Rapido 40, 50 Folding system

[patrik111]

Hello,

Very intrigued by the folding systems shown for the new M&M Rapido 40 & 50

How does that work?
Locking in place for sailing and for folded, joint low down in ama and... But how does is look?


Let the speculations begin!
Please bring pictures

 

[upchurchmr]

This is just Ferrier's patented system from 30 years ago.
Nothing wrong with it, but nothing new either, from the very minimal information provided.

The patent has expired, btw. So this is legal.

 

[patrik111]

Most of it does absolutely consist of Farrier geometry, but the amas are articulated vs the beams, meaning in folded position, they are still in an relatively upright position. How that is achieved is what is keeping me awake.

 

[John Perry]

I recall that some years back Ian Farrier in one of his writings on the internet said that he had considered a mechanism like this that includes extra pivots and links to keep the floats upright during folding and I think, but cannot be sure, that he said that he had taken out a patent for it. He then went on to say that he did not think the extra complication would be worth the benefit for most owners so he had not taken the idea further.

I would think that this arrangement would be more worthwhile on a larger boat than most of those designed by Ian. Ian's boats are mostly designed to be road trailerable, so the folding mechanism is mainly intended to facilitate that. Unlike the Dragonfly system, the Farrier system is not ideal for frequent folding for marina berths. For boats much over 10m road trailing becomes irrelevant and the greater width perhaps leads to a greater need to fold in marinas.
John

 

[bruceb]

It looks as if the tips of the beams go all the way to the bottom of the floats, below their center of flotation so most of the load is just vertical. Probably a simple pin on the float deck or a fitted insert in the slot would keep them in place. I drew something similar a few years ago for my Buc 33 but I did not think I was capable of building it. I hope M& M can make it work correctly, tri's need some fresh folding ideas and since Farrier's patents have mostly expired it is a wide open field again.
B

 

[Tony.Ellen]

The Patent as mentioned above

 

[bruceb]

That is interesting, the patent shows somewhat different geometry than the video. I have to wonder how defensible the patent would be. Watch where the beams intersect the deck.
M&M are very experienced designers but most multi folding systems are based on very generic mechanical principals, (Like front end loaders and many other machines) so defending them in a patent dispute might not go so well. Whom ever brings the best legal fire power would probably prevail. In the past, the market was not worth the investment but that might be changing. As a former boat dealer, I have long felt that Ferrier's patents stifled multihull development for 20 years, and I hope new ideas are not restricted to one company.
B

 

[waynemarlow]

There is actually another beam ( NO 45 in the patent sheet ) that goes from the central beam pin, outwards to the edge of the float.

 

[John Perry]

As I mentioned above, Ian Farrier wrote about a mechanism with extra pivots and links to keep the float vertical as the boat folds and seeing the Rapido patent above I think it is likely that this is what Ian was writing about, in which case the Rapido patent is potentially invalidated.

Ian Farrier's arangement as seen on most of his trimaran designs was a mechanism that mechanical engineers would describe as a four bar linkage and this proposal adds a second four bar linkage joined onto the original one. Four bar linkages are not in themselves a novel idea being used in a wide range of machinery.

One point is that it is important that the two cross beams on the same side of the boat both fold together - if one folds ahead of the other the pivots will come under undue load and will probably break. With Ian Farrier's trimarans the float being rigidly connected to both cross beams ensured that the two cross beams move together. It would appear that Rapido have added structures connecting the inner ends of the cross beams, these structures providing a nice solid walkway alongside the main hull when the boat is unfolded. Presumably these structures also serve to provide the necessary connection between cross beams to ensure that both cross beams move together as the boat is folded.