a vertical plane passing through the longitudinal axis of the chucks. It is thus ideally located to take the stress and shock caused by the fall of a log released from the chucking spindle I1 and the chuck 24. Such shock is transmitted along the lateral axis of the longitudinal support member 39.

The carriage track may be preferably formed of track channel members 3l and 32 suitably connected with pedestal front plates I3 and 20 as by welding and connected as by welding to the end portions of base beams 21 and 29. Channel members 3| and 32 are in cross-section inclined toward the vertical plane, through the longitudinal axis of the chucks.

Carriage 33 is carried by the angularly disposed track channel members 3I and 32 whereby the stress developed by the contact of the knife 34 with the log engaged in the machine and rotating counterclockwise with respect to Fig. 2, is resolved into counteracting forces directed substantially in the direction of the axis of the chucks. The carriage 33 is slidably mounted on said tracks 64 and 65 by means of roller chain means 6I and 62, segments of which are illustrated in Fig. 1. The chains are ldriven by conventional power means, as an electric motor, of standard and conventional design (not shown).

Bark deflector plate 35 runs longitudinally of the machine between drive pedestal I9 and chucking pedestal I8 and is connected with longitudinal support channel 30 and with pedestal front plates I3 and 20 and with track channel member 3|.

Tool arm 36 is pivotally mounted on carriage 33 by means of shaft 31 carried by tool arm base brackets 38 and 39.

Pivotal movement of tool arm 36 is governed by piston arm 40 of cylinder 4I, which cylinder 4I is pivotally mounted on cylinder base brackets 42 and 43 by means of shaft 44. Cylinder base brackets 42 and 43 are carried by the lower portions of the carriage 33.

Cylinder 4I may be either pneumatically or hydraulically operated. However, I have found a pneumatically operated cylinder best for this particular purpose because of the greater compressibility of air as compared to liquid and the consequent resiliency imparted to the tool arm 36 as it holds the knife 34 against the surface of a log being debarked.

'Ihe tool arm 36 is connected to piston arm 46 by means of shaft 10.

Knife yoke or knife holding means 45 pivots on shaft 46. Pivotal movement of knife yoke 45 on shaft 46 is governed by piston arm 41 on cylinder 48, which cylinder may be of either hydraulic or pneumatic operation. Cylinder 48 is pivotally mounted on tool arm 36 by means of shaft 49. This construction permits not only the tool arm 36 to be moved toward and away from a log engaged in the machine by means of cylinder 4l and piston arm 40, but also permits of a supplementary movement of knife 34 toward and away from the surface of the log by means of piston 48 and piston arm 41 independently of tool arm 36. The angle of the knife with respect to the log can therefore be controlled.

Referring now to Figs. 3 and 4, knife 34 is angularly movably mounted in the knife holding member 45 preferably by a pin 50. The angular movement of the knife 34 is limited by the contact of the butt of the knife 34 and the wall of the slot in knife holding member 45 in which the knife is held by pin 50. I have found a fifteen degree angular movement of the knife to be satisfactory.

The end of piston arm 41 forms a bearing sleeve 5I which surrounds shaft 52 thereby connecting piston arm 41 with knife holding member 45.

Saws 53 and 54 may be rotatively mounted on shafts 55 and 56 and driven through belts 51 and 58 by an electric motor mounted on tool arm 36. The motor is of conventional type and design and is therefore neither illustrated nor described.

The modified form of knife holding member 45 is illustrated in Figs. 5 and 6 in which form a cutter head 59 is mounted on shaft 60 of tool arm 36 and driven by an electric motor as heretofore described in connection with the driving of saws 53 and 54.

In the modification of my invention illustrated in Fig. 7, the tool arm 66 is pivotally mounted to the carriage 33 by means of shaft 12 carried in tool arm base bracket 13.

The knife 34 (the knife being of a blunt end form) is angularly movably mounted in the upper portion of tool arm 66.

Tool arm 66 is resiliently urged toward the surface of the log to be debarked by means of cylinder 4I and piston arm 40, which arm 4U is carried by shaft 19.

Pedestals I0 and I8 as well as track 61 are mounted on base beams 68 and 69.

The carriage 33 is slidably movable on track 61 by means of carriage roller chains 6I and 62 driven by conventional power means, as an electric motor (not shown),

Mode of. .Operation i1 4The rnode of operation of, my invention is as follows:

.A los ishoistedor otherwise conveyed to a position between @buckingspindle Il andrthefehuek 2 4 so that the axis of. the los approximates the axis of rotation ofthe 4ehutliinespindle ,I Land the ,chuck 24.

F1uid nressurewithin `the cylinder 251s, v then increased thus .driving the chuck 24 intotheend of the los, and terrine. the. Ice aeainst the. drive Spindle Il., Spindle l1 is then rotated by means of forceapplied as by anelectremotor through rollerehain 63.

The carriage 33 carrying the tool arm 3 6 may bet-slidably; meyedby means of carriage roller chai s Bland lizluntileppeeiteene end por-tien of the. 10s.

.The welarm Wismar be swung` into contact with thex les by means ot fluid pressure increase ineylnder 4l and consequent, Outward movement @fristen arm 4i! as respeetsthe eylinder 4l. The angle .of `the knife blade may beadjusted .by alteration of the ,fluidr pressure in cylinder 48 and consequentmovement ofpiston arm 41 and thereby knife holder 45 tothedesirehangle withrespect to the barkvcovered surface o flthe log.

F l-Eihould it be expected--thatthe bark to be re- ,moved will give troublefdue to its stringy character, thesaws 53 `and 54 vmay be employed to makey peripheral circumferential` cuts inthe bark by appropriate l correlative y swinging movements ,ofthe knife .arm 45 and thetool arm 36 whereby the saws are placed linfoperative cutting position iagainst the surface of the log. Knife 34Lcan be adjusted independently of the saws 5 3 and 54 by means of cylinder 48 and piston arm 41 as described above.

In the modified form of knifeholderillustrated in Figs. 5 and 6, the cutter head 59 may be moved into operative position by movement of the tool `arm 35, the knife being substantially simultaneously removed from operative position by means .of piston 48.

The cutting edge of the knife 34 willtend to Lfollow the surface of the log despite irregulari- .ties in the. surfacey because of the-angular move- `ment ofthe knife 34. about the axis of the pin 5U, .the cutting edge, being rockable longitudinally of the long axis of thelog. Thus the knife edge has two adaptations to the surface of the logonezradially of the log, and one longitudinally thereof.

Since the rotation of the log is counterclock- Wise as shown in Fig. 2, that is, the log is turning upwardly against the knife 34, any force exerted by the log against the knife 34 in excess of that exerted by the fluid pressure within cylinder 4I or that within cylinder 48 will result in adaptation of the tool arm 36 as a unit or adaptation of knife holding member 45-the one permitting the tool arm 36 to swing backwardly from the log and the other permitting of a rotational adaptation of the knife with respect to the bark. Should the force of the log against the knife fail to overcome the pressure exerted by fiuid pressure means in cylinder 4i or cylinder 48 during jamming. the resiliency in the chuck 24 provided by reason 0f the fluid pressure means carried by cylinder 25 will result in the freeing of the log from the machine and thus eliminate the danger of damage to the machine as a result of such jamming.

Of course, the fluid pressure within cylinders 4|, 2.5.,and 48 A.may be' adjusted tothe ,desired magnitudes both absolutely and inwrelation to eachother. f Adjustable .relief Valves .are preferablyprovided on each cylinder so that if a counteracting. force of predetermined magnitude is., transmitted to the piston arm, the. arm'will automatically yield to such, pressure thus elimilnatingdanger of seriousrinjury to the machine due tojamming.

The carriage 33 `carrying the tool arm 36 is movable longitudinally ofthe frame ofv themachine and the log carried in the machine by means of power-driven. chains 6| and B2, segments oftwhichare shown attached to thecarriage inIig. 1.- The carriage driving mechanism is of -conventional designand since in the prefer-'red form of my invention it is identical with that shown in the modified lform in Fig. 7, it is not described herein or illustrated in detail.

In the event that the knife should dig into thebark to an extent that undue strains are developed, provisions have been made for stopping vther. rotation of the 10g to avoid what is called jamming The fact that the knife, for example 34, in my invention is pivotally mounted ony pin 50, soas topermit its limitedswinging inta plane which contains the longitudinal axis of the log, permits the knife toautomatically adjust itself so as to minimize the danger of jamming Also, the pivotalmounting of the knife in combination with the cylinder 48 providing for 4resilient operastion,tends to minimize jamming I have found that the knife courses along. the surface of the. rotating log yielding both laterally, and vertically to obstructions which in prior machines would result injamming.

- ,By. having the pressure cylinder 4| operating the tool arm and by having the pressure cylinder 48 operating the knife holding member 45, an

advantage is gained from the combination greater than the sum of those components derived from each separately. The overlapping pressures `exerted by the combination of the two cylinders `results in a more constant contact of the knife 34 with the surface of the log, although such contact is still a yielding or resilient one.

t Obviously, changes may be made in the forms, dimensions, and arrangement of the parts of my invention, Withoutvdeparting from the principle thereof, the above setting forth only preferred forms of embodiment.

1. In a` machine of the character described, a

frame vcomprising end pedestal members, a beam hayinga track mounted thereon and joining said pedestal members, said beam being transversely inclined to a vertical longitudinally disposed plane through the machine, and a longitudinal support beam joining said pedestals and disposed intermediate the base of said pedestals, said longitudinal support member being in transverse section inclined to said Vertical plane; chucking means mounted on the upper end portions of said pedestals, whereby a log to be barked may be rotatively held; driving means connected with one of said chucking means; and a tool carriage slidably mounted on said track, said tool carriage comprising a tool arm pivotally mounted thereon, pneumatic means pivotally carried by said carriage and pivotally connected to said tool arm, whereby said tool arm may be actuated toward the axis of rotation of said chucking means, knife holder means mounted on the upper portion of said tool arm, and a knife angularly movable in said knife holder means.

2. In a machine of the character described, a frame comprising end pedestal members, a beam having a track mounted thereon and joining said pedestal members, said beam being transversely inclined to a vertical longitudinally disposed plane through the machine, and a longitudinal support beam joining said pedestals and disposed intermediate the base of said pedestals, said longitudinal support member being in transverse section inclined to said vertical plane; chucking means mounted on the upper end portions of said pedestals, whereby a log to be barked may be rotatively held; driving means connected with one of said chucking means; fluid operated means connected with one of said chucking means which means is resiliently held by the pressure of said fluid during the debarking operation against the end of said log, whereby said chucking means may be applied to the end of a log andfunction as a safety means, whereby the development of rotational strains in excess of predetermined magnitude may be prevented; and a tool carriage slidably mounted on said track, said tool carriage comprising a tool arm pivotally mounted thereon. manually controlled pneumatic means pivotally carried by said carriage and pivotally connected to said tool arm, whereby said tool arm may be actuated toward the axis of rotation of said chucking means, knife holder means mounted on the upper portion of said tool arm, and a knife mounted in said knife holderv means.

3. In a machine of the character described, a frame comprising end pedestal members, a beam having a track mounted thereon and joining said pedestal members, said beam being transversely inclined to a vertical longitudinally disposed plane through the machine, a longitudinal support beam joining said pedestals and disposed intermediate the base of said pedestals, said longitudinal support member being in transverse section inclined to said vertical plane; chucking means mounted on the upper end portions of said pedestals, whereby a log to be barked may be rotatively held; a carriage slidably mounted on said track; a tool arm pivotally mounted on the upper portion of said carriage; knife holder means mounted on the upper portion of said tool arm; a knife disposed in said knife holder means and a fluid pressure means connecting said tool arm to the lower portion of said carriage, whereby a knife in said knife holder means may be held against a log being debarked and whereby any forces that may be developed by contact of the knife with the rotating log, are cushioned by said fluid pressure means, so that a relatively light l frame may be used.

4. In a machine of the character described, a

frame comprising end. pedestal members,l and a beam having a track mounted thereon and joining said pedestal members, said beam being transversely inclined to a vertically longitudinally disposed plane through the. machine; chucking means mounted on the upper end portions of said pedestals, whereby a log to be barked may be rotatively held; driving means connected with one of said chucking means; and a tool carriage slidably mounted on said track, said tool carriage comprising a tool arm pivotally mounted thereon, pneumatic means pivotally carried by said carriage and pivotally connected to said tool arm, whereby said tool arm may-be actuated towards the longitudinal axis of rotation of said log, knife -holder means mounted on the upper portion of said tool arm, and a knife mounted in said'knife holder means.

5. In a log barking machine the combination of a pivotally mounted tool arm; fluid pressure means connected with said tool arm whereby said tool arm may be resiliently actuated towards and away from the log being debarked in a. plane Vradially disposed with respect to the longitudinal axis of said log; a knife holding member having a knife mounting recess of rectangular form; a knife of rectangular form and less size mounted in said knife holding member recess by a pivot, the pivotal axis of which extends in a direction ysubstantially at right angles to the plane of the knife; and a chucking mechanism having a chucking spindle, pneumatic means automatically resiliently urging said spindle into a log and acting as a safety means while said log is being debarked, whereby when the strains develop upon the chucking means exceed a predetermined amount said pneumatic means operates as a safety means in releasing said log from the chucking means.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 198,327 Winn Dec. 18, 1877 871,296 Russell et al. Nov. 19, 1907 1,051,460 Simpson Jan. 28, 1913 2,328,545 Bukowsky Sept. 7, 1943 2,382,896 Medcoff Aug. 14, 1945 2,453,947 Swift Nov. 16, 1948 2,477,922 Emery et al. Aug. 2, 1949 2,576,967 Pauley et al. Dec. 4, 1951 FOREIGN PATENTS Number Country Date 522,701 Germany Apr. *13, 1931

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