Stephens Brass Trombones

[thepianoman04]

I'm currently on the market for a medium bore trombone and haven't had a chance to try a Stephens Brass Trombone yet and will be going to MidWest this year but Steve Shires won't be there.

Just curious if anyone out there that went to ITF at UCA was able to try the Stephens Brass Trombones (medium or large) and try to explain what differences they heard compared to say a Shires, Edwards, M&W, etc?

I get it is subjective but I was just curious if it has more similarities to a Shires or is it a completely different animal?

Appreciate any insight anyone that's tried them can offer.

Thanks!

[WilliamLang]

Hi there!

I was at ITF this summer and was blown away by Stephens Horns. I ended up buying one on the spot, and felt that the quality of the instrument was the highest in the room. (I also really enjoyed the Hagmann Thein Tenors, but the Stephens felt closer to my voice.)

The one I purchased was a large bore Mt. Vernon copy, and in my opinion, had all the wonderful colors of Shires, but better slotting (specifically it feels like Stephen has figured out something new with the slide and lead pipes.)

[thepianoman04]

Now this is what I like to hear!

Appreciate your insight and can’t wait to play one myself.

Love hearing other’s stories/thoughts.

Hi there!

I was at ITF this summer and was blown away by Stephens Horns. I ended up buying one on the spot, and felt that the quality of the instrument was the highest in the room. (I also really enjoyed the Hagmann Thein Tenors, but the Stephens felt closer to my voice.)

The one I purchased was a large bore Mt. Vernon copy, and in my opinion, had all the wonderful colors of Shires, but better slotting (specifically it feels like Stephen has figured out something new with the slide and lead pipes.)

[TromboneConcerto]

I compared it with my Shires (which is an old one, made by Steve before he left the company) and it felt nearly the same. I wasn't blown away, but I liked it a lot- holding out for an Axial valve version.

[Spemrick]

I have the mt Vernon inspired horn on order through Steve that should be ready in a few months. Will try to post first impressions when I get it. Looking forward to it.

[thepianoman04]

Exciting! Would definitely like to hear your thoughts & see photos once you have it. I’m probably a few months behind you now that I just put my name on the list.

I ordered a medium bore (.525) setup with a 2 piece red brass 8” bell with a yellow slide and nickel end crook with his Caidex valve in the satin/brush finish & a Marcus Bonna case.

So excited to see & play mine!

I have the mt Vernon inspired horn on order through Steve that should be ready in a few months. Will try to post first impressions when I get it. Looking forward to it.

[thepianoman04]

Yea, I could see how you being comfortable with your Shires (I assume made in the early days also by Steve) that his newer horn is similar yet different. I’m sure he’s learned things along the way and hopefully bodes well for us Shires newbies who’ve ordered his new horns with these improvements.

I’ve only had one Shires large bore and was a great horn but even his small bore horns had some quirks with the way they played and sold them all until settling on my Lawler Model 2R. Taking the chance on Steve’s medium bore as I’m really wanting a custom built horn and there are only a few good horn makers out there like Steve that have been doing it so long & still build horns from top to bottom so well.

Thanks for sharing!

I compared it with my Shires (which is an old one, made by Steve before he left the company) and it felt nearly the same. I wasn't blown away, but I liked it a lot- holding out for an Axial valve version.

[Dennis]

I compared it with my Shires (which is an old one, made by Steve before he left the company) and it felt nearly the same. I wasn't blown away, but I liked it a lot- holding out for an Axial valve version.

I would be surprised to see Steve equipping his horns with axial flow valves, because he was never a fan of the axial flow valve (even though he made the best examples of it until the Olsen version came out). He developed each of his valves (the Shires rotary, the Tru-bore, and the dual-bore) to provide what he saw as better alternatives to the axial flow valve.

Yes, he made horns equipped with axial flow valves while at Shires, but that was what the market demanded. I don't have the impression that the market is demanding axial flow valves the way it did when S.E. Shires Co. was a new player.

[norbie2018]

Directly from the website: "We will offer Axial flow valves, as well as a variety of bell and slides in different weights, and material."

[Dennis]

Directly from the website: "We will offer Axial flow valves, as well as a variety of bell and slides in different weights, and material."

Color me surprised.

[GabrielRice]

Axial flow valves definitely have their place, and there are still many players who prefer them.

[Dennis]

I didn't intend to get the valve wars re-started. I'm aware that axial flow valves have a place. In fact, one of those places is on my bass.

Given his work to find alternatives to axial flow valves and his fairly low production rate I'm a little surprised that he is using (or will use) them, and I'm curious as to whose valves he uses.

[BoomtownRath]

I didn't intend to get the valve wars re-started. I'm aware that axial flow valves have a place. In fact, one of those places is on my bass.

Given his work to find alternatives to axial flow valves and his fairly low production rate I'm a little surprised that he is using (or will use) them, and I'm curious as to whose valves he uses.

3

He uses Willson valves, Rotax and Caidex.

[JeffBone44]

Axial flow valves definitely have their place, and there are still many players who prefer them.

Yes, that's true. I just got axial flow valves for my Shires bass.

[RJMason]

15 months later: Wondering if anyone with a Stephens trombone can offer an update on how they are playing and performing in professional settings thus far?

[thepianoman04]

15 months later: Wondering if anyone with a Stephens trombone can offer an update on how they are playing and performing in professional settings thus far?

I can’t really speak to playing mine in any professional settings but I still love mine. It does everything I need it to do, slots well and sounds like I’m playing a large bore while feels & plays like a medium bore. (because it is) lol

Assuming this is Ray, let me know when you’ve got some free time and I’ll let you play test mine.

-Lance

[WilliamLang]

15 months later: Wondering if anyone with a Stephens trombone can offer an update on how they are playing and performing in professional settings thus far?

Still love mine - works so well for what I do. Students and other pros that have tried it are surprised by the open feeling on it, and a lot of them love the Caidex valve in particular.

[Sesquitone]

Students and other pros that have tried it are surprised by the open feeling on it, and a lot of them love the Caidex valve in particular.

Just a small (but important) typographical point, CAIDEX (in all caps) is an acronym:
Constant-Area Internal Ducts of Elliptic Cross Section (with the CS replaced by X for easy pronunciation).

For a large bore size in a compact casing, the sound-path in each intact duct gets 'squeezed' through the middle section of the valve. With the (continuously varying) elliptic cross sections of the CAIDEX, starting from a circular cross section at the inlet port, the major axis of the ellipse is gradually expanded along the sound-path through the first half of each duct to exactly compensate for the necessary squeezing of the minor axis, and then relaxed again through the remaining half back to circular, guaranteeing constant cross-sectional area of the sound-path, as seen below (showing relative areas at various sections through the first half of one duct). It's this constant-cross-sectional-area sound-path (with no sharp changes in direction) that provides the 'open feeling'.

With a lipped-tube rotor design—with the natural venting guaranteeing silent transition (no 'popping')—it is essential to have very precise alignment. This is achieved on the CAIDEX by having individually adjustable stops. And a 'see-through' end-cap so that the player can check, at a glance, that the witness marks are, indeed, precisely aligned.

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[Spemrick]

After picking up my Stephen’s and using it exclusively for large bore work for a couple of months, I’m able to give some thoughts on the instrument and how it plays for me. First the specs. The horn has a lightweight gold brass bell, yellow tuning slide, yellow hand slide with nickel tenor crook, and comes with the typical three lead pipes. This is Steve’s Bach inspired instrument The horn is lacquered.

This horn is extremely free blowing. On my Shires gear. I generally gravitate towards the number two size lead pipe, but on this horn I’m playing Steve’s tightest lead pipe at the moment. So far I’ve used it in orchestra and large brass ensemble, and in both rehearsals and performances the horn has worked very well, blending easily with colleagues, while at the same time being really easy to hear. This is probably the best feeling rotor I’ve ever felt, and sound quality between the B-flat and the F side of the horn is very easy to control. The slide is spectacular, what you would expect from Steve. So far I love playing this horn, it can do way more than I’m capable of at the moment. Workmanship overall is spectacular. Here are a few pictures of the instrument.

[Tbarh]

After picking up my Stephen’s and using it exclusively for large bore work for a couple of months, I’m able to give some thoughts on the instrument and how it plays for me. First the specs. The horn has a lightweight gold brass bell, yellow tuning slide, yellow hand slide with nickel tenor crook, and comes with the typical three lead pipes. This is Steve’s Bach inspired instrument The horn is lacquered.

This horn is extremely free blowing. On my Shires gear. I generally gravitate towards the number two size lead pipe, but on this horn I’m playing Steve’s tightest lead pipe at the moment. So far I’ve used it in orchestra and large brass ensemble, and in both rehearsals and performances the horn has worked very well, blending easily with colleagues, while at the same time being really easy to hear. This is probably the best feeling rotor I’ve ever felt, and sound quality between the B-flat and the F side of the horn is very easy to control. The slide is spectacular, what you would expect from Steve. So far I love playing this horn, it can do way more than I’m capable of at the moment. Workmanship overall is spectacular. Here are a few pictures of the instrument.

What kind of rotor is that ?

[Spemrick]

That is Steve‘s own design, I think he told me I got the third one give or take. It’s very nice.

[Blabberbucket]

That is Steve‘s own design, I think he told me I got the third one give or take. It’s very nice.

It is not Steve's design. That valve was patented by Brian Phillip Leonard in 1996 and expired in 2016. https://patents.google.com/patent/US5900563A/en

It is, more or less, a traditional rotor with a slightly altered routing and port placement.

[Burgerbob]

Isn't it a Bosc?

[Briande]

That is Steve‘s own design, I think he told me I got the third one give or take. It’s very nice.

It is not Steve's design. That valve was patented by Brian Phillip Leonard in 1996 and expired in 2016. https://patents.google.com/patent/US5900563A/en

It is, more or less, a traditional rotor with a slightly altered routing and port placement.

I find it crazy after all these years (50+) we are still coming up with new designs for what one would assume is a simple rotary valve!

[Spemrick]

I thought that’s what Steve told me but I definitely could be wrong.

[RJMason]

That is Steve‘s own design, I think he told me I got the third one give or take. It’s very nice.

It is not Steve's design. That valve was patented by Brian Phillip Leonard in 1996 and expired in 2016. https://patents.google.com/patent/US5900563A/en

It is, more or less, a traditional rotor with a slightly altered routing and port placement.

Steve told me it’s his new rotor design and Terry Warburton’s son is producing it to his exact specifications. Have you gotten into a Stephens rotor to see if it’s the same as this old patent? Do you think Steve is lying? Are you Brian Phillip Leonard? Who cares if it plays well? Lol

[Spemrick]

The valve does play great.

[Sesquitone]

It is not Steve's design. That valve was patented by Brian Phillip Leonard in 1996 and expired in 2016. https://patents.google.com/patent/US5900563A/en

It is, more or less, a traditional rotor with a slightly altered routing and port placement.

Steve told me it’s his new rotor design and Terry Warburton’s son is producing it to his exact specifications. Have you gotten into a Stephens rotor to see if it’s the same as this old patent? Do you think Steve is lying? Are you Brian Phillip Leonard? Who cares if it plays well? Lol

So, let me clear up a few things. First, I am Brian Phillip Leonard, commonly known as "Benny"—a schoolboy nickname, after the famous world-champion boxer. [My dad was a champion amateur boxer; in my teens, I used to help him coach at a local Boy Scouts' club in Melbourne, Australia.] The patent in question is not the 1996 patent (in which the rotor was not vented). It is from 2000: Low Friction Vented Rotary Valve for Brass Wind Instruments. It is an Unsymmetrical Lipped-Tube Rotary Actuator, with a 90º angular throw. So, naturally, I call it the ULTRA valve. The knuckles and intact rotor ducts are of fully circular cross-section all the way through—a natural extension of the sound-path tubing from the slide, continuously through into the gooseneck. The unsymmetrical design eliminates one (unnecessary) additional 45º bend. Hence the 'free-blowing' performance. The venting eliminates any possibility of 'popping' in transition between active orientations. Other than the duct walls, lips and bearings, there is no 'non-functional' mass. This reduces rotational inertia by about 60% relative to comparable conventional rotaries, resulting in a very fast (but firm) mechanical action.

In the early 2000s, Jupiter was very interested in the ULTRA valve and we built an XO/ULTRA prototype (with a dual-bore slide matched to the 14.3 mm ULTRA valve and attachment tubing) that was highly praised by all professional players who tried it. But, ultimately, after several years of evaluation, top management in Taiwan 'nixed' the project due to 'budget constraints'.

Several years ago (while the patent was still in effect—it expired in 2020), Cristian Bosc contacted me to enquire whether his new design might infringe on the patent. Although his valve (also of unsymmetrical design) has some similarities, its 72º throw makes it enough different that my patent attorney determined that it was not an infringement.

In a sketch, below, I show the difference between the ULTRA valve and a conventional (unnecessarily symmetric) rotary valve. Note in the top-left figure how the rotor ducts and casing knuckles do not have to line up for the inactive path. Also notice the necessary 'squeezing' of the sound-path through the central portion of the conventional rotor.

The CAD picture shows the ULTRA rotor; the 'straight' portion of the duct is facing straight out.

The next sketches (from the 2000 patent) show how the air-flow is not blocked when the rotor is transitioning between active orientations.

The next couple of photos show an actual ULTRA valve in its slide-alone and attachment-engaged orientations. You can see immediately from these photos the 'natural extension of the sound-path tubing' mentioned above. Note my preferred orientation of the valve—the 'straight' portion acts as the inlet to the attachment. I find that this makes for a more 'streamlined' wrap geometry.

Steve Shires contacted me in the middle of last year to confirm that all relevant patents on the ULTRA valve had indeed expired. [They had.] And he mentioned that he was interested in having Warburton manufacture a valve with this unsymmetrical geometry for use with his new line of 'Stephens' trombones. As an option to the CAIDEX valve, produced by Willson in Switzerland (of which I also happen to be the conceptual designer). Steve's preferred orientation is the opposite of mine. It doesn't make any acoustical difference, of course. (See next photos, compared with an ULTRA on a Conn 88H). Plus a couple more photos of ULTRA valves (on a Bach 42B) and (the original prototype of the) Jupiter XO/ULTRA. Note that, with my preferred orientation of the valve, the toggle-arm rotates in the opposite direction from the way Steve's does. This accounts for the 22.5º 'off-horizontal' orientation of the bumper stops.

I trust this clears up any confusion about who designed what and when which patent went into effect and subsequently expired. I'd be happy to answer any further specific questions. For example, the CAIDEX is a totally different concept, incorporating continuously varying elliptical cross-section, exactly maintaining constant cross-sectional area, in a very compact casing (compatible with the Willson Rotax casing). Like the ULTRA valve, it also has individually adjustable bumper stops (something that is of interest on another thread). And the CAIDEX has a 'see-through' end-cap so that the player can check, at a glance, that the witness marks for the rotor stops are precisely aligned, which is even more essential than usual (because of the lipped-tube geometry).







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[Bach5G]

24 years of patent protection doesn’t seem like very much.

Is anyone other than Warburton producing these?

[Posaunus]

Steve told me it’s his new rotor design and Terry Warburton’s son is producing it to his exact specifications. Have you gotten into a Stephens rotor to see if it’s the same as this old patent? Do you think Steve is lying? Are you Brian Phillip Leonard? Who cares if it plays well? Lol

So, let me clear up a few things. First, I am Brian Phillip Leonard, commonly known as "Benny" ...
The patent in question is not the 1996 patent (in which the rotor was not vented). It is from 2000: Low Friction Vented Rotary Valve for Brass Wind Instruments. It is an Unsymmetrical Lipped-Tube Rotary Actuator, with a 90º angular throw. So, naturally, I call it the ULTRA valve.

Benny,

Thanks for the clarification. Though I will never be able to justify purchasing a Stephens trombone, I am sure that this is a superb valve (Steve wouldn't settle for anything less) - and I'd love to play it.

Just a random question: Since you were the conceptual designer for both the ULTRA valve and the CAIDEX valve, which of the two would you install on a new trombone (everything else being equal and legal)? Or are they virtually equivalent, for all "practical" purposes? [Or have you conceived of something even better?]

[Sesquitone]

24 years of patent protection doesn’t seem like very much.

Is anyone other than Warburton producing these?

It's actually 20 years, which is fairly normal. I'm not aware of any other manufacturers producing 'ULTRA-like' valves. I forgot to mention that in the mid-1990s (before either of the patents) René Hagmann built the original ULTRA prototypes for me—a dozen in different bore sizes and knuckle geometries. Using curved tubes threaded through a hollow cage, similar in technique to his own three-duct design. I tried to get René to produce the ULTRA valves commercially, but he was too busy with his own valves (plus his other tech work and music-shop business). A couple of decades later, Dr Morteza Vatani, a recent PhD graduate in robotics from The University of Akron, where I used to teach (in Mechanical Engineering), coordinated with me and took my rough sketches and equations and turned them into beautiful CAD pictures, the programs for which we then used to produce 3D-printed ULTRA rotors to fit into the 'Hagmann' casings (as shown in the photos, previously). The 3D printing is slightly oversized in 'wax'; and then the metal rotor is cast using the lost-wax process; and then the rotor is lightly machined to bring everything onto centre; then lapped into the casing. Mr Hagmann again kindly did all the latter processes for me. Dr Vatani is my co-designer of the CAIDEX valve.

I should perhaps point out that in my (not-unbiassed) opinion, the ULTRA valve and CAIDEX valve have very similar acoustic properties. The main difference is that the CAIDEX casing is more compact; and it can take even larger bores than the ULTRA—up to 15.2 mm (suitable for large-bore bass trombones)—all within a standard 'Rotax' casing. And, of course, CAIDEX valves (with their individually adjustable bumper-stops and see-through end-cap) are available commercially from Willson. [If anyone wants to know.]

[Sesquitone]

So, let me clear up a few things. First, I am Brian Phillip Leonard, commonly known as "Benny" ...
The patent in question is not the 1996 patent (in which the rotor was not vented). It is from 2000: Low Friction Vented Rotary Valve for Brass Wind Instruments. It is an Unsymmetrical Lipped-Tube Rotary Actuator, with a 90º angular throw. So, naturally, I call it the ULTRA valve.

Benny,

Thanks for the clarification. Though I will never be able to justify purchasing a Stephens trombone, I am sure that this is a superb valve (Steve wouldn't settle for anything less) - and I'd love to play it.

Just a random question: Since you were the conceptual designer for both the ULTRA valve and the CAIDEX valve, which of the two would you install on a new trombone (everything else being equal and legal)? Or are they virtually equivalent, for all "practical" purposes? [Or have you conceived of something even better?]

I think I may have just answered this in response to Bach5G. And yes, I find that they are (acoustically) 'virtually equivalent, for all "practical" purposes'. And yes, I am (always) working on (what I hope will be) 'something even better', in order to 'advance the state of the art'.

By the way, if anyone is interested in more details of how the CAIDEX valve 'works', contact me at my office email, below (not the 'family' email listed in my profile), and I'll be happy to send along an electronic copy of a little 'Booklet' explaining the variable-elliptic geometry and other features, compared with standard rotaries.

[email protected]

[RJMason]

This is so awesome, thank you for your replies and your work Benny!

[Spemrick]

Yes, that is great information Benny, and hopefully clears up any confusion. Thank you for that.

[Blabberbucket]

It is not Steve's design. That valve was patented by Brian Phillip Leonard in 1996 and expired in 2016. https://patents.google.com/patent/US5900563A/en

It is, more or less, a traditional rotor with a slightly altered routing and port placement.

Steve told me it’s his new rotor design and Terry Warburton’s son is producing it to his exact specifications. Have you gotten into a Stephens rotor to see if it’s the same as this old patent? Do you think Steve is lying? Are you Brian Phillip Leonard? Who cares if it plays well? Lol

I don't doubt that it plays well. There is a reason Steve has been a renowned repairman and manufacturer for as long as he has.

With that said, I think there is also value in truth and transparency in manufacturing. Thanks to "Benny"s information, we are able to see that Steve is well aware of previous patent claims on this type of valve and even contacted the original designer to be sure that the patent claims were no longer enforced, clearly because this valve is entirely derivative of the original design.

People can say anything they want. I wrote "Don't Stop Til You Get Enough." Are you Michael Jackson or Quincy Jones? Do you think I'm lying?

So... No, I am not the designer. No, I have not seen the internals of this newly manufactured valve. It is great news that these horns play very well - we all want horns that play exceptionally well.

But please do not misrepresent the reality of the valve design out of pure loyalty to the builder of your instrument.

[RJMason]

But please do not misrepresent the reality of the valve design out of pure loyalty to the builder of your instrument.

Im not representing anything, don’t even have a Stephens horn (yet?). You came in mad hot “this is not Steve’s design”. Without Benny’s backstory and context to help your comment it came off as speculative. Luckily, now we all know. Context is king. Dig?

[Blabberbucket]

Im not representing anything, don’t even have a Stephens horn (yet?). You came in mad hot “this is not Steve’s design”. Without Benny’s backstory and context to help your comment it came off as speculative. Luckily, now we all know. Context is king. Dig?

A patent from '96 showing a design nearly identical to the valve shown in posts here is "speculative"? Dig, for sure.

[BGuttman]

A patent runs for 20 years. So a 1996 patent becomes public domain in 2016. It's now 2024. Steve is perfectly within his rights to use the teachings of the patent.

[Blabberbucket]

A patent runs for 20 years. So a 1996 patent becomes public domain in 2016. It's now 2024. Steve is perfectly within his rights to use the teachings of the patent.

I absolutely agree with your statement.

That does not mean that he created it.

[RJMason]

Im not representing anything, don’t even have a Stephens horn (yet?). You came in mad hot “this is not Steve’s design”. Without Benny’s backstory and context to help your comment it came off as speculative. Luckily, now we all know. Context is king. Dig?

A patent from '96 showing a design nearly identical to the valve shown in posts here is "speculative"? Dig, for sure.

If you post diagrams of old internals, yet haven’t seen the internals of the new joint, then yes? lol either way case closed.

[Sesquitone]

Just to be clear, my 1996 patent was indeed for an unsymmetrical rotary valve. The prototype design still had a 90º angular throw; the rotor consisted of a hollow barrel with two tubes threaded through--one with a 90º turn, the other with a 45º turn. It was not vented--and the prototypes (built by René Hagmann) had severe "popping" problems. [Conventional (symmetrical) rotary-valve rotors turn the sound-path through 90º in both channels. Because the channels are "open" (as opposed to intact ducts), allowing continuous air-flow in intermediate orientations, popping problems are minimised.]

Meanwhile, I had vented an early version of the Rotax rotor that did have intact ducts milled through a solid block--using a Dremel tool and small hand files to produce a "lipped-tube" design. This eliminated popping problems entirely in the Willson tenor it was installed in. [See Figure 16 of the later patent from 2000.]

So I sent all 12 ULTRA prototypes back to Mr Hagmann and he scavenged away most of the barrel material to produce the lipped-tube design--with the desired effect: no sign of popping.

This was the basis of my 2000 patent. The lipped tubes provide natural venting, while reducing non-functional mass (i.e. all mass except that in the lipped-tubes and bearing components is eliminated)--thereby drastically reducing rotational inertia and frictional surface area in contact with the casing.

As I mentioned earlier, we later used 3D-printed/cast rotors (cast slightly oversized then "cleaned-up" by subsequent machining of the outer diameters). [By contrast, the (symmetrical) CAIDEX rotor is produced entirely by CNC machining.]

The main similarity of the Stephens/Warburton valve (to my 2000 patent) is it's unsymmetrical geometry--again turning the sound-path through 90º in one duct and only 45º in the other. Steve prefers to install it the other way around from how I conceived it--this also means that the toggle-arm rotates in the opposite direction from that on the ULTRA valve (as seen in the comparative pictures, below).

Other than the fact that there must be one 90º turn and one 45º within the rotor--and that it must be vented (otherwise there would be intolerable popping)--I have no further knowledge of the detailed design of the Warburton-produced rotor.



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[Posaunus]

To be even clearer, the enforceable part of a Patent is not the drawings or the description of the invention, it is the specific wording in the Patent Claims. A "competing" device may share many of the features of other previously patented inventions, but unless any of those features violate the specific Claims of a Patent, there is no infringement.

Benny Leonard does not seem to mind that the Stephens valve, though differently assembled, shares some of the features of the valve described in his 1996 Patent. Why? A. The Stephens valve features may not speak to any of the patent Claims. B. The 1996 patent expired in 2016, so there is no infringement in any case. C. The purpose of a Patent is not only to protect the inventor's rights, but also to teach the general public in order to encourage technical innovation. I expect that the Stephens valve builds on the learned history of innovation from valves introduced historically ("protected" and unprotected) and taught in previously issued Patents. We all benefit from such innovation and continuing progress.

[Sesquitone]

To be even clearer, the enforceable part of a Patent is not the drawings or the description of the invention, it is the specific wording in the Patent Claims. A "competing" device may share many of the features of other previously patented inventions, but unless any of those features violate the specific Claims of a Patent, there is no infringement.

Benny Leonard does not seem to mind that the Stephens valve, though differently assembled, shares some of the features of the valve described in his 1996 Patent. Why? A. The Stephens valve features may not speak to any of the patent Claims. B. The 1996 patent expired in 2016, so there is no infringement in any case. C. The purpose of a Patent is not only to protect the inventor's rights, but also to teach the general public in order to encourage technical innovation. I expect that the Stephens valve builds on the learned history of innovation from valves introduced historically ("protected" and unprotected) and taught in previously issued Patents. We all benefit from such innovation and continuing progress.

Not only do I not "mind" the production of a valve based on the unsymmetrical geometry of my (vented) ULTRA valve patent from January 2000, I encourage other manufacturers to build on all the "prior art" in order to advance the state of the art.

But let me reiterate. The design in question is not that of the 1996 patent--in which the rotor was not vented. A valve based on that design would sound like someone was continually popping bubble-wrap!

To get a patent granted, the proposed design must not be "obvious" in relation to prior art (even if the prior-art patents have long expired, or even if earlier designs were never patented but "well known in the art"). But even what might seem to be minor "tweaks" to the prior art can be patentable if the improvements are not immediately "obvious", as seen below in patents granted over thirty years after the original Thayer-valve patent.



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