Trollies on travelators

[Panic Button]

Several supermarkets have travelators that take shopping trollies between floors. The trolley wheels lock when you are on them.

How does this work? Is it a mechanical thing with the wheel flanges locking into the grooves, or is there some magnetic force at work?

[Loosehead]

The flanges on the wheel rotate, the Hub in between them doesn't, when both flanges settle into the slots on the travelator the hub acts as a break.

[samsong7]

The ones in ASDA are magnetic

[hayley2956]

really, they r magnetic?? that must be a hell of a magnetic force to keep a heavy trolley in place coz u cant move them at all!!!

[Panic Button]

That makes sense Loose, I had been looking at the flanges but couldn't work out how the trolley stopped so firmly.

I had thought it might be related to the system where trolleys stop if you take them off the supermarkets property. How does that work?

[Loosehead]

obviously a new kind of magnetism as the trolly wheels are plastic, mmmm......

[Loosehead]

The ones that lock when you take them off site have a plastic sleeve that slips under one wheel, it has a metal plate so it doesn't wear through quickly as the bemused shopper tries to drag the trolley along. It is activated via an induction circuit that is activated when a sensor is passed. Same sort of thing as the card entry systems where you wave the card near a sensor and the door opens. Have a look next time you see a locked trolley, usually the sleeve is yellow.

[chazza]

Ours are magnetic as well, only one set of wheels locks, the others do not. If you really pull them up you can separate them but you can feel the pull working the same way as a magnet (ie at first when you lift it, the magnet's pull is very strong and then it gets weaker as you lift the trolley further off it)

[SteveD]

Here is your answer:

http://www.freepatentsonline.com/20040231098.h tml

I bet you now wish you'd never asked!!

[samsong7]

Loosehead, why the sarcasm about the magnetism .
Do you think you are the only person who can be right?
The ones in ASDA use magnets.
Yes, the wheels are plastic. but there is a magnet at the side of the wheels that hold the trolley to the metal travelator

[Loosehead]

because people like you have a primary motivation to try and make someone else wrong rather than to answer the question. You are motivated against all logic by a Na Na Nana na type thinking.

[samsong7]

Loosehead you are a blockhead. Read my answer. They are MAGNETIC wheels in ASDA. Question answered correctly. You obviously cannot stand it when some ones answer is different to yours can you. Na na na na na indeed. How childish !!

[Panic Button]

I'm not convinced Samsong.
The Asda I use has the flanged wheels that Loosehead describes.

I doubt if a magnet would have sufficient strength to safely hold a fully laden trolley, or if it had you wouldn't be able to get off the travelator at the end. Unless of course there is some sort of electro magnet in the travelator, but that might cause havoc with pacemakers.

[Hawkwalk]

The travelators are not magnetic.
They are as loosehead describes.

[samsong7]

I still disagree. Three people on here agree they are magnetic. Maybe different stores use different types of mechanisms.
I despise the people who post sarcastic comments just because someone has the audacity to disagree with them. How childish.

[Loosehead]

just think about it you plonker! They would have to elecrtomagnets to be strong enough, that's 4 per trolley and the travelator would have to switch them on or off. ASDAor anyone else are not going to spend that much when the solution is simple as I described above. Tell you what find me some evidence and I'll prostrate myself at your intellect.

[Panic Button]

Thank you all for your help in answering my question. I appreciate the input of all of you. I suggest we leave it there.

Subject closed.