helium escape valve

[JohnEaton]

The HRV is believed to have been co-developed by Doxa and Rolex, for which Rolex submitted patent number CH-A-492 246 on November 6, 1967. Although Rolex fitted Submariners (model 5513 - non date) with prototypes of this escape valve, which COMEX divers used successfully for years, they didn't actually begin to build the Helium Release Valve into their retail dive watches until 1971, this was when they produced the HRV equipped Sea-Dweller.

The HRV was developed to eliminate the need to unscrew the crown when saturation divers were decompressing in the decompression chamber. Under pressure, molecules of He2 helium gas [second smallest atom, hydrogen is smaller, however the He valence shell is filled and the H is not, think of a magnetic attraction with H2 and no magnetic attraction on He2 ] are able to infiltrate the tightest of seals and even the crystal on dive watches. [With respect to He2 the crystal acts as an osmotic membrane.]

If this gas is not released, manually or by valve, and pressure within the watch does not off gas at the rate of decompression allowing internal watch pressure to exceed ambient as the diver decompresses, the crystal of the watch can be blown off.

This unique problem was discovered by COMEX divers back in the 1960’s, and Rolex integrated the HRV into the Sea-dweller case to be automatically released when pressure within the Oyster case builds up to a critical level.

The HRV is made of Titanium and looks darker than the 904L stainless steel case.



CH-A-492 246 cross to United States Patent 5257247 [quote below, no drawing submitted]

Abstract:
This valve (1) for a watch case comprises a head (3) and a tube (4) onto which the head can be screwed. A stem (8) fixed to a core (5) borne by the head is surrounded by a return spring (7) bearing, on the one hand, under the head and, on the other hand, onto a bottom (3) exhibited by the tube through a ring (14) and a first packing (6). A second packing (18) is mounted under the head in line with the tube. When the head is screwed down the second packing (18) is compressed and the valve is inoperative and at the same time totally sealed. When the head is unscrewed the first packing (6) is able to rise up against the return force of spring (7) if the fluid pressure prevailing within the case is higher than that on the exterior thereof. An excessive interior pressure which can damage the case is thus avoided.
Inventors:
Miche, Marc-Andre (Bienne, CH)
Palix, Gerard (Bienne, CH)
Application Number:
008584
Filing Date:
01/25/1993
Publication Date:
10/26/1993

Assignee:
SMH Management Services AG (Biel, CH)
Primary Class:
368/290
Other Classes:
368/319
International Classes:
G04B 029/00, G04B 037/00
Field of Search:
368/287-291, 308, 319
US Patent References:
3453819 Jul, 1969 Simon 368/290.
3994125 Nov, 1976 Wenger 368/290.
4292682 Sep, 1981 Wenger 368/289.
4689158 May, 1978 Wenger 368/289.
Foreign References:
204911 Aug, 1937 CH.
337467 Mar, 1957 CH.
492246 Nov, 1967 CH.


Primary Examiner:
Miska, Vit W.
Attorney, Agent or Firm:
Griffin, Butler, Whisenhunt & Kurtossy
Claims:
What we claim is:

1. A safety valve comprising a hollowed-out head provided with a skirt and a central core extended by a stem, a tube onto which the head is mounted, such tube being intended to be secured onto a timepiece case and including a bottom traversed by the stem and a helical return spring surrounding the core and the stem, means being operable to enable the head to occupy an "out" position or an "in" position, a first end of the spring bearing under the head and a second end onto a ring which in turn compresses a first packing arranged on said bottom, a second packing being arranged under the head in line with the tube in a manner such when the head is in the "in" position said second packing is pressed against the tube, the valve then being inoperative and totally sealed, and when the head is in the "out" position said first packing is able to rise up against the return force of the spring if the fluid pressure prevailing within the case is higher than that prevailing on the exterior so as to avoid excessive pressure capable of damaging the case.

2. A valve as set forth in claim 1 wherein said means consist of threads formed on the outside of the tube, said threads cooperating with internal threading formed on the interior of the skirt in order to permit the head to take up an unscrewed "out" position or a screwed-down "in" position.

3. A valve as set forth in claim 1 wherein the first end of the spring bears on a ring surrounding the central core and resting under the head, such ring forming, together with the skirt and the underside of the head, a housing for the second packing.

4. A valve as set forth in claim 1 wherein the stem includes threads screwed into internal threading formed in the central core.
Description:
The present invention relates to a safety valve comprising a hollowed-out head provided with a skirt and a central core extended by a stem, a tube onto which the head is mounted, such tube being intended to be secured to a case of a timepiece and including a bottom traversed by the stem and a helical return spring surrounding the core and the stem.

BACKGROUND OF THE INVENTION

It is known to provide a watchcase with a valve.

Nevertheless, in existing designs, the purpose of the valve is to enable one either to inject a gas into the case in order to obtain therein a pressure greater than the ambient pressure, thus preventing penetration of water, vapour or dust to the interior of the case or, to the contrary, establish a vacuum within the case in order to protect the movement from the effects of air contained in the case at the time of its closure, or with the purpose of improving the tightness of the case by the ambient pressure contributing to force the different constitutive elements thereof against one another.

Nevertheless, such designs have never been employed in order to eliminate effects on the watchcase of a long immobilization of the latter in a gaseous medium under heavy pressure.

Effectively, it has been determined that whatever be the sealing qualities of watchcases provided up to the present, when they are subjected during relatively long periods on the order of several hundreds of hours to relatively heavy pressure on the order of several tens of atmospheres and especially when the surrounding atmosphere is formed of a gas having small dimension molecules as is the case with helium for instance which is frequently employed in diving bells, the pressure within the watchcase ends up by increasing considerably.

Such conditions of use are not hypothetical but exist in reality, in particular when the watch is employed at great depths underseas in the course of work taking place under a bell. The dive is said to be "in saturation" (reference to the standards annex of ISO standard 6425 for diver's watches).

During return of the watch into an atmosphere at normal pressure, and this in spite of the decompression stages which are necessary for the occupant of the bell, there arises an interior overpressure in the watchcase, which may bring about bursting of the latter, that is to say, ejection of the crystal in particular.

To overcome this difficulty, patent document CH-A-492 246 proposes a valve arranged in a manner to open automatically when the ambient pressure is lower than that prevailing within the case and to close in the inverse case in order to prevent that there occur within the case an interior over pressure susceptible to bring about deterioration of the case during intermittent employment of the watch in an over-pressurized gaseous medium and during passage of the watch from the over-pressurized medium to the medium at ordinary pressure.

Given that precautions are taken in order to avoid bursting of the watch during a return from great depths, but in a gaseous medium, the wearer of the watch may wish to employ the same watch for great depths, but in a liquid medium on such latter occasion. Now the design recommended by the cited document shows that the valve suffers from shortcomings if the high pressure is applied to the exterior of the watch. The 0 ring employed may roll out of its housing if a high pressure is applied onto the head of the valve. Otherwise, from the fact that the course of the valve is limited in the return direction, it is necessary to arrange the housing of the seal with great precision in order to assure good application of the latter onto the watchcase. Simply stated, it is not easy to design a valve opening easily when the interior pressure is greater than the ambient pressure and hermetically closing when the pressure is directed in the other sense. It may also be mentioned that the use of the timepiece in a liquid medium is much more frequent than utilization under a bell with a helium atmosphere. It is thus necessary that the valve guarantee a perfect sealing during submarine dives while assuring its role as safety valve if the timepiece is occasionally employed under a bell.

SUMMARY OF THE INVENTION

In order to guarantee such double function without fail, the valve of the present invention is characterized in that means are employed in order to permit the head to occupy an "out" position or an "in" position, that the first end of the spring bears under the head and the second end onto a ring compressing in turn a first packing arranged on said bottom and that a second packing is arranged under the head in line with the tube in a manner such that when the head is in the "in" position said second packing is pressed against the tube, the valve being then inoperative and totally sealed and when the head is in the "out" position said first packing is able to rise up against the return force of the spring if the pressure of the fluid prevailing within the case is higher than that prevailing at the exterior in order to avoid excessive pressure capable of damaging the case.

The invention will now be understood upon reading the description which follows and with the help of the drawing which illustrates it by way of example.

BRIEF DESCRIPTION OF THE DRAWING

The single figure is a cross-section taken in the valve of the invention, the right hand part showing the head in the "out" position and the left hand part the head in the "in" position.

DESCRIPTION OF THE PREFERRED EMBODIMENT

As is apparent on the figure, the safety valve 1 comprises a hollowed-out head 3 provided with a skirt 30 and a central core 5 extended by a stem 8. The head is mounted on a tube 4 secured to a caseband 2 forming a part of the case of a timepiece. The figure shows this fastening takes place by screwing of the tube into the caseband, the tube bearing threads 19 and the caseband an internal threading 20. Tube 4 includes a bottom 13 traversed by stem 8. Core 5 and stem 8 are surrounded by a helical return spring 7.

The valve is noteworthy in that it employs means to enable the head to occupy an "out" position (right hand side of the figure) or an "in" position (left hand side of the figure). As is seen on the figure, such means consist in threads 16 formed on the exterior of tube 4, such threads cooperating with internal threading 15 provided on the interior of skirt 30. The head may thus assume a screwed-down "in" position and an unscrewed "out" position. The invention is however not limited to the means shown here, such means may be different as for example the use of a bayonet-type closing.

The figure further shows that spring 7 bears under head 3 through its first end 31. The second end 32 of spring 7 bears against a ring 14 which compresses in turn a first packing 6 arranged on the bottom 13 exhibited by tube 4. It is also seen on the figure that a second packing 18 is arranged under head 3 in line with tube 4.

Thus, when head 3 is in the "in" position, the second packing 18 is pressed against tube 4. It follows that the valve is then inoperative and completely sealed. When the timepiece is employed in a liquid medium and at great depths the diver will screw down the head of the valve which renders the valve absolutely tight, not only through the effect of crushing the second packing 18, but further through the effect of additional compression of the first packing 6, the spring 7 developing an additional force on such first packing when head 3 is screwed down.

Inversely, when head 3 is in the "out" position, the return spring 7 is relaxed and the second packing 18 is no longer active. Thus, the first packing 6 is capable of rising up against the return force of spring 7 when the fluid pressure prevailing within the case is higher than that prevailing at the exterior. This is the case of the stay in the diving bell suggested hereinabove. Thus, in such case, the diver will unscrew the head of the valve to avoid an excessive pressure risking damage to the case, for example through ejection of the crystal.

In the embodiment illustrated on the figure, end 31 of the return spring 7 does not bear directly under head 3, but is supported under such head through a ring 10 surrounding the central core 5. The figure shows that ring 10 forms, together with skirt 30 and the underside of head 3, a housing 33 in which is placed the second packing 18. The figure also shows that stem 8 includes threads 22 which are screwed into internal threading 21 formed in the central core 5. Stem 8 is terminated by a head 23 enabling screwing the stem onto the core.

It will also be noted that skirt 30 comprises longitudinal knurling 28 permitting good gripping. Finally, tube 4 bears a collar 34 which on the one hand serves to limit the travel of the head and on the other hand enables sealing the tube relative to the caseband 2 through a packing 24.

[666 Bandit]

if you read that patent & understand the design it is pretty clear that it is not for an automatic HRV. It even explains how the valve is inoperable when it is screwed in. This is not the HRV used on the SD.

[gan1hck]

I can't seem to find the diagrams.

Anyway, the Omega and Rolex valves are essentially the same...the only difference is that the Omega one is covered with a crown and is not as water resistant when uncovered.

[atldavek]

It is apparent I am not smart enough to understand the patent, but it does say :
"This unique problem was discovered by COMEX divers back in the 1960’s, and Rolex integrated the HRV into the Sea-dweller case to be automatically released when pressure within the Oyster case builds up to a critical level."

So it is automatic and plus there isn't anywhere to screw in or unscrew the valve on the SD. Right? ( I don't own one.)

[gan1hck]

Originally Posted by simmonjam1

Thanks for the explanation.

Safe to say the average Joe diver wouldn't need the use of the HEV?

Interesting none the less!

you're welcome and correct.

[666 Bandit]

you are correct there is no way to unscrew it as described in this patent.

[JohnEaton]

Correct you do not unscrew the HRV in the sea dweller...

I'm at work and busy, perhaps I loaded the wrong patent, I'll check when I have time. But Bandit, I can tell you I have over 11,000 hours bottom time, have been in deco chambers and studied dive physics and chemical engineering...

So don't get an attitude with me unless you're Comex, DSI or Arthur Levy

[666 Bandit]

John, I am not trying to give you attitude, please don't take it that way. I am just trying to make sense of the information. I explained the way I beleived it was from what I know & what I have seen. The idea of a material that only lets helium pass is not impossible because it is a very small molecule, hence its ability to get inside the watch in the first place. I have seen several HEV valves that have a screw down crown which closely resemble the patent listed. Either way please accept my apology if you beleive I gave you an attitude, it really is not worth arguing over.

[jasonbellevue]

Originally Posted by gan1hck

I can't seem to find the diagrams.

Anyway, the Omega and Rolex valves are essentially the same...the only difference is that the Omega one is covered with a crown and is not as water resistant when uncovered.

It works the same. A picture is worth a thousand words, here you go.

[Jocke]

My one open at 0,5 psi.





Jocke

[jasonbellevue]

Originally Posted by Jocke

My one open at 0,5 psi.



Jocke

[steel4me]

jasonbellevue,

Aren't those pics identical? I mean two on the left look the same and 2 on the right look the same, yet the labels on each pair is "closed" and "open"???? am i missing any details?

[steel4me]

I think I got my ans ... I see the gaps now .... each pic is different...

[frostie]

Originally Posted by Jocke

My one open at 0,5 psi.





Jocke

you are crazy

Originally Posted by jasonbellevue

It works the same. A picture is worth a thousand words, here you go.

Nice post Jason

[TDH]

Jocke, Man you are hilarious

[gan1hck]

You know....now that I've thought about this topic for a little....

Why do we need the HEV at all?????

Why not just unscrew the crown when you're decompressing?

[JohnEaton]

Originally Posted by 666 Bandit

John, I am not trying to give you attitude, please don't take it that way. I am just trying to make sense of the information. I explained the way I beleived it was from what I know & what I have seen. The idea of a material that only lets helium pass is not impossible because it is a very small molecule, hence its ability to get inside the watch in the first place. I have seen several HEV valves that have a screw down crown which closely resemble the patent listed. Either way please accept my apology if you beleive I gave you an attitude, it really is not worth arguing over.

Sorry Bandit, I was juggling 4 or 5 things at once, I had a customer that didn't need anything unless he saw that I was busy at the computer in which case he had a dumb question, I just posted when I should not have, please accept my apology.

Here's a little info:





I'll post some more about this soon.

Originally Posted by gan1hck

You know....now that I've thought about this topic for a little....

Why do we need the HEV at all?????

Why not just unscrew the crown when you're decompressing?

That works too... It also works in reverse... Our Dive Doc (old navy guy) was a sadist... He would take newbies down fast to over 200 ft on air in the chamber and get them narced, Doc would then convince them their watch had the incorrect time and have them adjust it while at depth. As soon as the crown was screwed back down he'd bring them up fairly fast (just a dry bounce dive, little or no deco) and blow the crystal off. It was one of Doc's favorite tricks...

[gan1hck]

Originally Posted by JohnEaton

Sorry Bandit, I was juggling 4 or 5 things at once, I had a customer that didn't need anything unless he saw that I was busy at the computer in which case he had a dumb question, I just posted when I should not have, please accept my apology.

Here's a little info:





I'll post some more about this soon.






That works too... It also works in reverse... Our Dive Doc (old navy guy) was a sadist... He would take newbies down fast to over 200 ft on air in the chamber and get them narced, Doc would then convince them their watch had the incorrect time and have them adjust it while at depth. As soon as the crown was screwed back down he'd bring them up fairly fast (just a dry bounce dive, little or no deco) and blow the crystal off. It was one of Doc's favorite tricks...

That's HILARIOUS....I used to be a Navy doc...worked with a guy who free dove (from a chamber) at 1000 feet....he had some pretty cool stories...but that wasn't one of them.