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US3787930A Expired / Lapsed US ⏱️ 0.0 years remaining

Process for randomizing card webs

Assignee: Fiber Technology Corp
•
Filing: 1971-08-12
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Granted: 1974-01-29
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Expires: 1991-08-12
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Abstract

Abstract The generally parallelized orientation of fibers being removed from the doffer of a card is randomized by withdrawing the web of fibers by means of a pair of conveyor belts and a vacuum slot situated adjacent to the rotating doffer surface.

Inventors

  • 👤 G Allen

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-30 13:05
CPC Classifications
D; D01; D01G; D01G15/00; D01G15/02; D01G15/12; D01G15/46; D01G15/465

Claims Analysis

Total Claims: 3
Claim 1
Independent Claim 214 words
A process for rearranging the orientation of fibers in a web which comprises: carrying a web of fibers on a moving cylindrical surface having a multiplicity of teeth, retaining said web on said surface until it reaches a doffing zone, withdrawing air by a vacuum slot from said doffing zone through a moving air-permeable conveyor positioned less than an average fiber length from said moving surface, creating an onrush of air from various directions and guiding said air into a stream from above said doffing zone to impinge upon said web while said web is in said doffing zone, thereby creating a turbulent zone therein that causes said web to abruptly change direction and causes at least the trailing ends of a substantial number of fibers of said web to become bent, buckled, and distorted into random arRangement, withdrawing said air stream through said vacuum slot while substantially blocking air from entering said doffing zone from directions opposed to said air stream, said web being doffed from said moving surface in said doffing zone by the vacuum in said vacuum slot, and, depositing said randomized web on said moving air-permeable conveyor, said conveyor moving at a linear speed which is at least 20 percent less than the linear speed of said moving cylindrical surface.
Claim 2
Dependent Claim 214 words
A process for rearranging the orientation of fibers in a web which comprises: carrying a web of fibers on a moving cylindrical surface having a multiplicity of teeth, retaining said web on said surface until it reaches a doffing zone, withdrawing air by a vacuum slot from said doffing zone through a moving air-permeable conveyor positioned less than an average fiber length from said moving surface, creating an onrush of air from various directions and guiding said air into a stream from above said doffing zone to impinge upon said web while said web is in said doffing zone, thereby creating a turbulent zone therein that causes said web to abruptly change direction and causes at least the trailing ends of a substantial number of fibers of said web to become bent, buckled, and distorted into random arRangement, withdrawing said air stream through said vacuum slot while substantially blocking air from entering said doffing zone from directions opposed to said air stream, said web being doffed from said moving surface in said doffing zone by the vacuum in said vacuum slot, and, depositing said randomized web on said moving air-permeable conveyor, said conveyor moving at a linear speed which is at least 20 percent less than the linear speed of said moving cylindrical surface.
Claim 3
Dependent Claim 31 words
The process according to claim 1 wherein the linear speed of said air-permeable conveyor is between 50 percent and 83 percent of the linear surface speed of said moving cylindrical surface.

References Cited (Backward Citations)

GB962162A Cited
US3256569A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1977-01-28 1977-07-30 1978-01-29 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1981-01-28 1981-07-30 1982-01-29 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1985-01-28 1985-07-30 1986-01-29 $7700.00 Window Closed / Lapsed

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