US2663332A - Veneer sheet patching machine - Google Patents

Description

1953 R. v. PETERSON 2,663,332

VENEER SHEET PATCHING MACHINE Filed Dec. 26. 1950 4 Sheets-Sheet l Ennentor ROY .v. PETERSON Z M (Ittornegs 22, 1953 R. V. PETERSON 2,663,332

VENEER SHEET PATCHING MACHINE Filed Dec. 26, 1950 4 Sheets-Sheet 2 ROY V. PETERSON :mventor (Ittomegs Dec. 22, 1953 R. v. PETERSON I 2,663,332

VENEER SHEET PATCHING MACHINE Filed Dec 26, 1950 4 Sheets-Sheet s FlG .9

ROY V. PETERSON 3nventor (Ittomegs Dec. 22, 1953 R.-V. PETERSON VENEER SHEET PATCHING MACHINE 4 Sheets-Sheet 4 Filed Dec. 26, 1950 Smaentor attorneys FIG' ROY v. PETERSON Patented Dec. 22, 1953 UNITED STATES PATENT OFFICE VENEER SHEET PATCHIN G MACHINE Roy V. Peterson, Tacoma, Wash.

Application December 26, 1950, Serial No. 202,603

- Claims.

This present invention relates to a venee patching machine which is characterized by construction wherein a rotary cutter is mounted for verticalmovement and the cutter head has pivoted cutters capable of cutting a patch hole in a sheet of veneer and then passing up through the veneer to cut a patch from a veneer strip that will fit'the hole. Means are then providedfor seating the patch in the hole previously cut all in a single sequential operation.

The unprecedented demand for plywood is gradually exhausting the supplylof choice peeler logs and forcing the manufacturers to resort to the use of. logs that-are not choice from which they peel the veneer and produce a veneer sheet having blemishes therein. These conditions in turn call for-some means to expedite the patching of defective portions of the veneer and do it in a manner which renders the veneer fully acceptable for its intended purpose. j v

Even in this mechanical age a very large proportion ofthe patching of the veneer is still a tedious hand-operation where a workman with a'die and mallet cuts out the defective portions and then cuts a patch to fit this'portion. This is on one hand a very tedious and expensive operation and on the other hand it does not produce a tight joint along themargin of the patch so that the resulting plywood is not acceptable for many uses. A number of attempts have been made in the past to produce machines for the patching of plywood. Most of these machineshowever use pre-cut patches or they stamp out the defective material from the veneer sheet in their operations. Such patching can only by accident produce a perfect joint and their general use has resulted to a large degree inthe downgrading of the finished product.

In this present machine a sequential series of operations is performed in which a hole of a proper bevel is cut, then a patch'is out which will accurately fit into this hole and lastly the patch is seated in the pre-cut hole in such a manner that the grain direction is under control and can be made to match the'original grain.

The principal object of this present invention is to provide a machine whichlwill achieve a series of sequential operations which will form a perfect, patch in a plywood sheet;

A further object of this invention is to provide a veneer'sheet patching machine in which the hole including the defective'po'rtion of the sheet is cut out with a high speed revolving cutter and this same cutter, using the oppositeedges of the cutter propencuts a'patch by the same method to fit accurately the hole (out in the veneer sheet.

A further object of this invention is to provide a plywood patching machine in which a rotary cutter having a plurality of pivoted cutting mem-' bers so arranged that the outer margins of the cutter will cut the hole in the damaged piece oi' veneer stock. By progressing upwardly the inside margins of the cutter element will cut the patch to fit the hole previously cut in the sheet.

A further object is to provide an improved method of patching veneer in which a faulty area of the veneer is removed, an identically shaped patch is cut, and the patch is positioned in the veneer in one sequence of operation, providing in the process that the patch is accurately oriented above opening and that the grain of the patch runs in the same direction as the grain in the vener.

Further objects, advantages and capabilities will be apparent from the description and disclosure in the drawings, or may be comprehended or are inherent in the device.

In the drawings: 7

Figure l is a perspective view of a specific embodiment of my veneer'sheet patching machine;

Figure 2 is in perspective, on enlarged scale and in fragmentary form, viewing operating members below the table top;

Figure 3 is a perspective view, on enlarged scale, of the cutter head;

Figure 4 is a top view of the cutter head;

Figure 5 is a view, partly in section, taken on line 5--5 of Figure 4; V

Figure 6 is a schematic top view of a portion of the cutter head with the cutters in retracted position;

Figure 7 is similar to Figures with the cutters in expanded position Figure 8 is a view of operating members partly in vertical cross-section and with the cutter head sectioned as indicated by line 8-8 of Figure 4;,

Figure 9 is a view of part of the operating members as shown in Figure 8 and in their next position in the sequence of operation;

Figure 10 is similar to Figure 9 with the O el ating members in their next position in the sequence of operation;

Figure 11 shows the position of the operating,

the drawings, the numeral 20 designates generally the frame of this machine. This may be variously constructed, however, due to the requirement of strength and weight, it can be very properly formed as a large casting or welded together of heavy plate stock. The frame consists essentially of the base portion 25, and upright support pillar 22 and a table 24. Table 24 should have considerable extent so that a defective portion of plywood can be processed even'when it is near one margin of the sheet without the necessity of turning the sheet around. To this end, table 24 is provided with the extension portion 25. This calls for the provision of an overhanging arm or support portion 26, and as this unit must support the spreading effect of the patch feeding ram, it must be generously proportioned so as to have the requisite strength for its function. To this end it has been found convenient to provide a wide heavy rib as 21 extending entirely around the head of the veneer-receiving opening 28. Fixedly secured to the end face of arm 28 is the ram air cylinder 38 within which 'ishoused the patch seating ram 3!. Also secured to the end face of arm 26 are the similar veneer strip holding brackets 32. Adapted to coact with the lower bar portion of bracket 32 are the presser bars 33. These bars aremovable and under control of spaced pistons 34 which are in turn supplied by the fiuid line 35. Pressure bars 53 are preferably cross-connected so that a pressure ring 31 can be secured to the same pistons -34 and be actuated by them in order to provide means for backing upthe veneer that is being-patched when the rotary cutters are fed up from beneath them.

In order to provide asimilar backing for the veneer sheet when the patch is being seated therein by rams 3!, some means must be provided which can be removed from the path of the cutter during the cutting operation and then be moved so as to back up the plywood and support it especially near the margins of thecut out opening because any opening'in table 24 capable of passing the cutter upward through-it will be considerably larger than the hole cut in the plywood by the cutters.

One satisfactory solution'to this problem is to employ an oscillating plate -40 which has fixedly secured to it at its center the downwardly extending shaft M, which passes through table 24 and in turn has securedto it an'arm 42 which can be actuated by any convenient .means. One such means isshown as the fluid cylinder 43 having a piston 44 which is capableofgivingthe required oscillation to plate 40 so that it may take the alternate positions shown in Figures 13 and 14. Suitable slotting is essential inith'erend of piston 44 which engages pin 45 so :thata free swing can beachieved without :binding.

In order to achieve accuracy in cutting the hole in the veneer sheet containing the defect and to cut the patch to fit thesame it has been found desirable to employ a special form of cutter-head. My cutter head is probably-best illustrated in Figures 3 through 7 in whichacutter-base is employed. This base is in the form generally of a sleeve having the interior bore 5| and a threaded lower portion of the same 52 which provides the mounting for the cutter on a vertically movable, power driven holder.

These members are pivoted ason bolts or cap screws 56. On their heavier end, cuttersfit and 55 are each provided with a pluralityof-cutting devices or blades as 58 and 59.

ting blades "on each cutter.

It is to be noted that these cutters are provided with properly shaped cutting edges 68 for cut ting accurately to size a piece of wood contained within the circle described by the cutters. This edge is used for cutting the patches from strip stock made normally of the same thickness veneer as the veneer sheet. Juxtapositioned with the edges are the cutting edges 62. These are oppositely directed so that they will produce an accurate cut on the outside of the circle described by the cutters. These are used to cut the hole required by the patching operations in the veneer. Attention is directed to the fact that a U shaped opening is provided between the two sets of cut- This makes it possible to properly dress the cutting edges 52 and gives clearance for waste that might otherwise tendto lodge against the cutter blades.

The lighter weight ends of cutters 5d and 55 are each provided with an adjusting screw 85 positioned in suitable outstanding bosses. These screws abut the :stop pins and provide an accurate limit for the rotary or pivoted motions of the cutters when the same are fully extended by centrifugal force when they are cutting through the veneer patch. A limit stop is also provided by the downwardly extending lugs Q8 and-69 which are suitably engaged on their inner surfaces by devices to 'be later described. Both of the lugs68 and 69, one on each of the cutters, is provided with a beveled cam space 76.

The cutter assembly ismounted for use on a hollow arboror holder 13, attached to the same by having exterior threads on the upper end of holder 13 adapted to engage threads 52 of the cutter assembly, the cutter head being designed to operate in one direction of rotation only. The holder is slidably mounted upon the tubular power shaft 14 which is journaled upon suitable bearings 15 which in turn are appropriately supported in bearing housings 16 secured to the supporting wall 22 of the main frame.

Any proper form of drive may be provided for the drive shaft 14, as for instance, the electric motor 11 mounted upon wall 22 and-connected as by a plurality of V belts 18 to a multiple sheave '19 which is fixedly secured to shaft 74. The holder 13 is provided with a key 8! adapted to slide in keyway 82 of the hollow shaft M and thus provide'rotation for the cutter head assembly.

A positioning plate 84, *for moving holder '53 vertically, encircles shaft HI-and houses an antifrictionbearing 85 provided so as'to prevent any frictional load on plate '84 due tothe weight of holder I3 and the :cutter assemblyfll. As it is necessary that the cutter be raised and lowered in timed sequence, a ,pushrod .86 is provided which is controlled by the cam member 88 which may be rotated by any suitable means. .An adjustable stop 89 is provided to limit the upward travel of plate 84 andpreventinterference between the cutter elements and the .pressure ram 3!.

Apatch holding rod 90 is providedfor holding the cut patch in its proper position with respect to ram 3|. This rod, to avoid interferences,

. passes through the axis of the'hollow shaft '14 and may be controlled. in .an upward ositioning by any convenient means. However inasmuch as. a constant pressure. isdesired during its operational cycle a fluid cylinderand piston assembly as 92 appears to be the-preferredstructure. The

operation of the moving -.means for rod "941 a must be so timed as to function at its proper point in the patching cycle.

Methods of operation In using this present machine for the patching of defective plywood veneer or veneer sheets, the sheet is placed upon table 24 and as much of it as necessary can be extended into the slot or opening 28. The defect or blemish in the veneer is then placed under ram 3|. This places it over an opening I in table 24 and in this stage of the cycle, backing disc 40 is in the position shown in Figure 14 with the opening I02 aligned with opening I00. A strip of veneer of sufiicient width to make it possible to cut the required size patches is placed on bars. 32 and under the movable bars 33. The first functional operation isthat of the moving of cylinders 34 which move downwardly thus supporting the perimeter of the projected hole in the veneer sheet under ring 3'! and at the same time the strip stock is held between bars 32 and 33. The next operation in sequence is for the revolving cutter assembly 5 to be moved upwardly through hole I00 by means of the actuation of push rod 86 raising plate 84. This step is illustrated in Figure 8. The cutter assembly then moves upwardly after the showing of Figure 9 and the waste patch W is out from the veneer sheet V. This circle of veneer is waste and can be disposed of in any convenient manner. The most generally useful arrangement is an air blast which blows the waste circle out of the machine and directs it to a suitable hopper for disposal. As the cycle continues, the condition of Figure 10 is reached, where the cutting members 54 and 55 have moved up high enough so that boss members 68 and 69 no longer lie on shaft 14, and due to the fact that the cutters themselves are arranged with the heaviest portion of the same at the end carrying the cutting blades, centrifugal force acting on the revolving unit throws the cutting element upwardly and this position is shown in Figure 10.

Figure 11 is the next step in the operation and patch P has been cut from the strip veneer S. In this operation a different set of cutting edges has been used to produce the patch. In this instance the cutting edges 80 of the cutters have been used whereas tocut the hole in the veneer the rearwardly disposed cutting edges 62 were employed. This is required in order that the hole on one hand has its surface cut by a cutting edge that is most favorably ground to give a good clean surface and likewise the patch P is also cut by a plurality of cutters which are ground to give a most perfect cut on the outside of the disc. It is in this manner that the perfect junction can be had between the patch and the veneer that is being prepared. As the patch P is being cut the holding rod 90 has been actuated by pressure means 92 and is extended upwardly to hold the patch in firm contact with the bottom of ram 3|.

During the period covered by this foregoing operational step, disc 49 has been shown in the position in Figure 14 in which opening IE2 is aligned with opening iiiii in table it. However as soon as the cutters are retracted downwardly, cam surfaces it of the cutter lugs 88 and 69 again contact the tapered ends I94 of shaft hi and this forces the cutting elements back to their smallest diameter so that they can be withdrawn through the hole already produced in the plywood sheet even though during the process of 6 cutting the patch the cutters were extended beyond the diameter of that hole. The next operation is that shown in Figure 13 in which plate 4!! is partially revolved so that except for the narrow slotted portion I06 necessary to permit the push rod to remain in contact with the patch P, the disc and table 24 now fully supporting the margins of the plywood around the hole cut. The next operation is for the ram 3| to move downwardly and this explains the desirability of using a fluid cylinder assembly as 92 in that a constant pressure canbe maintained on the patch by rod 95 yet this can be overcome by the large diameter of ram 3I. The continuation of this opera tion fully seats the patch in the veneer stock. If desired, glue can be applied by means well known in the trade. However, normally, if the patch is snapped into place much like the seating of a plastic crystal in a wrist watch, a very tight engagement is had without the need of gluing and then, when the veneer is made up into final stock, the gluing between the various plys is adequate to hold the unit in place. The final operation is the retraction of rod at and ram 3i and to release pressure on ring 31 and bars 33 so both the veneer sheet andthe veneer strip can be moved to a new position, disc 4 positions itself after the showing of Figure 14 and the device is ready to start a new cycle.

It is believed that it will be clearly apparent from the above description and the disclosure in the drawings that the invention comprehends a novel construction of a veneer sheet patching machine. 7

Having thus disclosed the invention, I claim:

1. A veneer patching machine, comprising: a horizontal table having an access opening therein; a vertically movable ram positioned above said access opening; a supporting bracket for a patching sheet positioned below said ram and. above said table; means for clamping such patching sheet on said bracket; means for clamping a veneer sheet on said tableabove said access opening; a vertical power shaft having its upper end positioned near said access opening and un der said ram; a cutter head movable longitudinally of and connected to rotate with said shaft; means for moving said cutter head vertically; means for rotating said power shaft; a patch holding rod journaled in said power shaft; means for moving said rod vertically; and a plurality of cutters pivotally mounted on the upper portion of said cutter head at points evenly spaced from the axis of rotation of said power shaft, each cutter having a heavy end on one side of its pivot of such weight that said heavy end will tend to swing outward when said cutter head is rotated, stop means limiting the outward movement of said heavy end, coacting cam means between each cutter and said power shaft holding said heavy end in a retracted position when said cutter head is in a lower position, and two cutting edges on said heavy end of each cutter, one of said cutting edges being disposed to cut inside of the other of said cutting edges, the outside cutting edge being for cutting a patching opening in such veneer sheet and the inside cutting edge being for cutting a patch from such patching sheet of the same size as said patching opening.

2. A veneer patching machine, comprising: a horizontal table having an access opening therein; an oscillating plate mounted in said table having in a first position a plate opening aligned with said access opening and having in a second position a narrow slot aligned with, said access opening and connecting with said plate opening; vertically movable ram means: positioned above said access opening; means for supporting and securing a patching sheet between said ram means and said access. opening; a vertical patch holding rod positioned below said ram and vertically movable to want with said ram and of a size to fit said slot and aligned therewith when said oscillating plate is in said second position; means for clamping a veneer sheet on said table above said oscillating plate; a cutter head; means for moving said cutter head vertically upward through said access opening to. contact said veneer sheet and said patching sheet; cutters on said cutter head; means positioning said outters to out in such veneer sheet a patching opening, in a lower position, and to cut from said patching sheet a patch of the identical size of said patching opening, in an upper position said cutters being positioned more widely spaced apart in said upper position than in said lower position; and means for oscillating said oscillating plate to move to said second position as said ram means descends to position said patch in said patching opening and for oscillating said oscillating plate to move to said first position as said cutter head moves upwardly.

3. A veneer patching machine, comprising: a table having an access opening therein; a ram having its longitudinal axis normal to the plane of said table and aligned with said access opening, said ram being movable toward and away from said access opening; a supporting bracket for a patching sheet positioned between said rain and said table; means for clamping such patching sheet to said bracket; means for clamping a veneer sheet to said table between said access opening and said supporting bracket; a power shaft having one end positioned near said access opening on the opposite side from said ram and having its longitudinal axis normal to the plane of said table; a cutter head positioned on said shaft and connected to rotate with said power shaft; means for moving said cutter head toward and away from said ram; means for rotating said power shaft; cutters on said cutter head and evenly spaced from the axis of rotation of said power shaft; and means positioning said cutters in a first position so that a patching opening is out in such veneer sheet as said cutters contact said veneer sheet and in a second position more widely Spaced apart than in said first position so that a patch is cut from such patch ng; sheet, as said cutters contact such patching sheet, of they same size as said patching opening.

4. In a veneer patching machine, a cutter assembly, comprising: a power shaft having on one end a tapered cam surface; a cutter head mounted on said power shaft to rotate therewith and slidable longitudinally of said power shaft; cutter means pivotally mounted on said cutter head having a heavy end on one side of its pivot wherebysaid heavy end will tend to swing outward when said cutter head is rotated and having a light end on the other side of said pivot, said light end having a cam portion directed toward said tapered cam surface to coact therewith, on contact therebetween, to move said heavy end inward, stop means limiting outward movement of said heavy end, and cutting edges mounted on said heavy end to cut a patching opening when said heavy end is in an inward position and to cut a patch when said heavy end is in an outward position.

5. In a veneer patching machine, a cutting assembly, comprising: a cutter head having on one end and evenly spaced from the center of said cutter head a plurality of pivots; a cutter mounted on each of said pivots, said cutter having a heavy end on one side of its pivot whereby said heavy end will tend to swing outward when said cutter head is rotated, means for pivoting said heavy end inward, stop means for limiting outward movement of saidheavy end, and two cutting edges on said heavy end, one of said cutting edges being disposed, when said heavy end is in its inwardposition, to cut a patching opening of the same size as the patch which the other cutting edge is positioned to cut when said heavy end is in an outward position.

ROY V. PETERSON.

References Cited in the file of this patent UNITED STATES PATENTS Number

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