Engineering Help with a Foldable Wheel Mechanism

[DChachulski]

We’re working on a project and need help designing a foldable wheel mechanism. The idea is to have the wheels at the bottom of the trolley clip securely into two positions:

Flat Position – The wheels are tucked under the trolley, allowing it to lie flat.

Extended Position – The wheels are rotated outward to allow the trolley to stand upright.

We want a mechanism that allows the wheels to clip into place in both positions. To release the wheels, we envision a button-based mechanism that disengages the lock, allowing the user to manually rotate the wheels to their desired position. However, the mechanism should not automatically lock the wheels back into place when rotating – the user should manually clip them into position after releasing the lock.

Our current design includes a flat metal bar that holds the main pipe where the peg and wheel are attached. However, we’re struggling to visualize how the release button and locking mechanism should work together to achieve this functionality.

If anyone has ideas, diagrams, or references to similar mechanisms, we’d greatly appreciate your input!

 

[LittleInch]

I don't think the button release mechanism adds anything to the functionality and adds a lot of complications.

even if you do find something to work, the bag will still need to be laid on its back or side whilst someone folds the wheel underneath so what good is the release cable? Makes no sense to me. The mechanism looks good so far, you just need to provide enough friction or a clip to hold the wheels in the down position, but how do they stay folded under?

only other option is to insert a spring somewhere which holds the wheels up and then your mechanism can be a simple ratchet that holds the wheels in position when you lift one side and use your foot to push it into position?

 

[rb1957]

"the user should manually clip them into position after releasing the lock." I think this messes up the idea. Initially the wheels had two positions ... retracted and extended ... simple. Maybe this is "just English" ? I agree that to have someone move the wheels into their extended position is "clumsy". A simple spring (or many other ways) would deploy the wheels after they are released, but you can do that mechanical work manually ... but remember two positions only ... fully deployed, and fully retracted. Like I said maybe just who I read your words !?

But then if you are going to manually move the wheels from one position to the other, why a "button" ? lay the bay down, so the wheels are off the floor; have the wheels (each one) secured in their retracted position by a pin into the structure of the bag, undo each pin (in turn), move the wheel to its extended position, and secure (each wheel) with the same pin into another part of the structure, or have a second location on the wheel (a second flange at 90 degrees ?), to secure (each wheel) in its extended position.

no?

 

[btrueblood]

Hmm. The wife and I do a lot of traveling with roller bags. The best ones have the rollers always available, i.e. you tip the bag forward and the wheels (embedded in the lower corner of the bag) are ready to roll. A folding wheel setup just slows you down to either lower or raise the "landing gear" and in my mind would be more prone to breakage unless you traded valuable luggage space for wheel wells.

 

[MintJulep]

It's too complex.

All you need is a spring to push the wheel/leg to one end of its travel, and a notch for each position.

 

[rb1957]

the "only" advantage I see is there may be less room required in the overhead bin, but I agree with btb that the current generation do a good job of hiding the wheels. To hide them any more (like fully retracted) would lose room inside the bag (ok, a little). Maybe better is fully removable wheels ??