US3878619A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Drying of wool slivers
Assignee: Electricity Council
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Filing: 1972-10-25
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Granted: 1975-04-22
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Expires: 1992-10-25
Abstract
Abstract Textile fibers, for example wool slivers, are dried by passing them through a series of co-axial loop electrodes energized at a radio frequency preferably above 10 MHz to effect dielectric heating, successive electrodes along the path being at opposite polarity. The material is carried on an aportioned endless belt of resin-bonded glass fibre material. Simultaneously a stream of hot air is directed over or through the fibre material. Sensing means at the fibre outlet sense the moisture content and control the radio frequency power. A fibre break detection at the film entry switches off the radio frequency power in the event of a fibre break and also reduces the speed of traverse so that the material in the apparatus is dried by the hot air.
Inventors
- 👤 David Lowry Hodgett
- 👤 Harry Fung
- 👤 James Lawton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 23:46
CPC Classifications
D; D06; D06C; D06C7/00; D06C2700/00; D06C2700/09
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
161 words
Apparatus for drying textile fibres consisting of at least one drying section, the drying section comprising a plurality of electrodes each extending around the fibre path, a pair of bus bars to which said electrodes are connected, radio frequency supply means arranged for energising said bus bars at one end thereof at a frequency above 1 MHz, said bus bars being each connected to alternate electrodes so that alternate electrodes are of opposite polarity, an adjustable inductance connected across said bus bars at said other end, means for traversing the fibres along said path, means for directing a stream of hot air traversely through the fibres, support means for holding the fibres as they are traversed through the drying section, moisture content sensing means providing an electrical signal representative of the moisture content of the fibres leaving the apparatus, and control means responsive to said electrical signal operable to control said adjustable inductance to regulate the power applied to said electrodes.
Claim 2
Dependent Claim
161 words
Apparatus for drying textile fibres consisting of at least one drying section, the drying section comprising a plurality of electrodes each extending around the fibre path, a pair of bus bars to which said electrodes are connected, radio frequency supply means arranged for energising said bus bars at one end thereof at a frequency above 1 MHz, said bus bars being each connected to alternate electrodes so that alternate electrodes are of opposite polarity, an adjustable inductance connected across said bus bars at said other end, means for traversing the fibres along said path, means for directing a stream of hot air traversely through the fibres, support means for holding the fibres as they are traversed through the drying section, moisture content sensing means providing an electrical signal representative of the moisture content of the fibres leaving the apparatus, and control means responsive to said electrical signal operable to control said adjustable inductance to regulate the power applied to said electrodes.
Claim 3
Dependent Claim
140 words
Apparatus for drying textile fibres consisting of at least one drying section, the drying section comprising a plurality of electrodes each extending around the fibre path, radio frequency supply means arranged for energizing the electrodes at a frequency above 1 MHz with alternate electrodes of opposite polarity, means for traversing the fibres along said path from a fibre entry end, means for directing a stream of hot air transversely through the fibres, support means for holding the fibres as they are traversed through the drying section, fibre material sensing means at the drying section fibre entry, said sensing means being arranged for producing a control signal indicating the absence of fibre, and means responsive to said control signal operative to switch off the radio frequency supply means and to reduce the speed of traverse of the fibres along said path.
Claim 4
Dependent Claim
140 words
Apparatus for drying textile fibres consisting of at least one drying section, the drying section comprising a plurality of electrodes each extending around the fibre path, radio frequency supply means arranged for energizing the electrodes at a frequency above 1 MHz with alternate electrodes of opposite polarity, means for traversing the fibres along said path from a fibre entry end, means for directing a stream of hot air transversely through the fibres, support means for holding the fibres as they are traversed through the drying section, fibre material sensing means at the drying section fibre entry, said sensing means being arranged for producing a control signal indicating the absence of fibre, and means responsive to said control signal operative to switch off the radio frequency supply means and to reduce the speed of traverse of the fibres along said path.
Claim 5
Dependent Claim
159 words
Apparatus for drying textile fibres consisting of at least one drying section, the drying section comprising a plurality of loop electrodes arranged co-axially with their axis horizontal, radio frequency supply means arranged for energising the electrodes at a frequency above 1MHz with alternate electrodes of opposite polarity, a multipass transport system for carrying said fibres along a path and comprising at least one aperture belt of low dielectric loss material and having three passes extending horizontally below, through and above the electrodes, means surrounding said electrodes and transport system defining an air passageway, means for directing a stream of hot air through said air passageway, fibre material sensing means at the drying section fibre entry, said sensing means being arranged for producing a control signal indicating the absence of fibre, and means responsive to said control signal operative to switch off the radio frequency supply means and to reduce the speed of traverse of the fibres along said path.
Claim 6
Dependent Claim
159 words
Apparatus for drying textile fibres consisting of at least one drying section, the drying section comprising a plurality of loop electrodes arranged co-axially with their axis horizontal, radio frequency supply means arranged for energising the electrodes at a frequency above 1MHz with alternate electrodes of opposite polarity, a multipass transport system for carrying said fibres along a path and comprising at least one aperture belt of low dielectric loss material and having three passes extending horizontally below, through and above the electrodes, means surrounding said electrodes and transport system defining an air passageway, means for directing a stream of hot air through said air passageway, fibre material sensing means at the drying section fibre entry, said sensing means being arranged for producing a control signal indicating the absence of fibre, and means responsive to said control signal operative to switch off the radio frequency supply means and to reduce the speed of traverse of the fibres along said path.
Claim 7
Dependent Claim
159 words
Apparatus for drying textile fibres consisting of at least one drying section, the drying section comprising a plurality of loop electrodes arranged co-axially with their axis horizontal, radio frequency supply means arranged for energising the electrodes at a frequency above 1MHz with alternate electrodes of opposite polarity, a multipass transport system for carrying said fibres along a path and comprising at least one aperture belt of low dielectric loss material and having three passes extending horizontally below, through and above the electrodes, means surrounding said electrodes and transport system defining an air passageway, means for directing a stream of hot air through said air passageway, fibre material sensing means at the drying section fibre entry, said sensing means being arranged for producing a control signal indicating the absence of fibre, and means responsive to said control signal operative to switch off the radio frequency supply means and to reduce the speed of traverse of the fibres along said path.
Claim 8
Dependent Claim
159 words
Apparatus for drying textile fibres consisting of at least one drying section, the drying section comprising a plurality of loop electrodes arranged co-axially with their axis horizontal, radio frequency supply means arranged for energising the electrodes at a frequency above 1MHz with alternate electrodes of opposite polarity, a multipass transport system for carrying said fibres along a path and comprising at least one aperture belt of low dielectric loss material and having three passes extending horizontally below, through and above the electrodes, means surrounding said electrodes and transport system defining an air passageway, means for directing a stream of hot air through said air passageway, fibre material sensing means at the drying section fibre entry, said sensing means being arranged for producing a control signal indicating the absence of fibre, and means responsive to said control signal operative to switch off the radio frequency supply means and to reduce the speed of traverse of the fibres along said path.
Claim 9
Dependent Claim
27 words
Apparatus as claimed in claim 3 wherein said means surrounding said electrodes and transport system include side walls of dielectric material to form an air flow duct.
Claim 10
Dependent Claim
23 words
Apparatus as claimed in claim 3 wherein the radio frequency supply means is arranged for energising the electrodes at a frequency above 10MHz.
Claim 11
Dependent Claim
23 words
Apparatus as claimed in claim 3 wherein the air stream is directed upwardly to force the fibres against the underside of a belt.
Claim 12
Dependent Claim
17 words
Apparatus as claimed in claim 3 wherein apertured belts are Provided both above and blow the fibres.
Claim 13
Dependent Claim
28 words
Apparatus as claimed in claim 3 wherein said means for directing a stream of hot air is arranged to direct the air stream longitudinally along the fibre path.
Claim 14
Dependent Claim
28 words
Apparatus as claimed in claim 3 wherein said means for directing a stream of hot air is arranged to direct the air stream laterally across the fibre path.
Claim 15
Dependent Claim
16 words
Apparatus as claimed in claim 3 wherein the belt material is a resin-bonded glass fibres material.
Claim 16
Dependent Claim
49 words
Apparatus as claimed in claim 3 and having fibre material sensing means at the drying section fibre entry, said sensing means being arranged for producing a control signal indicating the absence of fibre, and means responsive to said control signal arranged to switch off the radio frequency supply means.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-04-21 | 1978-10-21 | 1979-04-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-21 | 1982-10-21 | 1983-04-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-21 | 1986-10-21 | 1987-04-22 | $7700.00 | Window Closed / Lapsed |