US3078887A - Lathe with log-supporting mechanism - Google Patents

Description

Feb. 26, 1963 E. M. HETH 3,073,337

' LATHE WITH'LOG-SUPPORTING MECHANISM Filed March 7, 1961 2 Sheets-Sheet 1 Edwin M.H 'l'h INVENTOR.

Feb. 26, 1963 Filed March 7, 1961 E. M. HETH LATHE WITH LOG-SUPPORTING MECHANISM 2 Sheets-Sheet 2 m Edwin M.Hefh 3 [A INVENTOR. Q

g A!" 4 g fi wa g I AH- rs.

United States Patent Office 3,fi78,887 Patented Feb. 26, 1963 $378,887 LATER WITH LUG- UPPURTING MECHANESM Edwin M. l-leth, Portland, Greg, assignor to Premier Gear & Machine Works, lno, Portland, reg., a corporation of Oregon Fiied Mar. 7, 1961, Ser. No. 93,922 12 Claims. (Ci. 144-209) This invention relates to veneer lathes, and more particularly to a lathe that includes means for supporting intermediate portions of a log during the cutting of veneer therefrom, whereby better cut veneer results and the log can be reduced to the smallest possible core.

The usual veneer lathe has a pair of pedestals mounting spaced-apart and opposed chucks that hold the ends of the log during the cutting of veneer therefrom. Typically a carriage is provided the lathe, and mounting a knife and pressure bar, is advanced toward the log, with the knife cutting veneer and with the pressure bar exerting a pressure on and steadying the log during cutting. The knife and bar exert forces on the log intermediate where its ends are held by the lathe chucks, and consequently there is a tendency for the middle part of the log to be pushed outwardly from alignment with the chuck centers, particularly evident when the log is peeled down to a relatively small core. To correct these tendencies, it has been suggested that some kind of support or steady rest be provided the log, operable to counteract these dislocating forces that otherwise cause the log to bow outwardly.

Generally, it is an object of this invention to provide improved means for steadying or supporting portions of a log extending between the chucks of a lathe during the cutting of veneer therefrom.

In the typical lathe, the knife and pressure bar are disposed at a height that approximately corresponds to the elevation of the center axes of the chucks. The knife and bar are advanced inwardly on a log, from a position they have to one side of the chucks, and the log is rotated so that its surface is moving down on the knife during cutting. As a result, forces are exerted on the log that have a direction extending upwardly and toward the side of the chucks opposite the side where the knife is disposed. Steadying means for a log preferably should be such that a substantially uniform amount of support be provided the log, regardless of variations in diameter. To enable most simply that such support be provided a log, and included in the objects of this invention, this invention contemplates the provision of support mechanism that moves inwardly on a log, as veneer is removed and the logs diameter becomes smaller, along substantially a straight path, such path approximately coinciding with the direction of the forces exerted on the log by the action of the knife. Regardless of log diameter, the support mechanism exerts a total force on the log that extends in a direction approximately opposite to the direction of the total force exerted on the log by the action of the knife and pressure bar.

Another factor to be considered in the construction of a lathe, is the ease with which a core may be removed from the lathe after all veneer has been cut therefrom, and a new log substituted for the core removed. Maximum production is possible if this substitution of a new log is made as speedily as possible. To facilitate removal of a core, it is sometimes advantageous, after loosening of the chucks, to extend the means used for steadying the core, so that it performs the additional function of pushing the core out from between the chucks. After this, the steadying means should be retracted swiftly, to clear quickly the space between the chucks for a new log. Accordingly, it is another object of this invention to provide an improved construction for support or steadying means or mechanism of the type contemplated, that may be actuated so as to assist in the removal of a final core, and then cleared rapidly from between the chucks of a lathe to free the lathe for the reception of a new log.

In a more specific sense, it is an object of this invention to provide a lathe which includes, as support mechanism for a log, an elongated extensible-retractable arm, mounted for pivotal movement about an axis paralleling and above the axes of the chucks of the lathe, such axis being on the side of the lathe opposite the side on which the knife and roller bar are disposed. The arm is swingable from a raised position where its free or nonpivoted end is above the lathe, to a lowered position where the free end thereof is adjacent the periphery of a log. The extensible-retractable arm has means provided its nonpivoted end for contacting a log and exerting a pressure thereon, such pressure being exerted during lathe operation in a direction coinciding with the direction in which the arm is extensible.

Another object is to provide a lathe with such an arm for providing support, wherein power-operated means is provided for swinging the arm between raised and lowered positions, and the arm has a pivot axis so located that the free end of the arm, in moving toward a raised position, moves in a direction toward and then over the knife, so that the space between the lathe chucks is immediately cleared for the supply of a new log to a lathe.

Another object is to provide a lathe with steadying mechanism for a log, where such mechanism comprises an elongated arm, and a pair of power-operated means for placing the end of the arm in an inoperative, out of the way position, one of these power-operated means being effective to swing the arm in an arc upwardly and the other being effective to withdraw the end backwardly along the length of the arm.

Still a further object is to provide a novel construction for an extensible-retractable arm, used as steadying mech anism in a lathe, where the arm is well suited to withstand the stresses and strains it normally is subjected to during the peeling of veneer from a log.

These and other objects and advantages will become more apparent, as the following description is read in conjunction with the accompanying drawings, wherein:

FIG. 1 is a view of the back of a lathe, such lathe being provided with log steadying mechanism constructed according to one embodiment of this invention;

FIG. 2 is a view of one side of the lathe shown in FIG. 1, with portions removed therefrom;

FIG. 3 is a view, somewhat enlarged and with portions removed, of an elongated extensible-retractable arm present in the construction; and

PEG. 4 is an enlarged, cross-sectional view, taken along the line 44 in FIG. 3.

Referring now to the drawings, at 10 there is indicated generally a lathe, such lathe having a base frame 12 and mounted on frame 12 and spaced from each other a pair of opposed pedestals 14, 16. Projecting inwardly from pedestals 14, 16 are opposed and spaced-apart chucks 18, 20, such chucks typically having center axes that are aligned and horizontally disposed. The location of these axes is indicated in FIG. 2 at 17. The usual mechanism (not described as it forms no part of the invention) is provided for moving the chucks toward and away from each other, to hold and to release a log, respectively. Power-operated means (not shown) is provided for rotating the chucks, whereby a log held by the chucks is rotated about an axis coinciding with the aligned center axes of the chucks, such axis therefor also being designated at 17 in FIG. 2 (during operation of the lathe, the log is rotated in a clockwise direction in FIG. 2).

Lathe 10 includes a carriage shown in outline at 28',

that is movable to and fro between the pedestals by means of feed screws such as feed screw 30, thus to position a log supported on chucks 18, 20 relative to the carriage. Mounted on the carriage, and indicated at 32, 34, respectively, are the usual knife and pressure bar. The knife and pressure bar substantially parallel a log on the lathe and are positioned approximately at the height of the center axes of the chucks. As the outside of a log revolves against the knife and bar, a sheet of veneer is produced, with the log progressively getting smaller in diameter as veneer is removed.

As so far described, the lathe is conventional, and thus it has not been described in too great detail. In general terms, it may be said that the lathe is typified by a knife and pressure bar disposed to one side and at approximately the height of the center axes of the chucks, that are advanced into the outside of a log, with the logs surface moving downwardly on the knife and bar, to produce a sheet of veneer.

During the cutting of veneer, because of the pressure exerted by the knife and bar on the log and because of the downward movement of the log surface on the knife, a force is exerted on the log which extends generally upwardly and to the left, viewing the lathe as in FIG. 2. Such force tends to produce bowing in the log, particularly when it has been reduced to a core of relatively small diameter. To inhibit such bowing tendencies, a support or steady rest mechanism for the log is provided, indicated generally at 40, which is used to brace the log between its ends.

Specifically, 42 indicates an elevated frame, supported above the floor by legs 44. The frame is above the chucks, and extends to the left of chucks, viewing the lathe as in FIG. 2. The elevated position of the frame enables new logs to be supplied the lathe, moving the logs in from the left in FIG. 2, without encumbrance by the frame.

Frame 42 includes an elongated beam 46 that substantially parallels a log in the lathe, and extends between the lathe pedestals. Disposed above chucks 18, 20 and substantially midway between them, and pivotally connected to beam 46, by pivot means 48, is an elongated extensibleretractable mechanism or arm 52. Pivot means 48 is above and to the left of the chucks in FIG. 2, which enables mechanism 52 to be swung from the inoperative position shown in solid outline in FIG. 2, downwardly with its nonpivoted or free end moving in an are as indicated by the arrows in FIG. 2. In its lowered position, shown in dashed outline in FIG. 2, the free end of arm 52, pivot means 48, and axis 17 are in substantial alignment. The arm in its lowered position extends upwardly from a log in a direction substantially coinciding with the direction of the forces exerted on a log by knife 32 and the bar during cutting by the knife.

Arm 52 comprises a pair of rigid, telescopic sections 58, 60, each of which has a substantially rectangular cross section, as can be seen with reference to FIG. 4. Inner section 60 is slidably received within outer section 58. The sections are extensible and retractable with respect to each other, and are shown in their relatively contracted position in FIG. 3.

Various forms of constructions may be used for sections 58, 60. In the embodiment illustrated, the outer section has topand bottom walls 61, 62 and opposed side walls 63, 64 forming an enclosed box-like structure, closed at its left end in FIGS. 2 and 3 by end wall 65. Inner section 60 comprises opposed, approximately channelshaped members 67, 68, held together by end plates 70, 71 and intermediate plate 72 (see FIG. 3).

Secured to the outside of and extending forwardly from inner section 60, and part of the section, are plates 80 (the plate 80 on the rear side of section 60 is obscured in FIGS. 2 and 3). Pivotally mounted on these plates, by pivot connections 86, are mounting plates 84. The mounting plates 84 extend forwardly of the pivot connections 86, and have rollers 82, 83 journaled thereon. Pivotal movement of the plates is limited by stops 88 projecting inwardly from plates 80. The rollers in an operative position for arm 52, as can be seen with reference to the dashed outline of the arm in FIG. 2, rotate about axes that parallel a log being cut, and constitute the means in the mechanism actually contacting a log when the same is being steadied.

Extension of the sections, and retraction, is produced by a fluid-operated jack or ram, indicated at 100, disposed within sections 58, 60, so that the ram is protected by the sections. The cylinder end of ram is pivotally connected to end wall 65 of outer section 58, whereas the rod end is pivotally connected to plate 72 of inner section 60. End plate 70 of section 60 has an aperture 102 formed therein which accommodates the connection of ram 100 with end wall 65.

Means is provided for swinging the arm between the raised position shown in solid outline in FIG. 2 and the lowered position indicated in dashed outline. Thus, a ram or jack 110, is included, that has its rod end connected by pivot connection 112 to outer section 58, and its cylinder end connected by pivot connection 114 to a beam 116 which is part of elevated frame 42.

Explaining now the operation of the apparatus described, with the arm raised and in its inoperative position, it is out of the way of the space between the chucks, which enables a log to be supplied the lathe and properly positioned on the chucks. During cutting of veneer, and before the log is reduced to a core of small diameter, ram and ram 100 may be actuated, causing the arm to swing to its lower position and to extend, to place rollers 82, 83 in rolling contact with the periphery of the log. In such position, the rollers function to support the log, by exerting a force on the log that counteracts forces exerted on the log by the knife and roller bar. When cutting of veneer is finished, the lathe chucks may be retracted, and ram 100 may be extended to its full extent, to assist in freeing the core remaining from the chucks. Arm 52 may then be quickly moved out of the way, by simultaneous retraction of rams 100, 110, with the free end of the arm retracting and also swinging upwardly.

It will be noted that the construction has several advantages. The arm is extensible along a straight path that approximately coincides with the direction of the forces exerted on the log by the knife and pressure bar. This facilitates the application of a steady, even pressure on the log. It should be noted also that since the arm is swung toward the knife and upwardly in moving to a retracted position, there is almost immediate clearance of the space between the chucks of the lathe after the removal of the core. This is so, even if the mechanism is relied upon to assist in clearing the lathe. Note also that both retraction of the arm and swinging of the arm can be utilized in clearing the space between the lathe chucks.

The telescopic sections have the requisite rigidity to withstand shocks and stresses imparted thereto. They are easily shifted to a fully extended position. The ram producing extension and retraction of the sections is fully protected from stresses by the telescopic sections that encompass it.

I claim:

1. In a veneer lathe having opposed spaced-apart chuck-s for holding the ends of a log and rotating it about a rotation axis extending between the chucks, and a knife extending between and positioned laterally to one side of the chucks for cutting a sheet of veneer from the log, support means for the log comprising elongated power-operated lineally extensible mechanism positioned intermediate the ends of the knife and laterally to the other side of said chucks from said kuife, means disposed on said other side of said chucks and above the chucks pivotally mounting one end of said mechanism and accommodating pivotal movement of the mechanism about an axis substantially paralleling said rotation axis, the end of said mechanism opposite said one end being swingable in an are from a raised position disposed above ,the

chucks downwardly to a position where said opposite end is adjacent said rotation axis, means provided said opposite end of the mechanism for contacting the, log

.and operable to exert. a pressure against the log, and

power-operated means connected to said extensible mechanism for swinging it in said arc.

2. In a veneer lathe having opposed spaced-apart chucks for holding the ends of a log and rotating it about :a rotation axis extending between'the chucks, and a tensible armincluding means for extending said arm, pivot means disposed above the chucks pivotally mounting one end of said arm with the arm depending from the pivotmeans and in a position'where the end opposite said one. end may swing'in an'arc toward and then above said knife on pivotal movement of the arm, means on said .opposite end of said arm for contacting a log and operable to exert a pressure on the, log, and power-operatedmeans'connected to said arm for swinging it in said arc.

3. In a veneer lathe having opposed spaced-apart chucks for holding the ends of a log and rotating it about a rotation axis extending between the. chucks, and a knife extending between and positioned laterally to one side of the chucks for cutting a sheet of veneer from a log, means for supporting the log at a location intermediate its ends, said means comprising an elongated arm having a pair of rigid sections, one forming one end and one forming the other end of said arm, said sections being mounted with one section slidable relative to the other whereby the arm is extensible and retractable, a fluid-operated ram mounted on said arm with one end secured to one of said sections and its opposite end secured to the other of said sections and operable on actuation to produce extension and retraction of the arm, pivot means disposed above the chucks pivotally mounting the section forming one end of the arm with said arm depending from said pivot means and in a position where the end of the arm opposite said one end may swing in an arc toward and then above said knife on pivotal movement of the arm, means on said opposite end of said arm for contacting a log and operable to exert a pressure on the log, and power-operated means connected to said arm for swinging it in said arc.

4. In a veneer lathe having opposed spaced-apart chucks for holding the ends of a log and rotating it about a rotation axis extending between the chucks, and a knife extending between and positioned laterally to one side of the chucks for cutting a sheet of veneer from the log, means for supporting the log at a location intermediate its ends, said means comprising an elevated frame disposed above and to the other side of said chucks from said knife, an elongated arm having a pair of rigid sections, one forming one end and one forming the other end of said arm, said sections being mounted with one slidable relative to the other whereby the arm is extensible and retractable, a fluid-operated ram mounted on said arm with one end secured to one of said sections and its opposite end secured to the other of said section and operable on actuation to produce extension and retraction of the arm, pivot means disposed above the chucks pivotally mounting the section forming one end of the arm with said arm depending from said pivot means and in a position where the end opposite said one end may swing in an arc toward and then above said knife on pivotal movement of the arm, means on said opposite end of said arm for contacting a log and operable to exert a pressure on the log, and poweroperated means connected to said arm for swinging it in said arc, said power-operated means comprising a fluid- 6 operated ram pivotally connected at'oneend to said arm and pivotally connected at its other end to said support. 5. In a veneer lathe having opposed spaced-apart chucks for holding the ends of a log and rotating it about arotation axis-extending between the chucks, and a'knife extending between and positioned laterally to one side of the chucks for cutting a sheet of veneer from the log, support means for the log comprising elongated power-operated extensible-retractable mechanism positioned intermediate the ends of the knife and laterally to the other side of said chucks from said knife, said mechanism comprising a pair ofrigid sectionswith one mounted on the other and slidable relative to the other to produce extension and retraction of the mechanism, and a-fluidoperated ram mounted'with one end connected to one of said sections and the other end connected to the other of said sections operable on' actuation to produce extendownwardly to a-position-where said opposite end is adjacent said rotation axis, means provided said opposite end of said mechanism for contacting the log and operable to exert a pressure against'theflog, and power-operated means connected to said'mechanism for swinging it in said are.

6.*The lathe 0f'claim5 wherein an elevated frame'is provided above said chucks and wherein the power-operated means for swinging the mechanism in said are comprises a fluid-operated ram pivotally connected at one of its ends to one of said sections at the other of its ends to said elevated frame.

7. In a veneer lathe having opposed spaced-apart chucks for gripping the ends of a log and for rotating it about an axis extending between the chucks, and a knife extending between and positioned laterally to one side of the chucks for cutting a sheet of veneer from the log, an elevated frame supported above said chucks and to the other side of said chucks from said knife, an elongated lineally extensible arm, means pivoting one end of said arm on said elevated frame at a location disposed above said chucks and on said other side of said chucks, said arm having an end opposite said one end that is swingable in an are between a raised position above said chucks and a lowered position where said opposite end and said one end are substantially aligned with the log rotation axis, power-operated means mounted on said arm for producing extension and retraction thereof, means on said other end of said arm for engaging a log and exerting a pressure thereon, and power-operated means interposed between said arm and said elevated frame for swinging said arm between its raised and lowered positions.

8. In a veneer lathe having opposed spaced-apart chucks for gripping the ends of a log and for rotating it about an axis extending between the chucks, and a knife extending between and positioned laterally to one side of the chucks for cutting a sheet of veneer from the log, an elevated frame supported above said chucks and to the other side of said chucks from said knife, an elongated extensible-retractable arm, said arm being formed of a pair of hollow telescopic sections, one received within the other, with the sections extensible and retractable relative to each other, means pivoting one end of said arm by pivotally mounting one of the sections on said elevated frame and at a location disposed above said chucks and on said other side of said chucks, said arm having an end opposite said one end that is provided by said other section and is swingable in an are between a raised position above said chuck and a lowered position where said opposite end and said one end are of the arm substantially aligned with the rotation axis of the log, a ram disposed within said telescopic sections and shielded thereby, means connecting one end of said ram to one of said sections and the other end of the ram to the other of said sections whereby actuation of the ram produces extension and retraction of the arm, means on said opposite end of said arm for engaging a log and exerting a pressure thereon, and power-operated means interposed between said arm and said elevated frame for swinging said arm between its raised and lowered positions.

9. The lathe of claim 8 wherein the means for swinging said arm comprises a fluid-operated ram with a cylinder end pivotally connected to said elevated frame and a rod end pivotally connected to one of said telescopic sections.

10. The lathe of claim 8 wherein the means for contacting a log comprises a pair of rolls spaced one from the other and substantially paralleling said rotation axis, and a mounting for the rolls pivotally mounted on said other section.

11. In a veneer lathe having opposed spaced-apart chucks for holding the ends of a log and rotating it about a rotation axis extending between the chucks, and a cutting assembly extending between the chucks and positioned laterally to one side of said axis, means for supporting a log in the lathe comprising an elongated arm, means pivotally mounting one end of said arm at a point spaced laterally toward the opposite side of said rotation axis from said one side, said arm having an end opposite said one end that is lineally extensible from said one end, power-operated means for producing extension of said opposite end of said arm from said one end, and means on said opposite end of said arm for contacting the log and operable to exert a force on the log, said opposite end of said arm with the arm in operative position and supporting a log being extensible in a direction substantially opposite to the direction of the total force exerted on the log by the cutting assembly of the lathe.

12. In a veneer lathe having opposed spaced-apart chucks for holding the ends of a log and rotating it about a rotation axis extending between the chucks, and a cutting assembly extending between the chucks and p0 sitioned laterally to one side of said axis, means for sup porting a log in the lathe comprising an elongated arm positioned laterally to the other side of said rotation axis from said cutting assembly, means mounting said arm with the arm projecting out from its mounting toward said rotation axis in a direction substantially opposite to the direction of the total force exerted on a log by the cutting assembly of the lathe, said arm terminating in an end adjacent said rotation axis that is extensible lineally in the same direction that the arm projects from its mounting, means on said end for contacting a log and exerting a force thereon, and power-operated means for producing extension of said arm.

References Cited in the file of this patent UNITED STATES PATENTS 2,884,966 Zilm May 5, 1959

Claims (1)

1. 2. IN A VENEER LATHE HAVING OPPOSED SPACED-APART CHUCKS FOR HOLDING THE ENDS OF A LOG AND ROTATING IT ABOUT A ROTATION AXIS EXTENDING BETWEEN THE CHUCKS, AND A KNIFE EXTENDING BETWEEN AND POSITIONED LATERALLY TO ONE SIDE OF THE CHUCKS FOR CUTTING A SHEET OF VENEER FROM THE LOG, MEANS FOR SUPPORTING THE LOG AT A LOCATION INTERMEDIATE ITS ENDS COMPRISING AN ELONGATED LINEALLY EXTENSIBLE ARM INCLUDING MEANS FOR EXTENDING SAID ARM, PIVOT MEANS DISPOSED ABOVE THE CHUCKS PIVOTALLY MOUNTING ONE END OF SAID ARM WITH THE ARM DEPENDING FROM THE PIVOT MEANS AND IN A POSITION WHERE THE END OPPOSITE SAID ONE END MAY SWING IN AN ARC TOWARD AND THEN ABOVE SAID KNIFE ON PIVOTAL MOVEMENT OF THE ARM, MEANS ON SAID OPPOSITE END OF SAID ARM FOR CONTACTING A LOG AND OPERABLE TO EXERT A PRESSURE ON THE LOG, AND POWER-OPERATED MEANS CONNECTED TO SAID ARM FOR SWINGING IT IN SAID ARC.

Images