[TheForge] Power hammer questions

[Jerry Frost]

Thanks Bob:

I don't have the appropriate software to convert the patent server documents
to .GIF or .JPG without them coming across in several hundred kb.

I have to make a correction though. It shouldn't be called frostyanything,
it's Harold Massey's 1902 patent. So could we call it the Massey valve or
such?

My ONLY claim on this is having understood the 19th century Brittish english
lawyerese well enough to understand how Massey's valves work.

That said, the sketch is a good enough schematic to see how it works. I'd
suggest anybody wanting to follow this make their own sketches on graph
paper. (I like graph paper . . . A LOT)

As drawn with a simple on/off valve (K) the hammer will do two things.

Work, eg. cycle the ram with good control of the force.

And Not Work. A simple on/off vlave will NOT lift the ram at idle NOR clamp.

Okay, time to sketch. <grin> Duplicate Bob's sketch only put a circle where
the valve (K) is.

To represent the valve (K) and check valve (M) use an open arrow with a
straight line beside it. ( > ) = (M)
                     ( - ) = (K)

The direction of the arrow is the direction air will pass through the check
valve (M) and the straight line is the (OFF) function of the valve (K).
Massey specifies a valve that is a combination of on/off and a check valve.

In the idle position (hammer lifted off the anvil) the valve (M) is pointing
down, stopping compressed air from the bottom of compressor piston (A) from
reaching the top of ram piston (B). However, air compressed on top of
compressor piston (A) will pass through valve (M) as the bottom of (A) is
drawing a vacuum making this the path of least resistance.

Air compressed by the bottom of compressor piston (A) is stopped by the
check valve (M) from going to the top of either compressor piston (A) or ram
piston (B). It can only go to the bottom of ram piston (B) and the
differential in pressure holds the ram at the top of it's stroke.

Point the arrow (M) up and the action is exactly reversed clamping the ram
against the anvil.

The ( _ ) on/off valve (K) controls the ram's cycle or working. As it closes
airway (J) the path of least resistance becomes the airways (H & I) to the
ram piston (B) making it cycle in almost perfect opposition to the movement
of the compressor piston (A).

This is the simplest valving scheme Massey came up with allowing the full
selection of working states for a self contained hammer: Idle/lifted ram,
Clamping and full working/cycling. All three selection's force can be
precisely controlled by the treadle or hand control.

This is ONLY a description of the control valves, not the entire hammer. The
Massey hammer does indeed have balance valves though they're piston port
rather than interupted drive rods.

His 1902 patent  # 707,246. is only a claim for the invention of the control
valves and schemes. The remainder of his hammer is essentially no different
than any other.

The patent server esp@cenet  http://ep.espacenet.com/ uses Adobe as a reader
and I heartily recommend downloading the drawings and especially the text.

Frosty
------------------------
If it ain't forged
it ain't real.
Wrought iron is.
The FrostWorks

Meadow Lakes, AK.


----- Original Message -----
From: <schade@acegroup.cc>
To: <theforge@mailman.qth.net>
Sent: Saturday, March 29, 2003 4:43 AM
Subject: Re: [TheForge] Power hammer questions


> Frosty,
>
> I have been looking at the plan you posted and talking about it with Bob
Smolen. I drew up a quick sketch and posted it at the photoaccess site in
the powerhammer file (frostairhammer).
>
> I drew the basic plan without the check valves. The plan would be much
simpler to build than the Krausehammer. No double rodded cylinder. No
balance valves. No special control valve.
>
> It does seem to be a little too simple really. But on paper anyway it
looks like it would work. I guess both cylinders (pump and hammer) would
have to be the same size since there is no place for "extra" air to exit.
>
> I do have some doubts how it would work with the check valves (M) (not on
drawing). Would it be hard on the motor to be pulling a vacuum every stroke?
>
> I could use some help on the check valves.
>
> Bob Schade
> __________________