FR2792388A1 - Pressure reduction float valve has elongated rod with headspring biased against outlet nozzle - Google Patents

Abstract

The pressure reduction float valve has an elongated rod (20) and an enlarged head (21) formed as a disc attached to or formed integrally with the rod. The valve is spring (1) biassed against an outlet nozzle (3). The spring engages the rod of the valve. The valve can have an axial cross passage.

Description

The present invention relates to a floating valve for

  balanced pressure, especially for high pressures, and a balanced pressure reducer

comprising such a valve.

  Balanced pressure reducers with floating valves are well known in the art. Examples of this type of device are in particular disclosed in documents FR-2,668,808, US-5,413,096 and US-5,810,041 which are

  incorporated into this application for reference.

  These documents disclose balanced pressure reducers comprising a floating valve adapted to seal an outlet nozzle, said valve having an elongated rod ending at one end by an enlarged head of larger diameter in the form of a disc. This floating valve is biased by a spring towards its closed position in which it closes the outlet nozzle, said spring cooperating with said valve head. Consequently, the dimension of said head must be large enough to be able to form a support for said spring. This involves a number of drawbacks. Thus, due to the high pressures which apply to said valve, it is generally necessary to provide a non-cylindrical stabilizing collar arranged around the head and which cooperates at least partially with the walls of the chamber in

  which the valve slides, in order to avoid lateral displacement of said floating valve.

  The presence of this collar, more precisely described in the documents of the prior art FR-2,668,808 and US-5,413,096 cited above, implies an air passage around the head of the

  relatively limited valve, which has a negative influence on the performance of the regulator.

  On the other hand, the fact that the spring acts on the radial end of the valve head can create difficulties for correct positioning of the valve against the outlet nozzle, and can create friction between the elongated piston rod and the guide bore in which the latter slides, which may in the long run lead to risks of leakage through the

  O-ring provided in said bore.

  The object of the present invention is to provide a floating valve for a balanced pressure reducer, particularly for high pressures, which does not have the

disadvantages mentioned above.

  The present invention therefore aims to provide such a floating valve which is simple,

  and inexpensive to manufacture, and reliable in use.

  The present invention also aims to provide such a floating valve which ensures correct positioning of the valve head against the outlet nozzle in the closed position.

  and which minimizes the risk of wear, in particular by friction, and therefore of leaks.

  The present invention also aims to provide such a floating valve which makes it possible to improve the regulation performance, in particular in terms of constancy of the

  reduced pressure and increased air flow.

  The present invention therefore relates to a floating valve for balanced pressure reducer, particularly for high pressures, said valve having an elongated rod and an enlarged disc-shaped head, fixed to, or formed in one piece with said rod, said floating valve being biased by a spring against an outlet nozzle, said spring acting on

  said elongated rod of the floating valve.

  Advantageously, said valve has an axial through passage.

  The present invention also relates to a balanced pressure reducer,

  especially for high pressures, comprising such a floating valve.

  Preferably, said floating valve is slidably mounted in a valve unit comprising a blind bore forming a balancing chamber, in which said elongated rod can slide in leaktight manner, said spring being disposed in the bottom of said

blind bore.

  Advantageously, said bore comprises, near its upper edge, a

  O-ring seal in which said valve stem slides.

  Other characteristics and advantages of the present invention will appear more

  clearly during the following detailed description of a preferred embodiment of

  the present invention, given by way of nonlimiting example with reference to the attached single figure, in which is shown a schematic sectional view of a reduction gear

  pressure incorporating a floating valve according to the present invention.

  Referring to the single figure, there is shown an example of a pressure reducer comprising a floating valve according to the present invention, which corresponds substantially to the devices disclosed by the documents of the prior art FR-2,668,808 and US-5 413 096. The general structure and operation of the pressure reducer

  balanced according to the invention are substantially similar to those described in these documents.

  Therefore, the balanced pressure reducer of the present invention will not be described in detail below, but only the features forming part of the invention will be explained later. Document US Pat. No. 5,810,041 also discloses a balanced pressure reducer of the prior art to which the present invention can be applied. According to the invention, the floating valve comprises an elongated rod 20 provided at one end with an enlarged head 21 in disc shape which closes an outlet nozzle 3, in the valve closed position. The floating valve is biased towards this closed position by a spring 1, said valve being able to move axially towards an open position against the force of said spring 1 to regulate the pressure. In known manner, said elongated rod 20 of the valve slides in leaktight fashion in a bore 11 forming a balancing chamber produced in a valve unit 10, the sealing being preferably carried out using an O-ring 6 placed at the level of the upper edge 12 of said bore 11. Preferably, an axial through passage 30 is provided in the valve, crossing in their

  centers said head 21 and said rod 20.

  According to the present invention, the spring 1 acts directly on the elongated rod 20 of the floating valve. Preferably, this spring 1 is housed at the bottom of said bore 11, which is advantageously blind, and the spring bears on the one hand on the bottom of said bore and on the other hand on the lower end of the elongated rod 20. In this way, since the spring no longer has to cooperate with the valve head, the latter can have a

  reduced size, as visible in the single figure.

  The spring i disposed in the bottom of the bore 1 provides the following advantages: - the small spring 1 exerts its force on the elongated rod 20 of the valve practically on the longitudinal axis of symmetry of said valve. It follows that the position of the head 21 of the valve is much more precisely defined in the closed position against the outlet nozzle 3, so that the closing of the floating valve is faster and the pressure reduction is more constant. On the other hand, there is significantly less wear of the sealing part of the valve (generally formed by a coating or a plastic pad on or around said valve head). Indeed, the pressure exerted by the spring 1 of the invention is less than that exerted by the spring of the devices of the prior art, which cooperated with the head of the valve, so that the head 21 of the valve is not no longer pressed excessively against the outlet nozzle 3, which had the effect of damaging the tablet or the plastic coating provided at this location; - a more axial pressure of the spring 1 on the valve reduces the friction between the elongated rod 20 of the valve and the guide bore 11 in which said rod moves, which reduces wear and therefore the risk of leakage through the O-ring 6 provided in said bore; - The reduced size of the valve head 21 allows a passage of air around said head significantly greater compared to the valves of the prior art thus improving the control performance, especially in terms of air flow, made of a significant reduction in air vortices and a possibility of greater air passage; - The small spring of the present invention is simple and inexpensive to manufacture while being particularly reliable in ensuring perfect operation of the floating valve of the pressure reducer. The new floating valve of the present invention, and in particular the shape and position of the spring acting directly on it, is therefore particularly simple and therefore inexpensive to manufacture, but also very reliable in its operation and having a

  improved service life and performance compared to the prior art.

  This description has been made in relation more particularly to three documents

  of the prior art cited above, but it is understood that the present invention applies to all types of floating valve for balanced pressure reducer, and is not limited to the types or examples of embodiment disclosed in the prior documents

  as well as in the present description.

2792388

Claims (5)

Claims:   1.- Floating valve for balanced pressure reducer, particularly for high pressures, said valve having an elongated rod (20) and an enlarged disc-shaped head (21), fixed to, or formed in one piece with said rod ( 20), said floating valve being biased by a spring (1), against an outlet nozzle (3), characterized in that said spring (1) acts on said elongated rod (20) of the floating valve. 2.- floating valve according to claim 1, wherein said valve comprises a through axial passage.   3.- Balanced pressure reducer, especially for high pressures, characterized in   that it comprises a floating valve according to claim 1 or 2.   4.- balanced pressure reducer according to claim 3, wherein said floating valve is slidably mounted in a valve unit (10) having a blind bore (11) forming a balancing chamber, wherein said elongated rod (20) can slide from   sealingly, said spring (1) being disposed in the bottom of said blind bore (11).   5.- balanced pressure reducer according to claim 4, wherein said bore (11) comprises, near its upper edge (12), an O-ring seal (6)   in which said valve stem (20) slides.