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BALANCE JEWELS IN WATCHES

This page shows eight micro-photographs of damaged balance jewels.  It also shows damage done to balance staffs along with an illustration of a perfect pivot and oil stop on a staff.

Jewels serve many useful purposes in watches.  They are used to reduce friction on pivots, allowing the gear train to run with greater ease.  By reducing the amount of friction, less power from the mainspring is required, allowing a longer and finer mainspring to be used, thus creating watches that can run for over 60 hours on a single wind.  With jewels automatic wrist watches became available as the mainspring was allowed to slip within the mainspring barrel and still supply ample power to the gear train of the watch.

The use of jewels within a watch also serves the purpose of holding oil within the confined location of the jewel and gear pivot.  Prior to the use of jewels, watch movements were coated with epilene  which prevented the oils from spreading across the movement plates.

Jewels that are used in watches are precision made.  The pivot holes are precise thus allowing for matching parts to be produced with greater precision reducing the amount of time required in "matching" parts and assembling watch movements by hand.

In pocket watches and a few wrist watches, one will see about three types of jewel configurations.  There are pressed in jewels, using no setting around the jewel itself.  The donut shaped jewel is simply pressed into the watch plate.  Then we have gold jewel settings.  You basically see two types of these in watches.  There is the screw set types, where the jewels is held in a gold jewel setting.  It fits flush with the surface of the movement plate and is held in with two fine screws.  These screws are so small, that about 10,000 of them would be needed to fill a thimble.  Next you will see the raised gold jewel settings.  These appear on higher grades of watches.  Not only do they add beauty to the movement, but being raised above the surface of the watch plate, the pivots of the gear train can be longer adding greater strength and durability to the pivot.  The raised gold jewel settings also keeps oil away from the surface of the watch plates by holding the oil in a deeper cup.

The following micro-photographs were done by the Webb C. Ball Watch Co. of Cleveland, Ohio.  These were originally published in 1916.  These were distributed to Ball dealers for use in watch repair departments of these exclusive Ball watch dealers.  The original sheet was entitled "Micro-photographs Showing The Results of Bumping Watches."

The above is the original "Explanation" for the following
Micro-photographs.

Be sure to click on any picture for enlarged version

 

No. 1. Broken Jewel.

Showing the result of fall or bump.

No. 2. Cut Pivot.

Result of running in a cracked jewel, like 1, 3, 6 and 8.

No. 3. Broken Jewel, Piece Gone.

Watch can run in favorable position, but stops in reversed position.

No. 4. Bent Pivot.

Result of fall or bump.

No. 5. Pivoted Staff.

An ordinary job of pivoting, but far from perfect.

No. 6. Cracked Jewel.

Cracks running to hole. Such breaks might cut pivot very slowly.

No. 7. Perfect Pivot.

Perfect pivot with oil stop.

No. 8. Badly Cracked Jewel.

Sure to cut balance pivot, as in No. 2.

 

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