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New STC kit - Mongoose

Thread Status: Hello , There was no answer in this thread for more than 60 days.
It can take a long time to get an up-to-date response or contact with relevant users.
T

tromic

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STC web: https://www.stcitalia.net/english/products.html

1592461823774


I suppose it might be similar to Tomba on this image..?
 
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popgun pete

popgun pete

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I see that it is in titanium. Given the length of time the Tomba thread has been up they have probably copied you or one of your products that someone purchased and enabled them to examine it.
They have even taken out a patent on it.
STC Mongoose patent

STC Mongoose patent 2
 
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popgun pete

popgun pete

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Interesting the patent was published in 2011, but they sat on it until now. This has the effect of running out the time period for objections.
Mongoose
 
Diving Gecko

Diving Gecko

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Hmmm, patents...

I am a photographer who relies on my copyright protection to make a living and thus, I respect and understand the need to protect intellectual property but my basic feeling is that the patent system and the fundamental idea behind is being misused in some cases. I doubt that every national patent office has the resources to check globally if a given idea has been presented anywhere else in the world at any time before - so, what happens is that unwarranted patents are being granted. To the point where someone can basically steal ideas and patent them in their own or other countries.

Supposedly, STC went after Devoto at some point - if you are to believe Dima who was asked for advice on the matter. STC holds a/some patents for vac muzzles and Dima's point was that there's a Russian 1977 patent for a vac muzzle and that even UBL and others likely made vac muzzles before STC. Whether the STC patent is a very, very specific one or a "wider" one, I don't know. But yeah, to me the patent system is flawed. But I guess, like the UN, it's the best we have...

On a related note, I have heard stories of Chinese companies taking up brand/logo registration in China that are blatant rip offs of Western brands. This happens because the Chinese officials don't check thoroughly enough and the Western companies don't know of it happening and thus, don't know of the "objection period". And fighting it after the fact in a Chinese court of law is not easy though it should sound like a slam dunk case.
 
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popgun pete

popgun pete

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If someone has a later patent on something that you made earlier then you can claim it as “prior art” if there is documentary evidence of it, say here on Deeper Blue which may have been read by thousands. Thus while they can prevent you commercializing it they cannot stop you making it. Also patents only hold in the countries in which they are registered. Note that multiple patents in many countries have been taken out for the “Dreamair”, but fighting copyists is expensive and unless you have one in China you are not entirely protected. And unless you are Chinese enforcing in China is probably as likely as running a snowball machine in Hell.
 
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Diving Gecko

Diving Gecko

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Thanks for Patent information Davide, but I do not see anything similar to Mongoose in that patent...?

Nah. It was just me ranting about the system being flawed... Point was that people can misuse the system.


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T

tromic

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Here are some dates from the Patent:
-Priority: 23.12.2008 IT LU20080022
-Date of filing: 21.12.2009
-Date of publication of application: 30.06.2010 Bulletin 2010/26
-Date of publication and mention of the grant of the patent: 14.12.2011 Bulletin 2011/50

But I repeat, there is nothing similar in Patent to Mongose-X or any Tomba designs.

I was started to think about vacuum solution in 2008., in time of Mamba, and this was the first attempt in Jan 30. 2009. ready to be tested in summer that year:

This was what I had on 14.12.2011.:

It seems to me that STC - Mongoose-X is really a copy of Tomba7N3 but with metal elements in reverse order, and made in titanium instead in stainless steel.
One huge difference between actual TombaX (Tomba700X,...) and Mongoose-X is that TombaX has tiltable muzzle insert that makes loading of the shaft fluent even when bowing the shaft. That insert also makes possible to have very tight gaps between the shaft and the slider and also to have OR of very small cross section on the shaft, like 1 - 1,5 mm not losing the vacuum.

But maybe not..., it is more similar to Mamba. The front titanium part serves to protect the plastic slider from damage on collision, I suppose..
Also I would say that the possibility of damaging/shaving the OR is maybe an issue..? It was the main reason I did not actually realized Tomba7N3.
That OR must be radially compressed and inserted into the titanium housing carefully. That is not problem during loading the speargun but might be a problem after the shot when the line pulls back the slider or the fish start pulling the shaft.


1592578682906
 
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popgun pete

popgun pete

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Here are some dates from the Patent:
-Priority: 23.12.2008 IT LU20080022
-Date of filing: 21.12.2009
-Date of publication of application: 30.06.2010 Bulletin 2010/26
-Date of publication and mention of the grant of the patent: 14.12.2011 Bulletin 2011/50

But I repeat, there is nothing similar in Patent to Mongose-X or any Tomba designs.

I was started to think about vacuum solution in 2008., in time of Mamba, and this was the first attempt in Jan 30. 2009. ready to be tested in summer that year:

This was what I had on 14.12.2011.:

It seems to me that STC - Mongoose-X is really a copy of Tomba7N3 but with metal elements in reverse order, and made in titanium instead in stainless steel.
One huge difference between actual TombaX (Tomba700X,...) and Mongoose-X is that TombaX has tiltable muzzle insert that makes loading of the shaft fluent even when bowing the shaft. That insert also makes possible to have very tight gaps between the shaft and the slider and also to have OR of very small cross section on the shaft, like 1 - 1,5 mm not losing the vacuum.
Probably STC have not got around to copying that tilt aspect yet.
 
T

tromic

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I was thinking about how it was supposed to work Mongoose capsule. If it should be closed all the time than it would work like LG solution with only difference being the placement of sealing O-ring, because in LG it is inside the slider. If the O-ring would be pushed out on shot than it would work like old Mamba. The only difference between this two modes would be due to the friction forces and water pressure.
 
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popgun pete

popgun pete

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Figure no.3 from the patent is rather misleading as it does not depict the Mongoose third option accurately. The "O" rings shown are in the wrong places and they also don't show the "O" ring or seal in the muzzle body that the rear titanium cylinder seals onto when the gun is cocked to shoot. In fact it is a hopeless depiction. You are right, the titanium two piece structure is a type of Mamba arrangement, but has a separate line slide in front of it.
MONGOOSE X
 
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tromic

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Figure no.3 from the patent is rather misleading as it does not depict the Mongoose third option accurately. The "O" rings shown are in the wrong places and they also don't show the "O" ring or seal in the muzzle body that the rear titanium cylinder seals onto when the gun is cocked to shoot. In fact it is a hopeless depiction. You are right, the titanium two piece structure is a type of Mamba arrangement, but has a separate line slide in front of it.
View attachment 56293
Yes, and I would say that it would work unstable. On depth over, say 10 m, it would work like LG slider and below 5 m maybe like Mamba pushing the O-ring out from the capsule because the water pressure would be lower, but it also depends on the tightens of the front titanium part that closes the capsule...
 
popgun pete

popgun pete

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In fact citing their patent on this new set of options is smoke and mirrors because this patent relates to their original STC-X muzzle if you look at the photos of it.
STC X Power muzzle schematic assmbly
STC X Power muzzle

The two new options are a sort of nozzle seal (without the nozzle?) and this Mongoose system which is a sort of Mamba. Both are so you can use tail ended shafts instead of the bare tail or nude shafts, which means that you can attach your shooting line to the rear of the shaft as the line slide moves back as the shaft departs the muzzle. The STC-X muzzle needs front tied spears as are used on the STC equipped Sporasub "One Air".
STC Gasket seal

My guess is the nozzle on this D.S.S. seal pops out like one of those silicone funnels which store flat until you use them and when you reload the shaft tail it pushes the nozzle back to fold in on itself. If so flexing back and forth will wear it out, but may be OK if you replace it periodically.
 
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Diving Gecko

Diving Gecko

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In fact citing their patent on this new set of options is smoke and mirrors because this patent relates to their original STC-X muzzle if you look at the photos of it.
View attachment 56294View attachment 56295
The two new options are a sort of nozzle seal (without the nozzle?) and this Mongoose system which is a sort of Mamba. Both are so you can use tail ended shafts instead of the bare tail or nude shafts, which means that you can attach your shooting line to the rear of the shaft as the line slide moves back as the shaft departs the muzzle. The STC-X muzzle needs front tied spears as are used on the STC equipped Sporasub "One Air".
View attachment 56296
My guess is the nozzle on this D.S.S. seal pops out like one of those silicone funnels which store flat until you use them and when you reload the shaft tail it pushes the nozzle back to fold in on itself. If so flexing back and forth will wear it out, but may be OK if you replace it periodically.

If the DSS seal is their regular one I think it’s rather solid and can’t be turned inside out or folded in on itself. The pic doesn’t show it well but the relief cut at the front is rather shallow. The rest of the seal is quite chunky and solid. I’ll try to pop the one in my One Air out and take some snaps at some point.


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popgun pete

popgun pete

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Just looking at my “One Air” it looks like that rubber washer is flat on the other side, so it is just a packing arrangement. The number two option must be that rounded step spear tail that I had forgotten about, not the rubber washer. They could have used two ”O” rings in that location as the figure 3 seems to show, but that would not let even a rounded step shaft tail through. Shaft that came with my "One Air" is a 7 mm with a "nude" tail as they refer to it.
One Air muzzle detail from the manual

Muzzle set up

The gun came with two extra rubber gaskets and guide bushings, so I guess they are the two other sizes as I never removed them from their packaging bag. 7 mm is OK, but 6.5 mm and 6.75 mm are a bit on the slim size if you use long shafts.
 
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Diving Gecko

Diving Gecko

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Just looking at my “One Air” it looks like that rubber washer is flat on the other side, so it is just a packing arrangement. The number two option must be that rounded step spear tail that I had forgotten about, not the rubber washer. They could have used two ”O” rings in that location as the figure 3 seems to show, but that would not let even a rounded step shaft tail through.
Ah, sorry forgot you had one, haha.
Yes, flat on the rear side. Shallow relief at the front to form a bit of a lip which can open and let water out when inserting the shaft.

[EDIT] Saw your pic of the manual now and the cut is not as shallow as I recall. Hmmm, I need to stop trusting my memory too much;)
 
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T

tromic

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The spear with Mongoose kit can be loaded under water. I asked that question on Facebook and that was the answer. I suppose the cuff seal is also the part of the configuration...? What is than the purpose of the O-ring in the muzzle, maybe just to support the titanium part, but not to seal from outside.
 
T

tromic

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The spear with Mongoose kit can be loaded under water. I asked that question on Facebook and that was the answer. I suppose the cuff seal is also the part of the configuration...? What is than the purpose of the O-ring in the muzzle, maybe just to support the titanium part, but not to seal from outside.

This is what one need to bye to have functional STC kit with Mongoose. It seems that the cuff seal is not necessary...
 

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T

tromic

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Aug 13, 2007
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Figure no.3 from the patent is rather misleading as it does not depict the Mongoose third option accurately. The "O" rings shown are in the wrong places and they also don't show the "O" ring or seal in the muzzle body that the rear titanium cylinder seals onto when the gun is cocked to shoot. In fact it is a hopeless depiction. You are right, the titanium two piece structure is a type of Mamba arrangement, but has a separate line slide in front of it.
View attachment 56293
This STC kit is the most similar to Tomba7N7...

1663439011099
 
popgun pete

popgun pete

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The advantage of all the vacuum seal anchored in the muzzle guns is that they can be muzzle loaded underwater. As soon as the spear tail can push the piston back then space opens up for the water already in the muzzle opening to be sucked into the inner barrel and then the muzzle seal taking up prevents any further ingress of water into the barrel. If it does not seal then water will fill the entire inner barrel surrounding the spear. Sealed sliders that seal both on the muzzle to slider body interface and on the spear have the problem of any hydraulic lock stopping the slider fully engaging into the muzzle seal, but the slider can be sucked in as the piston moves if a slight drag by the spear seal pulls the slider back into the fully sealed position. If the slider body does not take up on the muzzle seal then the inner barrel fills with water as it courses through any annular gap.

The muzzle anchored vacuum seal guns were a hassle to change or inspect the vacuum cuff/seal until the removable muzzle nose cap guns appeared and virtually all these guns now work this way. The nozzle type seals have the ability to blow open by the rubber nozzle stretching when trapped water has to get out if any water leaked in which exceeded the spear tail insertion starting volume capacity, the washer type seals with less capability to spread will not let excess water out so easily. The nozzle type seal has more flexibility to let the spear tail stop out by stretching the nozzle, but both seal types can be damaged by burrs setting up on the spear tail stop's leading edge as the spear leaves the gun which will then tear up the sealing rubber surfaces.

As muzzle loading is done at a relatively slower rate compared with the shaft exit velocity the sealing lips then have more time to conform to the changing diameters as the spear tails are pushed through them. A tiny amount of water briefly leaking in which elevates the water volume trapped inside the inner barrel above the spear tail insertion starting volume capacity has the advantage of blowing the nozzle open just before the spear tail stops diameter actually hits it, but this cannot be relied on to happen with every shot.
Seal
 
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