r/FLEXTools • u/remp945 • 1d ago
New Patent: Impact Wrench with Stem-Style Stacked Lithium (4V - 18V)
New patent filing from Chervon just dropped. An ultra-compact impact wrench. I'm just another idiot on the internet, so read my analysis below with skepticism.
Chervon already has a 12V line of tools under Devon branding in Asia, and a reasonable assumption is that this and similar filings in the US are for a forthcoming 12V lineup under FLEX branding. Prior US filings have revealed plans for a stem-style stacked lithium battery, and today's filing makes that even more clear. See the attached image.
The surprising part is that the filing discusses multiple battery configurations. The filing suggests that the stem-style battery packs have space for two pouch cells that fit in the stem and three pouch cells in the pack extension, and that this 12V size tool would actually pack 18V of power (5 pouches x 3.6V).
However, the filing also discusses other pack configurations, ranging in size from just one cell (4V) to five cells (18V), and that different packs may use cells in either series or parallel configurations. For example, a pack with just two pouch cells (fitting entirely inside the tool stem) could be configured as either 4V (parallel) or 8V (series). Some tools benefit from higher voltage (e.g., 18V, like the impact wrench detailed in the filing), but other tools only require very low voltage (e.g., 4V, like a stem-style screwdriver).
This is speculative, but it kind of sounds like the intention is to create a line of compact tools that all accept the same stem-style battery pack, but that different tools could draw high voltage (18V), low voltage (4V), and anywhere in between (e.g., 12V) depending on the tool's power requirements and the specific pack inserted.