How The Carbon Electric Motor Brush Came into Use

[Russ Huber]

You will witness two names stand prominent originating in the 1880s to bring the eventual broad use of the carbon electric motor brush. These men are George Forbes and Charles J. Van Depoele. 

 In 1882, Forbes became manager of the British Electric Light Company, manufacturers of carbon filaments and arc lamps. He experimented with using carbon for the brushes in electric motors, rather than wire or gauze and in 1885 took out a patent for the Improved Means for Establishing Electric Connection between Surfaces in Relative Motion Applicable to the Collectors of Dynamo Machines. This advocated carbon as a current collector for rotating electrical machines. The invention would prove outstandingly successful and it is in universal use in electricity generation to this day. He could have become a rich man with such an innovation but he sold his American patent rights to Westinghouse Electric for £2,000. There is no evidence that he received any UK royalties. In the obituary published in the Proceedings of the Philosophical Society, G. L. Addenbroke wrote that 'Forbes always referred to this work with much modesty, but there can be no doubt that, he presented to the World an idea of great engineering and commercial value, the importance of which he does not seem to have fully grasped at the time.

 

The First Application of the Carbon Brush. The first commercial application of the carbon brush occurred in 1888. The story is best told by Elihu Thomson: “It is, I think, true that no single thing has had a greater or more direct influence, upon the technical success of railway machinery than the introduction of the carbon brush as a substitute for the various forms of metal brush, many forms of which had been tried previously on railway motor commutators but without even the beginning of success. Simple as this substitution was, the results are of the greatest importance. The pioneers in electric railway work had been struggling with the many problems presented, not the least of which was to get a motor Commutator to run under varying loads without spark, to run in either direction without trouble, and without need of changing the lead, and above all to endure for a reasonable time.

“All forms of metal brush had been tried and become acknowledged failures. They were only calculated, under the harsh conditions, to be ground and to grind the commutator, into dust at a rapid rate (such dust being scattered by the pound along the line of way), with the production, at the same time, of a flickering greenish illumination under the car, an illumination all the more ghastly on account of the havoc known to be going on and of which it was an unfailing index. It is not too much to say that before the carbon brush was substituted there was in prospect inevitable failure; disaster not unforeseen, but all to evident.

“But how did it come about? I do not know that the circumstances have ever been detailed in print, and it shall be my present purpose to fill this gap in the history of electric railways and, at the same time, to pay tribute to the memory of Mr. Chas. J. Van Depoele, truly a pioneer in this art and to whom was due the suggestion of the use of carbon as a brush for railway motors.

“It came about in this way. We had been trying to use on the first roads installed by the Thomson-Houston Co. (Author’s note: now GE) in 1888, various forms of copper and other metal brushes, all of which, however, had soon been condemned as either quite worthless for the purpose of so nearly worthless as practically to be so. A discussion of the matter between Mr. Van Depoele and myself, attended as it was by many expressions of misgivings as to the fate of the electric railway work unless a radical change for the better could soon be made in the commutators, led him to remark in substance: “I have used a plate of carbon as a brush on a stationary motor which carbon brush worked well, and I think it might answer the purpose here.”

“The trial was made and was at once so eminently successful that scarcely any time elapsed before the metal brush became a thing of the past, not only on the Thomson-Houston railway motor apparatus, but on others also as soon as the news got abroad. We called the new brushes “carbon brushes,” though of course they have very little of the brush proper about them.

“I remember inspecting one of the first carbon brushes applied in railway work to a motor commutator after it had had a reputed run of 5,000 miles. It had only worn down to a moderate extent and the commutator retained its smooth black polish. Then it was that we knew that the difficulty, at one time so serious and exasperating, had been removed and our reputations as skilful electrical engineers saved for the time.”

Thomson continues: “The first proposal to use carbon as a current collecting brush for dynamos was made by Prof. George Forbes, in a British patent of 1883”

George Forbes (scientist) - Wikipedia

The Observatory, Pitlochry, Perthshire, Scotland (observatorypitlochry.com)

Electrical Engineer - Google Books

1498386030377955329-00390921 (storage.googleapis.com)

1499074381620437801-00422265 (storage.googleapis.com)

 

Edited September 26, 2024 by Russ Huber

[Russ Huber]

“But how did it come about? I do not know that the circumstances have ever been detailed in print, and it shall be my present purpose to fill this gap in the history of electric railways and, at the same time, to pay tribute to the memory of Mr. Chas. J. Van Depoele, truly a pioneer in this art and to whom was due the suggestion of the use of carbon as a brush for railway motors.

 

Robert Lundell used carbon pencil brushes in his 92 introduction IC fan motors.  It appears the issues and stresses placed on the larger electric brushed DC railway motors brought the use and benefits of carbon motor brushes into the light. 🙂 

 

[Nicholas Denney]

This is an interesting topic to me, to be sure. I have a dynamo that for all intents and purposes appears to have been made by a company that was liquidated by court order in 1886, thereby demanding it date to that year at the very latest. It however, has carbon block brushes on a curious open 'sled' type of arrangement and I've debated their originality since this piece was found wired with spark suppression capacitors.Yes, it is a very rare motor. No, no one else owns one; it took me over a year just to get an ID that I felt somewhat comfortable with. But, the McTighe Electric Light & Manufacturing Company was an innovative and patent-holding company, however poorly managed it was; from 1881 to 1886 and a restructuring in-between, that's a pitiful run for even an early company in this industry.

 

 

 

Edited September 27, 2024 by Nicholas Denney
Revision for content and clarity

[Russ Huber]

6 minutes ago, Nicholas Denney said:

It however, has carbon block brushes on a curious open 'sled' type of arrangement and I've debated their originality since this piece was found wired with spark suppression capacitors which clearly post-dated it.

Then what does your post have to do with being on this post?

[Nicholas Denney]

3 minutes ago, Russ Huber said:

Then what does your post have to do with being on this post?

This post is titled "How The Carbon Electric Motor Brush Came Into Use".

A quote from material you've posted is as follows;

" The First Application of the Carbon Brush. The first commercial application of the carbon brush occurred in 1888 "

I posted my motor with carbon block brushes because, to the best of my knowledge, it predates 1888. I'm sorry if you aren't looking for your information to be debated or challenged.

[Russ Huber]

Let's see the embossed name on your example, please. Or at least some form of manufacturer identification on the motor.

[Nicholas Denney]

The machine is completely bare of identification or evidence of ever having such affixed, otherwise I would not have had to put in any work seeking it. I first attempted to find any known machine at all that even vaguely resembled it, wholly or partially. I consulted with every dynamo and motor collector including Petra Vavra and others outside the US. 

I have, on my own, found what I view as damning evidence of its maker. Please review it carefully, in detail. Thank you...

The first image depicts a silhouette and attributes it very specifically; this silhouette is practically a shadow of my own machine. 

The second through fourth images focus on the very specific design of the interface between the armature windings and the commutator segments. 

The remaining images depict and describe the exact construction of my armature as I am able to observe personally.

Edited September 27, 2024 by Nicholas Denney

[Russ Huber]

54 minutes ago, Nicholas Denney said:

The machine is completely bare of identification.

 I have, on my own, found what I view as damning evidence of its maker. 

The woodcut clearly shows a cast embossed manufacturer name on the motor frame. That would be characteristic of them to maintain, FWIW.

You have pointed out they were a short-lived concern. What stops another manufacturer from using their frame design later down the road? Your motor frame design and pole placement are similar but does not match the McTighe woodcut frame.

Your motor brush carriage doesn't even come close to the unique McTighe brush carriage design. 

Most importantly, by your own admission in quotations below you clearly state you question the validity of the carbon brushes wired with spark suppression capacitors on your own example. The machine has no identification on it. "You" alone have connected it to the McTighe concern (Your quote above). 

"It however, has carbon block brushes on a curious open 'sled' type of arrangement and I've debated their originality since this piece was found wired with spark suppression capacitors which clearly post-dated it."

 

 

Edited September 27, 2024 by Russ Huber

[Nicholas Denney]

2 minutes ago, Russ Huber said:

The woodcut clearly shows a cast embossed manufacturer name on the motor frame. That would be characteristic of them to maintain, FWIW.

You have pointed out they were a short-lived concern. What stops another manufacturer from using their frame design later down the road? Your motor frame design and pole placement are similar but does not match the McTigue woodcut frame.

Your motor brush carriage doesn't even come close to the unique McTigue brush carriage design. 

Most importantly, by your own admission in quotations below you clearly state you question the validity of the carbon brushes wired with spark suppression capacitors on your own example. The machine has no identification on it. "You" alone have connected it to the McTigue concern (Your quote above). 

Would they have their name cast into every one of their machines? That's an assumption.

What stops another manufacturer from copying them down the road? Patents, and extensive, well-publicized writeups of their designs. They sold off their assets, not their patents, and I don't think there was very much interest in such a primitive design very far down the road. At any rate, what right-minded outfit would want to copy the designs of a very short-lived company that went to debtor's court? 

I assume you refuse to accept its identity based on how early it would date the machine. I wouldn't bother with that as this is hardly the earliest of electrical artifacts in my collection. 

Let me ask you this instead; what other machine silhouette would you suggest it more closely resembles in the first image? And... what other commutator design MORE closely matches? If you have nothing to offer, I would say your rebuttal is lacking in real substance. 

[Nicholas Denney]

Just a sanity check, for myself....

[Russ Huber]

44 minutes ago, Nicholas Denney said:

Let me ask you this instead; what other machine silhouette would you suggest it more closely resembles in the first image? And... what other commutator design MORE closely matches? If you have nothing to offer, I would say your rebuttal is lacking in real substance. 

 

This was just recent posting. Depoele's motor frame concept was patented in 88. It appears Edison, Mason, and Kent had no problem running with it down the road. 

[Nicholas Denney]

Yes, I commented on the striking similarity of that fan to the Edison fan, even down to the homage of the three-legged tentacle-like base.

However, this doesn't have anything in my machine or the machine I'm comparing it to. As I said before, I've searched quite exhaustively for identification and this is a 9/10 to me while everything else I've looked at seemed as alike as monkey wrenches and monkey bars.

[Russ Huber]

Check out the SCREWS used in the McTighe armature windings to commutator segment connections seen in their patents and their woodcut image. Now compare that to your example. Just another important detail missing on your motor. But that won't matter because no matter what I post YOU are going to be incurably justified in your defense of your 'claimed' McTighe motor. 🙂

[Russ Huber]

McTighe generator. It has similarities to the motor woodcut construction, not to your motor. And most importantly, no carbon brushes. 

Edited September 27, 2024 by Russ Huber

[Nicholas Denney]

14 minutes ago, Russ Huber said:

Check out the SCREWS used in the McTighe armature windings to commutator segment connections seen in their patents and their woodcut image. Now compare that to your example. Just another important detail missing on your motor. But that won't matter because no matter what I post YOU are going to be incurably justified in your defense of your 'claimed' McTighe motor. 🙂

 

 

 

The problem is you're obsessing over miniscule differences while I am looking at overall design. I have not come across any other dynamo that even has rod-like elements connecting its coils to its commutator. None! I'm asking you; where, and what, are these other comparators?

This debate is you arguing that the number 895 isn't 899, while I'm telling you that those numbers are fantastically close to one another compared to 50, 275, 416, 780, and 2149. I'm not even sure why you're taking this approach, since there are more significant differences between consecutive years of GE pancakes than a bunch of fiddly screws. 

Edited September 27, 2024 by Nicholas Denney

[Russ Huber]

Dynamo-electric Machinery - Google Books

[Russ Huber]

 

Edited September 27, 2024 by Russ Huber

[Russ Huber]

3 hours ago, Russ Huber said:

Dynamo-electric Machinery - Google Books

You can add Elwell & Parker to the list of potential manufacturers of your unidentified motor. 

[Nicholas Denney]

7 hours ago, Russ Huber said:

You can add Elwell & Parker to the list of potential manufacturers of your unidentified motor. 

I can? American to British machine is a big jump, and their general style is nothing like McTighe that I can find. It is simply being lumped in with the Manchester style, of which American machines are typically not made. And of course, the Joel image you have placed there, that is a Pacinotti armature machine rather than Gramme. Radically different! But I'm a visual guy too, so, like I have stressed to a fault, show me images of dynamos that aren't McTighe, that at least look as visually similar as my machine. The burden of proof is on you!  Don't argue me, dazzle me with evidence.... please.

[Russ Huber]

12 hours ago, Nicholas Denney said:

The burden of proof is on you!  Don't argue me, dazzle me with evidence.... please.

Possession is 9/10s of the law. The burden is yours. Your motor has NO identification. You can blow steam about this and about that until hell freezes over and nothing is going to change the fact it has... NO identification.  I have given you proof that the motor frame is not exclusive to the McTighe concern, a point you were standing strong on.  I have pointed out things about patented McTighe motor/dynamo construction that don't follow your motor construction. There is a reasonable element of doubt.

You know how to do research. You own the motor. Let us know when you can find the damning evidence beyond a reasonable doubt you own a McTighe motor. Have at it in the books and when you hit gold, let us know. 🙂

 

Edited September 28, 2024 by Russ Huber

[Russ Huber]

On 9/27/2024 at 12:28 AM, Nicholas Denney said:

The machine is completely bare of identification or evidence of ever having such affixed, otherwise I would not have had to put in any work seeking it. I first attempted to find any known machine at all that even vaguely resembled it, wholly or partially. I consulted with every dynamo and motor collector including Petra Vavra and others outside the US. 

I have, on my own, found what I view as damning evidence of its maker. Please review it carefully, in detail. Thank you...

The first image depicts a silhouette and attributes it very specifically; this silhouette is practically a shadow of my own machine. 

The second through fourth images focus on the very specific design of the interface between the armature windings and the commutator segments. 

The remaining images depict and describe the exact construction of my armature as I am able to observe personally.

 

I forgot sharing this image I dug up days ago on your quest to Identify your unidentified motor. As you can see the method of armature winding connections to the commutator are not exclusive to the McTighe motor. And it 'appears' screws are not used in the winding to commutator connections on this motor as seen on the McTighe motor.

It gets interesting, doesn't it? Lots of curve balls. Good luck on identifying your motor.

[Nicholas Denney]

1 hour ago, Russ Huber said:

As you can see the method of armature winding connections to the commutator are not exclusive to the McTighe motor. And it 'appears' screws are not used in the winding to commutator connections on this motor as seen on the McTighe motor.

 

That maker, like a few others, uses flat strips rather than any type of rod, and there are a few other key details missing in the construction.

But let me steer you back on the right path. You've suggested exclusively European makes to me, which is not possible, unless you are suggesting that a company in Europe would be building on US Imperial system rather than metric. Let's not lose the forest for the trees! 

[Russ Huber]

On 9/27/2024 at 12:28 AM, Nicholas Denney said:

The machine is completely bare of identification or evidence of ever having such affixed, otherwise I would not have had to put in any work seeking it. I first attempted to find any known machine at all that even vaguely resembled it, wholly or partially. I consulted with every dynamo and motor collector including Petra Vavra and others outside the US. 

I have, on my own, found what I view as damning evidence of its maker. Please review it carefully, in detail. Thank you...

The first image depicts a silhouette and attributes it very specifically; this silhouette is practically a shadow of my own machine. 

The second through fourth images focus on the very specific design of the interface between the armature windings and the commutator segments. 

The remaining images depict and describe the exact construction of my armature as I am able to observe personally.

 

[Russ Huber]

On 9/27/2024 at 2:42 AM, Nicholas Denney said:

The problem is you're obsessing over miniscule differences

The McTighe boys liked using screws to connect their armature windings to the commutator. That is not a miniscule observation. That is a fact, Jack.  They have a classy brush rocker as well. Notice how their fields are bolted in both dynamo and motor. Good luck identifying your motor.

1498389615044905966-00288830 (storage.googleapis.com)

 

 

 

 

 

 

 

 

Edited September 29, 2024 by Russ Huber

[Andrew Stancioff]

Interesting bit of information on the Carbon Brush. 

My Grandmother had always told me that her father James Cameron Mitchell had invented the Carbon Brush. 

I recently discovered an autobiography (Sept 1920) of my great grandfather, James Cameron Mitchell, electrical engineer and founder of the Alabama Power Company and numerous other enterprises, in which he describes working with Charles Vandepoele. 

Mr Vandeppoele was having trouble with the tangential type of copper leaf brushes which he used on his motors at the time. He asked James Cameron Mitchell what he thought of using carbon brushes. Whereupon he said it probably wouldn't work since carbon would create too much resistance. Mr Vandepoele responded with, "Carbon would not be too high a resistance for a 500 volt trolly current, but that it would be for the low voltage between the commutator segments" So my grandpa Mitchell went to a local electrical supply house and purchased a block of carbon and with a hacksaw he sawed out a set of brushes for Mr. Vandepoele motor.  "We applied them and,  to our great satisfaction and no less amazement, the commutation ran sparkless under every condition."

He goes on to describe how well they worked and how he went on to install carbon brushes for Thomson-Houston equipment and all worked to satisfaction. 

He went on to make carbon brushes for many other cities electric railways and companies, and went on to convince them that the Carbon Brush was the way to go. 

Anyway, I just thought I'd chime in and wondering if you'd come across his name in any of your research. 

Thanks Andrew Stancioff