US2774397A

US2774397A - Barking machine having feed roller power-driven at certain peripheral speed or log-driven at higher speed

Info

Publication number: US2774397A
Application number: US409912A
Authority: US
Inventors: Leffler Nils Gustav
Original assignee: Svenska Cellulosa AB
Current assignee: Svenska Cellulosa AB
Priority date: 1951-11-03
Filing date: 1954-02-12
Publication date: 1956-12-18
Anticipated expiration: 1973-12-18
Also published as: FR1070548A; US2855010A; DE938877C

Description

Dec. 18, 1956 N. e. LEFFLER 2,774,397

BARKING MACHINE HAVING FEED ROLLER POWER-DRIVEN AT CERTAIN PERIPHERAL SPEED OR LOG-DRIVEN AT HIGHER SPEED Original Filed Oct. 31, 1952 '2 Sheets-Sheet 1 M Hillllll L"; lllmlllll INVENTOR.

Pm, W 9 PM Dec. 18, 1956 G. LEFF'LER BARKING MACHINE HAVING FEED ROLLER POWER-DRIVEN AT 2,774,397 CERTAIN PERIPHERAL SPEED OR LOG-DRIVEN AT HIGHER SPEED Original Filed Oct. 31, 1952 2 Sheets-Sheet 2 7 8 IO 26 p i r INVENTOR. M

United States Patent POWER-DRIVEN AT CERTAIN PERIPHERAL SPEED OR LOG-DRIVEN AT HIGHER SPEED v.) Nils Gustav Leflier, Sundsbruk (near Sundsvall), Sweden,

assignor to Svenska Cellulose Aktiebolaget, Stockholm, Sweden Original application October 31, 1952, Serial No. 317,980. Divided and this application February 12, 1954, Serial No. 409,912

Claims priority, application Sweden November 3, 1951 Claims. (Cl. 144-247) This invention relates to improvements in barking machines of the kind having at least one barking member movable into and out of engagement with the log, said machines having at least one of the two elements, the barking member and the log, adapted to rotate relatively to the other. The invention consists mainly therein, that in the feeding path of the log there is rotatably provided at least one member connected to a driving mechanism and resting against the log being fed, said rotatable member being so arranged in supporting means swingable under the influence of the log, that its journal axis and the axis of the swinging shaft of the supporting means are situated on opposite sides of the axis of the log, the axis of said swinging shaft being spaced from the periphery of the log, and the rotatable member resting against the log with a pressure which not only depends on the feeding resistance but which will increase automatically with increasing feeding resistance.

An exemplary embodiment is shown in the accompanying drawings. Fig. l is a side elevation of the machine, a portion of the outer casing being broken away, and other parts being broken away and shown in section to better reveal the mechanism within it. Fig. 2 is a composite sectional view of the right hand end of the apparatus as shown in Fig. l, as indicated by the section lines 2L-2L and 2R2R. Fig. 3 is a detail elevation ofthe roller conveyor at the right hand end of the apparatus shown in Fig. 1, as indicated by the line 3-3.

Referring to the drawings, 1 is a rotary drum or the like (Fig. 1), which by means of bearings 2 is supported by a nonrotary tube 3 rigidly secured to a frame 4. In the drum 1 one or more, for example six, shafts 5 are turnably mounted. At one end of each shaft 5 there is secured a barking member 6 in the shape of a scraping element located within an annular stationary bark-collecting housing 44. Inside a bearing plate 7 there is secured to each shaft 5 a sleeve plate 8 actuated by one end of a helical spring 9, which at its other end is secured to a sleeve plate 10, which is adapted to turn on the shaft 5 and to which a centrifugal weight 11 is secured. In Figures 1 and 3 the log 12 is shown. For damping the movement of the weights 11 and, consequently, also of the barking members 6 rubber plates 13 are provided.

Upon rotation of the drum 1 the centrifugal Weights 11 are thrown outwards, each weightactuating by way of the sleeve'plate the" spring'Q an'dth'en also the barking member 6, which thus-is pressed inwards ready for engagement with the log.

For feeding the logs the following means are provided. 7

As will be seen from Figures 1 and 2, feed rollers 19 are mounted on arms 20, the latter being turnably mounted on brackets 21. 'In order that the log shall always be kept at the reenter the. arms'20 are connected to an arm 23 by means of links 22, said arm being in turn mounted in a bracket 24 secured to the frame. The driving of the rollers may be provided for by a cylindrical gear 25 and a chain drive 26. The shaft of the gear 25 may be absorber 29.

driven from a power source (not shown) which is connected to the shaft by means of a key-groove 48. The drive between the two feeding mechanisms formed by the rollers 19 may be transmitted by means of a chain or, for example, by means of a horizontal shaft, two chain wheels being required in the former case and two mitre gears being required in the latter case. Said details are not shown in the drawings. The drive of the upper rol-' ler is effected by means of a chain 27. The contact pressure is obtained from a spring 28 and the bump arising when the log is leaving the rollers is damped by a shock The conveyor may be made as a belt conveyor, as sh'ov or as a roller conveyor in avconventional manner and cooperating shoulders 47.

preferably it is driven at the same peripheral speed as" that of the feeding mechanisms. The roller 31 is, however, arranged in a'special way, bringing about considerable advantages.

As shown in the drawings the roller 31 is turnably mounted by a shaft 43 bearing in the free ends of two arms 32. Said arms 32 are attached at their lower ends (e. g. welded) to a sleeve 45 which is journalled on a shaft 33 between two brackets 34. The ends of the shaft 33 are turnably mounted by the brackets 34. The contact pressure of the roller is adjusted by means of springs 35 and the degree of compression of the springs should be so chosen that the roller will contact the log with a slight pressure. p

The roller 31 may be driven by means of a separate motor or also, as shown in the drawing, from the fore feeding mechanism. A chain wheel 36 is provided'on the gear 25 and drives the shaft 33 by way of a chain wheel 37, which may be connected to an overrunning clutch 33 The clutch illustrated has spring operated pawls 46 and On said shaft 33 there is secured a chainwheel 39, which by way of a chain 40 and a chain wheel 41 drives the roller 31. The gear ratios may be chosen in such a manner that the roller 31 is driven at a somewhat lower but certain peripheral speed than are the rollers of the feeding mechanisms, and'the overrunning member of the clutch should be arranged in V such a manner that it wiil be in engagement when, by means of the chain driving means, the roller is driven at the abovementioned certain peripheral speed, but it should admit of the roller being driven at a higher peripheral speed by the log. It is not necessary in this connection to deal more particularly with the construction of the overrunning clutch, because the abovemen tioned condition will be obtained by any conventional one-way engaging clutch which automatically transmits torque in one direction of movement but not in the opposite direction.

If the driving of the roller 31 is arranged in this way, said roller will serve as an auxiliary roller, i. e. it will not feed the log except in case the speed or" the latter should become reduced for some reason or other, so that its speed will become-lowerthan the certain peripheral speed; of the roller. Consequently, the feeding means" of machine will function in the following mannerrBy means of a device not shown in the drawing a logis placed on the conveyor 30 and by the latter is moved toward the barking members. The log will first meet the roller 31, and will then simultaneously swing it upward and toward the drum, so that the log is able to pass under the roller.

Since the roller is partly balanced by the spring 35 the Patented Dec. 18, 1956 come too large."

a s t t o with a log. The contact pressure of the roller against the 7 log will of course also be very low and feeding spikes 42 'of the roller will make no marks or markings in the Wood' that will cause the formation of splinters in the surface of the log, when the barking members are applied.

Next, the log meets the fore rollers 19 of 'the feeding mechanisms. If the log enters directly betweenthe same then no change takes place in the mode of Operation of the roller 31. Should the log, however, be stopped by the rollers 19, the roller 31 will take over the feeding and willcause thelog to enter between the rollers 19. The axial or feeding component of;tlie contact pressure of .the roller 31 on the log will' then be dependent on the 7 existing feeding resistance, and it is advantageous that the greater the'feeding resistance, the g'reatehwill become the feeding component of thecontactpressure. Itis very easy to predetermine therelation between the horizontal feeding component and thevertical component by choosinga proper initial angle of inclination for the arms'32,

It is advantageougtoo, for the contact pressure to increase i log, means connecting said member to a driving mechlog, said supporting means being swingable about a second having at least one barking tool movable into and out of engagement with an axially fed log, the barking tool and the log being relatively rotatable about a longitudinal axis. of an axially fed log; and: said machine having conventional means for feeding a log at a given axial spee d, said improvement comprising at ,least oneyrotatably driven member located in a feeding. path'of an'axially fed anism which rotates said member at a certain-peripheral speed not exceeding said given axial speed of a'log, means 7 supporting said member for rotation about an axis transverse to and spaced from said longitudinal faxis of '2. fed

transverse axis spaced froni that; side of saidilongitudina'l axis opposite to said first transverse axis and also} spaced from said log-feedingpath an oncoming :log' 'e n gaging' V said member and swinging said supporting means about 'When debarking thick logs, and this occurs because the 7 arms 32 will bemoved to a more vertical position than by thin logs and will correspondingly, increase the compres? sion of the spring 35.

As soon as the log has entered between the fore rollers 19 it will be driven by said rollersat the higher peripheral speed. The feeding component of the contact pressure of the roller. 31 on the log will then be reduced to zero orless, as before the introduction of the logbetween the rollers 19, and the roller 31 will again be rotated by the 'log. p 7 When the log then meets the barking members 6, the 7 same condition'sarise as'when itmetthe fore rollers 19. It said rollerstare able to'pres s the log in between the ibarking members the roller 31 will not carry outany feeding work but it will begin to drive the log, if the log should said second transverse axis until said member restsagainst V a log, whereby said driving mechanism willflcause'said member to drive a log forward only when the axial speed: a of a log, becauseof too much feeding resistance, drops' 1 below said certain peripheral speed. 7

2. An improvement in a barking machine of the; kind having at least one barking tool movable into and out of engagement with an axially fedlog, the barkingtool and'I the log being relatively rotatable about a longitudinal axis of an axially'fed' log, and said machine having con-i V ventional means for feeding a log ata. given axial speed,

slowdown or stop. There is no risk of the feeding pressureof the roller 31 becoming so high that parts of the machine would be pressed asunder, becausethe feeding spikes 42 ofithe roller are not made sollargethat they will penetrate the wood, incase the resistance should be- I The .roller 31 brings and the back rollers 19 apart; Such damaged'areas of 'the woodwould subsequently be increased by the scrap-.

ing action of the barking members. Furthermore, the

log will skid sometimes on the .conveyor'30 and'will not enter between the fore rollers 19. By the provision of low, namely, only such pressure as is required for the barking operation alone. Should the log be slowed down orstopped the roller 31 begins to drive the log in the manner previously mentioned. Thedamage to'the wood which may be caused by said roller can be overlooked because this will only take place along very short parts i of the length of the log. V a V V Ofcourse itis not necessarythat the 'roller 31 be driven tudinal axis" opposite to'said firsttransverse axis and also' spaced from said log-feeding path,ran oncor'ninglog en-g gaging said memberand swinging said s pporting means about said. second transverse axis untils'aidmernber rests j about considerable advantages. Q Thus the surface'of the wood may easily become damaged; a by the fore rollers'19 Whenever they have to befpressed against the log hard enough to cause a high feeding pres-. V sure, as when the log has to'press the barking members said improvement comprising'at least one rotatably'driven member located in a' feeding path of'a'n axially fed-log,

means connecting saidmember to afdriving mechanism which rotates'said'meniber at a certain peripheral speed which is less than'saidgiven axial speediofa log, meansiqi supporting said member for rotation about an axis transverse to and spaced from said longitudinal axis of a fed 'log, saidsupporting means being swingable about'a, sec

ondtransverse axis spaced from that side of saidv longiagainst a log, whereby said membe'r is driven by alogat a peripheral speed which'ishigher than said certain pie-l; riph'eral, speedjwhenever a log does not: encounter too much feeding'resis tance, and whereby. said driving mocha anismvvill cause said member-to drive a log forwardonly when the'axial speed of a l'og, because :of too muclifeeding j -resistance,vdrops, belowsaid certain peripheral speed.

3, An improvement.according to claim 2, said machine including a spring for pressing 'said member against a 7 log, the biasing force of said spring being greater for thick the roller 31 the contact pressure of the rollers 19 can be. I

by means of; an overrunning clutch;- lt'may be driven directly by a chain driveand attheisame peripheral speed that will be. dependent on the feeding resistance.

'No. 317,980 filed Oct. 31, 1952. V V Having' now described my invention, wha'f'I clainr as 7 new and desire to secure by Letters Patent is: t

1 .An improvementinaibarking machine. of the kind thgconvyorBG and of theifeed rollers 19. It a will'then gbe feeding'alhthe time with a contactpressure Q i This application is a division of .my application Serial f logs than for. thin logs.

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