US3643710A

US3643710A - Method and machine for making bamboo veneer and products thereof

Info

Publication number: US3643710A
Application number: US874283A
Authority: US
Inventors: Chester Manfield Fitzgibbon
Original assignee: BELIZE PLYWOOD AND VENEER CO I
Current assignee: BELIZE PLYWOOD AND VENEER CO I
Priority date: 1969-11-05
Filing date: 1969-11-05
Publication date: 1972-02-22
Anticipated expiration: 1989-02-22

Abstract

A method of making bamboo veneer including subjecting a debarked green bamboo trunk to softening by moisture and heat, cutting the trunk to a desired length, decoring the trunk by forcing a plunger longitudinally therethrough, straightening the decored and softened trunk by applying pressure internally and externally to the trunk, and simultaneously cutting a thin veneer from the trunk while rotating the trunk. The invention further contemplates a machine for performing the described method and bamboo products utilizing the formed veneer as, for example, bamboo plywood.

Description

United States Patent Fitzgibbon 51 Feb. 22, 1972 [54] METHOD AND MACHINE FOR MAKING BAMBOO VENEER AND PRODUCTS THEREOF [72] Inventor: Chester Mantield Fitzgibbon, Seattle,

Wash.

[73] Assignee: Belize Plywood and Veneer Company, Inc.,

Union City, NJ.

[22] Filed: Nov. 5, 1969 [21] Appl.N0.: 874,283

[52] US. Cl. ..144/3 R, 144/209 R, 144/46 [51] Int. Cl ..B27l 5/02 [58] Field ofSearch ..144/3, 209, 14,48, 35,46,

[56] References Cited UNITED STATES PATENTS 689,035 12/1901 Brainard ..144/3 X 701,081 5/1902 Pierce ..144/14 FOREIGN PATENTS OR APPLICATIONS 1,003,617 9/ 1965 Great Britain 144/ 209 Primary ExaminerDonald R. Schran Attorney-Berman, Davidson & Berman [5 7 ABSTRACT A method of making bamboo veneer including subjecting a debarked green bamboo trunk to softening by moisture and heat, cutting the trunk to a desired length, decoring the trunk by forcing a plunger longitudinally therethrough, straightening the decored and softened trunk by applying pressure internally and externally to the trunk, and simultaneously cutting a thin veneer from the trunk while rotating the trunk. The invention further contemplates a machine for performing the described method and bamboo products utilizing the formed veneer as, for example, bamboo plywood.

7 Claims, 14 Drawing Figures PATENIEBFEBZZ me I 3,648,710

METHOD AND MACHINE FOR MAKING BAMBOO VENEER AND PRODUCTS THEREOF BACKGROUND OF THE INVENTION The present invention relates generally to a method of making bamboo veneer, a machine for making bamboo veneer, and the products of the method and machine including the veneer and plywood formed from said veneer.

Heretofore, bamboo plywood has not been manufactured, or marketed, in commercial quantity because of the expense and difficulties involved in making bamboo veneer. Such difficulties arise out of the fact that bamboo shoots and trunks are inherently extremely resilient and hard to cut. Also, they are normally of relatively small diameter as compared to other trees, the largest being about ten inches in diameter, so that it is extremely difficult to shave, r peel thin veneers from their surfaces and obtain any substantial amount of veneer from a single shoot. Added to this problem are those arising from the prevalency of curved, bent, or crooked trunks, and the periodic variation in external diameter of a trunk at the joints along its length by reason of the circular knots, or protuberances surrounding the trunk marking of such trunks and the previous location of branches.

SUMMARY OF THE INVENTION The invention contemplates a method and machine for making bamboo veneer, the key steps of which include subjecting a debarked green bamboo trunk to softening by moisture and heat, forcing a plunger through the trunk to decore the same, straightening the decored and softened trunk by applying pressure internally and externally, and simultaneously cutting a thin veneer from the trunk by applying a cutting blade to the outer surface while rotating the trunk in its pressurized condition.

The invention further contemplates a machine which follows the preceding steps in its mode of operation and the bamboo plywood products obtainable upon use of the bamboo veneer.

It is a primary object of the invention to provide an improved method and machine, for making bamboo veneer, which will enable the ultimate manufacture of bamboo plywood and bamboo plywood products.

It is an important object of the invention to provide a method and a machine for making bamboo veneer which will readily form a veneer having substantially uniform thickness and pleasing appearance showing the characteristic grain of the bamboo tree.

Another object of the invention is to provide an improved method for making bamboo veneer which is easy to perform, and an improved machine for making bamboo veneer which is easy to use and which entails relatively little expense in such use and in initial cost.

Still another object of the invention is to provide bamboo plywood in commercial quantities along with the advantages of such plywood, including extremely good resistance to shrinkage, checking, or expansion, and high resistance to absorption ofwater.

A still further object of the invention is to provide bamboo veneer plywood which is termiteproof and will not rot, and which is otherwise long lived and resistant to deterioration for any reason.

BRIEF DESCRIPTION OF THE DRAWINGS The novel features that are considered characteristic of the invention are set forth with particularity in the appended claims. The invention, itself, however, both as to its organization and its method of operation, together with additional objects and advantages thereof, will best be understood from the following description of specific embodiments when read in connection with the accompanying drawings, wherein like reference characters indicate like parts throughout the several Figures, and in which:

FIG. 1 is a plan view of a machine, according to the invention;

FIG. 2 is a sectional view taken along line 22 of FIG. 1, and looking in the direction of the arrows;

FIG. 3 is an enlarged sectional view taken along line 3-3 of FIG. 1, and looking in the direction of the arrows;

FIG. 4 is a fragmentary, enlarged sectional view taken along line 44 of FIG. 3, looking in the direction of the arrows;

FIG. 5 is a sectional view similar to FIG. 4, but taken along line 5-5 of FIG. 3, and looking in the direction of the arrows; FIG. 6 is a fragmentary, sectional view, similar to FIG. 5, but showing the pressure roller lowered to rotate a bamboo trunk and the cutting blade engaged during peeling of the veneer;

FIG. 7 is an elevational view taken along line 77 of FIG. 3, and looking in the direction of the arrows;

FIG. 8 is an enlarged, sectional view taken along the line 8-8 of FIG. I, and looking in the direction of the arrows;

FIG. 9 is a fragmentary plan view showing the decoring cutter ready to enter the bore of the bamboo trunk for decoring the same;

FIG. 10 is a side elevation of the decoring cutter shown in FIG. 9;

FIG. 11 is a front elevation showing the decoring cutter of FIG. 10 as viewed from the right-hand side;

FIG. 12 is an enlarged, sectional view taken along line 12- 12 of FIG. 1, and looking in the direction of the arrows;

FIG. 13 is an exploded view showing the plies of veneer ready to be stacked and compacted into plywood; and

FIG. 14 is a sectional view of the plywood product obtained upon stacking and compressing the plies of FIG. 13.

DESCRIPTION OF THE PREFERRED METHOD OF MAKING BAMBOO VENEER In performing the method of making bamboo veneer, according to the present invention, green, but mature, bamboo trees are first selected and cut from the forest and the green skin, or bark, along with the branches, are removed from the trunks in any suitable manner. During this step the joints, or periodic exterior protuberances are preferably also substantially removed by grinding, sanding, or cutting.

To soften the trunks thus debarked, they are cooked in a vacuum cooker, or steam is applied under pressure for a period of time lasting from one to two hours. The pressure is not critical, but the higher the pressure the sooner the trunks will be adequately softened.

The softened trunks are then cut to a uniform length, selected in accordance with the width of the veneer it is desired to form from the trunks.

The next step involves inserting a plunger through each trunk to clean out the interior core which comprises an internal sheath of pith and a series of thin rings, or partitions extending partly or entirely across the bore aligned with the external joints and branches, which have been substantially removed previously along with the bark.

Next, the trunk is straightened by applying internal and external pressure, or pressure members, to the bore and to the external surface, preferably, by squeezing the trunk between an internal hanger member and an external pressure roller. Simultaneously, the trunk is caused to rotate by rotating the internal and external members, and a blade is applied to the exterior surface to peel off a veneer of desired thickness. While such straightening, rotating and simultaneous peeling; or cutting, are easily performed with the above-stated internal and external pressure members, other ways of applying pressure and other forms of pressure members may be utilized. For example, the trunk may be held at its ends between rotating chucks and air under pressure may be admitted to and out of the bore of the trunk through the chucks to apply straightening pressure against one or more outer fixed, or rotating members aligned either parallel with the trunk, or placed at intervals therealong so that the trunk will be straightened while it is subjected to the cutting action of the blade. In this way the problem of trunk bends, curvature and taper are overcome and to some degree, any remaining joint protuberances.

tntrnx Once the veneer strip has been continuously cut from the external surface of the trunk, the cutting continuing until virtually the entire trunk has been sliced, or peeled, leaving only thin fragments of material at the inner surface, if any, the peeled, or stripped veneer is dried in a conventional veneer drier in the same way as any other wood veneer is dried.

The novel and key steps in the method described above comprise the steps of softening the bamboo trunks, decoring the trunks by passing a plunger through their bores, and rotating the trunks while squeezing the same between internal and external straightening members so that a uniform thickness of veneer will be cut by the cutting blade. During the cutting the blade angle with respect to the surface of the trunk is adjusted so that a uniform thickness is obtained despite the fact that the diameter of the trunk is being more or less rapidly reduced by the cutting operation.

DESCRIPTION OF A MACHINE FOR MAKING BAMBOO VENEER A preferred embodiment of a machine for making bamboo veneer is illustrated in FIGS. 112 of the drawings, the machine being generally indicated by the reference numeral 10, and having a cutting station generally designated 12, a decoring station generally designated 14, and a peeling station generally designated 16. The bamboo trunks are moved from station to station by a conveyor in the form ofa pair of identical endless chain link belts 18, the upper courses of which ride in slots in table 22. At spaced intervals along each belt the chain links are provided with upstanding pin abutments 24 which serve to move a bamboo trunk 26 carried by the belts along the surface of the table top 22 from station to station. Each chain belt is trained over a drive sprocket 28 situated at the right end and under the table, as viewed in FIGS. 1 and 2, and a similar, undriven sprocket 30 under the left end of the table, the corresponding sprockets at each end being fixed to axles 32,34 respectively, so as to revolve together and uniformly.

A power source 36, which may be an electric motor, is shown supported on a lower platform 38 fixed to the supporting legs 40 of the table 22. The motor 36 has a pulley 42 on its drive shaft and over which is trained an endless belt 44 which is also trained over pulley 46 affixed to a horizontal shaft 48 journaled in bearings 49, FIG. 12, under table 22 beneath the upper courses or the conveyor chains 18. Shaft 48 carries a pair of circular saw blades 50 keyed thereto, the saw blades protruding through slots 52 in the table, and at a distance apart corresponding to substantially the desired width of bamboo veneer to be fabricated. Through belt 44 the saws 50 are driven continuously to cut the bamboo trunks into logs of uniform length at the cutting station 12.

Pulley 42 is connected by belt 54 to input pulley 56 ofa gear reduction device 58 to drive the latter and input shaft 60 of compressor 62. The output shaft 64 drives a conventional timer 66, employing cams, or the like. The timer has an output shaft 68 which intermittently drives another gear reduction device 70 having an output sprocket 72 connected to shaft 32 by the endless chain 74 and another sprocket 28, similar to the drive sprockets 28 for the conveyor chain belts 18. Thus, the conveyor is driven intermittently with a dwell time, which may be set on the timer to correspond with the delay necessary at the decoring and peeling stations to permit operations at these stations to be performed before the chain belts are restarted to move the bamboo logs to and from the machine stations. The compressor 62 develops a supply ofpressurized air for operating pressure fluid devices on the machine at various stations, as will later appear.

Referring particularly to FIGS. 1, 2 and 3, it will be seen that a horizontal platform 76 is supported above the table 22 and extending completely across and beyond the table, being supported on

columns

78,80. This platform is positioned at the peeling station 16 and carries two rearwardly extending.

spaced brackets 82 to which is pivotally connected the bight 84 ofa U-shaped clamping member 86. The clamping member has rearwardly extending arms 88 bent in inverted V-shape, which engage the tops of bamboo trunks at the decoring station 14. To pivot the clamping member 86 from a raised, nonengaging, or bamboo release position to an engaging, or bamboo-holding position, as illustrated in FIG. 2, the bight 84 of the clamp has affixed thereto an upstanding crank arm 90 to which is pivoted the piston rod 92 of a fluid pressure cylinder device 94 whose cylinder is pivoted at 96 to the platform 76. The fluid pressure cylinder 94 is provided with inlet and outlet couplings, not visible in the drawings, to which are connected flexible tubes, not shown, which, in turn, are connected to the compressor 62, or to a pressure reservoir, not shown. lnflow of pressure fluid to move the piston and piston rod, and thereby the clamping member 86 between the hold-' ing and release positions, and vice versa, are controlled by conventional valves which may be manually, or automatically operated in a conventional manner. in the holding position of the clamping member 86, the arms 88 engage the bamboo trunk 26, as illustrated in FIG. 2, pressing the same against the table top 22 and rearwardly against a pair of lugs 24 on the chain belts 18, which, as previously described, have been stopped at the decoring station. The bamboo trunk is, therefore, fixedly positioned crosswise of the table and prevented from endwise movement by an upstanding plate 98 secured to the table 22.

Referring more particularly to FIGS. 1 and 8 through 11, it will be seen that the decoring station 14 includes a platform 100 slightly below the table 22 and secured thereto by brackets, or the like, not shown. The platform 100 has fixedly supported thereon a fluid pressure motor 102 having inlet and outlet couplings 104,106 and a rotor 108. Between the motor and the table 22 is supported a fluid pressure cylinder having a piston 112 and piston rod 114 extending from the piston and out of the cylinder in opposite directions. One end 116 of the piston rod is keyed to the motor rotor 108 by a spline and the opposite end of the piston rod carries a pivot pin 118 which connects the apices of a pair of cutters 120,122 each being formed as a segment of a cone with the pivot pin 118 at the apex. Each cutter has a cutting edge 124 formed at one side. The bases of the cone segments are integrally formed, or connected to rearwardly extending, cylindrical segments, or shoes 126. The shoes are outwardly biased by coiled springs 128,130 seated between sockets on the piston rod 114 and sockets in the internal surfaces of the shoes 126. The base of each cutter blade is pivoted at 132 to a link 134, the other end of which is pivotally connected to a bolt 136 which rides in a slot 138 in the piston rod. As a result, the pair of cutters 120,122 are pressed apart by the coiled springs 128,130 to a maximum distance depending upon the length of the slot 138, the length of the links 134 and the diameter of the bore of the bamboo trunk being cut. The shoes 126 ride in the bore against the inner surface of the hardwood lining the bore to prevent further spreading of the cutters. The construction of the cutters, as described, is such that the cutters are adapted to enter the hollow bores 140 of the bamboo trunks, of varying internal and external diameters, and adjust to the internal diameters so as to completely decore the trunks, the blades piercing and cutting away the layer of pith 142 and the webs, or partitions 144 present at each joint of the bamboo trunks. it will be apparent that operation of suitable valves in the fluid pressure system to actuate the motor 102 and the cylinder device 110 will cause the cutters 120,122 to rotate and simultaneously move to the right in FIG. 8, entering the bore 140 of a bamboo trunk clamped on the table at the decoring station 14, and cutting out the pith and the webs 142,144 forming the core through the complete length of the bamboo trunk to make the same completely hollow.

The piston rod 114 of the decorer is hollow and connected at its end opposite the cutters by flexible tubing 146 to the compressor 62, or a pressure reservoir, so that while the fluid pressure cylinder 110 is operated to force the cutters through thin-m n'v-na bamboo trunk at the decoring station, air under pressure is fed through the piston rod 114 into the bamboo trunk to blow out the core chips cut by the cutter blades and the pithy waste in the bamboo, such material being forced out through an opening 148 in the stop plate 98 so that the bamboo trunk, when it leaves the decoring station, is completely hollow and clean.

The mechanism at the peeling station 16 is illustrated in FIGS. 1 and 3 through 7, and includes a fluid pressure cylinder 150 secured by the pin 152 and bracket 154 to the platform 76, the pressure cylinder having an inlet 156 and an outlet 158 for coupling pressure hoses. The piston rod 160 extends from the cylinder device over the platform and is connected to a bifurcated pusher element 162, best seen in FIG. 3, by means of a gooseneck appendage 164, The gooseneck rides in a slot 166 in the platform support 80, and the pusher element is adapted to engage one end of the bamboo trunk when it reaches and stops at the peeling station so that the subsequent operation of the cylinder 150 will draw the pusher element 162 to the left, as shown in FIG. 3, and thereby move the hollow bamboo trunk onto an axially aligned hanger rod 168 positioned at one side of the conveyor table 22. The hanger rod is journaled at both ends in journals 170,172 supported on fixed pedestals 174,176 on the platform 177 fixed below the table 22. A pressure fluid motor 178 is mounted on the platform support 78 by bolts, or the like, and has inlet and outlet couplings 180,182. The pressure fluid motor is coupled at 184 to one end of the hanger rod 168. The other end of the hanger rod is journaled in semicircular bearings 186, FIG. 7, each fixed in a pivoted member 188, the pivot being shown at 190 and forming part of the journal 172. The members 188 are respectively fixed to a pair of arms 192 whose outer ends are pivoted at 194,196 to a pair of links 198 whose other ends are pivotally coupled at 200 to the piston rod of the pressure fluid device 202. The journal members 188 are shown in their open condition in FIG. 7, permitting the pusher 162 to push a bamboo trunk over the hanger rod. Actuation of the pressure cylinder 202 to move the piston downwardly in FIG. 7 will close the journal members 188 about the end of the hanger rod after the bamboo trunk has been pushed thereon, the parts being shown in their closed condition in broken lines in FIG. 7.

Fixed to the underside of the platform 76 are a pair of aligned journals 204,206 which support a pressure roller 208 above and parallel to the hanger rod 168. The pressure roller is provided with a plurality of longitudinal ribs terminating in outer sharp, or knife, edges for biting into a bamboo trunk, impaled on the hanger rod, and rotating the same. Each of the journals is supported by a cylinder pressure device 210 having an inlet coupling 212 for admitting air, or other pressure fluid, and a piston 214, FIG. 6, therein whose rod 216 is fixed to a downwardly protruding bearing support member 218 for rotatably supporting the pressure roller. The bearing support 218 is pressed downwardly, as shown in FIG. 6, by a coil spring 220 seated between the cylinder device 210 and the bearing support, so that the pressure roller 208 is normally in its downwardly biased, bamboo-engaging condition, but may be lifted to disengage the bamboo and to admit entrance of another bamboo trunk between the pressure roller and the hanger rod by operation of the cylinder devices 210 in their upward directions. Desirably, the springs 220 are surrounded by protective housings 222.

To drive the bamboo trunk through the pressure roller 208, the shaft 224 of the pressure roller is extended through a slot 226 in bearing 170, and a gear 228 is fixed thereto. Gear pinion 228 meshes with a similar gear 230 fixed to the hanger rod 168 so that as the motor 178 turns the hanger rod and gear 230 the drive is transmitted through the gear 228 to the pressure roller which squeezes against the bamboo on the hanger rod and turns the same.

An elongated knife 232 is positioned at one side of the hanger rod and mounted on a member 234 pivoted to the edge of a table 236 so that the knife blade edge may engage the exterior surface of the bamboo to peel a thin veneer layer 238 therefrom. The peeled layer, as it is being cut from the rotating bamboo trunk, feeds onto the receiving table 236, FIGS. 1 and 6. The member 234 has a gear segment 238 attached thereto which meshes with a worm 240 on the shaft 242 which may be turned by an operator to adjust the thickness of the cut and to vary the angle ofthe peeling blade as cutting progresses on a particular bamboo trunk. This arrangement is such that the operator of the machine can adjust the blade to peel a substantially constant depth veneer strip from the rotating bamboo until the blade reaches a minimal distance of, say, one thirty-second inch from the hanger rod so that all remains of the bamboo trunk being peeled is a very thin tube adjacent the original inner surface which tube can be cut by the knife so that it will fall away from the hanger rod at the end ofthe peeling process. Once a particular bamboo trunk has been peeled, the cylinders 210 are actuated to lift the pressure roller and the journal members 188 are opened so that the next log carried by the chain conveyors on table 22 to the peeling station is ready for insertion between the pressure roller and the hanger rod by operation ofthe pusher cylinder 150.

It will be apparent from the above description that the machine operates in the following manner. Bamboo logs of varying lengths are fed from a hopper, not shown, to the left end of the table 22 in FIG. 1, where they are picked up individually by a pair of pins 24 on the chain belts 18 and intermittently carried toward the cutting station 12. On reaching the cutting station, the saw blades 50 cut off the ends of each bamboo trunk so that it leaves the station as a trimmed log of selected length equal to the width, or slightly longer, of the veneer desired. As a given log reaches the decoring station 14, the chain conveyors l8 stop for a delay period during which the clamping member 86 is rotated downwardly to engage its top and hold the log fixed, whereupon the cylinder is actuated to push the cutter blades 120,122 through the bore of the trunk while rotating the same by means of the motor 102 to decore and blow out the chips and the waste core material. Simultaneously, a bamboo log which is stopped at the peeling station 16 is pushed onto the hanger rod 168 by the pusher element 162 activated by fluid cylinder 150. The motor 178 is actuated to rotate the hanger rod and the pressure roller 208 after the latter is lowered into engagement with the log so as to turn the log. The operator adjusts the peeling knife 232 against the outer surface of the log to begin peeling the veneer 238, and continues said adjustment until the log is completely peeled. The pressure rod cylinders 210 are then actuated to lift the pressure roller, and these cylinders are tied in which the journal cylinder 202 to open, or spread, the journal mem bers 188, at which time the delay period is ended and the chain belts 18 again move bamboo logs along the table 22 toward the cutting, decoring and peeling stations, the bamboo log which leaves the decoring station moving to the peeling .station 16, whereupon the next delay occurs and the decoring and peeling operations are repeated. It will be apparent that the various pressure fluid devices at the decoring and peeling stations may be operated manually by the operator in proper sequence during the delay period of the chain conveyors 18, or their control valves may be arranged in a timing system to operate in the appropriate sequence so that the operator need be concerned only with the proper adjustment of the peeling knife during the peeling operation.

DESCRIPTION OF A PREFERRED BAMBOO PRODUCT Veneer made by the process and machine described above may be used for making a bamboo plywood particularly for marine use in building boats, and the like, where it is waterproof quality is most desirable. Other than marine applica tions, where the highly advantageous characteristics enumerated above are important, will be obvious. In addition, of course, the veneer may be used for purely decorative purposes in applying a single ply to wood furniture, decorative wall panels, and similar articles. In making plywood, any desired thickness of veneer may be used varying, for example, from one-sixteenth inch to say seven thirty-second inch, and any number of plies such as three, five, seven, or more may be utilized in the plywood. A three-ply plywood would consist of a bamboo veneer with the grain running in the same direction on the face and back plies, while the intermediate ply is positioned so that its grain crosses at an angle, preferably 90, to the grain of the outside plies. A five-ply plywood product would include a center veneer core with the grain running in the same direction as the face and back plies and separated from the latter by two intermediate veneer plies in which the grain runs at an angle, preferably at right angle, to that of the face and back plies. By thus arranging odd numbers of plies with adjacent plies having the grain running in different directions, desirably at right angle to each other, a strong product is obtained as in conventional plywoods using other types of wood.

The bamboo veneer plies are arranged as described above, the plies being coated, on their faces, and if desired, along their edges, in accordance with conventional plywood practice, by a suitable glue selected from the phenolic, melamine, resorcinol and urea resins, or caseine glue, or vegetable glue. The plies are then subjected to compacting pressure and heat in accordance with conventional practice in the plywood industry to form the plywood bamboo product.

In FIG. 13 is shown an exploded view of three veneer sheets which have been produced by the method, or the machine described above. The veneer face and back plies 238,238 are arranged with the grain running in the same direction as shown, while the core, or intermediate ply 238" is arranged with the grain running perpendicular to that of the face and back plies. These plies are coated with a suitable glue, as previously explained, and then compacted under heat and pressure to form a plywood panel 244 of any selected size, as shown in H6. 14. The panels of plywood will generally fall in the range of sizes from A inch by 4 foot by 8 foot to 1 inch by foot by 9 foot.

The bamboo plywood product is usable for making interior decorative panels for walls in buildings and houses, exterior siding, for building boats, and the like. As previously explained, the bamboo veneer will not shrink, check or expand, and it is extremely waterproof because it will not absorb water and subsequently expand and shrink, drying out the water and breaking the bond of the waterproof glue utilized in making the plywood product. Because of the rapid growth of bamboo, a ready supply will always be available to replace bamboo utilized in a veneer and plywood industry. It takes only a year to replace bamboo which has been cut and used for any purpose.

Although certain specific embodiments of the invention have been shown and described, it is obvious that many modifications thereof are possible. The invention, therefore, is not intended to be restricted to the exact showing of the drawings and description thereof, but is considered to include reasonable and obvious equivalents.

I claim:

1. A machine for making bamboo veneer comprising a decoring and a peeling station, conveyor means for moving a bamboo trunk to said station, clamping means at the decoring station for holding a bamboo trunk in a fixed position therein, decoring means including a rotating cutter operable to move longitudinally through the bore of the trunk and remove the core thereof, means on said decoring means for projecting air under pressure ahead of said rotating cutter, means at the peeling station for straightening, smoothing and rotating a bamboo trunk, and a cutting blade at the peeling station mounted so as to engage a rotating bamboo trunk and peel a thin veneer therefrom.

2. A machine for making bamboo veneer according to claim 1, wherein said cutter of the decoring means includes a pair of conical segments each having a knife edge, said segments being pivoted together at their apexes and being biased apart by resilient means at their bases, an elongated rod fastened to the pivot of said conical segments, and means for rotatin said rod while it is moved longitudinally through the bore ofa amboo trunk clamped on the conveyor at the decoring station.

3. A machine according to claim 2, wherein said rotating means comprises a pressure fluid motor, and said means for moving the rod and its conical cutter segments comprises a pressure fluid cylinder device.

4. A machine according to claim 2, wherein said conical segments are each integrally connected to a trailing semicylindrical shoe.

5. A machine according to claim 4, wherein the base of each of said conical segments is pivoted to one end ofa link whose other end is pivoted to a slide member riding in a longitudinal slot in said rod, whereby to limit the separation of said conical segments.

6. A machine for making bamboo veneer comprising a decoring and a peeling station, conveyor means for moving a bamboo trunk to said stations, clamping means at the decoring station for holding a bamboo trunk in a fixed position therein, decoring means operable to move longitudinally through the bore of the trunk and remove the core thereof, means at the peeling station for straightening, smoothing and rotating a bamboo trunk, a cutting blade at the peeling station mounted so as to engage a rotating bamboo trunk and peel a thin veneer therefrom, said means at the peeling station for straightening, smoothing and rotating the bamboo trunk including a rod mounted at one side of the conveyor,journals near the ends of said rod supporting the same for rotation, means for rotating the rod, means for pushing a bamboo trunk from the conveyor toward the said rod, means for opening one of said journals to permit endwise receipt of the rod within the decored bore ofa bamboo trunk, means for closing said one journal once the bamboo trunk surrounds the rod, a pressure roller mounted parallel to and spaced from said rod, means biasing said pressure roller into engagement with the exterior surface ofa bamboo trunk on the rod, and means for rotating said pressure roller to thereby rotate the bamboo trunk squeezed between the roller and said rod.

7. A machine for making bamboo veneer according to Claim 6, wherein said biasing means for the pressure roller comprises coil springs, said pressure roller being movable away from said rod against the pressure of said springs by pressure fluid means to admit a bamboo trunk over the rod and to release a bamboo trunk after peeling.

Claims

2. A machine for making bamboo veneer according to claim 1, wherein said cutter of the decoring means includes a pair of conical segments each having a knife edge, said segments being pivoted together at their apexes and being biased apart by resilient means at their bases, an elongated rod fastened to the pivot of said conical segments, and means for rotating said rod while it is moved longitudinally through the bore of a bamboo trunk clamped on the conveyor at the decoring station.

5. A machine according to claim 4, wherein the base of each of said conical segments is pivoted to one end of a link whose other end is pivoted to a slide member riding in a longitudinal slot in said rod, whereby to limit the separation of said conical segments.

6. A machine for making bamboo veneer comprising a decoring and a peeling station, conveyor means for moving a bamboo trunk to said stations, clamping means at the decoring station for holding a bamboo trunk in a fixed position therein, decoring means operable to move longitudinally through the bore of the trunk and remove the core thereof, means at the peeling station for straightening, smoothing and rotating a bamboo trunk, a cutting blade at the peeling station mounted so as to engage a rotating bamboo trunk and peel a thin veneer therefrom, said means at the peeling station for straightening, smoothing and rotating the bamboo trunk including a rod mounted at one side of the conveyor, journals near the ends of said rod supporting the same for rotation, means for rotating the rod, means for pushing a bamboo trunk from the conveyor toward the said rod, means for opening one of said journals to permit endwise receipt of the rod within the decored bore of a bamboo trunk, means for closing said one journal once the bamboo trunk surrounds the rod, a pressure roller mounted parallel to and spaced from said rod, means biasing said pressure roller into engagement with the exterior surface of a bamboo trunk on the rod, and means for rotating said pressuRe roller to thereby rotate the bamboo trunk squeezed between the roller and said rod.