The Drinkless stinger patent
:: Kaywoodie ::
The early Drinkless Kaywoodies (Patent # 213598) from 1924 through 1931 had push bit stems.
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The Drinkless stinger with its four hole ball will keep this characteristic when integrated to the SynchroStem fitting.
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Pipes with screw-in attachment were produced from late 1929 with the "PAT. APPL FOR" stampings. A test of the design was conducted until 1931 when the SynchroStem patent was granted.
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▲ This stamping (allways on the underside of the pipe) easily dates the pipe to a very narrow timeframe: 1929 - 1931.