US3680613A

US3680613A - Variable thickness control for veneer lathe

Info

Publication number: US3680613A
Application number: US52491A
Authority: US
Inventors: Curtice F Daniels; Curtice F Daniels Jr
Original assignee: Individual
Current assignee: Individual
Priority date: 1970-07-06
Filing date: 1970-07-06
Publication date: 1972-08-01
Anticipated expiration: 1989-08-01

Abstract

The control includes a series of solenoid valve-controlled air cylinders which actuate shift bars to shift preselected gears of a multiple ratio gear box to transmit motive power to a knife carriage and thereby feed a veneer knife into a log at preselected variable speeds to peel veneer from the log at a desired thickness. A roller bar spaced from the knife can be shifted at a fast speed relative to the knife to adjust quickly the horizontal spacing between the knife and the bar when changing the feed rate of the knife. The roller bar can also be shifted slowly relative to the knife to vary the pressure applied by the roller bar to the veneer as it is peeled. Solenoid valvecontrolled hydraulic cylinders shift the carriage mounting the roller bar vertically between upper and lower adjustable stops to change quickly the vertical spacing between the roller bar and knife when the knife speed is changed. A common manually operated remote control makes all three adjustments of the thickness settings simultaneously.

Description

United States Patent Daniels et al.

[ Aug. 1, 1972 [54] VARIABLE THICKNESS CONTROL FOR VENEER LATHE [72] Inventors; Curtice F. Daniels, PO. Box 302,

Glendale, Oreg. 97442; Curtice F.

Daniels, Jr., 1311 NW. Hawthorne, Grants Pass, Oreg. '97526 [22] Filed: July 6, 1970 [21] Appl. No.: 52,491

Primary Examiner-Donald R. Schran Attorney-Buckhorn, Blore, Klarquist & Sparkman [57] ABSTRACT The control includes a series of solenoid valve-controlled air cylinders which actuate shift bars to shift preselected gears of a multiple ratio gear box to transmit motive power to a knife carriage and thereby feed a veneer knife into a log at preselected variable speeds to peel veneer from the log at a desired thickness. A roller bar spaced from the knife can be shifted at a fast speed relative to the knife to adjust quickly the horizontal spacing between the knife and the bar when changing the feed rate of the knife. The roller bar can also be shifted slowly relative to the knife to vary the pressure applied by the roller bar to the veneer as it is peeled. Solenoid valve-controlled hydraulic cylinders shift the carriage mounting the roller bar vertically between upper and lower adjustable stops to change quickly the vertical spacing between the roller bar and knife when the knife speed is changed. A common manually operated remote control makes all three adjustments of the thickness settings simultaneously.

17 Claims, 11 Drawing Figures PATENTEDAus 1 m2 SHEET 1 0F 6 m/WF MI L- T L W M 7 8 M 3 4 O 3 0 %4 2 44 1 4 I B 2 m m 'Iulllll fi ll l-LL LllIL INVENTORS.

BUCKHORN, BLORE, KLARQUIST 8. SPARKMAN ATTORNEYS PATENTEDMIS 1 Ian sum 2 0r 6 FIG. ll

CURTICE F DANIELS- CURTICE F DANIELS, JR

INVENTORS.

BUCKHORN, BLORE, KLARQUIST & SPARKMAN ATTQRNFYS VARIABLE THICKNESS CONTROL FOR VENEER LATHE BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control for a veneer lathe whereby the lathe can be adjusted quickly to change the thickness of veneer peeled from a log.

2. Description of the Prior Art In the past a great amount of time was required to change the thickness settings of a veneer lathe. Because of this, it has been common practice to peel a given log at a constant thickness. The thickness of peel was determined by visual inspection from the outside appearance of the log. If the log appeared to have very few defects, it would be peeled so as to produce a valuable .thin surface grade veneer. If the log appeared to have many defects, it would be peeled so as to produce a relatively thick, inferior core grade veneer. However, if the lathe was set to produce a thin peel and numerous defects showed up unexpectedly in the interior of the log, much of the peel would be unusable as veneer and would therefore be wasted. On the other hand, if the lathe was set for a thick peel but the interior of the log turned out unexpectedly to be of sufficiently high quality to produce surface grade veneer, much potential production of this highly valuable surface grade veneer was lost.

In changing thickness settings of a veneer lathe three adjustments are necessary, namely (1) a change in the feed rate of the veneer knife into the log; (2) a change in the horizontal spacing between the veneer knife and the roller bar; and (3) a change in the vertical spacing between the roller bar and the knife.

In the past several attempts have been made to solve the problem of reducing the time required to change thickness settings of a veneer lathe. However, no prior art devices suggested for this purpose are capable of making more than one of the above necessary adjustments sufficiently fast to justify economically varying the thickness of peel from a single log. For example, the prior art Cremona US. Pat. No. 3,473,585 discloses an apparatus for changing only the horizontal spacing between the veneer knife and the roller bar. On the other hand, Nagaoka US. Pat. No. 3,349,820 discloses an apparatus suitable only for changing the horizontal feed rate of the knife.

Thus there is still a need for a control system capable of making quickly all of the lathe adjustments necessary to change the thickness of pee] without impairing the dimensional accuracy or quality of the peel.

SUMMARY OF THE INVENTION The present invention overcomes the problems of the prior art in providing a variable thickness control enabling almost instantaneous adjustment of the thickness settings of a veneer lathe to vary the thickness of peel between a predetermined thin setting and a predetermined thick setting. This enables both core grade and surface grade veneer to be peeled from a single log as dictated by the condition of the portion of the log being peeled at any given time.

The thickness control of the invention maximizes the economic value of veneer which can be peeled from a single log.

The control minimizes the amount of production time lost in changing from one thickness setting to another. The control minimizes the amount of waste produced in peeling a log.

The control minimizes the amount of production time lost in changing from one thickness setting to another.

The control also takes most of the guesswork out of grading a log to determine whether to peel it at a thick setting or a thin setting of the lathe.

Furthermore the control is adaptable to existing lathes, making it unnecessary to purchase an expensive new lathe to receive the benefits of the invention.

More specific objects and features of the invention include:

1. means for changing quickly the feed rate of the veneer knife into the log;

2. means for changing quickly the vertical spacing between the roller bar and the veneer knife;

3. means for changing quickly the horizontal spacing between the roller bar and the veneer knife;

4. means for effecting all three of the foregoing changes substantially at the same time;

5. a manually operable remote control for effecting all three changes simultaneously;

6. a remote control including a single control member which effectuates all three adjustments simultaneously.

BRIEF DESCRIPTION OF THE DRAWINGS The foregoing and other objects, features and advantages of the present invention will become more apparent from the following detailed description which proceeds with reference to the accompanying drawings wherein:

FIG. 1 is a schematic view of a veneer lathe incorporating the control system of the present invention;

FIG. 2 is a partial front elevational view of a veneer lathe with portions broken away to illustrate portions of the control system; box

FIG. 3 is a schematic view of a two-speed gear box used as part of the transmission in the system of FIG. 1;

FIG. 4 is a schematic view of a ratio gear box used in conjunction with the two-speed gear box of FIG. 3;

FIG. 5 is a schematic plan view of a first portion of a shifting arrangement for shifting gears in the gear box of FIG. 4;

FIG. 6 is a second portion of the shifting arrangement for shifting gears in the gear box of FIG. 4;

FIG. 7 is a diagram of the air circuit for the control system of FIG. 1;

FIG. 8 is a diagram of the hydraulic circuit for the control system of FIG. 1;

FIG. 9 is a diagram of an electrical circuit for the control system of FIG. 1;

FIG. 10 is a schematic elevational view of the transmission shown in FIGS. 3 through 6; and

FIG. 11 is a partial top view of the veneer lathe of FIG. 2 showing a portion of the horizontal drive for the roller bar.

described with reference to a conventional veneer lathe such as, for example, a Model 244 lathe manufalitiired by the Coe Manufacturing Company of Painesville, Ohio. Such lathes normally do not come equipped with the control system to be described but, in accordance with the invention, they can be readily converted to incorporate such system. Such lathe is typical of a conventional veneer lathe in that it includes a stationary main frame mounting a chuck 12 for rotating a peeler log L in a direction indicated by the arrow 14 in FIG. 1. A veneer knife 16 is mounted on a knife carriage 18 which in turn is mounted on a bed portion of the frame for sliding movement toward and away from the chuck.

The knife carriage 18 is movable in a horizontal direction to feed knife 16 into the log by a motor 20 through a transmission which includes a multiple speed gear box arrangement 22 transmitting motive power through a worm shaft 24 to a nut member 26 on the knife carriage.

The lathealso includes a rotatable roller or pressure bar 28 spaced above-knife 16 for applying a variable pressure to the back side of the veneer V as it is peeled from the log by knife 16. The spacing of roller bar 28 both horizontally and vertically with respect to knife 16 depends on the desired thickness of the veneer peeled from the log. For a relatively thin veneer the roller bar is positioned vertically closer to the knife and horizontally closer to the log than for a thick veneer peel. Thus roller bar 28 is mounted for vertical and horizontal adjustment relative to knife 16. For this purpose the roller bar is mounted on a carriage head or subcarriage 30. The head in turn is mounted on knife carriage 18 in a manner permitting horizontalmovement of the head relative to the carriage 18 and thereby horizontal adjustment of the roller bar 28 relative to the knife. The

head is also mounted on the carriage in a manner permitting vertical adjustment'of the head relative to the carriage 18 and thereby vertical adjustment of the roller bar 28 relative to knife 16.

Referring to FIGS. 1 and 11, the means for moving head 30 and thus roller bar 28 horizontally relative to the knife includes an electric motor 32 driving a worm shaft 34 through a chain-and-sprocket drive 36. The worm shaft 34 extends through a nut 38 forming part of head 30.

' The means for changing the vertical spacing between the roller bar 28 and knife 16 includes a pair of vertically spaced-apart set

screws

40, 41 at each side of the knife carriage threaded through

portions

42, 43 of knife carriage 18 as shown in FIGS. 1 and 2. A portion 44 of carriage head 30 extends between each pair of set screws. Prior to the control system of the present invention, the two set screwscomprised the sole means of determining the vertical adjustment of roller bar 28 relative to knife 16. Naturally this adjustment was time consuming and had to bedone manually.

a a drive chain 48,-a first sprocket 49 on motor drive shaft 50 and a second sprocket 51 on an end portion of the roller bar.

Gear box arrangement 22 includes a two-speed gear box and a so-called decimal gear box 54, with the latter superimposed on the former as shown in FIG. 10.

The decimal gear. box can provide while countel'slnft diffesentgearratiosllhetwo-speedgeu-boxprovldesa.

highmdlowspeednnge.'1hus,togetherthetwogear boxes provide up to 200 different speeds and therefore i the same number of possible thicknesses of peel.

The decimal gear box is shown schematically in FIG. 4. It includes an input shaft 56, output shafi 58 and two

countershafts

60 and 62. Countershaft 60 is on the soshifting fork (not shown) The differential speed.

between the two countershafts resulting from the selected gear ratios on the A and B shafts is transmitted from the countershafts through a train of

gears

61, 63, 65 to pinion gears 69 which thereby rotate output shaft 8.

decimalgear box through an output gear of the twospeed gear box and an input gear 57 of the decimal gear box, such gears being constantly in mesh.

As described thus far, the lathe is of conventional construction and has not included a description of the control system of the invention. With such a conven-' tional lathe an operator could only change the thickness settings of the roller bar and knife as follows: 1. Assuming the gear box arrangement as described, first the engaged gear on the A side and the engaged gear on the B side of'decimal box 54 would be shifted individually and manually back to their neutral positions and a second gear on the A side and a second gear on the B side shifted manually in the necessary direction to give the desired new speed ratio. Furthermore, it would be necessary to manually shift operating lever 81 of the two-speed gear box depending on whether the low or high speed range would be required for the desired thickness setting. Thus the several manual and separate gear-shifting operations were in themselves time consuming to change the rate of feed of knife 16. 2. The desired horizontal spacing of the roller bar relative to knife 16 would be changed according to the new thickness of peel selected through operation of a relatively slow-speed drive from motor 32 to the roller barsubcarriage 30. 3. The operator would manually turn set

screws

40 and 41 to change the elevation of roller bar head 30 relative to knife carriage 18, and thereby the spacing of roller bar 28 relativeto the knife as dictated by the changed thickness requirements. Naturally, the foregoing three separate manual steps are tedious and time consuming. understandably, they gave rise to the practice of peeling a single constant thickness of veneer for as long as possible without changing thickness settings and at least through the peeling of one entire log. Otherwise it would not be economical to shut down production to change from a thick to a thin setting or from a thin to a thick setting every time a change in quality of the wood in a single log was observed. Although the foregoing prior practice is uneconomical and results in much wastage, in fact it is more economical than shutting down frequently to change thickness settings.

Control System The control system of the invention comprises essentially four elements. A first of these four elements is a means indicated generally at 83 for shifting gear boxes 22 quickly from one preselected speed ratio to another.

The second of these elements comprises a means indicated generally at 85 for changing quickly the horizontal spacing between roller bar 28 and knife 16.

The third of these elements includes means indicated generally at 87 for changing quickly the vertical spacing between the roller bar and knife.

Finally the fourth element of the system is a remote control means indicated generally at 89 for operating all three of the aforementioned elements substantially at the same time from a control station remote from such elements. A detailed description of each of the above four elements follows.

Shifting Arrangement for Gear Boxes A series of conventional shifting forks, one for each set of sliding gears, shifts each of the sliding gear sets 64 of gearbox 54 to the right or left on

splined countershafts

60, 62. From FIG. 4 it will be apparent that only one set of gears on each of The A and B sides of the decimal gear box can be in mesh with one of the gears on input shaft 56 at any given time. Yet one gear on each side of the box must be engaged to transmit power to the output shaft. Thus one shifting fork on each of the A and B sides is operated at a time.

Each shifting fork is shifted to shift a gear set right or left in FIG. 4 by a pivotal shifting crank, the pivotal post portion 90 of each of which is shown in FIGS. 5 and 6. Each post extends upwardly through two shifting levels of the decimal gear box including a lower shifting level 92, shown in FIG. 5, and an upper shifting level 94, shown in FIG. 6. The upper level is superimposed on the lower level and both levels in turn are superimposed on the interior of the decimal gearbox in the manner shown in FIG. 10.

Each shifting level of gear box 54 has an A and a B side corresponding to The A and B sides of the shiftable gear sets shown in FIG. 4. Each post 90 of the A and B sides of each of the upper and lower shifting levels is pivoted in a clockwise or counter clockwise direction to shift its corresponding gear set to the right or left by a shift lever 96.

Each of the five shift levers 96 on each of the A and B sides of each shifting level can be selectively connected by a removable pin 98 to one of the four

shift bars

100, 104, 108, 110 common to each of the four sets of five levers. Each shift bar can be shifted lengthwise in opposite directions to shift a connected lever to the right or left and thereby shift a corresponding fork and sliding gear set.

Air cylinders

102, 106, 112 and 114 shift the shift bars 100, 104, 108, 110, respectively, in the desired direction to engage the selected gears on the A and B sides of the decimal gear box. However, it is important that only one of the two

shift bars

100, 108 on the A side and one of the two

shift bars

104, 110 on the B side be shifted from its neutral position at a timeso that only one gear oneach side is engaged at any time. Each of the four

shift bars

100, 104, 108, 110 is biased to a neutral position, as shown, by a centering spring 1 16.

Each of the four

air cylinders

102, 106, 112 and 114 is a double-acting cylinder capable of reciprocating its shift bar to the right or left from its neutral position. However, in practice it is frequently desirable to prevent the shifting movement of a given shift bar in one of its two directions, depending on the thicknesses selected, so as to prevent inadvertent selection of a wrong gear ratio. For this purpose a pair of

stop pin holes

118, 119 is provided in each shift bar, one positioned on each of the opposite sides of an abutment member 120 when the shift bar is spring-centered to its neutral position. By inserting a stop pin (not shown) through one of the pin holes 118, 119, shifting movement of the shift bar in one of its two directions of movement is prevented through abutment of the stop pin with the abutment member. Thus, for example, if the pin is inserted in hole 118 of shift bar 100 in FIG. 5, cylinder 102 cannot shift the bar toward the right from its neutral position. The converse would be true if the stop pin is inserted in hole 119.

A fifth double-acting air cylinder 122 is mounted on the side of the two-speed gear box 54. The piston rod of this cylinder is connected to clutch-operating lever 81 to shift the two-speed gear box from its high speed range to its low speed range and back again. A solenoid valve 124 controls the direction of air flow to cylinder 122.

Operation of the four shift bar operating cylinders I 102, 106, 112, 114 is controlled by three air valves each. Cylinder 102 is controlled by a pair of two-position on-off valves 102a, l02b and a directional control valve 1020. Cylinder 106 is controlled by the pair of onoff valves 106a, l06b and the directional control valve 106c. Cylinder 112 is controlled by the pair of on-off valves 112a, 112b and the directional control valve 1120. Cylinder 114 is controlled by the pair of on-off valves 114a, 114b and the directional control valve l 140.

As will be clear from FIG. 7, valves 102e, 1060, and 1120 and 1140 control the direction of movement of their respective cylinders and thus the direction of shifting of the slidable gears. These valves are manually operated and for convenience may be located at a remote operators station.

With reference to FIGS. 5, 6 and 7, air valves 102a and b, 106a and b, 112a and b and 114a and b are operated by

cams

125, 126 fixed to each shaft bar. The two cams on each A shift bar operate the two air valves a and b for the other A shift bar. Similarly the two cams on each B shift bar operate the a and b valves for the other B shift bar. This arrangement ensures that one of the two air cylinders on each of the A and B sides of the decimal gear box returns to its centered neutral position before the other of such two cylinders can shift from its neutral position, thereby preventing the engagement of two A or two B gears simultaneously and resulting damage to the gear box.

In FIG. 7 solenoid valve 124 is shown in a position for shifting clutch cylinder 122 to the left to thereby shift the two-speed gear box to its low speed range for a relatively thin peel. The a and b valves for cylinders 102 and..l06 are shown in positions permitting air flow through their respective valves 102c and l06c to their shift bar cylinders. 102 and .106 in a manner so that cylinder 102 and thus its'shift baris shifted toward the left and in'a manner so that cylinder 106 and its shift bar are shifted toward the right. At the same time, the a and b valves for

cylinders

112 and 114 are shown in positions blocking flow to such cylinders. The latter cylinders remain centered in their inactive positions until lower shift bars 100, 104 permit their respective air valves 1120, 112b, 1140, 114b to open through return of

cylinders

102 and 106 to their neutral positions. 6

From the description thus far, it will be clear that A shift bars 100 and 108 shift the same five sets of gears inthe decimal gear box. Similarly, B shift bars 104' and l shift the same five sets of gears on the B side of the decimal gear box. Each one of the ten shift levers 96 for each shifting level may be said to have two positions which are numbered 1 through 10 on the A side and 1 through 10 on the B side of each shifting level in each of FIGS. 5 and 6. Thus each lever 96 may be designated by a letter and numbers corresponding to the position it I occupies in its level of the gear box, such as lever Al-2, A7-8, 83-4, 89-10, etc., as shown in FIGS. 5 and 6.

The desired thin and thick peels for a given run may require, for example, that one of the levers A1-2 be moved to its A1 position fora thin peel and that one of levers A5-6 be moved to its A6 position for a thick peel. Since only one A lever can be connected to the

same shift bar

100 or 108 at a time to prevent shifting more than one'A gear at a time, it is necessary to provide two shift bars for the A side of the gear box. In the example, lever A1-2 would be connected by a pin to one A shift bar, and lever A5-6 would be pinned to the other A shift bar. Forthesame reason, two B shift bars are provided.

Horizontal Adjustment of Roll Bar The illustrated means 85 for changing the spacing between roller bar 28 and knife 16 in the direction of movement of the knife, or horizontally, includes a modification of the transmission 36 to give a high and low speed drive for the roller bar. Referring to FIGS. 1

and 11, transmission 36 from electric motor 32 includes a drive shaft 130 from the motor provided with two pneumatic clutches, including a high speed clutch 132 and a low speed clutch 134. When the high speed clutch is engaged and low speed clutch disengaged, the drive is through chain-and-sprocket drive 136, countershaft 138, cross shaft 139 and

bevel gears

140, 141

' to worm gear 34 which drives the roller bar ahead at a relatively high speed to its desired position relative to the knife. This desired position can be readily deterrowhead 143a. For a thick peel the head is moved in the reversedirection through reversal of motor 32 until marker 142b is aligned with arrowhead 1430.

When a fine adjustment of the pressure of roller bar 28 against the veneer is desired, high speed clutch 132 is disengaged and low speed clutch l34is engaged to drive the worm shaft through chain-andsprocket drive 144, countershaft 148, gears 145, 146, cross shaft and worm shaft 139. This provides a very slow speed movement of the head 30, permitting the desired fine adjustment of roller bar pressure.

Normally, when the roller bar is in a predetermined adjusted position, both high speed clutch 132 and low speed clutch 134 are engaged. With both clutches engaged they serve as a brake to hold the roller bar in its predetermined adjusted position relative to the knife.

The air circuit which controls operation of the pneumatic clutches is shown in the air circuit diagram of FIG. 7. Air under pressure from a source 148 is supplied through

lines

149, 150 to a pair of normally

open solenoid valves

152, 154 to the high and low speed clutches so that both clutches remain engaged simultaneously. When it is desired to operate the high speed clutch, the low speed clutch is disengaged by energizing solenoid valve 154 to shift it to the left in FIG. 7, through appropriate electrical control means to be described. Conversely, when a drive is desired through the low speed clutch, the high speed clutch is disengaged by energizing solenoid valve 152 to block the air supply to the high speed clutch.

It will be appreciated that a variable speed electric or other motor or other type of variable speed transmission could be used in place of the two-speed pneumatic clutch-operated transmission described, to give 'the desirable multiple speed drive for the horizontal roller bar feed.

Vertical Adjustment of Roller Bar A quick vertical adjustment of roller bar 28 is made by vertical adjustment means 87 which includes a pair of upright

hydraulic cylinders

160, 161, both of which are shown in FIG. 8 and one of which is shown in FIGS. 1 and 2. One of such pair of cylinders is mounted at each of the opposite sides of roller bar head 30 as shown in FIG. 2 within carriage 18. Thus each such cylinder moves horizontally with the knife carriage.

. Each cylinder includes a ram 162 connected at its outer end to a yoke member 163 which abuts a lower surface of an abutment portion 164 of roller bar head 30. Head 30 also includes an upper abutment portion 166. The upper adjustable stop screw 40 of carriage 18 is positioned above upper abutment portion 166 of head 30. The lower adjustable stop screw 41 of carriage 18 is positioned beneath lower abutment portion 164 of head 30.

The stroke of the rams 162 of cylinders and 161 are such that when the rams are extended, head 30 is raised until abutment portion 166 contacts the lower end of upper stop screw 40 to determine the upper limit position of roller bar 28. Conversely, when rams 162 are retracted, head 30 is lowered until lower abutment portion 164 contacts the upper end of lower stop screw 41 to determinethe lower limit position of roller bar.

28. The upper and lower limit positions of the roller bar can be changed through threaded adjustment of the upper and lower stop screws.

FIG. 8 shows the hydraulic control circuit diagram for controlling operation of the two

lift cylinders

160, 161. Hydraulic fluid is supplied under pressure from a pump 168 driven by an electric motor 169 through a supply line 170 and branch lines 171, 172 to upper ends of the cylinders or through alternate supply line 173 and branch lines 174, 175 to the lower ends of the cylinders. A two-position solenoid valve 176 in a first position shown directs pressure fluid through lines 171 and 172 to the upper ends of the lift cylinders to retract the same. In the second position of valve 176, supply fluid is directed through

lines

173, 174 and 175 to the lower ends of the lift cylinders to extend the same. In either case, return flow is through return line 178 to sump 179.

FIG. 8 also shows the hydraulic circuit driving the hydraulic motor 46 which rotates the roller bar 28. Such circuit includes a pump 180 driven by the same electric motor 169 that drives pump 168. Pump 180 supplies pressure fluid through supply line 181 to hydraulic motor 46. Return flow is through line 182 back to sump.

Remote Control The remote control means 89 for operating the three adjustments described is shown in FIGS. 1 and 9. The control, located at a control station remote from the three adjustment means, includes a first toggle switch control member T81 and a second toggle switch control member TS2. The single member toggle switch T82 is used to make all three thickness change settings described. The single member toggle switch TS] is used only for making slow-speed, fine pressure adjustments of the roller bar against the veneer being peeled.

As shown in the electrical diagram of FIG. 9, moving toggle TSl in one direction, or upward in FIG. 9, energizes solenoid valve 152 to disengage high speed clutch 132 and energize motor 32 in a forward direction, thereby permitting low speed clutch 154 to drive roller bar head 30 slowly forward against the veneer.

Moving toggle TS1 downward again energizes solenoid valve 152 to disengage the high speed clutch and permit the low speed clutch to drive the roller bar head slowly, but this time in a reverse direction through activation of motor 32 in reverse to back off the roller bar from the veneer. Release of toggle TSl returns it to its centered neutral position.

Moving TS2 upward in FIG. 9 drives roller bar motor 32 in a forward direction, and at the same time energizes relay R1. Relay R1 closes the three switches R1. Closing of one of these three switches energizes the A side of solenoid valve 124 to cause air cylinder 122 to shift the two-speed gear box into its low speed range for a relatively thin peel. At the same time, closing of a second of the three switches R1 energizes solenoid valve 154 to disengage low speed clutch 154, permitting high speed clutch 152 to drive roller bar head 30 forward at a fast speed for quick readjustment of the horizontal position of the roller bar relative to knife 16. When the desired horizontal adjustment of the roller bar is made, the release of toggle TS2 returns it to its neutral position, thereby de-energizing solenoid valve 154 and re-engaging the low speed clutch to lock the roller bar in its readjusted position.

With TS2 in its upper position as mentioned, the third of the three switches R1 energizes the A side of solenoid valve 176 to direct hydraulic flow to the upper ends of

lift cylinders

160, 161, thereby retracting the cylinders and lowering the roller bar to its predetermined lower limit position relative to knife 16.

All three of the above adjustments occur simultaneously. As soon as they are made, toggle switch T82 is released and the lathe is reset and ready to produce a thin peel. Only a few seconds before, the lathe was set up for producing a thick peel.

With toggle switch TS2 returned to its neutral position, the lathe remains set for producing a predetermined thin peel until the same toggle switch is moved downward to change the lathe settings for making a predetermined thick peel.

By moving toggle T82 downward in FIG. 9, it activates roller bar motor 32 in a reverse direction and energizes a second relay R2. Relay R2 closes three cor- I responding switches R2 simultaneously to energize the B side of solenoid 124, energize solenoid valve 154 and energize the B side of solenoid valve 176. The B side of solenoid valve 124 causes air cylinder 122 to shift the two-speed gear box into its high speed range, thereby feeding the knife into the log at a fast speed to produce a thick peel. At the same time, solenoid valve 154 again de-energizes low speed clutch 154, permitting high speed clutch 152 to drive worm shaft 34 in a reverse direction to back off the roller bar to its thick setting as detemiined by line-up of the marker l42b with the arrowhead 1430 in FIG. 11. At the same time, the B side of solenoid valve 176 directs hydraulic flow to the lower ends of

lift cylinders

160, 161 to elevate roller bar 28 to its upper limit position. With this completed,

toggle switch T82 is released, permitting it to return to Operation In practice it has been found that the entire readjustment operation as described can be accomplished in only a few seconds. This time factor makes it feasible.

for the first time to change thickness settings while peeling a single log, depending on the condition of the wood at-the surface being peeled at any given time. Thus, for example, if an outer portion of the log is relatively free of defects, the lathe can be quickly adjusted for producing a thin, high quality, valuable surface grade veneer relatively free of defects. However, if as the peeling progresses, a defective portion of the log is encountered, the lathe can be quickly adjusted for a thick peel merely by shifting toggle TS2 downwardly. Rotation of the log thereafter will produce a thick core grade veneer. The thick peel can be continued until such time as the quality of the wood at the surface of the log improves sufficiently to again peel a thin surface grade veneer. Then the lathe can be adjusted quickly back to its thin setting by shifting toggle TS2 upwardly from its neutral position.

Of course, it will be appreciated that the exact dimensions of the thin and thick peels that are produced through operation of toggle TS2 are determined by the gear ratios selected in the two

gear boxes

54, 70. The selection of necessary gear ratios to produce the desired dimensions of thick and thin peels are made from a chart usually provided by the lathe manufacturer. From the chart, the necessary position dimensions can be selected.

To illustrate, let us assume that production schedul for a given mill shift require a surface grade veneer of 0.032 of an inch and a core grade veneer of 0.084 of an inch. The chart reveals that for the required thin veneer, the two-speed box must be shifted to its low speed range, and one of the A shift levers must be shifted to position A6 and one of the B levers must be shifted toposition B1 in the decimal gear box. The

same chart shows thatffor the desired thick peel, the two-speed gear box must be shifted to its high speed range, and one of the A levers must be shifted to position A1 and one of the B levers must be shifted to position B2.

To'accomplish the foregoing, lever A5-6 in lower shift level 92 of the decimal gear box is pinned to shift bar 100. A stop pin is inserted in stop hole 119 of the same shift bar so that such bar can only be shifted toward the right in FIG. 5 to shift lever A5-6 to its A6 position. Air valve 1020 is positioned so that cylinder 10: will shift toward the right in FIG. 5 when the A side of solenoid valve 124 in FIG. 7 is energized to shift the two-speed gear box into its lowrange.

Similarly, shift lever 81-2 at the lower shifting level 92 is pinned to shift bar 104, and a stop pin is inserted through stop pin opening 1 18 of such shift bar so that it can only shift in a direction to position lever 81-2 to its Bl position. Air valve 106c is positioned so that it will cause cylinder 106 to shift left in FIG. 5 when the A side of solenoid valve 124 is energized to cause cylinder 122 to shift the two-speed gear box into its low speed range. The lower shifting level is now set up to produce the desired thin peel.

- that air cylinder 112 will shift bar 108 toward the left and lever A1-2 to its Al position when the B side of solenoid valve 124 in FIG. 7 is energized to shift the two-speed box into its high speed range. 0

Similarly lever B1-2 in the upper shifting level is pinned to shift bar 1 10, and a stop pin is inserted in stop pin opening 119 of such bar so that lever Bl-2 can be shiftedonly to its B2 position. Air valve 1 14c is set so as to cause cylinderll4 to shift bar 110' toward the right and thus shift lever 81-2 to its B2 position when the B side of solenoid valve 124 is energized to shift the twospeed box into its low speed range.

With the shifting levels set up as described, an up- A ward movement of toggle TS2 will automatically set the lathe to peel veneer having a thickness dimension of 0.032 of an inch. Similarly, a downward movement of toggle TS2 will automatically readjust'the lathe to peel veneer having a thickness dimension of 0.084 of an inch. Operation of

cylinders

102 and 106 to produce the thin peel automatically prevent operation of cylin-' ders 1 12 and 114 by closing the a and b air valves of the latter cylinders until the former cylinders return to their neutral positions. The converse occurs when cylinders l 12 and l 14 are operated.

Having illustrated what is now a preferred embodiment of our invention, it should be apparent to those having skill in the art that the same permits of modificaat various predetermined speeds, a roller bar positioned with respect to the knife for applying a pressure to a back surface of veneer as it is peeled from'the log, means mounting the roller bar for movement with the knife toward the log, said roller bar mounting means also mounting the roller bar for movement in the direction of knife movement independently of knife movement and for movement in a direction normal to the direction of knife movement, and means for moving said roller bar relative to said knife in the direction of knife movement,

a control system for quickly changing settings of the veneer lathe to peel different thicknesses of veneer from the same log or from different logs comprismg:

means for shifting quickly said multiple speed trans mission from a first predetermined speed to a second predetermined speed to change the speed of movement of said knife into said log,

v said means for moving said roller bar relative to said knife in the direction of knife movement including variable speed means for moving said roller bar at a first fast speed for quick adjustmentof said roller bar relative to said knife and at a second slow speed for adjusting the pressure of the roller bar against the back of the veneer.

2. Apparatus according to claim 1 including remote manual control means for operating said shifting means and said variable speed means from a position remote from said shifting and variable speed means.

3. Apparatus according to claim 1 including means for changing quickly the spacing between said roller bar and said knife in a direction normal to the direction of knife travel.

4. Apparatus according to claim 3 including remote manual control means for operating said shifting means, said variable speed means and said spacing changing means from a control station remote from all three of said means.

5. Apparatus according to claim 2 wherein said remote control means includes a single control member for operating said shifting means and for actuating said variable speed means to move said roller bar at said first fast speed.

6. Apparatus according to claim 4 wherein said remote control means includes a single control member for operating said shifting means, for actuating said variable speed means to move said roller bar at said fast speed and for operating said spacing changing means.

7. A control system for quickly adjusting a veneer lathe to change the thickness of peel from f a -log, wherein said lathe includes means for rotating a log, a knife movable into the log, and a roller bar spaced from the knife for applying pressure to the back side of veneer as it is peeled from the log, said control system including:

means for quickly changing the speed of movement of said knife into said log, and means for quickly changing the spacing between the cutting edge of said knife and said roller bar in both the direction of knife movement and in a direction normal to the direction of knife movement. 8. A system according to claim 7 including manually operable remote control means for selectively operating said knife speed changing means and said roller bar spacing changing means from a position remote from both said changing means.

9. A system according to claim 8 wherein said remote control means includes a single control member for effecting all three changes simultaneously.

10. In a veneer lathe including means for mounting and rotating a log to be peeled, a knife having a cutting edge for peeling said log, a roller bar adjacent the cutting edge of said knife for applying a pressure to a back surface of veneer at the log as it is peeled from the log, knife feed means for moving the knife and roller bar together toward the log, and means providing multiple thickness settings for said lathe so that veneer of at least several different predetermined multiple thicknesses can be peeled,

adjustment means for quickly changing the thickness settings of said lathe between a first thin setting and a second thick setting so that both surface and core grade veneer can be peeled from a single log, said adjustment means comprising: means for changing quickly the feed rate of said knife between a first preset slow rate for a thick peel and a second preset fast rate for a thin peel,

means for changing quickly the spacing between said roller bar and said knife cutting edge in the direction of knife movement between a first predetermined maximum spacing for a thick peel and a second predetermined minimum spacing for a thin peel,

means for changing quickly the spacing between said roller bar and said knife cutting edge in a direction normal to the direction of knife movement between a first preset maximum spacing for a thick peel and a second preset minimum spacing for a thin peel,

and manually operable control means for actuating all three of said changing means and thereby effecting all three of said changes simultaneously.

11. Apparatus according to claim 10 including means for changing slowly the spacing between said roller bar and said knife cutting edge in the direction of knife movement for fine adjustment of the back pressure of said roller bar against the veneer.

12. Apparatus according to claim 11 wherein said means for changing the spacing between said roller bar and said knife cutting edge quickly and slowly in the direction of knife movement include a constant speed motor and a multi-speed drive transmission means interconnecting said motor and said roller bar, said transmission means including a normally engaged highspeed transmission path including a first clutch means and a normally engaged low-speed transmission path including a second clutch means arranged such that when both said clutching means are engaged, said transmission means is locked to prevent the transmission of driving force to said roller bar, said control means including means for selectively disengaging either one of said first and second clutch means so that said transmission path having the engaged one of said clutch means transmits driving force to said roller bar.

13. Apparatus according to claim 10 wherein said knife feed means includes a drive means and transmission means for transmitting motive power from said drive means to said knife, said means providing multiple thickness settings for said lathe including a multiple speed gear box means having multiple selectively engageable shiftable gears providing a multiplicity of different output speeds for feeding said knife into a log at different feed rates, said means for changing quickly the feed rate of said knife including means for programming two different gear combinations for engagement from said multiple shiftable gears to select alternatively two different output speeds from said multiplicity of output speeds, and means operable automatically upon actuation of said control means for shifting preselected ones of said gears of said gear box means to provide selectively one or the other of said gear combinations and therefore one or the other of said two selected output speeds and knife feed rates.

14. A thickness control for a veneer lathe having a knife which can be fed into a rotating log at a multiplicity of different speeds to peel different thicknesses of veneer by a knife drive means including a multiplespeed gear box having an input shaft, an output shaft and first and second countershafts in driving engagement with said output shaft through differential gearing, said countershafts being parallel to said input shaft with a plurality of shiftable gears on each countershaft selectively engageable with gears on said input shaft for transmitting motive power at a multiplicity of different rotational speeds to said output shaft, and a separate gear shifter means for each said shiftable gear on each said countershaft operable to shift an associated said shiftable gear in opposite directions along its said countershaft, said thickness control comprising:

first and second pairs of shift bar means,

said first pair including first and second shift bar means each selectively connectable to any one of said gear shifter means for said first countershaft for shifting selected shiftable gears on said first countershaft from a neutral position in either of opposite directions into engagement with said input shaft gears,

said second pair including third and fourth shifter bar means each selectively connectable to any one of said gear shifter means for said second countershaft for shifting selected shiftable gears on said second countershaft from a neutral position in either of opposite directions into engagement with said input shaft gears,

a separate shifter bar actuating means for each said shifter bar means for moving each said shifter bar means independently of the others of said shifter bar means selectively in either of opposite directions for shifting a connected said shiftable gear in a corresponding direction, and control meansfor selectively controlling the operation of said four shifter bar actuating means including:

a manually selective directional control means for each said shifter bar actuating means for determining the direction of .movement of an associated said shifter bar means and thus the direction of shifting of a connected shiftable gear means upon operation of the associated said actuating means,

, on-off control means for each said shifter b'ar actuating means operable automatically to prevent the operation of the actuating means for one said shifter bar means of a pair when the actuating means for the other said shifterbar means of the same said pair is actuated,

and manually operable speed shifting means movable to a first position for operating a said actuating means for one said shifter bar means of each said pair shifter bar means to provide a preselected first gear ratio and output speed and movable to a second position for operating a said actuating operable in said first position to shift said two-speed means for the other said shifter bar means of each gear box to its low-speed range and thereby provide a preselected slow output speed and thin peel and operable in said second position to shift said two-speed gear 7 box to its high-speed range and thereby provide a preselected high output speed and thick peel of veneer.

16. A thickness control according to claim 14 wherein said shifter bar means include four shifter bars mounted for reciprocation, saidactuating means for each shifter bar including a double-acting fluid-actuated cylinder, said directional control means including a manually positionable two-position directional controlvalve for each said cylinder, said on-offcontrol means including a pair of on-off control valves for each cylinder, one in a fluid passage leading to each side of the associated said cylinder, each said on-off valve of a cylinder for one shifter bar of a pair being movable to an off position upon movement of the other shifterbar of a pair from a neutral position to a gear-shifting position.

17. A thickness control according to claim 16 wherein said control means includes a releasable stop said speed-shifting means.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,680,613 Dated August 1 1972 Inventods) Curtice F. Daniels and Curtice F. Daniels Jr.

It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In the references, "Class 14/213" should be --l44/2l3. Column 4, line 4 "while countershaft" should be -lO0-. Column 4, line 15, after (not shown) insert --into mesh with one of two sets of stationary gears on the input shaft..

Column 5, line 33, "The" should be -the-. Column 5, line 51, "The" should be -the---.-- Column 9, line 60, "horizOntal" should be -horizontal--. Column 15, line 21 (claim 14) after "pair" insert of.

Signed and sealed this 9th day of January 1973.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents FORM P0405) (10'69) USCOMM DC 60376 P69 a U.5 GOVERNMENT PRINTING OFFICE: I959 O366'334

Claims

1. In a veneer lathe including means for rotating a log to be peeled, means mounting a knife for movement into the log, means including a drive motor and multiple speed transmission for moving the knife into the log at various predetermined speeds, a roller bar positioned with respect to the knife for applying a pressure to a back surface of veneer as it is peeled from the log, means mounting the roller bar for movement with the knife toward the log, said roller bar mounting means also mounting the roller bar for movement in the direction of knife movement independently of knife movement and for movement in a direction normal to the direction of knife movement, and means for moving said roller bar relative to said knife in the direction of knife movement, a control system for quickly changing settings of the veneer lathe to peel different thicknesses of veneer from the same log or from different logs comprising: means for shifting quickly said multiple speed transmission from a first predeterMined speed to a second predetermined speed to change the speed of movement of said knife into said log, said means for moving said roller bar relative to said knife in the direction of knife movement including variable speed means for moving said roller bar at a first fast speed for quick adjustment of said roller bar relative to said knife and at a second slow speed for adjusting the pressure of the roller bar against the back of the veneer.

7. A control system for quickly adjusting a veneer lathe to change the thickness of peel from a log, wherein said lathe includes means for rotating a log, a knife movable into the log, and a roller bar spaced from the knife for applying pressure to the back side of veneer as it is peeled from the log, said control system including: means for quickly changing the speed of movement of said knife into said log, and means for quickly changing the spacing between the cutting edge of said knife and said roller bar in both the direction of knife movement and in a direction normal to the direction of knife movement.

8. A system according to claim 7 including manually operable remote control means for selectively operating said knife speed changing means and said roller bar spacing changing means from a position remote from both said changing means.

10. In a veneer lathe including means for mounting and rotating a log to be peeled, a knife having a cutting edge for peeling said log, a roller bar adjacent the cutting edge of said knife for applying a pressure to a back surface of veneer at the log as it is peeled from the log, knife feed means for moving the knife and roller bar together toward the log, and means providing multiple thickness settings for said lathe so that veneer of at least several different predetermined multiple thicknesses can be peeled, adjustment means for quickly changing the thickness settings of said lathe between a first ''''thin'''' setting and a second ''''thick'''' setting so that both surface and core grade veneer can be peeled from a single log, said adjustment means comprising: means for changing quickly the feed rate of said knife between a first preset ''''slow'''' rate for a thick peel and a second preset ''''fast'''' rate for a thin peel, means for changing quickly the spacing between said roller bar and said knife cutting edge in the direction of knife movement between a first predetermined ''''maximum'''' spacing for a thick peel and a second predetermined ''''minimum'''' spacing for a thin peel, means for changing quickly the spacing between said roller bar and said knife cutting edge in a direction normal to the direction of knife movement between a first preset maximum spacing for a thick peel and a second preset minimum spacing for a thin peel, and manually operable control means for actuating all three of said changing means and thereby effecting all three of said changes simultaneously.

12. Apparatus according to claim 11 wherein said means for changing the spacing between said roller bar and said knife cutting edge quickly and slowly in the direction of knife movement include a constant speed motor and a multi-speed drive transmission means interconnecting said motor and said roller bar, said transmission means including a normally engaged high-speed transmission path including a first clutch means and a normally engaged low-speed transmission path including a second clutch means arranged such that when both said clutching means are engaged, said transmission means is locked to prevent the transmission of driving force to said roller bar, said control means including means for selectively disengaging either one of said first and second clutch means so that said transmission path having the engaged one of said clutch means transmits driving force to said roller bar.

14. A thickness control for a veneer lathe having a knife which can be fed into a rotating log at a multiplicity of different speeds to peel different thicknesses of veneer by a knife drive means including a multiple-speed gear box having an input shaft, an output shaft and first and second countershafts in driving engagement with said output shaft through differential gearing, said countershafts being parallel to said input shaft with a plurality of shiftable gears on each countershaft selectively engageable with gears on said input shaft for transmitting motive power at a multiplicity of different rotational speeds to said output shaft, and a separate gear shifter means for each said shiftable gear on each said countershaft operable to shift an associated said shiftable gear in opposite directions along its said countershaft, said thickness control comprising: first and second pairs of shift bar means, said first pair including first and second shift bar means each selectively connectable to any one of said gear shifter means for said first countershaft for shifting selected shiftable gears on said first countershaft from a neutral position in either of opposite directions into engagement with said input shaft gears, said second pair including third and fourth shifter bar means each selectively connectable to any one of said gear shifter means for said second countershaft for shifting selected shiftable gears on said second countershaft from a neutral position in either of opposite directions into engagement with said input shaft gears, a separate shifter bar actuating means for each said shifter bar means for moving each said shiFter bar means independently of the others of said shifter bar means selectively in either of opposite directions for shifting a connected said shiftable gear in a corresponding direction, and control means for selectively controlling the operation of said four shifter bar actuating means including: a manually selective directional control means for each said shifter bar actuating means for determining the direction of movement of an associated said shifter bar means and thus the direction of shifting of a connected shiftable gear means upon operation of the associated said actuating means, on-off control means for each said shifter bar actuating means operable automatically to prevent the operation of the actuating means for one said shifter bar means of a pair when the actuating means for the other said shifter bar means of the same said pair is actuated, and manually operable speed shifting means movable to a first position for operating a said actuating means for one said shifter bar means of each said pair shifter bar means to provide a preselected first gear ratio and output speed and movable to a second position for operating a said actuating means for the other said shifter bar means of each said pair to provide a preselected second gear ratio and output speed.

15. A thickness control according to claim 14 wherein said knife drive means includes a two-speed gear box connected in tandem with said multiple speed gear box, said speed shifting means including means operable in said first position to shift said two-speed gear box to its low-speed range and thereby provide a preselected slow output speed and thin peel and operable in said second position to shift said two-speed gear box to its high-speed range and thereby provide a preselected high output speed and thick peel of veneer.

16. A thickness control according to claim 14 wherein said shifter bar means include four shifter bars mounted for reciprocation, said actuating means for each shifter bar including a double-acting fluid-actuated cylinder, said directional control means including a manually positionable two-position directional control valve for each said cylinder, said on-off control means including a pair of on-off control valves for each cylinder, one in a fluid passage leading to each side of the associated said cylinder, each said on-off valve of a cylinder for one shifter bar of a pair being movable to an off position upon movement of the other shifter bar of a pair from a neutral position to a gear-shifting position.

17. A thickness control according to claim 16 wherein said control means includes a releasable stop means for each shifter bar operable when engaged to selectively prevent the movement of said shifter bar in either direction from a neutral position and thereby operable to determine which said shifter bar of a pair is operated in each of the two different speed modes of said speed-shifting means.