US2737214A - Machine for producing sheets of indefinite length composed of slitted wood veneer and a flexible backing - Google Patents

Description

March 6, 1956 A; ELMENDORF 2,737,214

MACHINE FOR PRODUCING SHEETS OF INDEFINITE LENGTH COMPOSED OF SLITTED WOOD VENEER AND A FLEXIBLE BACKING Original Filed March 14, 1947 3 Sheets-Sheet l Inz/anfor.

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March 6, 1956 A. ELMENDORF 2,737,214

MACHINE FOR PRODUCING SHEETS OF INDEFINITE LENGTH COMPOSED OF SLITTED WOOD VENEER AND A FLEXIBLE BACKING Original Filed March 14, 1947 3 Sheets-Sheet 2 llulllll-lllllllllllllll. ll l l hnflnl l hfll I I l l l I I l l l l I l l I I I l I l 1 I I l l| A. ELMENDORF fill- Ifl//zar. MM;

E FOR PRODUCING SHEETS OF INDEFIN OF SLITTED WOOD VENEER AND A FLEXIBLE BA u A 9 AQ M m 0 v Xv N E K n m M o N m t. U f i Q N 3 1 5 I- 1956 MACHIN Original Filed March 14, 1947 March 6,

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United States Patent 9 MACHINE FOR PRODUCING SHEETS OF INDEFI- NlTE LENGTH COMPOSED F SLITTED WOOD VENEER AND A FLEXIBLE BACKING Armin Elmendorf, Winnetka, Ill.

Original application March 14, M47, Serial No. 734,695. Divided and this application August 18, 1952, Sena] N0.304,922

4 Claims. (Cl. 144-2) The present application is a division of my now abandoned application having the same title, Ser. No. 734,695, filed March 14, 1947.

Thick wood veneer that has a flexible backing, such as paper for example, has many uses, particularly in the building field. Because veneers are thin compared with lumber commonly employed, much less wood is required to cover a given area with the composite material than with ordinary lumber; thereby achieving not only a saving in cost, but also compensating for shortages in lumber. It is not enough that the veneer be bonded to a backing, but it must not warp, and provision must be made for shrinkage and expansion.

Panels made of wood veneer having a thickness of about three sixteenths of an inch, backed with tough paper, have been found to be satisfactory when the veneer is partially divided, by slitting, into narrow strips, normally about one half inch wide, with the division lines running in the general direction of the wood grain; space for expansion being obtained when the slits are widened to spread the strips apart from each other, about ten to thirty thousandths of an inch for strips one half inch wide.

The primary object of the present invention is to make possible the manufacture at a relatively high speed of a continuous sheet of thick wood veneer expanded, by slitting; particularly where the veneer is backed with heavy paper or other flexible material, to make it suitable structurally for wall panelling.

The various features of novelty whereby the present invention is characterized will hereinafter be pointed out with particularity in the claims, but, for a full understanding of the invention and of its objects and advantages, reference may be had to the following detailed description taken in connectionwith the accompanying drawings, wherein:

Figure 1 is a top plan view of those portions of a machine, embodying the present invention.

Fig. 2 is a side elevational view of that part of the machine appearing in Fig. 1.

Fig. 3 is a vertical, longitudinal section view showing, on a somewhat larger scale, somewhat less of the machine than appears in Fig. 1.

Fig. 4 is a vertical, longitudinal section on a still larger scale, showing a portion of one of the press-closing mechanisms.

Fig. 5 is a vertical, longitudinal section, showing the upper part of the machine at the slitting mechanism, the cutter being in its raised position.

Fig. 6 is a view similar to Fig. 5, showing a smaller part of the machine, and the cutting blade being down.

Fig. 7 is a vertical section, on a much larger scale, through the cutting blade and its immediate support.

In carrying out my invention, I feed a sheet of wood veneer that may have a width as great as eight feet and a thickness of about three sixteenths of an inch, with the wood grain running crosswise, through the slitting mech- "ice anism. There the sheet is slit crosswise into narrow strips, say about one half inch wide held together, edge to edge, by uncut strands; preferably by means of a long blade that chops into the wood across the entire width of the sheet. The blade may be so shaped that it pushes each strip, as it is cut, ahead a little faster than the speed of the unslit part of the sheet. In other words, the sheet is expanded lengthwise, namely across the grain of the wood. After the slitting point has been passed, a flexible backing sheet, preferably heavy, tough paper, coated with adhesive, is brought against the under side of the veneer and is bonded thereto in a second hot press. The resultant continuous sheet may be rolled up, as it is finished, into rolls as large as can conveniently be handled, or it may be cut into short lengths.

In the drawings, 1 represents a long, low frame that may conveniently be composed of structural steel beams, the only requirement, aside from rigidity and ruggedness, being that there be a long wide bed.

The sheet of veneer B to be operated upon is inserted between lower and upper sets, 5 and 6 of stationary, longitudinal rails mounted on the bed. At the entrance to the space between the two sets of rails are two transverse shafts 32 and 34, one above and the other below the plane in which the veneer sheet lies. On the upper of these shafts are a series of cushioned clamping rollers 35 located directly above the corresponding unyielding rollers 36 on the lower shaft. The veneer sheet is gripped between these two sets of rollers, which, properly driven, act as feed rollers.

Slitting of the veneer sheet is accomplished while the latter is moving ahead between rails 5 and 6. The frame of the machine is provided with two sturdy columns or uprights 37, one at each side, between the ends of this rail-filled area; the rails being interrupted at a transverse line that interesects these uprights. A blade 38 extends across the machine, above the rails, in registration with the interruptions or excisions in the latter; the blade standing on edge and having a sharp cutting edge on the under side. This part of the machine is best shown in Figs. 5 and 6 of the drawings. There is a transverse shaft 3? extending between and having bearings in the uprights 37, toward the upper ends of the latter. Fixed to this shaft are two eccentrics 40, lying between the uprights and spaced apart from each other. On each eccentric is a strap 41 that has a long depending stem or arm 42. The members 42 are connected together, between their ends, by a wide, flat bar 44; and the blade is in turn fastened to this bar so as to project down below the lower edge of the same. When shaft 39 is rotated the blade is raised and lowered once during each' revolution. The parts are so proportioned that when the blade moves down it cuts a slit b into, and entirely through if desired, the veneer sheet; the upward movement of the blade being sufficient to allow ample clearance with respect to the sheet. In the machine illustrated, as best shown in Fig. 6 wherein the slitting blade is at the lower limit of its vertical movements, the blade cuts only partly through the veneer; but, in doing so, its progressively thickening blade stresses the remaining uncut web in the continuation of the median plane of the blade beyond the rupture point. But, be cause the wood grain is never entirely parallel to the edge of the blade, there is never a complete tear and a clean separation of the wood across the width of the sheet, as uncut fibers crossing said plane remain intact and tie the strips together. The slitted veneer is somewhat like that illustrated in my Patent 2,018,712, wherein the gaps are much wider, however. Therefore, in the present machine the strips remain connected together and to the main veneer body, being simply pushed forward a little, one at a time, by the blade and then moving ahead with the rest of the strips as another strip is created. When the blade is caused to cut clear through the veneer there is still a lengthening of the product due to fuzz left on the meeting edges. Inthe gap in the rails, in such position that the veneer sheet lies on top of and in contact therewith, is an anvil in the form of an idle, rotatable roller 45 of metal or other hard material, for cooperation with the blade.

It is desirable that the blade travel along with the veneer sheet while engaged therewith. To accomplish this I cause the blade to swing through a small angle While' moving up and down; there being near each eccentric strap arm a vertical lever 45 pivoted near its lower end, as at 47, to a bracket 48 fixed to the adjacent upright 37; and the lower end of this lever being connected to the lower end of the corresponding eccentric strap arm, while the upper end is connected by a link 5!? to the strap itself.

As soon as the veneer is slit it is ready to receive a backing. in the arrangement shown, the rails 5 are cut away a little beyond the excisions for the accommodation of the roller anvil .6, to allow an idle roller 51 to engage a sheet resting on such rails; this roller extending across the machine from one side to the other. A roll of paper P may be mounted under the bed of the machine, as best shown in Fig. 2; an end of the paper being drawn through a glue-applying apparatus 52 and then being carried up and over roller 51 and its glue coated side engaged with the underside of the slitted sheet.

Effective bonding of the backing with the veneer is assured by providing a laminatin press 54, to place the composite sheet under the proper bonding conditions during periods when the feedin. of the work is interrupted. The press, comprising an upper plate 55 and a lower plate 56, is placed only a little way beyond roller 51 over which the paper is brought into contact with the veneer.

Upon leaving the laminating press the composite sheet may be gripped between upper and lower feed rollers 57 and 58, mounted on transverse shafts 59 and 60 at the discharge end of the machine. These rollers feed the stock from 2% to 6% faster than the rate of feed before slitting, to compensate for the expansion due to slitting.

A suitable blade 61 may be provided to sever the composite sheet C after it leaves the feed rollers 58 and 57. If desired, the composite sheet may be rolled up automatically as it emerges from the machine; a pair of parallel, transverse rollers 62 and 6 being placed beyond such feed rollers and one of them being driven so that, after a small roll has been created, it may be laid in the cradle formed by rollers 62 and 64 and be automatically turned thereafter.

The foregoing description of the machine has been confined to the more basic features of construction, leaving the driving mechanism and certain structural details yet to be described.

Any suitable press may be employed. in the arrangement shown there are four posts 65 outwardly from the plates of the press, one near each corner. Heavy transverse beams 66 extend between the upper ends of the posts, each connecting one post to the corresponding post on the opposite side of the machine. At the base of the frame are two other beams, 67, parallel to and directly below beams 66. Each of these posts is round and is externally screwthreaded; the screw threads being of any desired type. Each post extends loosely through both an upper and a lower beam. The upper beams are fastened to the upper plate or platen. Underneath the lower plate or platen, and fastened thereto, are two light beams 69 each located in a common plane with one of the beams 66 and the corresponding beam 67. Each beam 69 has flanges '76 projecting therefrom, one at each end; the posts extending loosely through these flanges. On the posts are nuts 71 for adjusting the separate parts of the press that move relatively to each other in the vertical direction.

The lower plate of the press may be moved up and be pressed strongly against the work by a pneumatic power device. As best shown in Fig. 4, each beam 67 has on top of the same a pair of brackets '73, one near each side of the machine. A shaft *79 extends through and is journalled in the brackets on each beam. Fixed to these shafts are eccentrics 8i). Cooperating with each eccentric is a strap 81 in the form of a link that connects an ear 32 on the underside of the corresponding beam 69 to the eccentric. Shafts 79 have fixed radial arms 84 extending in the upward direction. Positioned between each arm 84 and the corresponding arm directly opposite the same is a horizontal pneumatic cylinder 85 that contains two pistons 56, each of which is provided with a piston rod 87 connected to one of the radial arms 84, by a link 88. Air or other fluid may be admitted into the cylinder through a pipe 89 that contains a valve N) to permit fluid to be supplied to and exhausted from the cylinder. in the positions of the parts shown in full lines in Fig. 4, the press is open, the lower plate being down. When the actuating cylinder is energized, the beams 6% are raised and the press is closed. The valve may be turned to the press-closing position by an electromagnet 91. A spring 92 may be provided to return each piston to the position shown, when the pressure is released.

The machine may be driven from any suitable source of power; two motors being used in the particular arrangement shown. Thus, motor 94 drives the feeding mechanism and motor 95 drives the slitting blade.

The drive for the slitting blade is simple. Motor 95 is mounted on top of the framing for the slitting apparatus and drive shaft 39 of the latter through a sprocket chain transmission 96; a clutch 97 being interposed between the motor and said shaft so that the motor may continue to run while the shaft is idle. The clutch is thrown out by an electromagnet 93, the slitting blade being idle while this magnet is energized.

The immediate driving means for the feeding apparatus is a long shaft 99, extending along the machine on the side at which motor 94 is located. As shown in Fig.1, shaft 99 drives shafts 32 and 34 for feed rollers 35 and 36 through bevel gearing 132 between shaft 99 and shaft 32, together with spur gearing 104 between shafts 32, together with spur gearing 1% between shafts 32 and 34-. Shaft 99 extends to the discharge end of the machine where it drives shaft oil through bevel gearing 105 and shaft 6% drives shaft 59 through spur gearing 106. A sprocket chain drive m7 connects shaft 59 and the shaft of roller 62 which serves to roll up the composite, flexible sheet as it is delivered from the machine.

Motor 94 runs constantly but, to allow the veneer to remain stationary while presses are closed on the same, the main shaft 99 must be driven through a suitable clutch. Through mechanism, that includes sprocket chains 93 and N8, the motor drives a sleeve 111 loose on this shaft. Clutch member 112 is fixed to one end of this sleeve, while a cooperating clutch member and cam 114 is slidable on shaft 99; a spring 116 tending constantly to hold clutch member 114 in clutching relation to member 112. Clutch member 114 is controlled by rocking dog 119, which is in turn controlled by a timer cam 122 driven from sleeve 111 through a worm 124 and a worm wheel 125. Clutch member 114, acting as a cam, rocks dogs 119 and, in turn, a shaft to which the dog is fixed. Shaft 130 extends into a switch box 134- that controls electromagnets 91 and 98.

The slitting blade is provided with a stripper which, (as best shown in Fig. 7,) comprises two long strips of soft rubber, 136 and 137, laid flat against opposite sides of the blade with their lower edges located at about the level of the cutting edge of the blade. The strips may be held in place by metal strips 138 and 139; the clamping strips, the rubber strips and the blade being fastened to bar 44 by the same bolts Mil. When the blade enters the veneer, as in Fig. 6, the rubber strips, which bear on the veneer beside the blade, are compressed. Then, when the blade is withdrawn, the rubber strips remain in contact with the veneer and hold the same down until the blade is out of contact with the veneer.

It will thus be seen that I have created a simple machine for progressively slitting a sheet of veneer into narrow strips and simultaneously increasing its length crosswise of the strips; this expansion of the veneer occurring both when the strips are completely separated from each other and when they remain connected by uncut strands or fibers.

It will also be seen that I have created simple means for backing the veneer as it is expanded, thereby not only maintaining the expanded state, but forming a strong, flexible two-ply sheet of indefinite length; the backing being applied While the gaps between the strips are still open, and preventing them from closing. The backing also prevents the widening of the gaps which might occur if the pull of the final feed rolls had to be borne by the veneer; for this pull is transmitted entirely through the solid backing.

I claim:

1. A machine for making a continuous sheet of at least two plies compiising means to feed wood veneer at a constant rate in a forward direction substantially perpendicular to its grain, means in the path of said veneer continuously to convert the veneer into narrow side-byside strips one at a time in a direction along its grain during forward movement of the veneer, the said strips being easily movable toward and away from each other, means for supporting a plurality of said strips in original side-by-side relation so that said strips may move in the direction of said forward feed, means for feeding a continuous flexible sheet in said forward direction at a constant rate greater than said rate of feeding the unconverted veneer, in position to receive and convey said sideby-side strips from said supporting means, whereby to eifect separation of said strips to a predetermined and constant extent by gaps having a width predetermined by the differential rates of said feedings, and means to bond said flexible sheet to said conveyed strips for maintaining said separation.

2. A machine in accordance with claim 1 wherein the means for converting the veneer into strips incompletely severs the strips and leaves connecting strands of wood between the strips, whereby said strands become efiective to limit entry of said flexible sheet into the gaps in manipulation of the composite sheet.

3. A machine for making a continuous sheet of at least two plies comprising means to feed wood veneer at a constant rate in a forward direction substantially perpendicular to its grain, a tapered reciprocatable knife blade arranged progressively to divide the veneer into narrow side-by-side strips in a direction along its grain, means to reciprocate said blade into and out of the veneer to form strips, to move the blade with the veneer when in contact therewith, and to reverse the said last-mentioned movement when out of contact with the veneer, the said strips being easily movable toward and away from each other, means for supporting a plurality of said strips in original side-by-side relation with each other so that said strips may move in the direction of said forward feed, means for feeding a continuous flexible sheet in said forward direction at a constant rate faster than said firstmentioned rate of feed and in a direction to receive and convey said side-by-side strips from said supporting means, whereby to effect separation of said strips to a predetermined and constant extent by gaps having a width predetermined by the differential rates of said feedings, and means to bond said flexible sheet to said conveyed strips for maintaining said separation.

4. A machine in accordance with claim 3 wherein the blade incompletely severs the strips and leaves connecting strands of wood between the strips, whereby said strands become efl'ective to limit entry of said flexible sheet into the gaps in manipulation of the composite sheet.

References Cited in the file of this patent UNITED STATES PATENTS 572,232 Whitten Dec. 1, 1896 907,979 Emens et a1. Dec. 29, 1908 1,052,510 Parker Feb. 11, 1913 1,646,645 Frederickson et a1 Oct. 25, 1927 1,902,032 Horine Mar. 21, 1933 2,454,787 Francek Nov. 30, 1948 2,593,863 Elmendorf Apr. 22, 1952

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