Motorized Pneumatic Valve

[Blakbird]

Cross posted from Lugnet...

This is not my idea, unfortunately, but it is very clever. It uses a differential and a PF motor to control a pneumatic cylinder and valve. By reversing the direction of the motor (which drives the compressor), you also actuate the switch and change the direction of the actuator. It is less compact than Sariel's autovalve, but I like the concept very much.

Original post:

I haven't posted in this forum since 2008 and haven't built much, but upon
looking at the new 8043 Excavator set at Toy's R'Us, it became apparent that
although the new linear actuators dramatically simplify the process, they are
not the only solution. I call them linear actuators because they are typically
motorized and they extend/retract. It is possible to do the same with
pneumatics....if you add a differential into the system. By doing this simply
forwarding or reversing the motor will extend/retract the pistons.

This is not the ideal execution of the idea and there have undoubtedly been
others who found a different way to do this same thing, but it shows the general
idea. One could obviously incorporate a bigger motor, a different gear ratio,
or even shrink the size of the assembly.

Hopefully this idea will help those of you who still want to use pneumatics do
so. Sorry the youtube video is fuzzy.

-Nathan Bell

Brickshelf

[eMHa]

Clever construction.

Problem could be that the valve can't be put in neutral position!?

[Jetro]

I was just reading it on LUGNET

I particularly like the fact that there is no strain on the motor because it is not stalled

Problem could be that the valve can't be put in neutral position!?

Don't know of any autovalve where that is possible...

[eMHa]

Don't know of any autovalve where that is possible...

e.g.: http://technicbricks.blogspot.com/2010/03/tbs-techtips-30-pneumatic-auto-valves.html

But for sure this takes a heavy load on the parts.