Lift Mechanism (Step-on)

Can you use counter weights?

How about using two pairs of Chain and Sprocket to achieve the type of motion mentioned.

The Step platform would be attatched to some links of the chain permanently which would move the chain by certain distance per step taken.

The chain would run vertically along the height of the wall and at the both top and bottom it would run over a turning sprocket. These sprockets will only provide for the turning of the chain at both the top and bottom thus making a loop of the chain running over these two sprockets.

There would be another sprocket mounted on a shaft with its teeth meshing with the chain links. This sprocket would be placed in the centre of the wall height. So for any step taken the vertical translational motion will be converted into rotational motion.

This shaft will also have a Gear wheel mounted on it along the length so that the gear turns along wih any rotation of the sprocket.

There will be an exactly same arrrangement in the reverse order on the other side with similar engagement.

This means that the gear on shaft one will engage with another gear mounted on the second shaft which also has a sprocket mounted on it as in the first arrangement.

These two gears will be having the appropriate gear ratio so as to give the displacement in the ratio required. Here it is 4 : 16. The gear 2 will rotate the sprocket which will mesh with the chain with exactly the same arrangement on the second side.

The sprocket and chain on the lift platform side will thus provide the required lift of the platform for every step taken on the step side. The chain would be running over two smaller supporting sprockets placed on the two vertical ends here too so as to form a flexible loop of the chain and also the platform will be fixed to some links from outside.

And yes the traversal of the platforms and chains will be locked at both top and bottom ends for both the step side as well as the platform side to avoid overturning.

There can be a Ratchet mechanism at either the top or bottom supporting sprockets to eliminate any backward motion or fall.

This arrangement can work for the requirement mentioned.

gohm

Can you use counter weights?

Yes, I don't see a problem with counter weights.

Thanks- Kyle

Rohan_sK

How about using two pairs of Chain and Sprocket to achieve the type of motion mentioned.

The Step platform would be attatched to some links of the chain permanently which would move the chain by certain distance per step taken.

The chain would run vertically along the height of the wall and at the both top and bottom it would run over a turning sprocket. These sprockets will only provide for the turning of the chain at both the top and bottom thus making a loop of the chain running over these two sprockets.

There would be another sprocket mounted on a shaft with its teeth meshing with the chain links. This sprocket would be placed in the centre of the wall height. So for any step taken the vertical translational motion will be converted into rotational motion.

This shaft will also have a Gear wheel mounted on it along the length so that the gear turns along wih any rotation of the sprocket.

There will be an exactly same arrrangement in the reverse order on the other side with similar engagement.

This means that the gear on shaft one will engage with another gear mounted on the second shaft which also has a sprocket mounted on it as in the first arrangement.

These two gears will be having the appropriate gear ratio so as to give the displacement in the ratio required. Here it is 4 : 16. The gear 2 will rotate the sprocket which will mesh with the chain with exactly the same arrangement on the second side.

The sprocket and chain on the lift platform side will thus provide the required lift of the platform for every step taken on the step side. The chain would be running over two smaller supporting sprockets placed on the two vertical ends here too so as to form a flexible loop of the chain and also the platform will be fixed to some links from outside.

And yes the traversal of the platforms and chains will be locked at both top and bottom ends for both the step side as well as the platform side to avoid overturning.

There can be a Ratchet mechanism at either the top or bottom supporting sprockets to eliminate any backward motion or fall.

This arrangement can work for the requirement mentioned.

Rohan,
So, if I wanted to hide the gears in the wall, I would have to make the width of the wall about the same size as the width of the largest gear?

Thanks-Kyle

@Kyle :

So, if I wanted to hide the gears in the wall, I would have to make the width of the wall about the same size as the width of the largest gear?

Kyle, there was no input regarding the purpose or the place for which the wall was required and so anything about the width was very unclear. You had not meentioned anything regarding the desired thickness or dimensions of the wall.

Regarding the concern to hide the gears yes they may turn out to be wide and as we dont know how thick your wall has to be we can do one thing.

I am sure you must have seen the protrusion in a wall where the column passes. Here the width of the wall is much more than the actual width. A similar protrusion could hide the gear assembly at either end of the wall. The assembly need not be in the center of the wall.

Or you could also place it at the top corner of the wall where such a wider protrusion can be easily accomodated and would not even be heavy on aesthetics. The part of the assembly can be located in the roof slab and partially in the wall.

We do not know the load to be lifted or the purpose of your lift which keeps one from deciding the exact location and dimensions adjustments needed.

Anyway if these options dont help you can always go for something else. All the best.