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Straps for Vintage Fixed Wire Lug Trench Watches or Officer's Wristwatches



Keyless Work

Copyright © David Boettcher 2005 - 2024 all rights reserved.

The first watches were wound and set by a separate loose key. A common arrangement is for the mainspring to be wound from the back and the hands set from the front. The mainspring is wound by passing the key through a hole in the inner case back and onto the square end of the fusee arbor, or the barrel arbor in going barrel watches. Turning the key winds the spring. To set the hands the front bezel is opened and the key is applied to a square on the boss of the minute hand. Turning the key moves both the minute and hour hands.

Using a key to wind and set a watch has numerous disadvantages: the key can get lost, the hole in the case back for the key lets in dust, and the dial or hands can easily be damaged during setting.

To overcome these problems, means were invented that allowed the watch to be wound and set using a button or crown on the end of the pendant, the tube that projects from the case and carries the bow. This meant that a separate loose key was not needed so such watches were called “keyless”. Today almost all watches are keyless and it is only antique watches that are key wound so the term keyless has fallen out of use. In Swiss / French a keyless watch was denoted by the term “Remontoir”.

Keyless watches usually have a crown on the end of the pendant or at the side of the case which is used to turn a shaft called a stem. The stem carries the action of turning the crown into a mechanism inside the watch movement which translates the turning action into winding the mainspring or setting the hands. This is called the “keyless work”. The keyless work shifts wheels into and out of mesh so that the different functions of winding and setting can be performed by turning the crown.

There many designs and patents for different keyless works. Thomas Prest, an apprentice, journeyman and then foreman to John Arnold the chronometer maker, was one of the first to design a movement with keyless winding, applying for a patent that was granted No. 4501 date 20 October 1820 for "A new and additional movement applied to a watch, to enable it to be wound up by the pendant knob without any detached key or winder". Prest's design was only applied to movements with a going barrel so it found little favour with English watchmakers, who continued to prefer fusee movements to which it was very difficult to apply keyless winding.

In Switzerland, Louis Audemars invented a form of keyless winding in 1838. In Britain, Adolphe Nicole devised keyless work for both going barrel and fusee movements, for which he was granted British patent No 10,348 in 1844. Nicole initially worked in Switzerland as a partner in the company Nicole & Capt, setting up a London branch in 1840. When Jules Capt died in 1876 Nicole took on the Dane Sophus Emil Nielsen as partner and the company became Nicole, Nielsen & Co. This company produced many of the finest London watches nineteenth century.

The usual European style of winding and setting requires the stem to be connected to the keyless work by the setting lever. To secure the setting lever in place requires turning a small screw called the setting lever screw. This is fiddly and requires an eyeglass, a small circa 0.5mm screwdriver, and a steady hand to avoid marking the screw or surrounding plate.

In America, the watch movement and case were often brought together only at the point of sale. A customer could choose which movement he wanted and which case he wanted, and the movement would be put into the case in the shop. This needed to be easily done without requiring a workshop or tools, so a type of keyless work called “negative set” was invented by Duane H. Church of the American Watch Company of Waltham in 1892. This was granted US patent number 280,719 on 3 July 1883. With negative set keyless work there is no setting lever screw and a movement can be easily and quickly put into and taken out of a case. From 1861 to 1994, American patents protected an invention for 17 years from the date of grant of the patent.

Stem Set

All watches that are wound with a crown are “stem wound”; the term “stem set” refers to the ability to set the hands using only the crown, by pulling the crown away from the case.

There are other ways of changing the keyless work from winding to setting mode such as pin set and lever set; these are described in separate sections below. Although these allow the time to be set by turning the crown, they are not usually referred to as stem set.

There are two basic types of keyless work that are used to change between winding and hand setting mode; rocking bar and sliding pinion, also called sliding or shifting sleeve. Both rocking bar and sliding sleeve works can be operated by the crown moving the stem, called stem set, by a push piece on the side of the case, called pin set, or by a lever.

Rocking Bar and Sliding Pinion

Sliding pinion keyless work
Sliding Pinion keyless work: Mouse Over to Operate

Rocking Bar keyless work: Click image to enlarge

The rocking bar work is conceptually simpler, and is the older of the two. The sliding sleeve work was invented in 1844 by Adrien Philippe.

In 1844 Adrien Philippe, who later joined the company of Count Patek and which subsequently became Patek Philippe, invented the modern form of sliding pinion keyless work for which he was granted British patent No 10,348 in October 1844 and French Patent No. 1317 for “Mechanical system or device for winding and hand setting of watches via the pendant” in 1845. This work is found in almost all keyless watches from the late nineteenth century onwards.

Two pinions sit on the stem, the winding pinion and the sliding pinion. On the mating faces of the two pinions are inclined teeth that form a Bréguet ratchet - it is the teeth of this ratchet slipping over each other that you feel when you are winding a watch and turn the crown backwards.

The sliding pinion sits on a square section of the stem and is normally held in contact with the winding pinion by the yoke and a spring, called the yoke or return spring. The winding pinion sits on a round part of the stem. It doesn't move along the stem and can only be turned through the setting pinion. This is so that when the keyless work is in the hand setting mode, turning the stem doesn't turn the winding pinion.

The square on the stem means that when the crown is turned, the sliding pinion turns and, through the Bréguet ratchet, turns the winding pinion so that turning the crown winds the watch.

To set the hands, the yoke moves the sliding pinion along the square section of the stem so that it disengages from the winding pinion and teeth on its end face engage with the setting wheels.


Badly worn stem bearing

There are broadly two ways of moving the yoke; either directly by pressing the pin set push piece, or by pulling out the crown when a setting lever moves the yoke. The setting lever engages with a groove on the upper part of the stem so that it turns around a screw when the stem is pulled out or pushed in.

The large image above shows a stem set sliding sleeve work from a Marvin watch movement. If you mouse over it you should see the action of pulling out the stem to put the keyless work in the set hands mode.

In the normal position, when the crown is turned, the sliding pinion also turns, driven by a square section of the stem below the winding pinion. The sliding pinion then turns the winding pinion through the Bréguet ratchet that couples the two pinions. The winding pinion drives the winding wheels, the crown and ratchet wheel, which turn the barrel arbor and wind the mainspring.

When the stem is pulled out, the setting lever, which engages with a groove on the stem just above the winding pinion, presses down the yoke, which makes the winding pinion slide down the square section of the stem. This engages the teeth on the end of the sliding pinion with the intermediate setting wheels that connect to the motion work. Turning the crown then causes the motion work to turn, moving the hands.

Despite the efforts of numerous inventors over centuries, the keyless work remains the worst designed part of a watch from the point of view of lubrication and longevity, and many watches have been scrapped over the years because of wear in the winding work, especially where the stem bears in the plates. The photo here shows a stem bearing that is badly worn because the owner didn't have the watch serviced regularly. Wear like this can make it impossible to wind or set the watch, and can be expensive or impossible to repair. From this point of view, automatic or self winding is a benefit in a watch for everyday use. Key wound watches don't have this problem. If you have a manual stem wound watch, bear this in mind and have it cleaned and oiled regularly to avoid problems like this.

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Pin Set (Nail Set)

FontKeylessPinSet
Pin Set work
Pin set
Pin Set or Nail Set

Pin set, or nail set, is an alternative to stem setting for putting the keyless work into the hand setting mode. With pin set, the crown remains in its normal position against the case during both winding and hand setting. Pin set is seen on nineteenth century pocket watches, and also on early wristwatches.

Pin set uses a pin on the side of the case band, the middle part of the case, usually set into a small olivette near to the crown, to engage the hand setting mode. One of these is indicated by the red arrow in the picture. With the pin in its normal position, turning the crown winds the mainspring. To set the hands, the pin is pressed in (usually with a fingernail, hence the alternative name) and turning the crown then sets the hands.

The second picture shows a red item which represents a small cylinder of metal in contact with a shoulder on the yoke. When the pin and the red cylinder are pressed inwards, the yoke is pushed downwards, carrying the sliding pinion with it. The teeth on the end of the sliding pinion engage with the intermediate setting wheel so that turning the crown moves the hands. When the pin is released the work is put back into the winding position by the spring on the left of the image.

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Lever Set

Lever Set
Lever Set: Click image to enlarge

Lever set is another alternative to stem setting for putting the keyless work into the hand setting mode. With lever set, the crown remains in its normal position against the case during both winding and hand setting. Lever set is seen on nineteenth century pocket watches, on early wristwatches.

Lever set is an alternative form of setting that is similar in concept to pin set. Instead of pressing in a pin, a lever is pulled out to engage hand setting. This lever is often covered by the watch bezel, so the front cover of the watch must be opened to operate it. The lever must be pushed back into place, disengaging hand setting, before the bezel can be closed. Lever set was required by American railway companies to make it almost impossible to set the hands accidentally, after a serious railway accident was thought to have been caused by this happening.

The pin or lever set work is more robust than the stem set work, which is actuated by a small projection from a setting lever that engages with a groove on the stem. Because these parts are small and not well lubricated, they often wear and cause problems, such as the stem pulling out completely when the wearer tries to set the time. The pin set and lever set works don't suffer from this problem. However, by the 1920s pin and lever set were seen increasingly as old fashioned and were phased out in favour of stem set.

Pin set and lever set works can be used equally well with either rocking bar or sliding sleeve keyless work.

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Negative Set or “American” Keyless Work

Negative set sleeve
Negative set detent spring sleeve
Land & Water case
Case Stem and Detent Sleeve: click image to enlarge.

Negative set keyless work was most used in America because watch movements and watch cases were often sold separately, so that a customer could choose which movement and case they wanted. This meant that it had to be easy for the retailer to fit a movement into a case at the point of sale. Negative set keyless work allows a movement to be easily removed from its case and put into another case.

In a watch with negative set keyless work, the winding stem is in two pieces; one part in the movement and the other part in the case. The stem in the movement has a square socket in its outer end into which a square on the end of the case stem can enter. This connects the two parts together so that turning the crown turns the case stem and the movement stem. The case stem cannot pull the movement stem outwards, it can only push it inwards.

Because the case stem cannot pull the movement stem outwards, negative set keyless work is spring biased towards the hand setting mode. This is the mode the keyless work adopts when nothing is pressing on it, such as when the movement is out of the case. Pushing the movement stem into the movement puts keyless work into winding mode.

The keyless work is normally kept in winding mode with the crown against the case by a detent in the stem tube of the case.

To put a negative set movement into a case, the crown is pulled out and the movement inserted into the case. When the crown is then pushed in, the case stem engages with the movement stem and the keyless work into winding mode, which is where it remains unless the crown is pulled out to set the hands or remove the movement from the case.

The images here show a case stem detent assembly and a cross section through the pendant of a watch with negative set keyless work. The short case stem, or American stem, is fitted in the pendant or stem tube of the watch case. This case stem is not attached to the movement. When the movement is in the case, the square section on the end of the case stem engages with a square socket on the end of a short stem in the movement.

When the movement is put into the case, the crown is pushed inwards and the case stem pushes the keyless work into the winding position. This is against the bias spring in the keyless work, so a detent in the pendant or stem tube holds the case stem in this position whilst the watch is in normal use.

The detent that holds the case stem in positions is formed by grooves in the stem, and a split spring steel sleeve coloured grey in the image. The sleeve is split at its lower end to form four claws that grip the stem. The spring sleeve is held in place by an externally threaded brass plug that is coloured yellow. In the image the case stem is in the normal winding position although the movement is not shown. When the crown is pulled out the claws of the sleeve are forced open by a taper to allow the swelling on the stem to pass, and then they grip the groove in the stem below the swelling and hold the crown in the hand setting position.

When the crown stem is pulled out into the hand setting position, the bias spring pushes the keyless work into the hand set position - the stem doesn't pull the keyless work into the hand set position. The keyless work is put into hand set mode by the spring when it is not held in winding mode by the crown stem, so the action of putting the keyless work into the hand set mode is by removing something which is stopping it, a negative rather than positive action, hence the name negative set.

Movements made by Tavannes sometimes have negative set keyless work and are engraved "US Pat 24 May 1904", reference to patent US 760647 for a negative set stem winding and setting work (keyless work) granted to Sandoz on that date, a US version of a Swiss patent that was granted to Sandoz in 1903.

If you have any comments or questions, please don't hesitate to get in touch via my Contact Me page.

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Copyright © David Boettcher 2005 - 2024 all rights reserved. This page updated January 2024. W3CMVS. Back to the top of the page.