US3040791A

US3040791A - Log steadying apparatus for veneer lathes

Info

Publication number: US3040791A
Application number: US816931A
Authority: US
Inventors: Leonard J Fauchon
Original assignee: Individual
Current assignee: Individual
Priority date: 1959-05-29
Filing date: 1959-05-29
Publication date: 1962-06-26
Anticipated expiration: 1979-06-26

Description

June 1962 1.. J. FAUCHON LOG STEADYING APPARATUS FOR VENEER LATHES 3 Sheets-Sheet 1 Filed May 29, 1959 J nvvsmlz LEONARD J. FAUCHON June 26, 1962 L. J. FAUCHON 4 791 LOG STEADYING APPARATUS FOR VENEER LATHES Filed May 29, 1959 5 Sheets-Sheet 2 Illllllllllllll" Alva/r0 2 LEONARD J. FAUCHON June 26, 1962 L J FAUCHON 3,040,791

LOG STEADYING APPARATUS FOR VENEER LATHES Filed May 29, 19 59 5 Sheets-Sheet s n3 5%.. 4 5 u I robbx mm I .i..... Q I Z' /xl. n9 Nn. ET J mm H mm. m 5 PI:

LEONARD United rates Fatent Q 3,940,791 LOG STEADYENG APPARATUS FUR VENEER LATHE Leonard E. Fauchon, 1697 Bur-tie St, Port Alberni, British Columbia, Canada Filed May 29, 1959, Ser. No. 816,931 9 Claims. (Ci. 1442ll) This invention relates to apparatus for continuously steadying a log being turned and peeled in a rotary veneer lathe enabling veneer to be cut uniformly from the log.

In the manufacture of veneer, the veneer is usually cut from the log as the latter is turned in a veneer lathe, the lathe carriage being advanced by means of feed screws towards the log causing the veneer lathe knife to peel a predetermined thickness of veneer therefrom. The log is supported axially in the lathe by means of chucks which engage the log at either end thereof. During this operation, the log is subjected to two pressures, namely, the longitudinal pressure applied by the lathe, and the transverse pressure exerted on the log by the knife. These two pressures cause the centre of the log to spring outwardly and upwardly from the knife, thus causing in efiect an increase in the diameter at the centre of the log compared to the diameter at the ends of the log. As the log diminishes in size, it tends further to spring, thus making the veneer thinner in the centre of the log although still maintaining the desired thickness at the ends of the log. In some cases, due to the pressure exerted on the log by the lathe, it will waver causing, in turn, uneven veneer. Whenever springing or wavering of the log occurs, it is necessary to stop the cutting operation and discharge the log from the lathe. Since wavering and springing of the log often occurs while the log core is still of a relatively large diameter, it will be appreciated that considerable wastage can occur.

It is an object of this invention therefore to provide apparatus which will steady a log being peeled in a veneer lathe, thus preventing springing and wavering of the log and enabling veneer to be cut uniformly therefrom down to a very small core.

The present invention contemplates the provision of apparatus comprising a carrier pivotally mounted for movement towards and away from a log in the lathe, and means in the carrier for frictionally engaging the log to apply a force thereto substantially equal and opposite to the force exerted on the log 'by the cutting knife of the veneer lathe.

The invention will now be further described in connection with the accompanying drawings, which show by way of example, one embodiment of the invention.

In the drawings:

FIGURE 1 is a plan view,

FIGURE 2 is an elevation partly in section taken along the line 2-2; of FIGURE 1,

FIGURE 3 is a detailed sectional view taken on the line 33 of FIGURE 2,

FIGURE 4 is a detailed sectional view taken on the line 4-4 of FIGURE 2.

FIGURE 5 is a diagrammatic view of the hydraulic control system, and

FIGURE 6 is a schematic circuit diagram of the associated electrical controls.

Referring to FIGURES 1 and 2 of the drawings, 10 represents a rotary veneer lathe and is designated generally by the reference 19. Since this type of lathe is very well known in the art, no further description of its construction and operation is deemed necessary herein and only sufiicient thereof is shown to enable the invention to be understood. The lathe includes spaced and aligned chucks 12 which are adapted to grip the ends of a log 14 mounted 3,848,781 Patented June 26, 1962 therebetween. The chucks 12 are driven in usual manner from any suitable source of power, not shown, to rotate the log 14.

A knife 16 is adjustably mounted in and projects upwardly from a support 18 of the lathe. This knife extends the length of the log and has a cutting edge 20 positioned to engage or cut into the log along the edges thereof. A pressure bar 22 is adjustably positioned near but spaced from the cutting edge of the blade, said bar being carried by a support 24 pivotally mounted at 26 on a frame 28, said support being moved towards and away from the knife 16 by means of a hydraulic or pneumatic cylinder 30. The thickness of the veneer cut from the log may be varied by adjusting the space 32 between the cutting edge 20 and the pressure bar 22. The frame 28 carrying the knife support 18 and the pressure bar support 24 is mounted on slides 34 which are advanced towards the log during rotation of the latter by means of lead screws 36 at predetermined speeds, the thickness of the veneer being determined by the rate of infeed of slides 34. In this manner, therefore, the knife and pressure bar are advanced in a plane transversely of the log whilst the latter is rotated. The veneer as it is cut from the log is directed downwardly onto a suitable conveyor 38.

The veneer lathe thus far described is of conventional construction. The log 14 is rotated around its longitudinal axis and veneer is cut therefrom by the knife 16 advancing towards the log axis. The cutting action of the knife and the transverse movement of both the knife and the pressure bar combine to exert a resultant force on the log in an upward and outward direction. This resultant force causes the log to bow outwardly and upwardly when it is cut down to a relatively small diameter, since at such time, the remaining wood is not strong enough completely to resist this force.

The log core steadying apparatus as shown in FIG- URES 1 to 4 includes a carrier 40 having a generally U-shaped arm 42 pivotally attached at 44 to a shaft 46 carried by stationary support post 48 mounted on the lathe sup-porting structure 50. The movement of the carrier 40 in the vertical plane is effected by means of a hydraulic cylinder 52 which is pivotally connected at 54 to the support 48. The cylinder has a piston rod 56 projecting therefrom, the free end 58 of this rod having a U-shaped bracket 60 formed thereon. The bracket 60 is attached to a plate 62 which is itself fixedly secured at either end to chains 64 and 66. Chains 64 and 66 pass around

sprockets

68 and 70 rotatably mounted on sup port 48 by means of lugs 72 and sprockets 74 and 76 fixedly attached to a hollow pin 78. The boom may be caused to rotate about the pivot 44 by movement of the' piston rod 56. Spaced-apart

steady rolls

80 and 82 are mounted in the carrier intermediate the ends thereof. Ilhese

steady rolls

80 and 82 are rotatably mounted in fork shaped brackets 84 which are fixedly attached to slides 86. A lead screw 88 having a bevel gear 90 attached to one end thereof is in screw engagement with slide 86 whereby rotation of the bevel 90 is effective to move the slide parallel to the axis of the lead screw. A pinion 92 mounted on shaft 94 for rotation therewith meshes with bevel gear 90. A sprocket 96 is fixedly mounted on shaft 94 and is connected with the sprocket 98 fixedly mounted on a shaft 100 by means of a chain 102. Shaft 100 has another sprocket 104 fixedly mounted thereon and this sprocket is connected by a chain 106 to a sprocket 108 fixedly mounted on shaft 110 which is rotatably mounted within pin 78. Two

other sprockets

112 and 114 are fixedly mounted on the shaft 110.

Sprocket 112 is connected by means of chain 113 to a' further sprocket 116 fixedly mounted on the shaft 118 of a hydraulic motor 120 for rotation thereby while sprocket 114 is connected to sprocket 122 by means of a chain 124. Sprocket 122 is fixedly connected to the driven member 126 of a clutch 127, the driving member 128 of said clutch being mounted on shaft 130 which is drivably connected to the main drive shaft of the latheby means of sprockets 132 and134 and chain 136. The operation of the clutch is controlled by means of a hydraulic cylinder 138 having an operating rod 140'projecting therefrom. Rod 140 is connected to one end of a link 142 pivotally mounted at 144 to the lathe supporting structure 59. The other end of rod 141? is connected to the driving member 128 of the clutch. With this arrangement, the steady roll feed means, i.e., the lead screws 88 may be driven either from the hydraulic motor 126 through

roller chains

113, 106 and 102 or, with the clutch engaged and the hydraulic motor oif, directly from the main drive shaft.

Operation of the steady rolls 8% andSZ is controlled by means of the electro-hydraulic system diagrammatically illustrated in FIGURES 5 and 6. A pump 150 driven through suitable gearing 152 by a motor 154 is adapted to direct fluid from reservoir 156 under pressure through a conduit network 158 provided with a number of solenoid-operated valves designated by the references S.V. With the carrier in its rest position and pump 150 energized, the operating fluid travels from the reservoir 156 through a solenoid-operated valve S.V.l.

When it is desired to lower the support roll carriage, switch P1 is closed thereby to energize the operating solenoid S1 of valve SV1. Energization of S1 causes valve SV1 to direct fluid from the pump to the upper end of the carrier control cylinder 52. The fluid entering cylinder 52 drives the piston 53 downwardly thereby lowering the carrier towards the lathe. When the log being worked has been reduced to a predetermined diameter the carrier strikes a mechanical stop positioned on the lathe carriage and simultaneously actuates first switch means consisting of a limit switch LS1. LS1 completes'a circuit through another limit switch LS2 for the operating solenoid S3 of a valve 8V2 whichlatter valve controls the operation of the hydraulic motor 126. Limit switch LS1 also breaks the circuit to the operating solenoid S4 of valve' SV3 thereby causing valve SV3 to pressurize the hydraulic system. The hydraulic motor 120 now begins to drive the support rolls towards the log. When the top support roll 82 engages the log it is rotated by the log and actuates second switch means comprisinga plugging switch P2 which is driven from the roll by means of chain 83. The plugging switch P2 closes a circuit overlimit switch LS3'for energizing relay R1. Relay R1 at contact r1 completes a circuit to energize the operating solenoid S5 of clutch 127. Upon engagement of the clutch 127 the support rolls are drivably connected to the lathe main drive shaft and are thus driven in synchronism with the lathe carriage and exert a pressure on the log opposed to the pressure exerted thereon by the knife and pressure bar. Engagement of clutch 127 is also effective to operate limit switch LS2, which breaks the circuit to the operating solenoid S3 of valve SVZ. Valve SVZ is thus opened and as a result the hydraulic motor 129 is stopped.

When the lathe carriage has travelled'as far forward as desired and the log is at its predetermined minimum diameter the carriage operates third switch means com prising a limit switch LS4 which closes, thereby completing a circuit for solenoid S6 which closes a holding circuit for itself over contact 86b. S6 is effective to reverse the direction of rotation of the lathe cross-feed drive shaft which then commences to return the lathe carriage to its normal rest position. The reversal of the direction of rotation of the drive shaft is also elfective to return the steady rolls to their uppermost position. When the steady rolls reach their uppermost position they engage further switch means consisting of limit switch LS3, operation of which breaks the circuit to relay R1 and completes a circuit for solenoid S7 thereby disengag ingclutch 127 and stopping any further movement of the support rolls. Limit switch LS4 also completes through contact Sea a circuit for relay R2 which closes a holding circuit for itself over contact 12a and at contacts r212 completes a circuit to solenoid S2. Energization of S2 is effective to cause valve SV1 to direct fluid from the pump to the lower end of cylinder 52 thereby driving piston 53 upwardly to return the support carrier to its uppermost position. When the support roll carrier reaches its uppermost position, it operates a limit switch LS6 which opens a circuit to deenergize relay R2, which at contacts r2b de-energizes solenoid S2, thereby to return valve SV1 to its restposition. In addition to the limit switch, a button operated switch P3 is also provided on the machine so that the solenoid S2 may be energized and the support roll carrier may be raised whenever desired merely by closing switch P3 thereby energizing re: lay R1 which at contact r21; completes a circuit to operate solenoid S2. The provision of this manually operated push button switch P3. enables the lathe operator to return the support roll carrier to its rest position at any time, if necessary, without disturbing the functions of the lathe.

It will be appreciated that the foregoing describes only one embodiment of the invention and that many variations in detail can be envisaged. The illustrated embodiment is the preferred form; of the invention, but this does not preclude the introduction of other variations into the log steadying apparatus.

What I claim as my invention is:

1. In a rotary veneer lathe comprising means for supporting a log for rotation about its longitudinal axis, lathe drive means for rotating said log, a knife and pressure bar associated therewith, and means for moving said knife and pressure bar in a direction transversely of the axis of rotation of the log, apparatus for continuously steadying said log, said apparatus comprising a carrier pivotally mounted on said lathe and having at least two spaced support rolls mounted therein, said carrier positioned at the opposite side of said axis from said knife bar; carrier drive means for moving said carrier towards and away from said axis; feed means for moving said support rolls relative to said carrier in a direction towards and away from said axis; first switch means operable when said carrier has been moved a predetermined distance towards said axis to activate said feed means thereby to move said support rolls towards the log; second switch means operable upon engagement of said support rolls with said log for coupling the feed means to said lathe drive means thereby to drive said rolls in synchronism with the lathe drive means to exert a pressure on said log substantially equal andopposite to that exerted thereon by said knife; third switch means operable upon reduction of the log to a predetermined diameter to reverse the direction of rotation of said lathe drive means thereby to withdraw said knife bar and said support rolls from engagement with the log; and further switch means operable upon a predetermined withdrawal of the support rolls to their normal position to disengage said feed means from said lathe drive means thereby to stop any further movement of the support rolls and to energize said carrier drive means to return said carrier to its normal position away from said axis.

2. In a rotary veneer lathe comprising means for supporting a log for rotation about its longitudinal axis, lathe drive means for rotating said log, a knife and pressure bar associated therewith, and means for moving said knife and pressure barin a direction transversely of the axis of rotation of the log, apparatus for continuously steadying said log, said apparatus comprising a carrier pivotally mounted on said lathe and having at least two spaced support rolls mounted therein, said carrier positioned at the opposite side of said axis from said knife bar, carrier drive means for moving said carrier towards and away from said axis; feed means for moving said support rolls relative to said carrier in a direction towards and away from said axis; a normally disengaged clutch coupling said support roll feed means to said lathe drive means; first switch means operable when said carrier has been moved a predetermined distance towards said axis to activate said feed means thereby to move said support rolls towards the log; second switch means operable upon engagement of at least one of said support rolls with said log to engage said clutch, engagement of said clutch effective to couple said support rolls into drivable engagement with the lathe drive means, thereby to urge said support rolls against the log to exert a pressure thereon substantially equal and opposite to that exerted on the log by said knife; third switch means operable upon reduction of the log to a predetermined diameter to reverse the direction of rotation of said lathe drive means, thereby to withdraw said knife bar and said support rolls from engagement with the log; and further switch means operable upon return of said support rolls to their normal position to disengage said clutch thereby to stop any further movement of said support rolls and to energize said carrier drive means to return said carrier to its normal position away from said axis.

3. In a rotary veneer lathe comprising means for supporting a log for rotation about its longitudinal axis, lathe drive means for rotating said log, a knife and pressure bar associated therewith, and means for moving said knife and pressure bar in a direction transversely of the axis of rotation of the log, apparatus for continuously steadying said log, said apparatus comprising a carrier pivotally mounted on said lathe and having at least two spaced support rolls mounted therein, said carrier positioned at the opposite side of said axis from said knife bar, carrier drive means for moving said carrier towards and away from said axis; feed means for moving said support rolls relative to said carrier in a direction towards and away from said axis; a motor mounted on said carrier and coupled to said support roll feed means; a normally disengaged clutch coupling said support rolls to said lathe drive means; first switch means operable when said carrier has been moved a predetermined distance towards said axis to energize said motor, thereby to move said support rolls towards the log; second switch means operable upon engagement of said support rolls with said log to engage said clutch, engagement of said clutch eifective to de-energize said motor and to couple said support rolls in drivable engagement with the lathe drive means thereby to urge said support rolls against the log to exert a pressure thereon substantially equal and opposite to that exerted on the log by said knife; third switch means operable upon reduction of the log to a predetermined diameter to reverse the direction of rotation of said lathe drive means thereby to withdraw said knife bar and said support rolls from engagement with the log; and further switch means operable upon return of said steady rolls to their normal position to disengage said clutch thereby to stop any further movement of said support rolls and to energize said carrier drive means to return said carrier to its normal position away from said axis.

4. In a rotary veneer lathe comprising means for supporting a log for rotation about its longitudinal axis, lathe drive means for rotating said log, a knife and pressure bar associated therewith, and means for moving said knife and pressure bar in a direction transversely of the axis of rotation of the log, apparatus for continuously steadying said log, said apparatus comprising a carrier pivotally mounted on said lathe and having at least two spaced support rolls mounted therein, said carrier normally positioned away from said axis at the opposite side thereof from said knife bar intermediate the ends of said log; fluid pressure actuated means connected to the carrier for moving it towards and away from said axis; feed means for moving said support rolls relative to said carrier in a direction towards and away from said axis; a fluid pressure actuated motor mounted on said carrier and coupled to said support roll feed means; first switch means operable when said carrier has been moved a predetermined distance towards said axis to energize said motor, thereby to move said support rolls towards the log; second switch means operable upon engagement of said support rolls with said log to de-energize said motor and to couple the feed means to said lathe drive means thereby to drive said rolls in synchronism with the lathe drive means to exert a pressure on said log substantially equal and opposite to that exerted thereon by said knife; third switch means operable upon reduction of the log to a predetermined diameter to reverse the direction of rotation of said lathe drive means thereby towithdraw said knife bar and said support rolls from engagement with the log; and further switch means operable upon a predetermined withdrawal of the support rolls to their normal position to disengage said feed means from said lathe drive means, thereby to stop any further movement of the support rolls and to energize said carrier moving means to return said carrier to its normal position away from said axis.

5. In a rotary veneer lathe comprising means for supporting a log for rotation about its longitudinal axis, lathe drive means for rotating said log, a knife and pressure bar associated therewith, and means for moving said knife and pressure bar in a direction transversely of the axis of rotation of the log, apparatus for continuously steadying said log, said apparatus comprising a carrier pivotally mounted on said lathe and having at least two spaced support rolls mounted therein, said carrier positioned at the opposite side of said axis from said knife bar; means connected to said carrier for moving said carrier towards and away from said axis, said moving means comprising a fluid cylinder having a piston rod mounted for reciprocation therein, said piston rod extending between and connected to the carrier and the lathe; feed means for moving said support rolls relative to said carrier in a direction towards and away from said axis; a motor mounted on said carrier and coupled to said support roll feed means; first switch means operable by said carrier when the latter is moved a predetermined distance towards said axis to energize said motor, thereby to move said support rolls towards the log; second switch means operable upon engagement of said support rolls with said log to de-energize said motor and to couple the feed means to said lathe drive means thereby to drive said rolls in synchronism with the lathe drive means and to exert a pressure on said log substantially equal and opposite to that exerted thereon by said knife; third switch means operable upon reduction of the log to a predetermined diameter to reverse the direction of rotation of said lathe drive means thereby to withdraw said knife bar and said support rolls from engagement with the log; and further switch means operable upon a predetermined withdrawal of the support rolls to their normal position to disengage said feed means from said lathe drive means, thereby to stop any further movement of the support rolls and to energize said carrier drive means to return said carrier to its normal position away from said axis.

6. In a rotary veneer lathe comprising means for supporting a log for rotation about its longitudinal axis, lathe drive means for rotating said log, a knife and pressure bar associated therewith, and means for moving said knife and pressure bar in a direction transversely of the axis of rotation of the log, apparatus for continuously steadying said log, said apparatus comprisng a carrier pivotally mounted on said lathe and having at least two spaced support rolls mounted therein, said carrier positioned at the opposite side of said axis from said knife bar, carrier drive means for moving said carrier towards and away from said axis; feed means for moving said support rolls relative to said carrier in a direction towards and away from said axis; a motor mounted on said carrier and coupled to said support roll feed means; a normally disengaged clutch coupling said support rolls to said lathe drive means; first switch means operable by said carrier when the latter is moved a predetermined distance towards said axis to energize said motor, thereby to move said support rolls towards the log; second switch means operable upon engagement of said support rolls with said log to engage said clutch, engagement of said clutch eifective to deenergize said motor and to couple said support rolls in drivable engagement with the lathe drive means thereby to urge said support rolls against the log to exert a pressure thereon substantially equal and opposite to that exerted on the log by said knife; third switch means operable upon reduction of the log to a predetermined diameter to reverse the direction of rotation of said lathe drive means thereby to withdraw said knife bar said said support rolls from engagement with the log; and further switch means operable upon return of said support rolls to their normal position to disengage said clutch, thereby to stop any further movement of said support rolls and to energize said carrier drive means to return said carrier to its normal position awayfrom said axis.

7. In a rotary veneer lathe comprising means for supporting a log .for rotation about its longitudinal axis, lathe drive means for rotating said log, a knife and pressure bar associated therewith, and means for moving said knife and pressure bar in a direction transversely of the axis of rotation of the log, apparatus for continuously steadying said log, said apparatus comprising a carrier pivotally mounted on said lathe, said carrier positioned at the opposite side of said axis from said knife bar; a pair of spaced support rolls mounted on said carrier and extending longitudinally of the log intermediate the ends thereof; fluid actuated means connected to the carrier for moving said carrier towards and away from said axis; feed means for movingsaid support rolls relative to said carrier in a direction towards and away from saidaxis; a hydraulic motor mounted on said carrier and coupled to said support roll feed means; a normally disengaged clutch coupling said support rolls to said lathe drive means; first switch means operable by said carrier when the latter has moved a predetermined distance towards said axis to energize said hydraulic motor thereby to move said support rolls towards the log; second switch means operable upon engagement of said support rolls with said log to engage said clutch, engagement of said, clutch effective to dc-energize said hydraulic motor and to couple said feed means to said lathe drive means thereby to drive said rolls in synchronism with the lathe drive means and exert a pressure on said log substantially equal and opposite to that exerted thereon by said knife; third switch. means operable upon reduction of the log to a predetermined diameter to reverse the direction of rotation of said lathe drive means thereby to withdraw said knife bar and said support rolls from engagement with the log; and further switch means operable upon a predetermined withdrawal of the support rolls to disengage said clutch and decouple the feed means from said. .lathedrive means thereby to stop any further movement of the support-rolls and to energize said fluid actuated carriermoving meansto return said carrier to its normal position awayfrom said axis.

8. In a rotary'veneer lathe comprising means for supporting a log for rotation about its longitudinal axis, lathe drive means for rotating said log, a knife and pressure barassociated therewith, and means for moving said knife and pressure bar in a direction transversely of the axis of rotation of the log, apparatus for continuously steadying'said log, said apparatus comprising a carrier pivotally mounted on said lathe and having at least two spaced support rolls mounted'therein, said carrier positioned at the opposite side of said axis from said knife bar, carrier drive means for moving said carrier towards and away from said axis; feed means for mov ing said support rolls relative to said carrier in a direction towards and away from said axis; a hydraulic motor mounted on said carrier and coupled to said support roll feed means; a normally disengaged clutch coupling said support rolls to said lathe drive means; first switch means operable by said carrier when the latter has moved a predetermined distance towards said axis.

to energize said motor thereby to move said support rolls towards the log; second switch means operable upon engagement of said support rolls with said log to engage said clutch, engagement of said clutch eflective to deenergize said motor and to couple said support rolls into drivable engagement with the lathe drive means, thereby to urge said support rolls against the log to exert a pressure thereon substantially equal and opposite to that exerted on the log by said knife; third switch means operable upon reduction of the log to a predetermined diameter to reverse the direction of rotation of said lathe drive means thereby to withdraw said knife bar and said support rolls from engagement with the log; and further switch means operable upon return of said steady rollsto their normal position to disengage said clutch thereby to stop any further movement of said support rolls and to energize said carrier drive means to return said carrierto its normal position away from said axis.

9. Apparatus for steadying a log in a rotaryv veneerlathe in which a knife and apressure bar are advanced in a plane transversely of the log as the latter is rotated about its axis, said apparatus comprising a carrier pivotally mounted on said lathe and normally positioned away from said axis at the opposite side thereof from said knife bar; a pair of spaced support rolls mounted on said carrier and extending longitudinally of the log intermediate the ends thereof; fluid actuated means connected to the carrier for moving said carrier towards and away from said axis; 7

feed means for moving said support rolls relative to said carrier in a direction towards and away from said axis; a

switch means operable upon engagement of said support rolls with said log to engage said clutch, engagement of I said clutch effective to de-energize said motor and to couple said support rolls in drivable engagement with the lathe drive means thereby to urge said support rollsagainstthe log to'exert a pressure thereon substantially equal and opposite to that exerted on the log by said knife; third switch means operable upon reduction of the log to a predetermined diameter to reverse the direction of rotation of said lathe drive means therebyto withdraw said knife bar and said support rolls from engagement with the log; and further switch means operable upon return of said steady rolls to their normal position to dis: engage said clutch thereby to stop any further movement of said support rolls and to energize said carrier drive means to return said carrier to its normal position away from said axis.

References Citedin the file of this patent UNITED STATES PATENTS 412,553 Smith Oct. 8, 1889 2,766,786 Molyneux Oct. 16, 1956 2,884,966 Zilm May 5, 1959