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Post by modeng2000 on Mar 29, 2008 17:35:59 GMT
I need a spring washer that is about 20mm dia with a 3mm hole in the center and is saucer shaped. The idea is to use the washer in compression much like a coil spring. I believe I have seen washers with a series of radial fingers for the spring action.
It is looking very much like I will have to make it so any ideas please? Can I soften a piece of clock spring and after filing to shape harden and temper to get what I need?
John
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Post by circlip on Mar 29, 2008 18:08:15 GMT
The type of "spring" you are referring to is normally used as a quick assembly aid for retaining shafts or assemblies onto shafts, IE wheels on baby buggies. Don't know if you can get them in"sample" quantities, you could try Lewis spring - no affiliation etc. I think the originals could have been made by Terry's or Spire fasteners. If you do try some home cooking, you need to make them like a starfish - the legs need to be able to flex freely. Only other type are "Disc springs" but will probably be too strong for your application. Regards Ian.
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Post by GeorgeRay on Mar 29, 2008 18:33:45 GMT
It sounds like what you need is a belleville washer. These are commercially available. Have a look at www.assocspring.co.uk/pi_belspr.asp. whether they can supply exactly what you are after I dont know. Belleville washers dont have fingers though they are known as disc springs because that is what they are. Fingers would probably make them quite weak in compression. If you have apiece of clock spring you could probably make one by softening then drilling the central hole, turning to the diameter you require and then pressing into a cone and then rehardening and tempering.  |
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paul
Member
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Post by paul on Mar 29, 2008 20:53:06 GMT
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Post by modeng2000 on Mar 29, 2008 21:04:12 GMT
Many thanks fellas, the help is much appreciated. I just could not recall the name of this type of washer.
So as not to leave you in suspense, the application is to hold down the rotating part of the reversing valve for my De Winton type oscillator. I think it would look much better than a coil spring that sticks up from the top of the engine block.
John
Ps. I have just looked up the thread on this board and found that I had contributed to it. My memory can't be what it should. I now reckon that I could probably get away with the strip type of springing so I'll try that first.
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paul
Member
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Post by paul on Mar 29, 2008 21:07:39 GMT
Wooo.... sounds like there's some progress there John |
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Post by modeng2000 on Mar 29, 2008 21:13:36 GMT
Yes Paul, when things are a bit more together I'll post a picture or two.
The engine is about finished but has yet to be run so I still have my fingers crossed. It sits nicely on the side of the boiler so the engine block should warm up and reduce condensation.
John
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Post by circlip on Mar 30, 2008 6:29:52 GMT
Yes, Belville washers and Disc springs are EXACTLY the same animals, used to make millions of the little b***ers from about 1/4" to 6" in dia. Difference in names is that Belvilles were the trade name for the ones that were made in TLOTF, Disc springs was the name given to them by Anderton springs who made them in this country, very weak way of getting round the US patents by calling them summat else. Yes Paul, the type of clip with the fingers on are meant to grip the shaft that's why I suggested the fingers pointing outwards although I've seen both types with non dig in features IE outer diameter and inner with a rolled edge. Still think Belvilles/Disk springs are going to be too strong for this application. Ian.
Edit. The type I have seen are like the one posted on the Havoc/Paul thread but with six legs, like a starfish like I already said.
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Post by modeng2000 on Mar 30, 2008 15:53:36 GMT
Ian,
I have used a flat spring of phosphor bronze to seat the reversing valve. As you said a disc spring would be far too strong. I had not realized that so little force was required.
Thanks again.
John
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