Threaded Norman Toolpost

Thanks for taking time to explain John. It's much clearer now how the clapming works. It's my first time seeing this design as all the ones I came across online were of the split holder type. This seems like a better design, I like it.

An excellent method to provide positive clamping with instant release, I first used it on a Dore Facing and Boring head to retain the tool, it was the method described on the plan.

Used it a couple of years ago to lock a rotating turret type 8 tool toolpost to a stop on my cnc lathe.
Tool turret pictures in my album.

Emgee

....Still trying to get my tired old brain around the locking pin mechanism.......what anchors the ends of the thread?....one end is obviously a hex socket normal head, but does the other end have to thread into the block?

..........A bit cheeky of me, but could you post a rough cross section please?

looking at your photos, left and right, the tail end of thread looks like it threads into a washer larger in diameter than the pin sections.....Is this right?.......what stops that washer from revolving with the thread?

Edited By Bob Stevenson on 10/08/2019 22:53:55

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John,

I have been searching for that Van Norman patent, and failed

[found several others by him but not that one]

Then I stumbled across a note by you, on another forum:

[quote]

Hi Guys,

I can't find the original references to the "Norman Tool Holder" But the original didn't use a bolt to clamp the holder to the post. That drawing in the PDF is modified to use a clamp bolt.

The original design used a split pinch clamp that actually closed on the post directly. Yes it had a screw through it which pulled the two half's of the clamp together. This also allowed a further modification of a handle to clamp the holder without any tools.

[/quote]

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So, my question is: Did you find the original references ?

and, if so, could you please share the patent number ...

I am familiar with the clamping method: I would just like to have a copy of the relevant patent on file.

Thanks

MichaelG.

Hi Michael,

Unfortunately not ! I did find the original info on line quite some time ago, but I've been through a couple of hard drives since then and my backups are not all that they should be. Over time I've lost a lot of information that I can no longer find on line.

Have you looked at the USA patents office ? I think you can search it by both name and date. The earliest reference I could find was some time in the late 1880's. But I'm blessed if I can remember exactly.

Thanks for the reply, John

I tend to use espacenet, which has good worldwide coverage and quite flexible search criteria ... but I can try on uspto.

Several tool-holding patents are available, around that date, in the name of Van Norman, but I have yet to find the one for this elegantly simple design. ... Perhaps it is hidden within one of the others, as an alernative 'embodiment'.

[or perhaps I was just having a bad day]

MichaelG.

Hi Michael,

I do recall that was how I discovered about "Van Norman" Lathes.

I must admit to not being able to rediscover it. If you do come across it, please let me know.

The clamping arrangement of the split sleeve machined to the radius of the parent bore is so good, that it will be included in a project that i have in mind.

Presumably, the same van Norman as the company that produced the greatly respected boring bars for engine cylinders?

Howard

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This looks a promising list, John **LINK**

http://vintagemachinery.org/mfgIndex/detail.aspx?id=2109&tab=7

MichaelG.

Hi,

for what it's worth the clamping mechanism is described by GHT in his book 'Dividing and graduating', page 59 in my copy. It is used to clamp the spindle of his Versatile Dividing Head.

Dave