Brake Operating Apparatus and Brake System by Shimano

In this article, we’ll be discussing a Brake Operating Apparatus and Brake System by Shimano, US patent 11,007,987. The filing date is May 20th, 2019 and the publication date is May 18th, 2021. This one is granted as novel.

First, wtf is up with this fork…

Second, I’m may or may not be putting some subtle discrepancies in these articles, so when others publish an article about the same document, I might be able to catch someone just changing my words instead of actually reading the patent. Good luck.

Brief Summary (tl;dr)

This document shows very clearly that Shimano are working on electronic brakes. In this case, it’ll be for a road bike, but the design can be used for a mountain bike, commuter, etc. Ultimately, Shimano have developed a new electronic braking system that utilizes hydraulic braking with electronic actuation, not mechanical braking like other systems. They’re doing this using a lever position detector, a controller, an electrical actuator, and a conversion mechanism. In short, the system will detect a lever position, the controller will calculate the lever position information and output instructions to the actuator. The actuator then applies a rotational force to a conversion mechanism, which applies brake fluid pressure to a caliper.

Background

In cars, brake-by-wire systems have been around for a long time. It’s the obvious next step for consistency and performance. Want to add more braking power? Just increase voltages, currents, actuator size, among other things. It appears as though Shimano are developing the same thing for a bike, but the idea isn’t new (proof). Though I’ve never actually seen it in real life.

Brake by wire is used in nearly every new car being produced. I know I bring up cars a lot on this website, but the reality is that the automotive industry is the most advanced industry on earth, with respect to technological breakthrough and manufacturing might. They can make literally anything, whenever they want.

Funny story, when I was building Gulfstream jets in 2014, we were just introducing Bluetooth into our planes. Could you imagine buying a $65m plane without Bluetooth in 2014? It had been in cars for 10+ years before that (Chrysler). Right now, the bike industry is following the automotive industry from 20+ years ago.

Intended Novelty

I believe the explicit novelty here is the controller and actuator are both located inside the ‘support’. The support is the actual handlebar. This is a legalese novelty and is not as important as the entire idea of an electric braking system.

Why

Overall, the entire bike industry is going electric. It gives the designers a very high level of freedom, reduces weight, and makes the bikes easier to use. In this case, rather than the current kinematic and mechanical solution dictating braking performance, a simple detector/controller/actuator system can perform the same task (maybe) at a higher level. Overall, it’s a simpler design and, if good components are used, could be more reliable and robust. Again, look at the automotive industry. They typically don’t make bad decisions. 

The user should have more freedom to adjust the brakes to their liking, such as bite-point adjustments. Additionally, with the use of electric brakes, sensors and algorithms can be used to control the brakes (i.e., ABS) for a safer ride.

In the end, I think they’re doing this because they have to. If they don’t, someone else will.

What

FIG. 2 shows a simplified diagram of the system. First, the detector detects a force applied to the lever using a strain gauge (piezoelectric, magnetostrictive, etc.). or can detect a displacement (Hall element and a magnetic reed of a reed switch) or relative movement from zero that the lever has traveled.

The detector 40g can detect a force applied to the operating member 40c. The detector 40g includes a strain sensor that is arranged to detect a force applied to the operating member 40c.

The interesting part here at the detector can calculate accelerations, which can assist in hyper-performing actuators, similar to the Live-Valve system (which uses jolt – 1st derivative of acceleration) to send signals to the damper adjustment.

…the detector 40g is configured to detects a displacement of the operating member 40c from the rest position to the operated position. The displacement of the operating member 40c includes a rotational angle, a rotational speed, and a rotational acceleration of the operating member 40c.

Then, we have a controller. It’s just like any other controller. It’s got a memory and processor and takes the detected information, runs the information through a magic algorithm, and outputs instructions to the actuator. Nothing special here.

The actuator is what drives the brake caliper. In short, it’s an electric motor attached to a screw.

Component 40i is the actuator, which applies a rotational motion using threaded shaft 42a to a ball screw 42 (threaded nut), which moves the piston in and out. In essence, this is a screw-type linear actuator. The piston then moves hydraulic fluid through the tubing 50 and you have braking, just like normal bike.

The conversion mechanism converts the power from the actuator into a driving force for the brake caliper. In short, the conversion mechanism converts rotational motion into linear motion, which then creates hydraulic pressure to the caliper. Now, FIG. 3 shows much more detail of the conversion mechanism.

Conclusion

The ramifications of this only have an impact on one person right now, Mr. Dangerholm. This is your answer. This would only require a very small hole in the bars, rather than the big ass hole needed for a hydraulic line. In fact, I’d bet any amount of money that we’ll see a wireless system soon, which would be very easy to do. All they’ll need to do is include a wireless controller and a wireless receiver at the actuator. In reality, I’m sure it would be much more difficult to, but that’s the high-level answer.

I think I’d use this. I really don’t see an issue with it. I know people will talk about ‘battery this and that’, but they’ll have a failsafe like a light or alarm. As always, I’m impressed with Shimano’s ingenuity and innovation. Whether you like the progression of the bike industry or not, they’re really moving this sport in a… direction.

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