On 6/4/2013 7:46 PM, Gunner Asch wrote:
On Tue, 04 Jun 2013 17:56:20 -0500, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

Tom Gardner Mars@Tacks fired this volley in news:c6-
:

Yep, ant that would be a good option. I still will figure out how to
get the required push but we;re leaning toward air. Thanks.

Tom,
Not only is air the simpler solution (although I use motorized
positioners, too), but it's just as "springy" as you'd want.

One application I have requires that the pressing rod be able to retract
_instantly_ under explosive force. There's nothing for it, but to use an
air cylinder (with an especially long stroke, in my case) to ensure that
nothing-but-nothing obstructs the travel of that rod if it must be
ejected from the zone by the action of an accident inside the pressing
area.

I.E.-- I might use a 6" stroke for a 2" travel, so that I can make sure
there's not excessive force required to back the rod out of it's zone
when required.


LLoyd

One way Ive used to set a device to pull fast or slow..is to use an
adjustable volume valve..and on a tee next to it attached to the same
port...a solenoid valve that only opens under an emergency condition.
The "trickle" valve will allow the rate of movement to be
adjusted..there is also a certain amount of spring as the cylinder is
being drawn..but if you get an emergency condition..that solenoid will
open wide and bypass that adjustable "trickle valve" and allow full
speed retraction.




Cool!