Vacuum flitch table for veneer slicer

Claim 2

A veneer slicer comprising a reciprocable flitch table, a knife and pressure bar assembly movable toward and away from the path of reciprocation of said flitch table, and means for reciprocating said flitch table, in which the improvement comprises vacuum means for holding flitches to said table, said vacuum means including a vacuum source, at least one vacuum cell plate mounted on said flitch table for movement therewith, said cell plate providing a front surface facing said knife and pressure bar assembly and against which a flitch is held, said cell plate providing a plurality of cell areas in said front surface, sealing means extending about each cell area, conduit means for connecting said cell areas to said vacuum source, said conduit means including, for each cell area, valve means, each said valve means including means for determining when its associated cell area is completely covered by a flitch and opening said cell area to said vacuum source only when it is completely covered by a flitch, said determining means including actuating means for opening said valve means to air flow from said cell area to said vacuum source, the air flow from said cell area being sufficient to close said valve means when said cell area is not completely covered and insufficient to close said valve means when said cell area is completely covered.

Claim 3

The improvement of claim 1 in which each valve means includes means providing a valve passageway having a first valve seat therein, and a valve member movable against said first valve seat to close said passageway, thereby closing its associated cell area to said vacuum source, said actuating means including means for holding said valve member away from said first valve seat and releasing said valve member for movement against said first valve seat by the air flow from said cell area when said cell area is not completely covered such that a vacuum can form therein.

Claim 4

The improvement of claim 2 in which said passageway provides a second valve seat spaced apart from said first valve seat, said valve member being movable between said seats and movable against said second seat to close said passageway, said actuating means being effective to move said valve member against said second seat and hold it there while a flitch is being placed against said front surface and to release said valve member for movement towarD said first valve seat when the flitch is against said front surface.

Claim 5

The improvement of claim 3 in which said valve member is a spherical ball having a first diameter, said passageway being cylindrical and having a second and greater diameter, said valve seats being conical and facing each other, whereby, when the associated cell area is completely covered such that a vacuum is formed therein, said ball stays out of engagement with said seats to open said cell area to said vacuum source.

Claim 6

The improvement of claim 2 in which each actuating means includes an air actuated plunger for moving said valve member, a source of compressed air, and conduit means connecting said plungers to said source of compressed air.

Claim 7

The improvement of claim 5 in which said conduit means includes valve means for simultaneously supplying air under pressure to said plungers and simultaneously exhausting the air from said plungers, said conduit means including selectively variable orifice means through which the air under pressure is exhausted, whereby the speed of movement of said plungers in releasing said valve members is controlled.

Claim 8

The improvement of claim 4 in which each actuating means includes an air actuated plunger for moving its associated ball against said second valve seat, holding it there, and releasing it for movement toward said first valve seat, a source of compressed air, and condiut means connecting said plungers to said source of compressed air.

Claim 9

The improvement of claim 7 in which each actuating means includes spring means for yieldably urging its associated plunger to its retracted, ball releasing position, the compressed air conduit means including valve means for simultaneously supplying air under pressure to said plungers and simultaneously exhausting the air from said plungers, and selectively variable orifice means through which the air under pressure is controlled and by which the speed of movement of the plungers in releasing the balls is controlled.

Claim 10

The improvement of claim 5 in which said cell plate provides a back surface having a plurality of cavities therein in registry respectively with said cell areas, a rubber diaphragm covering said back surface and said cavities, said conduit means for the compressed air including a base plate having air passageways formed therein, portions of which overlie said cavities, whereby positive air pressure in said passageways deflects the portions of said diaphragm overlying said cavities, said plungers being movable by said deflecting diaphragm portions, and spring menas for yieldably resisting movement of said plungers by said diaphragm portions.

Claim 11

In a veneer slicer comprising a knife assembly, and a reciprocable flitch table on which flitches are mounted for reciprocation relative to said knife assembly, the improvement comprising a vacuum system for holding flitches to said flitch table, said system comprising a vacuum pump, means providing a plurality of cell areas opening toward said knife assembly and against which flitches are held, sealing means bounding each cell area sealably to engage the flitches, valve means for connecting each cell area to said vacuum pump, each valve means including means providing a valve passageway communicating between its associated cell area and said vacuum pump, a valve member for closing said passageway, and plunger means for shifting said valve member away from its position closing said passageway and releasing said valve member for movement controlled by the air flow from the cell area through said passageway, the air flow being insufficient to move the valve member to its closing position when the cell area is completely covered.

Claim 12

In a veneer slicer comprising a knife assembly, and a reciprocable flitch table on which flitches are mounted for reciprocation relative to said knife assembly, the improvement comprising a vacuum system for holding flitches to said flitch table, said system comprising a vacuum pump, means providing a plurality of cell areas opening toward said knife assembly and against which flitches are held, sealing means bounding each cell area sealably to engage the flitches, valve means for connecting each cell area to said vacuum pump, each valve means including means providing a valve passageway communicating between its associated cell area and said vacuum pump, a valve member for closing said passageway, and plunger means for shifting said valve member away from its position closing said passageway and releasing said valve member for movement controlled by the air flow from the cell area through said passageway, the air flow being insufficient to move the valve member to its closing position when the cell area is completely covered.

Claim 13

The improvement of claim 10 in which each said plunger means includes an air actuated plunger for moving said valve member, a source of compressed air, and conduit means connecting said plungers to said source of compressed air.

Claim 14

The improvement of claim 11 in which each said plunger is effective to move the assoCiated valve member away from its closing position, to hold it away from its closing position while a flitch is being placed against the associated cell area, and to release said valve member for movement toward its closing position when the flitch is against the cell area.

Claim 15

The improvement of claim 12 in which said valve member and said passageway are proportioned and designed such that, when the cell area is completely covered and evacuated, the pressure on opposite sides of said valve member is equalized such that said valve member, when released, will not move to its closing position.

Claim 16

The invention of claim 10 in which said means providing a plurality of cell areas includes at least one cell plate providing a front surface including said cell areas and a back surface, said back surface having a plurality of cavities therein in registry, respectively, with said cell areas, said valve passageways communicating respectively between said cell areas and said cavities, said plunger means including a diaphragm covering said back surface and said cavities, a base plate covering said diaphragm, said base plate having air passageways therein, portions of which overlie said cavities, a source of compressed air and means for connecting said source of compressed air to the passageways in said base plate, whereby compressed air in said passageways will deflect the portions of said diaphragm overlying said cavities, and plungers in said cavities movable by said deflecting diaphragm portions to move said valve members.

Claim 17

The improvement of claim 14 in which each valve passageway has a first conical valve seat facing the associated cell area and an axially spaced apart second conical valve seat facing said first valve seat, said valve member being a spherical ball movable between and engageable with said seats, said passageway having a diameter greater than said ball such that said passageway is closed by said ball only when said ball is engaging one of said seats, the plunger associated with said valve passageway being effective to move said ball against said second seat and to hold it there when a flitch is being placed against said associated cell area and then to release said ball for movement toward said first seat, said ball and valve passageway being proportioned and designed such that, if said cell area is not completely recovered, the movement of air from said cell area through said valve passageway will move said ball into sealing engagement with said first seat and, if cell area is completely covered such that a vacuum is formed therein, said ball will stay between said seats to keep said cell area open to said vacuum pump.

Claim 18

The improvement of claim 15 including selectively variable orifice means for exhausting the compressed air from said passageways in said base plate to control the speed of movement of the plungers in releasing said balls for movement toward said first valve seats.

Claim 19

The improvement of claim 12 including selectively variable orifice means for exhausting the compressed air from said conduit means to control the speed of movement of said plungers in releasing said valve members for movement toward their closing positions.

Claim 20

The improvement of claim 16 including spring means yieldably resisting the movement of said plungers by said diaphragm.

Claim 21

The improvement of claim 12 including spring means for yieldably urging each plunger toward its releasing position.

Claim 22

In a veneer slicer comprising a flitch table providing a mounting surface, a plurality of dogs for gripping a flitch at a first distance from said mounting surface and holding the flitch securely against a central portion of the mounting surface, a plurality of extension dog assemblies mounted on said flitch table to grip a flitch at a second and greater distance from the mounting surface, each extension dog assembly including opposing jaws positioned to engage generally opposite portions of a flitch, means for guiding said jaws for movement toward said central portion to their gripping positions and away from said central portion to their releasing positions, and power means for moving said opposing jaws between their respective gripping and releasing positions, means for reciprocating said flitch table in the plane of said mounting surface, and a knife assembly movable along a path toward and away from said mounting surface, the improvement comprising vacuum means for holding flitches to said table, said vacuum means including a vacuum source, at least one vacuum cell plate mounted on said flitch table for movement therewith, said cell plate being secured to said flitch table mounting surface by the gripping action of said first mentioned dogs, said cell plate being disposed between a pair of said extension dog assemblies such that the jaws of said assemblies can engage a flitch and hold it against said cell plate, said cell plate providing a front surface facing said knife assembly and against which the flitch is held, said cell plate providing a plurality of cell areas in said front surface, conduit means for connecting said cell areas to said vacuum source, said conduit means including, for each cell area, valve means effective to open said cell area to said vacuum source only when said cell area is completely covered by a flitch, each valve means including means providing a valve passageway from said cell area to said vacuum source, a valve member having a position closing said passageway, and actuating means for moving said valve member away from said closing position and releasing said valve member for movement controlled by the air flow from said cell area to said vacuum source, the amount of air flow being sufficient to move said valve member to said closing position when the cell area is not completely covered such that a vacuum can form therein.

Claim 23

In a veneer slicer comprising a flitch table providing a mounting surface, a plurality of dogs for gripping a flitch at a first distance from said mounting surface and holding the flitch securely against a central portion of the mounting surface, a plurality of extension dog assemblies mounted on said flitch table to grip a flitch at a second and greater distance from the mounting surface, each extension dog assembly including opposing jaws positioned to engage generally opposite portions of a flitch, means for guiding said jaws for movement toward said central portion to their gripping positions and away from said central portion to their releasing positions, and power means for moving said opposing jaws between their respective gripping and releasing positions, means for reciprocating said flitch table in the plane of said mounting surface, and a knife assembly movable along a path toward and away from said mounting surface, the improvement comprising vacuum means for holding flitches to said table, said vacuum means including a vacuum source, at least one vacuum cell plate mounted on said flitch table for movement therewith, said cell plate being secured to said flitch table mounting surface by the gripping action of said first mentioned dogs, said cell plate being disposed between a pair of said extension dog assemblies such that the jaws of said assemblies can engage a flitch and hold it against said cell plate, said cell plate providing a front surface facing said knife assembly and against which the flitch is held, said cell plate providing a plurality of cell areas in said front surface, conduit means for connecting said cell areas to said vacuum source, said conduit means including, for each cell area, valve means effective to open said cell area to said vacuum source only when said cell area is completely covered by a flitch, each valve means including means providing a valve passageway from said cell area to said vacuum source, a valve member having a position closing said passageway, and actuating means for moving said valve member away from said closing position and releasing said valve member for movement controlled by the air flow from said cell area to said vacuum source, the amount of air flow being sufficient to move said valve member to said closing position when the cell area is not completely covered such that a vacuum can form therein.

Claim 24

The improvement of claim 20 in which said valve passageway provides a first valve seat therein facing the said cell area, said valve member being movable against said first seat to close said valve passageway, thereby closing the associated cell area to said vacuum source, and said actuating means being effective to move said valve member away from said first seat toward said cell area, hold it away from said first seat while a flitch is being placed against said front surface, and then release it for movement toward said first seat when a flitch is against said front surface, said valve member and said passageway being proportioned and designed such that, if said cell area is not completely covered, the movement of air from said cell area through said passageway will move said valve member into sealing engagement with said first seat and, if said cell area is completely covered such that a vacuum is formed therein, said valve member will not move against said first seat.

Claim 25

The improvement of claim 21 in which said passageway provides a second valve seat spaced apart from and facing said first valve seat, said member being movable between and sealably engageable with both of said valve seats, said actuating means being effective to move said valve against said second seat and hold it there while a flitch is being placed against said front surface and to release said valve member for movement toward said first valve seat when the flitch is against said front surface.

Claim 26

The improvement of claim 22 in which each actuating means includes an air actuated plunger for moving said valve member, a source of compressed air, and conduit means connecting said plungers to said source of compressed air.

Claim 27

The improvement of claim 23 in which said conduit means includes valve means for simultaneously supplying air under pressure to said plungers and simultaneously exhausting the air from said plungers, said conduit means including selectively variable orifice means through which the air under pressure is exhausted, whereby the speed of movement of said plungers in releasing said valve members is controlled.

Claim 28

The improvement of claim 23 in which said cell plaTe provides a back surface having a plurality of cavities therein in registry respectively with said cell areas, a rubber diaphragm covering said back surface and said cavities, said conduit means for the compressed air including a base plate having air passageways formed therein, portions of which overlie said cavities, whereby positive air pressure in said passageways deflects the portions of said diaphragm overlying said cavities, said plungers being movable by said reflecting diaphragm portions, and spring means for yieldably resisting movement of said plungers by said diaphragm portions.

Claim 29

The improvement of said claim 22 in which said means providing a valve passageway includes a cylindrical cell body threadedly engaged into said cell plate, said cell body having a coaxial threaded cylindrical bore therein providing said second valve seat, an orifice member threadedly engaging said bore and providing said first valve seat, said seats being frusto-conically shaped, said valve member being a ball, the diameter of which is less than the diameter of said bore.

Claim 30

The improvement of claim 26 in which each said cell body extends axially outwardly from said front surface, and a sharpened dogging device mounted on each cell body to engage the flitch held thereagainst.

Claim 31

The improvement of claim 26 in which each actuating means includes an air actuated plunger for moving said ball, a source of compressed air, and couduit means for connecting said plunger to said source of compressed air, said plunger extending through said orifice member to engage said ball.

Claim 32

The improvement of claim 28 in which said conduit means includes valve means for simultaneously supplying air under pressure to said plungers and simultaneously exhausting the air from said plungers, said conduit means including selectively variable orifice means through which the air under pressure is exhausted, whereby the speed of movement of said plungers in releasing said valve members is controlled.

Claim 33

The improvement of claim 27 in which said cell plate includes a rubber-like mat forming said front surface, said mat having openings therein defining said cell areas.