US3864625A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and a device for measuring the thickness of the wall of a tube of non-conducting material leaving an extruder nozzle
Assignee: Zumbach Electronic Automatic
•
Filing: 1972-12-12
•
Granted: 1975-02-04
•
Expires: 1992-12-12
Abstract
Abstract A method and apparatus for measuring the wall thickness of a tube of electrically non-conducting material such as one leaving an extruder, wherein at least one electrically conducting object is maintained inside the tube at a definite distance or space from the inner surface of the tube wall, and a measuring device scans the outer surface of the tube at a definite distance therefrom such that the distance between the measuring device and said object passes through a minimum, this minimum being measured and the tube thickness deduced therefrom.
Inventors
- 👤 Bruno Zumbach
- 👤 Peter Nopper
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 19:32
CPC Classifications
G; G01; G01B; G01B7/00; G01B7/02; G01B7/06; B; B29; B29C; B29C48/00; B29C48/25; B29C48/92; B29C2948/00; B29C2948/92; B29C2948/92009; B29C2948/92114; B29C2948/92152; B29C2948/92238; B29C2948/92276; B29C2948/92323; B29C2948/92447; B29C48/03; B29C48/09
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
131 words
A method of measuring the wall thickness of a tube of nonconductive material leaving an extruder nozzle, including the steps of locating an electrically conductive article inside the tube, approaching to and maintaining a measuring device at a predetermined distance from the outer surface of the tube for measurement of the distance between said article and said measuring device, providing means for producing a relative movement between said measuring device and the article such that the distance between them passes through a minimum with said article in a defined position relatively to the inner surface of the tube, detecting the value measured by said measuring device at this minimum, said value being a measure for the tube thickness where said article is located within the tube during detection of said value.
Claim 2
Independent Claim
131 words
A method of measuring the wall thickness of a tube of nonconductive material leaving an extruder nozzle, including the steps of locating an electrically conductive article inside the tube, approaching to and maintaining a measuring device at a predetermined distance from the outer surface of the tube for measurement of the distance between said article and said measuring device, providing means for producing a relative movement between said measuring device and the article such that the distance between them passes through a minimum with said article in a defined position relatively to the inner surface of the tube, detecting the value measured by said measuring device at this minimum, said value being a measure for the tube thickness where said article is located within the tube during detection of said value.
Claim 3
Dependent Claim
49 words
A method according to claim 1, wherein said article is held in contact with the inner surface of The tube along a line and the relative movement produced is such that the measuring device intersects the line of contact of the article on the inner surface of the tube.
Claim 4
Dependent Claim
24 words
A method according to claim 1, in which the measuring device is maintained near the outer surface of the tube without touching the same.
Claim 5
Dependent Claim
23 words
A method according to claim 1, wherein the article has a conductive surface which is placed against the inside surface of the tube.
Claim 6
Dependent Claim
17 words
A method according to claim 1, wherein several articles are spread around the circumference of the tube.
Claim 7
Dependent Claim
127 words
Apparatus for measuring the wall thickness of a tube of electrically insulating material leaving an extruder nozzle, comprising an electrically conducting article anchored on a mandrel forming part of an extruder nozzle, and held inside the tube being extruded, a measuring device set at a predetermined distance from the outer surface of the tube to measure the spacing between the device and the article, and means for producing relative displacement between said measuring device and said article thereby varying the distance between said article and said measuring device such that said distance becomes minimum with said article in a defined position relatively to the inner surface of the tube, said minimum distance measured by said measuring device being a measure for the thickness of the tube wall.
Claim 8
Dependent Claim
127 words
Apparatus for measuring the wall thickness of a tube of electrically insulating material leaving an extruder nozzle, comprising an electrically conducting article anchored on a mandrel forming part of an extruder nozzle, and held inside the tube being extruded, a measuring device set at a predetermined distance from the outer surface of the tube to measure the spacing between the device and the article, and means for producing relative displacement between said measuring device and said article thereby varying the distance between said article and said measuring device such that said distance becomes minimum with said article in a defined position relatively to the inner surface of the tube, said minimum distance measured by said measuring device being a measure for the thickness of the tube wall.
Claim 9
Dependent Claim
22 words
An apparatus according to claim 6, wherein said article is a flat metal spring resiliently abutting the inside wall of the tube.
Claim 10
Dependent Claim
23 words
Apparatus according to claim 7, wherein the flat spring is connected to a shaft which moves it over the circumference of the tube.
Claim 11
Dependent Claim
52 words
Apparatus according to claim 6, wherein the article is formed as a cask-shaped roller which rests against the inside surface of the tube and is rotatable about an axle at right angles to the tube axis, wherein the roller is made of non-conducting material and has a conductive part eccentrically inserted therein.
Claim 12
Dependent Claim
68 words
Apparatus according to claim 6, including a wheeled carriage resting with its wheels against the inside surface of the tube, the wheels of the carriage being coupled with a conductive plate forming said article which executes a cycloidal movement in the tube when said wheels roll off on the tube wall, including a point where it is at a minimum distance from the inside surface of the tube.
Claim 13
Dependent Claim
16 words
Apparatus according to claim 10, wherein the plate is curved towards the wall of the tube.
Claim 14
Dependent Claim
26 words
Apparatus according to claim 6, including at least one article having a cylindrical surface abutting along a longitudinal line with the inside surface of the tube.
Claim 15
Dependent Claim
15 words
Apparatus according to claim 12, wherein the article is secured to radially elastically resilient arms.
Claim 16
Dependent Claim
18 words
Apparatus according to claim 12, wherein the article is held in position by magnets located outside the tube.
Claim 17
Dependent Claim
30 words
Apparatus according to claim 6, wherein the article is a tyre-like roller metallised internally, the roller being held against the inside surface of the tube and in rolling engagement therewith.
Claim 18
Dependent Claim
53 words
Apparatus according to claim 6, wherein at least one wheel contacting the inside wall surface of the tube is mounted on said article and has its axis inclined relatively to the axis of the tube so as to produce a rotary movement of the article with respect to the circumference of the tube.
Claim 19
Dependent Claim
22 words
Apparatus according to claim 6, wherein an electromagnet is provided for temporarily holding the article against the inside surface of the tube.
Claim 20
Dependent Claim
42 words
Apparatus according to claim 6, wherein a number of electrically conducting articles are distributed along the circumference at the inside of the tube, means being provided for imparting a reciprocating rotating motion to a mesuring device for scanning over all said articles.
Claim 21
Dependent Claim
28 words
Apparatus according to claim 18, comprising switch means for slowing down the speed of the measuring device within reach of each of said articles during its scanning motion.
Claim 22
Dependent Claim
18 words
A method accordinG to claim 1, wherein several measuring devices are spread around the circumference of the tube.
Claim 23
Dependent Claim
23 words
A method according to claim 1, wherein one measuring device is moved successively to several measuring positions along the circumference of the tube.
References Cited (Backward Citations)
US2676298A
Cited
US2898550A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-02-03 | 1978-08-05 | 1979-02-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-03 | 1982-08-05 | 1983-02-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-03 | 1986-08-05 | 1987-02-04 | $7700.00 | Window Closed / Lapsed |