Material thickness detector

Claim 2

Detector apparatus for detecting thickness variations of a continuous strip of material being passed through said apparatus, comprising: a. thickness variation detecting means, for detecting thickness variations of said passing material with respect to a material thickness reference and having a cam mounted on a rotatable arm, and switch means positioned operatively adjacent to said cam, said rotatable arm being responsive to the thickness of said passing material, said cam actuating said switch means when said thickness variations are detected, said detector sensitivity being a function of the shape of said cam and the position of said cam on said rotatable arm; b. automatic thickness reference adjusting means to adjust said material thickness reference to correspond to any thickness of said passing material which is uniform for at least a predetermined length, said detecting means and said reference adjusting means cooperating to provide a thickness detection sensitivity which is substantially constant for varying thicknesses and substantially independent with respect to said thickness reference; and c. signal generating means actuated by said thickness variation detecting means for generating electrical signals in response to detected thickness variations, and material operating means connected to and responsive to said signals for operating on said passing material.

Claim 3

The apparatus as described in claim 1, wherein said rotatable arm is substantially normal with respect to said passing material when said passing material is uniform in thickness, and said switch means comprises a pair of switches positioned symmetrically with respect to said arm when in said normal positon.

Claim 4

The apparatus as described in claim 2 comprising a movable detector roller leg to which said rotatable arm is integrally connected, and comprising a stationary detector roller leg, said movable roller leg being pivotable with respect to said stationary roller leg at a pivot point common to said two legs.

Claim 5

The appaRatus as described in claim 3, wherein said automatic thickness reference adjusting means comprises a slider block, a gib positioned contiguous to said slider block and normally maintained in frictional contact therewith, said pivot point being integrally connected to said slider block.

Claim 6

The apparatus as described in claim 4 wherein said stationary detector leg is non-rotatable with respect to said pivot point, and exerts a force on said pivot point in response to changes in thickness of said passing material, which force tends to force said pivot point up or down in response to upward or downward variation in said thickness.

Claim 7

The apparatus as described in claim 5 comprising a cam arm normally bearing upon said gib, and a solenoid operatively connected to said signal generating means to hold said arm so as to normally maintain said gib in frictional contact with said slider block when no thickness variation is sensed, and to release said arm so that said slider block is free to move in response to the force of said movable detector leg when a thickness variation over said predetermined length is detected, thereby permitting adjustment of said pivot point and corresponding adjustment of said thickness reference.

Claim 8

The apparatus as described in claim 6 comprising delay means operatively connected to said signal generating means, and connected to said material operating means so as to cause said passing material to be operated upon at a given time delay after a thickness variation is detected.

Claim 9

The apparatus as described in claim 7, wherein said material is a continuous strip of belt loop material, and wherein said operating means comprises a cutter for cutting predetermined loop lengths of said material, and reject means controlled from said delay means for rejecting any such predetermined loop lengths having detected thickness variations.

Claim 10

The apparatus as described in claim 6, wherein said movable detector roller leg and said stationary detector roller leg are carried by and connected to a movable detector roller and stationary detector roller respectively, said rollers being spaced apart by said predetermined length.

Claim 11

Detector apparatus for detecting relative thickness variations of a continuous strip of material being passed through said apparatus, comprising: a. movable detector means in contact with said passing material and responsive to the thickness of said material at a first position; b. stationary detector means positioned in contact with said passing material and positioned at a second position spaced from said first position by at least a first predetermined length, and normally unresponsive to thickness variations of said passing material; c. a movable detector arm integrally connected to said movable detector means, said movable detector means being pivotably connected to said stationary detecting means at a pivot point; d. a cam mounted on said movable detector arm, and switch means located on respective opposite sides of said cam, said switch means being adapted to generate a signal when contacted by said cam; e. solenoid-actuated pivot point control means, connected to and responsive to said switch means, to maintain said pivot point in a normally fixed position, and to permit displacement of said pivot point upon receipt of a signal from said switch means, thereby permitting said pivot point to adjust in position responsive to the thickness of said passing material at the position of said stationary detector means; and f. the shape of said cam, the position of connection of said cam to said movable arm, and the position of said switch means with respect to said cam cooperating to provide a detection sensitivity substantially independent of the thickness of said passing material.

Claim 12

Detector apparatus for detecting relative thickness variations of a continuous strip of material being passed through said apparatus, comprising: a. movable detector means in contact with said passing material and responsive to the thickness of said material at a first position; b. stationary detector means positioned in contact with said passing material and positioned at a second position spaced from said first position by at least a first predetermined length, and normally unresponsive to thickness variations of said passing material; c. a movable detector arm integrally connected to said movable detector means, said movable detector means being pivotably connected to said stationary detecting means at a pivot point; d. a cam mounted on said movable detector arm, and switch means located on respective opposite sides of said cam, said switch means being adapted to generate a signal when contacted by said cam; e. solenoid-actuated pivot point control means, connected to and responsive to said switch means, to maintain said pivot point in a normally fixed position, and to permit displacement of said pivot point upon receipt of a signal from said switch means, thereby permitting said pivot point to adjust in position responsive to the thickness of said passing material at the position of said stationary detector means; and f. the shape of said cam, the position of connection of said cam to said movable arm, and the position of said switch means with respect to said cam cooperating to provide a detection sensitivity substantially independent of the thickness of said passing material.

Claim 13

The apparatus as described in claim 10, wherein said movable detector means comprises a movable detector leg mounted on and connected to a movable detector roller, and said stationary detector means is mounted on and connected to a stationary detector roller.

Claim 14

The apparatus as described in claim 11, wherein said pivot point control means comprises a slider block, a gib positioned contiguous to said slider block and normally maintained in frictional contact therewith, said pivot point being integrally connected to said slider block, a normally energized solenoid connecting to said switch means, and a solenoid arm operatively controlled by said solenoid and normally engaging said gib, said switch means causing de-energization of the solenoid and release of the gib from frictional contact with said slider block when said cam contacts said switch means, thereby allowing free movement of the slider block and adjustment of the pivot point to a new position.

Claim 15

The apparatus as described in claim 12, comprising cutting means for cutting said continuous strip of material into predetermined lengths after same has been passed by said rollers, reject means for rejecting any of said cut lengths having a detected thickness variation in excess of a predetermined detection level, and time-delay circuitry connected to said switch means and operatively connected to said reject means, for actuating said reject means a predetermined time period after detection of said any cut lengths.

Claim 16

The apparatus as described in claim 13, wherein said predetermined length is greater than the length between said movable detector roller and said stationary detector roller.

Claim 17

The apparatus as described by claim 10, wherein said switch means comprises a pair of switches, each switch located on a respective opposite side of said cam, said switches being pivotably mounted and adapted to have an override property such that each such switch moves in the direction of the movement of said cam when said cam moves a distance further than that required to make contact with such switch.

Claim 18

The apparatus as described in claim 10, wherein said movable arm is normally held substantially perpendicular to the passing strip of material, the stationary leg is aligned axially with said movable arm when in said normally perpendicular position and is held non-rotatable about said pivot point; said stationary leg has a first movable portion responsive to the thickness of said passing material and a second portion non-rotatably connected to said pivot point, said first portion being movable within a cavity in said second portion and being restrained from movement therein by a spring, which spring exerts a force on said pivot point in response to thickness variations of said passing material.

Claim 19

The apparatus as described in claim 10, wherein said cam has a cam surface with switch-contacting segments spaced symmetrically with respect to said movable detector arm, and said switch means comprises a pair of switches, each switch being located on a respective side of said cam, and equidistant from respective cam surface segments when the portion of said passing material being detected is uniform in thickness.

Claim 20

Apparatus for cutting short fixed lengths of material from a continuously moving strip of material fed through said apparatus, and for collecting such lengths having thickness variations within a predetermined detection level and rejecting any such lengths having thickness variations equal to or in excess of such detection level, comprising: a. movable detector means in contact with said passing material and responsive to the thickness of said material at a first position; b. stationary detector means positioned in contact with said passing material and positioned at a second position spaced from said first position by at least a first predetermined length, and normally unresponsive to thickness variations of said passing material; c. a movable detector arm integrally connected to said movable detector means, said movable detector means being pivotably connected to said stationary detecting means at a pivot point; d. a cam mounted on said movable detector arm, and switch means located on respective opposite sides of said cam, said switch means being adapted to generate a signal when contacted by said cam; e. solenoid-actuated pivot point control means, connected to and responsive to said switch means, to maintain said pivot point in a normally fixed position, and to permit displacement of said pivot point upon receipt of a signal from said switch means, thereby permitting said pivot point to adjust in position responsive to the thickness of said passing material at the position of said stationary detector means; f. cutting means, positioned in registry with the path of said passing length of material after it has passed said movable detector means and stationary detector means, for cutting said passing material into said short lengths; g. reject means, for capturing said any such short lengths; and h. electronic control means, operatively coupling said switch means with said reject means, to control rejection of said any such short lengths.

Claim 21

Apparatus for cutting short fixed lengths of material from a continuously moving strip of material fed through said apparatus, and for collecting such lengths having thickness variations within a predetermined detection level and rejecting any such lengths having thickness variations equal to or in excess of such detection level, comprising: a. movable detector means in contact with said passing material and responsive to the thickness of said material at a first position; b. stationary detector means positioned in contact with said passing material and positioned at a second position spaced from said first position by at least a first predetermined length, and normally unresponsive to thickness variations of said passing material; c. a movable detector arm integrally connected to said movable detector means, said movable detector means being pivotably connected to said stationary detecting means at a pivot point; d. a cam mounted on said movable detector arm, and switch means located on respective opposite sides of said cam, said switch means being adapted to generate a signal when contacted by said cam; e. solenoid-actuated pivot point control means, connected to and responsive to said switch means, to maintain said pivot point in a normally fixed position, and to permit displacement of said pivot point upon receipt of a signal from said switch means, thereby permitting said pivot point to adjust in position responsive to the thickness of said passing material at the position of said stationary detector means; f. cutting means, positioned in registry with the path of said passing length of material after it has passed said movable detector means and stationary detector means, for cutting said passing material into said short lengths; g. reject means, for capturing said any such short lengths; and h. electronic control means, operatively coupling said switch means with said reject means, to control rejection of said any such short lengths.

Claim 22

The apparatus as described in claim 18, wherein said material comprises sewn fabric material.

Claim 23

The apparatus as described in claim 1, wherein said cam slope is asymmetrical.

Claim 24

The apparatus as described in claim 1, wherein said switch means comprises a pair of switches positioned asymmetrically with respect to said arm when in said normal position.

Claim 25

Detector apparatus for detecting thickness variations of a continuous strip of material being passed through said apparatus, comprising: a. thickness variation detecting means, for detecting thickness variations of said passing material with respect to a material thickness reference and having a cam mounted on a rotatable arm, and switch means positioned operatively adjacent to said cam, said rotatable arm being responsive to the thickness of said passing material, said cam actuating said switch means when said thickness variations are detected, said detector sensitivity being a function of the shape of said cam and the position of said cam on said rotatable arm; and, b. automatic thickness reference adjusting means to adjust said material thickness reference to correspond to any thickness of said passing material which is uniform for at least a predetermined length.

Claim 26

Detector apparatus for detecting thickness variations of a continuous strip of material being passed through said apparatus, comprising: a. thickness variation detecting means, for detecting thickness variations of said passing material with respect to a material thickness reference and having a cam mounted on a rotatable arm, and switch means positioned operatively adjacent to said cam, said rotatable arm being responsive to the thickness of said passing material, said cam actuating said switch means when said thickness variations are detected, said detector sensitivity being a function of the shape of said cam and the position of said cam on said rotatable arm; and, b. automatic thickness reference adjusting means to adjust said material thickness reference to correspond to any thickness of said passing material which is uniform for at least a predetermined length.

Claim 27

The apparatus as described in claim 22 wherein said detecting means and said reference adjusting means cooperate to provide a thickness detection sensitivity which is substantially constant for varying thicknesses and substantially independent with respect to said thickness reference.

Claim 28

The apparatus as described in claim 23 comprising signal generating means actuated by said thickness variation detecting means for generating electrical signals in response to detected thickness variations, and material operating means connected to and responsive to said signals for operating on said passing material.