US2340532A - Veneer lathe - Google Patents

Description

Feb. l, 1944. J. o. JAcKsoN VENEER LATHE 8 Sheets-Sheet 1 Filed June 25, 1941 Feb. 1, 1944,

J. O. JACKSON VENEER LATHE Filed June 25, 1941 8 Sheets-Sheet 2 Feb.l, 1944.

`J. O. JACKSON VENEER LATHE Filed June 25 1941 8 Sheets-Sheet 3 Feb. l, 1944.

J. O. JACKSON VENEER LATI-IE Filed June 25, 1941 8 Sheets-Sheetl 4 Feb. `l, 1944. J. 0.,.1AcKsoN VENEER LATHE Filed June 25 1941 8 vSheets-Sheet 5 J. O. JACKSON VENEER LATHE Feb. l, 1944.

8 Sheets-Sheet 6 Filed June 25, 1941 Feb. 1, 1944.

J. o. .JAcKsoN 2,340,532

VENEER LATHE Filed June 25, 1941 asheets-sheet '7 Feb. 1, 1944. J. o. JAcKsoN 2,340,532

VENEER LATI-IE Filed June 25 1941 8 Sheets-Sheet 8 Patented Feb. 1, 1944.

UNITED STATES PATENT OFFICE VENEEK LA'THE Jesse Jackson, Birmingham, Ala. Application June 25, 1941', Serial No; 399,721- 18 Claims.. (CL 1445209) vThis invention relates to an improvement in veneer lathes.

The object is to provide a lathe for cutting veneers with mechanism for operating the various movable parts by hydraulic-means, thus dispensing with the use of the time-honored feed-screws, chain sprockets, change gears for changing thickness of veneers, and/ orv gear-boxes and the like. By the use oi this improved mechanism', itis possible to accurately speedup the veneer cutting operation and to provide automatic control of the various moving parts by the use of. hydraulic cylinders, hydraulic pumps, a` system of piping, and valves within the reach andl control of an operator. This mechanism makes itY possible tol greatl increase the speed of positioning, a log to beheld between the hydraulically operated chucks, which may be driven by suitable electric or other` means at any desired speed. The' chucks being Ahydraulically operated make it possible to operate one or both chucks either by one control' valve or by separate valves; which valves may` bev 1ocated at any convenient place within easy reach of anl operator. A constant hydraulic pressure may be maintained on the' chucks, and that pres;- sure` may be changed to suit log conditions.` For example, large logs require more pressure than small logs just as hard logs require more. pressurey than soft logs.. Constant hydraulicpres.- sure on the end of the chucks prevents logs` from getting loose between chucks andl prevents what is commonly called wring' o uts. Also better quality veneer is produced by hydraulic chucking because no log wabblingresults to causevarying thickness ofy the veneer being. cut. In using. con ventional chucks a certain amount of losening of the chuck will result wheny actual cutting be'- gins and during the cutting*` operation; lllhis loosening is Keliminated with hydraulic pressure constantly on the chucks.

By the use of this improved mechanism itE isV possible to accurately control the. advance; of; the' cutting knife and to adjustv that` advance so that?v it,A will cut any predetermined thickness of veneerV with great accuracy.

Because of the possibility of fast adjustment@ and positively controlled kniieadvance to insuref veneer thickness accuracy, it is possible to cutz veneer much more rapidly than it has beenlcutt. in the past.

By the use of this mechanism anew andnovelf4 typelof direct drive. is afforded.r by means oflflui'd,l electric or other rnctorwhichrotates the log atiY either constant or variablespeed; and elim.inat'esI many parts, thus.- requiring less spaceand! being more eiiicient. l 'c n r With-the foregoingl and other objectsimview; the `invention consists` broadly' in hydraulic chucksfor holding they log', hydraulic means for moving the chucks; cutting-'knife and pressure plate hydraulically controlled, a back-roll at'- tached, land hydraulic means for moving. the hack-rollAz in and outof contact with the periphery of the logfwhen it is' desired tocut the'veneers into stripsas they come o'ii the log.

ln the accompanying drawings? Fig. 1 is a-planvi'ew` c Fig. 2 is alsou aY plan Viewv on" an. enlarged scale confined tothe central portion ofthe lathe;

Figi 3 is a View; in front elevation ;f

Fig. 4 also shows" the' rightehand end" of.l the lathe in front elevation on an enlarged scale'. and part ofV the right-hand end broken out;`

Fig. l5 is a viewin end' elevation; Fig. 6A is a view in end elevation of. a portion of the lathe shown onI an enlarged scale;

Fig. lV is"V avertical transverse" section on the line-1LT of Fig. 1, l'o'king'n thedir'ectio'l fftlfl arrows;y

Fig. 3 is" a hydraulic Circuit" diagram ihcl'ud valves; motor,` hydraulic pump; flow' control valves, etc. for constant speed drive and Fig. 9` is an' entire' hydraulic circuit diag-'ram similar to the' View: shown in Fig. 8, but' adapted fora variable speed" drive.. y

The'log' l is held between. two chucks 2,.wlii'ch` hold the logv at opposite ends` as is"cu's't'omary,` andi either or both ofwhichare" adapted to be drii'env at a desired revolution per miiiute As' illustrated in; the drawings,` both of'` these chucks) arerotated, preferably'byelectric motors" 3; although not necessarily sincje fluid'- or." otherv means might be employed; Spa'cell is provided?. for the accommodation of ai lbg.a`nd`l of suiiicient widthy to` afford ample Y clearance space att-he end's'o'f the logJ l'.;

lplhe'rno'tors 3 aresupported oncarriage's 5. and.

thesecarriagesareimoved'in andi out" by hydraulic. cylinders E mounted' on supports 11. the. carriages being constructed on theirlwer sidest'o slide in` and.` out between the'. Ways; 8;. whibh latter. arey capable of `lateraladjustment".totakex up for Wear-r These" ways 8 are located on* the central portion ofthe main. fiiaineor. base I'U' of` thew m achin e.

The veneer cutting; knife tl; shown in. dotted;

videdfor adjustingv it' to the" correct point,..and

a ccrrespondinglyicurved' gud' l5; whiehconstruction is providedf to" change. the .tangentialf position of the cuttingkrifel L-shapedarm IBis bolted fast to the segment I4 and the adjustment of the knife-table I2 is made through an extensible connecting rod assembly. This assembly is preferably made up of the part I'I`; the screw |8 which has right and left threads, a centrally located nut I9 thereon by means of which the screw is turned, to lengthen or shorten the connecting rod assembly and thereby adjust the .y angle 0f the Cutting knife II and the position of the slotted connecting rod proper 2|). A link 2| is pivotally mountedon the frame or base byv means of a bolt 22 at one end, and it is provided with a slot 23 extending longitudinally thereof; and a slide block 24 held bythe bolt or rivet 25 to the connecting rod proper is tted to slide in the slot 23. The connecting rod proper 20 is provided with a slot 26,`and a studZ'I, secured to and extending outwardly from the knife carriage, guides the endwise movement of the connecting rod proper 20. The assembly as a whole, is piv'ctally connected at its upper Vend to the arm I6 and at its lower end pivotally and slidably connected to the link 2|.

Besides the screw I8 for lengthening and shortening the connecting rod assembly, an adjustment of the slotted link 2| is provided through the set-screws 28.` A bolt 30 extending through the arcuate slot 3| in the lin 2| locks the link in adjusted position. The two above-described adjustments are provided rst for adjusting the pitch of the knife II, and the second, for the automatic change of that adjusted pitch as the log is cut. To get any desired angle of the knife, it,V is merely necessary to adjust the length of thefconnecting rod assembly' by either lengthening or shortening it through the adjustment of the right and left setting screw I8 and its associated locknuts. f

To prepare the' machine for automatic change of pitch of the knife as the log is cut, it is merelyV necessary to adjust the slant of the link 2| a proper amount to effect a desired degree of change of pitch as the log is cut. This is done by adjusting the set-screws 28, and'then tighten- Ving the locking bolt 30. A'

If veneer is'to be cut without automatically changing the pitch of the cutting blade II, the link 2| will be secured in a horizontal position so that the adjusted pitch of the blade will remain the same as the knife carriage advances.V

If a changing angle or automatic pitch is desired, the link 2| will'be setat the desired angle which will vcause the knife table 'I2 to tiltand change the pitch of the blade II as the knife carriage and table Vare moved in.

Forexample, whenra 24 log is chucked into Vplace the link 2| may have its adjusting screw end raised from horizontal.

Then, as the machine is started and the knife II is fed into the log,r the slide block 24 in the slot 23 will pull down on the'knife table I2 through the arm I6 and the connecting rod assembly, and will automatically cause the angle of the knife to be decreased as the log diminishes in diameter; f

1 The pressure plate 32 (shown in Figs. Sandi?) is located above and between the sides of the knife-table I2, and is held on the support32a. The entire unit is mounted on the carriage 133 slidable in the ways 34 on the main frame Ill, which carriage with the' connected parts ismoved in and out by the piston rod 39 in the hydraulic cylinder 35. At the ends ofthe knife-table I2, guides 12a are provided to slidably port 32a for the pressure plate 32.v

hoid the siip-r Y Since the pressure plate 32 must be held in close contact with the surface of the log and in close proximity to the veneer cutting knife, hydraulic means is provided for automatically maintaining this contact of the pressure plate as well as the Vquick withdrawal of the pressure plate when desired.

Rods 36 extend from lugs 36a on the back of Vthe pressure plate to a pair of equalizing bars 31, 'T101 and the hydraulic pistons 38 are connected with 1 these equalizing bars by pins 39', and these hydraulic pistons are the means for withdrawing thefpressure-plate 32 from its position against the log I. Another pair of hydraulic pistons 40 are employed to maintain the contact of the pressure-plate against the log. This Ypressure may be adjusted to suit requirements.

Hydraulic knife feeld By means of a hydraulic cylinder or cylinders 35 and a iiow control valve 'I2 hereinafter referred to, the rate of speed is controlled by which the knife I I is fed into the log, cutting a predetermined thickness of veneer, and it is a very important feature of this invention that this means can be adjusted to provide a variation in the thickness as thin as three or four-thousandths (3/1000 or 4/1ooo") of an inch. Y

The distance between the cutting edge of the knife II and the pressure plate 32 always equals the thickness of the veneer being cut, and the space between the table I2 and the pressure plate support 32a, indicated by the letter S, forms the outlet for the veneer as it is cut. The ow control valve 12, later to be described, functions as a veneer thickness selector, the'thickness of the veneer being determined by the rate of flow, that is to say, the rate of advance feed of the knife is controlled by the rate of iiow.

The hydraulic pressure plate permits the 0perator to move the plate in or retract it to permit cleaning of the knife and the plate which are held in position against the log by the aid of the hydraulic cylinder or cylinders, the operator being able to give any desired pressure byV means of a pressure regulating valve, to be hereinafter described. The quality of the veneer is determined very largely by the amount of pressure applied to the pressure plate and the pressure it exerts against the log, all of which is determined by the different types of woods, more pressure being employed for certain types of woods and less pressure for others, and/or the diameter of the logs.

It will be seen that with the above-described mechanism that it will be possible to apply any desired amount 0f pressure to the pressure plate when the lathe is in operation. 'I'he pressure plate assembly is carried directly by the carriage 33, which also carries the knife, but since the pressure plate has independent means for applying a desired amount of pressure against the log, it will be seen that therpressure plate maybe moved independently of the knife,V although its advance will also be simultaneous with the knife advance.

The numeral 50 indicates a back-roll, which is rotatably supported on a carriage 54, which carriage moves in Ways 55 on the frame or baser5| so thatV the roller can be applied to the log at any time when the log shall have been partially or entirely trued up to a'cylindrical form. The back-roll is shown in Figs. 1, 2,' 5, 6 and 7 in operative position. The frame 5I is conveniently fastenedx'to the mainframe I0 when the backroll 50 fis used, by bolts 52 `which afford ,an easy yand simple means for ,attaching and detachin-g -tne-.back-rdiframe f5.1

Hydraulic `control constant speed drive -Thecylinder-B that moves the right-hand power unit or motor 3 in .and @out and holds pressure on the end of the chuck ,iscontrolled rby the 4-way valve 60. The amount of Ppressure to .be applied 4can be regulated `to suit conditions by adjusting the pressure regulatingvalve V6| shownfin the :piping ldiagram 'disclosed in Fig. '8.. This same pressure regulating valve 6| also `controls the lpressure on the left-.hand cylinder V6 through the il-way valve 62. The Vfunction of4 this left-.hand cylinder is the same as the right-hand except thatit controls the left-hand -chuck unit.

The cylinder. 56 .controls the vmovement in and out of the back-roll through the operation of a 4-way valve 64. .In this circuit a'pressure regulating valve 65 is used, making .it possible to give the `'desired amount of pressure of :the back-roll against the log, `which v.may be adjusted vfordifferent ,types :of wood, .hard .or soft, and for cutting different thicknesses of veneer. Less pressureis applied when the back-roll :knife cuts only and likewise more .pressure is applied when the .back-.roll cuts 1/21 :thick veneer. As :the circumferenceof the log `is usually not round, a provision is made for the back-roll to follow the contour `of the log, which means that this backroll cylinder must be .arranged so that the oil can 'be relieved from the back end of the piston. This is done in either one of two ways which are shown in Fig. 28 of Ithe drauungs: A relief valve 66 may be used to let the oil go backto themain oil supplytank, or aspiring-loaded or air-charged compensator 61 may be used. This acts-as an air chamberon a pump does. The oil is forced back into this cylinder 61 moving -a -piston against a spring V(not shown), or :if air-charged, -simply compressesthe airin the chamber 61.

The advantages of va hydraulic back-roll are that the pressures may be adjusted as explainedV above, and, too, thatthe back-roll can be applied to the log at any time 'desired, ywhen cutting is rst started or after the log is partially trued up, orafter the log is completely trued up to .an approximate cylinder before the back-roll is applied. f

Heretofore in commercial practice practically,

all back-rolls have been on feed-screws which were .made right and left-hand. The veneer knife table worked on one side of the lfeed-screw and :the back-roll table `Worked on the other.

They both moved toward 4the `center of the' log backward movement. This valve j69 suppliesoilv directly; from ,tne'mainlhydraulic supply through l a pressure regulating valve y10 Ato the cylinder .35. .A four-way valve 11,1 is also used in this circuit .and is designed particularly to V.by-pass .oil around .the flow control valve 12 so that the knife-table and pressure .plate may be brought in, and retracted from the :log quickly when desired. The ilowcontrol valve 1.2 determines the speed of advance of the knife, and consequently the thickvness of veneer cut. This flow control valve 12 is 4effective 4only when oil passes :through it in one direction, while the flow in the other direction is unrestricted.

In operation the valve 69 is turned to allow oil to flow into the piston endof thecylinder `35 (through the pressure regulating valve 10) but .this oil can enter the cylinder only as fast as oil on the other side of the piston is allowed to be discharged :through the 4flow control valve 12, the fi-way valve 1| being not then used to by-pass this oil. After the-cut is completed, the valve 69 is reversed and the knife table is brought out fast, the valve 12 being ineffective in the reverse direction. The rate of flow through the valve 12 is readily changed to permit cutting any thickness of veneer within the range of the valve, usually from 1/100 to thick. The use of this control l'l2 does away .with feed-screws to move the knife table, all change sprockets for various thickness of veneer or gear boxes that may be used for this purpose, clutches, etc.

The cylinder 40, or cylindersSB-d provide the control of the pressure plate. In this particular lathe two small cylinders 38 for raising the plate andltwo small cylinders 4i] for lowering and :holdingpressure on the plate are used. This circuit includes a l-way valve 14 for controlling the direction in which pressure is applied, and a pressure regulating valve 15 is vincluded to give any predetermined pressure desired on the plate. Different pressures are required for different thicknesses of veneer and the pressure plate is an important part of a veneer lathe. The quality of veneer is determined by applying even, and the correct, pressure on the pressure-plate which is well done hydraulically.

In Fig. 8, an electric driven hydraulic pumping unit of conventional design is shown, and which pump is piped to an oil tank which is the main hydraulic oil supply to all of the above.

equipment. This pump, of course, may be driven by some other motive power than electricity if desired.

Variable speed drive The variable speed lathe is the same as theA oneabove except .that the main drive is variable speedinstead of constant speed. A variable speed drive is used in order to keep a more constant peripheral speed of the log and consequently a more constant footage per minute of veneer being cut. As the diameter of the log decreases, the main drive speed increases and this calls for a different method of feeding the knife to the log. The functions of cylinders v6, 6, and 56 are `all the same as above; as are cylinders 33-46, except on this variable speed piping diagram (Fig. 9) there are two cylinders 38 to raise 'the pressurebar and two Cylinders 49 to lower it.

Inthis circuit the oil under pressure comes from the main hydraulicV pumping unit and is distributedto all of the cylinders except the knife table cylinder 35, for which oil is metered through a variable volume pump P which is`v Vsynchronized with the rotation of the drive' power. This -variable volume pump is drivenby the main motive power, either electric motor or fluid motor, or other means, so that the volume of oil-which regulates the movement ofthe knife table cylinders is in direct relation to the speed of the main drive power. As the speed of rotation of the log increases or decreases, the speed of movement of the knife table increases or decreases, giving a uniform thickness of veneer.

A conventional form of variable volume pump is used, and it has a wheel or a slide control which varies the stroke of the pump which in turn determines the volume of oil that passes therethrough. The thickness of veneer is determined by the setting of this pump. Otherwise, the circuit on the knife-table is the same as on the constant speed drive piping diagram (Fig'lS).

The machine described in the specification is the same whether variable speed drive or constant speed drive is applied. With the constant speed drive a flow control valve 'l2 must be used, whereas with a Variable speed drive a variable volume pump may be utilized to insure proper knife advance to compensate for the change in peripheral speed of the log as it diminishes in size.

By the use of a variable speed drive, a constant peripheral speed of the log and a constant,

or nearly so, footage per minute of veneer is assured by using a variable volume pump which varies the rate of feed of the knife to the log as the main drive or revolution of the logincreases or decreases.

I claim:

1. In a veneer lathe, the combination of chucking means for holding a log, motors for rotating the chucking means, carriages for the motors, hydraulic means for moving the carriages, a pressure-plate, and hydraulic means for applying pressure to the pressure-plate and for quickly re.- moving the pressure and withdrawingY the plate, constituted by a frame, rods secured to the plate, equalizing bars connecting the rods, and hydraulic cylinders connected to the bars and frame.

2. A veneer lathe including a main frame, means for chucking a log, a knife table, a knife carried thereby, a carriage slidable on said main frame and pivotally supporting said knife table, an arm connected to said knife table, a link pivotally connected to the main frame, an extensible connecting rod pivoted to said arm and slidably connected to the link, and means for adjusting the slant of the'said link whereby the pitch of the knife is automatically changed with its progressive movement into the log.

3. In a veneer lathe, the combination of chuckingV means for a log, a Yknife-table and knife held therein, means for swinging the knife-table in the arc of a circle with the cutting edge of the knife as the center-of the arc, said means including an extensible assembly pivotally connected with the knife-table, means for varying the length of the assembly whereby to regulate the tangential position ofv the knife, and alink adjust-ably connected to the frame of the lathe and to which link the assembly is pivotally and slid-V ably connected.

4. In a veneer lathe, the combination of chucking means for a log, a knife-table and knife held there in, meansI for swinging the knife-table in the arc of a circle with the cutting edge of the knife as the centerV of the arc, said means including an assembly pivotallyconnected with the knife-table, means'for varying the length of the assembly, a link adjustably connected to the` 'frame of the lathe and to which link the assembly is connected, means for adjusting the link and with it the position of the knife-table, and means Vfor locking the link in the adjusted position.

5. In a veneer lathe, the combination of chucking means for a log, a knife table and knife held therein, means for swinging the knife-table in theA arc of a circle with the cutting edge of the knife asthe center of the arc, said means including'an adjustable support attached to some part of the frame of the lathe, means for adjusting said support, an assembly pivotally connected with the table and to the support, and means for varying the length of the assembly, and uid pressure mechanism for controlling the movement of the knife-table. l a

6. In a veneer lathe, the combination of chucking means for a log, a knife-table and knife held therein, means for swinging the knife-table in the arc of a circle with the cutting edge ofthe knife as the center of the arc, said means including an adjustable support on somev partof the frame of the lathe, means for adjusting said support, an assembly pivotally connected with the table and to the support, and means for varying the length of the assembly, a slidably mounted carriage on which the knife-table is carried, and fluid pressure means for moving the carriage and knife-table.

7. In a veneer lathe, the combination of chucking means for a log, a knife-table and knife held therein, means for swinging the knife-table in the arc of a circle with the cutting edge of the knife as the center of the arc, said means including an adjustable support located on some part of the frame of the lathe, means for adjusting said support, an assembly pivotally connected with the table and to the support, means for varying the length of the assembly and fluid pressure mechanism for controlling the movement of the knife-table, a pressure plate located above and between the sides of the knife-table, a slidably mounted carriage on which the knife-table and pressurel plate are carried, and fluid pressure means for moving the carriage with the knifetable and pressure plate.

8. In a veneer lathe, the combination of chucking means for a log, a knife-table and knife held theerin, means for swinging the knife-table in the arc of acircle with the cutting edge of the knife as the center of the arc, fluid pressure mechanism for controlling the movement of the knife tablea pressure platerlocated above and between the sides of the knife-table, a slidably mounted carriage on which the knife-table and pressure plate are carried, uid pressure means for moving the carriage with the knife-table and pressure plate, and fluid pressure means for actuating the pressureV plate independently'of the knife table. 1 9. In a veneer lathe, the combination of chucking means for alog, a knife-table and knife held therein, means for swinging the knife-table iin the arc of a circle with the cutting edge of the knife as the center of the arc, said means including an adjustable support supported on some part of theframe of the lathe, means for adjusting said support, an assembly pivotally connected with the carriage with the knife-table and pressure plate, and fluid pressure means for actuating the pressure plate independently of the knife-table.

lil. In a veneer lathe, the combination of chucking means for a log, a knife-table and knife held in the latter, means for swinging the knifetable in the arc of a circle with the cutting edge of the knife as the center of the arc, said means including an extensible wsembly pivotally connected with the knife-table, a link pivotally supported at one endon some part of the lathe, a slide block slidably connected with the link and to which block one end of the assembly is pivoted, means for moving the link on its pivot, and means for locking the link in the adjusted position whereby the pitch of the knife is automatically changed with its progressive movement into the log.

l1. In a veneer lathe, the combination of chucking means for holding a log, motors for rotating the chucking means, a pressure-plate, hydraulic means for applying pressure to the pressure-plate and for quickly removing the pressure and withdrawing the plate, constituted by a frame, rods secured to the plate, equalizing bars connecting the rods, and hydraulic cylinders connected to the bars and frame.

l2. A veneer lathe including a main frame, means for chucking a log, a knife-table, a knife carried thereby, an arm connected to said knifetable, a link pivotally connected to the main frame, an extensible connecting rod pivoted to said arm and slidably connected with the link, and means for adjusting the slant of the said link whereby the pitch of the knife is automatically changed with its progressive movement into the log. i

13. In a veneer lathe, the combination of driving mechanism for turning a log, a knife-table, a knife carried thereby, a pressure plate assembly, a carriage which carries the knife-table and pressure plate assembly, fluid pressure means for moving the carriage, fluid pressure means for moving and applying pressure to the pressure plate independently of the movement of the knife-table, a rod controlling the movement of the knife-table, a fluid circuit, a four-way valve in this circuit which controls the movements of the knife-table by supplying fluid directly from a main fluid pressure supply through a pressure valve to the cylinder, a flow-control valve and a second four-way valve in this circuit adapted to by-pass uid around the flow control valve so that the knife-table and pressure plate may be brought in contact with and withdrawn from the log quickly when desired.

14. In a veneer lathe, the combination of chucking means for a log, movably supported motors for rotating said chucking means, uid pressure means for forcing the motors toward the log, whereby to apply pressure to the chucking means, a knife-table carrying a knife, a pressure plate independent of the knife-table and cooperating therewith and constructed and arranged to move with, or'independently of, the knife-table, a variable speed drive for the motors, and a variable volume pump synchronized with the drive which varies the rate of feed of the knife to the log as the main drive or revolution of the log increases or decreases in order to maintain a constant peripheral speed of the leg resulting in a constant or nearly constant footage per minute of veneer.

15. In a veneer lathe, the combination of chucking means for a log, motors having shafts .projecting therefrom approximately in alignment with the axis of the log and adapted to extend directly to the chucking means, means for applying pressure to the ohucking means, a knifetable carrying a knife, a pressure plate, said pressure plate independent of the knife and cooperating therewith and constructed and arranged to move with or independently of the knife, a variable speed drive for the motors, and a variable volume pump synchronized with the drive which varies the rate of feed of the knife to the log as the main drive or revolution of the log increases or decreases in order to maintain a constant peripheral speed of the log resulting in a constant or nearly constant footage per minute of Veneer.

16. In a veneer lathe, the combination of chucking means for a log, motors providing a direct drive for the log, carriages for said motors, fluid pressure means for moving the carriages, a knife-table carrying a knife, a carriage on which the knife table is mounted, a fluid pressure cylinder for moving the table, a pressure plate, fluid pressure cylinders for moving said pressure plate, a piping circuit, the several cylinders in said piping circuit, controlling valves in said circuit, a

variable volume pump synchronized with the drive andl connected with the piping circuit, which pump varies the rate of feed of the knife to the log as the main drive or revolution of the log increases o r decreases in order to maintain a constant peripheral speed of the log resulting in a constant or nearly constant footage per minute of veneer.

17. In a veneer lathe, the combination of chucking means for a log including slidably mounted motors, each having a. shaft extending to the chucking means, a movably supported back roll having cutting blades thereon, fluid pressure cylinders for the motors and back roll,

a piping circuit in communication with these cylof which are attached to the chucks and provide a direct feed thereto, a movably supported knifetable and pressure bar, the knife-table carrying a knife, means for adjusting the knife-table together with the angle of the knife, independent fluid pressure cylinders for shifting the position ofthe motors which rotate the log, for feeding the knife-table forward and backward and for moving the pressure plate in and out, a piping circuit connected with the several independent cylinders, valves therein for supplying and regulating the flowfof fluid therethrough, and fordetermining the direction of movement of the several parts of the mechanism which these cylinders control, a main fluid pressure pumping unit forsupplying the fluid pressure to all the cylinders except that actuating the knife-table, and a variable volume pump synchronized with the drive of the log for supplying the fluid pressure to the cylinder actuating the knife-table.

JESSE O. JACKSON.

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