Fluid handling – Removable valve head and seat unit – Threaded into valve casing
Reexamination Certificate
1999-03-24
2001-02-27
Hepperle, Stephen M. (Department: 3753)
Fluid handling
Removable valve head and seat unit
Threaded into valve casing
Reexamination Certificate
active
06192921
ABSTRACT:
The invention relates to a screw-in cartridge valve and a screw-in cartridge valve assembly.
Screw-in cartridge valves or screw-in cartridge valve assemblies are of advantage in the high pressure—hydraulic field in order to realise different valve function variants in a space-saving manner, e.g. in block-structures. Typical cases of application from the practice, e.g. are described in product information P 7710-1 “screw-in cartridge valves type C”, of the company Heilmeier & Weinlein, Fabrik für Oel-Hydraulik GmbH & Co. KG, edition 03/95 or the technical print D 7470-1 “2/2-ports-screw-in cartridge valves EM” of the company Heilmeier & Weinlein, Fabrik für Oel-Hydraulik GmbH & Co. KG, March 1996. The threaded bore into which the screw-in cartridge valve is to be screwed is communicating with pressure media passages at which the respective needed valve function is required. The threaded bore can be provided in a block as well as directly in a hydraulic component like a hydraulic cylinder or a hydraulic motor and normally is open towards an exterior side where ambient pressure is present. Sealing against said exterior side either is carried out by means of a sealing ring pressed against said exterior side or a sealing ring provided in said threaded bore close to its exterior mouth. In any case the provided sealing ring is activated by means of the thread tightening tension of the screwed-in valve housing of said screw-in cartridge valve.
Since in operation normally high pressure is biasing said valve housing counter to the screw-in-direction and since pressure impacts are occurring during operation a loosening torque is generated in the threaded connection (due to the pitch angle) which torque, e.g. after 50,000 load switches, may loosen the valve housing in said threaded bore which may disturb the valve the functions or may even eliminate it. Since not in all cases of applications a torque metering wrench is used for mounting said screw-in cartridge and since, furthermore, only with relatively small bore diameters, e.g. less than 16 mm, a sufficiently strong tightening torque is possible, inter alia depending on the material matching between the valve housing and the basic body (steel, cast iron, aluminium, etc.) this leads to a significant disadvantage of screw-in cartridge valves or screw-in cartridge valve-assemblies.
REFERENCES:
patent: 4611629 (1986-09-01), Seiffert
patent: 4823832 (1989-04-01), Rodstein
patent: 5050633 (1991-09-01), Tarnay et al.
patent: 5217260 (1993-06-01), Boticki
patent: 5584323 (1996-12-01), Yamamuro
patent: 5590683 (1997-01-01), Bennett
patent: 5617890 (1997-04-01), Brehm et al.
patent: 5718264 (1998-02-01), Sturman
patent: 19625349 A1 (1998-02-01), None
patent: 0 676 548 A1 (1995-11-01), None
Cook Alex McFarron Manzo Cummings & Mehler, Ltd.
Heilmeier & Weinlein Fabrik fur Oel-Hydraulik GmbH & Co.
Hepperle Stephen M.
LandOfFree
Screw-in cartridge valve and screw-in cartridge valve assembly does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Screw-in cartridge valve and screw-in cartridge valve assembly, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Screw-in cartridge valve and screw-in cartridge valve assembly will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2608413