Caravan Stability 2

[JohnMW]

Hi every one,
This subject goes on forever and I have been monitoring it. Some of the respondents I recognise from other sites and we have had lots of exchanges on this subject most of which are based on the common beliefs of experienced caravan owners. As a qualified Transport Engineer of some 40 years I had designed a system I called the Differential Stability system over 20 years ago. I studied the problem using Calculus -derivatives and integrals and worked out actually what caused the uncontrolled lateral sway. I then produced a prototype to prove the concept and for the last 6 years I have toured France with it and subjected it to moderate poor loading, high speeds (80mph in France) during that time I have never experienced a (snake) have survived a 40 degree jackknife under full control and endured high side winds in heavy traffic. I have not patented it but have offered it to the majors who have not responded to my correspondence. No one has seen the device because I keep it under wraps so I can only describe what it does. The secret to the success is that it uses no electronics and can apply an equal and opposite force at the centre of equilibrium and is proactive in that it stops a snake before it starts - it does not interfere with. the normal overrun brakes and will never shut off on rough roads, costs about £200 and will retrofit any caravan or trailer. I will donate my van and the device free to any reputable company who can take it to market - with some conditions.

 

[Dustydog]

Hi every one,
This subject goes on forever and I have been monitoring it. Some of the respondents I recognise from other sites and we have had lots of exchanges on this subject most of which are based on the common beliefs of experienced caravan owners. As a qualified Transport Engineer of some 40 years I had designed a system I called the Differential Stability system over 20 years ago. I studied the problem using Calculus -derivatives and integrals and worked out actually what caused the uncontrolled lateral sway. I then produced a prototype to prove the concept and for the last 6 years I have toured France with it and subjected it to moderate poor loading, high speeds (80mph in France) during that time I have never experienced a (snake) have survived a 40 degree jackknife under full control and endured high side winds in heavy traffic. I have not patented it but have offered it to the majors who have not responded to my correspondence. No one has seen the device because I keep it under wraps so I can only describe what it does. The secret to the success is that it uses no electronics and can apply an equal and opposite force at the centre of equilibrium and is proactive in that it stops a snake before it starts - it does not interfere with. the normal overrun brakes and will never shut off on rough roads, costs about £200 and will retrofit any caravan or trailer. I will donate my van and the device free to any reputable company who can take it to market - with some conditions.

Hi John,
Assuming you are not a Troll have you considered talking to The Dragons Den for financial support to bring your invention to the market?

 

[JohnMW]

Hi DustyDog,
I assure you I am not a troll. As an engineer and operator (Retired) I have more time to devote to problems that seem to go on and on with no apparent solution. I am also one of the most inspirational person you could meet on the subject of technology so much so my son has a masters degree in electronics etc. So it may seem odd that I should perfect a purely mechanical solution to a caravan anti-snake device. I can justify this very simply. Uncontrolled snake is a complex subject that few have fully understood. The best solutions without a control system are fully covered in all the previous posts and most are valid. However, from much research I found that almost every caravan owner has had some experience of this phenomenon and they know how to feel for it before it gets out of control. So would it not be great if one could just hitch up and go with the knowledge that it is like driving your car without the stress. This system can be connected in under 10 seconds and it can sense every reaction of the tow car - Pitch, speed, poor roads and poor loading. it requires no electrical connection and only adds 10.kg to the van and it will never shut down when a problem occurs since there is nothing to go wrong. It does this without any special tow car, however, it works with much higher integrity and control if the tow car has ESP since the van operates on each individual wheel just the same as that magic ESP on the car and the two work together like bread and butter. So why would the likes of BPW and Alko not take an interest? If it does not do all I say they could just walk away. Now I don't need the money so unless someone shows an interest or finds out how my system works then it will die with me.

 

[otherclive]

JohnMw
It sounds interesting but do you have any videos that show it’s capabilty under demo conditions. But not showing your proprietary intellectual property.

 

[Dustydog]

John
Die or not you will be wise to take out a patent on your invention.
May I suggest you try and talk to engineering gurus, entrepreneurs, like Sir James Dyson. I fully understand you can't say much on here. But if you can do what Clive suggests it may help.

 

[ProfJohnL]

Obviously I have not seen the product, and it is not fair to prejudge anything without being able to make a fair assessment of it, But I cannot ignore the inventors published claims which are exceptional to the point of being unbelievable! I am firm believer in the adage of "The best designs are the simplest" but it is not the same to say "the simplest designs are the best"

...a purely mechanical solution to a caravan anti-snake device...
This system can be connected in under 10 seconds and it can sense every reaction of the tow car - Pitch, speed, poor roads and poor loading. it requires no electrical connection and only adds 10.kg to the van and it will never shut down when a problem occurs since there is nothing to go wrong. It does this without any special tow car, however, it works with much higher integrity and control if the tow car has ESP since the van operates on each individual wheel just the same as that magic ESP on the car and the two work together like bread and butter...

I have yet to see a 100% reliable mechanical system.

As as John states

...Uncontrolled snake is a complex subject that few have fully understood...

History has shown it is very very VERY rare that such a complex set of issue can have a non invasive, simple to fit, system to overcome such a complex set of input factors and that can produce an effective control solution.

Just from a simple mechanical perspective of the information already given, the implication is that somehow the added system will independently of the normal brakes, apply the brakes on the trailer's wheels in response to the outfits behaviour. That must require a second braking system of some description, and as we know brakes do wear out, and as they get older they can malfunction. Also they will require some form of energy to cause the brakes to apply, Where does it get that energy?

....So why would the likes of BPW and Alko not take an interest? If it does not do all I say they could just walk away. Now I don't need the money so unless someone shows an interest or finds out how my system works then it will die with me.

Your thousands of miles without incidence frankly proves nothing, its the details of the number of incidents that arose where the system acted, that would be a more useful presentation.

I find it incredibly hard to believe the likes of Al-Ko or BPW would pass by the opportunity to acquire a technology that made towing trailers much easier. If the system was as good or even half as effective as JohnMW claims, these companies or others would be fighting over it, either to exploit it or to bury it to protect their own technological investments in similar systems.

Perhaps the likes of Al-Ko and BPW have seen the scheme and spotted some flaws that the inventor has not? and as the John suggests they have "walked away" I am left wondering if this is similar the the "Tyre Band" products where it's efficacy is more in the mind than in real life.

If the chassis manufactures aren't interested, have you tried caravan mover manufacturers? They have the knowledge to make sure a product will not compromise the chassis designs, They have proven routes to market in a similar field, and most would welcome another key product that makes caravanning more accessible.

It really isn't fair to start making claims about having found the holy grail of towing aids and then complaining in a public forum about how manufacturers of related products are not interested, then threatening to take the secret to the grave when no money is not the sticking point.

JohnMW please open my mind and prove me wrong.

 

[camel]

Hi John, what you describe sounds like something called 'The Hope Anti Jackknife' and was mainly fitted to fuel tankers, it was a mechanical device and was around in the 60's and 70's and did exactly what it said on the tin stopped lorries jackknifing, long before any kind of ATC or ABS came on the scene, am I getting warm,

 

[DrZhivago]

No one has seen the device because I keep it under wraps so I can only describe what it does. .... I will donate my van and the device free to any reputable company who can take it to market - with some conditions.

I once worked for London Transport and one of my occasional and lighter tasks was to look at technical ideas and "inventions" submitted from members of the public, hopefully for LT to adopt. I put "inventions" in quotes because most of these ideas had never got beyond the back-of-an-envelope stage, perhaps understandable as not many members of the public (except Elon Musk) are in a position to trial a revolutionary type of train for example; I tried to keep an open mind and give a fair report to our Chief Mechanical Engineer, but TBH none I saw were very practical. JohnMW's idea sounds like it has got beyond that, but companies like Alco will need far more than a piece of correspondence to take up an interest.

It is difficult, I know from seeing it at first hand. You will need to obtain the support of an industry insider, and be ready and open with demonstrations, videos, salesmanship etc. You will get nowhere by keeping it "under wraps". It is almost like political campagning, requiring money and charisma as well as the technical know-how. Patenting is a minefield BTW.

Look what Charles Parsons did at the Spithead Naval Review, in order to get his steam turbine noticed by the Admiralty ! :-

https://en.wikipedia.org/wiki/Turbinia

 

[Dustydog]

Camel, possible but no longer made and as you say all the electronic stuff has taken over.
The Hope system I think only operated under braking conditions not towing as such.

 

[camel]

Dusty, correct, no longer made but a good bit of kit at the time, but that was the idea of the Hope to work under braking condictions because that is when a jackknifed happened (normally) and actually the mechanics of the Hope had nothing to do with the brakes locking up once it felt movement between unit and trailer at speed there was a censor that activated locking pads on the fifth wheel mounting( that's the bit that connects the unit with the trailer), why do posts on here seem to get taken out of subject, Brian has a good idea but he wants to keep it himself for the moment, but why his post is taken apart by certain people who say that it can't be any good because non of the manufacturers don't want to know about it ,rubbish more than likely they want it for nowt,
Moderator Note:
I've edited this post to remove antagonistic comments.
Parksy

 

[Dustydog]

Camel,
John MW may well have something good but all the cloke and dagger doesn’t help anyone get an understanding of what it is or can do.
Sir James Dyson is a good example of where mega companies like Hoover dismissed his revolutionary designs for vacuum cleaners. How they now weep hmy:

 

[JohnMW]

Hi to all who have responded,
First let me thank you all for your interest. the likes of Dragons den would not be interested in what I have simply because they are looking for tried and tested "Businesses" that are simply seeking finance. I have experience of Patents and frankly I think it only stands a chance if one has very deeeep pockets to wage a defence against infringement and by that time the world knows what it is and how to get around it. To those who would question that it is not possible to produce this device then i suggest you just sit back and wait. The energy that is capable of delivering this solution lies in the kinetic energy of the whole combination as it travels along - a good analogy of what this means is the way brakes work to stop a vehicle by dissipating the energy in the form of heat through the brakes. To discover what is going on when an uncontrolled snake occurs you really need to turn to maths by way of Calculus derivatives and integrals before you can understand how to fix it. To fix it one needs to apply a force "equal and opposite at the centre of equilibrium" ie when the trailer is very near to the inline position and no more. At this present time there is no prior Art of patents pending that can do this except my "Differential Stability" that's what I called it when I designed it. It is so clever it prevents uncontrolled sway from starting but does not prevent the absorption of side forces etc pushing the trailer otherwise that would introduce other lateral problems to the whole combination, however, it certainly does control the effect of the side force to manageable levels so that the potential energy is easily managed on the return. I need to add here that this is where the electronic offerings fail to consider since they first need to sense a sway a number of times then apply a brake force to both trailer wheels. They do this at a point where maximum potential energy is greatest thus adding to the swing return velocity so they pray that it will slow the combination enough to get it below the swing frequency. NB during a severe swing some of the potential energy actually engages the overrun brakes anyhow this is one of the reasons why uncontrolled sway is more dangerous on downhill runs.
Phew - there is much more to this than I can fully cover here.
I have had video cameras all over the van during the six years of use and I have tweaked it to perfection - I cannot let you see any because it would release it to the world and no serious company would take it on and do the work to get it to market. I alway remove it when on site - it takes me about 5 minutes to do this so it keeps the nosy parkers off. I did say there is nothing to go wrong but of course there is if the van is not maintained or the device gets broken but anyone can fix these things because it is so simple. I meant electronic complexities plugs etc.
The Hope system is nothing like this and you are referring to a truck accessory - I had 40 years working on those - Registered Transport Engineer. If you know anything about flying gliders etc you will know that the wings have a design called washout, this give a warning to the pilot that a stall of the wings is imminent by a very slight vibration - no technology here. My system has a feature that works in a similar way - if the van is loaded very badly with say a negative nose weight my system issues a slight but rapid vibration but will not let it develop into an uncontrolled sway and does not pose any threat until that is rectified.

Regards
John Wilson
BTW Telling you this is hoping to get the big boys attention not selling it to you. Try looking at Dexter in America - they bought out ALKO and they pinched my concept and tried to do it with electronics but for the Electric brakes they have in US - I wrote to them and they responded by pointing me to guess who ALKO who have still not responded. I think this is because they are going to try and do it with electronics for overrun -
they European Market - they will not succeed on price and simplicity.

 

[otherclive]

Dusty, correct, no longer made but a good bit of kit at the time, but that was the idea of the Hope to work under braking condictions because that is when a jackknifed happened (normally) and actually the mechanics of the Hope had nothing to do with the brakes locking up once it felt movement between unit and trailer at speed there was a censor that activated locking pads on the fifth wheel mounting( that's the bit that connects the unit with the trailer), why do posts on here seem to get taken out of subject, Brian has a good idea but he wants to keep it himself for the moment, but why his post is taken apart by certain people who say that it can't be any good because non of the manufacturers don't want to know about it ,rubbish more than likely they want it for nowt, ,

Since you deign to raise the topic the thread about eyesight and night driving raised a legitimate topic/concern. It’s a fact that irrespective of your eyesight your night vision does deteriorate as one gets older. Therefore to raise the issue of the problems with high intensity lights from oncoming vehicles is legitimate as is the discussion on possibly fitting higher intensity bulbs ( but legal ones) to help the OP with night driving. There are times when an optician cannot help despite having an annual eye test. It’s called ageing.

 

[Parksy]

Dusty, correct, no longer made but a good bit of kit at the time, but that was the idea of the Hope to work under braking condictions because that is when a jackknifed happened (normally) and actually the mechanics of the Hope had nothing to do with the brakes locking up once it felt movement between unit and trailer at speed there was a censor that activated locking pads on the fifth wheel mounting( that's the bit that connects the unit with the trailer), why do posts on here seem to get taken out of subject, Brian has a good idea but he wants to keep it himself for the moment, but why his post is taken apart by certain people who say that it can't be any good because non of the manufacturers don't want to know about it ,rubbish more than likely they want it for nowt,
Moderator Note:
I've edited this post to remove antagonistic comments.
Parksy

If John Wilson didn't want people to discuss his device he wouldn't have written about it on a public internet forum Camel.
As far as the device itself is concerned, it might be helpful if JohnMW contacted Practical Caravan towcar editor David Motton via the Contact Page to see if he can offer any advice on marketing etc.
Posting vague details onto Practical Caravan forum message boards in the hope of generating commercial interest or awareness is futile, because Rule 6 of forum etiquette prohibits comments containing advertising or promotional material

 

[Mel]

I know nothing about either engineering or business; well not enough to help. However I am aware that Social Media can be an effective platform for launching oneself (look at Justin Bieber :blink: ) or ones product. However, I am doubtful that PC forum is the best social media for this purpose; but perhaps the OP is also all over Facebook and You Tube.
Hope you do have something; I am all for British ingenuity.
Mel

 

[ProfJohnL]

Hello John,

Thank you for more insight into your concept. Importantly the added detail ( which far from complete) does show that your original post did include exaggerated claims like "nothing to go wrong" I therefore do not appologise for my previous comment. However I do agree that trying to get a patent on your system would be very expensive, and I suspect impractical, because the concept of differential braking in response to an unwanted movement has already been established and turned into a saleable product by both Al-Ko and BPW.

So the most significant difference of your system, is you claim its more sensitive, and derives it's actuator power from the momentum of the trailer working against the tow vehicle, and again this is not new as that is primary energy source used by the over run braking system.

I strongly suspect that if you do have a workable product, your most likely partners wold lie in the accessory market for the reasons outlined previously. I have just had another thought. It might be worth contacting
Dr Jos Darling who is a Senior Lecturer in Mechanical Engineering and Director at the University of Bath.
He has been heavily involved with the interaction of tow vehicle and trailers.

I would love to know more about your system, but sadly I am not personally in a position to offer any substantive help.

 

[JohnMW]

Obviously I have not seen the product, and it is not fair to prejudge anything without being able to make a fair assessment of it, But I cannot ignore the inventors published claims which are exceptional to the point of being unbelievable! I am firm believer in the adage of "The best designs are the simplest" but it is not the same to say "the simplest designs are the best"

...a purely mechanical solution to a caravan anti-snake device...
This system can be connected in under 10 seconds and it can sense every reaction of the tow car - Pitch, speed, poor roads and poor loading. it requires no electrical connection and only adds 10.kg to the van and it will never shut down when a problem occurs since there is nothing to go wrong. It does this without any special tow car, however, it works with much higher integrity and control if the tow car has ESP since the van operates on each individual wheel just the same as that magic ESP on the car and the two work together like bread and butter...

I have yet to see a 100% reliable mechanical system.

As as John states

...Uncontrolled snake is a complex subject that few have fully understood...

History has shown it is very very VERY rare that such a complex set of issue can have a non invasive, simple to fit, system to overcome such a complex set of input factors and that can produce an effective control solution.

Just from a simple mechanical perspective of the information already given, the implication is that somehow the added system will independently of the normal brakes, apply the brakes on the trailer's wheels in response to the outfits behaviour. That must require a second braking system of some description, and as we know brakes do wear out, and as they get older they can malfunction. Also they will require some form of energy to cause the brakes to apply, Where does it get that energy?

....So why would the likes of BPW and Alko not take an interest? If it does not do all I say they could just walk away. Now I don't need the money so unless someone shows an interest or finds out how my system works then it will die with me.

Your thousands of miles without incidence frankly proves nothing, its the details of the number of incidents that arose where the system acted, that would be a more useful presentation.

I find it incredibly hard to believe the likes of Al-Ko or BPW would pass by the opportunity to acquire a technology that made towing trailers much easier. If the system was as good or even half as effective as JohnMW claims, these companies or others would be fighting over it, either to exploit it or to bury it to protect their own technological investments in similar systems.

Perhaps the likes of Al-Ko and BPW have seen the scheme and spotted some flaws that the inventor has not? and as the John suggests they have "walked away" I am left wondering if this is similar the the "Tyre Band" products where it's efficacy is more in the mind than in real life.

If the chassis manufactures aren't interested, have you tried caravan mover manufacturers? They have the knowledge to make sure a product will not compromise the chassis designs, They have proven routes to market in a similar field, and most would welcome another key product that makes caravanning more accessible.

It really isn't fair to start making claims about having found the holy grail of towing aids and then complaining in a public forum about how manufacturers of related products are not interested, then threatening to take the secret to the grave when no money is not the sticking point.

JohnMW please open my mind and prove me wrong.

Hi I'm sorry if I implied a threat of taking it to the grave, The two aforementioned have never seen the device or acknowledged my correspondence so it is hard to see how they could decide. So far their systems cannot do what what I claim simply because they just can't. Consider this - to make their system work they need to build into the system electronic algorithms based of the voltage computation based on different van weights. Now if there is any resistance in the circuitry from the plug then it will deliver an erroneous voltage and either shut down or simply not work . I use a mechanical Algorithm in the same way the 4 stroke cycle of a combustion engine works - IF, AND,THEN,OR, as they say simples. Therefore Whilst I can tell you what it does I cannot tell you how it does it only the chosen one will get that information so for now just compare my claims with the others and sit tight - I will answer any question on what it can do openly and honestly. Unfortunately your suggestion has already been tried on some and I get the usual curiosity letter but no serious request to take it further.
Thanks for your intelligent questions.
Regards
John

 

[JohnMW]

Hello JohnL
Thanks for the post - I know of the Bath University project and have been a critic of what they have come up with after 25 years of investment - nothing. The model they produced only demonstrates what happens when there is a negative load on the nose and what we all have witnessed that make it positive and it helps a lot. If they had a hand in the Alko project then I think they should go back to the maths and the models and I have said so on their YouTube site. I do believe it was a migrant students who worked on that Not Dr Josh. However, I would be confident in sitting down with who ever and explain one or two things when the time is right. Just to be clear if my system were tested to destruction I dare admit there will be limits - even the very best things made have limits - go to Calculus and you can see where they are. Caravans can blow over if the wind is strong enough - they can skid on ice if you go too fast in those situations - i guess you and others will see where I'm coming from. I do not see any differential offerings from BPW or ALKO they only work of simultaneous braking of both trailer wheels - only Dexter have used this concept in America on ELECTRIC BRAKING SYSTEMS. I applaud Dexter for recognising the differential concept (Used on aircraft and agricultural braking systems) they have limited capability compared to mine - they shut off when the going gets rough, they do not sense jack knife
situations, they cannot present an equal and opposite force at the centre of equilibrium, they rely on electronics heavily and they cost a lot of money, they don't have one working on overrun brakes yet.
Many thanks
John

 

[ProfJohnL]

...why do posts on here seem to get taken out of subject, Brian has a good idea but he wants to keep it himself for the moment, but why his post is taken apart by certain people who say that it can't be any good because non of the manufacturers don't want to know about it ,rubbish more than likely they want it for nowt,

Hello Camel,

Whilst I did not see your whole comment before Parksy intervened, I sense you are pointing a finger at me. Yes; I will dissect comments where I feel there is need to do so, and, No; it's not taking it off subject.
Where controversial information without concrete evidence is put into the public arena, it needs to be tested.

Bearing in mind that caravans have been towed for well over 70 years, and other sorts of trailer for substantially longer, the issues of outfit stability have been experienced and considered for a long time. There is nothing like a crisis to bring human ingenuity to the fore, so it's highly likely that solutions to this problem would have come to light sooner rather than later. It's understandable that the advent of electronics spurred some new thinking and that resulted in both Al-Ko and BPW bringing systems to the market. So it is all the more surprising to be faced with and all mechanical system this late in the history of caravanning.

If you have followed this forum for any length of time you will know that I detest reliance on traditions, becasue that is simply an excuse not to look at a problem and to reassess the solutions suitability with reference to new technology and relevant information. If after reevaluation the traditional is still the best way, then that's fine, but in many cases new in formation proves the Traditions are not always the best way.

Consequently I don't discount out of hand JMW's idea, but it does need to be tested, and in this instance all we have is JMW's own words with no independent review.

In my view it is therefore necessary to drill down into the information supplied and apply a Strengths, Weaknesses Opportunities and Threats (S.W.O.T.) analysis to separate out the believable from the unbelievable etc. This give the OP the OP the opportunity to respond to certain points.

We do not know what information JWM supplied to the various manufactures he approached,. We don't know what the manufactures thought about the idea, There could be a myrriad or reasons why they have not supported it, but the absence of ANY support does call into question the possibility there are significant issues spotted by the companies technical teams.

All in all at this stage there are more questions than answers, and that means confidence in the idea being a workable product is low. Perhaps John needs a mentor to help him present his ideas more effectively.

 

[JohnMW]

Hi Mel,
You may be right in your comment but I thought start with people who use the product - trying to introduce a concept that is unknown or hard to figure out even by fellow engineers is fraught with misunderstanding or just plain doggedness and indifference. I do have a facebook account but I'm not a fan of any. I'm old fashioned and prefer a platform such as a lecture room with a board to get immediate responses. Face to face in sales was my forte - my successes were to follow a rule - never try to sell something to anyone if you know it's not right for them. That way I never sold anything - they bought from me.
Good luck is when preparation meets opportunity.

 

[JohnMW]

OOps
I just read the comment on Rule 6 and I will cease commenting - since I am not selling just promoting a concept I did not realise I was out of order so If you wish I will not be offended if the posts are removed and please accept my apologies Just like to say I am not a traditionalist but if you use an overrun brake system on your van because it is inexpensive , reliable and efficient then to a huge extent you have to be labeled a traditionalist and not without good reason. I might also add that if it is that good then a simple addition to that system that in fact works on the same principles should be encouraged - I did not mention that my system integrates a very powerful hydraulic damper that renders the friction hitch redundant though I would still recommend that hitch for ball security not stability - laws of friction etc. If ever you believe in belt and braces this is a good example. It also presents a powerful anti pitch control several times more powerful than the
friction hitch. If you want me to still post then let me know.

 

[Parksy]

OOps
I just read the comment on Rule 6 and I will cease commenting - since I am not selling just promoting a concept I did not realise I was out of order so If you wish I will not be offended if the posts are removed and please accept my apologies Just like to say I am not a traditionalist but if you use an overrun brake system on your van because it is inexpensive , reliable and efficient then to a huge extent you have to be labeled a traditionalist and not without good reason. I might also add that if it is that good then a simple addition to that system that in fact works on the same principles should be encouraged - I did not mention that my system integrates a very powerful hydraulic damper that renders the friction hitch redundant though I would still recommend that hitch for ball security not stability - laws of friction etc. If ever you believe in belt and braces this is a good example. It also presents a powerful anti pitch control several times more powerful than the
friction hitch. If you want me to still post then let me know.

Because the details of your product were originally posted to a thread which was over eight years old and they have remained somewhat vague, perhaps for commercial reasons, I have watched this thread and allowed it to continue because the subject matter creates an interesting discussion at a time of year when forum activity is often reduced.

Although I suspect that you may initially have been hoping to attract some form of investment, the reality in these times of austerity is that financial assistance from PCv forum members is highly unlikely to be forthcoming, and if such investment had been asked for directly the request would have been removed as soon as it appeared.
Forum users who are willing to invest their time in forum discussion with you, or to challenge your assertions are perfectly at liberty to do so if they wish however, indeed some of us might learn something about cause and effect of caravan instability.

Perhaps the magazine editorial staff might take an interest in your product or write an article about your efforts to invent a caravan safety related product that had never been thought of before?
I separated your recent comments from the eight year old original thread so that you could send a url link to this newly created thread.

Please continue your discussion within the parameters set out in forum etiquette if you want to.

 

[otherclive]

John MW
I think the term “ migrant students” at University of Bath is incorrect. I suspect that you were referring to overseas students. And what particularly is your point? I did extensive work with Professor Ted Bowns at the Uof B Fluid Power Center where quite a number of the undergraduates and postgraduate students were from overseas and as far as I could determine I couldn’t say there was any difference in academic ability or diligence compared to U.K. students.

 

[ProfJohnL]

Hello John,

I will warn readers now this is a long post, it has taken along time to compose it, and it will be by its nature quite detailed. So if you don't want to be bored stiff don't read it and don't complain about it. By all means challenge salient facts or assumptions I have made.

Hello JohnL
Thanks for the post - I know of the Bath University project and have been a critic of what they have come up with after 25 years of investment - nothing. The model they produced only demonstrates what happens when there is a negative load on the nose and what we all have witnessed that make it positive and it helps a lot. If they had a hand in the Alko project then I think they should go back to the maths and the models and I have said so on their YouTube site. I do believe it was a migrant students who worked on that Not Dr Josh. However, I would be confident in sitting down with who ever and explain one or two things when the time is right. Just to be clear if my system were tested to destruction I dare admit there will be limits - even the very best things made have limits - go to Calculus and you can see where they are. Caravans can blow over if the wind is strong enough - they can skid on ice if you go too fast in those situations - i guess you and others will see where I'm coming from. I do not see any differential offerings from BPW or ALKO they only work of simultaneous braking of both trailer wheels - only Dexter have used this concept in America on ELECTRIC BRAKING SYSTEMS. I applaud Dexter for recognising the differential concept (Used on aircraft and agricultural braking systems) they have limited capability compared to mine - they shut off when the going gets rough, they do not sense jack knife
situations, they cannot present an equal and opposite force at the centre of equilibrium, they rely on electronics heavily and they cost a lot of money, they don't have one working on overrun brakes yet.
Many thanks
John

I think you underestimate the involvement of the staff at the University of Bath, and whilst the often demonstrated Bailey model is a simplified model of the issues involved, it has demonstrated the importance of loading strategies in a way easily digested by most caravanners. The origin of the student involved with the study is totally irrelevant.

The University of Bath have been involved with extended projects usually in conjunction with a commercial sponsors, and they have a good reputation in the field vehicle dynamics and engineering in its wider forms. This is one way they bolster their funding by offering research facilities to the commercial sector. Such programmes are always overseen by senior university staff to ensure that not only do the programmes meet the clients criteria, but they also provide opportunities for students to have real world experience.

It is common for a student to use these programmes, or at least part of them, for the basis of a final project and dissertations. Their final papers may not contain the greater project outcomes which may be protected for reasons of commercial confidence. If a student paper seems to have a very narrow field of application, there may be other control criteria that prevents the student for expanding the subject.

Don't forget that good research projects do not always end up supporting the initial hypothesis. During the course of a project the results and analysis may start to show why the initial hypothesis is untenable. They may end up supporting the the null hypothesis, which may be as valuable, to prevent wasted investment on chasing a less effective ideas.

U of Bath have served Bailey Caravans, Williams F1, and other significant manufacturers in the automotive and caravanning sectors. I seriously don't think these companies would continue to use UofB if their project management were seen to be less than perfectly satisfactory.

Forums are not the best way to get into meaningful discussions with organisations, you need to make a more formal direct approach.

I can full understand that you will have used mathematics to help you with your concept. Calculus is one of several mathematical tools and may be necessary to produce the model to describes your system and provide predictive information on behaviours. But I would be very surprised if the chassis manufactures do not also use mathematical modelling, probably linked to CAD/CAM systems, so your approach to problem solving is not fundamentally different.

However most laymen will be perfectly able to conceive that road and weather conditions can and do affect towing behaviours, all they are primarily interested in is having a safe method of managing these characteristics. A knowledge of higher mathematics is not required, only the funds to purchase the equipment.

I can comprehend that differential braking might offer some advantages over shared braking and how that may be a benefit to aircraft especially on landing, but the agricultural comparison is not really fair as its purpose is somewhat different and usually performed at much slower speeds.

I have to assume you are referring to the caravan braking systems when you claim that some of them shut off when the "going gets rough". I have seen no other reference to your assertion, and the companies information about them certainly makes no mention of it.

It was my belief that the ATC system supplied by Al-Ko used differential braking. However I made further enquiries and I stand corrected. I cannot find enough information about the BPW system to be certain but I suspect it does as you say, work on both wheels simultaneously. But contrary to your later assertion, it is very clear that both Al-Ko and BPW do have systems that operate on Over run braking systems.

Reliance on electronics is not automatically a bad thing, It is true that electronics can fail, but so can all mechanical products. Good design of electronics can bring MTBF rates to exceeding low levels and often somewhat better than mechanical processes. Talk to your son about the electronics he uses.

You obviously genuinely believe you have a wonderful product idea, and if it's really as good as you say then I think all caravanners would want one. But it does concern me how you have presented your situation by making exaggerated unsubstantiated claims for your system, for example "nothing to go wrong" and "more reliable than electronics" also how you have sought to undermine the competition, again by making unverified claims of their systems failing when "the going gets tough" etc.

This is not advertisers license but false advertising bordering on libellous. This is not the way to impress possible investors. Stick to provable facts, and give citeable evidence.

Best of luck. PJL

 

[JohnMW]

Hi JohnL
I did read all your post and thanks - I am reluctant to go on to much on sites such as this and often being too brief can and does make for a return avalanche of words. I completely agree with what you say and also with respect to the Universities - my son did his masters degree in electronics and we share a great deal between us. He would describe me as a rebel and non conformist, I always question the status quo. I love mathematics, however, experience has demonstrated that it has limits and multiply the results by at least two in the real world - having plenty of redundancy is a good thing. I have built sailing yachts and two large houses with my own hands and done the structural calcs in the design and checked by a structural engineer for the benefit of the inspectors. Lifting equipment has SWLs of 5 times the min.
I do keep an eye on the industry especially my pet subject of automotive stability. If you check out the Dexter site you will note that they do cut out the system if it hits a rough spot on roads, however, to be fair, it does re-engage when it smooths out. Dexter and ALko were fighting for supremacy in the states over this stability issue - and the market moved quite rightly towards the differential concept simply because the trailers were heavily into Electrically operated brakes on trailers - Dexter won and bought out AlKo. Now about the time I designed my system (80s) no one had even thought of stability systems it was only that I had a pilots licence and an interest in aircraft that I realised then that this problem of snaking might be solved with a differential concept. As usual when one starts talking about these ideas others take notice.
But it has been a long time coming and back then I honestly thought someone would discover it and put it to use - alas still no progress. First someone had the idea that friction stabiliser on the nose would do the trick - well it did a little but my knowledge of friction suggested otherwise- the motor industry had moved on from friction dampers to hydraulic years ago - proven in the college labs. So along come Alko with a potty idea that a 50mm ball could dampen a 7 meter lever with two little friction pads - it causes more annoyance with the rubbing noise and creates wear on the overrun shaft and just prove they know best they change the bronze bushes to nylon. The overrun shaft tends to jamb if worn to much and does inflict an added pulse to the potential energy of a snake.as it releases thus increasing the return velocity kinetic energy. Next they come up with the ATC well what can I say anymore. You say they now use mathematical models to quickly get the numbers. Well most have forgotten the rules of calculus derivatives ( if they ever understood them) and rely on these programmes - wow. This is like the pilots I knew who went on to become airline pilots who have forgotten how to fly without computers so when real problems occur the rest is history.
I digress - from examination of the chassis loadings when a sway is induced the outer wheel greatly affects the slip angles of the tyre in that it digs in to resist the cornering, now since the swing is not Simple Harmonic Motion the energy generated accelerates the nose towards the tow vehicle (Radial low profile ply tyres are no friend of caravans in this situation), some of this energy is absorbed by the overrun shaft and it abruptly applies the brakes enough to catapult the van back to the CoE and then you have the start of an uncontrolled sway. On the rebound if it continues across the other side this is amplified again, however, this may be too much for the brakes to absorb so the back end of the tow car is pushed across thus destabilizing the whole outfit.
Enough for now

John