One of the rarest model of Shanghai 7's series.
It carries the 7's series movement with quick-set date-just function same as swiss watch. It means, pulled out the crown in a half way to have date adjust. Had only found lot "7220-101" has this function and very seldom to find in the second-hand market.
The finial standardlize model of 7's. It could be found both calender and non-calender models of SS7 sharing the same back-case. I would say this is the finial and the latest model of SHW factory made SS7's "Tongji". Since the quick-set date-just system of the preview models, 7221,7621... are so fragile, it turns factory to made a low-tech but more reliable canlandar seting system. Date adjusted by pulling out the watch stem in a halfway, keep turning the minutes hand forward to 12 o'clock and backward to 9 o'clock position to have the date-just.
SS7 case back are very common found in the maket.
It carries a quartz 32768hz of DSE movement with "prototype" marked on the case back.
Quoted from Shanghai Light Industry Bureau web-page about this watch, URL as follow
"The First China made "3rd generation" quartz watch was made by Shanghai Watch & Clock Parts Factory. By the early 1972, SH W&C Parts Factory made the 1st prototype operated by 4x 1.5V #5 battery. By the end of 1974, made a 16 beat frequency circle movement prototype. Till to 1984, 4,177 piece of prototype had made, registered "JinXing" as the trade mark. In order to let SH W&C Parts Factory more concentrated on quartz movement invention, JinXing stopped their production on December of 1984."
As per the Bureau recorded, the terms of 1,2,3 generation;
1st generation quartz watch = Electronic -Mechanical watch, made by Shanghai Ball Pen Factory named "XiongYang".
2nd generation quartz = Tuning Fork watch (Not sure which factory did the first, I know Tianjin and Shanghai, both watch factory had made their tuning fork watch in the past as for experimental purpose),
3rd generation quartz = real quartz watch movement, power by battery and time taking by quartz vibration.
It comes with the original 19J calander watch dial casue it's a prototype
The bezel has been modifield from fragile plastic to metal (look like copper) and carries an SS4 alike unmarked screw-down crown.
Typical SH watch case-back with very unusal engraving.
First role: Quartz Calandar Diving S-Steel Anti-magnetic
Bottom: Shanghai City Watch & Clock Reserach Centre
He’s agreed my point of view, based on the launching time and the existing sample of model A-631 ladies watches, the time line of the factory using complicated form of “Zuan” on their products was about 1964. But why did they change? I need more evidence…
He stated that there was a Govenment Notice issued on 60’s to announce the new regulations on using simply Chinese words, or I can find out something from this announcement.
After searching the internet, I found that on 7 March 1964, Chinese Government - Chinese Words Revolution Committee, National Culture Bureau, National Education Bureau (中国文字改革委员会 中华人民共和国文化部 中华人民共和国教育部) had published an announcement on standardize of using simply Chinese words “《关于简化字的联合通知》” to public. On its appendix, “Simply Words General Chart 《简化字总表》”- Chart 1, I found the word “Zuan” in both simply & traditional Chinese there……. So, it’s all cleared!!!