Veneer defect detector and clipper control

Claim 3

The apparatus as defined in claim 1 wherein said means for producing cutting command signals includes: means located a predetermined distance from said cutting device in a direction opposite to the direction of the sheet material flowing into said cutting device to provide a shadow line reference location including a source of light illuminating said moving sheet material and means between said light and said sheet material for producing a shadow line extending transversely across said sheet material; and manually operated switch means which may be actuated to produce cutting command signals to be applied to either said first and second circuit means as a defective portion of said sheet material passes under said shadow line.

Claim 4

The apparatus as defined in claim 1 wherein said means to produce cutting command signals includes: means located a predetermined distance from said cutting device to provide for defect detection prior to the defect moving into said cutting device including; radiation producing means located on one side of said sheet material, said radiation being directed toward said sheet material with a greater portion of the radiation passing through the sheet material in the areas where defects occur; radiation sensing means located on the opposite side of said sheet material from said radiation producing means to receive the transmitted radiation; and output means connected to said radiation sensing means to produce cutting command signals upon a change in the intensity of the radiation transmitted through said sheet material as a result of a defective area passing between said radiation source and said radiation detecting means.

Claim 5

The apparatus as defined in claim 1 wherein said cutting device includes a knife mounted to be actuated through the cutting and return stroke by the movement of a toggle bar from one limit position to another limit position and includes means to reciprocate the toggle bar upon the application of successive actuating signals thereto; and wherein switching means are included for selecting either the first or the second circuit means in response to the position of saId toggle bar whereby the time delay characteristics of each of said first and second circuit means are maintained in synchronism with the operation of said cutting device.

Claim 6

The apparatus as defined in claim 1 wherein each of said first and second circuit means includes: an operational amplifier; a ramp generator; a voltage comparator operably connected to said operational amplifier and said ramp generator for developing an actuating signal to be applied to said cutting device when the output from said ramp generator equals the output from said operational amplifier; and wherein the means responsive to said feedback signal and said reference signal is operably connected to said operational amplifier to modify the output from said operational amplifier in such a way that the actuating signal developed by said voltage comparator occurs at such a time in advance of the actual cutting of the sheet material that the sheet will actually be cut at the preselected location.

Claim 7

The apparatus as defined in claim 1 further including means associated with said sheet material for producing an output signal for specified lengths of travel of sheet material; and wherein said apparatus further includes means connected to said output means for delaying the application of the cutting command signals to either the first or second circuit means until the sheet material has moved from the means producing the cutting command signals substantially to the cutting device.

Claim 8

The apparatus as defined in claim 1 further including memory means for sensing the occurrence of cutting command pulses which are spaced together too closely for the proper operation of the cutting device, said memory means resupplying the later, closely spaced cutting command signals to said first and second circuit means after a delay sufficient to permit the subsequent operation of said cutting device.

Claim 9

The apparatus as defined in claim 1 wherein said means for producing cutting command signals comprises: radiation producing means positioned on one side of said sheet material, said radiation being directed toward said sheet material with a greater portion of the radiation passing through the sheet material in areas where defects in the sheet material occur; radiation sensing means positioned on the opposite side of said sheet material to receive the radiation transmitted therethrough; reference means connected to the output of said radiation sensing means to measure momentarily the intensity of the radiation transmitted through said sheet material prior to the sensing of a defect to provide a reference level indicating the intensity of the radiation transmitted through an acceptable portion of the sheet material; and means comparing said reference level to the output from said radiation sensing means to provide a first cutting command signal when the intensity of the radiation transmitted through said sheet material increases above said reference level and to provide a second cutting command signal when the intensity of the radiation passing through said sheet material thereafter decreases.

Claim 10

The apparatus as defined in claim 1 wherein said means for producing cutting command signals comprises: radiation producing means positioned on one side of said sheet material with the radiation therefrom directed toward said sheet material; radiation sensing means positioned on the opposite side of said sheet material to receive the radiation transmitted therethrough; means connected to said radiation sensing means to provide a first signal when the intensity of the radiation transmitted through said sheet material increases thereby indicating the beginning of a defect and to provide a second signal when the radiation passing through said sheet material decreases thereby indicating the end of the defect; means for producing an output signal for specified lengths of travel of the sheet material; means connected to said output signal producing meanS and responsive to said first signal to produce a first cutting command signal after the sheet has traveled a first predetermined distance after the occurrence of the first signal; further means connected to said output signal producing means and responsive to said second signal for producing a second cutting command signal after the sheet has traveled a second predetermined distance after the occurrence of said second signal; and whereby the defect may be cut from the sheet material a predetermined distance prior to the defect and a predetermined distance after the defect thereby to insure complete removal of the defect from the sheet material.

Claim 11

The apparatus as defined in claim 1 wherein said means for producing cutting command signals includes: radiation producing means located on one side of said sheet material; radiation sensing means located on the opposite of said sheet material to sense the intensity of the radiation transmitted therethrough; means connected to the output of said radiation sensing means to measure momentarily the intensity of the radiation passing through said acceptable sheet material prior to the sensing of a defect and thereby to provide a reference level; comparator means to compare thereafter the reference level with the output from said radiation sensing means to provide a first signal in response to an increase in the intensity of the radiation above-said reference level and to produce a second signal in response to a decrease in the intensity of the radiation to or below said reference level; first delay means responsive to said first signal to produce a cutting command signal to be applied to either said first or said second circuit means at such a time that the sheet material will be cut a predetermined distance prior to the defect as observed by said radiation sensing means; and a second delay means responsive to said second signal to produce a cutting command signal to be applied to the other of said first or second circuit means at such a time that the sheet material is cut a predetermined distance after the defect as observed by said radiation sensing means.

Claim 12

The apparatus as defined in claim 1 wherein said means for producing cutting command signals includes: radiation producing means located on one side of said sheet material; radiation sensing means positioned on the opposite side of said sheet material to receive the radiation transmitted therethrough, said radiation sensing means including a plurality of photocells arranged to extend transversely across said sheet material; means connected to said plurality of photocells to produce a cutting command pulse when the output from said photocells increases above a predetermined value; and means sending the individual output of the photocells at each edge of the sheet material to disable selectively the output from each of said photocells to said cutting command signal producing means when said photocells become uncovered and to enable selectively a corresponding photocell at the opposite edge of said sheet material thereby permitting the lateral movement of the entire sheet without producing a cutting command signal indicating a defect provided the corresponding photocell at the opposite edge of the sheet becomes covered by said sheet material.

Claim 13

The apparatus as defined in claim 1 wherein sheet material having a predetermined minimum continuous width may be separated from the remainder of the sheet material, said apparatus including: radiation producing means positioned on one side of said sheet material; a plurality of radiation responsive photocells positioned on the opposite side of said sheet material and aligned to receive the radiation transmitted through said sheet material; and circuit means connected to the output of said photocells for providing a cutting command signal when a predetermined number of consecutive photocells indicate the presence of acceptable sheet material correspondiNg to the predetermined minimum width, said circuit means further providing a cutting command signal when the number of consecutive photocells indicating the acceptable minimum predetermined width does not include the original photocells indicating the minimum predetermined width of acceptable sheet material.

Claim 14

The apparatus as defined in claim 1 wherein said means to produce cutting command signals includes: means operably associated with said moving sheet material to produce output signals after specified lengths of sheet material have moved through said cutting device; and means connected to said output means to provide cutting command signals after the sheet material has moved a predetermined distance through said cutting device since the last cutting command signal thereby to cut the sheet material into standard predetermined lengths.

Claim 15

The apparatus as defined in claim 1 wherein said means to produce cutting command signals includes: means operably connected with said moving sheet material to produce output signals after specified lengths of sheet material have moved through said cutting device; means connected to said output means to provide cutting command signals after the sheet material has moved a first predetermined distance since the last cutting command signals provided another cutting command signal has not been applied to said first or second circuit means within said first predetermined distance; means to produce another cutting command signal after the sheet material has moved a second further predetermined distance since the last cutting command signal provided that no cutting command signal occurs within said second predetermined distance; and means to inhibit said cutting command signal at said first predetermined distance in the event that a cutting signal is produced at said second predetermined distance thereby to cut the sheet material only at the second or longer predetermined distance.

Claim 16

Apparatus for cutting a strip of moving material including: a cutting device; means for producing cutting command signals upon the passage of defects in the material a predetermined distance in advance of said cutting device; output means operably associated with the moving material in advance of said cutting device to produce output signals for specific increments of movement of the material; second means responsive to the output signals from said output means and further responsive to the cutting command signals from said first means for providing additional cutting command signals after predetermined lengths of material have moved through said cutting device since the last cutting command signal; and delay circuit means connected to receive said cutting command signals from said first and second means and responsive to the output of said output means for providing actuating signals to said cutting device after the material has moved said predetermined distance.

Claim 17

Apparatus for cutting a strip of moving material including: a cutting device; means for producing cutting command signals upon the passage of defects in the material a predetermined distance in advance of said cutting device; output means operably associated with the moving material in advance of said cutting device to produce output signals for specific increments of movement of the material; second means responsive to the output signals from said output means and further responsive to the cutting command signals from said first means for providing additional cutting command signals after predetermined lengths of material have moved through said cutting device since the last cutting command signal; and delay circuit means connected to receive said cutting command signals from said first and second means and responsive to the output of said output means for providing actuating signals to said cutting device after the material has moved said predetermined distance.

Claim 18

Apparatus of claim 15 wherein said second means includes means for producing a cutting command signal after a first predetermined length of material has moved through said cutting device since the last cutting command signal and means for producing another cutting command signal after the material has moved a second, further predetermined length through said cutting device, and means to inhibit said cutting command signal at said first predetermined length in the event that a cutting command signal is produced at said second predetermined length thereby to cause the material to be cut at said second predetermined length.

Claim 19

The apparatus of claim 15 wherein said first means for producing cutting command signals is a manually actuated switch.

Claim 20

The apparatus of claim 15 wherein said first means for producing cutting command signals is a sensing device responsive to radiation transmitted through the material upon the passage of a defect in the material across said sensing device.

Claim 21

Apparatus for use with a cutting device for cutting a strip of moving material, the combination including: first means located a predetermined distance in advance of said cutting device for producing first and second cutting command signals indicating the passage of the beginning and end of a defect in the material, respectively; output means associated with said material in advance of said cutting device for producing output signals for specified lengths of travel of the material; means connected to said output means and responsive to the first cutting command signal from said first means indicating the beginning of a defect to produce a first actuating signal to said cutting device after the material has traveled a first predetermined distance from the occurence of said first cutting command signal; further means connected to said output means and responsive to the second cutting command signal from said first means indicating the end of the defect to produce a second actuating signal after the material has traveled a second predetermined distance from the occurrence of said second cutting command signal; and whereby the material is cut a first predetermined distance prior to the defect and a second predetermined distance after the defect thereby to insure complete removal of the defect from the material.

Claim 22

Apparatus for use with a cutting device for cutting a strip of moving material, the combination including: first means located a predetermined distance in advance of said cutting device for producing first and second cutting command signals indicating the passage of the beginning and end of a defect in the material, respectively; output means associated with said material in advance of said cutting device for producing output signals for specified lengths of travel of the material; means connected to said output means and responsive to the first cutting command signal from said first means indicating the beginning of a defect to produce a first actuating signal to said cutting device after the material has traveled a first predetermined distance from the occurence of said first cutting command signal; further means connected to said output means and responsive to the second cutting command signal from said first means indicating the end of the defect to produce a second actuating signal after the material has traveled a second predetermined distance from the occurrence of said second cutting command signal; and whereby the material is cut a first predetermined distance prior to the defect and a second predetermined distance after the defect thereby to insure complete removal of the defect from the material.

Claim 23

The apparatus of claim 19 wherein said first means for producing cutting command signals comprises: a source of radiation positioned on one side of the material to sense the intensity a radiation detector positioned on the opposite side of the material of the radiation transmitted therethrough; means providing a reference; and means comparing said reference level to the actual intensity of the radiation transmitted through the material thereby to produce cutting command signals when a defect passes between said radiation source and said radiation detector.

Claim 24

The apparatus of claim 19 wherein said first means for producing cutting command signals includes a manually actuated switch.