The history of the clutch is a convoluted one, if only because there was no single clutch design. There were several iterations over the years and the original clutch and associated transmission system could be fixed by just about anyone, due to their simplicity.
Most of the credit for the invention of the clutch goes to Karl Benz, who also designed and patented the world’s first internal combustion-driven automobile in 1885. However, Charles Borg and Marshall Beck are credited with the invention of the sliding clutch, while Professor Henry Selby Hele-Shaw gets that prize for inventing the friction clutch.
There is a lot of love to go around when it comes to inventors of the clutch, which has evolved over the years into a single part of an enormously complex transmission system. If you just had to narrow the invention of the clutch down to a single person in history, it would have to be Karl Benz.
The Original Clutch
Karl Benz was a German mechanical engineer and, of course, his last name is now recognizable across teh entire planet. It would honestly be surprising if one of those lost tribes in the Amazon didn’t know who Karl Benz was.
Karl Benz’s first car wasn’t what you would think of when you envision some of the earliest cars. His first patent was for a three-wheeled monstrosity on extremely wide-rimmed bicycle tires. Of course, back in the day, it must have seemed like a loud, magical device from another world.
Karl’s clutch initially went into these first forays into combustion-propelled machinery but there was a problem. The clutch would burn out rather quickly as the threads in the clutch covers were so precise and tiny that they wore out fast.
This would result in slippage and the need for a replacement in a short amount of time. Fortunately, replacing a clutch was something that a chauffeur could do and it was relatively inexpensive, as was Karl’s first assembly line of 1,200 vehicles.
Not enough credit is given to his wife, Bertha Ringer, whom Karl married in 1872. His wife was basically a roadside mechanic, fixing Karl’s first cars on the fly and she led the way in identifying and eliminating problematic designs and implementations.
Eventually, however, the original clutch that Karl Benz designed, while brilliant in its own right, was not enough and it had to be improved.
The Sliding Clutch
This is where Charles Borg and Marshall Beck come in as they invented the solution to the original clutch slipping issues. The sliding clutch was one that could be operated by hand and contained 32 male threads on the inner casting.
Fitted with shafts and attached to the pulley, a fork was then mounted to the contraption that ended in a hand lever for the purpose of engaging the clutch at certain points of acceleration.
The original, of course, was a prototype, all held together by glue, lathes, vice grips, and a lot of hope and prayers. Eventually, the product made it to the showroom floor and became the new clutch through which everything else revolved.
The two inventor’s initial production line went to the military, as they were looking for a more reliable clutch system for their four-wheel drive trucks. The clutches that Charles Borg and Marshall Beck invented and mass produced were an astounding success, lasting for well over two years before they died and required a replacement.
The Hele-Shaw clutch is a multi-plate clutch and arrived after the sliding clutch in 1905. Professor Henry Selby Hele-Shaw was the inventor and this type of clutch was used in both the automobile and marine functions. In fact, this clutch was used for extremely high-powered propulsion systems.
Unlike the sliding clutch, the Hele-Shaw clutch was highly resistant to overheating and the typical wear and tear that vehicles placed on clutches at that time period. The Hele-Shaw clutch is designed to operate wet, which means that it constantly requires oil for lubrication during operation.
The Hele-Shaw clutch was also a clutch that contained multiple plates and, unlike all of the previous clutches, the Hele-Shaw clutch did not use friction. It was a first-of-its-kind clutch system that relied on fluids and pressures, which was fitting coming from a man who was renowned for his understanding of viscosity.
On the outside, no one except for those with keen eyes and an understanding of clutch systems could differentiate between the Hele-Shaw Clutch and other clutches in the same period.
If you looked closely, however, beneath the outer cover, you would see that there is more than one plate, each one crafted of thin sheets of steel. The fluid between the clutch, when engaged, created enough pressure to shift the gear, without using friction.
Since this new design relied on the properties of viscosity and pressure, rather than friction, the level of heat that they generated was far less than that of previous friction clutch iterations and it placed the clutch in a position that is much closer to today’s clutches.
Technological Development of the Clutch
While we have demonstrated that Karl Benz is credited with the invention of the clutch, the four people that invented the above-listed clutches are really the fathers of clutch innovations that still resonate today.
Technological innovations in the clutch haven’t changed all that much from Hele-Shaw’s version, but there are certainly more complex in their functionality and integration with automatic transmission systems of today.
Both wet and dry clutches are still used today and though the technology, mostly in terms of materials, has improved since the first decade of the 20th century, the concepts originated by Benz, Borg, Beck, and Hele-Shaw remain the same.
Although Karl Benz invented the clutch as we understand it today, there were many more who contributed to the evolution of the clutch and there are more mechanical engineers out there today that are still evolving the clutch today.
Karl Benz was a phenomenal inventor and although many of us can’t afford to drive a Mercedes Benz, we can enjoy the fact that all of our vehicles share a commonality with the original mind that gave us the clutch.