Hi, is anyone able to point me in the direction of pictures or patent number that describe the retracting & rotating main wheel of the SZD Cobra or the Grob Twin II A? Regards Mark

At 07:53 27 January 2020, wrote:
>Hi, is anyone able to point me in the direction of pictures or patent
>number that describe the retracting & rotating main wheel of the SZD
Cobra
>or the Grob Twin II A? Regards Mark
>
The Grob Twin IIA has a fixed gear. I assume that you mean the
Grob 103 Twin Astir (1) which does have the rotating retracting gear.
LTB Lindner in Germany acquired all Grob glider patents and rights,
and acts as the pseudo factory now. You can contact them at:



RO

Patents run for 20 years, so anything connected to Grob gliders will have expired long ago.

On Tuesday, January 28, 2020 at 12:10:26 AM UTC-5, Tango Whisky wrote:
> ...anything connected to Grob gliders will have expired long ago.

Except mostly for those G103s ;-)
Think they'll last as long as the 2-33s?

On Tuesday, January 28, 2020 at 12:10:26 AM UTC-5, Tango Whisky wrote:
> Patents run for 20 years, so anything connected to Grob gliders will have expired long ago.

...... unless they get renewed.

Uli
'AS'

Le mardi 28 janvier 2020 06:20:29 UTC+1, AS a écritÂ*:
> On Tuesday, January 28, 2020 at 12:10:26 AM UTC-5, Tango Whisky wrote:
> > Patents run for 20 years, so anything connected to Grob gliders will have expired long ago.
>
> ..... unless they get renewed.
>
> Uli
> 'AS'

You can't renew a patent after 20 years. It becomes public domain, and that's it.

On Tuesday, January 28, 2020 at 8:58:57 AM UTC-5, Tango Whisky wrote:
> Le mardi 28 janvier 2020 06:20:29 UTC+1, AS a écritÂ*:
> > On Tuesday, January 28, 2020 at 12:10:26 AM UTC-5, Tango Whisky wrote:
> > > Patents run for 20 years, so anything connected to Grob gliders will have expired long ago.
> >
> > ..... unless they get renewed.
> >
> > Uli
> > 'AS'
>
> You can't renew a patent after 20 years. It becomes public domain, and that's it.

TW - that is generally correct and after 20 years, there is rarely any interest in continuing any protection. But sometimes, there is and a good patent attorney will figure out how to revitalize that protection by adding new aspects to the process or invention. It becomes basically a new patent that tries to cover as much of the old stuff which wasn't disclosed before plus the new stuff. That's why good patent attorneys make the big bucks they typically do. ;-)

Uli
'AS'

On Monday, January 27, 2020 at 2:53:39 AM UTC-5, wrote:
> Hi, is anyone able to point me in the direction of pictures or patent number that describe the retracting & rotating main wheel of the SZD Cobra or the Grob Twin II A? Regards Mark

I use Google Patents for a lot of searches.

Try this link for the Grob patent; https://patents.google.com/patent/DE4216787A1/en?inventor=Burkhart+Dipl+Ing+Grob&page=2

Good luck!

That mechanism showed up for the Twin III, and is for the nosewheel steering. The OP is asking about that thing in the Twin Astir that makes the instructor's hips sore.

On Wednesday, January 29, 2020 at 7:34:11 PM UTC-8, Garrett McEwen wrote:
> That mechanism showed up for the Twin III, and is for the nosewheel steering. The OP is asking about that thing in the Twin Astir that makes the instructor's hips sore.

Grob devised a novel retraction system for the Twin Astir. The single wheel was designed to rotate 90° sideways before retracting "flat" under the rear seat, resulting in a rather unusual seating position. This was only incorporated in early examples, later on, the wheel was fixed.

Hi Haven, yip, that's exactly what i am talking about. Do you know if there are pictures of it anywhere?

On Monday, February 10, 2020 at 12:48:44 AM UTC-7, wrote:
> Hi Haven, yip, that's exactly what i am talking about. Do you know if there are pictures of it anywhere?

Contact Robert Mudd at Composite Aircraft Repair in Moriarty. He recently did a bunch of work on the Twin Astir landing gear, and he generally documents his work with photos. I don't think he has a website, but his contact info is in the back of Soaring Magazine under Sailplane Repairs.