US2928455A - Veneer sheet split closing apparatus - Google Patents

Description

March 15, 1960 H. R. ALBRECHT EIAL 2,928,455

VENEER SHEET SPLIT CLOSING APPARATUS Filed June 4, 1956 5 Sheets-Sheet 1 llvvnvm HERBERT R. ALBRECHT EDWARD H. BAYLEY March 15, 1960 H. R. ALBRECHT EI'AL 2,928,455

VENEER SHEET SPLIT CLOSING APPARATUS Filed June 4, 1956 5 Sheets-Sheet 2 INVENTDRS HERBERT R. ALBRECHT EDWARD H. BAYLEY March 15, 1960 H. R. ALBRECHT ETAL 2,923,455

-- VENEER SHEET SPLIT CLOSING APPARATUS Filed June 4, 1956 5 Sheets-Sheet 3 llvvnvrms HERBERT R- ALBRECHT EDWARD H. BAYLEY March 15, 1960 H. R. ALBRECHT ETAL 2,928,455

VENEER SHEET SPLIT CLOSING APPARATUS Filed June 4, 1956 s Sheets-Sheet 4 we ms, ,140

INVZNTDRS HERBERT R. ALBRECHT EDWARD H. BAYLEY March 15, 1960 H. R. ALBRECHT ETAL 2,928,455

VENEER SHEET SPLIT CLOSING APPARATUS 5 Sheets-Sheet 5 Filed June 4, 1956 wvnvrvn HERBERT R- ALBRECHT EDWARD H. BAYLEY United States Patent VENEER SHEET SPLIT CLOSING APPARATUS Herbert R. Albrecht and Edward H. Bayley, both of Port Alberni, British Columbia, Canada, assignors to Mac- Millan and Bloedel Limited, Vancouver, British Columbia, Canada, a corporation of British Columbia Application June 4, 1956, Serial No. 589,185-

9 Claims. (Cl- 154- -1) This invention relates to apparatus for closing grain splits in the ends of wood veneer sheets.

An object of the present invention is the provision of apparatus for closing splits extending inwardly along the grain from the ends of wood veneer sheets.

Another object is the provision of apparatus for closing grain splits in the ends of wood veneer sheets, and applying adhesive tape to the sheets to keep the splits closed.

Wood veneer sheets for use in the manfacture of ply- Wood or for other purposes often have splits extending along the grain inwardly from the ends thereof. At the present time, this defect is usually remedied by cutting out the wood around the splits, and inserting a wood patch or inlay of a size to fill the hole in the wood. This patching lowers the grade of the plywood in which the sheet is used, and it is comparatively expensive and time consuming.

These defects may be remedied by the present apparatus. The apparatus is designed to close each end split in the panel, and it preferably includes means for applying adhesive tape to the wood over the split in order to keep the latter closed. Then the veneer sheet may be incorporated in a plywood panel in the usual manner.

When the sheet is glued to the next sheet to it in the panel, the tape may be removed since the wood cannot separate to reveal the split. Splits repaired in this manner are usually invisible or are so nearly so that the grade of the panel is not affected thereby.

Apparatus according to this invention includes an anvil against which the end of a wood veneer sheet may be placed, said sheet having a split extending inwardly along the grain from the sheet end, a crosshead mounted for movement towards and'awayfrom the anvil, a pair of pawls pivotally mounted on the crosshead one on each end of the latter, said pawls being inclined towards each other and extending towards the anvil, means for movably retaining the pawls in their inclined positions, said pawls on movement of the crosshead towards the anvil engaging parts of the sheet against the latter on opposite sides of the split thereof and pressing said parts together to close the split, and means near the crosshead for applying a strip of adhesive tape to the sheet at the end thereof across the split to hold the latter closed.

An example of this invention is illustrated in the ac- A companying drawings, in which,

Figure l diagrammatically illustrates the end of a wood veneer sheet having a plurality of splits therein,

Figure 2 diagrammatically illustrates the sheet with the splits closed,

Figure 3 shows. pieces of tape applied to the sheet to hold the splits in the closed position,

Figure 4 diagrammatically illustrates o-net-ype of plywood panel incorporating this veneer 'sheet,

Figure 5 is an elevation of the outfeed end of the apparatus for closing the grain splits,

Figure 6 is a vertical section taken on the line 66 of Figure 5,

ice

Patented Mar. 15, 1960 Figure 7 is a vertical section taken on the line 7--7 of Figure 5.

Figure 8 is a horizontal section taken on the line 88 of Figure 5,

Figure 9 is a horizontal section taken on the line 9-9 ofFigure 6, 1

Figure 10 is a fragmentary vertical sectiontaken on th line 1010 of Figure 9,

Figure 11 is an enlarged vertical section taken onthe line 11-11 of Figure 9,

Figure 12 is an enlarged end elevation of an alternative form of driving arrangement for the various elements of this apparatus, 7.

Figure 13 is asectional view taken on the line 13-13 wood veneer sheet having a plurality of splits. 11 extending inwardly along the grain from its end 12. Figure 2 shows the splits closed, while Figure 3 illustrates how the splits may be kept closed by pieces of tape 13 applied to the sheet and extending across the splits. In Figure 4, the sheet 10 is incorporated in a plywoodpanel 15,

said sheet being glued to the next sheet of the panel thereto so that the splits cannot open again.

Referring to Figures 5 to 10, is a table upon which a plywood sheet 10 may be placed with its end 12 projectingbeyond the edge 21 of the table. With the apparatus illustrated and described herein, the'veneersheet is moved into position by hand, .but it is to be understood that suitable conveyor means may be provided for moving it into and'out of the apparatus.

The split closing apparatusis generally designated by the numeral 25, and it is mounted on table 20in any convenient manner; In this example, the table 20 has a vertical supporting leg 28 to which the apparatus is secured.

Apparatus 25 includes a block .30 having vertical grooves 31 and 32 in its opposite edges. closed by a plate 35 extending thereacross, while groove 32 is closed by a vertical supporting arm 37 extending thereacro'ss. Plate 35 and arm 37 are secured to the block in any desired manner. In this example, a plurality. of bolts 39 extend through the arm, block, plate and leg 28 to hold these parts together and to secure them to the table. An anvil 42 is secured to the upper end of arm 37 and extends inwardly towards table 20. This anvil has a horizontal lower surface 43 which is spaced a little above the upper surface of the table, as clearly shown in Figure 5. This allows the end of the veneer sheet 10 on the table to move beneath the anvil.

A post 46 slidably extends through groove 31 on block the opposite ends of the crosshead by pins 57 and 58, respectively, extending laterally from said head. These pawls are inclined towards each other and extend upwardly towards and beneath anvil 42. The upper ends 5 of these pawls are preferably-provided with tips 60 and 61 formed of a material having a high coeflicient of friction, such as rubber or other suitable substance. It will be noted that when-the piston-rod'48 is retracted, the

Groove 31 is r 3 upper ends of the pawls are spaced downwardly below the anvil, see Figure 6.

i The pawls are resiliently maintainedin their inclined positions in any convenient manner. One way of do ing this'isto provide pawls 55 and 56 with downwardly extending lugs 64 and 65 between which a spring66 ex tends. This spring tends to draw the lugs towards each other, and lug 64 normally bears against aset screw 68 carried by the crosshead, while lug 65 normally bears against a set screw 69. Spring 66'normally draws the lugs'against their respective set screws to maintain the pawls in their inclined positions. However, this spring will permit the pawls to be pivoted inwardly towards each other. If desired, a pre-pressure head 72 may be resiliently mounted on crosshead 53 to project upwardly a little beyond the upper ends of the pawls 55 and 56.. For this purpose, the crosshead may be provided with a vertical extension 74 substantially midway between the ends thereof, said extension having a lug 75 at its upper end extending towards arm 37 of the anvil, see Figure 10. Another lug 76 extends inwardly from the lower edge of the crosshead beneath lug 75, and-a vertical pin 79 is carried bysaid lugs. The pre-pressure head 72 has a downwardly-extendingportion 82 overlapping the crosshead, said portion having spaced lugs 83 and 84 below lugs 75 and 76, respectively. A spring 86 fits around pin 79 and extends between lugs 76 and 83 to keep the pre-pressure head in an upper position, said head being movable downwardly against thetension of the spring. 1 The operation of the apparatus described so far is as follows: a

The veneer sheet is moved: on table 20 until one of the splits 11 thereof is positioned beneath anvil 42. Then air or liquid is directed througha pipe 89 from die. block 99. q

a source and controls, not shown, to cylinder 49 to 1 move piston rod 48 outwardly therefrom. This moves post 46 and crosshead 53 in the same direction.- This movement presses the head 72 against the veneer sheet 10 to move the latter against the surface 43 of anvil 42, thereby flattening out the sheet around the split therein.

When the pawl tips and 61 engage theparts of the veneer sheet on'opposite sides of the split therein, they press the sheet against the anvil, and as the latter is stationary, the pawls pivot inwardly towards each other moving the parts of the wood in the same direction to close the split.

Another post 92 slidably extends through groove 32 of block 30.. The lower end of this post is connected by a pin 93 to the upper end of the piston rod 94 of a pneumatic or hydraulic cylinder 95. Air or liquid is supplied to this cylinder by a pipe 96 extending from a source and controls, not shown. A pressure head or die block 99 is mounted onthe upper end of post 92 to one side of the crosshead 53. This block may be provided with a resilient facing 100 formed of rubber or other suitable material. It will be noted that the die block is on the outside of the crosshead relative to table 20 so that it is positioned beneath the veneer sheet 10 near the end 12 thereof. This die block is intended to press a piece of adhesive tape lying over the top thereof against the surface of the veneer. sheet 10 after the pawls have closed the split therein. While the die block may be set into motion by manually-operated controls, it is preferable automatically to start it into motion after.

' or hydraulic cylinder 155, the lower end of said cylinfrom the table leg 28, see Figure 9. Each bolt has a.

spacer thereon to position the support at a point spaced outwardly from the bracket.

The support 105 has a pin projecting outwardly therefrom for receiving a roll116 of adhesive tape. A strip of tape.11 8 extends from the roll over an idler pulley 120 having" a shaft 121 journalled in the support 105 andin avertical plate.123'spaced outwardly from said support. This plate 123 extends downwardly as indicated at 124 in Figure 11, and has a block 125 at its lowerend which extends laterally therefrom to the support .105 to which 'it is connected by bolts 126,. The tape strip extendsfrom' idler 120 to a roller com- 6 prising a hub 131 having a plurality of spaced knurled discs 132 projecting outwardly therefrom, said hub being mounted on a shaft 133 journalled in support 105 andplate123. -A; stripper roller 136 is mounted adjacent roller 130. Thestripper roller also has a. hub

137 with spaced knurled discs .138 projecting outwardly therefrom, said discs extending'into the spaces. between discs 132 of roller 130. Hub 137 is carried by. a shaft 140 journalled in the support andfplate. .Thestrip of tape moves part way aroundthediscs'of roller 130 and is stripped therefrom by discs 138 of roller 136, the latter roller rotating faster than the former roller in order to produce this effect. From the roller 136, the tape extends over a guide plate 144 carried by the vertical plate 123 and extending'towards the upper surface of A relatively large gear 148 isfreely mounted. on a shaft 149 :carried by support 105 and plate 123, said shaft extending through the former.v An arm 152 is connected to and extends outwardly and downwardly from shaft '149, seeFigure 6. The lower end of this arm is connectedjbya pin 153 to the upper end of a piston 10111154 extending outwardly from a pneumatic der-being mounted on a pivot 156 carried by support 105.

- A ratchet of any'well known design is provided to.

form a connection between gear 148 and shaft 149. In this example, the ratchet includes one element 160 fixed to the shaft; and another element '161 fixed to the gear.

I When the shaft is. rotated in one direction, elements 160 :and 161 are connected for rotation together,'and when the, shaft moves in the opposite direction, element 160 moves relative to element 161. When the piston rod 154 is moved upwardly, arm 152 swings in the same direction to. rotate shaft 149. and this turns gear 148 in the same This. gear: meshes with gear 165 fixedly'mounted on shaft 133. Gear 165 meshes with an idler gear. 166 which, in turn, meshes with another gear 167 fixedly mounted on shaft 140. Gear 167 has 'fewer teeth than 'gear 165 so that the former rotates the cros'shead has moved upwardly a predetermined dis- 7 lengths of adhesive tape over. the top of the die block.

99. This unit includes a vertical support 105 mounted adjacentanvil 42 injany, convenient manner. lnthis example, a plurality of bolts 107 extend through this support and through a bracket 109 extending laterally 'edge 172 which extends transversely of the block.

faster. than the latter. With this arrangement, rollers 130 and 136 are rotated in the same direction but at different speeds when. gear 148 is rotated by 'shaft 149. .Theturning of roller .130 draws the strip of tape 118 from tape roll 1 16, and the discs of roller 136st'rip the tape strip from the discs 132. At the same time, the

tape is. moved over guide 144 on to the top of die block 99. I V t The die block 99 is provided with a knife blade extendingupwardly slightly beyond the top thereof at its edge facing the tape unit 102'. This blade has a cutting desired, air may be blown along the portionof the tape lying over die block 99 -in order to prevent said tape from curlingupwardly. Anozzle'. 176 may be provided for this purpose. .The. nozzle 'is ;.carried by plate123 over guide plate 144, see Figures 9 and 11. This nozzle has an outlet 178 facing 'generally towards the die block, and air is supplied to the nozzle by a pipe 179 extending from a source, not shown. 4 V j j When the' apparatus is in operation, air is directed by nozzle 176 along the upper surface of the strip of tape F v G extending towards and over the die block. This prevents the tape from curling upwardly, and it has a tendency to form a low pressure area along the upper surface of the tape, thereby normally keeping it clear of the block.

As previously described, when the die block is moved upwardly, it presses a strip of tape overlying its upper end against the surface or" the veneer sheet positioned beneath anvil 42. The resilient facing 100 of the block ensures a good bond between the tape and wood even when the latter is relatively uneven. As this takes place, blade 170 cuts the tape away from the strip thereof extending from the tape roll. When the die block is lowered, another piece of tape is moved over the top thereof through the operation of cylinder 155. This may be done by the operator of the machine, or it may be done automatically by a switch, not shown, operated by the die block as the latter moves downwardly. This causes piston rod 154 to be moved outwardly of the cylinder, and another strip of tape is moved over guide 344 and along over the top of the block. With this arrangement, when the die block moves upwardly, the switch would be released to allow the piston rod to be retracted into its cylinder.

As previously stated, each portion of the apparatus may be set into operation by the operator. However, it is preferable to have the apparatus operate in sequence. When the veneer sheet is moved to a position with a split under anvil 42 and between pawls 55 and 56, the operator then starts the apparatus in motion. Cylinder 49 moves the crosshead and pawls upwardly to move the parts of the wood on opposite sides of the split to close the latter, then the die block 92 moves upwardly to press the tape strip overlying it against the wood to keep the split closed. This movement of the die block causes knife 170 to sever the piece of tape from the main strip thereof. When the die bloclt moves downwardly, the tape unit is operated to move another piece of tape over said bloclt.

Although it is preferable to have the anvil over the pawls and die block, it is obvious that the positions of these elements may be reversed so that the pawls and die block move downwardly during operation. Furthermore, it is desirable to use adhesive tape, but it is to be understood that any type of binding material may be used and glue supplied thereto during operation of the machine.

in the above-described form of the invention, the pawls 55 and 56, die block 99 and the feeding mechanism of the tape supplying unit 102 are operated by pneumatic or hydraulic cylinders. Figures 12 to 14 illustrate mechanical means for operating these elements.

For this purpose, a shaft 180 is mounted in suitable bearings 181 and extends beneath the vertical posts 46 and 92. This shaft is connected by a one-revolution clutch 13 to an electric motor 185 or other source of power. This clutch is the type that when engaged, it causes shaft 180 to make one revolution, after which it automatically disengages. Cams 186, 188 and 1% are fixedly mounted on this shaft. Cams 186 and 19% are located beneath and spaced from posts 46 and 92, respectively. Cams 135, 183 and 190 have projecting therefrom respectively lobes 192, 1% and 3.96. Lobes 192 and 196 are substantially opposite each other, see Figure 13, but the former has an inclined leading edge 198 which is in advance, with reference to the direction of rotation of the cams, of an inclined leading edge 200 on lobe 106. The trailing edges 201 and 202 of these cams are in line. Lobe 194 is behind the trailing edges 201 and 202 of the other cams with reference to the direction of rotation. 7

Cam followers 205 and 207 are connected to and project downwardly from posts 46 and 92 respectively, and have rollers 208 and 209 riding respectively on cams 186 and 190. V

A comparatively long cam follower 212 is connected at its upper end at 213 to the arm 152 of the tape unit 102. This follower is inclined downwardly and has a roller 214 at its lower end riding on cam 188.

As clutch 184 may be any of different clutches on the market, its construction and operation is not described herein. This clutch has an operating mechanism, not shown, and when this mechanism is operated, theclutch connects shaft 180 to the source of power for one revolution, and then the clutch automatically disengages. This action turns cams 186, 188 and 190 through one revolution. With the cams in the position shown in Figures 12 and 13, arm 52 has just been moved to direct a piece of tape over die'block 99. When the cams start to move, follower 212 and arm 152 move downwardly, ratchet 160161 allowing this to take place without any movement in the tape unit. At the same time, follower 205 and post 46 are moved upwardly by lobe 192 of earn 186. This moves the pawls 55 and 56 upwardly to close the split in the wood veneer positioned on table 20 with its end beneath anvil 42. By the time 7 this action is completed, follower 207 and post 92 are raised by lobe 196 of cam 190. This moves die block 99 upwardly to press v the tape against the veneer sheet, over the closed split, and severs this piece of tape from the strip extending from the tape roll 116. Followers 205 and 207 drop downwardly from their lobes at the same time, and this is followed by follower 212' being raised by the lobe 194 of cam 188. This swings arm 152 upwardly to cause another piece of tape to be moved out over the die block. The cams now stop moving and the apparatus is ready for the next operation of clutch 184.

What we claim as our invention is:

1. In apparatus for closing grain splits in the ends of wood veneer sheets, an anvilagainst whichv the end of a wood veneer sheet may be placed, said sheet having a '7 split extending inwardly along the grain from the sheet end, a crosshead mounted for movement towards and away from the anvil,v a pair of pawls pivotally mounted on the crosshead one on each end of the latter, said pawls being inclined towards each other and extending towards the anvil, means movably retaining the pawls in their inclined positions, said pawls on movement of the cross' head towards the anvil engaging parts of the sheet against the latter on opposite sides of the split thereof and pressing said parts together to close the split, and means near the crosshead for applying a strip of adhesive tape to the sheet at the end thereof across the split to hold the latter closed.

2. In apparatus for closing grain splits in the ends of wood veneer sheets, an anvil against which the end of a wood veneer sheet may be placed, said sheet having a split extending inwardly along the grain from the sheet end, a crosshead mounted formoveinent towards and away from the anvil, a pair of pawls pivotally mounted on the crosshead one on each end of the latter, said pawls being inclinedtowards each other and extending towards the anvil, a rubber tip on the outer end of each pawl, a spring connected to the pawls and resiliently retaining them in their inclined positions, the tips of said pawls on movement of the crosshead towards the anvil engaging parts of the sheet against the latter on opposite sides of the split thereof and pressing said parts together to close the split, and means near the crosshead for applying a strip of adhesive tape to the sheet at the end thereof across the split to holdthe latter closed. 7

. 3. 111 apparatus for closing grain splits in the ends of wood veneer sheets, an anvil against which the end of a wood veneer sheet may be placed, said sheet having a split extending inwardly along the grain from the sheet end, a crosshead mounted for movement towards and away from the anvil, a pair of pawls pivotally mounted on the crosshead one on each end of the latter, said pawls being inclined towards each other and extending towards 4. In apparatus for closing grain splits in the ends of wood veneer sheets, an anvil against which the end of a wood veneer sheet may be placed, said sheet having a split extending inwardly along the grain from thefsheet end, 'a crosshead mounted for move ment towards and away from'the anvil, a pair of pawls pivotally mounted on the crosshead one on each end of the latter, said pawls being inclined towards each other and extending towards the anvil, means movably retaining the pawls in their inclined position, said pawls on movement of the crosshead towards the anvil engaging parts of the sheet against the latter on opposite sides of the split thereof and pressing said parts together to close the split, a pressure head mounted near the crosshead for movement towards and away from the anvil, means beside the head for moving a strip of adhesive tape from a roll between the head and the sheet, a knife blade on the head projecting towards the anvil, and means connected to the head for moving it and the blade towards the anvil simultaneously to cut the tape from the roll and press said tape against the sheet across the split to hold the latter closed.

5. In apparatus for closing grain splits in the ends of wood veneer sheets, an anvil against which the end of a wood veneer sheet may be placed, said sheet having a split extending inwardly along the'grain from the sheet end, a crosshead mounted for movement towards and away from the anvil, a pair of pawls pivotally mounted on the crosshead one on each end of the latter, said pawls being inclined towards each other and extending towards the anvil,means movably retaining the pawls in their inclined positions, a pre-pressure head resiliently mounted on the crosshead and extending towards the anvil a little farther than the pawls, said pre-pressure head and the pawls onmovement of the crosshead towards the anvil successively engaging parts of the sheet against the latter on opposite sides of the split therein first to flatten the sheet parts against the anvil and then to press said parts together to close the split, and means'near the crosshead for applying a strip of adhesive tape to the sheet at the end thereof across the split to hold the latter closed.

6. In apparatus for closing grain splits in the ends" ofwood veneer sheets, an anvil against which the end of a wood veneer sheet may be placed, said sheet having a split extending inwardly along the grain from the sheet end, a crosshead mounted for movement towards and away fromthe anvil, a pair of pawls pivotally mounted on the crosshead one on each end of the latter, said pawls being inclined towards each other and extending towards the anvil, means movably retaining the pawls in their inclined positions, said pawls on movement of the crosshead towards the anvil engaging parts of the sheet against the latter on opposite sides of the split thereof and pressing said parts together to close the split, a pressure head mounted near the anvil for movement towards and away therefrom, means beside the head for moving a strip of adhesive tape between it and the sheet, and means conclosed. I

nected to the head for moving it towards the anvil to press the tape against the sheet across the split to hold the latter wood veneer sheet may be placed, said sheet having a split extending inwardly along the grain from the sheet end, a crosshead mounted for movement towards and away from the anvil, a pair of pawls pivotally mounted on the crosshead one on each end of the latter, said pawls being inclined towards each other and extending towards the anvil, means movably retaining the pawls in their inclined positions, said pawls on movement of the crosshead towards the anvil engaging parts of thesheet against the latter on opposite sides of the split thereof and pressing said parts together to close the split, a pressure head mounted near the anvil 'for movement towards and away therefrom, means beside the head for moving a strip of adhesive tape from a roll between the head and the sheet, a knife bladeon the head projecting towards the anvil, and means connected tothe head for moving it and the blade towards'the anvilsimultaneously to cut the tape from the roll and press said tape against the sheet across:

crosshead that when the latter is moved towards the anvil said pawls engage parts of the sheet against the anvil on opposite sides of the split thereof and press said parts together to close the split, a pressure head mounted near the cross head for movement towards and away from the anvil, means beside the head for moving a strip of adhesive tape from a roll between the head and the sheet,

a knife blade on the head projecting ,towardsthe anvil,

and means connected to the head for moving it and the blade towards the anvilsimultaneously to cut the tape from the roll and press said tape against the sheet 'across the split to hold the latter closed.

9. In apparatus for closing grainsplits in the ends of wood veneer sheets, an anvil against which the ends of a wood veneer sheet may be placed, said sheet having a split extending inwardly along the grain from the sheet end, a crosshead mounted for movement towards .and away from the anvil, a pair of pawls so mounted on the crosshead that when the latter is moved towards the anvil said pawls engage parts of the sheet against the anvil on 'opposite sides of the split thereof and press said parts together' to close the split, a pro-pressure head, resiliently mounted on the crosshead andextending towards the :anyil a little farther than the pawls, said pre-pressure head on movement of the crossheadtowards the anvil References: Cited in the file of this patent Australia -4..- Nov. 30, 1949

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