Brakes – Internal-resistance motion retarder – Controlled by an operator remote from retarder
Reexamination Certificate
2000-07-27
2001-10-23
Schwartz, Christopher P. (Department: 3613)
Brakes
Internal-resistance motion retarder
Controlled by an operator remote from retarder
C188S266600
Reexamination Certificate
active
06305512
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a valve having a pressure dependent reaction.
2. Description of the Related Art
A valve that reacts as a function of pressure for an adjustable vibration damper is disclosed in DE 44 01 393 C1 and comprises a piston rod axially movably arranged in a cylindrical tube filled with damping liquid. The cylindrical tube has a connection to the pressure-dependent valve, which is driven by an adjusting device to which pressure is applied, the adjusting device having a valve body which is axially movable and is driven by a pressure intensifier mounted so as to float in a pressure chamber. The pressure intensifier is supported by at least one spring which prestresses the pressure intensifier and determines the steepness of an opening characteristic of said valve at given valve cross sections. One problem is that it is necessary to effectively prevent any leak at the pressure intensifier, originating from the pressure connection, that can cause maladjustment of the valve.
In addition, this known valve has a relatively high thermal load. Therefore, the compressed-air feed to the valve may be achieved only with a relatively high constructional outlay, since commercially available plastic hoses would scorch under the high thermal load. Metal tubes cannot be used, or can be used only under certain conditions, in the application of the valve to a vibration damper, since the vibration damper executes relatively large springing movements, which load the metal tube.
SUMMARY OF THE INVENTION
The object of the present invention is to develop a pressure dependent valve so that the aforementioned leaks do not have any adverse effect on the action of the valve, while reducing thermal loading of the components of the valve.
Briefly stated, the present invention comprises a pressure operated valve including an adjusting device, a spring and a vent connection. The adjusting device is axially movably arranged in a pressure chamber defined in the valve and comprises a valve body and a pressure intensifier. A space between the valve body and valve face defines a valve passage cross section. The spring is operatively arranged for holding the pressure intensifier in a floating arrangement in the pressure chamber. The pressure intensifier has a first side exposed to a pressure in the pressure connection opening and a second side facing away from the pressure connection opening. The second side of the pressure intensifier adjoins a low pressure chamber within the pressure chamber. The vent connection is an inflow restrictor arranged between the lower pressure chamber and a space having a lower pressure than the low pressure chamber.
According to the invention, the object related to leaks is achieved by the pressure intensifier. On the side of the pressure intensifier facing away from the pressure connection opening, adjoining a low-pressure chamber, is a vent connection to a still lower pressure level, the vent connection being at least partly covered by an inflow restrictor.
Although the inflow restrictor permits compressed air which flows into the low-pressure chamber as leakage air to escape from the latter and ensures that no compressive force builds up on the intensifier in the low-pressure chamber, it is nevertheless impossible for spray water or dust to penetrate unimpeded into the valve.
Provision is therefore made for the inflow restrictor to be formed by a cap. The cap forms a shield which, for example, leaves only a radial outflow direction free for the escaping leakage air.
According to an advantageous embodiment, the low-pressure chamber is defined by an insert, in which the pressure intensifier is guided so as to move axially, the insert being arranged in a tubular connecting piece that accommodates the entire valve, and the vent connection extending in sections from the low-pressure chamber through the walls of the insert and of the tubular connecting piece.
With regard to the required functional reliability, the insert has an installation orientation marking, for sections of the vent connection in the tubular connecting piece and in the insert form to overlap.
For this purpose, the tubular connecting piece has an anti-rotation device which is aligned radially inward toward the insert and engages in the installation orientation marking.
To maintain reasonable production costs of the installation orientation mark, the anti-rotation device is formed by a pin that passes through the tubular connecting piece. In a second function, the pin is used to fix the inflow restrictor designed as a cap.
In a further embodiment, the installation orientation marking is formed by an axial groove. This provides the advantage that the pin with the cap can already be fixed to the tubular connecting piece, and the insert in the tubular connecting piece comes to rest on the inner end of the pin until, as a result of rotation of the insert, the pin can engage in the axial groove in the insert and hence fix the insert in the circumferential direction. A pin can be formed by a screw, a rivet or else a notched nail or any other desired element that passes through the wall of the tubular connecting piece.
In order for condensed moisture or moisture which has penetrated in spite of the inflow restrictor to flow out of the valve, the vent connection for the compressed air, with respect to the installation position of the tubular connecting piece, is arranged at least in the vicinity of the lowest point. In addition, the insert has a base with a wall that widens like a funnel, so that no residual moisture can remain in the valve.
The object with respect to the heat problem is achieved by the pressure connection having a thermal insulator with respect to the further valve components.
This makes it possible for a simple plastic hose and also a plastic connecting element to be used for the pressure supply, which has only a low thermal resistance but is permanently elastic.
In a further advantageous embodiment, the insulator is formed by a cover that closes the valve. It has been shown to be particularly advantageous for the cover to consist of a polymer.
In order that the cover also withstands relatively high control pressures, the cover is fixed by a cover securing ring. The cover securing ring covers the cover over a large area and therefore supports it reliably.
As an alternative to a polymer cover, the insulator can comprise a sleeve within the cover. Suggested insulators are a polymer or else a metal with a low thermal conductivity, for example V
2
A.
For this purpose, the sleeve can border the cover at the edge, similarly to a shrunk-on ring. Alternatively, the sleeve encloses only the pressure connection opening.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of the disclosure. For a better understanding of the invention, its operating advantages, and specific objects attained by its use, reference should be had to the drawing and descriptive matter in which there are illustrated and described preferred embodiments of the invention.
REFERENCES:
patent: 4650042 (1987-03-01), Knecht et al.
patent: 4880086 (1989-11-01), Knecht et al.
patent: 5335757 (1994-08-01), Knecht et al.
patent: 5392885 (1995-02-01), Patzenhauer et al.
patent: 5431259 (1995-07-01), Mizutani et al.
patent: 5472072 (1995-12-01), Bumgarner
patent: 5960915 (1999-10-01), Nezu et al.
patent: 6079526 (2000-06-01), Nezu et al.
patent: 6182687 (2001-02-01), Forster et al.
patent: 6182805 (2001-02-01), Kashiwagi et al.
patent: 1 041 742 (1959-04-01), None
patent: 70 47 641 (1970-12-01), None
patent: 34 34 877 (1988-04-01), None
patent: 41 05 771 (1992-08-01), None
patent: 42 33 319 (1994-04-01), None
patent: 44 01 393 (1995-04-01), None
patent: 44 27 559 (1995-08-01), None
patent: 691 20 008 (1996-12-01), None
Assiioff Thorsten
Heinz Norbert
Heyn Steffen
Kuhnel Joachim
Kutsche Thomas
Cohen & Pontani, Lieberman & Pavane
Mannesmann Sachs AG
Schwartz Christopher P.
LandOfFree
Valve which reacts as a function of pressure, especially for... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Valve which reacts as a function of pressure, especially for..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Valve which reacts as a function of pressure, especially for... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2585357