To all the mechanic savvies out there

[Embee]

I'm in need of some help.

I'm looking for a set of gears that will allow me to rotate a smaller gear, set perpendicular to a much bigger static gear. This way, when an axial moment is performed on the smaller gear, it will rotate around the bigger gear which will remain static. Something set up like this:

Spoiler:

Except that the teeth of the gears have to point ds, not inwards, as shown in the image.

A few questions:

• -Is this possible?
  
  -If yes, what kind of gears do I have to use in order for it to work?

The idea is to have a grip set perpendicular to a hose, using the gear system to rotate around the hose freely.

Any ideas?

EDIT: Also, does anyone know of any EXISTING product that works this way? In other words, a certain object rotating around another static object in a system.

[MrFancypants]

I don't really understand what you are trying to do, but as for your last question: a pintle and gudgeon might work if you just want to rotate the top part and keep the other part static. Gears are usually used to transmit motion, hinges allow or restrict motion.

[Mr. Matt]

Lego Technic is the extent of my expertise in this matter I'm afraid. But perhaps if you described what you were trying to achieve it would make it easier for those who may have the answer to help you?

[Mihail]

What are you trying to do? Because it would be much easier in most applications just to use a chain drive.

[Embee]

I made some quick sketches, aiming to explain it better to you guys:

Spoiler:

1) This is a normal firefighters hose, with a handle that allows them to regulate the amount of water that comes out of it. The very end of the hose requires a moment (physics term) in order to regulate HOW the water comes out (either a large screen or a precise, concentrated flow). Problem with this is, there's only one handle and firemen often have to hold it in an awkward way, like this:



Sometimes, they even have to hold the hose with two men.

2) My aim is to add a grip onto the hose (either modular or integrated into the hose, I can choose), with the aim of giving a strong and stable holding position for the firemen (see 5) in which the grip can rotate around the hose so it's easier to hold whenever the fire is located much higher, to avoid awkward positions with a static grip). Also provided is a handle which you have to rotate in order to move the grip around.

3) This is the front view of a simplified mechanical proposition on how this stuff works. The smaller gear (under the grip) is attached firmly to a large bar, which is in its turn attached to a handle. Whenever you turn the handle, you turn the large bar, which turns the small gear, which turns AROUND the static gear. The latter should not be able to move (fixed to the hose) the "M" with the arrow stands for moment.

The small gear should somehow stick to the large gear. I think I'm going to use some spring device which pushes the small gear towards the static gear. That way, if I want to move the grip around the hose in a much higher speed, all I have to do is raise the bar a bit, which will raise the small gear, detaching the mechanism, move the grip all the way to the wanted position and release the bar, which will be pushed back onto place by the spring devices. This will be faster than turning the handle all the time, but less precise.

4) This is a poor 3D drawing of how the the gears are set up. Turning the handle should turn the small gear around (in this situation, to the right of the house. You're facing front right corner of the set up), consequently turning the grip too.

That way, you can turn it around should you have a particular position you wish to hold the hose in.

What I'm looking for now: do you know of any existing product/device/ ANYTHING that works in an analogical way (turning a small gear around a larger static gear with a handle)?

And secondly, but not important, is this a good system? Can I improve it and make it easier? Are there any constraints to this system, or is it flat out impossible?

[MrFancypants]

In your version the rotating handle is disconnected from the valve, right? Then you don't need much more than friction and a simple screw mechanism. Take a look at your shower, most likely you have a showerhead-holder that is moveable if you rotate a little knob. Apply the same principle to your handle, make sure that the friction is sufficient to keep the handle in position regardless of which way the hose is pointed under pressure but not high enough to damage the nozzle. Then design the screw accordingly.

Potential problems are pressure variations in the hose (that is why it is important to apply the thing to a rigid body like the nozzle) and the effect of water on friction.

You could improve on the system by integrating the rotating handle with the pressure valve.


Is this homework for a class you're visiting?

[Nemmerle]

It sounds like you just want a handle connected to some sort of circular clamp that'd grip onto a bit of the pipe; preferably something rigid glued to the pipe rather than the pipe itself, I suppose.

[Embee]

Originally Posted by MrFancypants

In your version the rotating handle is disconnected from the valve, right? Then you don't need much more than friction and a simple screw mechanism. Take a look at your shower, most likely you have a showerhead-holder that is moveable if you rotate a little knob. Apply the same principle to your handle, make sure that the friction is sufficient to keep the handle in position regardless of which way the hose is pointed under pressure but not high enough to damage the nozzle. Then design the screw accordingly.

I already thought about a friction part, but that only applies to how I'd be able to "clamp" the whole item onto the hose. Your idea isn't bad, but it doesn't accord to the criteria of my exercise: I have to improve a certain object in a domain (here, it is firefighting department and the object of my choice is the hose, mainly due to the complaints of firefighters), with either a clutch system, or an adjustment system including both a precision adjustment or a greater adjustment (much like those compasses):

Potential problems are pressure variations in the hose (that is why it is important to apply the thing to a rigid body like the nozzle) and the effect of water on friction

This is indeed an issue. I've been thinking of connecting the grip to the head of the hose, since you don't need that much space between the handle and the grip (the smaller to a certain point, the more force you can apply to keep the hose steady). Either that, or like Nem said, "gluing" it to the hose. Perhaps design it to be slightly smaller than the diameter of the hose, so the water pressure would keep it tightly locked in place. This could have a lot of problems as a consequence, so I need to research the latter option a bit more.

You could improve on the system by integrating the rotating handle with the pressure valve.

I don't really know what you exactly mean... As such so it (the handle) can only be turned when pressed in, or that the smaller gear turns when pressed?

Is this homework for a class you're visiting?

Yes, I have to do some designing for a new improved system for school. Unfortunately, I also have another class where I have to do a lot more, and more classes like physics and mechanics. My knowledge about mechanics is very, VERY limited, so I'm inevitably falling short (in time and knowledge) for one of my classes, which happens to be this one.

Initially, I posted in this thread to know if there are any other products working in an analogical way (like you have to turn a certain handle around so a part moves around another static part). I need to use a comparison with which forces and moments work on the parts and how it gets into movement, etc... and hand it in. So if anyone knows of anything that works like that, please tell me the name of it.

Originally Posted by Nemmerle

It sounds like you just want a handle connected to some sort of circular clamp that'd grip onto a bit of the pipe; preferably something rigid glued to the pipe rather than the pipe itself, I suppose.

Yes. Either that, or I'll have to connect the grip (speaking about the whole item) to the head to prevent it from exercising a too great torsion on the pipe and tearing it.

[MrFancypants]

Originally Posted by Embee

I don't really know what you exactly mean... As such so it (the handle) can only be turned when pressed in, or that the smaller gear turns when pressed?

Maybe I still don't understand exactly what you try to do. The way I see it you have a nozzle, then a valve to adjust the waterflow and a handle. From what I understood your main goal was to be able to rotate the handle around the nozzle so that it is more ergonomic. For that intend you could either use a handle that does not change the valve setting or a handle that can both be rotated but that also changes the valve. In your drawing the forward grip seems to regulate pressure and the rear grip just needs to be adjustable.

You wouldn't really need gears just to rotate the handle around the hose.
But if that's a requirement of the exercise I suppose you could look at planetary gear sets where you replace the central shaft with the hose and power one of the planet gears using the sort of bevel gear from your OP. The planetary gear would serve as fixation, the other as drive (or leave the drive gear out and rotate the outer part manually). Don't forget to fixate the rotating part in axial direction.

Originally Posted by Embee

Initially, I posted in this thread to know if there are any other products working in an analogical way (like you have to turn a certain handle around so a part moves around another static part). I need to use a comparison with which forces and moments work on the parts and how it gets into movement, etc... and hand it in. So if anyone knows of anything that works like that, please tell me the name of it.

Richard Gattling invented a device where cranking a handle rotated objects around a static central shaft.

[Embee]

Originally Posted by MrFancypants

Maybe I still don't understand exactly what you try to do. The way I see it you have a nozzle, then a valve to adjust the waterflow and a handle. From what I understood your main goal was to be able to rotate the handle around the nozzle so that it is more ergonomic.

Well, the idea is to only add a movable grip. I'm actually not even touching the nozzle or its mechanics. The rear grip is being added so firemen can hold the grip and the handle at the nozzle to keep a more ergonomic and stable posture when using it. Since the objective is also to be able to adjust the new item, I thought about making the grip adjustable with gears.

For that intend you could either use a handle that does not change the valve setting or a handle that can both be rotated but that also changes the valve. In your drawing the forward grip seems to regulate pressure and the rear grip just needs to be adjustable.

Yes, exactly. The forward grip remains like the original one. The rear grip is what I add and only has an ergonomic function and does not affect the forward grip in any way, nor its way of working.

You wouldn't really need gears just to rotate the handle around the hose.
But if that's a requirement of the exercise I suppose you could look at planetary gear sets where you replace the central shaft with the hose and power one of the planet gears using the sort of bevel gear from your OP. The planetary gear would serve as fixation, the other as drive (or leave the drive gear out and rotate the outer part manually). Don't forget to fixate the rotating part in axial direction.

Good thing you've pointed that to me. I think it's a good system, actually, because the outer big ring provides a much better hold for the grip, compared to when it's attached to a smaller ring. The only problem though is how I'll be able to make it adjustable in a fast motion instead of rotating it around the ring (also requirement of the exercise)

Richard Gattling invented a device where cranking a handle rotated objects around a static central shaft.

I'll look into that, thanks.