US4803875A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for determining the flow rate of a flowing medium
Assignee: Robert Bosch GmbH
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Filing: 1987-10-13
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Granted: 1989-02-14
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Expires: 2007-10-13
Abstract
Abstract An apparatus for determining the flow rate of a flowing medium having a substrate fastened at one end with a resistor arrangement disposed on the substrate which includes a layer-like measuring resistor (R S ) and a layer-like heating resistor (R H ). The heating output is regulated such that the measuring resistor (R S ) has a constant electrical resistance, representing a flow rate of the flowing medium. By suitable provisions, such as a meandering pattern for the heating resistor (R H ), the local resistance of the heating resistor (R H ) crosswise to the flow direction is made to decrease toward the fastened end. Thus, the temperature generated by means of the heating resistor (R H ) inside the substrate and the measuring resistor (R S ) decreases toward the fastened end.
Inventors
- 👤 Ulrich Kuhn
- 👤 Sybille Stumpf
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 02:35
CPC Classifications
G; G01; G01F; G01F1/00; G01F1/68; G01F1/684; G01F1/688; G01F1/69; G01F1/692
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
155 words
An apparatus for determining the flow rate of a flowing medium through a flow passage, having a substrate retained by at least one end in the flow passage by a fastening means, said substrate having a leading edge and a trailing edge, a layer-like, temperature-dependent measuring resistor as well as a layer-like heating resistor located on said substrate and spaced from said fastening means, a resistor detection device which regulates a heat output of said heating resistor as a function of the flow rate of the flowing medium, said heating resistor and said measuring resistor being disposed on said substrate in an electrically insulated manner, said heating resistor (R H ) extends farther toward said fastening means (21) from an end opposite from said fastening means than said measuring resistor (R S ) and the resistance value per unit of surface area of the heating resistor (R H ) decreases toward the fastening means (21).
Claim 2
Independent Claim
155 words
An apparatus for determining the flow rate of a flowing medium through a flow passage, having a substrate retained by at least one end in the flow passage by a fastening means, said substrate having a leading edge and a trailing edge, a layer-like, temperature-dependent measuring resistor as well as a layer-like heating resistor located on said substrate and spaced from said fastening means, a resistor detection device which regulates a heat output of said heating resistor as a function of the flow rate of the flowing medium, said heating resistor and said measuring resistor being disposed on said substrate in an electrically insulated manner, said heating resistor (R H ) extends farther toward said fastening means (21) from an end opposite from said fastening means than said measuring resistor (R S ) and the resistance value per unit of surface area of the heating resistor (R H ) decreases toward the fastening means (21).
Claim 3
Dependent Claim
33 words
An apparatus as defined by claim 1, in which said heating resistor (R H ) is divided into individual resistor tracks (45) having a cross-sectional area that increases toward the fastening means (21).
Claim 4
Dependent Claim
20 words
An apparatus as defined by claim 2, wherein said resistor tracks (45) extend in the flow direction of the medium.
Claim 5
Dependent Claim
21 words
An apparatus as defined by claim 2, wherein said resistor tracks (45) extend crosswise to the flow direction of the medium.
Claim 6
Dependent Claim
20 words
An apparatus as defined by claim 1, wherein said heating resistor (R H ) comprises at least two resistor layers.
Claim 7
Dependent Claim
22 words
An apparatus as defined by claim 5, wherein said at least two resistor layers are located in one plane adjacent one another.
Claim 8
Dependent Claim
23 words
An apparatus as defined by claim 5, wherein said at least two resistor layers are disposed in planes layered one above the other.
Claim 9
Dependent Claim
45 words
An apparatus as defined by claim 1, in which said heating resistor (R H ) and said measuring resistor (R S ) are located downstream of a slit (25) made in the substrate (20) crosswise to the flow direction and toward the fastening means (21).
Claim 10
Dependent Claim
45 words
An apparatus as defined by claim 2, in which said heating resistor (R S ) and said measuring resistor (R S ) are located downstream of a slit (25) made in the substrate (20) crosswise to the flow direction and toward the fastening means (21).
Claim 11
Dependent Claim
45 words
An apparatus as defined by claim 3, in which said heating resistor (R S ) and said measuring resistor (R S ) are located downstream of a slit (25) made in the substrate (20) crosswise to the flow direction and toward the fastening means (21).
Claim 12
Dependent Claim
45 words
An apparatus as defined by claim 4, in which said heating resistor (R S ) and said measuring resistor (R S ) are located downstream of a slit (25) made in the substrate (20) crosswise to the flow direction and toward the fastening means (21).
Claim 13
Dependent Claim
45 words
An apparatus as defined by claim 5, in which said heating resistor (R S ) and said measuring resistor (R S ) are located downstream of a slit (25) made in the substrate (20) crosswise to the flow direction and toward the fastening means (21).
Claim 14
Dependent Claim
45 words
An apparatus as defined by claim 6, in which said heating resistor (R S ) and said measuring resistor (R S ) are located downstream of a slit (25) made in the substrate (20) crosswise to the flow direction and toward the fastening means (21).
Claim 15
Dependent Claim
45 words
An apparatus as defined by claim 7, in which said heating resistor (R H ) and said measuring resistor (R S ) are located downstream of a slit (25) made in the substrate (20) crosswise to the flow direction and toward the fastening means (21).
Claim 16
Dependent Claim
27 words
An apparatus as defined by claim 8, in which said slit (25) extends farther toward the fastening means (21) than does the heating resistor (R H ).
Claim 17
Dependent Claim
27 words
An apparatus as defined by claim 9, in which said slit (25) extends farther toward the fastening means (21) than does the heating resistor (R H ).
Claim 18
Dependent Claim
27 words
An apparatus as defined by claim 10, in which said slit (25) extends farther toward the fastening means (21) than does the heating resistor (R H ).
Claim 19
Dependent Claim
27 words
An apparatus as defined by claim 11, in which said slit (25) extends farther toward the fastening means (21) than does the heating resistor (R H ).
Claim 20
Dependent Claim
27 words
An apparatus as defined by claim 12, in which said slit (25) extends farther toward the fastening means (21) than does the heating resistor (R H ).
Claim 21
Dependent Claim
27 words
An apparatus as defined by claim 13, in which said slit (25) extends farther toward the fastening means (21) than does the heating resistor (R H ).
Claim 22
Dependent Claim
27 words
An apparatus as defined by claim 14, in which said slit (25) extends farther toward the fastening means (21) than does the heating resistor (R H ).
Claim 23
Dependent Claim
22 words
An apparatus as defined by claim 8, in which a further resistor (R K ) is located upstream of the slit (25).
Claim 24
Dependent Claim
22 words
An apparatus as defined by claim 15, in which a further resistor (R K ) is located upstream of the slit (25).
References Cited (Backward Citations)
US4399697A
Cited
US4449402A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-02-14 | 1992-08-15 | 1993-02-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-02-14 | 1996-08-15 | 1997-02-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-02-14 | 2000-08-15 | 2001-02-14 | $7700.00 | Window Closed / Lapsed |