What bit is this?

[Bob Easton]

This bit came along in a box of other stuff one day. It has no makers marking. The only marking is "7" for its size, 7/16 inch.

It is distinctively different than the Russell Jennings and Irwin patterns in that there are no spurs pointing toward the tip. Instead, the tips of the flukes are turned back toward the shank.

What is this pattern called, and (bonus points) who might have made such bits?
... and (more bonus points) what are the pros and cons compared to the venerable Russell Jennings pattern?

FWIW, this exemplar cuts a very smooth hole and is accurate to its size.

http://www.bob-easton.com/blog/wp-content/uploads/2010/02/what_bit_is_this.jpg

[Robert Rozaieski]

It's called a gedge (sp) bit or Cooke's patent bit. They are relatively rare but really nice because you can bore completely through a board without any blowout on the exit side. I'd love to find a set myself.

[Jeff Burks]

8,162 (http://www.google.com/patents?id=J-FHAAAAEBAJ&zoom=4&dq=8162&pg=PA1#v=onepage&q=&f=false)
RE2,513 (http://www.google.com/patents?id=idEAAAAAEBAJ&zoom=4&dq=RE2513&pg=PA1#v=onepage&q=&f=false)

Related links on this subject
Full Chisel Blog (http://www.fullchisel.com/blog/?m=200805)
Old Tools Archive (http://www.swingleydev.com/archive/get.php?message_id=112027&submit_thread=1)
John Gedge (http://books.google.com/books?id=Q_0KAQAAIAAJ&lpg=RA1-PA89&ots=PLVFTzZV3J&dq=Gedge%20patent%20auger&pg=RA1-PA89#v=onepage&q=&f=false)
Ransom Cook (http://www.onlinebiographies.info/ny/sara/cook-r.htm) is even on Wikipedia (http://en.wikipedia.org/wiki/Ransom_Cook)

[David Gendron]

I think they are also use full to start holes at an angle, and that chair makers sometime swap the spoon bit for these! But please correct me If I'm wrong!

[Bob Easton]

I should have known to search through Stephen Shepard's stuff, esp this one: http://www.fullchisel.com/blog/?p=106

Jeff, you're quite the patent hound. Do you hold any yourself?

Bob and David, you're both right about these being sweet, clean, bits. It's easy to see how they would work very well for angled holes.

Thanks all!

[Jeff Burks]

No Bob I don't own any patents, rather I just find them to be an incredible primary source of information worth looking into. You just never know what you will find when you dig around a little bit. This is especially true with the wide range of sources that have become available in the last few years via the Internet.
For example:
James Swan Patent 115,541 (http://www.google.com/patents?id=AmBlAAAAEBAJ&zoom=4&dq=115541&pg=PA1#v=onepage&q=&f=false) which is related to this discussion.
Or even this faucet (http://www.google.com/patents?id=kX9sAAAAEBAJ&zoom=4&dq=32699&pg=PA1#v=onepage&q=&f=false)

I don't have any good information on the Gedge patent because it was issued in the UK and I just don't have a lot of patience for Euro patent search. There are however numerous references to him via Google Books (http://books.google.com/books?lr=&as_brr=0&q=Gedge+auger&btnG=Search+Books&as_drrb_is=b&as_minm_is=0&as_miny_is=1840&as_maxm_is=0&as_maxy_is=1930).

Those looking for bits of this type could visit eBay and search the title & description under the Collectibles >Tools, Hardware & Locks >Tools category using the following keywords:
Cook
Gedge
Gilpin

[David Gendron]

Thank you Jeff, it all good info!

[Bob Easton]

Closer examination to all the references Jeff provided convinces me that this is a Swan bit. Swan's improvement (over Cook's) was to extend the cutting edge all the way into the screw ... and that is indeed what I have.

Thanks again Jeff.