A CLOSER ‘TECHNICAL’ LOOK AT SEIKO’S SPRING DRIVE TIMEPIECES

A CLOSER ‘TECHNICAL’ LOOK
AT SEIKO’S SPRING DRIVE TIMEPIECES


by Jack Freedman
© 6-20-2005

INTRODUCTION

On one of the internet watch discussion forums, back in 1998, I wrote and shared my thoughts about the THE RE-EMERGING POWER OF SEIKO TIME. I covered some historical links of the company in general and how I came to follow closely many significant developments. I realized back then that this company was no sleeping giant.

Today, more so, I cannot hide my affinity for Seiko as a leader of watchmaking innovations especially since their introduction of their ‘Spring Drive’ timepieces.

First, a brief definition of Seiko’s ‘Kinetic’ -- the predecessor to their ‘Spring Drive’.

Kinetic

Kinetic is Seiko’s name for a category of watches that differ from standard quartz watches in that they never need a battery change. That’s because a Kinetic watch generates its own electrical power.

Seiko Kinetic is the first quartz watch powered by human movement which uses the simple motion of the wearer’s arm to create electricity to run the watch, a development so significant it led to the application for more than 50 patents. The process uses an oscillating weight that is rotated by the movement of the wrist: this movement is transformed into a magnetic charge, then into electricity, which is stored in a tiny capacitor or a rechargeable battery for up to six months. It never needs a battery change.

How it works

Every movement of the oscillating weight in the kinetic watch is turned in to a magnetic charge. The rotors in kinetic watches can spin 100,000 RPM’s faster then a formula one race car. This is where the magic of kinetic watches begins. Every movement of the oscillating rotor in the kinetic watch is turned in to a magnetic charge. The extremely high density coil in kinetic watches transforms the magnetic charge created by the kinetic watches rotor in to electricity to power the watch. A very vital piece in a kinetic watch is the circuit block. The block controls the voltage, amps, and by quartz oscillation, produces a precise watch signal. The oscillator oscillates at a highly stable rate of 32,768 time per second. The step motor then converts the electrical signal in to a precise rotational motion that is transmitted to the hands through the gear train.

The first generation of these watches had its critics who asserted that the Kinetic is a gimmick, both technologically and from a marketing point of view. It is basically a quartz watch, whose timekeeping mechanism is identical to any present-day quartz watch. Its only innovation is the fact that it replaces the aspirin-sized (or smaller) battery with a much more bulky generating system and a very high grade capacitor for energy storage.

Now, let’s have a quick overview of Seiko’s next development in timepieces – the first Spring Drive timepieces.

Spring Drive Kinetic – Manual Wind

The most important development in Kinetic technology since Kinetic was introduced in 1994, is the watch with a new kind of movement called the Seiko Spring Drive Kinetic. It combined mechanical watch technology with Kinetic technology. As in a mechanical watch, the energy to drive the watch comes from the uncoiling of a wound spring. The energy is converted into electricity used to keep the watch running with the quartz accuracy of + or - 15 seconds per MONTH. A fine-tuned IC control ensures smooth sweep second-hand movement just like a mechanical watch and unlike typical quartz watches whose sweep second hands pulse in per second increments. In addition, when the spring is fully wound, the watch keeps running for two to three days like a conventional mechanical watch.

Most remarkable, something not mentioned by Seiko and which escaped the press, is the fact that, for the first time in history, Seiko introduced a movement - their new Kinetic Spring Drive - with an exquisite Swiss-style finish perhaps deserving the "Geneva Seal" or an equivalent prize. At the Basel Fair '98, I had the pleasure of viewing the one prototype in a lighted glass display reflecting its hand finished, highly polished, and embellished "guilloch" train bridges. The timeless elegance of this movement struck and left me with a memorable impression of just how far the Japanese have caught up with Swiss standards simultaneously surpassing it with advanced technology.



[ Photograph of Spring Drive Kinetic Parts ]

Seiko’s ‘Spring Drive Kinetic’ is a product created from high tech bionics. It combines the world’s leading Kinetic technology with a spring-driven mechanism to offer quartz accuracy with the traditional appeal of a mechanical watch sweep second hand, and the convenience of no battery.

This timepiece revolution has been made possible by two stunning breakthroughs in Seiko’s technical research development. One is the ultra-energy efficient IC (integrated circuit), the world’s first to be incorporated successfully in a wrist watch. The other is the ultra-high performance, electrical generator, which has emerged from Seiko‘s unique expertise in Kinetic technology.

The integrated circuit runs on only 0.5 V, half the voltage of a conventional low-energy chip, and it consumes only one third of the electrical energy needed by previous ICs.

The driven momentum of the Spring Drive Kinetic come from the spring uncoiling. It turns a series of wheels with a rotor in the final wheel. The turning of the rotor with a fixed coil block converts mechanical motion into electricity which feeds into the circuit block to run an ultra-energy efficient IC (integrated circuit) and quartz oscillator to control the high-accuracy timekeeping of ± 15 seconds per month.

How it works

1. The spring uncoils to turn the rotor at the speed of up to 16 turns per second for about 10 to 15 seconds.
2. With the rotor turning, the coil starts to generate the electricity.
3. Once the circuit block receives the electricity, it acts as a brake function to control the rotor spinning speeds to spin 8 turns every second. (This unit is equivalent to a mechanical watch’s escape wheel, pallet, balance wheel and hairspring functions, which has the vibration of 28,800 per hour.
4. The rotor turning does not only generate electricity, but it also gives the information of its spinning speed to the circuit and also works as the physical timing control.
5. When the spring is fully wound, it keeps the watch running for two to three days.

SEIKO SPRING DRIVE FEATURES

Spring Drive is unique because, while it has nearly all the characteristics of a classical mechanical watch, it does not require an escapement. The escapement uses the back and forth motion of a balance wheel to regulate the speed at which the spring drives the hands and it is this high-friction motion that makes the traditional mechanical watch vulnerable to inaccuracy and damage. The genius of Spring Drive is that all the motion in the movement is in one direction, so that the friction is all but eliminated. It is also this one-way motion that allows the hands to move with the unique glide-motion that reflects the real nature of time. Spring Drive is a natural revolution in timekeeping.

AUTOMATIC SPRING DRIVE

During Switzerland’s Basel Fair in the spring of 2005, Seiko unveiled its latest innovation of an automatic wind Spring Drive timepiece. The company has been working to perfect the movement for 28 years, having started on the project shortly after creating the world’s first quartz watch, the Astron, in 1969.

According to Seiko’s press announcement at Basel, the new timepiece brings four advantages over typical automatic winding watch movements.

- The Seiko Spring Drive offers 72 hours of power reserve, whereas most watches offer about 40 hours.
- Seiko Spring Drive winds 30% faster than a conventional movement.
- Spring Drive movements are accurate to about 1 second per day.
- No more jerky "ticking" motion - the second hand flows smoothly around the dial.

At first, I wondered how different the Spring Drive movement is from the Seiko Kinetic which also gets its power source from the automatic rotor (oscillating weight). In the Kinetic movement, the power is transferred to a ‘capacitor’ which then is further transmitted to the train wheels. However, the Spring Drive, while also receiving its power from the automatic rotor - by the motion of the wrist -, that power winds up a mainspring (just like in a normal mechanical watch). In fact, the 'complete automatic winding unit' closely resembles that of many automatic mechanical movements made by Seiko and other users of Pellaton type winding systems.

The Seiko Automatic System



One of the favorite features of Seiko mechanical automatics, as illustrated by fellow watchmaker John Davis in his own separate review of the Seiko Divers watch, is the Magic Lever winding system.

Earlier versions of this winding system involved only three moving parts: the rotor, the Magic Lever and the pawl wheel. Current implementations use one extra wheel for a total of four moving parts. This simplicity of design adds to its robustness while maintaining a high level of functionality. Along with the lack of manual winding, it makes the 7S26 movement (shown) one of the simplest automatics around. The basic functioning of the Magic Lever system can be understood from these diagrams from a Seiko Credor catalog. The coupling between the lever and the intermediate wheel functions on the same principle as a locomotive (or a choo-choo as shown in the diagram). The two arms of the Magic Lever then drive the pawl wheel. They alternately pull and push the pawl wheel in the counterclockwise direction as the intermediate wheel rotates in conjunction with the rotor.





The new 5R65 Spring Drive Automatic Movement



TRAIN WHEELS OF NEW SPRING DRIVE MOVEMENT



In order that the entire power generated through the oscillating weight to the mainspring is not prematurely expended and is regulated at the same time, Seiko employs, in place of a mechanical escapement, a newly developed “Tri-synchro regulator”. This unit regulates the ‘mechanical energy’ used in the Spring Drive mechanism; the ‘electrical energy’ generated from the mainspring’s motion which activates a crystal oscillator; and the ‘electromagnetic energy’ that turns the glide wheel precisely 8 times per second. It required new advances in electro-magnetics to develop the braking system within the regulator and new advances in power generation and IC to convert part of the mainspring’s mechanical power to an electrical signal.

I believe the achievements found in the Seiko Spring Drive are, in general, obvious but noteworthy on many fronts.

First, detailed attention has been given to the finishing and aesthetics of the movement parts not only for its looks but also to make all the moving parts operate as smoothly as possible. As for just beauty, not many quartz movement makers bother to produce a high end looking product.

Second, the idea of combining the proven side of mechanical watchmaking with the latest innovations in quartz technology is a noble undertaking and, indeed, a significant accomplishment.

Third, the enormous collective resources of Seiko’s financial, technical, and engineering all contributed to this astounding and impressive breakthrough.

Perhaps the most remarkable feat of accomplishment with this unique hybrid of quartz-mechanical is the less than a handful of non-traditional parts that are never used in all mechanical movement. Out of 280 parts in the Spring Drive movement there are only four ‘electronic’ parts representing less than 2 percent of the total number of components.

Its technological advances, as listed on Seiko’s website (see link below) are many and varied, as its numerical statistics reveal:

* 0.025 mm. The thickness of each layer of alloy in the coil block.
* 1 second a day accuracy, 10 times better than the chronometer mechanical standard.
* 3 types of energy are controlled by the Tri-synchro regulator: mechanical, electrical and electro-magnetic.
* 5 craftsmen and women. Only Seiko’s 5 most skilled craftsmen and women are entrusted with the assembly of Spring Drive.
* 8 times per second. The precise speed at which the glide wheel turns within the electro-magnetic braking system.
* 13 generations of prototype were built in the development phases.
* 15 microns . The width of the wire in the Tri-synchro regulator’s coil.
* 18 layers of amorphous alloy in the coil block.
* 25 nanowatts. The minute amount of power needed to activate the regulator, less than half that needed in all other watch circuits.
* 28 years of research and development invested in the project.
* 30 percent improvement in winding efficiency achieved through the improved Magic Lever system.
* 30 jewels in the movement. 32 in the small second hand version.
* 72 hours of power reserve.
* 92 years since Seiko built its first wristwatch.
* 124 years of Seiko's expertise in time keeping.
* 230 patents have been applied for in Japan, USA and the EU.
* 276 components in the movement. 280 in the small second hand version.
* 600 actual prototypes were built between 1997 and 2004.
* 25,000. The number of times the coil is wound, for maximum energy efficiency.
* 28,800. The number of times the glide wheel turns per hour.

SUMMARY OF DIFFERENCES BETWEEN THE NEW ‘AUTOMATIC’ SPRING DRIVE AND ITS PREDECESSORS

1. The new Spring Driver is an automatic wind versus the previous one a manual wind.

2. The principle technical function of the new and old spring drive are the same except the new spring drive has additional automatic mechanism parts.

3. The Magic Lever winding system parts have been reduced by one wheel since the new type mainspring requires less power, thus providing for smoother and more efficient winding

Seiko claims the system combines the best of mechanical and quartz technologies while doing away with the negatives of each.

It replaces the weakest component of a traditional mechanical watch - the escapement - and the one part of a quartz watch which wears out - the battery.

Crucial to the mechanism has been the creation of a mainspring using a high-elasticity material called Spron 510 which delivers more power for longer to the movement.

As the watch unwinds it powers a rotor which produces enough electricity to cause the quartz crystal to give out a reference signal to an integrated circuit which replaces the escapement and regulates the three kinds of energy used by Spring Drive.

This allows the hands of a Spring Drive watch to move in a smooth, sweeping action - rather than in a series of ratchet-like steps - making it, according to Seiko, the only watch in the world to represent the true motion of time.




It is the opinion of Seiko's management that their SPRING DRIVE technology has "created the de facto standards of the watch industry". One thing is sure - Seiko has proven to the watch industry that it is, indeed, not a sleeping giant.


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The writer acknowledges thanks, first and foremost, to Scott Chou - Technical Service Manager of Seiko Time Corporation in the U.S.A., and also to John Davis, as well as Thomas Mao, Andrew Babanin (photo taken at Basel Fair ‘05), Mike Disher and to others for information gathered to cover this report.

At this writing, no other official technical materials were available from Seiko U.S.A. on the new Spring Drive.

ADDITIONAL INFO FROM SEIKO
by Jack Freedman

Hi all,

Official information from Seiko about the Spring Drive Automatic timepiece has been sketchy and incomplete. Today I talked to a technical spokesperson at Seiko who took the time to answer a few questions I was asked by many forum participants.

Disclaimer
Please note that these questions and answers have not been recorded verbatim and that they were edited and modified by me for the purpose of general information and discussion.

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Question #1
The Grand Seiko Spring Drive Automatic with a 9R65A movement was introduced last year in Japan. Grand Seiko calibers are all 9 series these days. How does the 5R movement compare with the 9R65A movement used in the Grand Seiko Spring Drive watches which were introduced in 2004? Is the 5 series designation pure marketing or are there some functional differences?

Answer

Here's an official e-mail reply I got from Seiko’s U.S. executive offices on May 17, 2005:
I have the exact quote from an expert in our Tokyo office regarding your movement question pertaining to Spring Drive.
The 9R65 movement is used only for Grand Seiko. The only difference between 9R and 5R is the finish of the rotor bridge and shape of the rotor. As an example, striped pattern bridge for 9R and circular pattern for 5R. Processing method and time are same so it is difficult for us to judge which is better between them. However, in terms of technical modifications and improvements 9R and 5R is same.
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Question #2
What is the expected life of the IC and generator?

Answer
The longevity of these components are not much different than those in other quartz movements. And, many quartz movements 25 years old are still around with the original electronic parts. If the watch is not dropped or abused in any way there should be no problem with these parts functioning over a long period. Furthermore, since the Spring Drive contains no battery there is no chemical process which could unexpectedly have an adverse effect on the IC and generator.
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Question #3
What are the specs of these models i.e. size, height, weight etc. ?

Answer
Seiko's marketing department has not yet officially released all information on these new models.
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Question #4
When will these watches be available in the U.S. and at what price?

Answer
The expected release will be this summer through select stores at the price of $3500 for the steel version. It will also become available in gold. The prices are justified by the very high quality components used and by the significant amount of manual assembly by highly skilled watchmakers.
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Question #5

How many watches will be produced initially for the market?

Answer
Seiko estimates they will produce fewer than 1000 Spring Drive watches during the first year. Seiko’s 5 most skilled craftsmen and women entrusted with the assembly of Spring Drive should be able to handle the initial production.
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Question #6

How complicated is this movement that it needs specialized technicians to do the assembly work?

Answer
It may be possible for a qualified professional watchmaker with good skills and experience to disassemble, service, and reassemble the movement without the fear of facing the unknown.
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Question #7
What are the recommended service intervals for these new timepieces?

Answer
Seiko's preliminary tests and research show that the movement should run longer between complete service overhauls than other mechanical and quartz movements. There is no 'escapement' heavily dependent on the condition of lubricants and no 'power cell' to require a battery change and which can cause leakage, corrosion, and damage to the movement. Seiko has not specified at this time precisely how often the watch should be serviced.
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Question #8
Will the spring drive eventually replace the kinetics movements?

Answer
Seiko has not made their marketing or production plans public. It's hard to predict the future trend but, at the moment, there exists a need to also continue to produce and market the lower priced Seiko 'Kinetics' timepieces and that niche will be filled.
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CONCLUSION

I thank Seiko and all the participating readers of the forum who have contributed to this discussion and appreciate all your kind comments about my review.

I conclude this additional posting with the appropriate words of a forum member who wrote:

"I think I may be able to see it as Jack does. The problem with existing quartz watch technology is that it does not build on the heritage we admire, but discards it and replaces it with something that is no more interesting to me than any other piece of electronics. In contrast, the Spring Drive respects this heritage and builds within its traditions. It can be seen then as a technological advance in horology per se rather than a repudiation of horology." (Very well said, Bogart! - Jack)


Regards,
Jack Freedman



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