US2950743A - Pole shaving apparatus having bark breaker - Google Patents

Description

Aug. 30, 1960 J. T. NAPIER ET AL POLE SHAVING APPARATUS HAVING BARK BREAKER 2 Sheets-Sheet 1 Filed Nov. 26, 1957 JOE 7T JESS F M MURRAY @4, wwww ATTORNEYS POLE SHAVING APPARATUS HAVING BARK BREAKER Joe T. Napier, Cam-arillo, and Jess F. MacMurray, Alameda, 'Calif., assignors to J. H. Baxter & Co., San Francisco, Calif., a corporation Filed Nov. 26, 1957, Ser. No. 699,030

3 Claims. (Cl. 144-208) This invention relates to apparatus for shaving wood poles, and more particularly, to an improved device for debarking and smoothing such poles.

In the processing of logs into utility poles, piling, and the like, it has been found highly desirable to remove the bark from the log. Most poles in this type of service are treated with a wood preservative and most log bark substantially impedes the absorption of the preservative or other treatment material into the log. In addition, the bark usually has a roughened and uneven surface and is undesirable both from the utility and appearance standoints.

P On logs from certain types of trees and under certain conditions, the bark may be relatively loose and can be hand peeled. The cost of hand peeling is, however, relatively high compared to mechanical peeling, and may be extremely difficult in cases where the bark is securely adhered to the log. In some instances, apparatus such as wire brushes may be used to clean up logs where a majority of the bark has been otherwise removed.

It will be noted, however, that the bark next to the wood surface on a log is usually the toughest and most ditficult to remove. It has therefore been found that apparatus of the type which shaves the bark from the log is most practical. It is also desirable to remove a thin slice from the log itself under the bark so as to open the surface of the log to permit greater penetration of the wood preservative.

Certain types of logs, principally the cedar, are known to have bark comprising extremely tough, long fibers which extend longitudinally of the log. Such tough, stringy bark is not only especially difiicult to remove, but may become fouled in the equipment in which the shaving is done. In apparatus in which rotatable shaving heads shave relatively wide swaths of bark from the log long strings of cedar bark are likely to become wrapped around said heads and their bearings and seriously interfere with the shaving operation.

In addition, such long stringy bark is diificult to convey away from the apparatus once it has been removed from the log. The bark from fir logs may be equally difficult to handle since it often breaks off in large pieces. This may also interfere with the shaving operation, causing substantial irregularities in the finished pole.

It is therefore an important object of this invention to provide a device for breaking the bark on a log into relatively short lengths prior to removing said bark.

Another object of this invention is the provision of means for shaving the bark from logs in shorter, more manageable pieces than has heretofore been accomplished.

A further object of this invention is the provision of a means for removing the bark from logs in which the bark is kerfed prior to being removed.

It is still another object of this invention to provide apparatus for shaving the peripheral bark layer from logs in such a manner that the removed bark may be readily disposed of without injury to the apparatus.

tnt E ise Other objects and advantages will become apparent from the following description taken in connection with the accompanying drawings, in which:

Fig. l is a side elevational view of the apparatus of this invention, the lower portion of the bark cutter being broken away to show a depth gage shoe;

'Fig. 2 is an enlarged sectional view taken through the shaving head generally along line 22 of Fig. 1;

Fig. 3 is an enlarged top plan view as seen generally from line 3-3 of Fig. 1;

Fig. 4 is a semischematic view showing a pole being shaved by the apparatus of this invention; and,

Fig. 5 is an end elevational view of the bark breaker as seen from line 5-5 of Fig. 2.

In detail, referring to Fig. 1, the apparatus of this invention includes a relatively rigid frame 1 upon which are mounted conveyor means, generally designated 2, and the pole shaving means, generally designated 3. The conveyor means 2 is adapted to convey a log 4 (the end of which is shown in dot-dash lines in Fig. 1) transversely of the frame 1 and at the same time to rotate said log under shaving means 3.

The conveyor means includes a pair of driving wheels 5, n which are mounted in radial alignment on a pair of spaced, parallel, horizontal shafts 7, 8 journaled in an elongated frame member 9. Said driving wheels are mounted so that their peripheries are slightly spaced from each other (Fig. 3) and the log 4 is adapted to ride in the V formed by the upper peripheries of the wheels (Fig. 1). Drive wheel 5 is formed with a rubber-like friction surface or tire 1ft whereas the periphery of wheel 6 is formed with a plurality of radially extending teeth 11 for frictionally engaging the periphery of log 4.

Both of said driving wheels are driven in the same direction by a connecting chain 12 between the shafts 7, 8, the former of which is driven by a motor 13 through a chain 14. It will be obvious that a log 4, in the position shown in Fig. l, with its periphery in contact with the peripheries of wheels 5, 6 will be rotated in the direction of arrow 15 about its longitudinal axis.

The complete assembly of wheels 5, 6, motor drive 13, and frame 9, are all mounted on central vertical pivot 16 (Fig. 1) on frame 1 so that it may swing about said pivot. This movement is shown more clearly in Fig. 3 in which it is seen that the conveyor means assembly may be canted or angularly disposed with respect to the longitudinal axis of log 4 by swinging said assembly in the direction of arrow 17. The wheels 5, 6 when so angularly disposed with respect to the log cause advancement of the same across the conveyor means in the direction of arrow 18, while at the same time said log is being rotated. It is obvious that a change in the angularity of wheels 5, 6 with respect to the path of travel of log 4 varies the rate of advancement of said log along said path. In this manner, conveyor means 2 both conveys a log along a longitudinally extending path of travel in one direction, and at the same time axially rotates said log for a purpose to be described.

Shaving means 3 comprise a pair of shaving or planer heads, generally designated 19, 20 (Fig. 3). Said shaving heads are mounted over the path of travel of the log through conveyor means 2 and each is independently mounted for movement toward and away from said log in the direction of arrow 21 (Fig. 1). The heads 19, 29 are similar and like reference numerals will be used in describing the same. Head 19, which is the first to be engaged by a log travelling in the direction of arrow 18 (Fig. 3) is the roughing head, whereas the succeeding head 20 is the shaping or smoothing head.

Each of the shaving heads comprises a housing of guard 22, which is open at the bottom and is rotatably connected to the end of an arm 23. As will later appear,

housings 22 are supported for rotational movement about the longitudinal axes of elongated arms 23 so as to conform to the shape [of the log being shaved. Each of arms 23 is rigidly secured to a bracket member 24 (Fig. l) which is swingably mounted on frame 1 about a pivot 25 extending parallel to the'longitudinal axis of log 4 for swinging arms 23 through vertical arcs in the direction of arrow 21. Such swinging may be powered by a hydraulic cylinder 50. Brackets 24 each also carry a motor 26 which is connected by means of V belts 27 to a pulley 28 (Fig. 3) on the shaving head shaft 29 (Fig. 2) of each head 19, 20. v 7

Each shaft is journaled in bearings 30 supported in bearing plates 31 mounted on opposite ends of each housing 22. Said bearings are capped by retainers 32 which overlie gaskets 33 of the plates 31. Shafts 29 are each also provided with inner and :outer seals 34, 35, respectively, to assist in preventing bearing lubricant leakage.

Each shaft 29 is provided with an enlarged, coaxial, cylindrical body portion 36 between inner seals 34. A plurality of slots 37 are formed opening outwardly of the periphery of portion 36 and extending generally axially thereof for receiving elongated cutting knives 38 project- 7 ing therefrom. The slots 37 are tapered, as in a convenshoes 41. Plates 40 are formed with relatively large apertures 42 through which the ends of shaft 29 pnoject and said plates are supported in side brackets 43, 44 (Fig. '1) secured to housing 22, for movement of plates 40 vertically with respect to said shaft.

A sliding wedge element 45 is connected by a tongueand-groove joint 46 (Fig. 2) to each guide plate 40..

Joint 46 extends along the upper edge of plate 40 and is slantingly disposed (Fig. 1) with respect to a line normal tothe guiding edges of side brackets 43, 44 so that movement of element 45 along the said upper edge of plate 40 causes vertical displacement of latter and its associated shoe 41 with respect to shaft 29. Such movement of element 45 is caused by a hydraulic cylinder 47 (Figs. 1, 3) which incorporates a movable piston having a rod 48 connected to element 45.

Each of the shoes 41 on each side of shaving heads 19, 20 is thereby independently controllable.

arms 23 are swung downwardly thereagainst by cylinders 50. The depth of the cut taken by rotating knives 38 is regularities in, and the natural taper of, the periphery of the log. A latch 51, operated by a hydraulic cylinder 52, is provided for each head 19, 20, to prevent the head from tilting as the end of the log 4 is moved from under the head.

By this structure each of the shaving heads may be moved into engagement with the periphery of the log 4 on conveyor 2 for shaving a relatively wide swatch of the bark 53 (Fig. 4) from said log. It will be noted that preferably'noughing head 19 is set for just cutting through the bark 53 and only slightly shaving the wood The shoes 41 engage the periphery of a log 4 on conveyor means 2 as of the log under the bark. Smoothing cutter is preferably set to take only a slight shaving or thin slice of wood from the periphery of the pole to finish the surface thereof.

The rate of rotation of the log 4 and the rate of forward movement of the log under heads 19, 20 is related to the width of the swaths of bark cut (which is equal to the length of the cutting pattern of knives 38) in a manner that assures complete stripping of the bark. Preferably the heads 19, 20 shave in a helical path around the log such that the pitch of said helical path is justslightly less than the length of the cutting pattern of the heads (Fig. 4). In other words, the circumferential swaths of bark cut from the log are related to the rate of advance of the log past the shaving heads so that one complete swath is cut per revolution of the log. This may of course be adjusted by swinging the conveyor frame 9 about pivot 16.

Any suitable means may be employed to support the ends of the log 4 as it is being'advanced by conveyor 2. Carts with rotatable log-supporting means may carry the ends of the logs to and from conveyor 2.

As previously mentioned, pole-shaving'apparatus of this type is often met with difficulties where the bark 40 is tough and stringy as in cedar logs. Since roughing head 19 cuts a relatively wide swath, because of the elongated cutting pattern of knives 38, long strings of cedar bark tend to come loose and wrap around the shaft 29 and the shaving-head body 36 and interfere with the rotation thereof. In order to overcome this serious disadvantage, this invention provides a method of circumferentially kerfing the bark prior to removing the bark by cutting relatively wide swaths therefrom. In effect, the bark 53 of the log 4 is cut into short, longitudinal lengths approximately equal to the width of the swath later cut to remove the bark from the log.

One preferable form of apparatus for performing this method in conjunction with the apparatus heretofore described is a toothed cutter, generally designated 55 (Figs. 2, 4, 5) mounted on the outboard end of an extension of the shaft 29 of roughing head 19. Cutter 55 comprises a relatively thin, generally circular holder 56, which has a central aperture for receiving the end of shaft 29, which is extended opposite the direction of movement of log 4. Holder 56 may be secured on the end of shaft 29 by any conventional means 'such as nut 67 (Fig. 2). Said holder is provided with a plurality of slots 57 opening outwardly of the periphery of the holder for receiving relatively axially narrow teeth 58 therein. Conventional wedge 59 and screw 60 means may be provided for holding teeth 58 in slots 57 with the cutting edges of the said teeth projecting outwardly from holder 56. In this manner the cutting edges of teeth 58 describe a relatively narrow cuttingpattern at a location spaced axially from the. relatively wide cutting pattern of roughing head 19.

Although the particular form of cutter 55 described is preferable it will be understood that a circular saw or other cutting means may be used in its place. The diameter of the cutting circle described by teeth 55 is just slightly smaller than the diameterof the cutting circle of teeth 38 (see the dot-dash circle 38 in Fig. 5) of roughing head 19. This relationship will, of course, remain constant, since both are mounted coaxially on the same shaft 29. Likewise, the depth of cut of both cutting head 55 and roughing head 19 will be set by the positioning of shoes 41 as previously described.

As the log 4 is passed under the roughing head 19 by conveyor means 2, cutter 55' first forms a relatively narrow kerf through the bark 53 of said log'. Since the bark next to the wood of log 4 is generally the toughest, cutter 55 is preferably set to a depth so as to just cut through said bark. This narrow kerf, which is formed in a helical path by the movement of log 4 by conveyor means 2, breaks the bark into relatively short lengths approximately equal to the width of the swath cut by roughing head 19. Since roughing head 19 is set to the same cutting depth as cutter 55 but has a slightly larger diameter, said roughing head will peel a relatively wide swath of bark 53 from the log after kerfing by cutter 55. Roughing head 19 also peels a thin shaving of wood from the log itself under the bark thereby removing the mark formed by cutting head 55. Subsequently, smoothing head 20 shaves a thin layer of the wood from log '4 to smooth the surface thereof and to open the pores for subsequent chemical treatment and the like.

In eifect, the bark 53 on a log 4, is first cut, by circumferential kerfing, into a plurality of short lengths of bark which may be easily removed by the shaving head 19. This prevents the shaving head from peeling long stringy fibers of bark that might otherwise become fouled with the rotating shaving head, and other mechanism of this device. In addition, the relatively short lengths of bark that are shaved from the log in this manner are more easily conveyed away from the shaving s1te.

It is obvious that means other than those specifically described and illustrated may be employed to cut the bark into short lengths prior to shaving the bark from the log, and it should be understood that modifications that would occur to those skilled in the art are intended to come within the meaning and scope of the appended claims.

We claim:

1. Apparatus for shaving bark from logs comprising: conveyor means for conveying a log along a longitudinally extending path of travel in one direction and at the same time axially rotating such log, a shaving head mounted for rotation about an axis parallel to said path and including axially elongated, radially projecting peripheral cutting edges, means for rotating said shaving head, means mounting said shaving head for movement transversely of said path for engaging said cutting edges with the periphery of a log in said path for shaving a relatively wide swath of bark from such log, and a barkbreaking head mounted coaxially with said shaving head for rotation therewith and axially spaced therefrom on that side opposite said one direction, said bark-breaking head having a plurality of radially projecting, relatively axially narrow, peripheral cutting teeth engageable with the periphery of such log in said path ahead of said shaving head for cutting a relatively narrow kerf through such bark of a log being shaved.

2. Apparatus for shaving bark from logs comprising: conveyor means for conveying a log along a longitudinally extending path of travel in one direction and at: the same time axially rotating such log, a shaving head mounted for rotation about an axis parallel to said path and including axially elongated, radially projecting, peripheral cutting edges, means for rotating said shaving head, means mounting said shaving head for movement transversely of said path for engaging said cutting edges with the periphery of a log in said path for shaving a relatively wide swath of bark from such log, and a barkbreaking head mounted'coaxially with said shaving head for rotation therewith and axially spaced therefrom on that side opposite said one direction, said bark-breaking head having a plurality of radially projecting, relatively axially narrow, peripheral cutting teeth engageable with the periphery of such log in said path ahead of said shaving head for cutting a relatively narrow kerf through such bark of a log being shaved, the radius of said cutting edges being only slightly greater than the radius of I said cutting teeth.

3. Apparatus for removing peripheral bark layer from an elongated, generally cylindrical log where such bark is composed of long, tough, longitudinally extending fibers, said apparatus comprising: a shaving head having a plurality of elongated cutting edges describing an elongated cutting pattern of predetermined length, means for relatively rotating a log with respect to said shaving head at a predetermined rate of rotation, means for moving said shaving head into engagement with such log with said cutting pattern extending longitudinally of such log for removing its bark, means for relatively moving said shaving head longitudinally with respect to such log at a rate related to said rate of rotation and said length of said cutting pattern such that a circumferential swath of bark substantially equal in width to said length is removed by said shaving head during each complete relative rotation of such log and said shaving head, and a cutting head provided with a plurality of relatively narrow cutting teeth and mounted in association with said shaving head for movement therewith into engagement with such bark for circumferentially kerfing such bark at a plurality of spaced points prior to removal by said shaving head.

References Cited in the file of this patent UNITED STATES PATENTS 2,188,502 Emmons Jan. 30, 1940 2,305,281 Taylor et a1. Dec. 15,1942 2,328,545 Bukowsky Sept. 7, 1943 2,581,617 Alfsen Jan. 8, 1952 2,688,349 Nicholson Sept. 7, 1954 I 2,781,802 Pence Feb. 19, 1957 2,795,320 Dillingham June 11, 1957 FOREIGN PATENTS 141,296 Sweden July 21, 3

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