US5553577A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for checking the tightness of a tank venting system
Assignee: Robert Bosch GmbH
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Filing: 1994-09-30
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Granted: 1996-09-10
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Expires: 2014-09-30
Abstract
Abstract An apparatus for checking a tank venting system for leaks that serves to vent a fuel tank of a motor vehicle whose engine has a intake tube. The apparatus has an absorption filter connected to a ventilation line, which can be closed by means of a shutoff valve, and pressure producing devices for the production of an overpressure in the fuel tank. The pressure producing devices are embodied as actuatable by means of the vacuum in the intake tube in order to be able to forego the separate electromechanical drive devices for the pressure producing devices which have been necessary in the prior art.
Inventors
- 👤 Helmut Denz
- 👤 Andreas Blumenstock
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 13:16
CPC Classifications
B; B60; B60K; B60K15/00; B60K15/03; B60K15/035; B60K15/03504; F; F02; F02M; F02M25/00; F02M25/08; F02M25/0809; F02M25/0818
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
164 words
An apparatus for checking the tightness of a fuel tank venting system, which serves to vent a fuel tank of a motor vehicle having an intake tube of an engine, an absorption filter connected to a ventilation line, a shutoff valve in said ventilation line which is closed during a fuel valve tightness check, a purging line which is closed by means of a regenerating valve during a fuel tank tightness check, and at least first and second pressure control devices for A production of an overpressure in the fuel tank, said at least first and second pressure control devices using only a fluid medium within the fuel tank venting system for producing pressure during fuel tank tightness check, the at least first pressure embodied as actuatable by means of a vacuum from a vacuum source control device (18) is actuatable to control an actuatable pressure on said at least one second pressure control device (22) from a vacuum source or from atmospheric pressure.
Claim 2
Independent Claim
164 words
An apparatus for checking the tightness of a fuel tank venting system, which serves to vent a fuel tank of a motor vehicle having an intake tube of an engine, an absorption filter connected to a ventilation line, a shutoff valve in said ventilation line which is closed during a fuel valve tightness check, a purging line which is closed by means of a regenerating valve during a fuel tank tightness check, and at least first and second pressure control devices for A production of an overpressure in the fuel tank, said at least first and second pressure control devices using only a fluid medium within the fuel tank venting system for producing pressure during fuel tank tightness check, the at least first pressure embodied as actuatable by means of a vacuum from a vacuum source control device (18) is actuatable to control an actuatable pressure on said at least one second pressure control device (22) from a vacuum source or from atmospheric pressure.
Claim 3
Dependent Claim
23 words
The apparatus according to claim 1, in which the vacuum source is embodied by means of the intake tube (10) of the engine.
Claim 4
Dependent Claim
91 words
The apparatus according to claim 1, in which the at least first and second pressure control devices include an element (24), which is switched out of an initial position by means of the vacuum of the vacuum source (10) in opposition to a restoring tension, which element (24), when the vacuum is interrupted, is returned toward its initial position by means of the restoring tension to produce an overpressure in the fuel tank (36) when the regenerating valve (32) and the shutoff valve (42) connected to the absorption filter are closed.
Claim 5
Dependent Claim
90 words
The apparatus according to claim 2, in which the at least first and second pressure control devices include an element (24), which is switched out of an initial position by means of the vacuum of the vacuum source (10) in opposition to a restoring tension, which element (24), when the vacuum is interrupted, is returned toward its initial position by mean of the restoring tension to produce an overpressure in the fuel tank (36) when the regenerating valve and the shutoff valve (42) connected to the absorption filter are closed.
Claim 6
Dependent Claim
48 words
The apparatus according to claim 3, in which the switchable element is embodied as a diaphragm (24), which is mounted in a pressure tight housing as a dividing element between a chamber which communicates with the fuel tank and a chamber which communicates with the vacuum source (10).
Claim 7
Dependent Claim
48 words
The apparatus according to claim 4, in which the switchable element is embodied as a diaphragm (24), which is mounted in a pressure tight housing as a dividing element between a chamber which communicates with the fuel tank and a chamber which communicates with the vacuum source (10).
Claim 8
Dependent Claim
18 words
The apparatus according to claim 5, in which the diaphragm (24) is associated with a restoring spring (26).
Claim 9
Dependent Claim
18 words
The apparatus according to claim 6, in which the diaphragm (24) is associated with a restoring spring (26).
Claim 10
Dependent Claim
41 words
The apparatus according to claim 5, in which a reversing valve (18) is provided by means of which the chamber, which communicates with the vacuum source, selectively communicates with the vacuum source (10) and with ambient air via a connection 44.
Claim 11
Dependent Claim
41 words
The apparatus according to claim 6, in which a reversing valve (18) is provided by means of which the chamber, which communicates with the vacuum source, selectively communicates with the vacuum source (10) and with ambient air via a connection 44.
Claim 12
Dependent Claim
41 words
The apparatus according to claim 7, in which a reversing valve (18) is provided by means of which the chamber, which communicates with the vacuum source, selectively communicates with the vacuum source (10) and with ambient air via a connection 44.
Claim 13
Dependent Claim
41 words
The apparatus according to claim 8, in which a reversing valve (18) is provided by means of which the chamber, which communicates with the vacuum source, selectively communicates with the vacuum source (10) and with ambient air via a connection 44.
Claim 14
Dependent Claim
28 words
The apparatus according to claim 1, in which a restriction nozzle (16) is provided between the at least first pressure control device (18), and the vacuum source (10).
Claim 15
Dependent Claim
28 words
The apparatus according to claim 2, in which a restriction nozzle (16) is provided between the at least first pressure control device (18), and the vacuum source (10).
Claim 16
Dependent Claim
28 words
The apparatus according to claim 3, in which a restriction nozzle (16) is provided between the at least first pressure control device (18), and the vacuum source (10).
Claim 17
Dependent Claim
28 words
The apparatus according to claim 5, in which a restriction nozzle (16) is provided between the at least first pressure control device (18), and the vacuum source (10).
Claim 18
Dependent Claim
28 words
The apparatus according to claim 7, in which a restriction nozzle (16) is provided between the at least first pressure control device (18), and the vacuum source (10).
Claim 19
Dependent Claim
28 words
The apparatus according to claim 9, in which a restriction nozzle (16) is provided between the at least first pressure control device (18), and the vacuum source (10).
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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) | 1999-09-10 | 2000-03-11 | 2000-09-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-09-10 | 2004-03-11 | 2004-09-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-09-10 | 2008-03-11 | 2008-09-10 | $7700.00 | Window Closed / Lapsed |