US5128076A — Apparatus and method for producing an elongate st…

Claim 1

Independent Claim 270 words

An apparatus for producing an elongate strip of material comprising: an extrusion die for continuously extruding a flowable material in a downline direction to form a tube with a generally cylindrical central longitudinal cavity; tube pressurizing means for controlling tube volume in the central longitudinal cavity of the tube to expand the tube laterally outwardly and control the diameter of the tube; means for controlling the diameter of the tube located to cause the tube to reach its final size before solidifying within the controlling means; a transport mechanism for engaging and pulling the tube in the downline direction without distorting or closing the tube, while allowing access to the central longitudinal cavity of the tube from the downline side of the tube, the transport mechanism including a plurality of drive rollers which engage the tube on only the outside of the tube to pull to the tube downline without contacting the inside of the tube; tube cutting means downline of the transport mechanism for cutting the tube into a continuous elongate strip and thereby defining an open end of the central longitudinal cavity of the tube, wherein the tube cutting means is offset at an angle with respect to the downline direction, and wherein the tube remains open and in tube form until the tube is cut; and a fluid seal for substantially sealing the cavity of the tube to control the escape of pressurizing fluid from the open end of the cavity, wherein a portion of the central longitudinal cavity extends downline of the fluid seal, and the tube cutting means is positioned downline of the fluid seal.

Claim 2

Independent Claim 270 words

An apparatus for producing an elongate strip of material comprising: an extrusion die for continuously extruding a flowable material in a downline direction to form a tube with a generally cylindrical central longitudinal cavity; tube pressurizing means for controlling tube volume in the central longitudinal cavity of the tube to expand the tube laterally outwardly and control the diameter of the tube; means for controlling the diameter of the tube located to cause the tube to reach its final size before solidifying within the controlling means; a transport mechanism for engaging and pulling the tube in the downline direction without distorting or closing the tube, while allowing access to the central longitudinal cavity of the tube from the downline side of the tube, the transport mechanism including a plurality of drive rollers which engage the tube on only the outside of the tube to pull to the tube downline without contacting the inside of the tube; tube cutting means downline of the transport mechanism for cutting the tube into a continuous elongate strip and thereby defining an open end of the central longitudinal cavity of the tube, wherein the tube cutting means is offset at an angle with respect to the downline direction, and wherein the tube remains open and in tube form until the tube is cut; and a fluid seal for substantially sealing the cavity of the tube to control the escape of pressurizing fluid from the open end of the cavity, wherein a portion of the central longitudinal cavity extends downline of the fluid seal, and the tube cutting means is positioned downline of the fluid seal.

Claim 3

Dependent Claim 13 words

The apparatus of claim 1 wherein the transport mechanism comprises four drive rollers.

Claim 4

Dependent Claim 43 words

The apparatus of claim 1 further comprising means for providing relative rotation between the tube and the tube cutting means such that the tube cutting means cuts the tube into a substantially continuous web of a desired width as the tube moves downline.

Claim 5

Dependent Claim 35 words

The apparatus of claim 3 wherein the relative rotation providing means provides relative rotation between (a) the tube cutting means and (b) the extrusion die and transport mechanism which rotate together to rotate the tube.

Claim 6

Dependent Claim 34 words

The apparatus of claim 4 further comprising a controller for controlling the rotational velocity of the extrusion die, the transport mechanism, and the tube cutting means to affect the width of the elongate strip.

Claim 7

Dependent Claim 50 words

The apparatus of claim 1 wherein the tube cutting means comprises a blade positioned downline of the fluid seal and outside of the tube, and nip rolls adjacent the blade which constrain and drive the material of the tube while cutting the tube into an elongate strip with the blade.

Claim 8

Dependent Claim 11 words

The apparatus of claim 1 wherein the pressurizing fluid is air.

Claim 9

Dependent Claim 105 words

The apparatus of claim 7 wherein the controlling means comprises a constraining structure located between the extrusion die and the transport mechanism which controls expansion of the tube to a desired outer diameter range after the tube is formed by the extrusion die, the constraining structure comprising: a casing positioned downline of the extrusion die; a sleeve in the casing having an interior passageway with at least a portion having a constant cross-sectional shape and constant circumference adapted to receive the tube to permit movement of the tube along its longitudinal axis in the downline direction, the casing and the sleeve having low friction walls.

Claim 10

Dependent Claim 24 words

The apparatus of claim 8 wherein the sleeve is annular and the passageway is centrally located within the annular sleeve and is generally cylindrical.

Claim 11

Dependent Claim 152 words

The apparatus of claim 9 wherein the casing and the sleeve walls define a gas chamber separate from the passageway; and the constraining structure further comprises a gas inlet for providing pressurized gas to the gas chamber from a source of pressurized gas; wherein the sleeve has a sufficiently large porosity which permits gas to pass through the sleeve from the gas chamber to the passageway, the gas forming a gas layer along the inner surface of the sleeve at a sufficiently large pressure to constrain the tube to the desired outer diameter while the tube solidifies and to prevent the tube from contacting the sleeve, and the sleeve has a sufficiently low porosity that the gas pressure increases adjacent portions of the tube which expand toward the sleeve to restrict gas flow to force the tube laterally inwardly and away from the sleeve to stabilize the tube within the central passageway.

Claim 12

Dependent Claim 62 words

The apparatus of claim 9 further comprising tube sensing means for sensing a portion of the tube before the tube enters the passageway and for providing a signal to the tube pressurizing means for pressurizing the tube to adjust the air volume inside the tube to adjust the tube diameter when the sensed portion of the tube varies from the desired range.

Claim 13

Dependent Claim 121 words

The apparatus of claim 11 wherein the tube sensing means comprises: first optical sensing means for sensing a portion of the tube when the outer diameter of the tube entering the passageway is larger than a first predetermined size and for providing a feedback signal to the tube pressurizing means when the outer diameter is larger than the first predetermined size; and second optical sensing means for sensing a portion of the tube when the outer diameter of the tube entering the passageway is smaller than a second predetermined size smaller than the first predetermined size and for providing a feedback signal to the tube pressurizing means when the outer diameter of the tube is smaller than the second predetermined size.

Claim 14

Dependent Claim 77 words

The apparatus of claim 9 further comprising positioning means for adjustably mounting the constraining structure relative to the extrusion die such that the constraining structure can be adjustably positioned within a predetermined range in the upline or downline directions so that the tube solidifies within the passageway of the casing, the sleeve having a length generally parallel to the central longitudinal axis of the passageway of between one half and three times the diameter of the passageway.

Claim 15

Independent Claim 194 words

A method of producing an elongate strip of material comprising the steps of: extruding flowable material through an annular die orifice in a downline direction to form an open-ended tube with a generally cylindrical central longitudinal cavity; pressurizing the central longitudinal cavity of the tube with a fluid to expand the tube laterally outwardly to an outer diameter within a predetermined range; transporting the tube downline with a transport mechanism by engaging the tube on only the outside of the tube to pull to the tube downline without contacting the inside of the tube, distorting the tube, or closing the tube, while allowing access to the central longitudinal cavity of the tube from the downline side of the tube; constraining the tube to control the diameter of the tube and cause the tube to reach its final size before solidifying while being constrained; cutting the tube with a cutter into a continuous elongate strip at the open end at an angle offset from the downline direction, wherein the tube remains open and in tube form until the tube is cut; and preventing escape of the pressurizing fluid through the open end of the cavity.

Claim 16

Independent Claim 194 words

A method of producing an elongate strip of material comprising the steps of: extruding flowable material through an annular die orifice in a downline direction to form an open-ended tube with a generally cylindrical central longitudinal cavity; pressurizing the central longitudinal cavity of the tube with a fluid to expand the tube laterally outwardly to an outer diameter within a predetermined range; transporting the tube downline with a transport mechanism by engaging the tube on only the outside of the tube to pull to the tube downline without contacting the inside of the tube, distorting the tube, or closing the tube, while allowing access to the central longitudinal cavity of the tube from the downline side of the tube; constraining the tube to control the diameter of the tube and cause the tube to reach its final size before solidifying while being constrained; cutting the tube with a cutter into a continuous elongate strip at the open end at an angle offset from the downline direction, wherein the tube remains open and in tube form until the tube is cut; and preventing escape of the pressurizing fluid through the open end of the cavity.

Claim 17

Dependent Claim 39 words

The method of claim 14 further comprising the step of providing relative rotation between the tube and the cutter such that the cutter cuts the tube into a continuous strip of a desired width as the tube moves downline.

Claim 18

Dependent Claim 29 words

The method of claim 15 wherein the step of providing relative rotation comprises rotating the extrusion die and transport mechanism together to rotate the tube relative to the cutter.

Claim 19

Dependent Claim 33 words

The method of claim 15 further comprising the step of controlling the rotational velocity of the the extrusion die, the transport mechanism, and the cutter to vary the width of the elongate strip

Claim 20

Dependent Claim 12 words

The method of claim 14 wherein the tube is pressurized with air.

Claim 21

Dependent Claim 43 words

The method of claim 18 wherein the constraining step comprises moving the tube in the downline direction through an annular sleeve such that the tube solidifies within the sleeve which provides a restraint such that the outer diameter is within the desired range.

Claim 22

Dependent Claim 178 words

The method of claim 19 wherein the annular sleeve is microporous and includes a central passageway, and the method further comprises the steps of: forcing pressurized gas through the microporous sleeve into the central passageway to form a thin layer of gas at a higher pressure than ambient air along the microporous sleeve; and constraining the portion of the tube within the passageway with the thin layer of gas, wherein the sleeve has a sufficiently large porosity which permits gas to pass through the sleeve from the gas chamber to the passageway, the gas forming a gas layer along the inner surface of the sleeve at a sufficiently large pressure to constrain the tube to the desired outer diameter while the tube solidifies and to prevent the tube from contacting the sleeve, and the sleeve has a sufficiently low porosity that the gas pressure increases adjacent portions of the tube which expand toward the sleeve to restrict gas flow to force the tube laterally inwardly and away from the sleeve to stabilize the tube within the central passageway.

Claim 23

Dependent Claim 52 words

The method of claim 20 further comprising the step of sensing a portion of the tube before the tube enters the passageway and providing a signal to adjust the gas volume inside the tube to expand or contract the tube when the sensed portion of the tube varies from the desired range.

Claim 24

Dependent Claim 123 words

The method of claim 21 wherein the step of sensing a portion of the tube comprises the steps of: optically sensing a portion of the tube when the outer diameter of the tube entering the passageway is larger than a first predetermined size and providing a feedback signal to lower air volume within the tube when the outer diameter is larger than the first predetermined size; and optically sensing a portion of the tube when the outer diameter of the tube entering the passageway is smaller than a second predetermined size smaller than the first predetermined size and providing a feedback signal to increase air volume within the tube when the outer diameter of the tube is smaller than the second predetermined size.

Claim 25

Dependent Claim 28 words

The method of claim 19 further comprising the step of positioning the annular sleeve relative to the extrusion die such that the tube material solidifies within the passageway.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1995-07-07	1996-01-06	1996-07-07	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1999-07-07	2000-01-06	2000-07-07	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2003-07-07	2004-01-06	2004-07-07	$7700.00	Window Closed / Lapsed

Apparatus and method for producing an elongate strip of material

Abstract

Inventors

Bibliographic Details

Claims Analysis

References Cited (Backward Citations)

USPTO Annuity & Maintenance Windows

Assigned Categories & Tags

Assign Category Tag