US3379230A - Finishing machine - Google Patents

Description

Aprii 23, 1968 P J. ROEHRIG FINISHING MACHINE Filed Dec. 15, 1965 Q o o0 MVEZMFOM QM .m m6 on April 23, 1968 P. J. RCQEl-QRIG FINISHING MACHINE 4 Sheets-Sheet .2

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Apnl 23, 1968 P. J ROEHRIG FINISHING MACHINE 4 Sheets-Sheet 5 Filed Dec 13 1965 NYE; MToK-L) MIL- ed. oewz W yamd IQMBYJ April 23, 1968 P. J. ROEHRIG FINISHING MACHINE 4 Sheets-Sheet 4 Filed Dec. 13,

I IQVENTOM Dhdh Qjrgoehn I W 170v; CRTTOmByf' United States Patent 3,379,239 FINISHING MACHINE Phillip J. Roehrig, Rockford, Ili., assignor to Solem Machine Company, Rockford, llL, a corporation of Illinois Filed Dec. 13, 1965, Ser. No. 513,480 11 Claims. (Cl. 144-1) ABSTRACT OF THE DISCLOSURE A combined planing and sanding machine having planing and sanding heads disposed above a resiliently compressibl belt conveyor for successive engagement with a substantially fiat workpiece on the conveyor. The latter comprises a series of rigid slats joined together in an endless belt with rubber blocks fastened tothe slats to engage the work, the slats sliding along a rigid backing, and the planing head is a cylinder with helical rows of teeth fitted therein. The sanding head uses an endless belt guided around three rolls, one of which presses the belt against the planed surface of the work. To center the work on a predetermined longitudinal reference plane, pressure rolls yieldably press the work into the conveyor ahead of the planing head, a pressure plate engages the planed surface between the heads, and another pressure plate engages the sanded surface beyond the sanding head. An alternate conveyor uses a fabric belt with a molded facing having integral compressible lugs thereon.

This invention relates to the finishing of workpieces having substantially flat and parallel sides and has for its principal object the provision of a novel combined planer and sander for performing successive finishing operations with greater accuracy and speed than has been possible with prior production machinery.

A more detailed object is to support a workpiece on a predetermined reference plane regardless of any irregularities in the supported side of the work and maintain the position of the latter as it is fed relative to two finishing heads for successive finishing operations with a common and precisely held base.

The invention also resides in the construction of the supporting conveyor and the manner of maintaining the position of the workpiece as it passes through the machine.

Other objects and advantages of the invention will become apparent from the following detailed description taken in connection with the accompanying drawings, in which FIGURE 1 is a perspective view of a finishing machine embodying the novel features of the present invention.

FIGS. 2, 3 and 4 are views showing different types of representative workpieces adapted to be finished with the machine in FIG. 1.

FIG. 5 is an enlarged fragmentary cross-sectional view taken substantially along the line 55 of FIG. 1 with parts broken away for clarity of illustration.

FIG. 6 is a cross-section on a reduced scale taken substantially along the line 6 6 of FIG. 5.

FIG. 7 is an enlarged fragmentary view of part of the conveyor belt.

FIG. 8 is an enlarged fragmentary view of an alternate form of the belt.

FIG. 9 is a fragmentary cross-section taken along the line 9-9 of FIG. 5.

FIG. 10 is an enlarged fragmentary view of part of FIG. 9.

FIG. 11 is a magnified view of the Work surface in FIG. 10.

As shown in the drawings for purposes of illustration, the invention is embodied in a machine for finishing workpieces 16 having substantially flat and parallel sides such 3,379,230 Patented Apr. 23, 1968 as cores composed of relatively cheap material and used as backings for veneers of finer and more expensive material such as walnut. Prior to the application of the veneer, the opopsite sides of the core are planed to substantially fiat surfaces and then are sanded to remove all the slight ridges left by the planer and produce the smooth surfaces required for proper support of the veneer.

The three types of cores shown in FIGS. 2-4 are representative of the different types presently used commercially. Shown in FIG. 2 is a so-called lumber core .10 composed of a plurality of boards 11 disposed in edge-to-edge abutting relation and suitably bonded together. The banded core 10 shown in FIG. 3 is similar to the lumber core but, in addition, has edges covered by strips 11 mitered together at the corners of the core. The third typ illustrated in FIG. 4 is a so-called flakeboard core 19 composed of compressed chips held together by a bonding agent. In each type, the fiat sides of the unfinished core have substantial irregularities in the form of ridges, high spots or hollows that are removed by the planing and sanding operations to provide a flat backing surface for the veneer to be applied.

In the past, veneers typically have been of an inch thick, and of an inch was considered very thin. Now, the scarcity of some woods is leading to the use of veneers as thin as (.020) of an inch. With the advent of thinner and thinner veneers, the flatness of the core finish has become increasingly important because slight high spots in the core produce similar high spots in the veneer itself, and such high spots not only can be evident in the finished product but also result in so-called sand throughs as the veneer is finished after being bonded to the core. Accordingly, it has become necessary to exercise greater care in core finishing and the process is time consuming and expensive. Moreover, it is becoming more and more difiicult to produce the quality of cores that is necessary to avoid excessive spoilage.

The present invention contemplates a novel machine for performing both finishing operations simultaneously and with substantially greater accuracy and speed than have been possible with prior production machinery. To these ends, a planer 12 and a sander 13 are supported on the machine base 14 (FIG. 1) for successive engagement with a workpiece 10 while the latter is supported a resiliently yieldable surface 15 and pressed into the latter to center the workpiece on a predetermined reference plane regardless of any irregularities in the supported side of the work. As the workpiece is fed past the two finishing heads, it is held positively in the same position relative to the reference plane and the heads, and is finished in a plane parallel to the reference plane. Accordingly, the combined machine eliminates the need for separate finishing operations and use precisely the same base for both operations for more rapid accurate finishing.

In this instance, the machine base 14 comprises a rectangular pedestal 17 (FIG. 1) having corner plates 18 resting on the floor, and two spaced parallel columns 19 upstanding from the opposite sides of the pedestal and extending the full length of the latter. The supporting surface 15 is on the upper run of an endless belt conveyor disposed between the columns and trained around horizontally spaced rolls rotatably supported between two elongated side rails 20 extending horizontally along the inner sides of the columns. Herein, the conveyor is formed by two endless chains 21 (FIGS. 5 and 9) disposed in spaced vertical planes with elongated slats 22 perpendicular to the chains disposed in edge-to-edge relation and fastened by screws 23 to laterally projecting flanges 24 (see FIG. 5) on the chain links, and the supporting rolls are formed by front and rear pairs of sprocket wheels 25 fast on parallel shafts 27 which are journaled at their opposite ends in bearings 28 adjacent the front and rear ends of the side rails. The rear shaft is driven by a motor 29 through a drive connection at 30 to drive the chains and advance the upper run of the conveyor belt from front to rear, that is, from right to left in FIG. 9.

The planer 12 comprises a cylindrical head 31 fast on a coaxial shaft 32 which is journaled at the opposite ends of the head in bearings 33 held in bars 34 (FIGS. 5 and 6) extending along the upper ends of the columns .19 and supporting the cutter for rotation about an axis 35 extending transversely of the upper run of the conveyor. Fast on the head are a plurality of teeth 37 which project generally radially outwardly for cutting engagement with workpieces 10 passing beneath the head. It will be seen in FIG. 6 that the teeth are arranged in several rows extending helically around the head and across the full width of the conveyor. To drive the planer, a pulley 38 is fastened to the left end of the planer shaft 32 outside the bearing 33 and is rotated clockwise (FIG. 9) b a belt 39 trained around a similar pulley 40 on the out put shaft 41 of a motor 42 mounted on the outer side of the left column 19 with the motor shaft projecting through the column and extending under the planer shaft. Above the planer is a sharpening wheel 43 (FIG. 9) carried on a nut 44 (FIG. 1) movable back and forth along a threaded traversing shaft 45 and power-rotated by a motor 47 to grind the outer ends of the teeth.

While the sander 13 may take various forms, herein it is a belt sander of the type having a head supporting three parallel rolls 48, 49 and arranged to guide an endless abrasive belt 51 along a generally triangular path, the roll 48 being a contact or pressure roll for pressing the abrasive belt against the work surface while the roll 50 is power rotated to drive the belt along its path. The third roll 49 is urged against the inner side of the belt to tension the latter, and one of the rolls preferably is tilted back and forth about a transverse axis to induce controlled back and forth edgewise travel of the belt. Such sanders are well known to those skilled in the art, and only the basic elements are shown and described herein for purposes of illustration.

Each of the rolls 48, 49 and 50 comprises a sleeve f resiliently yieldable material such as firm rubber covering and bonded to a cylinder 51 (FIG. 9) fixed at opposite ends to a shaft 52 which extends beyond the ends of the cylinder. The pressure roll 48 is disposed between the parallel legs 53 of a yoke 54 with its shaft journaled in bearings 55 (FIG. 6) on the yoke legs and holding the roll at the desired level for engagement of the belt 51 with the work surface. In some instances, the pressure roll is provided with a metal sleeve rather than a yieldable sleeve. The tension roll 49 is spaced 3. short distance above the work path and rearwardly from the pressure roll, and opposite ends of its shaft are journaled on the lower ends of elongated arms 57 suspended from pivots (not shown) above the roll. These arms are spring-urged clockwise about their pivots to maintain the desired tension in the belt. As shown by broken lines in FIG. 5, the drive roll 50 is spaced above the pressure and tension rolls with the opposite ends of its shaft journaled in bearings 58 on supports 59 extending upwardly on opposite sides of the sander from the upper ends of the columns 19. A motor 60 supported on a bracket 61 on the right side of the base is coupled to the right end of the drive roll shaft by a coupling 62 and rotates the drive roll in a direction to drive the abrasive belt 51 in the direction indicated by the arrows in FIGS. 9 and 10. A shoe 56 inside the abrasive belt just to the rear of the pressure roll holds a straight section of the belt against the work. The sander preferably is enclosed in a box-like housing 12 (FIG. 1) having an open lower side.

In the preferred embodiment shown in FIGS. 1, 5-7 and 9, the resiliently yieldable supporting surface of the conveyor is formed by closely spaced rubber blocks 63 (See FIG. 7) fastened to the side of the slats 22 that face upwardly along the upper conveyor run and having fiat and generally rectangular upper faces disposed in a plane parallel to the plane of the upper sides of the slats when the blocks are in relaxed condition. Herein there is one row of such blocks on each slat with the adjacent sides of adjacent blocks spaced apart as shown most clearly in FIGS. 5 and 7. Screws 64 are th eaded into holes (not shown) in the slats through holes in the bottoms of downwardlytapered recesses 65 in the blocks to clamp the blocks in place. Preferably, a fiat metal plate (not shown) is embedded in each block in a plane just beneath the position of the screw head and formed with a hole through which the screw shank projects thereby to reinforce the rubber of the block and distribute the holding force across a substantial portion of the cross-section of the block. As will be seen in FIGS. 7 and 9, the blocks are narrower than the width of the slats so that adjacent rows of blocks also are spaced apart on the conveyor. With the blocks separately mounted on the conveyor, they can be replaced individually in case of damage in service use.

To provide a firm backing for the upper run of the conveyor belt and hold the run in .a predetermined plane, a plurality of elongated parallel bars 67 (see FIG. 5) are spaced apart transversely of the belt immediately beneath the slats 22 and extend longitudinally of the upper run along the tops of transverse braces spanning and rigidly secured to the side rails 20 as shown most clearly in FIGS. 5 and 9. In this instance, each brace comprises a flat upper plate 68 disposed in a horizontal plane beneath the slide bars 67 and suitably fastened to the latter, two end plates 69 depending from the opposite ends of the upper plate along the inner sides of the side rails, and a third plate 70 fastened to the end plates and extending between the latter in a vertical plane centrally of the upper plate with the upper edge of the third plate rigidly bracing the upper plate against downward deflection.

Five such braces are spaced apart longitudinally of the upper conveyor run and supported on the side rails 20 by means of keys 71 (FIGS. 5 and 9) fitted in longitudinal keyways 72 formed in the inner sides of the rails and by screws 73 threaded into the rails through slots 74 in the end plates 69. The end plates rest on the tops of the keys, which are held in the keyways by screws 75, and the screws 73 clamp the end plates against the rails. In this manner, the slide bars 67, the braces and the side rails 20 cooperate to form a bed supporting the conveyor on the machine base 14, and the tops of the slide bars form ways on the bed slidablysupporting the slats 22 of the upper conveyor run with the upper sides of the slats located precisely in a predetermined plane. The upper sides of the slide bars preferably are covered with a layer of anti-friction material.

For precise adjustment of the spacing of the upper conveyor run relative to the planer 12 and the sander 13, this bed is adjustable vertically through an infinite number of parallel positions by means of screw mechanisms at the four corners of the bed operable in unison to raise and lower the bed. As shown most clearly in FIG. 5, the ends of the rails 20 are supported by vertical screws 77 threaded through nuts 78 on the rails. The lower end portions of the screws are rotatably supported in socket cups 79 on the horizontal bottom wall 80 of the pedestal and are keyed to bevel gears 81 meshing with driving gears 82 on cross-shafts 83 journaled on the pedestal. Only one cross-shaft is shown in FIG. 5, but the arrangement at the other end of the machine is similar. All four screws are turned in unison by a drive shaft 84 (FIG. 5) spanning the two cross-shafts and carrying worms 85 meshing with worm wheels 87 fast on the cross-shafts. The drive shaft is driven by a reversible electric motor 88 (FIG. 1) which raises and lowers the bed.

To press the workpieces 10 into the resiliently compressible surface 15 formed by the blocks 63 in front of the planer 12, two pressure rolls 89 in front of the planer are spring-pressed against the top of the workpiece with a preselected approximate force sutficient to preload the compressible surface beneath the workpiece as the latter approaches the planer. Thus, high spots in the underside of the workpiece are pressed into the conveyor surface and the work becomes centered on a reference plane parallel to the planes of the slats 22 and the tops of the bars 67. Herein, each pressure roll comprises a sleeve composed of rubber and having a helical peripheral groove as shown in FIG. 6, the sleeve extending across the full width of the conveyor and being telescoped onto a metal cylinder 90 fast at its ends on a coaxial shaft 91 which extends beyond the ends of the cylinder. At each end of the roll is an arm 92 suspended from a horizontal pivot 93 on the adjacent support bar 34 and urged counterclockwise about the pivot by a coiled spring 94 compressed between an upwardly facing shoulder 95 on the arm and a cover plate 97 overlying the rolls. The spring is guided on a pin 98 telescoped at its lower end into a recess (not shown) in the shoulder 95 and supported at its upper end on the cover plate. With the supporting arms inclined downwardly and rearwardly from the pivots, the springs press the rolls against the workpiece which, in turn, is pressed firmly against the conveyor across the full width of the work.

Just ahead of the planer 12 is a so-called chip-breaker 99 (FIG. 9) in the form of an elongated shoe fast on a transverse shaft 100 rotatably supported on a crossplate 101 depending from the cover plate 97. The chip-breaker is spring-urged counterclockwise about the axis of the shaft 100 and thus is spring-pressed against the portion of the workpiece about to pass the planer, thus serving not only to prevent splitting of the workpiece toward the front but also to maintain the vertical position of the work relative to the reference plane.

It will be seen in FIGS. 9 and 10 that the planer 12 removes a layer of material from the top surface of the workpiece 10 to reduce the thickness of the latter by an amount determined by the spacing of the cutting plane of the planer below the level of the unfinished top surface of the work in front of the planer. For example, this layer may be approximately /4 of an inch thick. As a result of the feeding of the work past the planer, the peripherally spaced teeth 37 inherently produce a slight scalloping of the finished surface as shown in the magnified sectional view in FIG. 11 wherein it will be seen that the planed surface comprises successive arcuate hollows or grooves 102 separated by ridges 103 on the order of .00 1 of an inch above the bottoms of the hollows. The exact configuration will vary with the speed of rotation of the cutter, the spacing of the teeth, and the rate of feed of the work. As used herein, cutting plane means the plane of the top surface of the work after it passes the cutter, disregarding the grooves 102.

To maintain the position of the workpiece 10 relative to the reference plane beyond the planer 12, a pressure plate 104 is supported between the heads with its flat underside 105 level with the cutting plane of the planer, its front edge closely adjacent the planer, and its rear edge closely adjacent the area of contact between the abrasive belt 51 and the work. This plate is rigidly supported on an upright framework 106 which ma be made selectively adjustable, if desired. Accordingly, the pressure plate cooperates with the pressure rolls S9 and the chip-breaker 99 in positioning the work relative to the planer as well as holding the position as the work approaches the sander. Beyond the pressure roll 48 of the sander is a rear pressure plate 107 supported cantilever fashion on the lower end of a crossplate 108 with a narrow downwardly facing surface 109 of this pressure plate disposed in the finishing plane of the sander close to the line of departure of the belt from the work. The sander at least removes the ridges 108 left by the planer and may reduce the surface of the work from .001 to .020 of an inch below the planers cutting plane. Thus, the rear pressure plate will be positioned this much closer to the reference plane than is the front pressure plate to maintain the position of the workpiece beyond the sander.

Thus, it will be seen that the pressure rolls 89 effect the initial preloading of the conveyor surface 15 and positioning of the work for the pass through the machine, and this positioning is maintained primarily by the pressure plates 104 and 107 in cooperation with the conveyor blocks 63 which hold the upper surfaces of the workpiece against the plates. Of course, the pressure roll 48 of the sander 13 assists in holding down the portion of the work immediately beneath this roll, and the cutter teeth 37 have a limited holding effect. In this regard, it should be noted that the helical arrangement of the cutter teeth is much better than angularly spaced straight rows of teeth because there always are several teeth spaced across the length of the planer head always in engagement with the work to avoid a pronounced impact-and-release effect that would be produced by such straight rows. The result could be an up-and-down motion of the work beneath the planer of sufiicient magnitude to hamper the accuracy of the machine.

Shown in FIG. 8 is an alternate form of the conveyor that may be substituted for the chain, slat and block construction described above. Instead of the chains 21 and slats 22, this form uses an endless belt 110 cornposed of flexible fabric, and the blocks 63 are replaced by a molded facing 110 formed with closely spaced and integrally joined lugs 111 projecting upwardly from the ribbed and grooved base layer which is bonded to the fabric. When such a belt is used, it is backed by a wide and flat bedway (not shown) in place of the slide bars 67, and supported on cylindrical rolls instead of the sprocket wheels 25. The operation of the machine remains the same although the conveyor surface may be somewhat softer than that provided by the blocks 63.

I claim as my invention:

1. A combined planing and sanding machine for finishing workpieces having substantially flat and parallel sides, said machine comprising a base, an endless conveyor on said base having a straight run for engaging one side of the workpiece and advancing the latter along said run with the opposite side of the workpiece facing away from the run, said conveyor including an endless longitudinally flexible belt supported in a predetermined plane along said run and having resiliently compressible surface elements thereon engageable with the workpiece, a planer spaced from said run and supported on said base for rotation about an axis extending transversely of the run, said planer having blades arranged to pass a first preselected distance from said plane for rough finishing of the workpiece along a cutting plane, a sander spaced longitudinally of said run from said planer and including a contact roll supported on said base for rotation about an axis extending transversely of the run and positioned beyond said planer to support an abrasive element a second preselected distance from said plane less than said first preselected distance for finishing engagement with the workpiece after the later is planed, means in advance of said planer for pressing the workpiece toward said run and exerting a preloading force on said surface elements to center the workpiece on a reference plane parallel to said predetermined plane regardless of irregularities in said one side, and means for holding the preloading of said surface elements as the workpiece passes said cutter and said contact roll including a hold-down member disposed between the cutter and said contact roll and having a holding surface in said cutting plane.

2. A combined planing and sanding machine for finishing workpieces having substantially flat and parallel sides, said machine comprising a base, an endless conveyor on said base having a straight run for engaging one side of the workpiece and advancing the latter along said run with the opposite side of the workpiece facing away from the run, said conveyor having a resiliently yicldable surface engageabie with the workpiece, a backing supporting said run in a predetermined plane, planing and sanding heads spaced apart longitudinally of said run and mounted on said base for successive engagement with said opposite side as the workpiece is advanced along said run, said planing head being positioned in advance of said sanding head for rough removal of material from the workpiece prior to sanding thereof, means for pressing the workpiece toward and into said conveyor in advance of said planing head to preload said yieldable surface beneath the workpiece, and additional means for holding the workpiece against the conveyor and maintaining the loading of said surface as the workpiece passes both of said heads whereby the workpiece initially is centered on a reference plane parallel to said predetermined plane despite irregularities in said one side and is maintained in position while passing both of said heads.

3. The combination defined in claim 2 in which said pressing means comprises at least one pressure roll rotatably supported on said base, extending across said run in advance of said planning head, and yieldably urged toward said conveyor to exert a preselected approximate preloading force on the conveyor through the workpiece.

4. The combination defined in claim 2 in which said additional means includes a pressure plate rigidly supported on said base and having a flat holding surface in the cutting plane of said planing head between the latter and said sanding head whereby said preloaded surface holds the workpiece against the plate.

5. The combination defined in claim 4 in which said holding surface substantially covers the space between said heads.

6. The combination defined in claim 4 in which said additional means includes a second pressure plate beyond said sanding head and having a holding surface closely adjacent the area of contact of the sanding head and in a finishing plane parallel to said cutting plane and spaced inside the latter an amount equal to the thickness of material removed by the sanding head.

7. The combination defined in claim 2 in which said conveyor comprises a plurality of elongated and substantially rigid slats joined together in the form of an endless belt, and a plurality of closely spaced blocks on said slats composed of resiliently compressible material and having outer faces disposed in a common plane when the blocks are in relaxed condition.

8. The combination defined in claim 7 in which said backing is a bed having a slide way extending longitudinally of said run and supporting said slats in said predetermined plane.

9. The combination defined in claim 2 in which said conveyor is a belt composed of flexible fabric and said surface is formed by a facing bonded to said belt and having closely spaced resiliently flexible lugs thereon.

10. The combination defined in claim 2 in which said planing head has blades arranged in a plurality of helical rows whereby several blades spaced across the head are in contact with the workpiece at all times.

11. A machine for finishing a workpiece having substantially flat and parallel sides, said machine comprising a base, a support on said base for engaging one side of the workpiece with the opposite side thereof facing away from said support, said support having a resiliently yieldable surface engaging the workpiece, a planing head and a sanding head spaced apart along said support and positioned for successive engagement with said opposite side, means mounting said support and said heads on said base for feeding movement of said support relative to said heads thereby to feed the workpiece past the heads, said planing head being positioned in advance of said sanding head, and means for pressing the workpiece toward and into said surface to preload the latter and maintain the position of the workpiece as it passes said heads, said last mentioned means including at least one yieldably supported pressure member in advance of said planing head to center the workpiece on a reference plane despite irregularities on said sides.

References Cited UNITED STATES PATENTS 2,732,867 1/1956 May et al. 144-117 XR FOREIGN PATENTS 1,197,429 6/1959 France.

' WILLIAM W. DYER, 1a., Primary Examiner.

W. D. BRAY, Assistant Examiner.

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