Mads

Making an new idle valv.

Recommended Posts

Hey after trying the power hammer pages on Facebook with no luck. I hope someone here got an idea.

So I got this self-contained hammer its old and a Danish designed. But the idle valv is missing. I have tried making one but it is not doing a great job. So I need an idea for how to design a new one or improving the one I got. 

I have attached some pictures and film clip of the hammer and hope someone out there got an idea

 

Mads 

 

20190929_113031.jpg

20190929_112610.jpg

20190929_112624.jpg

20190929_112617.jpg

Share this post


Link to post
Share on other sites

I made this it works a little better...

just some leather and a shim as a spring.

 

There is not a lot of info online about this kind of problems so hope this will be to some help for others:) 

Share this post


Link to post
Share on other sites

Have you searched out the patent drawings? That's just a reed valve. Does it work satisfactorily?

Frosty The Lucky.

Share this post


Link to post
Share on other sites

What is the function of this valve?

My big hammer uses an automotive valve and spring for a one way valve. Its part of the air cushion system.

Share this post


Link to post
Share on other sites

The valv makes the hammer idle.. without it the ram just stayed down. But if I close it and air can't get back then it is the same thing as when I run the hammer full power.

The new valv works better but I still hope to get the ram to idle higher up and give some more work hight.

And some times won't the ram wont go back to idle after a heat and just start clapping the dies...

I haven't  Ben able to find any info on the hammer or the company I think made it. So I need to invent the valv from scratch:) 

 

Share this post


Link to post
Share on other sites

Mads do you have Mark Kraus's book?  It may help.

this sounds like a complicated thing to fix, but some more infl may help. does the hammer have pressuer under the front piston or just on top. a flow diagram would help. the valving for an alldays and onions hammer that pulls a partial vacume above the front ram is very diferent  (and much simpler) from that needed to controle pressurised air/ vaccume that is above the front ram as well as below it like on a sahinla or nazel.

 

Share this post


Link to post
Share on other sites

This shouldn't be a violation of the rules as this is to the US patent office ad a specific patent drawing. 1902 Massey pneumatic power hammer to be specific.

It's a long one, sorry. https://pdfpiw.uspto.gov/.piw?Docid=00707246&homeurl=http%3A%2F%2Fpatft.uspto.gov%2Fnetacgi%2Fnph-Parser%3FSect1%3DPTO1%26Sect2%3DHITOFF%26d%3DPALL%26p%3D1%26u%3D%252Fnetahtml%252FPTO%252Fsrchnum.htm%26r%3D1%26f%3DG%26l%3D50%26s1%3D0707,246.PN.%26OS%3DPN%2F0707,246%26RS%3DPN%2F0707,246&PageNum=&Rtype=&SectionNum=&idkey=NONE&Input=View+first+page

This is from the relatively early days of pneumatic power hammers and about as simple as will function. To set the terms as I've been using them for years without regard to what was used more than a century ago. The main parts are the: power, be it motor water wheel or windmill, this is the driving force. Next is the crank which converts rotary motion to reciprocating motion. Next are the pistons, on the left is the Tup piston, I call the "SLAVE", on the right is piston connected to the crank that converts reciprocation motion to air flow. I call this the "MASTER". Just like old school hydraulic brakes in the Chilton or Motors manuals.

The "CIRCUIT" are the air channels that conduct the air flow. 

Last is the "CONTROL VALVE"

In Fig. 1 the circuit and pistons are shown without control valve. One channel goes from the bottom of the Master cylinder  to the bottom of the Slave cylinder and another from top to top. This circuit will work just fine but the hammer is either on or off, speed control would by controlling the power, water to wheel or speed control of motor, etc. When off the tup will settle to the anvil. Initially it will stop where ever the Master piston stops in it's stroke and settle as pressure leaks off.

The fig 1 hammer would work well but on the same level as a trip. On or off crude speed control. Period. Dot.

Figs. 2, 3 & 4. show various channel and valve placements and types, it's not functional as drawn, think of it as concept sketches.

 Fig. 5 shows the basic air circuit I'd planned on using. It's figure 1 with a control and check valve in the lower air channel. Open the valve and compressed air begins to cycle to the Slave cylinder, as the Master moves down the Slave is forced up and visa versa. When the control valve is closed air is stopped and the tup stops, the check valve keeps the bottom of the Slave cylinder under pressure and the tup stays up at idle. The pressure developed by the Master on it's up stroke escapes through a pressure release valve, represented as h in fig. 5. 

Argh, saw this after submitting the post. If you select "Full Document" on the patent server page the rest of the drawings and descriptions download. If you're going to get into this it's easier to print it out and use multi colored highlighters. 

These old pneumatic hammers operated on surprisingly low PSI, on the order of 8-12 psi. 

I could be wrong but I believe this or similar patent drawings are what Mr. Krause based his design on and it's a good one.

I can't find it but the one I settled on is slightly different. If you place a cross (X) channel between up "h" and down "i" channels in Fig. 1 and place the control valve in the X channel, closing the valve causes pressure to cycle to the Slave cylinder and the hammer cycles. Open the control valve and pressure follows the path of least resistance and flows from top to bottom of the Master cylinder without effecting the Slave.  In it's simplest form a basic 1/4 turn ball valve makes it work just fine. However without a way to keep pressure to the bottom of the Slave the tup will rest on the anvil at idle.

So a check valve in the control valve will prevent air from flowing from bottom to top of the circuit on the down stroke but we don't want it to just build pressure or it'll either stall the motor or break something so the check valve has to have an escape over bypass. Then another check valve in the up circuit after the cross circuit and as long as the Master cycles the tup idles in the up position. This gets more complicated but can be modeled and debugged in ABS plastic.

If you want one that'll clamp it requires a pressure reservoir and different valving.

Things like spool valves and complex air channeling almost certainly came about because of patent law a company that wanted to build it's own power hammer had to make enough changes to satisfy the law I'm pretty sure this is why almost all the later patents have "Improved" in the title.

I sure wish I knew what happened to my drawings and the patent drawings I was modeling from but that comp has been dead for some time and I found a Little Giant and I don't need to build one. Be fun though.

Frosty The Lucky.

Share this post


Link to post
Share on other sites

hi Frosty , the valving shown above does clamp...I have one of those hammers.clamping just needs air to the top of the slave piston and none below. my suck and blow hammers with only air above the slave piston all clamp as well...its not very useful though!

Share this post


Link to post
Share on other sites

After I realized I wasn't looking at the complete document and looked through the rest of the drawings I saw this design clamps. Perhaps I was thinking of delivering a dead blow, it's been years since I've talked to Bob Bergman of the Postville Blacksmith shop. Bob is or was the go to guy for rebuilding pneumatic power hammers. 

By "suck and blow" do you mean single stage pistons that only work on the side away from the connecting rod? Maybe a syringe is a good working image?

Frosty The Lucky.

Share this post


Link to post
Share on other sites
13 hours ago, Frosty said:

After I realized I wasn't looking at the complete document and looked through the rest of the drawings I saw this design clamps. Perhaps I was thinking of delivering a dead blow, it's been years since I've talked to Bob Bergman of the Postville Blacksmith shop. Bob is or was the go to guy for rebuilding pneumatic power hammers. 

By "suck and blow" do you mean single stage pistons that only work on the side away from the connecting rod? Maybe a syringe is a good working image?

Frosty The Lucky.

yes exactly that. the alldays and onions hammers and pilkingtons work like that, bigger pistons and a simpler valving.

Share this post


Link to post
Share on other sites
On 11/2/2019 at 1:25 AM, jason0012 said:

I want to know more about it. Where was it made?

It was build here in Denmark. the seller told me it was two brothers and after on spend some time I the US he saw some airhammers and then went back and they started making them. There is two sizes, this I the big one and the take is 50kgish and it hits super hard.

I don't know how old it is but I can't find any info on the company, all bolts are in inches  so it has to be old;) I

I don't owne the book where can it be found?

I have been working a lot lately and there is a lot to read up on this thread already. But I will try to take a foto tomorrow an draw a flow chart on it:) 

Thanks for all the inputs

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.