Fluid-pressure and analogous brake systems – Automatic – Application valve
Reexamination Certificate
2000-05-25
2004-08-03
Lavinder, Jack (Department: 3683)
Fluid-pressure and analogous brake systems
Automatic
Application valve
C303S063000, C137S102000
Reexamination Certificate
active
06769744
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This application relates to a combined or integrated spring brake modulating valve and relay valve that are contained in a single housing for an air brake system.
2. Discussion of the Art
It is common in presently available brake circuits to employ a separate modulation valve with a relay valve or with a separate quick-release valve. For example,
FIG. 1
illustrates a six-by-four straight truck, i.e., a non-towing vehicle, that employs spring brakes for parking the vehicle and in which pressurized air is delivered to the spring brakes to release them during normal operation. As shown in
FIG. 1
, each wheel includes a brake chamber connected with a relay valve to provide air pressure to the drive axle and selectively control service application of the brakes. In addition, each wheel includes a spring brake chamber selectively supplied with air to release a large mechanical spring typically used for the park function. Air pressure to these spring brake chambers releases the mechanical spring and allows the vehicle to roll.
As is generally known in the art, if a primary circuit fails, it is desirable to take advantage of the spring brakes, yet modulate the operation of the spring brakes through a foot control valve. This is provided by the spring brake modulation valve so that the spring brakes are selectively applied through operation of the foot control valve. The secondary circuit controls the steer axle (not shown). This arrangement provides a desired braking action and modulation of the spring brakes when required.
FIG. 2
illustrates a four-by-two or six-by-two straight truck configuration. Again, a spring brake modulation valve is used in conjunction with a separate spring brake quick release valve. It is evident from a comparison of
FIGS. 1 and 2
that different system configurations and plumbing arrangements are thus encountered by truck manufacturers even though the brake needs are not entirely dissimilar. Thus a need exists for simplified plumbing for the truck manufacturers that provides standardized installation across all of its vehicles. In addition, enhanced performance characteristics are always desirable.
SUMMARY OF THE INVENTION
The present invention provides an integrated spring brake modulating relay valve that simplifies known, multi-component systems.
More particularly, the valve includes a housing having a control port, supply port, delivery port, exhaust port, and primary and secondary circuit brake ports that communicate with a chamber in the housing. A first piston received in the housing moves in response to pressure from the control port. A second piston monitors the primary and secondary circuits and modulates spring brake pressure if the primary circuit fails. An exhaust valve is interposed between the supply and delivery ports and controls communication with the exhaust port to selectively supply and release the spring brakes.
The first or relay piston is connected to the second or modulating piston through a biasing spring. Thus, the pistons can operate in unison but are also adapted to move relative to one another for their particular functions.
A primary benefit of the invention is the ability to integrate separate components into a multi-component arrangement in a single housing.
Another benefit of the invention resides in the improved response time, while maintaining all of the features and benefits of known systems.
Yet another benefit results from the simplified plumbing and standardized installation for truck manufacturers.
Still other features and benefits of the invention will become apparent to those skilled in the art upon reading and understanding the following detailed description.
REFERENCES:
patent: 3836209 (1974-09-01), Neisch
patent: 3861754 (1975-01-01), Kruke et al.
patent: 3902764 (1975-09-01), Sebo
patent: 3937975 (1976-02-01), Yanagawa et al.
patent: 3944294 (1976-03-01), Masuda et al.
patent: 4003605 (1977-01-01), Fannin
patent: 4145091 (1979-03-01), Bueler et al.
patent: 4696521 (1987-09-01), McCann et al.
patent: 4926907 (1990-05-01), Fauck et al.
patent: 5553928 (1996-09-01), Hart et al.
patent: 5927072 (1999-07-01), Vannette
patent: 6116280 (2000-09-01), Goodell
patent: 6179391 (2001-01-01), Eberling et al.
patent: 3515386 (1986-11-01), None
patent: 3722306 (1989-01-01), None
patent: 0 407 751 (1990-06-01), None
patent: GB-2097878 (1982-11-01), None
patent: 0223935 (1987-06-01), None
patent: 0277465 (1988-08-01), None
patent: 0308375 (1989-03-01), None
patent: 0314932 (1989-05-01), None
patent: 0411355 (1991-02-01), None
patent: 0478515 (1992-04-01), None
patent: 2598372 (1987-11-01), None
patent: 1252 169 (1969-09-01), None
patent: 61222855 (1986-10-01), None
Eberling Charles
Kemer John
Knight Dave
Marsh Andrew
Ross Richard T.
Bendix Commercial Vehicle Systems LLC
Burch Melody M.
Calfee Halter & Griswold LLP
Lavinder Jack
LandOfFree
Spring brake modulating relay valve does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Spring brake modulating relay valve, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Spring brake modulating relay valve will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3300738