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Who developed the J-series collets (1J, 2J, 3j, etc.)

Cal Haines

Diamond
Joined
Sep 19, 2002
Location
Tucson, AZ
I did some searches trying to find the origin of the J-series collets (1J, 2J, 3J, etc.) and have come up dry. Does anyone know?

Thanks!

Cal
 

David Ferguson

Aluminum
Joined
Aug 13, 2008
Location
Paso Robles, CA
According to Wikipedia:

A collet system with capabilities similar to the 5C (originally a proprietary system of Hardinge) is the 2J (originally a proprietary system of Sjogren, a competitor of Hardinge, and which Hardinge later assimilated).
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MrStretch

Cast Iron
Joined
Mar 20, 2017
Bullwinkle J Moose?

Makes sense that they used J instead of S because S series (Stark) collets already exist.
 

boslab

Titanium
Joined
Jan 6, 2007
Location
wales.uk
I’d guess johanason or jarno, the only ones I know beginning with j as I guess they were pre jacobs
Mark
 

Cal Haines

Diamond
Joined
Sep 19, 2002
Location
Tucson, AZ
Sjogren Collet Chucks and J-series Collets

According to Wikipedia:

A collet system with capabilities similar to the 5C (originally a proprietary system of Hardinge) is the 2J (originally a proprietary system of Sjogren, a competitor of Hardinge, and which Hardinge later assimilated).
5C isn't a "collet system" and neither is 2J. Hardinge markets the "C-series" collets, which include the common 5C collet. The 5C collet is very similar to the 1J (not the 2J); they have the same OD and thread, but the 1J is shorter and has a different nose angle.

Here's a post that has an explanation of the development of the J-series collet:
The 1J collet design was not a Hardinge idea at all. The chuck was invented by Knut Sjogren of Los Angeles, CA and the patent was filed June 6, 1929. The original collets were size 1, 2 and 3 Sjogren. Hardinge made collets for every application and invented their own designations for the collets of other companies. The 1J, 2J and 3J designations date from the time Hardinge began making collets to fit the Sjogren chucks.

Sjogren's chuck patents were not assigned to Hardinge, so it was sometime after 1943 or so that Hardinge made a deal to add their name to the chucks and market them as a Hardinge product. That was probably also the time when Hardinge added the 5C collet chuck to the Sjogren line. At some point they stopped selling the 1J collet chuck, and that was Hardinge's bright idea. Nobody has any trouble finding 5C collets, more than 100 years after they were first made. The only Hardinge-Sjogren catalog I have is from 1989. The chucks could then be bought in 5C, 2J, 3J, 22J and 35J collet sizes.

...

To which I can add the Mr. Sjogren's full name was Knut Robert Sjogren, a Swedish immigrant. Born 20 Oct 1882, died 2 Feb 1953. He's buried in Los Angeles (link).

His company was the Sjogren Mfg. Co., 1637 E Slauson Ave., Los Angeles, CA.

He recieved four patents for collet chucks:
  • 1,789,601 Chuck - patented Jan 20, 1931
  • 2,293,176 Collet Chuck - patented Aug 18, 1942
  • 2,311,258 Collet Chuck - patented Feb 16, 1943
  • 2,342,903 Lathe Attachment - patented Feb 29, 1944 (lever mechanism to operate 2,311,258)
The first two were for the handwheel operated chuck. The second two were for the lever operated speed chuck. Interestingly, the first patent, filed in June, 1929, doesn't use the word "collet" instead, it's called a "nose attachment".

It's not at all clear that Hardinge "assimilated" Sjogren. They may have simply bought the rights to manufacture and distribute Sjogren's speed chuck. The December, 1935 issue of Machinery has a short article about the "Sjogren Speed Chuck", with no mention of Hardinge.

The Tool Engineer, Volume 10, Page 72, March, 1941, page 72 contains this mention of the chuck:
HARDINGE SJOGREN SPEED COLLET CHUCK

The Sjogren Speed Collet Chuck will be among the items displayed by Hardinge Brothers in Booth 127. An almost effortless turn of the hand wheel in the desired direction is said to open or close the collet. Thus work may be quickly released or gripped. No time need be wasted in looking for a wrench or key since the handwheel is a part of the chuck. Designed for tool room and engine lathes the chuck may also be adapted to milling machines, turret lathes, grinders, and special production machines.

So sometime between 1935 and 1941, Hardinge began marketing the chuck. Note that the 1942 patent, which is the basis for the popular Hardinge-Sjogren Speed Chuck, was issued in Sjogren's name after the 1941 article in The Tool Engineer. Similarly, the 1943 lever collet chuck patents are in Sjogren's name with no mention of Hardinge.

Cal
 








 
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