[TheForge] Re: Krause/Nazel type air hammer

[theforge@mailman.qth.net]

>BTW, can you point me to an online drawing of a "spool valve"?  I
>don't know what that term refers to.
>
>- Mike
>
>-- 
>Michael Spencer                  Nova Scotia, Canada 
___________

mike,

i put up a drawing of a spool type valve at theforge photo site in the powerhammer folder. i also drew up the krausehammer circuit using two-three way valves. following this is a step by step to follow the drawing. i posted this last week but it may have gone into the black hole. you might want to print it and follow along with the drawing.

bob
_______

1.turn on

2. pump cylinder goes up and pushes all the air in it out thru the open exhaust port in the top three way valve.

as the pump cylinder reaches the top of it's stroke the "bottom balance valve" opens and air is drawn into the pump cylinder. (balance valves are machined into both ends of the pc rod).

3.pump cylinder goes down pushing all the air in it thru the exhaust port of the bottom valve. this air continues thru the one way valve (check valve) to the bottom of the hammer cylinder which raises the hammer.

4. at idle this cycle continues. the hammer is pushed up by the downstroke of the pump cylinder. the hammer then falls due to gravity. puff fall puff fall etc.

5.to run...both valves are actuated (pulled down in this case) simultaneously. as the exhaust port in each valve starts to close the ports in each valve leading to the top and bottom of the hammer cylinder are opened a corresponding amount. as the valves are opened further the stroke (and force) of the hammer increases.

at the bottom of it's stroke the pump clyinder is opened thru the balance valve on top to draw in air for the next power stroke.

6. the check valve allows the air of the falling pc to raise the hammer cylinder but keeps the rising pump cylinder from sucking the hammer back down.