This article focuses on the parts and mechanisms used to operate a watch (collectively referred to here as the operating system), focusing on push-button operating systems. There are many variations in the functions that can be assigned to push-button operating systems, and we will explore the perspectives that led to the selection of these types.
Text by Shinichi Sato
Article published on June 2021, 12
Operating a watch requires some kind of operation. In the previous article, we focused on the crown, which is closely related to winding the mainspring and displaying the time. As a result, we learned that multiple functions have been integrated into a single crown, and improvements have been made to its shape and placement depending on the purpose.
What about adding more functions or functions that are operated frequently? Since using only the crown makes operation complicated and has mechanical limitations, push-button type controls are often added.
Examples of functions that are often assigned to push buttons include operating the chronograph, adjusting the moon phase, and adjusting the perpetual calendar. The chronograph is a function that is likely to be used multiple times in a short period of time, such as measuring lap times. In contrast, once the moon phase and perpetual calendar are adjusted to the correct display, they do not require operation for long periods of time. Therefore, there is a large difference in the expected frequency of operation, and it will be interesting to see how this difference relates to the operating system.
On the other hand, digital watches such as G-SHOCK use switches with electrical contacts, allowing for both the frequently operated stopwatch and the less frequently operated time and date adjustments with a single switch. What is the reason for this difference? In this article, we will take a closer look at the controls from this perspective and also consider the smartwatch that currently offers the most versatile operation.
The classic placement of the "chronograph," a watch with buttons
When it comes to watch controls, the next thing that comes to mind after the crown is the chronograph pusher. Many models equipped with a chronograph have the start/stop function at 2 o'clock, the reset function at 4 o'clock, and the crown at 3 o'clock. One of the most famous models is the Omega Speedmaster.
Manual winding (Cal. 3861). 26 jewels. 21,600 vph. Power reserve approximately 50 hours. Stainless steel (diameter 42mm, thickness 13.18mm). Water resistant to 5 bar. Price: 847,000 yen (tax included).
To operate the start/stop pusher at the 2 o'clock position, press your thumb around the 8 o'clock position and operate it by pinching the head. The advantage of this is that the pushers with different functions are located around the crown, making it easy to distinguish them even by feel. Furthermore, the lugs and bracelet do not get in the way when operating the watch, making it easy to operate.
This layout is the current standard for chronographs. However, I think the reason why many manufacturers currently use this layout is not because of any clear intention, but rather because it has been used many times historically and many people are familiar with it, there is a wealth of design know-how for this layout, and there are no major disadvantages, so there is little need to go to the trouble of changing it.
A chronograph with controls at 12 o'clock, as seen in the 1970s
Just as everything changes and goes through trends, there are trends in operating systems that change with the times. In the 1970s, there were several chronograph models that had the crown at 12 o'clock and pushers at 11 and 1 o'clock. This arrangement was often achieved by rotating the movement, which was based on the Speedmaster arrangement, by 90 degrees, making it easy to use existing movements such as the ETA7750.
Examples of watches that use this arrangement include Citizen's "Chronograph Challenge Timer," commonly known as the "Tsuno Chrono," and Sinn's "Bullhead Chronograph," both of which were reissued in 2021.
This is a revival of the model released in 1973. Upon its re-release, the nickname "Horned Crocodile" became its official name. Quartz movement (±20 seconds per month). Stainless steel case (38mm diameter, 11.7mm thick). Water resistant to 5 bar. Each is priced at 26,400 yen (tax included).
To prevent the crown and pushers from interfering with the bracelet, Citizen's Tsuno Chrono has a structure that connects the bracelet to the bottom of the case, while Sinn's R500 is characterized by a thick case and an inclined dial, i.e., movement, that stands up at 12 o'clock.
Let's consider the intention and benefits of this "bullhead" arrangement. The Sinn R500 was based on the theme of motorsports. At the time, power steering was not commonplace and tires had poor performance, so if you tried to drive it in a sporty manner, the steering wheel would have been quite violent. This meant that there would have been no time to operate the chronograph gracefully, and it would have been impossible to take one hand off the steering wheel.
Automatic winding (Cal. ETA7750). 25 jewels. 28,800 vph. Power reserve approximately 46 hours. Ti (diameter 42mm, thickness at 12 o'clock 16mm, thickness at 6 o'clock 13mm). Water resistant to 20 bar. Limited to 300 pieces. 770,000 yen (tax included).
In this case, if the pushers are located at 1-11 o'clock, and the wrist of the left hand gripping the steering wheel is supported by the palm of the right hand, the index and ring fingers of the right hand will naturally rest on the pushers. In this case, the watch can be supported with the flat surface of the palm, as in martial arts, providing stability. This arrangement can be considered to make it easier to operate the chronograph without interfering with driving, and although it is a minor feature, I believe it is a rational arrangement considering its intended use.
