Locking Aparatus For a Vertical Guided Head 1

[utson]

Hello everyone,

As it can be seen in the picture, we have a weighted head guided vertically by linear ball bearings, which is supposed fall down freely with the weight that it carries. We are using a crane to lift it but while it's already lifted sometimes we need to do some setting just under that head. Hence to be more secure, we are looking for an aparatus that we can use it between head and guided shaft to stop the head on any point of 3 meters guided shaft. Since we can not thread or do any kind of modifications on the shaft, we need a detachable tool which can be used and removed easily.

Have you got any tool in your mind or a suggestion to accomplish it?

 

[MintJulep]

Screen door hold open clip.

 

[MikeHalloran]

Die safety blocks, similar to these:

http://www.stampersstore.com/safety/press_safety_blocks.htm

or cribbing (watch a rigger).

Mike Halloran
Pembroke Pines, FL, USA

 

[tbuelna]

Any type of friction clamp attached to the smooth shafts will not provide a fail safe travel stop. If people are working under/near the moving head/load, then you need some sort of adjustable hard travel stop that can be positioned directly under the load so that it can only fall a very small distance. You need to check OSHA requirements for design factors of safety with this type of situation.

 

[utson]

Since we don't have any other point close to system to fix the stopper, we were looking for a tool that can be directly positioned under the moving head/load to stop it temporarily as tbuelna says. First we were thinking about a cylindrical rubber stopper like a open linear bearing (

http://www.zjlinearbearing.com/product/1-4-1b.jpg

) which can be positioned on shaft just under the head easily on every each point to stop it. But since the moving head will be around 100 kg and the shaft will be relatively lubricated because of the bearings travel on it, this friction based solution is worrying us.

For the other suggestions, honestly i couldn't understand how we can apply it

 

[hendersdc]

Could you hang a chain next to the unit that was long enough to cover the range of travel? The head could be attached to any link in the chain by using a shackle to attach it to a lifting eye or sliding the chain link through a slot in the head or an attached bracket. This would give you steps every couple of inches depending on the chain size you use.

 

[MikeHalloran]

>>> honestly i couldn't understand how we can apply it <<<

Then, it's time to start your design again.

Safe operation and maintenance is not something you apply to a design as an afterthought.



Mike Halloran
Pembroke Pines, FL, USA