Thread Cutting 100 Years Ago.

[Boringgeoff]

Morning all,
I am researching machining methods in use at the end of the 19th century in the USA. Specifically cutting a male and female thread on two mating parts where the final product has to have a particular orientation. As an example I am using the Lowentraut Combination Tool. This consists of three parts, the wrench,the handle and the crank. The crank has a tapering square shank which locates in a corresponding socket in the rear of the handle. The handle connects to the wrench by screwing onto a threaded stud. To ensure the crank is always aligned with the wrench the thread needs to be cut the same on each tool so that All the cranks can be made with the same orientation.
Clear as mud?
In my mind, the cutting head is stationary as is the part to be threaded which is clamped in a carriage (?). The two parts are brought into contact then one or the other is rotated the required number of times to cut the thread then reversed off and the process repeated on the next piece, resulting in a production run where multiple pieces all had a thread starting at the same position.
As you can easily see, I have never had anything to do with a lathe.
My question is this, did they have the expertise in the USA to do this in 1894?

Thanks for your time.
Geoff.

[Ueee]

I cannot say for sure but I would say yes. My leblond is only 20 years later than that and it has full thread cutting capabilities, chasing dial, 36 standard threads from the gearbox, and even optional gears (5) for metric threading.
There is a YouTube vid of a bloke threading on a pre 1900 lathe somewhere, I'd say the tech was there.

Cheers,
Ew

[toolman49]

G'Day Fellas,
As a kid I watched my grandfather (a blacksmith by trade) cutting threads on an ancient death trap of a lathe which would have been of at least pre 1900s vintage, the machine obviously had no threading dial as he used chalk marks on the chuck and leadscrew to time successive cuts. From memory the old bugger did a pretty good job with a fairly crude machine.
Regards,
Martin

[j.ashburn]

G'Day Fellas,
As a kid I watched my grandfather (a blacksmith by trade) cutting threads on an ancient death trap of a lathe which would have been of at least pre 1900s vintage, the machine obviously had no threading dial as he used chalk marks on the chuck and leadscrew to time successive cuts. From memory the old bugger did a pretty good job with a fairly crude machine.
Regards,
Martin

Yep thats what they did seen it myself.1st cut done then lathe stopped. half nuts lever wired to saddle to stop jumping out of mesh cut taken in steps reversing the rotation to the start of the next in cut.
Before Whitworth most manufacurers cut their own threads to suit them selves. Some were free hand cut with a graver.Whitworth brought a standard to promote inter change ability in the emerging industrial expansion.

[pipeclay]

Is your question in regards to being able to achieve correct orientation of the handle and tool,or being able to cut a thread to the same position each time.

The brace section of the tool appears to have a spacer on the end of it that joins to the tool.

If that is a spacer then they may of just machined the spacer to suit after the brace and tool were assembled.

Perhaps everything was machined and the brace bent after trial assembly.

I would think that being able to get 2 screw threads to finish at the correct angular alignment 100 yrs ago would of been a little difficult with out some fine tuning of the finished parts.

If the question relates to being able to cut a thread to the same length each time the answer in my opinion would be yes.

[steamboatbrucey]

Well lets just say that screw cutting is about 200 years old give or take a bit Linky Henry Maudslay's original screw-cutting lathe, c 1800. - - Science Museum a very well known innovator in machine tool development Henry Maudslay - Wikipedia, the free encyclopedia can lay claim to the use of a lead screw and gear train Bruce

[Boringgeoff]

Good morning,
Thanks for your response, the question arose from my lack of knowledge and conflicting answers from two friends who I asked.
To answer Pipeclay, after the M and F threads are cut the two halves are screwed together and a pilot hole is drilled for a locking/ locating pin. At this stage, we think, match marks are stamped on each of the two parts so that they can be reunited after other processes have taken place. The wooden handle is a loose fit on its sleeve so that it can rotate when used as a bit brace or wheel brace, which is where the "spacer" or finger wheel is used to get purchase on the handle when putting on or off. The sleeve has a square socket to receive the shank of the crank, which means that the shank can be inserted in four orientations, of which only one would be correct.
Now you could machine the face of the spacer to achieve correct orientation of the crank but this would be another time consuming process which could be avoided by cutting the thread to start at the same position each time?
At the final assembly of the tool, if the crank was slightly off line they could tweak it to line up correctly then into its box and out the door it goes.
They could also quite easily bend each crank to suit the tool but this would then require the crank to be stamped with a match mark and to date no evidence of marks on the crank have been found, and once again a time consuming process.
The link provided by Bruce and the comments by Ewan, Martin and J Ashburn would lead me to think that yes, they did have the machinery and the ability to cut threads the same time after time on a production line.
To try to add some clarity, the attached photo shows the face of the tool with the locking pin at the top and the match mark, 78. The stud at right angles at the back is for connecting the handle when using the tool as a wrench at which time you wouldn't use the crank so handle orientation wouldn't be an issue.
Thanks gentlemen your comments are most appreciated.
Regards,
Geoff.