Patent US4508612A successfully refreshed from Google Patents.
US7078631B2
Expired / Lapsed
US
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Spring scale
Assignee: SINTEF Elektronikk OG Kybernetikk
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Filing: 2003-02-24
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Granted: 2006-07-18
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Expires: 2023-02-24
Abstract
Abstract A spring scale, in particular for weighing loads in the μg-mg range, comprises a load platform suspended by at least three flexural springs in a surrounding frame, and has bridge-connected strain gauges arranged for measuring strain on one side of the flexural springs. The flexural springs extend in succession along substantially the whole periphery of the load platform in a gap between the load platform and the inner edge of the frame, and an attachment spot on the load platform for every flexural spring is arranged substantially directly opposite or past an attachment spot on the inner edge of the frame for a next flexural spring in the succession of springs. Preferably, the spring scale is made in one piece, and manufactured by means of semiconductor process technology.
Inventors
- 👤 Dag T. Wang
- 👤 Ralph W. Bernstein
- 👤 Geir Uri Jensen
- 👤 Eivind Lund
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 19:49
CPC Classifications
G; G01; G01G; G01G3/00; G01G3/12; G01G3/14; G01G3/1402
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
96 words
A spring micro-scale, comprising a load platform suspended, by at least three flexural springs, in a surrounding frame, and with bridge-connected strain gauges arranged for measuring strain on one side of said flexural springs, said flexural springs extending in succession along substantially the whole periphery of the load platform in a gap between the load platform for each respective flexural spring being arranged substantially directly opposite or past an attachment spot on the inner edge of the frame for a next flexural spring in the succession, and said load platform being thinner than said surrounding frame.
Claim 2
Dependent Claim
96 words
A spring micro-scale, comprising a load platform suspended, by at least three flexural springs, in a surrounding frame, and with bridge-connected strain gauges arranged for measuring strain on one side of said flexural springs, said flexural springs extending in succession along substantially the whole periphery of the load platform in a gap between the load platform for each respective flexural spring being arranged substantially directly opposite or past an attachment spot on the inner edge of the frame for a next flexural spring in the succession, and said load platform being thinner than said surrounding frame.
Claim 3
Dependent Claim
30 words
The micros scale of claim 1 , wherein the strain gauges are all oriented in the same direction, to obtain insensitivity regarding positioning of an object on the load platform.
Claim 4
Dependent Claim
22 words
The micro-scale of claim 1 , wherein the flexural springs are thinned down to provide high compliance for weighing of small objects.
Claim 5
Dependent Claim
28 words
The micro-scale of claim 1 , wherein the load platform, the flexural springs and the frame are shaped as one single micro-machined or etched piece of solid matter.
Claim 6
Dependent Claim
16 words
The micro-scale of claim 4 , wherein said piece of solid matter is a silicon piece.
Claim 7
Dependent Claim
18 words
The micro-scale of claim 4 , wherein said strain gauges are integral in the piece of solid matter.
Claim 8
Dependent Claim
13 words
The micro-scale of claim 1 , wherein the strain gauges are piezo-resistive resistors.
Claim 9
Dependent Claim
29 words
The micro-scale of claim 1 , wherein each flexural spring has a strain gauge placed on a crossing between the flexural spring and the frame or the load platform.
Claim 10
Dependent Claim
13 words
The micro-scale of claim 1 , wherein the load platform is substantially quadratic.
Claim 11
Dependent Claim
20 words
The micro-scale of claim 1 , wherein the flexural springs lie parallel to respective side edges of the load platform.
Claim 12
Dependent Claim
28 words
The micro-scale of claim 9 or 10 , wherein the flexural springs have lengths substantially equal to the lengths of the closest side edges of the load platform.
Claim 13
Dependent Claim
37 words
The micro-scale of claim 1 , wherein the frame rests on, and is attached to, a substrate extending in under the load platform to work as an end stop for a swing downward of the load platform.
Claim 14
Dependent Claim
24 words
The micro-scale of claim 12 , wherein said substrate is made of glass, and is attached to the frame by means of anodic bonding.
Claim 15
Dependent Claim
53 words
The micro-scale of claim 1 , further composing a roof above the load platform, said roof being attached peripherally on the frame, with a central opening above the load platform for placing objects to be weighed, and with an additional function as an end stop for possible swings upward of the load position.
Claim 16
Dependent Claim
24 words
The micro-scale of claim 14 , wherein the roof is made of glass, and that it is attached to the frame by anodic bonding.
Claim 17
Dependent Claim
14 words
The micro-scale of claim 1 , wherein the number of flexural springs is four.
Claim 18
Dependent Claim
33 words
The micro-scale of claim 1 , wherein the mechanical structure constituted by load platform, flexural springs and frame, exhibits a four-fold rotation symmetry about a point at the center of the load platform.
Claim 19
Dependent Claim
22 words
The micro-scale of claim 1 , wherein the load platform and the inner edge of the frame have a substantially complementary shape.
Claim 20
Dependent Claim
23 words
The micro-scale of claim 12 , wherein said substrate is equipped with a central opening underneath the load platform, for inspection and cleaning.
References Cited (Backward Citations)
US4381826A
Cited
US4458770A
Cited
US4548086A
Cited
US4553436A
Cited
US4542800A
Cited
US4600066A
Cited
US4641539A
Cited
US5388460A
Cited
GB2296977A
Cited
US5814740A
Cited
US5786549A
Cited
EP1052478A2
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2009-07-17 | 2010-01-16 | 2010-07-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2013-07-17 | 2014-01-16 | 2014-07-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2017-07-17 | 2018-01-16 | 2018-07-18 | $7700.00 | Window Closed / Lapsed |