Fluid handling – Line condition change responsive valves – With separate connected fluid reactor surface
Patent
1994-09-30
1997-01-28
Hepperle, Stephen M.
Fluid handling
Line condition change responsive valves
With separate connected fluid reactor surface
13750515, 13750542, 137508, B60T 830
Patent
active
055970125
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to a valve with a fluid pressure threshold, capable of producing an outlet pressure which is shifted with respect to an inlet pressure of this fluid, this valve comprising: a body in which is pierced at least one cylindrical bore; a piston defining, in this bore, a first chamber into which there emerges a pressure inlet, and a second chamber into which there emerges a pressure outlet, this piston being capable of sliding in sealed fashion in the bore, from a rest position as far as a limiting position, under the effect of the inlet pressure and counter to a first force which is exerted by first elastic means; a valve element carried by the piston and capable of causing the two chambers to communicate with one another when it is open; and a push rod located in the second chamber facing the valve element and capable of causing the latter to open when this push rod and the valve element are urged towards one another with a force greater than a predetermined opening threshold.
A valve of this type is described, for example, in document FR-A1-2,679,856 and can be used in a braking system, particularly for an electric vehicle.
Despite their certain benefit, this type of valve a prior exhibits the defect, in their initial design, of allowing a residual pressure to remain in the outlet chamber, which residual pressure can be eliminated only by using separately controlled additional means, for example an electromagnet.
The present invention lies within this context and aims to propose simple, inexpensive means capable of eliminating the residual pressure automatically.
To this end, the valve of the invention, made up in accordance to the preamble hereinabove, is essentially characterized in that the push rod closes the second chamber in sealed fashion downstream of the pressure outlet, in that this push rod slides in this second chamber under the effect of the outlet pressure, over a stroke of determined length, and counter to a second force exerted by a second elastic means, which second force is greater than the opening threshold, and in the same direction as the first force, in that the stroke of the push rod is defined between a rest position which this push rod adopts when the piston is in its rest position, and a limiting position of this push rod, in which the latter encounters a stop piece secured to the body, in that this push rod opens the valve element when it is in its rest position, the length of the stroke of the push rod being greater than a relative displacement which the push rod and the piston have to undergo from their rest position in order to close the valve element, and in that the rest position and the limiting position of the piston are separated by a distance at least equal to that which separates the position of the push rod for which the valve element closes from the limiting position of this push rod in which the latter encounters the stop piece.
Moreover, the production of this valve is greatly simplified by making provision for the piston and the push rod to be subjected, by the outlet pressure, to respective forces which are exerted on different pressure cross-sections respectively, the pressure cross-section of the piston being greater than the pressure cross-section of the push rod.
Other characteristics and advantages of the invention will emerge clearly from the description thereof which is given hereafter, by way of non-limiting example, with reference to the appended drawings in which:
FIG. 1 is a sectional view of a valve in accordance with the invention, represented in rest position;
FIG. 2 is a reduced view similar to FIG. 1;
FIG. 3 is a reduced view similar to FIG. 1, in which the valve is represented during operation;
FIG. 4 is a reduced view similar to FIG. 1, in which the valve is represented at the end of operation; and
FIG. 5 is a pressure diagram, representing the operation of the valve.
As shown in FIG. 1, the valve of the invention essentially comprises a body 1; in which is pierced at least one cylindrical bore 1a, 1b, a piston 2, a val
REFERENCES:
patent: 3405978 (1968-10-01), Lepelletier
patent: 3488095 (1970-01-01), Rath
patent: 4838305 (1989-06-01), Reinartz et al.
AlliedSignal Europe Services Techniques
Hepperle Stephen M.
McCormick Jr. Leo H.
LandOfFree
Valve with a threshold with retractable push rod 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 with a threshold with retractable push rod, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Valve with a threshold with retractable push rod will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-936688