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(12) Patent: | (11) CA 2144246 |
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(54) English Title: | BRAKE VALVE WITH PREFILL CHAMBER UNLOADING |
(54) French Title: | DISTRIBUTEUR DE FREINAGE AVEC DELESTAGE DE LA PRECHAMBRE |
Status: | Expired and beyond the Period of Reversal |
(51) International Patent Classification (IPC): |
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(72) Inventors : |
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(73) Owners : |
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(71) Applicants : |
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(74) Agent: | BORDEN LADNER GERVAIS LLP |
(74) Associate agent: | |
(45) Issued: | 1999-05-04 |
(22) Filed Date: | 1995-03-09 |
(41) Open to Public Inspection: | 1996-09-10 |
Examination requested: | 1995-03-09 |
Availability of licence: | N/A |
Dedicated to the Public: | N/A |
(25) Language of filing: | English |
Patent Cooperation Treaty (PCT): | No |
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(30) Application Priority Data: | None |
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Left and right two stage brake valves communicate fluid
pressure to left and right brake mechanism. Each brake valve
has an inlet for receiving pressurized brake fluid from a
pump, a reservoir port, a stepped bore and a stepped piston
member comprising a larger diameter prefill piston and a
smaller diameter high pressure piston. The stepped piston is
movable away from a rest position to transfer fluid to the
brake mechanism. The stepped bore and the stepped piston form
a high volume prefill chamber and a high pressure chamber.
The high pressure piston has a groove communicated with the
brake mechanism, and the groove communicates with the inlet
when the high pressure piston has moved a certain distance to
transfer fluid from the high pressure chamber to the brake
mechanism. The prefill piston has a sealing land and a second
land on either side of a sealing ring which is slidable in the
stepped bore. The sealing land sealingly engages the sealing
ring when the prefill piston moves to transfer fluid from the
prefill chamber to the brake mechanism. The sealing land is
spaced apart from the sealing ring by a distance which is
greater than the distance between the groove and the inlet
when the stepped piston is in its rest position.
Cette invention concerne des robinets de freinage bi-étagés, un gauche et un droit, qui alimentent en liquide sous pression les mécanismes de freinage correspondants. Chaque robinet comporte une admission de liquide de frein sous pression provenant d'une pompe, un orifice de retour vers un réservoir, un alésage à gradin et un piston à gradin dont la partie à grand diamètre a une fonction de préremplissage et la partie à petit diamètre une fonction d'alimentation sous haute pression. Ce piston est mobile entre une position de repos et une position de refoulement de liquide vers le mécanisme de freinage. L'alésage à gradin et ce piston définissent ensemble une chambre de préremplissage à grand volume et une chambre haute pression. La partie du piston assurant l'alimentation sous haute pression comporte une gorge mettant en communication le mécanisme de freinage et l'admission précitée lorsqu'elle s'est déplacée d'une certaine distance pour refouler le liquide de la chambre haute pression vers le mécanisme de freinage. La partie du piston assurant le préremplissage comporte, de part et d'autre d'une bague d'étanchéité glissée dans l'alésage à gradin, une portée d'étanchéité et une seconde portée. La première portée prend appui sur la bague d'étanchéité lorsque la partie du piston assurant le préremplissage se déplace pour refouler le liquide de la chambre de préremplissage vers le mécanisme de freinage. La portée d'étanchéité est espacée de la bague d'étanchéité d'une distance supérieure à la distance entre la gorge et l'admission précitées lorsque le piston à gradin est au repos.
Note: Claims are shown in the official language in which they were submitted.
Note: Descriptions are shown in the official language in which they were submitted.
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Please note that "Inactive:" events refers to events no longer in use in our new back-office solution.
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Description | Date |
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Inactive: Cover page published | 2008-07-25 |
Time Limit for Reversal Expired | 2006-03-09 |
Letter Sent | 2005-03-09 |
Grant by Issuance | 1999-05-04 |
Inactive: Final fee received | 1998-11-26 |
Pre-grant | 1998-11-26 |
Notice of Allowance is Issued | 1998-06-04 |
Notice of Allowance is Issued | 1998-06-04 |
Letter Sent | 1998-06-04 |
Inactive: Status info is complete as of Log entry date | 1998-06-02 |
Inactive: Application prosecuted on TS as of Log entry date | 1998-06-02 |
Inactive: Approved for allowance (AFA) | 1998-04-30 |
Application Published (Open to Public Inspection) | 1996-09-10 |
All Requirements for Examination Determined Compliant | 1995-03-09 |
Request for Examination Requirements Determined Compliant | 1995-03-09 |
There is no abandonment history.
The last payment was received on 1999-03-08
Note : If the full payment has not been received on or before the date indicated, a further fee may be required which may be one of the following
Please refer to the CIPO Patent Fees web page to see all current fee amounts.
Fee Type | Anniversary Year | Due Date | Paid Date |
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MF (application, 3rd anniv.) - standard | 03 | 1998-03-09 | 1998-03-06 |
Final fee - standard | 1998-11-26 | ||
MF (application, 4th anniv.) - standard | 04 | 1999-03-09 | 1999-03-08 |
MF (patent, 5th anniv.) - standard | 2000-03-09 | 2000-03-08 | |
MF (patent, 6th anniv.) - standard | 2001-03-09 | 2001-03-08 | |
MF (patent, 7th anniv.) - standard | 2002-03-11 | 2002-03-08 | |
MF (patent, 8th anniv.) - standard | 2003-03-10 | 2003-03-07 | |
MF (patent, 9th anniv.) - standard | 2004-03-09 | 2004-02-20 |
Note: Records showing the ownership history in alphabetical order.
Current Owners on Record |
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DEERE & COMPANY |
Past Owners on Record |
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DOUGLAS M. DURANT |