US3828248A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for measuring a predetermined characteristic of moving sheet material which accommodates both tilting and changes in thickness and vertical location of the material
Assignee: Individual
•
Filing: 1972-04-21
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Granted: 1974-08-06
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Expires: 1992-04-21
Abstract
Abstract Apparatus for sensing the thickness of sheet materials such as paper is in the form of a gauge having opposed rubber diaphrams which are actuated into mutual engagement with the moving sheet material by associated air pumps. Mounted on the diaphragms are magnetic circuit means which include a ferrite core and an inductive coil whose inductance is affected by the gap caused by the paper which is part of the magnetic flux path. The coil of the ferrite core is coupled to an oscillator whereby the resonant frequency of the oscillator indicates the gap distance and thus, the thickness of the sheet material.
Inventors
- 👤 G Wennerberg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 13:46
CPC Classifications
G; G01; G01B; G01B7/00; G01B7/02; G01B7/06; G01B7/10; G01B7/107
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
164 words
Apparatus for sensing the thickness of moving sheet material comprising: first and second air chambers having first and second major apertures respectively; first and second flexible sheet means each having at least one corrugation and closing said first and second apertures respectively said sheet means being juxtaposed to provide a gap therebetween in which said sheet material may be inserted; magnetic circuit means mounted on said first and second sheet means to provide a magnetic flux across said gap; air supply means for providing a pressure in said chambers greater than ambient pressure to tend to cause said first and second flexible sheet means to move toward one another and to cause said magnetic circuit means to move into mutual engagement with said moving sheet material whereby the length of the flux path across said gap is modified in accordance with the thickness of said sheet material and said flexible sheet means in cooperation with their corrugations accommodate tilting of said moving sheet material.
Claim 2
Dependent Claim
164 words
Apparatus for sensing the thickness of moving sheet material comprising: first and second air chambers having first and second major apertures respectively; first and second flexible sheet means each having at least one corrugation and closing said first and second apertures respectively said sheet means being juxtaposed to provide a gap therebetween in which said sheet material may be inserted; magnetic circuit means mounted on said first and second sheet means to provide a magnetic flux across said gap; air supply means for providing a pressure in said chambers greater than ambient pressure to tend to cause said first and second flexible sheet means to move toward one another and to cause said magnetic circuit means to move into mutual engagement with said moving sheet material whereby the length of the flux path across said gap is modified in accordance with the thickness of said sheet material and said flexible sheet means in cooperation with their corrugations accommodate tilting of said moving sheet material.
Claim 3
Dependent Claim
82 words
Apparatus as in claim 1 where said magnetic circuit includes a U-shaped core of magnetic material, winding means on the core, bearing shoe means fastened to said first sheet means having apertures through which the legs of the core extend, said shoe means consisting of a highly wear-resistant dimensionally stable material, said magnetic circuit also including a disc of magnetic material mounted on said second sheet means whereby a flux path is completed between said legs througH said disc and said gap.
Claim 4
Dependent Claim
38 words
Apparatus as in claim 2 where one of said legs is fixed in said shoe aperture by a relatively rigid adhesive and the other of said legs is fixed in said shoe aperture by a rubber type adhesive.
Claim 5
Dependent Claim
13 words
Apparatus as in claim 2 where said shoe means consists of ruby material.
Claim 6
Dependent Claim
49 words
Apparatus as in claim 1 together with two bearing rings of relatively rigid material affixed respectively to said first and second sheet means for bearing against said sheet material said rings lying in substantially the same plane as the portions of said magnetic circuit means engaging said sheet material.
Claim 7
Dependent Claim
38 words
Apparatus as in claim 1 where each of said chambers has an additional aperture together with means for coupling said aperture to ambient atmosphere said coupling means including flexible sheet means each having at least one annular corrugation.
Claim 8
Dependent Claim
34 words
Apparatus as in claim 6 where said coupling means includes a hood surrounding each of said chambers each of said hoods including at least one flexible sheet means for communicating to said ambient atmosphere.
Claim 9
Dependent Claim
54 words
Apparatus as in claim 1 where said magnetic circuit means includes a first portion centrally mounted on said first sheet means for providing a source of magnetic flux and a second portion mounted on said second sheet means for completing a flux path from said first portion through said gap to said second portion.
Claim 10
Dependent Claim
21 words
Apparatus as in claim 8 where said second portion has a larger diameter than said first portion to compensate for misalignment.
Claim 11
Dependent Claim
28 words
Apparatus as in claim 1 together with oscillator means having a resonant frequency determined by a feedback circuit which includes a winding for driving said magnetic circuit means.
Claim 12
Dependent Claim
162 words
Apparatus for sensing the thickness of moving sheet material comprising: magnetic circuit means having a first portion for providing a source of magnetic flux and a second portion juxtaposed with said first portion to provide a gap therebetween in which said sheet material may be inserted for completing a flux path from said first portion through said gap to said second portion;, said first portion including a member of magnetic material and a bearing shoe having a planar surface for engaging said moving sheet material, the end of said member extending through said shoe, said second portion also including a bearing shoe having a planar surface for engaging the opposite side of said material and means for pivotally mounting said bearing shoes respectively with pivot points which are substantially in the planes of said respective planar surfaces such pivotal mounting means accommodating tilting of said moving sheet material and including first and second flexible sheet means each having at least one corrugation.
Claim 13
Dependent Claim
162 words
Apparatus for sensing the thickness of moving sheet material comprising: magnetic circuit means having a first portion for providing a source of magnetic flux and a second portion juxtaposed with said first portion to provide a gap therebetween in which said sheet material may be inserted for completing a flux path from said first portion through said gap to said second portion;, said first portion including a member of magnetic material and a bearing shoe having a planar surface for engaging said moving sheet material, the end of said member extending through said shoe, said second portion also including a bearing shoe having a planar surface for engaging the opposite side of said material and means for pivotally mounting said bearing shoes respectively with pivot points which are substantially in the planes of said respective planar surfaces such pivotal mounting means accommodating tilting of said moving sheet material and including first and second flexible sheet means each having at least one corrugation.
Claim 14
Dependent Claim
137 words
Apparatus for measuring a predetermined characteristic of moving sheet material comprising: first and second air chambers having first and second major apertures; first and second flexible sheet means each having at least one corrugation and closing said first and second apertures respectively said sheet means being juxtaposed to provide a gap therebetween in which said sheet material may be inserted; measuring means mounted on said first and second sheet means for measuring a predetermined characteristic of said sheet material; air supply means for providing a pressure in said chambers greater than ambient pressure to cause said first and second sheet means to move toward one another and to cause said measuring means to move into mutual engagement with said sheet material said flexible sheet means in cooperation with their corrugations accommodating tilting of said moving sheet material.
Claim 15
Dependent Claim
137 words
Apparatus for measuring a predetermined characteristic of moving sheet material comprising: first and second air chambers having first and second major apertures; first and second flexible sheet means each having at least one corrugation and closing said first and second apertures respectively said sheet means being juxtaposed to provide a gap therebetween in which said sheet material may be inserted; measuring means mounted on said first and second sheet means for measuring a predetermined characteristic of said sheet material; air supply means for providing a pressure in said chambers greater than ambient pressure to cause said first and second sheet means to move toward one another and to cause said measuring means to move into mutual engagement with said sheet material said flexible sheet means in cooperation with their corrugations accommodating tilting of said moving sheet material.
Claim 16
Dependent Claim
14 words
Apparatus as in claim 11 where said bearing shoes consist of dimensionally stable material.
Claim 17
Dependent Claim
102 words
Apparatus as in claim 12 where each of said flexible sheet means is circular in configuration and include a circular corrugation near the circumference of the sheet means together with a ring of rigid material located inboard of said corrugation and defininG a drumhead type portion for each of said sheet means the center of said drumhead portions of each of said sheet means having said measuring means mounted thereon and together with a plurality of bearing members of highly wear resistant material mounted on each of said drumhead portions between said ring and said center for bearing against said sheet material.
Claim 18
Dependent Claim
27 words
Apparatus as in claim 14 where each of said plurality of said bearing members are located on a circle concentric with said center of said drumhead portions.
Claim 19
Dependent Claim
13 words
Apparatus as in claim 14 where said bearing members consist of sapphire material.
Claim 20
Dependent Claim
157 words
Apparatus for sensing the thickness of moving sheet material comprising: an air chamber having a major aperture, first flexible sheet means having at least one corrugation and closing said major aperture; second sheet means juxtaposed with said first sheet means to provide a gap therebetween in which said sheet material may be inserted; magnetic circuit means mounted on said first and second sheet means to provide a magnetic flux across said gap; air supply means for providng a pressure in said chamber greater than ambient pressure to tend to cause said first flexible sheet means to move toward said second sheet means and to cause said magnetic circuit means to move into mutual engagement with said moving sheet material whereby the length of the flux path across said gap is modified in accordance with the thickness of said sheet material and said flexible sheet means in cooperation with said corrugation accommodates tilting of said moving sheet material.
Claim 21
Dependent Claim
157 words
Apparatus for sensing the thickness of moving sheet material comprising: an air chamber having a major aperture, first flexible sheet means having at least one corrugation and closing said major aperture; second sheet means juxtaposed with said first sheet means to provide a gap therebetween in which said sheet material may be inserted; magnetic circuit means mounted on said first and second sheet means to provide a magnetic flux across said gap; air supply means for providng a pressure in said chamber greater than ambient pressure to tend to cause said first flexible sheet means to move toward said second sheet means and to cause said magnetic circuit means to move into mutual engagement with said moving sheet material whereby the length of the flux path across said gap is modified in accordance with the thickness of said sheet material and said flexible sheet means in cooperation with said corrugation accommodates tilting of said moving sheet material.
Claim 22
Dependent Claim
70 words
Apparatus as in claim 12 where each of said flexible sheet means is circular in configuration and include a circular corrugation near the circumference of the sheet means together with a ring of rigid material located inboard of said corrugation and defining a drumhead type portion for each of said sheet means the center of said drumhead portions of each of said sheet means having said measuring means mounted thereon.
References Cited (Backward Citations)
SU157503A1
Cited
FR619826A
Cited
US2581394A
Cited
DE1016028B
Cited
GB1001081A
Cited
US3411075A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-08-05 | 1978-02-04 | 1978-08-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-05 | 1982-02-04 | 1982-08-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-05 | 1986-02-04 | 1986-08-06 | $7700.00 | Window Closed / Lapsed |