GTA
Airguns by Make and Model => Crosman Airguns => Topic started by: Whirligig on February 22, 2017, 06:37:50 PM
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What does the below notification from Crosman mean for other airgun manufacturers who use gas-piston powerplants? Will they need to pay licensing fees? Or worse?
"Nitro Piston 2 Patent Issued To Crosman Corporation
Bloomfield, NY-February 21, 2017. The Crosman Corporation is pleased to announce that the United States Patent and Trademark office has issued a patent for technological components used in the market-leading Nitro Piston 2 break barrel platform.
“The Nitro Piston 2 (NP2) platform was launched at SHOT Show in 2014, landing in the top 10 of the Blue Book of Gun Values innovation roundup and has enjoyed tremendous success in the marketplace ever since,” says Vice President of Marketing & Product Development, Jennifer Lambert. “We are extremely proud to build on Crosman’s history of innovation with the addition of this patent to our stable of proprietary intellectual property.”
The NP2 system has been integrated into Crosman’s premier performance, domestically made Benjamin break barrel lineup. The NP2 platform will also be featured in the new 2017 lineup of air guns featuring all-new SBD (Silencing Barrel Device) technology. SBD’s unique, integrated silencer design reduces the sound of a shot cycle and is three times quieter than standard spring action break barrels delivering the quiet power that air gun consumers have come to expect from Crosman and Benjamin products.
The Nitro Piston 2 system generates 15 percent more speed, 35 percent more power, reduces noise and requires up to ten pounds less cocking force for superior performance.
For more information on NP2 and the air guns produced with the patented technology visit www.crosman.com (http://www.crosman.com)."
Thoughts?
Thanks,
-Whirly
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Without a patent number, you really can't say. I bet it is limited to a very tight design.
Otherwise it would be a useless patent as there is decades of prior art.
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It only prevents other manufacturers from using certain features which make the NP2 unique.
The concept of the gas strut (or NItro Piston) itself are not patented and other manufacturers obviously already use it.
You'd probably have to read the actual patent to see specifically which features are patented. They could include the trigger mechanism or the way the piston is put together.
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domestically made Benjamin break barrel lineup.
I thought all that stuff was made in china
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I am pretty sure the NP2 line is assembled in the USA from globally sourced parts.
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Many of the NP2 parts are U.S. made. Some are out-sourced. It is completely assembled in the USA. The quality is heads and shoulders above the Chinese made B19 platform ones.
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asked this on the crosman page
I don't see any ting new on the piston ? I'ts buttoned, the front buffer on it in front of the piston body and behind the separate head and main seal ? I have a old BSA Meteor V with one ?
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Fantastic power plant. Wish they would couple it with better components like trigger, pivot bolt, etc.
So close to being a game changing break barrel gun...
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This appears to be Crosman's most recently actually granted patent, http://www.freepatentsonline.com/9562738.html/ (http://www.freepatentsonline.com/9562738.html/)
It was granted February 7, 2017 but seems to deal with coil spring powerplants. The announcement might refer to a patent that has been "allowed," but not yet actually granted.
To determine what is covered by a patent, one must look at the claims at the end of the patent. Here is claim 1 of the above patent:
1. An airgun comprising:
(a) a barrel;
(b) a compression tube having transfer port fluidly connected to the barrel;
(c) a compression piston at partially disposed within the compression tube and moveable within the compression tube between a first position and a second position, the compression piston having a piston body and a piston head, the piston head being longitudinally displaceable relative to the piston body during movement from the first position to the second position;
(d) a seal connected to the piston head and forming a sealed interface with an inside surface of the compression tube;
(e) a spring contacting the compression piston, the spring repeatably moveable between a cocked position and a fired position, wherein the compression piston is in the first position in the cocked position of the spring and the compression piston is in the second position in the fired position of the spring; and
(f) a radially expandable bushing connected to the piston body, the bushing radially expanding from a non contacting configuration to a contacting configuration in response to a longitudinal compressive force on the bushing, the longitudinal compressive force corresponding to movement of the spring from the cocked position to the fired position and the radial expansion of the bushing in the contacting configuration sufficient to contact the inside surface of the compression tube.
To infringe or "violate" a patent, resulting in money to the owner and an injunction (stop making) to the infringer, an article, in this case an airgun, must have all of the features listed or itemized in the claim.
Similarly, to be patentable, the claim must list or itemize something that is different from the "prior art," that is, what has been done before.
I have bolded what appear, at a glance, to be the new features in this particular patent. The second feature is described in further detail after the bolding.
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Yes, I know this is old. Just tidying up & adding my 2-cents
TwiceHorn has the correct patent for the NP2 powerplant. The patent shows the original pending date, which is just before the NP2 guns started to appear with their 'Patent Pending' markings. That pending status ended at the same time that the pending markings were removed
Last winter, I downloaded & went over US9562738 with a dual monitor setup so I could both read the description and view the drawings. This usually helps when reading patents, as I tend to get lost with those sort of things!
The most important feature has to do with addressing the tendency of high-power springer pistons bouncing back before the pellet has moved significantly. This 'bounce-back' reduces the peak sustained pressure at the transfer port & adds to the recoil behavior of the gun
The new design splits the piston into two sections. The head of the piston, which is driven by the spring. The spring itself can be either a coiled steel or gas ram. The patent was careful to cover all bases on this. And then the rear section, which is basically the skirt
The spring does not act directly against the skirt, only driving the head. When the piston head begins to rebound from the compression of air, the skirt will continue forwards due to inertia. What happens next is the most interesting part
There's a soft rubber material in between the skirt and head. This material is squished & expands outwards. When that happens, the soft material acts like brake pads on a car. The entire piston assembly is temporarily held stationary, and thus holds the peak pressure long enough to drive the pellet at a higher power level than typical
Tuning for more power means you need to figure out how to get that soft bushing to grab harder. Adding weight to the skirt is one possibility. And making the bushing from something more aggressive is another
And of course, what someone should do is take the piston all the way apart and show the ramp angles, measure the weight of the head & skirt, and try to evaluate the bushing material
The drawings in the patent do not necessarily have the correct angles & dimensions to scale, but I would compare the production parts to those drawings just to be thorough. If that is, I had one of these NP2 power plants
Personally, I'd rather buy a Hatsan 135 in .30 & make a custom NP2 style piston for it. It's my theory that Crosman has dialed down the pressure in their gas ram in combination with this 'Split-Compression Piston', in order to make the gun smoother & easier to cock. This simple change allows the rest of the gun to remain basically unchanged
This appears to be Crosman's most recently actually granted patent, freepatentsonline com/9562738.html
It was granted February 7, 2017 but seems to deal with coil spring powerplants. The announcement might refer to a patent that has been "allowed," but not yet actually granted.
To determine what is covered by a patent, one must look at the claims at the end of the patent. Here is claim 1 of the above patent:
1. An airgun comprising:
(a) a barrel;
(b) a compression tube having transfer port fluidly connected to the barrel;
(c) a compression piston at partially disposed within the compression tube and moveable within the compression tube between a first position and a second position, the compression piston having a piston body and a piston head, the piston head being longitudinally displaceable relative to the piston body during movement from the first position to the second position;
(d) a seal connected to the piston head and forming a sealed interface with an inside surface of the compression tube;
(e) a spring contacting the compression piston, the spring repeatably moveable between a cocked position and a fired position, wherein the compression piston is in the first position in the cocked position of the spring and the compression piston is in the second position in the fired position of the spring; and
(f) a radially expandable bushing connected to the piston body, the bushing radially expanding from a non contacting configuration to a contacting configuration in response to a longitudinal compressive force on the bushing, the longitudinal compressive force corresponding to movement of the spring from the cocked position to the fired position and the radial expansion of the bushing in the contacting configuration sufficient to contact the inside surface of the compression tube.
To infringe or "violate" a patent, resulting in money to the owner and an injunction (stop making) to the infringer, an article, in this case an airgun, must have all of the features listed or itemized in the claim.
Similarly, to be patentable, the claim must list or itemize something that is different from the "prior art," that is, what has been done before.
I have bolded what appear, at a glance, to be the new features in this particular patent. The second feature is described in further detail after the bolding.
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Herm I kinda want to peek inside my trail np2 now.
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I had mine apart last week or so for the first time. The head of the piston was a bit loose so I took it apart and added a little blue locktite to the screw that holds the front to the main piston. I also smeared a very small amount of molly to that red bumper cushion...maybe that was a mistake ?
Edit: Thought it might be of interest, the piston is pretty heavy. I don’t have a scale but definitely heavier than the one in my Vantage np or Hatsan 95.
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Mac, that piston weight is very interesting. The patent is the only info I have on the NP2 piston, so the actual weight of the head & skirt assemblies would be nice to know. I'm assuming you are referring to the complete assembly? But the head weight needs to be heavy enough that it won't rebound too soon & have enough reverse inertia to help squeeze the braking ring. The skirt needs to have only just enough weight that it will continue driving forwards into the braking ring with enough force to squeeze it outwards
Something I would try out is to polish the inner cone & clamping faces that the braking ring is being squished with. In order for the ring to work better, it might be possible for the braking ring to slide across those inner surfaces while tightly clamped
The 'Split-Compression Piston' makes tuning a bit more interesting. Simply adding a friction reducing lube to the outside of the piston, or inside of the compression tube may result in a loss of power. You'll need to have a chrony to know for certain
Buttoning the piston might require supporting the skirt at it's forward end. I think the piston head will be attached solidly enough to the ram that it wont tend to tilt in the bore, thus the rear of the ram is what supports the rear of the piston head. This means the mating surfaces between head & ram should be treated the same as rebuilding a diesel fuel injector - optically flat & open-heart surgery clean! Locktite is a good idea for that
I also think that the braking ring might need to be replaced after some number of shot cycles. So now might be a good time to consider spares
I had mine apart last week or so for the first time. The head of the piston was a bit loose so I took it apart and added a little blue locktite to the screw that holds the front to the main piston. I also smeared a very small amount of molly to that red bumper cushion...maybe that was a mistake ?
Edit: Thought it might be of interest, the piston is pretty heavy. I don’t have a scale but definitely heavier than the one in my Vantage np or Hatsan 95.
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I lined the chamber with super lube and then wiped most of it out so I’m sure I defeated the purpose of the red rubber cushion. I thought it was just a shock absorbing cushion. I really need to get a chrony so I can tell how bad I screw things up lol.
As far as spare parts I believe you have to order the whole piston assembly. I have the parts break down from Crosman and there are no individual part numbers, not even for the seal, only one for the whole assembly. As far as “heavy” I meant the piston itself. The front part with the seal and bumper don’t amount to much. The skirt is buttoned from the factory but not real tightly.
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Buttoned already! That's also very interesting. It wouldn't take much to turn out some new buttons to fit the existing holes, I have a metal lathe so I'm dangerous like that! And Crosman has decided they only needed just the ones at the rear. Possibly the front of the skirt is supported well enough to not touch down?
As for defeating the braking ring, does the gun feel any different? I would guess that if the brake stopped working completely, the gun will recoil much more harshly
I would expect some percentage of the superlube is getting wiped off the compression tube by the braking ring, so if there's a change in braking effect, it'll be somewhere in between full-on & zero
I would also consider measuring the bore of the compression tube on a gun with a very high shot count, to see if the braking ring is wearing a section larger than the rest. If it is, I would like to know just how far back that places the piston from fully bottomed-out. Maybe coating the bore with some machinists dye will show where the braking is taking place
Is there any chance the older NP rams will fit the same as the NP2 ram? I'm betting the gas pressure is higher in the older guns
Looks like I had the wrong idea on how the ram is fitted to the piston, just looking again at the patent drawings, I see the screw goes inside the piston skirt, into the head. The ram is just resting freely against the screw
And the patent does describe those rear buttons, I just hadn't remembered that detail
A few details of interest. The pending status was filed as a 'Provisional Patent Application' on May 10, 2013 in application 61/822,177
Crosman refers to the buttons as 'Tail Guides'
The patent is written to describe the 'spring' as: 'metal coil spring, a pneumatic or a gas spring' & 'metal coil or helical springs, composite or alloy coil or helical springs as well as gas springs or struts'. This means it doesn't matter how a third-party tries to copy the NP2 piston, the patent is specifically not concerned with what type of spring may be used. I would imagine that even a opposed pair of flat leaf springs connected with a length of Spider Line P8 windshield cutout cable (1mm thick, rated for 365lbs, low-friction coating) to drive the piston would be covered by this patent? Maybe even a linear magnetic spring? That would come down to how the intent of the patent can be shown in court
The specific intent of just what the NP2 is about can be seen in this statement: 'The present system can be used in a variety of configurations to reduce deceleration induced vibration during firing of an airgun'
The 'Tail Guides' are described as intended to maintain a concentric orientation of the piston relative to the compression tube so as to both increase efficiency and to reduce the noise of a shot cycle
If anyone wants to get concerned about this patent having undue effect against anyone else, be advised that the 'Tail Guides' are like a rider, and Crosman has been granted the exclusive rights to distributing airguns for sale with such a feature. This patent goes into some extensive detail on the 'Tail Guides', even specifically calling out the name 'Buttons' as included under this patents protection
This patent specifies tail-guides made from Nylon, PTFE and PTFE-coated Nylon. But also including various alloys and metals such as oil-impregnated bronze
The braking ring is described as a 'Bushing'. It can be solid, hollow, webbed, non-homogenous as in multiple over-moldings of differing materials or fluid-filled. The bushing is likely to have a long-wearing outer layer with a lower-cost inner section. The bushing can be made from Nylon or PTFE-coated Nylon, but is more likely to be Polyurethane
The ratio of length or weight of the piston head vs the piston body can be anywhere from 1:20~20:1
The braking effect is described as 'increasing the amount of time that the piston decelerates' and finally slowing to a point where the pressure reached can remain in effect for a much longer time, thus allowing more energy to be transferred to the pellet
I lined the chamber with super lube and then wiped most of it out so I’m sure I defeated the purpose of the red rubber cushion. I thought it was just a shock absorbing cushion. I really need to get a chrony so I can tell how bad I screw things up lol.
As far as spare parts I believe you have to order the whole piston assembly. I have the parts break down from Crosman and there are no individual part numbers, not even for the seal, only one for the whole assembly. As far as “heavy” I meant the piston itself. The front part with the seal and bumper don’t amount to much. The skirt is buttoned from the factory but not real tightly.
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It doesn’t seem much different in the shot cycle sense I “tuned” it, maybe a hair smoother if anything. The red dampening bushing is stiff enough that it seems unlikely to expand under compression enough to grip the chamber. I’m guessing it acts more like a cushion and then could slightly delay rebound. That is just my guess and I could be totally wrong seeing that I’m a complete novice at this stuff.
I thought that I’ve read somewhere on here that the gas struts are not interchangeable between the np and np2 but I’m not 100% sure. I do no that it takes a lot more effort to cock my Vantage np than my Benjamin np2.
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A good book to read on the things that go on inside a springer: The Airgun from Trigger to Target, by the Cardews. Under $25 on ABE Books
They were finding peak pressure reaching up to 1250 PSI, in a spring-piston rifle back in the early 90's
The amount of force acting against the bushing will be much more than you might realize
The results you are getting might suggest the bushing is just a touch too aggressive, if you are certain it's shooting more smoothly
It would be nice to have a high-resolution accellerometer attached to the compression tube, in order to see what changes are happening. That's a back burner project I was looking into. On my shoe-string sized budget, I have to build this sort of thing
It doesn’t seem much different in the shot cycle sense I “tuned” it, maybe a hair smoother if anything. The red dampening bushing is stiff enough that it seems unlikely to expand under compression enough to grip the chamber. I’m guessing it acts more like a cushion and then could slightly delay rebound. That is just my guess and I could be totally wrong seeing that I’m a complete novice at this stuff.
I thought that I’ve read somewhere on here that the gas struts are not interchangeable between the np and np2 but I’m not 100% sure. I do no that it takes a lot more effort to cock my Vantage np than my Benjamin np2.