A 4K video series brought to you by webChronos, "Discovering the World of Luxury Watches through Sound," will move watch lovers and sound lovers around the world to tears! Enjoy the sounds of timepieces while savoring the beautiful movements and movement of the hands in 4K resolution. Perfect for background music while you work, or as a companion for your after-work drinks, this video introduces two chronometer pocket watches. Headphones recommended.
The driving sound of the detent escapement is clearly different from that of a Swiss lever.
Filming and editing: Masato Yoshie
The beauty of British chronometers
This episode of "Discovering the World of Luxury Watches through Sound" features a listening comparison between a chronometer pocket watch from John Bennett, a London-based watch brand founded by the 19th-century John Bennett, and an unsigned British-made chronometer pocket watch. The beat sound produced by the detent escapement is clearly different from that of a Swiss lever escapement and is well worth a listen.
Although they both use detent escapements, their construction is different: the John Bennett uses a "spring detent system" that uses the elasticity of a leaf spring to advance the escape wheel teeth, while the unnamed chronometer uses a "pivoted detent system" that controls the escape wheel using the elasticity of a spiral spring similar to a balance spring.
One way to enjoy the videos is to compare them and discover the differences. For example, the mainspring winding method. While unsigned chronometers use the classic key-winding method, Bennett uses a hybrid of key and crown winding. It's also fun to think about why Bennett chose to keep the key-winding method.
The unsigned chronometer, which reveals much of the movement, including the chain pull mechanism, thanks to the split bridges unique to the Lépine movement, and the British-style John Bennett, which covers most of the movement with the bridge, are sure to immerse you in the world of chronometer pocket watches.
Sightseeing spots
0:15 Various crown winding methods ←Attention points!!
0:35 John Bennett Dial Pull Rotate
0:49 John Bennett Movement←Attention points!!
1:04 Unsigned chronometer dial, rotates by pulling
1:08 Unsigned chronometer movement←Attention points!!
1:31 Unsigned chronometer guilloché←Attention points!!
1:35 John Bennett Dial←Attention points!!
1:50 John Bennett Case Detail Cut
1:59 John Bennett detent escapement close-up←Attention points!!
2:05 Unsigned chronometer dial
2:14 Unsigned Chronometer Detent Escapement Close-up←Attention points!!
2:36 John Bennett full cut
3:05 Unsigned Chronometer Full Cut
What is a detent escapement?
Also known as the chronometer escapement, it was invented in 1765 by French watchmaker Pierre Le Roy. In addition to its small constraint angle, which allows for high isochronism, the contact surface between the pallet jewel and the escape wheel is small, and if the design is excellent, it requires almost no lubrication. It can also drive a larger balance wheel than a Swiss lever escapement. On the other hand, it is prone to "over-swing," where the balance wheel swing angle becomes too high, and it easily stops when subjected to impact. Also, due to the large positional difference, it is rarely used in portable watches. Audemars Piguet's AP escapement and Jaeger-LeCoultre's Ellipse Isometer escapement (both in 2007) are included in the broad definition of detent escapements, which have improved upon the shortcomings of the detent escapement. The co-axial escapement developed by Omega (1978, commercialized in 1999) can also be considered an escapement based on detents. (webChronos Watch GlossaryThan)
