US3538968A - Method and apparatus for making cuts of precise depth - Google Patents

Description

D United States Patent 1 3,538,968

[72] Inventor William Gluck 3.322.171 5/1967 Cornell 144/ 136 Box 315, Monroeville, Pennsylvania 15146 3,420,142 1/1969 Gale et a1 .1 144/ l 36 [21] Appl No. 717,178 [22] Filed March 29, 1968 Primary Examiner-Gerald A. Dost [45] Patented Nov. 10,1970 Attorney-Buell, Blenko & Ziesenheim [54] METHOD AND APPARATUS FOR MAKING CUTS 0F PRECISE DEPTH 36 Claims, 29 Drawing Figs.

[52] US. Cl 144/323, ABSTRACT: I disclose cutting apparatus comprising a l 44/2, 144/136 tively rigid support, a reference member formed on said sup- [51] Int. Cl B27f l/04 pol-t so that relatively thin material to be out can be bent or [50] Field Of Search 144/309, bowed slightly on at least i of said referencemember to 30 -1 322, 243), ensure contiguous contact therewith, cutting means jux- 133, 136 taposed above said reference member for cutting said material to a precise de th relative to said reference member, said [56] References C'ted reference meml er being so disposed that the weight of said UNITED STATES PATENTS material slightly bows or bends said material over said l.623,020 3/1927 Norris 144/136 reference member and on at least one side thereof.

Pagn'ted'Ncv; 10,1970 I 3,538,968

H15 ATTORNEYS Patented Nov. 10, 1970 Sheet 4 M6 INVE/VWOI? Patented Nbv. 10, 1970 Sheet 0! 6 :O OOO QNK METHOD AND APPARATUS FOR MAKING CUTS F PRECISE DEPTH The present invention relates to method and apparatus for making cuts of precise depth, and more particularly to apparatus of the character described for making the grooves and/or other cuts in sheet material to permit the production of mitered joints therein without completely severing the material at such joints.

Specifically, the invention relates to apparatus for accurately cutting a V-groove or the like into the back of sheet material, with the bottom of the V-groove extending a closely controlled few thousandths of an inch to a finished surface of the front side of the sheet material so that the sheet material can be folded to form mitered joints without severing or marring the finished surface at the miter. in the mitering operation, the wall surfaces of the V-groove or the like are juxtaposed or brought together for gluing or other securance means to provide a mitered outside joint or corner in the sheet material without gaps or ragged edges at the mitered joint and without refinishing the joint. With this type of mitered joint the i finished surface of the sheet material extends in uninterrupted fashion over the exposed corner of the mitered joint.

My invention is particularly useful for cutting or milling one or more grooves or other cuts of various shapes into sheet material such as laminated wood, composition or chipboard,

.masonite, and similar materials coated with vinyl plastic, formica, or other decorative layer. Similarly, my invention is useful for folding or mitering veneered panels conventionally used in making furniture and the like. Both inside and outside corners can be made with little difficulty with the aid of my novel cutting apparatus.

In the furniture industry, particularly in the manufacture of contemporary furniture many inside and outside corners are frequently used for decorative effect. My present invention permits a series of inside and/or outside corners to be made in a single piece of material by cutting and folding a veneered panel or the like. This is done without the necessity of completely severing and refinishing the material at such corners. These mitered joints are formed by bending the sheet material along the very thin section or web left between the deepest part of the groove and the opposite or finish side of the panel. In so doing the surfaces of the groove are coated with glue and brought into substantial contact and clamped in the usual manner untilthe mitered joints thus formed are dry. The resulting joints are neat and clean in appearance and require no further finishing.

In order to produce a mitered joint in this manner it is imperative that the very thin residual material or web between the bottom of the groove and the finished side of the sheet or panel or board be of uniform thickness. With uniform thickness, breaks in the finished surface at the mitered joint are avoided when the material is folded or mitered to produce the joint.

Previously proposed apparatus for this purpose, for example as disclosed in the Cornell, US. Pat. No. 3,322,171, exhibits considerable difficulty in setting up and adjusting the apparatus and does not produce the desired uniformity of residual finish or web thickness at the bottom of the groove, particularly when relatively long boards or panels are grooved. The Cornell apparatus utilizes a vertically adjustable rotary blade juxtaposed to a vertically adjustable shoe engageable with the finish side of the panel for determining the residual thickness. To compensate for the rather wide manufacturing tolerances of most sheet and panel materials, the shoe must be adjusted to produce a dished depression in the material particularly when in sheet form.

The Cornell shoe is of a rigid material and in consequence an overhanging portion of the sheet material or board causes the shoe to penetrate slightly into the finish side ofthe panel to vary the residual thickness between the finish surface and the bottom of the groove. The absence of a fixed reference frame in the Cornell apparatus prevents the simultaneous operation of a plurality of cutters upon a single board or panel. If multiple cutters andshoes therefore were provided, a change in panel depression caused by adjustment of one shoe would vary the adjustments previously imparted to the one or more adjacent shoes likewise engaging the board or panel. Similarly the dished depression produced by the Cornell shoe would render inaccurate the use of a single, wider cutting head having parallel-spaced cutting surfaces.

A cutting machine arranged as disclosed in the Cornell patent has been observed to produce variable web thickness adjacent the finished surface of a sheet or panel. The web was observed to increase from the central area of the board toward either end thereof along the groove. That portion of the board overhanging the table of the Cornell apparatus acts as a variable moment arm against the aforementioned shoe when a board or panel is moved through the apparatus. The shoe is then caused to be depressed slightly but varyingly into the surface of the board or panel as the material is drawn through the apparatus.

There are of course other known apparatus for producing one or more grooves in a sheet or panel. In the Lade, US. Pat. No. 2,907,359 multiple grooves are cut into the finished side of a sheet or panel for decorative effects, for example to simulate boards of variable widths in the panel or sheet. The grooves cut by the Lade machine are relatively shallow and the depth thereof need not and cannot be accurately determined, relative to the reverse side of the panel. As the supporting table for the Lade apparatus is slotted to receive portions of the cutters projected therethrough, the distances between the cutters cannot be varied. Thus, the Lade apparatus, although satisfactory for its intended purpose, cannot produce the results provided by my invention.

The apparatus described in the Onsrud, US. Pat. No. 2,168,234 includes a table for upon which a panel or sheet material is securely clamped. A plurality of cutters are employed to cut in a single groove of asymmetric cross section. The panel is then bent or folded to produce a single outside rounded corner of relatively large radius. The Onsrud machine is not capable of performing the several functions of my novel cutting apparatus. Moreover, the Onsrud machine exhibits substantially the same disadvantages of the Cornell device insofar. as making cuts of very accurate depth or web thickness relative to the finish surface of the sheet or panel. In this connection Onsrud does not provide a proper frame of reference for precisely gaging the thickness of the web or residual finish material at the bottom of the groove. Although the sheet or panel material is clamped to a planar surface it is improbable, from known manufacturing tolerances, that every portion of the material surface directly beneath the cutters will be maintained flushly against the Onsrud table.

I overcome these disadvantages of the prior art by providing novel cutting or grooving apparatus having an accurately placed frame of reference juxtaposed to cutting and holddown means for the material which are therefore arranged on the same side of the sheet, panel member or board being cut by my apparatus. The cutter can be very accurately adjusted relative to the fixed frame of reference, and means are afforded by my invention for ensuring contiguous contact between the material being cut and the frame of reference. Thus, although my apparatus is of general utility, a very thin but uniform web thickness can be afforded adjacent the finished side of the material being cut, which cannot be accomplished with previ ous cutting machines.

My cutting apparatus is so arranged that multiple adjustable cutters can be employed and adjustments made therein without affecting the adjustment of the remaining cutters. The cutting apparatus of my invention is further arranged to permit adjustment in lateral spacing between the cutters and to permit the use of one or more cutting heads having multiple cutting edges or multiple cutting blades. My apparatus is further arranged so that overhang of the material being cut does not impart a moment of force to the fixed frame of reference of my machine. In a particular form of my machine having multiple Cutters, I employ double-ended spindles, i.e., with a cutting blade adjacent each end of the spindle. The

spindle can be pitched or deflected about an axis transverse to the spindle shaft for individual adjustment of the cutting blades relative to a reference member, to compensate for manufacturing tolerances in the spindle cutting blades and other components.

In another specific arrangement of my cutting apparatus for making multiple grooves, I provide means for preventing a spring-Ioadedfence from collapsing the sheet or panel at the aforementioned web areas when the latter are very thin. One form of such anticollapse means includes a shoe or the like capable of riding in the cut or groove to spread the walls thereof. I also provide a novel feed arrangement for my novel cutting apparatus.

I accomplish these desirable results by providing cutting apparatus comprising a support, at least one elongated reference member formed in said support and projected slightly from adjacent surfaces of said support means for urging material to be cut by said apparatus against said reference member and slightly around at least one side ofsaid reference member, and cutting means for said material juxtaposed to said reference member for cutting said material to a predetermined closely spaced distance from said reference member.

I also desirably provide similar cutting apparatus wherein said urging means include roller means juxtaposed to said reference member and engageable with said material to urge said material against and slightly around at least one side of said reference member.

l also desirably provide similar cutting apparatus wherein said apparatus includes a supporting rail mounted in generally parallel-spaced relation relative to said reference member, and said cutting means and said urging means are slidably mounted on said rail.

I also desirably provide similar cutting apparatus wherein a second reference member is similarly formed in said support and extends generally parallel to said first-mentioned reference member, additional cutting means and urging means are juxtaposed to said second reference member, and said additional cutting means are capable of staggered adjustment relative to the first-mentioned cutting means for making closely spaced or overlapping cuts in said material.

I also desirably provide similar cutting apparatus wherein a pair of material feed mechanisms are mounted on said mechanisms along said support.

l also desirably provide a method for making cuts of precise depth, said method comprising the steps of establishing a frame of reference, urging one side of material to be cut into flush engagement with said reference frame, and cutting the other side of said material to a depth disposed a precisely predetermined distance from said reference frame.

During the foregoing discussion, various objects, features and advantages of the invention have been set forth. These and other objects, features and advantages of the invention together with structural details thereof will be elaborated upon during the forthcoming description of certain presently preferred embodiments of the invention and presently preferred methods of practicing the same.

In the accompanying drawings l have shown certain presently preferred embodiments of the invention and have illustrated presently preferred methods of practicing the same, wherein:

FIG. I is an isometric view ofone form of cutting apparatus arranged in accordance with my invention;

FIG. 1A is a partial vertically sectioned view of the apparatus as shown in FIG. I and taken along reference line IA-IA thereof;

FIG. 18 is an isometric view ofa modified cutter usable with the apparatus ofeither FIG. I or FIG. 7;

FIG. 2 is a cross-sectional view ofthe apparatus as shown in FIG. I and taken along reference line II-ll thereof;

FIG. 2A is an enlarged partial view of the roller as shown in FIG. 1 and of adjacent components;

FIG. 2B is a partial cross-sectional view similar to FIG. 2 but illustrating a modified holddown roller and reference member arrangement;

FIG. 2C is a partial view similar to FIG. 2 but illustrating an improperly shaped reference member;

FIG. 2D is a similar view showing another form of cleaning means for the finish surface of a sheet or panel;

FIG. 3 is a sectional view showing a representative cut made by my apparatus;

FIG. 4 is a partial longitudinally sectioned view of the apparatus as shown in FIG. 1 and taken along reference line IVIV thereof;

FIGS. 5A, 5B, 5C, SD, 5E, 5F, and 5G represent various forms of reference members which can be used with my apparatus in determining the depth of cut and more importantly the web thickness at the grooves or cuts in the material, particularly when used for mitered joints; FIG. 5D additionally discloses one form of material feeding arrangement for use with my invention;

FIGS. 6A, 6B, 6C and 6D illustrate various types ofcuts and joints produced by means of my apparatus and a modified cutter for use with my cutting apparatus;

FIG. 7 is an isometric view ofa multiheat cutting apparatus arranged in accordance with my invention and additionally depicting material feeding means which can be employed with my novel cutting apparatus as shown in either FIGS. 1 or 7',

FIG. 7A is a partial vertically sectioned view taken along reference line VIIA-VIIA of FIG. 7;

FIG. 7B is a right side elevational view of the apparatus as shown in FIG. 7A and taken generally along reference line VIIB-VIIB thereof;

FIGS. 8A, 8B and 8C are typical of various decorative shapes that can be produced from a single piece of material 30 or 30' with the aid of my novel cutting apparatus; and

FIGS. 9 and 10 are cross-sectional and enlarged partial isometric views respectively of a cutting apparatus generally similar to that shown in FIG. 7 but illustrating modified driving means for the cutting heads.

Referring now to FIGS. I, IA, 2 and 4 of the drawings, the illustrative form of my novel cutting apparatus shown therein comprises a bench or table 22 having an upper substantially planar surface 24 on which adjustable spring-loaded fence 26 is mounted and an adjustable but rigid fence 28. The fences 26, 28 can be spaced to closely receive a board, sheet or panel 30 or similar material therebetween for movement through the cutting apparatus 20 in the direction denoted by arrow 32.

The rigid fence 28 is readily adjusted longitudinally the table 24 as denoted by double-headed arrow 34 by means of a pair of screw shafts 36, 38 handwheel shaft 40 and suitable gearing trains 42, 44. The spring fence 26 can likewise be moved longitudinally of the table 24 by a suitable screw adjustment at each end. one of which is denoted at 46. Each fence 26 or 28 is notched at 48 or 50 respectively to permit passage over longitudinal ridge 52 formed in the top surface 24 of table 22 for purposes described below. At least the feed side of the reference ridge 52 is provided with a ramp or camming surface to earn the leading edge 55 of the material 30 thereovcr.

At the end of the table 22 a standard 54 or 56 is affixed in substantial alignment with the longitudinal ridge 52. A longitudinal, contoured supporting bar 58 is extended between the upper end portions of the standards 54, 56 and is secured thereto by suitable connecting brackets. In this arrangement of the invention, a dual cutting head 60 and a pair of holddown roller heads 62, 64 are depended from the supporting bar 58 and are slidably mounted as better shown in FIGS. IA and 2 respectively.

The dual cutting head 60 includes in this example a doubleended spindle 66 having a cutter 68 or 70 mounted adjacent each end thereof as better shown in FIG. 4. Drive motor 72 is mounted on bracket 74 which desirably is pivoted for belt-tensioning purposes. The bracket 74 is pivoted to vertical slide plate 76 which is slidably secured to housing 78 of cutting head 60 by means of brackets 80 and vertical adjustment screw 82 bearing against supporting bar 84, which is rigidly secured to housing 78.

Spindle housing 86 is pivotally secured to depending tongue 88 formed in this example integrally with the vertical slide plate 76, by means of pivot and lock assembly 90. Transmission belt 92 is coupled to motor pulley 94 and to a similar pulley or sheave (not shown) on spindle 66. The pivot and lock assembly 90'extends through the aforementioned slide plate tongue 88 and plate 91 forming part of the spindle housing 86. To align the cutters 68 and 70 with the top surface 24 of table 22 and more particularly with the reference ridge 52 the spindle housing 86 can be adjustably pivoted about slide plate tongue 88 by means of pivot adjustment screws 96, 98.

The cutter heads 60 can be driven along the length of supporting bar 58 by means of rack 100 secured in this example to the undersurface of the upper flange 102 of the supporting bar 58 and a pinion 104 rotatably mounted on the cutter head 60 and rotated by handwheel 106. From the structure of the cutting head60 described thus far, it will be seen that the spindle 66 and cutters 68, 70 can be adjusted vertically and longitudinally of the table 22 and further can be pivoted for horizontal alignment of the spindle and cutter with the ridge 52 or other frame of reference. The cutting head 60 can be clamped or fixed at any point along the length of the supporting bar 58 by means of a clamp and lock assembly denoted generally by reference character 107 and detailed in FIG. 1A of the drawings.

Each holddown roller head 62, 64 includes a vertical standard 108 slidably mounted on the supporting bar 58 as better shown in FIG. 2 of the drawings. A fixed bracket 110 and a pivoted bracket 112 are spacedly secured to the standard 108. Roller 114, is in this example, urged downwardly toward the surface 24 of the table 22 by means of a tensioned coil spring 116 secured to the opposite end of the pivoted bracket 112. Spacing of roller 114 relative to the table surface 24 or ridge 52 is controlled by adjustment screw 118 in order to accommodate different thicknesses of material 30.

Where multiple grooves or cuts will be made in the material 30 by repeated passes thereof through the cutting apparatus (either with the position of the material reversed I80 or with the cutting head 60 adjusted laterally) means can altematively be provided for preventing collapse and possible damage of the very thin webs at the bottoms of the previous cuts or grooves. One form of such anticollapse means includes one or more pairs of spreader bars slidably mounted upon the supporting bar 58, with one such pair 120, 122 being illustrated in this arrangement of the invention. Each spreader bar 120 or 122 is supported from a vertical standard 124 or 126, which is slidably clamped in the adjacent T-slot (FIG. 1A) 128 or 130 on either side of the supporting bar 58. In this example a pair of spreader bars 120, 122 desirably are utilized to accommodate the angulation or bowing of a sheet or panel 30 as it passes over the ridge 52, as better shown in FIG. 2 of the drawings. The function of the longitudinal ridge 52 in affording an accurate frame of reference for determining the web thickness of the cuts or grooves made by cutters 68 or 70 will presently be described. Where an equivalent frame of reference is provided in the plane of the table surface 24 in accordance with a modification of my invention, the pair of spreader bars 120, 122 can be replaced by a single or continuous bar (not shown).

As viewed in FIG. .2 of the drawings the holddown roller or rollers 114 are poised directly above the longitudinal ridge 52. The roller 114 desirably is faced with rubber or other elastomeric material of suitable resiliency. Desirably the resiliency of the roller 114 is such that its footprint area 132 is wider than the width 134 of the ridge 52, as better shown in FIG. 2A or otherwise extends a substantial distance on either side of the reference member. This arrangement, together with the weight of the material 30 (where the reference member projects above the surrounding table surface) has the effect of slightly bowing or bending the material over the ridge 52. In many cases material weight only will be sufficient bending means, depending on the direction of cutter rotation. Thus, in FIG. 1, rotating of the cutter blade 68 or 70 in the counterclockwise direction (arrow 135) coupled with movement of material 30 from left to right (arrow 32) will cause the cutter blade itself to exert downward uponthe material 30. In the latter case, the adjacent roller 114 and associated components can be eliminated in many applications, with a caveat of careful feeding of the material 30, however.

In the event that a wider ridge 52 is desired as shown in FIG. 28, a pair of holddown rollers 136 can be substituted for the holddown roller 114 to prevent a fulcruming or lever action of the sheet 30 about one of the ridge edges 138 or 140.

By slightly bending or bowing the material 30 over the longitudinal ridge 52 the flush contact between the material and the ridge 52 or other reference member constituting the frame of reference, is assured along the length of the reference member and such contact is further assured particularly in the area adjacent the cutter 68 or 70 by the provision of the holddown roller 114, or alternatively the pair of holddown rollers 136. Accordingly, a very accurate and uniform web thickness can be maintained along the entire length of the groove or other cut in the material 30. Such web thickness is denoted by dimensional arrows 137 in FIG. 3 of the drawings. In the case of material 30 having a vinyl coating 139 or other very thin plastic finish or veneer it is obvious that the web thickness 137 must be closely controlled.

As better shown in FIG. 2C of the drawings, it is desirable that the total footprint area or areas of the rollers 114 of 136 be substantially wider than the width of the longitudinal ridge 52. Otherwise, as shown in FIG. 2C the material being cut will tend to pivot near its end about one of the edges [1 of the wide ridge c. A small roller d with a small footprint area would possess insufficient moment arm denoted by dimensional arrows e to hold down the end portion of the material 1.

Referring again to FIGS. 2 and 2A, the leading edge 138 of the longitudinal ridge 52 serves also to remove dust and other foreign material that may cling to the under or finished surface of the material 30. If desired, a duct 142 can be extended through the table top 24 to communicate with space 144 between the table top 24 and the slightly bowed sheet material 30. The duct 142 is coupled to the suction inlet of a suitable blower (not shown) for removing such foreign material.

Another form of cleaning means is shown in FIG. 2D. An elongated rotary brush 141 is mounted for rotation within recess 143 in the table 22'. The brush protrudes above the table top 24' sufficiently to engage the material 30. Means (not shown) are provided for rotating the brush 141, which can extend the length of the table top 24', and for applying a partial vacuum, through duct 145, to the recess I43 and the space 144' between the material 30' and table top 24'. Thus, the duct 144 can be coupled to the suction part of a suitable blower (not shown) for withdrawing any dislodged foreign material.

It will be readily understood that space 144 is not essential to the removal of foreign matter by brush 141 and the suction applied in the vicinity thereof by box 143, or that the brush and box need be located upstream of the reference member. Thus, the cleaning arrangement of FIG. 2D can be associated with space 144' of FIG. 5A or either space 144 of FIG. 5D. Alternatively, the FIG. 2D device can be utilized at those areas of flush engagement between material 30' and work table 22' as shown in FIGS. 5A, 5C and 5E.

Other equivalent means can be substituted for the ridge 52 forming the frame of reference described in the preceding FIGS. Thus, in FIG. 5A of the drawings, a frame of reference is provided by a stepped table surface 146. Holddown roller 114' desirably is mounted directly above the step 146 in the table surface 24'. If desired, the subsequent area 148 of the table 22 can be tapered upwardly to the original level 24' of the table surface so that the material 30' remains substantially flat upon the table 22'. In any case roller 114' bends the material 30' slightly around one side of the step 146 to ensure contingent contact.

In FIG. 5B the aforementioned frame of reference is afforded by a sunken ridge 150 provided by cutting two relative- Iy wide and shallow grooves 152, 154 on either side of the sunken ridge. The grooves 152, 154 are of sufficient width that the material 30' is bowed or rippled very slightly around either side of the ridge 150 by pressure of holddown roller 114'. The top of the ridge 150 can he flush with the remainder of the table top 24' (beyond grooves 152, 154) so that material 30 lics substantially flat on the table 22'.

In FIG. C the aforementioned frame of reference is afforded by two angularly disposed plane surfaces 156, 158 forming the table top 24' and intersecting at an angle of slightly less than 180. The line of intersection, denoted by reference character 160, provides the aforementioned reference member with contingent contact therewith by the sheet material 30' being ensured by the slight bending or bowing of the material over or slightly around the intersectional line 160 aided by one or more holddown rollers 114.

The frame of reference of FIG. 51) of the drawings is afforded by a table 22 having a relatively deep longitudinal groove 162 extending centrally along the length of the table top 24'. An elongated hard-surfaced roller 164 is rotatably mounted in the groove 162 and extends a short distance above the surrounding surface 24 of the table 22' to provide a reference member. The roller 164 can be fabricated from steel or other hard structural material and polished to prevent marring ofthe finish or undersurfacc of the panel 30'.

If desired the roller 164 can be supported throughout its length by a backup member 166 supported in hearing contact with the roller 164. The backup member 166 if used is afforded a concave surface for complementary engagement with the face of the roller 164. In such case, the leading edge 168 of the backup member 166 acts as a scraper to maintain the roller 164 in a clean condition by removing any foreign material collected thereon through contact with the sheet or panel 30'. If desired, the roller 164 can be positively driven to at least aid in feeding the material 30' through the cutting apparatus. Desirably also the footprint area of resilient holddown roller 114 extends substantially on either side of the essentially line contact of material 30' with the rigid roller 164 to aid in bending or bowing the material 30 slightly around the roller 164 to effect a frame of reference for making very accurate grooves or other cuts with cutter 68'.

In FIGS. 55 and SF the reference member is afforded by perforate section 161 of a completely planar tabletop 24. One or more cutters 68' are mounted for movement along and, in this example, directly above the perforate area 161, Suction is applied to box 163 through duct 165 to apply holddown force to the material 30. This holddown force causes the finish or undersurface of the material to flushly engage the perforate section 161 adjacent the cutter 68' so that a very accurate cut can be made relative to a fixed frame of reference, 1.0., the perforate section 161. The length of the suction box 164 can be effectively varied to accommodate differing widths of material 30 on table 22' by movement of push bar 167 inscrted into the otherwise open end 169 of the suction box 163.

Still another form of the reference member 52" is shown in FIG. 5G ofthe drawings. FIG. 5G illustrates cutting apparatus which is generally similar to that shown in FIG. 4 of the drawings. In this example, however, the table 22" is provided with a slightly arcuate reference ridge 52" projecting above the table surface 24". The arcuate contour of the reference ridge 52" is exaggerated in FIG. 5G and for most materials the ridge 52" is varied in height from about 0.005 to 0,015 inch per lineal foot of table and reference ridge length, which, as better shown in FIGS. 1 and 7 of the drawings, extend transversely of the direction of material travel. The height (denoted by arrow 52"a) ofthe ridge 52" at its midpoint, therefore, will vary depending upon the thickness ofthe material The material 30", as it is passed through the cutting machine 20", is subjected to a compound deflection or curvature, albeit slight. The curvature of the sheet material 30 along the reference ridge 52" overcomes the effect of any slight warpage, which occurs frequently in several types of sheet materials, and ensures contingent contact between the ridge 52" and the sheet material 30". Moreover in manufacturing my novel cutting apparatus 20", it is easier to machine an arcuate ridge 52" than a perfectly straight one. It is also contemplated that the reference members illustrated elsewhere herein, for example the roller member of FIG. 5D or the stepped table surface of FIG. 5A, likewise can he provided with an arcuate height such as denoted at 52"a in FIG. 5G.

In several types of easily bent sheet materials the weight of the sheet is sufficient to ensure bending thereof transversely along the arcuate reference ridge 52" as shown in FIG. 56 and also longitudinally so as to engage opposite edges or surfaces of the table 22 or 22 as shown in FIG. 2 or FIGS. 5A through 5D. In other cases, and also to prevent inadvertent displacement of the sheet material 30", a pair of holddown rollers 114" are mounted so as to engage the sheet material 30" adjacent each end of the reference ridge 52". One or both of the rollers 114" can be adjusted for movement along the ridge 52", for example in the manner illustrated in FIG. 1 or in FIG. 7, to accommodate differing heights of sheet material 30". A cutter assembly denoted generally by the reference character 60" can be similarly mounted.

In the arrangement of FIG. 5G it is not necessary to dispose a holddown roller closely adjacent the cutter 68 as shown elsewhere in the drawings. As noted before, the arcuate contour of the reference ridge 52" ensures contingent contact along the entire length of the ridge with the sheet material 30 and particularly in the area of the cutter 68".

This arrangement permits greater freedom of movement of the one or more cutter assemblies 60". The rollers 114" otherwise are constructed similar to the rollers 114 or 114' shown elsewhere in the drawings. In particular, the rollers 114" are provided with the large footprint areas relative to the width of the ridge 52" to ensure bending of the sheet material 30 in the longitudinal as well as in the transverse direction.

Referring again to FIG. 1 and related FIGS. of the drawings, it will be understood that a single groove can be cut into the material 30 by removing one of the cutters 68 or 70 from the double-ended spindle 66. It will also be understood that a single-ended spindle and cutter (not shown) can be provided. This distance between the cutters 68, 70 can be varied by means described below.

With reference now to FIGS. 1B and 6A--6D, a few of the many possible mitered and other joints that can be made with the aid of my novel cutting apparatus will now be described. FIG. 6A for example shows a sectional view through material 30 having a double V-groove 170-172 therein. The groove 170-172 can be cut by a single suitably shaped cutter, for example the cutter 174 of FIG. 1B or by staggered front and rear cutters of FIG. 7. The material 30' of FIG. 6A can be utilized to form a reentrant mitered joint 176 of FIG. 68, by folding and gluing to permanently close the V- grooves 170, 172. As the grooves 170, 172 do not penetrate entirely through the finish material 178 on the panel 30' the finish material 178 remains intact entirely around the reentrant, mitered joint 176. The corners 180-182, therefore, need not be refinished.

The uninterrupted finish layer 178 also serves to position the segments 184, 186, 188 comprising the joint 176 to facilitate assembly thereof.

If desired, a rectangular groove 190 can also be cut in the sheet material 30 as better shown in FIG. 6A for the purpose of accommodating a second structural member or panel 192 by way of a conventional tongue-and-groove joint as better shown in FIG. 6B of the drawings. If desired the multiple cutter of FIG. 18 can be afforded an appropriately shaped cutting edge for making the rectangular groove 190.

A similar but more complicated reentrantly mitered joint is illustrated in FIGS. 6C and 6D of the drawings. In the latter example the reentrant segments 194, 196 and 198 are of reduced thickness as afforded by raised portion 200 of cutter 202. The mitering grooves of the material 30, as better shown in FIG. 6C, are made by a plurality of appropriately spaced cutting ridges 204 on the raised cutter portion 200. The cutter 202 can also be provided with a rectangular cutting surface 206 for cutting a rectangular groove 208 in the material 30 for a conventional tongue-and-groove joint with an additional structural member 192 as noted in the preceding FIGS. The reentrant mitered joint of FIG. 6D is otherwise formed with equal facility, as described above in connection with FIGS. 6A and 6B.

Another basic form of my novel cutting apparatus 210 is illustrated in FIGS. 7 and 7A and is useful for the simultaneous cutting ofa plurality of grooves or other cuts in sheet or panel material 30'. The cutting apparatus 210 also illustrates the provision, in accordance with my invention, of laterally movable or adjustable automatic feed means forming in this example parts of a pair of laterally adjustable fence and feed mechanisms 212, 214 for the material 30', which is fed through the cutting apparatus 210 in the direction denoted by arrow 32'. The combined fence and feed mechanisms 212, 214, which will be described in detail presently, also can be used with my novel cutting apparatus described in connection with preceding FIGS.

The cutting apparatus 210 includes a table or bench 216 having in this example a substantially planar top surface 218. At each end of the table 216 a number of uprights or supports 220, 222 are provided. It will be understood as this description proceeds that additional uprights can be utilized if desired. Between each pair of uprights 220 or 222 a supporting rail 224 or 226 is supported adjacent the upper ends of the uprights. The supporting rails 224, 226 can be secured to the respective uprights by suitable brackets or by welding (not shown).

A number of cutter and roller heads 228 and 230 respectively are slidably mounted upon each of the supporting rails 224, 226 and depend therefrom for engagement with the material 30'.

In this arrangement of the invention each of the roller heads 230 includes a roller 232 supported on channel bracket 234 and axle 236. A pair of clamp members 238 are mounted on front and rear upper surfaces of the channel 234' for engagement with beveled flange member 240 secured to thc'underside of I-beam 242 forming the balance of each supporting rail 224 or 226.-

Each cutting head 228, which includes in this example a double ended output shaft 244 of drive motor 245 and a pair of cutters 246, 248, is similarly mounted upon the beveled flange member 240 of the associated supporting rail 224 or 226 as better shown in FIG. 7A. To facilitate sliding the heavier cutting head along the associated supporting rail, the cutting head 228 is suspended from a pair of trucks 250 each having rollers 252 engaging the beveled surfaces of the flange plate 240. Each cutting head 228 can be affixed at any position along the associated supporting rail 224 or 226 by means ofclamp screw 254."

The aforementioned drive motor 245 and cutters 246, 248 are secured to the underside of pivoted mounting plate 256. The pivoted plate 256 includes a depending flange 258 so that the plate 256 desirably is pivoted about a point substantially on the same elevation as the motor output shaft 244. Vertical adjustment of the motor 245 and the cutters 246, 248 is effected by depth ofcut device 260.

The motor-mounting plate 256 desirably is point pivoted as better shown in FIG. 7B of the drawings so that the motor output shaft can be inclined slightly relative to the table top 218 and more importantly to the associated reference ridge 52' or equivalent structure. Inclination of the motor, motor shaft and cutters of each cutting head 228 can be adjusted by means of thumbscrews 262 and 264.

As also shown in FIG. 7B each of the cutters 246 or 248 is assembled on the adjacent end portion of motor shaft 244 by means of tubular spacers 266. To vary the spacing between the cutters 246, 248 (within the limitation imposed by the physical shape of the drive motor 245) of each cutting head 228ithe spacers 266 can be placed entirely on one side or the other of the, cutter 266 or differing lengths of spacers (not shown) can be substituted. This adjustment likewise is employed in the cutting apparatus 20 of FIG. 1.

With the use of a staggered array of cutter heads 228, as shown in FIG. 7, it will be apparent that very closely spaced or even overlapping grooves or other cuts can be made in the sheet or panel 30'. For example, the double groove arrangement 170-172 of FIGS. 6A and 68 can be provided without the use of a double-edge cutter (FIG. 18), by laterally shifting or staggering cutter head 228a the distance of one groove width relative to cutter 22%.

In the use of my novel cutting apparatus 210 it will be understood, of course, that the number of cutting heads 228 and roller heads 230 can be varied from that shown in the drawings. It will also be understood that one or more cutter blades 246, 248 can be removed from one or more of the cutter heads 228 or that unused cutter heads can be slid to a remote portion of the associated supporting rail, such as the cutting head 2286. It is also contemplated that one or more additional supporting rails and associated components, including an aligned reference ridge, can be provided.

One arrangement for automatically feeding sheet or panel material 30' through the cutting apparatus 210 is accomplished by provision of the combined feed and fence mechanisms 212, 214 mentioned previously. Each of the mechanisms 212 or 214 includes a fence blade 268 which in this example flushly engages the top surface 218 of the bench 216. In furtherance ofthis purpose each blade 268 is provided with a pair of transverse grooves to accommodate the reference ridges 52'. Of course, with certain forms of equivalent reference devices (such as shown in FIGS. 5A, 5B or 5C), the transverse grooves 270 can be omitted.

Each of the fence blades 268 is provided with an offset edge portion 272 the outer edge 273 of which is engageable with the adjacent edge of a sheet, board, or panel 30 for guidance purposes. The offset portion 272 also accommodates the adjacent run of feed chain 274 which engages sprockets 276, 278 in endless relation. Each chain 274 is provided with one or more projections 280, which in this example can be formed integrally with an associated one of the chain links. The projections 280 and associated link can be positioned, therefore, at any desired location along the length of the chain 274. The projections 280 desirably are laterally aligned with respect to the feed direction of material 30 and engage in this example the rear corners respectively of the material 30 for pushing the material through the cutting apparatus 210.

Each fence blade 268 can be adjustably clamped at each end thereof (by means of clamp plate 284 and thumbscrew 286) to the table 216 at any desired, aligned position therealong. Thus, the lateral distance between the fence blades 268 can be adjusted to accommodate any width of material 30' within the limitations imposed by the length of the table 216.

Irrespective of the adjusted, clamped positions of the fence blades 268 and the associated feed chains 274 mounted thereon, the front or drive sprockets 276 for the chains 274 (as viewed in FIG. 7) can be driven by unique driving means therefor provided in accordance with my invention. One arrangement of such driving means includes in this example a relatively short vertical stub shaft 288 secured at its upper end to the associated drive sprocket 276. The stub shaft 288 is rotatably mounted in a cantilevered end portion 290 of the associated fence blade 268. At the lower end of each stub shaft 288 is a worm gear 292 secured for rotation therewith. The worm gears 292 are enmeshed with leftand right-hand worms 294a and 294!) slidably mounted upon an elongated, splined input shaft 296 which desirably substantially coextends with the length of-the table or bench 216. The worms 294a, 294 I) drive the stub shafts 288 in opposite directions as denoted by arrows 295, 297. Although each worm 294a or 294!) is keyed to the splined shaft 296 for rotation therewith, the worm is easily slidable therealong and thus is carried along the spline shaft 296 when the associated fence assembly is adjusted along the table 216 upon loosening its clamping screws 286. Sliding of the worms 294 is caused by their engagement with the associated worm gears 292 and stub shaft 288, which are carried longitudinally of the table 216 when the fence and feed mechanisms 212, 214 are adjusted along the table surface 218.

Rotation of the spline shaft 296 in conventional bearing means 298 is effected by a suitable motor 300 and gear reduction unit 302, which can be mounted within the table structure 216. The bearing means 298 desirably are mounted closely to the vertical corners of the table 216 in order to allow a maximum range of adjusting movement of the fence and feed mechanisms 212, 214.

With reference now to FIGS. 8A through 8C other decorw live shapes are shown which likewise would present very difficult fabricating and assembly problems without the cutting apparatus provided by my invention.

For example, in FIG. 8A, a multifolded or louvered effect is presented by decorative shape 303. A blank or sheet member 30 is multigrooved to form outside and inside corners 306, 308 respectively. The sheet member 30' is folded inwardly and outwardly at adjacent pairs of grooves 306, 308 respectively. The walls of grooves 306 are clamped (not shown) and glued to form the mitered outside corners 306 of the shape 303. On the other hand, backing strips 310, for example of triangular cross section, are glued or cemented or otherwise secured to complete the mitered inside corners or joints 308. With this arrangement. the decorative member 303 can be substantially self-supporting, or alternatively, it can be secured to a backing member 311 depending upon the nature of the assembly in which the decorative shape 303 is utilized.

With conventional assembly practices, the decorative shape 312 of FIG. 88 would require at least 11 separately formed and joined pieces of material. The shape 312 however is formed from a single blank or sheet 314 which is grooved and cut as shown in FIG. SC. The outside 90 corners 316 of the shape 312 are formed by right angle or 90 grooves 318 imparted to the blank 314 as shown in FIG. 8C. On the other hand, the l35 corners 320 of FIG. 8B are formed by 45 grooves 322 made in the blank 314. Finally, the reentrant tubular joints denoted generally by reference characters 324 of FIG. 8B are completed by tongue-and-groove joints 326 (FIG. 88) by notching the lateral edges 328 of the blank 314 (FIG. 8C) and by the provision of grooves 330 inboard of the 90 grooves 318 in the material 314.

The blank 314 of FIG. 8C can be grooved and cut by suitably shaped cutters 246, 248 of the multiple cutter head machine 210 of FIGS. 7 and 7A. The grooves and other cuts in the blank 314 can be performed simultaneously by installing appropriate numbers of suitably shaped cutters in the cutting apparatus 210 or by passage of the blank 314 two or more times through the cutting apparatus 210. In the event that the grooves and other cuts of FIG. 8C are performed simultaneously it will be understood of course that additional cutting heads 228 can be installed and if necessary a third reference member such as the reference ridge 52' can be formed in the table or support 216 together with an additional supporting rail, cutting heads and roller heads mounted thereover. It will also be clear that when notching the edges 328 of the blank or sheet 314, that the outermost roller head 230 can be removed to permit bringing the cutting head 228 very close to the associated fence mechanism 212 or 214.

FIGS. 9 and 10 of the drawings illustrate cutting apparatus which is generally similar to that shown in FIG. 7 from the viewpoint that a pair of reference ridges 52 are utilized. Similarly, each of the ridges has one or more cutters 246' juxtaposed thereto.

In the instant arrangement, however, all of the cutters 246 are driven from a common drive means, for example electric motor 340 coupled to an input shaft 342 which coextends with the lengths of table 22 and reference ridges 52'. The shaft 342 is mounted in suitable bearing means on an upright 344 at each end of the table 22. In this example, the uprights are disposed intermediate the adjacent ends of reference ridges 52.

Each cutter 246 as better shown in FIG. 10 is rotatably mounted upon one or more bearing plates 346, the other end or ends of which are rotatively coupled to input shaft 342 through suitable bearings 348 to permit the shaft to rotate relative to the bearing plates 346. In this example the shaft 342 is provided with a spline 350 or other suitable keying means coextending therewith. A sheave 352 is secured to cutter spindle 354 for rotation therewith while an associated sheave 356 is slidably yet keyingly mounted on the input shaft 342. The inner races of the bearing plate bearings 348 are likewise slidably mounted upon the input shaft 342 so that the entire assemblage, including the associated cutter 246 can be slid along the length of the input shaft 342 whereby torque can be transferred from any point on the shaft 342 to the cutter spindle 354 by means of V-belt 357 or other suitable transmission. The shaft 342 is rotated by motor 340 which is coupled to an end portion of the shaft 342.

The bearing plate or plates 346 for each cutter 346' are connected through supporting bracket 358 and screw adjustment 360 to slide carriage 362. In this example the slide carriages 362 are slidably mounted upon a pair of supporting rails 364 secured between crossarms 366 ofthe supports 344. Each of the carriages 362 desirably is provided with a screw clamp 368 for rigidly securing the slide carriage 362 at any point along the length of the associated supporting rail 364. The screw adjustment 360 provides a vertical adjustment of the associated cutter plate 346 relative to the reference frame or ridge 52. When such adjustment is made the bearing plate or plates 346 pivot about the antifrictional connection with the spline input shaft 342.

It will be understood of course that the driving arrangement of FIGS. 9 and 10 can be utilized to advantage with the cutting apparatus as shown in FIG. 1. In the latter arrangement the supporting rail, slide carriage or carriages, cutting means 246' and associated components on one side of the support 344 can be omitted.

From the foregoing it will be apparent that novel and CITI- cient forms of Method and Apparatus for Making Cuts of Precise Depth have been disclosed herein. While I have shown and described certain presently preferred embodiments of the invention and have illustrated presently preferred methods of practicing the same, it is to be distinctly understood that the invention is not limited thereto but may be otherwise variously embodied and practiced within the scope of the following claims.

lclaim:

1. Cutting apparatus comprising a relatively rigid support, an elongated reference member formed on said support so that relatively thin material to he cut can be bent or bowed slightly on at least one side of said reference member to ensure contiguous contact therewith and therealong, cutting means juxtaposed above said reference member for cutting said material to a precise depth relative to said reference member, said reference member being so disposed that the weight of said material slightly bows or bends said material over said reference member and on at least one side thereof.

2. Cutting apparatus comprising a support, at least one elongated reference member formcd in said support and projected slightly from said support, means for urging material to be cut by said apparatus against said reference member and for bending said material slightly around at least one side of said reference member, and cutting means for said material juxtaposed to said reference member for cutting said material to a predetermined closely spaced distance from said reference member.

3. The combination according to claim 2 wherein said urging means include roller means juxtaposed to said reference member and engageable with said material to urge said material against and slightly around at least one side of said reference member.

4. The combination according to claim 3 wherein a pair of material feed mechanisms are mounted on said support, and means are provided for adjustably moving said mechanisms along said support.

5. The combination according to claim 4 wherein an input shaft is mounted for rotational movement adjacent said feed mechanisms, said shaft coextending substantially with the length of travel of said mechanisms, a gearing train is provided for each of said feed mechanisms and having an element slidably and keyingly mounted on said input shaft for rotation therewith, each of said gearing trains having a second element operatively coupled to said feed mechanisms respectively, said first-mentioned slidable elements being carried along said input shaft by movement of said feed mechanisms, and said means are provided for rotating said input shaft.

6. The combination according to claim 2 wherein said urging means and said cutting means include adjacent relatively closely spaced resilient roller and rotary blade respectively.

7. The combination according to claim 2 wherein said apparatus includes a supporting rail mounted in generally parallel-spaced relation relative to said reference member, and said cutting means and said urging means are slidably mounted on said rail.

8. The combination according to claim 7 wherein a plurality of said cutting means and said urging means are slidably mounted upon said supporting rail.

9. The combination according to claim 2 wherein said cutting means includes a double-ended spindle, and a rotary cutter is mounted adjacent each end of said spindle, said spindle is extended generally parallel to said reference member but is pivoted transversely thereof for adjustable inclination relative thereto.

10. The combination according to claim 9 wherein'said spindle is adouble-ended output shaft of an electric motor forming part of said cutting means.

I]. The combination according to claim 9 wherein means are provided for adjustably mounting said cutters along the adjacent end portions of said spindle to vary the spacing between said cutters.

12. The combination according to claim 2 wherein a plurality of said cutting means and said urging means are juxtaposed to said reference member.

13. The combination according to claim 2 wherein a second reference member is similarly formed in said support and extends generally parallel to said first-mentioned reference member, additional cutting means and urging means are juxtaposed to said second reference member, and said additional cutting means are capable of staggered adjustment relative to the first-mentioned cutting means for making closely spaced or overlapping cuts in said material.

14. The combination according to claim 13 wherein a second reference member is similarly formed in said support and extends generally parallel to said first-mentioned reference member, a second supporting rail is mounted in a generally spaced and parallel arrangement relative to said second reference member, and additional means and urging means are slidably mounted upon said second supporting rail.

15. The combination according to claim 2 wherein said reference member is a relatively narrow ridge formed in said support and projecting above the surface thereof.

16. The combination according to claim 15 wherein said urging mean's include a resilient roller engageable with said material, the footprint area of said roller when so engaged being substantially wider than the width of said reference ridge.

17. The combination according to claim 2 wherein said reference member is formed by intersecting plane surfaces of said support, the intersection of said surfaces being at an angle slightly less than l8().

18. The combination according to claim 2 wherein said reference member is a stepped surface portion of said support.

19. The combination according to claim 2 wherein said reference member is coplanar with the major proportion of said support but is formed by relatively wide shallow groove means in a surface of said support and adjacent said reference member.

20. The combination according to claim 2 wherein said reference member is a nonresilient roller rigidly but rotatably mounted in a depression in said support. said roller projecting slightly above the surrounding surface area of said support.

21. The combination according to claim 20 wherein a rigid backup member slidably engages said roller for cleaning and supporting purposes.

22. The combination according to claim 2 wherein said urging means include a resilient roller engageable with said material, the footprint area of said roller extending a substantial distance transversely of said reference member to urge said material against said reference member and slightly around at least one side thereof.

23. The combination according to claim 2 wherein a pair of fence mechanisms are spacedly mounted on said support, and means are provided for adjustably moving said mechanisms along said support and said reference member.

24. The combination according to claim 23 wherein material feed means are mounted on each of said fence mechanisms for feeding said material through said apparatus.

25. The combination according to claim 2 wherein said reference member includes a leading edge spaced above the surrounding surface of said table, said edge closely engaging said material for the removal of foreign matter therefrom, an exhaust duct is extended through said support and communicates with the space between said material and said support when said material is placed thereon at an area adjacent said leading edge for removal of said foreign matter from said space.

26. The combination according to claim 2 wherein rigid and spring-loaded fences are provided on said support for engagement with said material during passage through said apparatus, and cut spreader means are mounted on said apparatus and are extended transversely of said reference member so as to be generally parallel to the direction of material through said apparatus, said spreader means being engageable with a cut in said material made during a previous pass through said apparatus to prevent collapse of said cut.

27. The combination according to claim 2 wherein said cutting means includes at least one rotary blade, means for rotating said blade such that that portion of said blade engaging said material has a motion component in the direction of travel of said material through said apparatus so that said blade when engaging said material urges said material against said reference member.

28. Cutting apparatus comprising a rigid support, at least one elongated reference means formed in said support, means for urging a finished surface of material to be cut by said apparatus flushly against said reference means for substantially contiguous contact therewith and therealong, and cutting means for said material juxtaposed to said reference means and disposed. adjacent said urging means for cutting said material to a predetermined closely spaced distance from said reference means, said reference means extending transversely of a cutting path of said cutting means.

29. The combination according to claim 28 wherein said reference means include a perforated section of said support extending transversely of the direction of movement of said material, and means are provided for applying a partial vacuum to said perforated section.

30. The combination according to claim 29 wherein said partial vacuum means are adjustably coextensive with the width of said material.

31. The combination according to claim 28 wherein said cutting means include at least one cutting blade juxtaposed to said reference means, and means are provided for rotating said cutting blade at any preselected position along the length of said reference means, said rotating means including a shaft having keying means coextending substantially therewith, said shaft substantially coextending with said reference means, means for mounting said cutter blade for movement along said reference means, and a transmission mechanism coupled to said blade forrotation therewith, a said mechanism slidably and keyingly engaging said input shaft for movement therealong with said cutter blade.

32. Cutting apparatus comprising a rigid support. at least one elongated reference member formed in said support, means for urging a finished surface of material to be cut by said apparatus flushly against said reference member, and cutting means for said material to a predetermined closely spaced distance from said reference member, said reference member including a ridge projecting above the surface of said support, said ridge having an arcuate contour extending along its length such that said ridge is higher adjacent its midpoint than adjacent its ends relative to said support.

33. The combination according to claim 32 wherein holddown means are provided adjacent each end of said ridge for engaging said material to bend said material longitudinally of said ridge into flush engagement along said ridge.

34. The combination according to claim 33 wherein said holddown means are disposed also for bending said material transversely of said ridge.

35. A method for making cuts of precise depth, said method comprising the steps of establishing an elongated frame of reference extending transversely of an intended cut in said material, urging one side of material to be cut into flush engagement with said reference frame, bending said material over said frame in a direction substantially parallel to said cut and along a length of said frame and cutting the other side of said material to a depth disposed at a precisely predetermined distance from said reference frame.

36. The method according to claim 35 including the additional steps of establishing said reference frame with an elongated slight arcuate contour, and bending said material longitudinally as well as transversely of said contour to ensure said flush engagement.

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