The "Delta Mark" (Triangle) Cases And Finally What It Means!
Sept 10, 2018 8:47:41 GMT -8
Post by Accutronitis on Sept 10, 2018 8:47:41 GMT -8
Some people know that the delta mark (triangle) means a transitionary period starting late 1963 and ending early 1964 but now I know what Bulova changed and why !
With all Accutron 214 watches, The case bezel has a lip...
That lip is meant to stop the Dial/Movement from falling through the bezel, On almost all 214 movements the dial is supported by the pillar plate and the dial is "pinched" between the bezel lip and the pillar plate...
BUT An Accutron Astronaut watch is different because the dial no longer rests directly on the pillar plate because the 214HN has a gap between the dial and the pillar plate and the dial is no longer supported by the pillar plate ...
Which is because of the added 4th GMT hand needs one more gear added to the stack of 3 gears and to make room for that extra gear the dial must be "Shimmed" away from the pillar plate by use of a "dial shim"...
So now without the dial being supported all the way out to the edge if the movement was pushed in too hard the dial would dish ever more and could push right by the lip in the bezel that was supposed to stop the Dial/Movement at the lip...
How little the lip made contact with the dial in the 1st gen Astronaut cases can clearly be seen below with this picture of a factory original 1962 1st gen "Astronaut" dial !
The difference in lip size is very easy to see under the 40x power microscope !
Before the transition the original small lip...
And after the transition the much larger lip...
So it's clear the fix was to make the lip in the bezel larger, So the transition was from a small bezel lip to a larger bezel lip and thus the "Delta Mark" case was born !
With all Accutron 214 watches, The case bezel has a lip...
That lip is meant to stop the Dial/Movement from falling through the bezel, On almost all 214 movements the dial is supported by the pillar plate and the dial is "pinched" between the bezel lip and the pillar plate...
BUT An Accutron Astronaut watch is different because the dial no longer rests directly on the pillar plate because the 214HN has a gap between the dial and the pillar plate and the dial is no longer supported by the pillar plate ...
Which is because of the added 4th GMT hand needs one more gear added to the stack of 3 gears and to make room for that extra gear the dial must be "Shimmed" away from the pillar plate by use of a "dial shim"...
So now without the dial being supported all the way out to the edge if the movement was pushed in too hard the dial would dish ever more and could push right by the lip in the bezel that was supposed to stop the Dial/Movement at the lip...
How little the lip made contact with the dial in the 1st gen Astronaut cases can clearly be seen below with this picture of a factory original 1962 1st gen "Astronaut" dial !
The difference in lip size is very easy to see under the 40x power microscope !
Before the transition the original small lip...
And after the transition the much larger lip...
So it's clear the fix was to make the lip in the bezel larger, So the transition was from a small bezel lip to a larger bezel lip and thus the "Delta Mark" case was born !