FR2535798A1 - Charge-loss delay valve - Google Patents

Abstract

The valve 7 located inside the hollow valve body 1 comprises a seal 8 which is applied against a seat 3c of the shell 3 of the body 1 by the intermediary of a spring 5. The face 7b of the valve 7 which is associated with the ring seal 8 is indented with a spiral 7c whose origin 7d is located on the periphery of the said valve while its end 7e is located in a central zone of the considered face located inside the ring seal 8. Pneumatic installation.

Description

 The present invention relates to a delay valve whose operation is generated by pressure drops to which the flow is subjected.

The delay valve according to the invention comprises a hollow body and a valve disposed in this body, said valve comprising a face in which a spiral is hollowed out, the groove of which is open on the face considered, said groove being closed by the seal, exception made of its origin which opens onto the periphery of the valve and of its outlet which is located in a central zone of the valve, that is to say inside the annular seal. Thus, when a flow of fluid causes by pressure or by one of pressure enters the valve through one of its outputs, it takes a determined time for the pressure to apply to the other outlet
The appended drawing, given by way of example, will allow a better understanding of the invention, the characteristics which it presents and the advantages which it is capable of providing:
A single figure in the drawing is a cross section of a delay valve established in accordance with the invention.

 The valve according to the invention comprises a hollow body 1 produced by means of two shells 2 and 3 assembled together in a sealed manner, for example by welding. The shells are advantageously made of plastic, their welding being carried out for example by ultrasound.

Each shell comprises an external central boss 2a, respectively 3a suitably drilled in order to make the interior of the body 1 communicate with the exterior, each hole entering reference 2b, 3bo For the convenience of the vocabulary we will call the sets 2a-2b, 3a -3b the two outputs of the delay valve
The shell 2 comprises an internal central cavity 2c retaining a filter 4, which cavity is surrounded by a stepped chimney 2d constituting on its smallest diameter a centering for a spring 5 whose role will be better explained below.

 The shell 3 has a ring seat 3c, the diameter of which is preferably greater than that of the path 2d. Inside the shell 3, a 3d depression has been provided in which a filter 6 is housed. Thus the outlet towards the inside of each of the holes 2b, 3b of the two valve outlets is provided with a filter intended for retain all impurities from the fluid flow passing through the valve.

 A valve 7 is placed inside the shell 3. It includes a central projection 7a around which the spring 5 is placed.

The valve considered also has a face 7b against which is pressed an annular seal 8 which is applied against the seat 3c by the spring 5.

 In accordance with the invention, the face 7b of the valve 7 which receives the seal 8 is hollowed out with a spiral 7c, the groove of which leaves from the periphery of said valve to end up in an area of the face in question located inside the seal. annular 8. In other words the groove of the spiral 7e is closed by the corresponding face of the seal 8, except for its origin 7d and its termination 7e, so that it forms a channel ausert at its two ends.

The operation follows from the explanations which proceed
When a vacuum is applied in the hole 3b it communicates inside the hollow body 1 so that the fluid therein as well as that located upstream of the opposite outlet (2a-2b) is sucked into said hole 3b. However, the fluid must necessarily enter the spiral 7e by its origin 7d and then travel the entire length of its groove to emerge by its termination 7e located inside the seal 8. Thus the flow of fluid is subjected to pressure drops important so that it can arrive in the hole 3b under significant pressure only after a time which is a function of the length and the section of the groove of the spiral.

 If the vacuum is applied in 2b it causes the valve to be raised and no delay is applied to the transmission of the vacuum in the hole 3b.

 Finally we can assume that a pressurized fluid is sent into the valve through the hole 2b to come out through that 3b. It is only after a time of completion that the pressure prevailing in the hole 2b will be transmitted in that 3b since the flow will still have to cross the spiral 7e.

 It is obvious that the length and the section of the spiral 7e are determined according to the pressure which it is desired to obtain after a fixed time, this pressure being able to be equal or lower than that initially applied to the valve.

 It should moreover be understood that the foregoing description has been given only by way of example and which in no way limits the field of the invention from which one would not depart by replacing the execution details described by all other equivalents.

Claims (2)

R E-V E N D I C A T I 0 N S  1. Delay valve, characterized in that it comprises a hollow body (1) with two opposite outlets (2a-2b, 3a-3b), one of which (3a-3b) is surrounded by an annular seat (3c) while a valve (7) disposed in the hollow body (1) is applied elastically against said seat (3c) by means of an annular seal (8-, the face (7b) of said valve which carries the seal ( 8) being hollowed out by a groove (7c) starting from the inside of it to end up inside said seal, so that when a vacuum or a pressure is applied respectively downstream or upstream of the valve ( 7), it is transmitted with delay to the opposite exit from the body (1) due to the pressure losses that the flow undergoes when traversing the groove (7c).  2. Delay valve according to claim 1, characterized in that the groove (7c) is produced in the form of a spiral whose origin (7d) opens onto the periphery of the valve (7) while. that its outlet (7th) takes place in an area of the latter located inside the seal (8).