Here is a little piece I wrote on the Maniflex some time ago. The seed for discussion is a French sideswiper called the Maniflex. This one was made by Dyna c. 195Ø.
Take a look at http://www.metronet.com/~nmcewen/FKG-images/Dyna-Maniflex-sideswiper.jpg
An ad for the Maniflex: http://www.metronet.com/~nmcewen/FKG-images/Dyna-Maniflex-sideswiper-ad.jpg
The word Maniflex has an interesting derivation. It is the combination of 'mani' and 'flex'. 'Mani' come from the french word for key, 'manipulateur.' 'Flex' comes the french work flexible having the same meaning as it does in english and refers to the flexibility of the lever blade.
There is no french equivalent for 'sideswiper' so these keys are called ""Lame de scie" (meaning hacksaw blade), or "manipulateur horizontal". Besides Dyna, there was another French sideswiper called the "DOUBLEX", made by the same maker as the "VIBRO-MORS" bug, but seem to fairly uncommon.
Dyna's founder was A. Chabote. He began his career working for Pericaud, the famous wireless manufacturer in 19Ř9, where he designed the first crystal set for them. After WWI, Chabot became president of Pericaud. In 1921 he founded "A. Chabot" with trademark "Dyna." The company produced various radio equipment for both amateurs and professionals. In ads from 194Ø to 1977 the address was listed as 36, Avenue Gambetta, PARIS.
The Maniflex shown above is the 294Ø6 T: Standard model, aluminum (black or gray painted) base, tungsten contacts, maximum voltage 23ØØVolts @ 5ØHz, with nickel plated parts. This model seems to be not rare, but not common in France.
Besides the 294Ø6 T there was the 294Ø8 T (1942) "Maniflex ŕ contacts TAR", (with TAR contacts), "TAR" stands for "Transmission ŕ réception" (transmission to reception). It is the same model as shown above with an extra set of contacts switching an antenna change over relay. When the blade of the key is at rest the antenna is connected the receiver and disconnected during keying. No such pieces are know to exist in collections.
The French seem to be rather avid users of sideswipers at one time. I'll say no more on this and let Don, K8MFO give you his take on the French and sideswiper.
Thanks to Yann Conan and Wyn Davies for helping with info on the Maniflex.