Why do we still use bobbins?

[AlZilla]

I watched a High-tex video today of basically a longarm quilter, making upholstery panels. It looked to me like they were feeding the bottom thread from a cone at the back of the machine. 

It got me wondering if other industrial machines fed the bottom thread that way. I looked around and don't see any evidence of it.

I could see it being an advantage, not having to mess around with winding bobbins, even on a domestic machine.

 

Look towards the back of the machine at the 2 thread cones. The bottom thread on the workpiece is blue.

"EDIT: So, obviously, this machine is using a standard bobbin setup. The question still remains, why couldn't the hook be fed from a full size spool located away from the bobbin/hook area?"

Edited November 23 by Northmount
Edit added at AlZilla's request

[Constabulary]

maybe it is a chain stitch machine then it does not need a bottom thread.

EDIT:

No - has shuttle hook so it has a bobbin.

http://www.hightex-solution.com/a/Products/machine/Programmable_sewing_m/2021/0218/208.html

Quote

Look towards the back of the machine at the 2 thread cones. The bottom thread on the workpiece is blue.

they wound the bobbin from the blue spool. See the bobbin winder with blue threaded bobbin on the top of the machine? Using 2 spools is quite common in the sewing industries. One for top thread (you can leave machine threaded) and wind the bobbin from the 2nd spool.

Edited November 22 by Constabulary

[AlZilla]

@Constabulary yep, I do see the bobbin winder on top now.

 

But, still ... It seems like feeding the bottom thread from a full spool would make more sense than winding and changing bobbins. Especially in a production environment. 

[Constabulary]

I doubt that it is technically possible. if it was don´t you think someone alreday had invented something in the last 200 years. Well I´m not a technician but in my nut shell I cannot figure how it could work.

When you look at min 3:18 (approx) you will see the hook and bobbin case.

[AlZilla]

I just don't know why the bobbin tension device would care where the bobbin thread itself came from - a little bobbin spool right next to it, or snaking in from a large cone a foot away, at the back of the machine.

[Northmount]

17 minutes ago, AlZilla said:

I just don't know why the bobbin tension device would care where the bobbin thread itself came from - a little bobbin spool right next to it, or snaking in from a large cone a foot away, at the back of the machine.

Just the same as the top thread has to be pulled around the bobbin, it would have to be pulled around the spool.  Huge loop and space required.  How long/high would the take-up lever have to be to pull that loop back up snug?

 

[AlZilla]

18 minutes ago, Northmount said:

Just the same as the top thread has to be pulled around the bobbin, it would have to be pulled around the spool.  Huge loop and space required.  How long/high would the take-up lever have to be to pull that loop back up snug?

 

Isn't the loop all top thread, though? As far as I can tell, the bobbin thread just pays out as needed, no back and forth (or up and down), like the top thread.

"EDIT: So, obviously, this machine is using a standard bobbin setup. The question still remains, why couldn't the hook be fed from a full size spool located away from the bobbin/hook area?"

Edited November 23 by Wizcrafts
AlZilla requested that I add this edit to his last post.

[Northmount]

4 minutes ago, AlZilla said:

Isn't the loop all top thread, though? As far as I can tell, the bobbin thread just pays out as needed, no back and forth (or up and down), like the top thread.

Yes it is all top thread.  Draw it out on a piece of paper showing how it would have to go around a 2# spool and be pulled back up.

 

[AlZilla]

5 minutes ago, Northmount said:

Yes it is all top thread.  Draw it out on a piece of paper showing how it would have to go around a 2# spool and be pulled back up.

 

OK, I'm seeing the flaw in my thinking. It needs to get around the whole spool.

Well, you guys saved me a trip to the patent office, anyway ...  :

[fredk]

If I remember correctly, the very earliest sewing machines used two large spools of thread. The top thread was pulled through the material by the needle and as the needle came up again a loop was made in the thread on the underside of the material. A shuttle, like the shuttle a weaver uses but in miniature, went though the loop pulling the second thread through. At the time this was efficient but prone to timing failures. As the invention of sewing machines progressed the bobbin as we know it was invented and was more efficient, with fewer timing failures. All the inventors adopted the cylindrical bobbin and its circular shuttle. Some fitted it vertical and some had it horizontal and some even had it at an angle, but its the same workings 

[DG1]

Like lots of things, the bobbin size is an engineering compromise. As the bobbin gets larger to hold more thread, the loop of thread that goes around the bobbin case will need to get larger which of course will mean the hook will need to be larger, the takeup arm, etc, essentially the machine would have to be larger/heavier.

There is another consideration also: As stitches are being made, when the needle goes down thread is fed down through the eye of the needle as it goes around the bobbin and then is pulled  back up through the eye of the needle to make the stitch. With a typical sized bobbin case, you can see it's quite a bit of thread, maybe several inches of thread going down and up the eye of the needle, to make one stitch that is say 1/8 of an inch in length. It's kind of hard to picture but basically you have the same segment of thread going through the eye of the needle multiple times. The bigger the bobbin case, the more times the thread will need to go through the eye of the needle, which would probably weaken or fray the thread.

[dikman]

I too pondered this subject some time ago, but then it occurred to me that if it was easy to solve someone smarter than me would have already done it.

[nejcek74]

There are chain stitch machines :))), they don't have the lower thread. As I see it, that is the engineering solution for the problem of uninterrupted stitching.

[AlZilla]

Well, you guys have been kind enough not to beat me up for my brain fart ...

No idea why the part about looping around the entire bobbin escaped me. I've worked on enough of these (and explained the process to rookie sewists) that I knew better.

Feeding the bottom thread from a full spool while keeping some kind of lock stitch will be the next great leap forward.

[dikman]

Yep, whoever comes up with it and patents the idea should make a fortune!

[suzelle]

I have often wished my industrial machines had 2 spools, like these old 2 spool Domestic machines:

eBay item number:116392660262

The add is funny to read. Also interesting. Really geared toward the ladies as most sewing machines were those days.

You can't see it in the advertisement, but the lower spool in the machine would be contained in a "cannister" type case, similar to a bobbin case in our domestic machines. I've seen these machines come up at auctions and listings, but unfortunately they are only domestic or home machines. I agree, if someone could patent the idea, they'd be rich! I believe the patent for the machine in the ad is exempt. So maybe time for somebody to create a patent to produce industrial machines? I'd buy a machine!  I've had lots of thoughts about this too over the years and did find the old patent a few years ago. Very thought provoking.

Edited November 25 by suzelle
sentence diagram

[AlZilla]

1 hour ago, suzelle said:

I have often wished my industrial machines had 2 spools, like these old 2 spool Domestic machines:

eBay item number:116392660262

The add is funny to read. Also interesting. Really geared toward the ladies as most sewing machines were those days.

You can't see it in the advertisement, but the lower spool in the machine would be contained in a "cannister" type case, similar to a bobbin case in our domestic machines. I've seen these machines come up at auctions and listings, but unfortunately they are only domestic or home machines. I agree, if someone could patent the idea, they'd be rich! I believe the patent for the machine in the ad is exempt. So maybe time for somebody to create a patent to produce industrial machines? I'd buy a machine!  I've had lots of thoughts about this too over the years and did find the old patent a few years ago. Very thought provoking.

@suzelle, you pulled me out of the fire!  And now I need to find one of these machines!

Here's a post with a pic: https://www.victoriansweatshop.com/post/show_single_post?pid=1326099274&postcount=9774&forum=501752

A little quick searching and it looks like National made these and may have badged them for other makers, but the search is on.

Thanks for that great lead!

EDIT: Here's a video showing how the bobbin works. She talks about it for about 3 minutes starting at 2:10. 

Close to the end of the video she's sewing with it. The tension arm certainly does have a long swing.

Quite a fun looking machine.

Edited November 25 by AlZilla

[Wizcrafts]

WOW! That bottom spool resembles the bobbins in the 441 and 205 style machines. That ancient National 2 Spool was way ahead of its time. It's like having a Cowboy cb3200, 3500, or 4500 bobbin in a domestic machine using common cotton thread. Amazing!

[Constabulary]

2 Spools, yes but its is still a machine with a hook and "bobbin". But indeed very impressive!

[Wizcrafts]

8 hours ago, Constabulary said:

2 Spools, yes but its is still a machine with a hook and "bobbin". But indeed very impressive!

Yes, it still has a bobbin. But, when this machine came out, its bobbin was actually on one of the tiny spools they used to sell to home sewers. I have some of those wooden spools. People could stock up on the colors they needed on the bottom and sew for a long time before they had to swap spools. I can sew a long time on my cb4500 (441 clone), but rarely with thin thread like the home machines use. I'm not advocating for a new 2 spool machine, just comparing it to our current technology.

[AlZilla]

In case anyone is curious, here's the patent.

 

US1009749.pdf

[Cumberland Highpower]

I'm sure you could design a stitcher to simply accept a 1lb spool as a bobbin.  Therefore, no bobbin required! lol

The challenge would be speed of operation though. With so much thread moving through space and time, looping around the massive shuttle, you probably would have a pretty low SPM, defeating the whole idea. Would require lubed thread for sure, but could be done.  I hate winding bobbins.......

There's a bit of a trend that's phasing out sewing as an operation in manufacturing, outside of clothing.  Molded parts, ultrasonic welding, adhesives, etc.  Your 2024 Chrysler might have a good deal of stitching in the interior, but I'm guessing your 2054 Geely SUV won't?

Probably not enough future demand for new sewing technology I think?

Just some thoughts.

 

 

Edited Wednesday at 11:52 PM by Cumberland Highpower

[Wizcrafts]

The main advantage of a lockstitch sewing machine is the stitches resemble each other on the top and bottom. As leather sewers, we are accustomed to a different result on the bottom and sometimes fight to hide the lockstitch knots from both sides. This stitch is very strong and can hold together somewhat if some of the stitches get cut, or simply break under stress. Off course. a lockstitch machines stops forming stitches the moment it runs out of bobbin thread.

The answer to this is the chainstitch machine. It only has a top thread. There is a looper mechanism on the bottom, under the needle plate, which forms a loop around the thread on the bottom. The top will almost always look perfect, unless the tension is way too tight. The stitches are as strong as the thread rating. But, if one stitch breaks, the entire chain could unravel.

In the days of yore, hard shell rifle cases, some boots and luggage were sewn on chainstitch machines. The loops were hidden behind material glued to the inside of the cases, or the insole on the boot. In many instances, the machine had a top mounted wax pot containing heated beeswax that the thread ran through. The hot wax hardened after a minute or so and those stitches could last a century. From the late 1800s through the mid-1900s, Puritan was the premier brand of needle and awl chainstitch machines. Some are still in use in the RedWing factory, making work boots using two or three needle chainstitch machines. But, now they usually run dry, bonded polyester thread.