US2893452A - Hydraulic debarker having automatically controlled log speed and nozzle spacing, stroke and speed - Google Patents

Description

y 7, 1959 E. c. SHAW ETAL 2,893,452

HYDRAULIC DEBARKER HAVING AUTOMATICALLY CONTROLLED 1.0a SPEED AND NOZZLE SPACING, STROKE AND SPEED 4 Shepts-Sheet 1 Filed Aug. 8, 1957 INVENTOR. Emvssr- C; SHAW OIVILLI C. FRANK C LII'FORD C. J'A'cK QN' ay -Lu' (J. AmIm-cv y 1959 E. c; SHAW ETAL 2,893,452

HYDRAULIC DEBARKER HAVING AUTOMATICALLY CONTROLLED I 1.06 SPEED AND NOZZLE SPACING, STROKE AND spasm Filed Aug. 8, 1957 v 4 Sheets-Sheet 2 1 A INVENTO R.

F 2 Enucsr C. SHAW Onwu-n C. FRANK A Curran chum-sou;

ATTORNEY July 7, 1959 E. c. SHAW ETAL 2,893,452 HYDRAULIC DEBARKER HAVING AUTOMATICALLY CONTROLLED LOG SPEED AND NOZZLE SPACING, STROKE AND SPEED Filed Aug. 8. 1957 4 SheetsShee't 3 INVENTOR. C. S H A w Eaun'r Dawn: C. Fmum.

Cunwan C. Jacnsou 234.4. a AIT'ORNIY y 1959 E. c. SHAW ETAL 2,893,452

HYDRAULIC DEBARKER HAVING AUTOMATICALLY CONTROLLED LOG SPEED AND NOZZL SPEED E SPACING, STROKE AND Filed Aug. 8, 1957 4 Sheets-Sheet 4 INVENTOR. Emvzsr C. SHAW OQVILLE C. FRANK Cur-roan J'ncasou United States Patent HYDRAULIC DEBARKER- HAVING AUTOMATI- CALLY' CONTROLLED" LOG SPEED AND NOZ- znnsmcmo, STROKEvAND SPEED ApplicationAugust .8, 1957, Serial No. 677,027

Claims; (Cl'.144208) This inventio'n relates to improvements in hydraulic log debarking apparatus for debarking logs, of various S1268;

Apparatus of this type employs movable nozzles sup plied with water under high pressure to debarlca log as it is' advanced past the apparatus. The means for moving the nozzles. with respect to .the log for effective debarking thereof rand the controlmeans to adjust the apparatus fordebarking logs of various sizes. have been complicated and expensive; Furthermore, such apparatus has. been ineflicientgbecause an undue amountof vwater has been wasted.

It is the primary object of this invention, thereforato provide a'hydraulic log debarker of "simplified design withdmproved reliability and increased efiiciency at redncedcost.

Another object is to provide a debarker with a sim-' pli-fied control means of novel design to automatically adjust theapparatus for 'debarking-logs of various sizes;

The apparatus includes a frame having-a-debarking station th'rough which logs of various diam'eters'are translatedlongitudinally=along a fixed-plane. A pair of oppositely' facingnozzles aremovably mounted on opposite sidesof the logs travelingthrough the debarking station and supplied with liquid under high preasure. The nozzles are simultaneously reciprocated in straightlinexmovement' so that the liquid jets will move transversely over the surface of the log from'diametrically' aligned opposite directions.

Control. means. including :a log-diameter-sensing' ele-- meutisprovided to automatically adjust: .(1) the spacing of .zthe nozzles; .(2): the amplitude of:--their reciprocal movement from. such fixed plane; (3): the'speed of log travelgand (4) the speed of nozzle travel depending upon the diameter of thelog.v

Other-objects and advantagesof this invention will be apparenbfromathe detailed 3 description that follows and theillustrationsinthe accompanying drawings, wherein:

Fig.1 is a partially'schematic :side elevation'of a de barkingapparatus embodying the. present invention;

Fig, ,2 is afragmentary viewin side elevation with one wallinfthe: frame removed-to show the mechanism for translating logs:- ofcvarious. diameters longitudinally througha .debarking station; a Fig, .3 is afragmentary perspective (partially .schematic) view showing .the mechanism for reciprocatingthe nozzleswand icontrolling:suchnozzle movement for debarldnglogsof various sizes; 1 Fig-.;: 4 z-is; a. fragmentary end" elevation showing the actuatingaand control-.mechanisms for the nozzles;-

FigzuSxis a viewsirnilaratotFig,4 showing the actuating 2 3 and control mechanisms adjusted for logs of maximum diameter; and

Fig. 6 isaview similar. to Fig. 5 showing .the; mecha: nism adjusted for logs of minimum. diameter.

While the invention. is shown. and described asap paratus for debarking logs, it should beunderstood that the invention may be embodied in any device wherein treatment of elongated objects with a liquid jet is contemplated.

The-machine comprises a debarking station .l0 enclosed by a housing or frame 11for the prevention of splashand a conveyor mechanism 13 for translating logs 12. and 14 (Fig 2) of various diameters longitudinally through'the deb-arking station; The .conveyor may be of any known type havingaxtrough-like table .or bed' on which a cylindrical object will be supported in astable position during the debarkingoperation. If a stationary trough or bed is used suitable known means may beu'sed to push or pullthe object alongthe bed for trough but, in the preferred form illustrated in the drawings, the conveyor mechanism 13. comprises a plurality of fliite'd or. spiked V rolls 16 mounted .for rotationon shaft's 17 journaled in the frame ll'and an endless chain 18 ..drivingly connecting spur gears 15 on the. shafts 17. The conveyor. mechanism 13.is driven (Fig. l) by a motor 19 through a variable-speed transmission 20, drive shaft 21, chain drive 22, shaft'23', and bevel gears 24 which drive the shaft'17 farthest to the. left (Fig. 2) to translate logs 12 and 14 of various diameters longitudinally from right to left (Fig. 2) along a substantiallvfixed horizontal'plane 25 (at lowermost point of peripheral surface of the logs). j

A plurality of plate steel baflles 26, 27, 28and30 are pivotally mounted at one end above the conveyor and connectedto a plurality ofdashpot cylinders 32 mounted on the outside of the frame. The free ends of the. baffles ride on the top surface of the logs to. hold them firmlvin' position while passing through the machineand also help to keep the spray and bark from spurting outof the. ends of .the frame housing. As will be .explained'morel'ully. hereinafter, the bafile 28*is. also utilized in: the. control mechanism of the machine. I

The logs are debarked by the action of hydraulic jets upon the .peripheral surfaces thereof. Thesehydraulic jets willremove bark over a substantial area surrounding the point of impact. but if. allbark is to be removed from a log passing on a conveyor it will be necessary either to provide a greatmany jetsor. to move the point *of--.irn'- pingernent of one or more jets cireurnferentially with relation .to the log surfaceas. the 'logmoves longitudinally without rotation. The .present invention contemplates the use of a smaller number of jets than would be re quired to remove all barkwithout relative circumferena tial motion, and to do so by moving the points of'impact of these jets transversely in reciprocal straight-line motion as the log passes longitudinally. through the debarking statlon.

The debarkeris equipped with two pressure nozzles 34 preferably'of stainless steel with apertures machined 'to eject a flat stream of water or other suitable liquid. The nozzles are threaded onv nozzle connectors 36 which in turn are securely mounted in crossheads 38 with the nozzles directed so that the flat sides of the jets are substantially parallel to'the longitudinal axis of the logs, and so that'the 'jets are-parallel to the substantially fixed hori zontal plane 25 along which the logs travel. The nozzles are supplied (Fig. l) with water or other liquids under and connectors 36 directly in the movable crossheads 38 eliminates many of the support problems generally encountered in movably mounting nozzles supplied with liquids under high pressure.

The nozzles 34 and connectors 36 which extend into the interior of the frame 11 through openings 33 in the sides thereof are actuated in a straight-line reciprocal movement by the crossheads 38 slidably mounted in vertical guideways 46 which in turn are slidably mounted for movement toward and away from the logs on the outside of the frame opposite one another.

The nozzles 34 mounted in the crossheads 38 are reciprocated vertically from a point in plane 25 at the bottom of the logs by a pair of counterbalanced lever arms 48 and 50 connected to the crossheads 38 by connecting 'rods 52. The counterbalanced lever arms are driven by a drive shaft 54 which is in turn driven by a drive lever :56 fixed to the drive shaft and connected to a fixed-throw crank 58 on a shaft 62 by a connecting rod 60, a link 63 and a crosshead 61 slidably mounted on the drive lever 56. The fixed-throw crank 58 is driven by the motor 19 from the shaft 23 by means of a chain drive 68 connected between sprocket wheels 66 and 64 on the shafts 23 and 62, respectively. The counterbalanced lever arm 50 is driven by the lever arm 48 through a connecting link 70 and pivots on a shaft 72 as the lever arm 48 is pivoted on the drive shaft 54 by the drive lever 56 as the fixedthrow crank 58 is rotated by the drive motor. The nozzles 34, therefore, reciprocate in alignment with each other from the plane 25 with the water jets from the respective nozzles moving transversely over the surface of a log passing through the debarking station.

To completely debark a log in this manner it is imperative that the water jets sweep across the entire surface of the log from top to bottom and vice versa. It is also important that the amount of jet overtravel be minimized to keep water loss low and thereby increase efliciency. This is accomplished by a simple, accurate and reliable control mechanism which will now be described.

The means for controlling the operation of the debarking nozzles responsive to logs of various sizes (Figs. 3, and 6) includes the baffle 28 which serves as a logdiameter-sensing element to automatically adjust the amplitude of the reciprocal movement of the nozzles from the fixed plane 25, the spacing of the nozzles on either side of the log, the speed of log travel and the speed of nozzle travel. As logs of various sizes are conveyed past the debarking station the free end of bafile 28 which rides on the top surface of the logs will move up and down depending on the diameter of the logs. Movement of the baflle 28 is transmitted to the crosshead 61 slidably mounted on the drive lever 56 by a linkage mechanism (Fig. 3) comprising a shaft 78 on which the baflie 28 is mounted, a crank 80, connecting arm 82, crank 84, shaft 86, crank 88, and link 90 connected to a control piston rod 92 of a pneumatic servo cylinder 93. An upward swing of the baflle 28 will move the control rod 92 of servo cylinder 93 downwardly causing a power piston rod 94 of the servo cylinder to move downwardly. Down ward movement of the piston 94 will rotate a shaft 96 through a crank 98 which will in turn actuate an adjusting rocker arm 100 on the shaft 72 by means of a crank 102 (on the shaft 96) and connecting link 104. The adjusting arm 100 mounted on the shaft 72 will slide the crosshead 61 up and down (towards and away from the drive shaft 54) on the drive lever 56 in response to movement of the baffle 28. In the example given, an upward swing of the baffle 28 as it rides up on a log of increased diameter will cause the crosshead 61 to slide up on the drive lever 56 to a'point closer to the axis of drive lever 56.

As clearly shown in Figs. 5 and 6, the position of crosshead 61 on the drive lever 56 will determine the amplitude of the nozzle stroke from a substantially stationary base point (plane 25). Fig. 5 shows the crosshead 61 on the drive arm 56 in a position for debarking a thick log. The solid lines of Fig. 5 show the position of the parts when the nozzles are at the lowermost point in the reciprocal movement thereof. The dotted lines (Fig. 5) show the position of lever arms 48 and 50 after the crank 58 has been rotated from the solid-line position to a point near the top of the nozzle stroke. Fig. 6 shows the crosshead 61 on the drive arm 56 in a position for debarking a thin log. The solid lines of Fig. 6 show the position of the parts when the nozzles are at the lowermost point in the reciprocal movement thereof. The dotted lines (Fig. 6) show the position of lever arms 48 and 50 after the crank 58 has been rotated from the solid-line position to a point (corresponding to that shown in Fig. 5) near the top of the nozzle stroke. It is noted that the solidline positions of the lever arms 48 and 50 in both Figs. 5 and 6 are substantially the same even though the position of crosshead 61 on the drive lever 56 is at the two extremes of adjustment. A comparison of the dotted-line positions of lever arms 48 and 50 in Figs. 5 and 6 clearly demonstrates the difference in the height or amplitiude of nozzle stroke as the crosshead 61 is slidably adjusted on the drive lever 56 in response to variations in diameter of logs passing under the baflle 28.

The substantially constant lowermost point of nozzle travel (plane 25) is maintained throughout the range of adjustment of the crosshead 61 on the drive lever 56 by the particular construction of the drive mechanism employed. As shown in Figs. 5 and 6 an are 105 described by rotating the connecting rod about its pivotal connection to the fixed-throw crank 58 in the solid-line positions shown will intersect the longitudinal axis 107 of drive lever 56 at two points which represent the positions of crosshead 61 on the drive lever 56 at either end of its range of adjustment. The amount of error (variation from plane 25) of the base point of nozzle stroke in all positions of the crosshead 61 will vary with the length of connecting arm 60. The longer the arm the less the resulting error.

Simultaneously with the adjustment of the amplitude of nozzle stroke in the manner previously described, the horizontal spacing of the nozzles on either side of a log will be correspondingly adjusted to accommodate logs of various diameters. The guideways 46 are slidably mounted on either side of the debarking station on triangular rods 106 and are movable in response to movement of the baffie 28. As previously explained, movement of the baffle 28 will rotate the shaft 96. Rotation of the shaft 96 will slide the guideways 46 (Fig 3) by means of a crank 108, connecting arm 110, crank 112, shaft 114 and double-throw crank 116 pivotally connected at one end to the guideway on the right by a link 118 and pivotally connected at the other end to the left-hand guideway by a connecting arm 120. When the baffle 28, for example,

is swung upwardly in response to a log of increased diameter the position of guideways 46 will be automatically adjusted outwardly away from the path of log travel simultaneously with the adjustment of nozzle-stroke amplitude (increase) in the manner previously described.

Since the conveying mechanism 13 and the mechanism for actuating the nozzles are driven from a common drive shaft (shaft 21) the amount of longitudinal travel of a log past the debarking station for each complete stroke of the nozzles will remain constant no matter at what speed the shaft 21 is driven by the motor 19. It is desirable that the speed of nozzle travel be maintained at a constant predetermined speed for proper debarking of the logs. It is noted in this connection that if the speed of shaft 21 remains constant the nozzle-travel speed will increase when the amplitude of nozzle stroke is increased. To compensate for this variation in nozzle speed due to the variations in nozzle stroke amplitude, a speed-control mechanism is employed which will vary the speedof drive shaft-'21 in response to changes in log diameter. This mechanism (Fig. 1) includes a crank 122 mounted on'an end of the shaft 78"which carries the baflie*28,' which actuates the variable-speed transmission 20 through a connecting arm 130, bell crank 132, connecting arm 134, bell crank 136, and connecting arm=138 pivotally connectedto a lever 140 which actuates the variable-speed transmission 20. Therefore, when the bafile 28 is swung upwardly in-response to a log of larger diameter .the control mechanism just described will actuate the variablespeed transmission to reduce the speed of drive shaft 21 and thereby maintain the nozzle-speed travel at a predetermined speed.

A brief summary of the operation of the device is as follows:

A log 12 is introduced into the machine (Fig. 2) and is translated longitudinally from right to left along the fixed plane 25 by the conveying mechanism 13. The log will contact the bafiie 30 which serves to hold the log in a stable position and will then contact the baffle 28 which will slide up on the top surface thereof and automatically adjust the amplitude of nozzle stroke so that the jets from the nozzles will move transversely of the log from the plane 25 at the bottom thereof up to the top of the log. The battle 28 will also position the nozzles with respect to the sides of the log at the proper distance therefrom. The speed of log travel and also the speed of nozzle travel will be adjusted in accordance with the position of bafiie 28 to maintain a predetermined nozzle speed. As log 12 passes the debarking station and is followed by a log 14 of smaller diameter the baflie 28 will move down from the thicker log 12 to the top surface of the thinner log 14, as shown in Fig. 2. This repositioning of baffle 28 will automaticaly reduce the amplitude of nozzle stroke to correspond to the diameter of log 14 and the spacing of the nozzles will also be adjusted inwardly closer to log 14. The speed of log travel will be increased so as to maintain the same speed of nozzle travel notwithstanding the decrease in the amplitude of nozzle stroke.

We claim:

1. A hydraulic log-debarking apparatus of the type in which logs of various diameters are translated longitudinally along a fixed plane comprising, a frame having a debarking station, a pair of spaced oppositely facing nozzles movably mounted on said frame at said station on opposite sides of logs passing therethrough, means for feeding liquid under pressure to said nozzles, actuating means for imparting reciprocable straight-line movement to said nozzles from said fixed plane so that the jets of liquid from said nozzles will move transversely over the surface of a log passing through said station, and control means for said actuating means including a log-diametersensing element to automatically adjust the amplitude of the reciprocal movement of said nozzles from said fixed plane.

2. A hydraulic log-debarking apparatus according to claim 1 in which said actuating means includes a crosshead slidably mounted in a guideway for each nozzle, said nozzles being fixedly mounted in said crossheads and said guideways being slidably mounted on said frame for movement toward and away from a log passing said debarking station.

3. A hydraulic log-debarking apparatus according to claim 1 in which said actuating means includes a drive shaft rotatably mounted on said frame, a drive lever fixedly mounted on said shaft, a fixed-throw crank operatively connected to said drive lever by a connecting rod to oscillate said drive lever and thereby pivot said drive shaft when said fixed-throw crank is rotated, said drive shaft being operatively connected to said nozzles to actuate said nozzles as said drive shaft is pivoted.

'4. A hydraulic log-debarking apparatus according to claim 3 in which said control means includes a crosshead slidably mounted on said drive-lever and pivotally connected to said connecting rod, said crosshead being operatively connectecl to said log-diameter-sensing element and-slidable .therebyto vary the effective length of said drive lever acting-on said drive shaft to thereby vary the stroke of said nozzles to accommodate logs of varying; diameter.

5. A hydraulic log-debarking apparatus according to claim 4 in which the longitudinal axis. of saididrive lever, when said nozzles are at the end of a stroke at said fixed plane intersects an: arc, that would .be formed atthat time if the pivotal connection of said crosshead to said connecting rod were rotated about the pivotal connection of said connecting rod to said fixed-throw crank, at two points which represent the positions of the sliding crosshead on said drive lever at either end of its range of adjustment.

6. A hydraulic log-debarking apparatus of the type in which logs of various diameters are translated longitudinally along a fixed plane comprising, a frame having a debarking station, a pair of spaced oppositely facing nozzles movably mounted on said frame at said station on opposite sides of logs passing therethrough, means for feeding liquid under pressure to said nozzles, actuating means for imparting reciprocable straight-line movement to said nozzles from said fixed plane so that the jets of liquid from said nozzles will move transversely over the surface of a log passing through said station, and control means for said actuating means including a log-diametersensing element to automatically adjust the spacing of said nozzles.

7. A hydraulic log-debarking apparatus of the type in which logs of various diameters are translated longitudinally along a fixed plane comprising, a frame having a debarking station, a pair of spaced oppositely facing nozzles movably mounted on said frame at said station on opposite sides of logs passing therethrough, means for feeding liquid under pressure to said nozzles, actuating means for imparting reciprocable straight-line movement to said nozzles from said fixed plane so that the jets of liquid from said nozzles will move transversely over the surface of a log passing through said station, and control means for said actuating means including a log-diametersensing element to automatically adjust the amplitude of the reciprocal movement of said nozzles from said fixed plane and the spacing of said nozzles.

8. A hydraulic log-debarking apparatus of the type in which logs of various diameters are translated longitudinally along a fixed plane comprising, a frame having a debarking station, a pair of spaced oppositely facing nozzles movably mounted on said frame at said station on opposite sides of logs passing therethrough, means for feeding liquid under pressure to said nozzles, actuating means for imparting reciprocable straight-line movement to said nozzles from said fixed plane so that the jets of liquid from said nozzles Will move transversely over the surface of a log passing through said station, and control means for said actuating means including a log-diametersensing element to automatically adjust the amplitude of the reciprocal movement of said nozzles from said fixed plane, the spacing of said nozzles, and the speed of log travel.

9. A hydraulic log-debarking apparatus of the type in which logs of various diameters are translated longitudinally along a fixed plane comprising, a frame having a debarking station, a pair of spaced oppositely facing nozzles movably mounted on said frame at said station on opposite sides of logs passing therethrough, means for feeding liquid under pressure to said nozzles, actuating means for imparting reciprocable straight-line movement to said nozzles from said fixed plane so that the jets of liquid from said nozzles will move transversely over the surface of a log passing through said station, and control means for said actuating means including a logdiameter-sensing element to automatically adjust the amplitude of the reciprocal movement of said nozzles from said fixed'plane, the spacing of said nozzles, the speed of log travel, and the speed of nozzle travel.

10. A hydraulic log-debarking apparatus having means for moving logs longitudinally along a path, a nozzle directed at a log on said means and reciprocally mounted -for movement away from and back toward a fixed plane substantially tangent to said logs while remaining parallel to said plane, means for supplying water under, high pressure to dischargethrough said nozzle, means controlled by the diameter of a log moving along said path to move said nozzle toward and away from such a log and to 8 change the amplitude of the reciprocal movement of said movement from said plane, and means, controlled by the diameter ofa log moving along said path to control the longitudinal speed of travel of such a log and the 5 speed of the reciprocal travel of said nozzle,

References Cited in the file of this patent UNITED STATES PATENTS Shaw Feb. 19, 1952 Hansel May 31, 1955 2,765,012 Riddell et al.- Oct. 2, 1956

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